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Purpose: To compare suture tape-augmented MPFL repair with allograft MPFL reconstruction using patellofemoral contact pressure and joint kinematics to assess the risk of patellofemoral over-constrainment at point zero.Methods: A total of ten fresh frozen cadaveric knee specimens were tested in four different conditions of the MPFL: (1) native, (2) cut, (3) reconstructed with tendon graft, and (4) augmented with suture tape. The patellofemoral mean pressure (MP), peak pressure (PP) and contact area (CA) were measured independently for the medial and lateral compartments using pressure-sensitive films. Patellar tilt (PT) and shift (PS) were measured using an optical 3D motion tracking system. Measurements were recorded at 0°, 10°, 20°, 30°, 60° and 90° of flexion. Both the tendon graft and the internal brace were preloaded with 2 N, 5 N, and 10 N.Results: There was no significant differences found between surgical methods for medial MP, medial PP, medial CA, lateral MP and PS at any preload or flexion angle. Significant differences were seen for lateral PP at 20° knee flexion and 10 N preload (suture tape vs. reconstruction: 1045.9 ± 168.7 kPa vs. 1003.0 ± 151.9 kPa; p = 0.016), for lateral CA at 10° knee flexion and 10 N preload (101.4 ± 39.5 mm2 vs. 108.7 ± 36.6 mm2; p = 0.040), for PT at 10° knee flexion and 2 N preload (- 1.9 ± 2.5° vs. - 2.5 ± 2.3°; p = 0.033) and for PT at 0° knee flexion and 10 N preload (- 0.8 ± 2.5° vs. - 1.8 ± 3.1°; p = 0.040). A preload of 2 N on the suture tape was the closest in restoring the native joint kinematics.Conclusions: Suture tape augmentation of the MPFL resulted in similar primary contact pressures and joint kinematics in comparison with MPFL reconstruction using a tendon graft. A pretension of 2 N was found to restore the knee joint closest to normal patellofemoral kinematics. [ABSTRACT FROM AUTHOR]

Purpose: The acromioclavicular ligament complex (ACLC) is the primary stabilizer against horizontal translation with the superior ACLC providing the main contribution. The purpose of this study was to evaluate the specific regional contributions in the superior half of ACLC, where the surgeon can easily access and repair or reconstruct, for posterior translational and rotational stability.Methods: The superior half of ACLC was divided into three regions; Region A (0°-60°): an anterior 1/3 region of the superior half of ACLC, Region B (60°-120°): a superior 1/3 region of the superior half of ACLC, and Region C (120°-180°): a posterior 1/3 region of the superior half of ACLC. Fifteen fresh-frozen cadaveric shoulders were used. Biomechanical testing was performed to evaluate the resistance force against passive posterior translation (10 mm) and the resistance torque against passive posterior rotation (20°) during the following the four conditions. (1) Stability was tested on all specimens in their intact condition (n = 15). (2) The ACLC was dissected and stability was tested (n = 15). (3) Specimens were randomly divided into three groups by regions of suturing. Stability was tested after suturing Region A, Region B, or Region C (n = 5 per group). (4) Stability was tested after suturing additional regions: Region A + B (0°-120°), Region B + C (60°-180°), or Region A + C (0°-60°, 120°-180°, n = 5 per group).Results: The translational force increased after suturing Region A when compared with dissected ACLC (P = 0.025). The force after suturing Region A + B was significantly higher compared to the dissected ACLC (P < 0.001). The rotational torque increased after suturing Region A or Region B compared with dissected ACLC (P = 0.020, P = 0.045, respectively). The torque after suturing the Region A + C was significantly higher compared to the dissected ACLC (P < 0.001).Conclusion: The combined Region A + B contributed more to posterior translational stability than Region B + C or Region A + C. In contrast, combined Region A + C contributed more to posterior rotational stability than Region A + B or Region B + C. Based on these findings, surgical techniques restoring the entire superior ACLC are recommended to address both posterior translational and rotational stability of the AC joint. [ABSTRACT FROM AUTHOR]

Background: Isolated medial patellofemoral ligament reconstruction (iMPFLR) is increasingly used for the surgical treatment of recurrent patellofemoral instability. Purpose: The purpose of this study was to identify the clinical and radiological predictors that can significantly influence the functional outcomes after an iMPFLR. Study Design: Case series; Level of evidence, 4. Methods: A total of 107 patients (112 ligament reconstructions) who underwent iMPFLR were evaluated with a mean ± SD follow-up of 59 ± 33 months (range, 12-123 months). Functional International Knee Documentation Committee (IKDC) and Kujala scores were assessed preoperatively and every 12 months. Radiological assessment of patellar height and tilt (Laurin angle, Merchant angle, Maldague classification) and computed tomography (CT) scan measurement of patellar tilt (contracted and relaxed quadriceps) and tibial tubercle–trochlear groove distance were performed preoperatively and at 6 months. Femoral tunnel position was assessed following the criteria formulated by Schöttle. The amount of femoral tunnel widening was measured by means of 3-dimensional CT scan at 6 months. Predictors were determined from univariate and multivariate regression analyses integrating clinical and radiological criteria pre- and postoperatively. The dependent variable was defined as the difference between pre- and postoperative scores. Results: Between pre- and postoperative measurement at last follow-up, a significant improvement for IKDC and Kujala functional scores was observed (Kujala: 57 ± 11.3 to 87 ± 12.9, P <.001; IKDC: 47.8 ± 13.1 to 79 ± 15.8, P <.001). Demographics (age, body mass index, sex), dislocation characteristics (number of dislocations, time between first dislocation and surgery, age at first dislocation, mechanism of first dislocation, knee side), clinical data (frontal limb alignment, hyperlaxity, recurvatum, pre- and postoperative range of motion), and complications (quadriceps atrophy, complex regional pain syndrome) did not influence functional scores. The predictors of lower improvement in functional scores included small correction of the patellar tilt reported on the CT scan measurement, malpositioning of the femoral tunnel, and a widening of this tunnel near the medial cortex. Malpositioning of the femoral tunnel was correlated with tunnel widening, and patients with anterior and proximal malpositioning experienced stiffness in flexion. Conclusion: Overall, iMPFLR demonstrated good outcomes. Predictors influencing the functional results were identified. Less improvement in clinical outcome was reported for patients with a high preoperative patellar tilt and only a small correction in tilt and for those who had femoral tunnel malpositioning, which was correlated with tunnel widening. [ABSTRACT FROM AUTHOR]

Purpose: A medial patellofemoral ligament reconstruction (MPFL) with an additional derotational femoral osteotomy is suggested for patients suffering from patellar instability and an increased internal femoral torsion (IT). This biomechanical study investigated whether an isolated MPFL reconstruction could restore patellofemoral biomechanics for 10° and 20° relatively increased internal femoral torsion.Methods: Eight fresh-frozen cadaver knees were tested on a specially designed knee simulator, which bend the knee from 0° to 90° flexion. Patellar motion (tilt and shift) and patellofemoral pressure (pressure shift, mean and peak pressure) were evaluated for 0°, 10° and 20° of IT with a native and reconstructed MPFL.Results: An isolated MPFL reconstruction, compared to a native MPFL with the same femoral torsion showed a significant medial shift of the center of force (10° IT p < 0.001; 20° IT p = 0.02) and patella shift (10° and 20° IT p < 0.001) but no significant change in patella tilt (10° IT n.s.; 20° IT n.s.) for 10° and 20° IT. There was a significant medial shift in the center of force for 10° IT (10° IT p = 0.04) and a non-significant lateral shift for 20° IT (20° IT n.s.) in comparison to the native MPFL with 0° of femoral torsion. Patella shift was directed medially for 10° IT (10° IT p = 0.002). In knee flexion angles up to 30°, the patella remained more lateral for 20° IT and showed a different motion pattern (20° IT n.s.). Patella tilt showed a significant lateral tilt for 10° and 20° IT (10° IT p = 0.01; 20° IT p = 0.002).Conclusion: MPFL reconstruction as an isolated therapy only appears to be reasonable for 10° increased IT. While for an increased IT of 20°, a lateralizing force vector remains and an additional femoral derotational osteotomy is recommendable. These findings may assist surgeons in the decision making of surgical procedures in patients suffering from patella instability. [ABSTRACT FROM AUTHOR]

Purpose: The choice of graft type in the anterior cruciate ligament (ACL) reconstruction remains a subject of controversy. The aim of this study was to assess the outcomes in ACL reconstructions performed using a four-strand hamstring tendon graft (4SHG) or a LARS ligament comparing the effectiveness of the two grafts at a medium follow-up of 8 years.Methods: This retrospective, single-centre, single surgeon study evaluated the clinical, functional and radiographic outcomes in 50 patients who underwent ACL reconstruction (25 4SHG and 25 LARS). Patients who underwent surgery after more than 6 months from injury and showed radiographically visible degenerative changes at time of surgery were excluded from the study.Results: None of the patients underwent re-surgery in the same knee. The range of motion of the operated knee, compared to the contralateral, was good for both groups. The anterior drawer test resulted negative in 21 patients (84%) in the LARS group and eight patients (32%) in the 4SHG group (P = 0.039). The Lachman test was negative in 19 patients (76%) in the LARS group and in 11 patients (44%) in the 4SHG group (P = 0.045). Although other results of ACL reconstruction measured by Lysholm scores, IKDC evaluation, Tegner scores and radiographic images showed using a LARS graft tended to be superior to using a 4SHG, there were no statistically significant differences calculated.Conclusion: Our results suggest that 4 years after ACL reconstruction using a LARS ligament or 4SHG dramatically improves the function outcome, while the patients in the LARS group displayed a higher knee stability than those in the 4SHG group. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of injury and treatment factors on clinical/functional outcomes in multiligament knee injuries (MLKI).Methods: Thirty-nine consecutive patients with confirmed and surgically treated MLKI who met inclusion criteria were scheduled for a follow-up visit to obtain: SF-12 and subjective feeling of normalcy between the operated and healthy knee, and IKDC, active range of motion (ROM), and stability exam (Lachman test, posterior drawer, and dial test at 30°). A chart review was used to obtain data on injury and treatment factors.Results: The postoperative mean (SD) outcomes were: IKDC score 62.7 (25.9), flexion-extension ROM 125° (29°), and percentage of normalcy 74% (20%). The postoperative normal/nearly normal stability exam was: Lachman test 36 (95%) patients, posterior drawer at 90° 38 (97%) patients, and dial test of 39 (100%) patients. There were 24 (61.5%) and 23 (59%) patients with complications and reoperations, respectively. The presence of bicruciate injuries was associated with worse Lachman (p = 0.03) and posterior drawer tests (p = 0.03). Presence of injury to meniscal structures was associated with worse Lachman test (p = 0.03), lower percentage of normalcy (p = 0.02) and extension lag (p = 0.04). Injury to cartilage structures was associated with worse IKDC scores (p = 0.04). IKDC was lower in cases of posterolateral corner reconstruction (p = 0.03) and use of allograft tendons for reconstruction (p = 0.02); ROM was lower in allograft reconstruction (p = 0.02) and need for meniscal repair (p = 0.01). Bicruciate reconstruction led to worst posterior drawer test (p = 0.006).Conclusions: The outcomes of MLKI might be negatively influenced by bicruciate ligament, meniscal, and cartilage injuries; with regards to treatment characteristics, need for posterolateral corner or bicruciate ligament reconstruction, use of allografts, or need for meniscal repair may similarly diminish outcomes. While surgical treatment provides good overall function, ROM and stability, it rarely results in a "normal" knee and the chances of complications and reoperations are high.Level Of Evidence: Cross-sectional comparative study, Level III. [ABSTRACT FROM AUTHOR]

Purpose: Valgus deformities of the lower extremity influence patellofemoral joint kinematics. However, studies examining the clinical outcome after treatment of patellar instability and maltracking due to valgus deformity are rare in recent literature. This study's purpose is to analyze the clinical results after combined distal femoral osteotomy (DFO) for treatment of patellar instability.Methods: From 2010 to 2016, 406 cases of patellofemoral instability and maltracking were treated. Twenty cases of recurring (≥ 2) patellar dislocations with genu valgum and unsuccessful conservative treatment were included in the study. A radiological analysis was performed, and anteroposterior (AP), lateral and long leg standing radiographs were analyzed, and the leg axis was pre- and postoperatively measured. At least 12 months postoperatively, the clinical leg axis, range of motion (ROM), apprehension sign, Zohlen sign, and J-sign were physically examined. Pain level and knee function were objectified on a visual analogue scale (VAS). The Lysholm, Kujala, and Tegner scores, re-dislocation rate, and patient satisfaction were also examined.Results: 20 combined DFOs on 18 patients with a median age of 23 years (15-55 years) were performed. The preoperative mechanical leg axis was 6.5° ± 2.0° valgus, and the mean tibial tuberosity to trochlear groove (TT-TG) distance was 19.1 ± 4.8 mm. All patients reported multiple dislocations. Intraoperatively, 71% presented III°-IV° cartilage lesions, located retropatellarly in 87% and correlating negatively with the postoperative Lysholm score (r = - 0.462, p = 0.040). The leg axis was corrected by 7.1° ± 2.6°, and in 17 cases, the tibial tubercle was additionally medialized by 10 ± 3.1 mm. All patellae were re-stabilized with medial patellofemoral ligament reconstruction. After a median period of 16 (12-64) months, the pain level decreased from 8.0 ± 1.4 to 2.3 ± 2.1 (VAS p ≤ 0.001) and knee function improved from 40.1 ± 17.9 to 78.5 ± 16.6 (Kujala p ≤ 0.001), 36.1 ± 19.5 to 81.6 ± 11.7 (Lysholm p ≤ 0.001), and 2.0 (1-5) to 4.0 (3-6) (median Tegner p ≤ 0.001). No re-dislocation was observed.Conclusion: Combined DFO is a suitable treatment for patellar instability and maltracking due to genu valgum, as it leads to very low re-dislocation rates, a significant reduction of pain, and a significant increase of knee function with good-to-excellent results in the short-term follow-up. However, a high prevalence of substantial cartilage lesions is observed, causing postoperative limitations of knee function.Level Of Evidence: IV, retrospective cohort study. [ABSTRACT FROM AUTHOR]

Purpose: Graft tensioning during medial patellofemoral ligament (MPFL) reconstruction typically allows for lateral patellar translation within the trochlear groove. Computational simulation was performed to relate the allowed patellar translation to patellofemoral kinematics and contact pressures.Methods: Multibody dynamic simulation models were developed to represent nine knees with patellar instability. Dual limb squatting was simulated representing the pre-operative condition and simulated MPFL reconstruction. The graft was tensioned to allow 10, 5, and 0 mm of patellar lateral translation at 30° of knee flexion. The patellofemoral contact pressure distribution was quantified using discrete element analysis.Results: For the 5 and 10 mm conditions, patellar lateral shift decreased significantly at 0° and 20°. The 0 mm condition significantly decreased lateral shift for nearly all flexion angles. All graft conditions significantly decreased lateral tilt at 0°, with additional significant decreases for the 5 and 0 mm conditions. The 0 mm condition significantly increased the maximum medial pressure at multiple flexion angles, increasing by 57% at 30°, but did not alter the maximum lateral pressure.Conclusions: Allowing 5 to 10 mm of patellar lateral translation limits lateral maltracking, thereby decreasing the risk of post-operative recurrent instability. Allowing no patellar translation during graft tensioning reduces maltracking further, but can overconstrain the patella, increasing the pressure applied to medial patellar cartilage already fibrillated or eroded from an instability episode. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the stabilizing effect of a lateral meniscus posterior root repair in an ACL and root deficient knee.Methods: The hypothesis of the current study was that a sequential transection of the posterior root and the meniscofemoral ligaments in an ACL-deficient knee increases rotational instability, and conversely, a repair of the meniscus root reduces the internal tibial rotation. Therefore, eight human knee joints were tested in a robotic setup (5 N m internal torque, 50 N m anterior translation load). Five conditions were tested: intact, ACL cut, ACL cut + lateral meniscus posterior root tear (LMRT), ACL cut + LMRT + transection of the MFL and ACL cut + lateral meniscus root repair. The angles of internal tibial rotation as well as anterior tibial translation were recorded.Results: Transection of the lateral meniscus posterior root increased the internal tibial instability as compared to the ACL-insufficient state. A significant increase was detected in 60° and 90° of flextion. Sectioning of the meniscofemoral ligament further destabilized the knees significantly at all flexion angles as compared to the ACL-deficient state. Even in 30°, 60° and 90° a significant difference was detected as compared to the isolated root tear. A tibial fixation of the lateral meniscus root reduced the internal tibial rotation in all flexion angles and led to a significant decrease of internal tibial rotation in 30° and 90° as compared to the transection of the root and the MFL. The anterior tibial translation was increased in all conditions as compared to the native state.Conclusion: A lateral meniscus root repair can reduce internal tibial rotation in the ACL-deficient knee. To check the condition of the lateral posterior meniscus root attachment is clinical relevant as a lateral meniscus root repair might improve rotational stability. [ABSTRACT FROM AUTHOR]

Purpose: In total knee arthroplasty (TKA), the posterior tibial slope is not always reconstructed correctly, and the knee ligaments may become too tight in flexion. To release a tight flexion gap, surgeons can increase the posterior tibial slope using two surgical resection techniques: the anterior tibial cortex (ACR) or the centre of tibial plateau (CPR) referencing. It is not known how this choice affects the knee laxity and function during activities of daily living. The aim of this study was to investigate the effect of tibial slope on knee laxity, kinematics and forces during a squatting activity using computer simulation techniques. We hypothesised that the effects depend on the referencing technique utilised.Methods: A validated musculoskeletal model of TKA was used. Knee laxity tests were simulated in flexion and extension. Then, a squat motion was simulated to calculate: movement of the tibiofemoral joint (TFJ) contact points and patello-femoral joint (PFJ) contact force. All analyses were repeated with more anterior (-3°), neutral (0°), and more posterior tibial slope (+3°, +6°, +9°), and with two referencing techniques (ACR, CPR).Results: Knee laxities increased dramatically with more posterior slope with the ACR technique (up to 400%), both in flexion and in extension. The CPR technique, instead, had much smaller effects (up to 42% variations). During squatting, more slope with the ACR technique resulted in larger movements of the TFJ contact point. The PFJ contact force decreased considerably with more slope with the CPR technique (12% body weight reduction every 3° more posterior slope), thanks to the preservation of the patellar height and quadriceps-femur load sharing.Conclusion: ACR technique alters considerably the knee laxity, both in flexion and extensions, and surgeons should be cautious about its use. More slope with CPR technique induces more favourable TFJ kinematics and loading of the knee extensor apparatus and does not substantially alter knee laxity. Preferably, the tibial slope resection should be pre-planned thoroughly and performed using CPR technique as accurately as possible. Surgeons can directly translate the results of this study into the clinical practice. [ABSTRACT FROM AUTHOR]

Purpose: Medial patellofemoral ligament reconstruction (MPFL-R) is the standard surgical intervention for patella instability. However, limited knowledge exists concerning the causes for failure, and outcome after revision MPFL-R. The purpose of this study is to evaluate the causes of primary MPFL-R failure and clinical outcomes after revision MPFL-R.Methods: Twenty-three patients (6 males and 17 females) with failed primary MPFL-R underwent isolated revision MPFL-R or combined revision MPFL-R with tibial tuberosity osteotomy (TTO). The mean age was 23 (SD 8.6). Prior to surgery, dysplasia of the patellofemoral joint, sulcus angle, Insall-Salvati index, cartilage lesions, tibial tuberosity trochlear groove (TTTG) distance, and tunnel placement were evaluated by magnetic resonance imaging (MRI). Their scores on the Kujala Anterior Knee Pain Scale and pain scores were assessed prior to surgery, 1 year post-operatively and at final follow-up. The mean follow-up time was 44 months (median range 39). The radiographic characteristics and clinical outcomes were compared with a 224 primary MPFL-R patient cohort (240 knees).Results: Non-anatomical fixation of the graft at the medial femoral condyle after primary MPFL-R was seen in 67% of revision patients with anterior/proximal misplacement in most cases. Severe trochlear dysplasia Dejour types C and D were seen in 36% of the patients compared to 30% of primary MPFL-R patients (NS). The mean Kujala Anterior Knee Pain Scale score at final follow-up was 61.7 (SD 18.8) compared to 80.3 (SD 18) in primary MPFL-R patients (P < 0.01). The mean pain score at rest was 2.3 (SD 2.5) for revision MPFL-R patients compared to 1.7 (SD 2.5) in primary MPFL-R patients (NS) and their mean pain score during activity was 5.0 (SD 3.2) compared to 1.3 (SD 2.2) in primary MPFL patients (P < 0.001).Conclusion: Although revision MPFL-R establishes acceptable patellar stability, the subjective outcomes after revision MPFL-R do not improve significantly, and are poorer than after primary MPFL-R. Non-anatomical graft position can be an important cause of MPFL-R failure. The clinical relevance of this study is that it shows that it may be difficult to improve self-reported outcomes in revision MPFL-R patients.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Background: Spinous processes and posterior ligaments, such as inter- and supraspinous ligaments are often sacrificed either deliberately to harvest osseous material for final spondylodesis e.g. in deformity corrective surgery or accidentally after posterior spinal instrumentation. This biomechanical study evaluates the potential destabilizing effect of a progressive dissection of the posterior ligaments (PL) after instrumented spinal fusion as a potential risk factor for proximal junctional kyphosis (PJK).Methods: Twelve calf lumbar spines were instrumented from L3 to L6 (L3 = upper instrumented vertebra, UIV) and randomly assigned to one of the two study groups (dissection vs. control group). The specimens in the dissection group underwent progressive PL dissection, followed by cyclic flexion motion (250 cycles, moment: + 2.5 to + 20.0 Nm) to simulate physical activity and range of motion (ROM) testing of each segment with pure moments of ±15.0 Nm after each dissection step. The segmental ROM in flexion and extension was measured. The control group underwent the same loading and ROM testing protocol, but without PL dissection.Results: In the treatment group, the normalized mean ROM at L2-L3 (direct adjacent segment of interest, UIV/UIV + 1, PJK-level) increased to 104.7%, 107.3%, and 119.4% after dissection of the PL L4-L6, L3-L6, and L2-L6, respectively. In the control group the mean ROM increased only to 103.2%, 106.7%, and 108.7%. The ROM difference at L2-L3 with regard to the last dissection of the PL was statistically significant (P = 0.017) and a PL dissection in the instrumented segments showed a positive trend towards an increased ROM at UIV/UIV + 1.Conclusions: A dissection of the PL at UIV/UIV + 1 leads to a significant increase in ROM at this level which can be considered to be a risk factor for PJK and should be definitely avoided during surgery. However, a dissection of the posterior ligaments within the instrumented segments while preserving the ligaments at UIV/UIV + 1 leads to a slight but not significant increase in ROM in the adjacent cranial segment UIV/UIV + 1 in the used experimental setup. Using this experimental setup we could not confirm our initial hypothesis that the posterior ligaments within a long posterior instrumentation should be preserved. [ABSTRACT FROM AUTHOR]

Background: Although smoking is known to be harmful to the musculoskeletal system, no studies have investigated its effects on the outcomes of ankle ligament surgery. We determined the effects of smoking on the clinical and radiological outcomes of lateral ankle ligament reconstruction using tendon allografts according to smoking status.Methods: From among 105 patients with chronic ankle instability who were treated with anatomical reconstruction of the anterior talofibular ligament and the calcaneofibular ligament using semitendinosus tendon allografts and bio-tenodesis screws, 70 ankles, from 23 smokers and 47 non-smokers, were analyzed. Visual analog scale (VAS) pain scores, American Orthopedic Foot and Ankle Society ankle-hindfoot scores, Karlsson scores and complications were routinely determined at each follow-up visit. Anterior translation and the talar tilt angle on radiographic stress views were also assessed.Results: The mean follow-up period was 21.8 months (12-68 months). No significant differences were observed between the two groups with respect to age, gender, body mass index, or the duration of preoperative symptoms. The mean preoperative pain VAS scores were 5.8 and 5.3 among non-smokers and smokers, respectively. Postoperatively, the mean pain VAS score improved to 1.4 in both groups (p < 0.001). Clinical and radiographic measures did not show significant changes according to the presence of smoking after surgery. However, two wound complications, 1 delayed healing and 1 superficial necrosis, occurred in non-smokers, whereas five, 2 delayed healing, 2 superficial infections and 1 superficial necrosis in smokers (p = 0.035).Conclusion: The radiographic outcomes of smokers were comparable to those of non-smokers in the short term, whereas wound complications were more common in the smoker group. [ABSTRACT FROM AUTHOR]

The anterolateral ligament (ALL) of the knee has gained attention recently for its potential role in rotational stability of the knee, especially in association with anterior cruciate ligament (ACL) injuries. Anatomic studies have characterized the ALL as it runs in an anteroinferior and oblique direction from the lateral distal femur to the anterolateral proximal tibia, although the prevalence and variance of this ligament are not well understood. Magnetic resonance imaging and ultrasound have identified the ligament and linked it with the classically described Segond fracture. While the ALL likely plays a role in rotational stability of the knee, further studies investigating the significance of ALL injuries and the role of ALL reconstruction in combination with ACL reconstruction are warranted. [ABSTRACT FROM AUTHOR]

Purpose: Recurrent patella dislocation (RPD) is the most common complication of patellar instability. The effects of different surgical techniques on the outcome of RPD treatments remain unclear. This study was conducted to compare the effects of three surgical techniques in treating RPD by three-dimensional (3D) reconstruction from computed tomography (CT) scans.Methods: Sixty-eight patients with RPD and no previous surgical treatments who attended our hospital between October 2010 and 2013 were enrolled and randomly assigned into three groups: (1) medial patellofemoral ligament (MPFL) reconstruction and medial patellar retinaculum (MPR) plication group; (2) lateral patellar retinaculum (LPR) release and MPR plication group; and (3) MPFL reconstruction and LPR release group. Knee joints with flexion of 20° were scanned by a 64-row CT scanner and 3D reconstructed. Congruence angle (CA), patellar tilt angle (PTA), lateral patellofemoral angle (LPFA), and congruence of the lateral patellofemoral articular surface were measured. Knee joint function was evaluated by the Lysholm knee scoring scale, Kujala patellofemoral score, and International Knee Documentation Committee (IKDC) score.Results: Pre-operative clinical characteristics were similar across groups. After treatment, the CA, PTA, and LPFA were reverted to normal post-operatively without statistically significant between-group differences. The MPFL reconstruction and LPR release group had the highest congruence of the lateral patellofemoral articular surface; while the (LPR) release and (MPR) plication group had the lowest Lysholm knee scoring scale, Kujala patellofemoral score, and IKDC score after surgery.Conclusions: The MPFL reconstruction and LPR release group had the best clinical outcomes among the three surgical methods, as indicated by better joint congruence after 3D joint reconstruction and higher knee function scores. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the appropriate amount of knee flexion in which to secure the graft during medial patellofemoral ligament (MPFL) reconstruction.Methods: Heavy suture was used to simulate graft tissue during MPFL reconstruction on eight fresh-frozen cadaveric knees. The sutures were passed through two transverse patellar tunnels and draped over a Kirschner wire at Schöttle's point on the femur. Suture displacement at the location of the wire was measured during knee range of motion from 0 to 135°. The wire's location was then moved to 3 additional locations (1 cm proximal, 1 cm distal, and 1 cm anterior), and the measurements were repeated.Results: Using Schöttle's point, the suture length did not vary throughout all ranges of knee flexion. The distal location resulted in a greater distance between attachment points (i.e. graft tightened) if the measurements began with the knee flexed and then brought into extension. Conversely, with the proximal location, the opposite occurred as the knee was extended (i.e. graft loosened). For all locations other than Schöttle's point, the amount of initial knee flexion for fixation was directly related to the amount of suture length change when the knee was brought into extension.Conclusion: For non-anatomic femoral MPFL graft fixation locations, suture length (and thus graft length) in full extension becomes increasingly altered if the graft is secured in high degrees of knee flexion. Thus, graft fixation in lower degrees of knee flexion is recommended to minimize over or under tensioning the graft when the knee goes into extension if the graft position is placed in a non-anatomic location. To avoid this problem, fluoroscopy should be used to locate the anatomic footprint of the MPFL insertion. While recognizing the limitations of cadaveric research, this study is the first to provide any data to corroborate the widely used practice of securing the MPFL in lower degrees of knee flexion. [ABSTRACT FROM AUTHOR]

Purpose: How much force is needed to pre-tension the ligaments during total knee arthroplasty? The goal of this study was to determine this force for extension and flexion, and for both compartments, and to identify predicting patient-related factors.Methods: Eighty patients [55 females, mean age 71 (SD 9.7)] were recruited and had a navigated cruciate-retaining total knee arthroplasty. Distraction of the medial and lateral compartments of the extension and flexion gap (90°) with an instrumented bi-compartmental double-spring tensioner took place after finishing the bone cuts. Applied forces and resulting gap distances were recorded by the navigation system, resulting in a force-elongation curve. Lines were fitted with the intersection defined as the stiffness transition point. The slopes (N/mm) represented the stiffness of the ligamentous complex. Linear multiple regression analysis was performed to identify predicting factors.Results: The amount of force at the stiffness transition point was on average 52.3 (CI95 50.7-53.9), 54.5 (CI95 52.7-56.3), 48.3 (CI95 46.2-50.2), and 59.3 (CI95 57.0-61.6) N for the medial and lateral extension and flexion gap, respectively, and varied considerably between patients. The force at the stiffness transition point was significantly different between extension and flexion and both compartments (P < 0.05). Stiffness of the ligaments statistically significantly helped to predict the amount of force at the stiffness transition point, as well as body mass index, gender, and varus-valgus alignment.Conclusion: The amount of force at the stiffness transition point varies between 48 and 59 N, depending on flexion/extension and compartment. Patient-related factors influence the stiffness transition point and can help predict the stiffness transition point. When forces higher than 60 N are used for gap distraction, the ligamentous sleeve of the knee might be over-tensioned.Level Of Evidence: Prognostic study, Level I-high-quality prospective cohort study with >80 % follow-up, and all patients enrolled at same time point in disease. [ABSTRACT FROM AUTHOR]

Background: The acromioclavicular (AC) joint dislocation is a major reason for shoulder instability. Different concepts of treatment and surgical methods are described in the literature. Thus, the purpose of this study was to present our data of long-term follow-up of patients having undergone treatment of acromioclavicular (AC) joint dislocation using the Bosworth Screw with additional K-wiring.Methods: This study was conducted as a retrospective single centre data analysis. All patients treated operatively for AC joint dislocation with a Bosworth screw and additional K-wire fixation at our Department were asked to participate in this study.Results: The study population consisted of 22 patients, 20 male and 2 female, with a mean age of 40 years ±15.6 years. Three grade-II lesions, 13 grade-III lesions, four grade-IV lesions and two grade-V lesions according to the Rockwood classification were found. The overall mean clinical outcome at the latest follow up was: Constant 95, DASH 6.4, ASES 94.6, SST 99.02, UCLA 33.1, ACJI 91.82 and VAS 0.29 - representing a good-to-excellent long-term outcome in all patients after at least 2 years follow-up (range; 2 - 19 years). Overall, 19 patients (86%) reported to be very satisfied with the achieved result, 15 patients (68%) reported to be able to participate in every sports activity and 16 patients (73%) reported to be able to perform their daily work without limitations. Overall, complications occurred in three patients (14%). Only one patient remained unsatisfied with the achieved result.Conclusion: Summarizing, our reported results showed that surgical fixation of acute AC joint dislocation with a Bosworth screw and additional K-wire fixation leads to good-to-excellent functional outcome and highly satisfactory results in the majority of patients. Despite its complications, in accordance with our results, Bosworth screw fixation with additional K-wiring in AC joint dislocation represents an adequate surgical procedure.Level Of Evidence: Level IV, retrospective study. [ABSTRACT FROM AUTHOR]

Purpose: Medial patellofemoral ligament (MPFL) reconstruction has become a common form of treatment for recurrent patellar dislocation. This study was performed using open-MRI to compare the length change pattern of MPFL in patients with a history of patellar dislocation to that in healthy subjects.Methods: The subjects comprised 10 knees of 8 males and 13 knees of 12 females with a history of one or more patellar dislocations. The length of the MPFL was measured using open-MRI in both the leg-extended position and knee-flexed positions to analyse the length change pattern.Results: The average MPFL lengths were 58.6 ± 6.5 mm and 52.0 ± 4.6 mm for males and females in the extended knee position, respectively. The length change pattern of the MPFL showed slight variation up to a flexion angle of 30° and a clear decrease above 30°. This pattern differed from that of normal MPFL. In terms of morphology, the fibre bundle of the damaged MPFL followed a convex course towards the side of the patellofemoral joint surface at a knee flexion angle of 60°, whereas that of the normal MPFL followed a straight course.Conclusion: The in vivo damaged MPFL length change pattern was specific and differed distinctly from that of normal MPFL. The results of the present study suggested that MPFL fibres with a history of patellar dislocation lack sufficient tension at knee flexion angles of 0°-60°. However, further studies are needed to obtain a better understanding of cases with a patellar dislocation or postsurgical cases of MPFL reconstruction.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: This study's purpose was to investigate how an ideal anatomic femoral attachment affects the dynamic length change pattern of a virtual medial patellofemoral ligament (MPFL) from an extended to a highly flexed knee position; to determine the relative length and length change pattern of a surgically reconstructed MPFL; and to correlate femoral attachment positioning, length change pattern, and relative graft length with the clinical outcome.Methods: Twenty-four knees with isolated nonanatomic MPFL reconstruction were analysed by three-dimensional computed tomography at 0°, 30°, 60°, 90°, and 120° of knee flexion. The lengths of the MPFL graft and a virtual anatomic MPFL were measured. The pattern of length change was considered isometric if the length distance changed <5 mm through the entire dynamic range of motion.Results: Knee flexion significantly affected the path lengths between the femoral and patellar attachments. The length of the anatomic virtual MPFL decreased significantly from 60° to 120°. Its maximal length was 56.4 ± 6.8 mm at 30°. It was isometric between 0° and 60°. The length of the nonanatomic MPFL with a satisfactory clinical result decreased during flexion from 0° to 120°. Its maximal length was 51.6 ± 4.6 mm at 0° of knee flexion. The lengths measured at 0° and 30° were isometric and statistically greater than the lengths measured at higher flexion degrees. The failed nonanatomic MPFL reconstructions were isometric throughout the dynamic range, being significantly shorter (27.1 ± 13.3 %) than anatomic ligaments.Conclusion: The femoral attachment point significantly influences the relative length and the dynamic length change of the grafts during knee flexion-extension and graft isometry. Moreover, it influences the long-term outcome of the MPFL reconstructive surgery. A nonanatomic femoral fixation point should not be considered the cause of persistent pain and instability after MPFL reconstruction in all cases.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: Malpositioning of the femoral entry point in reconstruction of the medial patellofemoral ligament (MPFL) can lead to abnormal and painful patellar kinematics and loss of flexion. Determination of this point is usually performed by palpation of anatomic landmarks. Accuracy of this method has not yet been investigated. The hypotheses were: 1. palpatory method is not as accurate as fluoroscopically guided method using established radiological criteria; 2. accuracy correlates with surgical experience.Methods: Three surgeons of varying experience defined the femoral entry point for the MPFL by palpation in ten cadaveric legs. The blinded procedures were repeated three times, and subjective difficulty of the determination was recorded. Results were documented by fluoroscopy on a true lateral radiograph. The accuracy was assessed using established radiological criteria. Surgical experience was correlated with the results, and confounding or interacting variables were assessed.Results: Mean deviation from the correct zone for the femoral entry point was 3.5 mm (range 0-18 mm). Twenty-nine percent of all palpatory determinations were inside the correct zone, 47 % were within 5 mm distance from the correct zone, and 23 % were further than 5 mm apart from the correct zone ("outliers"). No significant difference was found between surgeons of varying experience. No correlation was observed between subjective difficulty of the procedure and accuracy of determination.Conclusions: The validity of the isolated palpatory determination of the femoral entry point in MPFL reconstruction seems to be insufficient, regardless of surgical experience. Derived from this study, fluoroscopic guidance is used in our clinic by default. [ABSTRACT FROM AUTHOR]

Background: Rotational instability of the knee remains an issue after anterior cruciate ligament (ACL) reconstruction. Hypothesis/Purpose: The purpose was to evaluate the subjective and objective outcomes of combined reconstruction of the ACL and anterolateral ligament (ALL) of the knee. The hypothesis was that favorable outcomes can be achieved with this surgical procedure compared with isolated anatomic reconstruction of the ACL. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: One hundred ten patients with a unilateral ACL injury and high-grade pivot shift were randomly assigned to undergo either combined ACL and ALL reconstruction (group A) or isolated ACL reconstruction (group B). Preoperative and postoperative evaluations of the patients were conducted by obtaining history details, recording physical examination findings, measuring knee laxity using the KT-1000 arthrometer, and using validated outcome scores for the knee. P < .05 was considered as the cut-off level of statistical significance. The Fisher exact and Mann-Whitney U tests were used to assess statistical significance. Results: At a mean follow-up of 27 months, 53 and 50 patients in groups A and B, respectively, were available for analysis. No statistically different outcomes were found between the 2 groups except for the KT-1000 arthrometer values. The median KT-1000 arthrometer result for combined ACL and ALL reconstruction was 1.3 mm, while the median result for isolated ACL reconstruction was 1.8 mm (P < .001). None of the patients (n = 0; 0.0%) who underwent combined ACL and ALL reconstruction had anterior translation of greater than 5 mm at maximum pulling strength compared with their normal knees at final follow-up. On the other hand, 3 (6.0%) patients who underwent isolated ACL reconstruction had anterior translation of more than 5 mm. No serious complications were found in both groups. Conclusion: Combined ACL and ALL reconstruction was found to be effective in improving subjective and objective outcomes. Nevertheless, these findings were not significantly superior to isolated ACL reconstruction except for the instrumented knee laxity testing results. This might indicate that ALL reconstruction should not be performed routinely for patients undergoing ACL reconstruction. [ABSTRACT FROM AUTHOR]

Purpose: Rising expectations in functional performance of total knee joints are inciting further improvement of knee arthroplasty implants. From a patient-centred view, bicruciate-retaining models provide a more natural feeling knee. However, there is no evidence of functional advantage for these implants. The aim of this study was to evaluate balance ability as a measure of proprioception in patients with a bicruciate-retaining total knee arthroplasty.Methods: A prospective, controlled trial was conducted to compare balance ability in 60 patients after arthroplasty of the knee for osteoarthritis. We compared patients with a bicruciate-retaining knee arthroplasty (BCR group) to a control group of patients with a medial unicompartmental knee arthroplasty (UKA group) and another control group of patients with a posterior stabilized total knee arthroplasty (PS group). The patient population comprised 30 women (50.0 %) and 30 men in three cohorts of 20 each. The mean age was 62.1 ± 8.0 years (range 43-78). Patients were evaluated preoperatively and 9 months post-operatively. The evaluation included clinical, radiological, and balance testing-a single-leg stance with eyes closed compared to eyes open. The difference in area of sway between eyes closed and eyes open represents static balance ability after knee arthroplasty.Results: Perioperative data showed that there was no intra-operative fracture of the intercondylar eminence. There was a decreased post-operative knee extension 9 months post-operative in the BCR group, which was not clinically relevant in any case. We recorded a lower difference in the area of sway between eyes closed and eyes open (ΔA (ec-eo)) for the BCR group (p = 0.01) and the UKA group (p = 0.04) compared to the PS group.Conclusions: This study found superior static balance ability after preservation of both cruciate ligaments in arthroplasty of the knee, indicating superior proprioceptive function. Hence, BCR implants could provide improved functional properties. Superior proprioceptive function of bicruciate-retaining implants can be an important factor in implant selection. Further prospective, randomized studies to investigate kinematics and long-term survivorship of bicruciate-retaining implants are needed.Level Of Evidence: II. [ABSTRACT FROM AUTHOR]

Purpose: To date, there is a paucity of literature on syndesmotic reconstruction techniques that restore both anatomic stability and physiologic syndesmotic biomechanics. In this cadaveric study, (1) a novel syndesmotic reconstruction surgical technique using autogenous peroneus brevis tendon was described and (2) the biomechanical properties of the reconstruction was investigated.Methods: Ten fresh-frozen lower extremities were used in this study. Reconstruction of the anterior and posterior, as well as the interosseous tibiofibular ligaments was performed with a halved peroneus brevis tendon. Biomechanics were assessed using foot external rotation torque and ankle dorsiflexion axial loading tests, which were performed in (a) intact, (b) cut, (c) anatomically reconstructed syndesmotic ligaments, and (d) 3.5 mm tricortical syndesmotic screw fixation. Medial-lateral and anterior-posterior displacements of the distal fibula were recorded during foot external rotation and fibular axial displacement was recorded during ankle axial loading.Results: The fibula was displaced posteriorly and proximally with respect to the tibia in all specimens during external rotation and axial loading tests, respectively. Significant differences (p < 0.05) were found in distal fibular displacements between anatomically reconstructed ligaments and screw fixation. Tricortical syndesmotic screw fixation resulted in 59% of posterior fibular displacement when compared to intact ligaments. No significant differences (n.s.) in distal fibular displacement were demonstrated between intact ligaments and anatomically reconstructed ligaments.Conclusion: Anatomical reconstruction of the distal tibiofibular ligaments with the peroneus brevis tendon provides stability and recreates the biomechanical properties of an intact syndesmosis. This new surgical technique may be a viable alternative for the treatment of syndesmotic injuries.Level Of Evidence: V. [ABSTRACT FROM AUTHOR]

Purpose: The biomechanical behaviour of the knee following multiple-ligament reconstruction (MLKR) may play a role in the pathogenesis of post-traumatic osteoarthritis. The aim of this study was to compare three-dimensional knee kinematics and gait characteristics of MLKR patients to healthy controls during level walking.Methods: Three-dimensional optoelectronic motion capture during overground walking was performed on 16 patients with MLKR and a group of healthy controls matched individually to each patient for age, gender, height and weight. Three-dimensional knee angles were extracted from the weight acceptance and propulsion sub-phases of gait. Statistical analysis was performed using group-aggregated data, as well as for each patient-control pair using a single-case approach.Results: Although group analysis detected few differences, single-case analysis revealed significant differences for a proportion of patients for all dependent variables during weight acceptance and propulsion sub-phases of stance. These kinematic differences occurred in the context of reduced gait velocity, step length and cadence, as well as increased time spent in double support.Conclusion: Patients with MLKR display abnormalities in knee kinematics during gait at an average of 4.5 years after surgery. The pattern of kinematic abnormalities appears individual specific and may not be related to differences in spatiotemporal gait characteristics. The current findings describe detailed functional outcomes of MLKR reconstruction at average medium-term follow-up that provide improved prognostic information for clinicians to counsel patients with these types of injuries. [ABSTRACT FROM AUTHOR]

Purpose: The anterolateral ligament (ALL) has been proposed as a possible extra-articular stabiliser of the knee. Injury to the ALL may result in residual instability following surgical reconstruction of a ruptured anterior cruciate ligament (ACL). Few studies have evaluated the biomechanical role of the ALL. The purpose of this study was to investigate whether sectioning the ALL would have an influence on tibiofemoral translation or rotation during the anterior drawer, Lachman, pivot shift, external rotation, and internal rotation tests in an ACL-deficient knee.Methods: Only whole-body specimens having an ALL were included in this study. Lachman, anterior drawer, external rotation, and internal rotation tests were performed manually. Pivot shift test was done using a mechanised pivot shifter. The amount of tibiofemoral translation and rotation was recorded by a navigation system. Each specimen was tested in its native state, after sectioning the ACL, and after combined sectioning of the ACL and the ALL.Results: In six out of 14 cadaveric knees, an ALL could be identified. The ACL-deficient knee had significantly more tibiofemoral translation and rotation compared to the native knee (P < 0.05). However, no changes in the magnitudes of translation or rotation were seen after subsequent sectioning of the ALL compared to the ACL-deficient knee (P > 0.05).Conclusion: Adding an ALL lesion in an ACL-deficient knee did not increase tibiofemoral instability in this cadaveric model. It remains unclear whether injury to the ALL would result in substantial knee instability in the setting of ACL injury in vivo. Further research is warranted to fully elucidate the role of the ALL during knee kinematics and to determine in which scenarios ALL repair would be warranted. Understanding the function of the ALL may improve the current treatment strategies for ACL ruptures. [ABSTRACT FROM AUTHOR]

Purpose: To quantify the influence of Single-Bundle with Lateral Plasty and Double-Bundle reconstruction on static and dynamic laxity in combined ACL- and ALL-deficient knees.Methods: The study included 10 fresh-frozen human knees. The joints were analyzed in the following conditions: ACL + ALL resection, Single-Bundle with Lateral Plasty (SBLP) reconstruction, Double-Bundle (DB) reconstruction. Testing parameters were: anterior displacement at 30° and 90° of flexion (AP30, AP90) applying a manual maximum load; internal rotation at 30° and 90° of flexion (INT30, INT90) applying a 5 Nm torque and acceleration and internal rotation Pivot-Shift (PS) test. Kinematics was acquired by a navigation system. Paired Student's t test was conducted to assess statistical difference (P < 0.05).Results: At both 30° and 90° of knee flexion, both SBLP and DB surgical techniques showed a significant reduction (P < 0.01) of anterior-posterior tibial displacement compared to the resection of ACL + ALL. At 30° on knee flexion it is the SBLP that allows the greatest reduction of internal rotational laxity when compared to DB reconstruction. Concerning the PS test, only SBPL procedure had a significant laxity decrease considering the acceleration reached by the joint when compared with the ACL + ALL state (P < 0.01).Conclusion: Clinical relevance of this study is that the internal rotation and PS test were more efficiently controlled by the SBLP technique than by the DB one at both 30° and 90° of flexion in case of ACL + ALL lesions. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the separate contribution of the two definitions of the anterolateral ligament (ALL), the mid-third lateral capsular ligament (MTLCL) and deep capsule-osseous layer of the iliotibial tract (dcITT) in addition to the superficial iliotibial tract (sITT) to the control of tibial motion with respect to the femur during the application of force/torque seen during the three tests of the standard clinical knee examination (AP Lachman test, tibial axial rotation test and varus-valgus stress test).Methods: Six pelvis-to-toe cadaveric specimens were examined using an automated testing device that carried out the three components of the clinical knee examination. Internal/external rotation torque, anteroposterior load and adduction/abduction torque were applied, while torque/force and positional measurements were recorded. Sequential sectioning of the structures followed the same order for each knee, sITT, dcITT and MTLCL. Testing was repeated after release of each structure.Results: During the tibial axial rotation test, releasing the sITT caused an increase in internal rotation of 2.6° (1.4-4.1°, p < 0.0005), while release of the dcITT increased internal rotation an additional 0.8° (0.4-1.1°, p < 0.0015). Changes in secondary motions of the tibia after sITT release demonstrated an increase in anterior translation of 1.2 mm (0.6-2.0 mm, p < 0.0005) during internal rotation, while release of the dcITT increased the same motion an additional 0.4 mm (0.2-0.5 mm, p < 0.0005). During the AP Lachman test, release of the sITT caused the tibia to move more anteriorly by 0.7 mm (0.4-1.1 mm, p < 0.0005) and increased internal rotation by 2.7° (0.9-5.2°, p < 0.004). The additional release of the dcITT resulted in more anterior translation by 0.3 mm (0.1-0.4 mm, p < 0.002) and internal rotation by 0.9° (0.2-1.7°, p < 0.005). During the varus-valgus stress test, release of the sITT permitted 0.9° (0.4-1.4°, p < 0.0005) more adduction of the tibia, while the additional release of the dcITT significantly increased adduction by 0.4° (0.2°-0.5°, p < 0.001). Release of the MTLCL had a nominal but significant increase in internal rotation, 0.6° (0.1-1.1°, p < 0.0068) and external rotation, -0.1° (-0.1° to -0.2°, p < 0.0025) during the tibial axial rotation test, anterior translation of 0.2 mm (0.0-0.4 mm, p < 0.021) only during the AP Lachman test, and adduction rotation, 0.2° (0.0-0.3°, p < 0.034) only during the varus-valgus stress test.Conclusion: The presence of increased adduction during an automated knee examination provides unique information identifying the release of the sITT, dcITT and the MTLCL in this cadaveric study. While their sequential release caused similar pattern changes in the three components of the automated knee examination, the extent of change due to release of the MTLCL was markedly less than after release of the dcITT which was markedly less than after release of the sITT. [ABSTRACT FROM AUTHOR]

Background: Recurrent patellar dislocation is common clinically, primarily in adolescents. However, the biomechanical properties of single- and double-bundle medial patellofemoral ligament (MPFL) reconstruction remain poorly understood. Methods: Six fresh frozen adult cadaveric knee specimens were obtained for this study. Each specimen was fixed at 0° to test the force needed when the patella was laterally shifted 10 mm at a speed of 0.5 mm/s, and the test was repeated three times. This test was repeated when knee flexion was at 0°, 15°, 30°, 45°, 60°, and 90°. All six specimens were tested in four statuses, including MPFL intact, MPFL torn, single-bundle MPFL reconstruction, and double-bundle MPFL reconstruction. Results: Similar force is required in these MPFL statuses at 0° of flexion, except for the MPFL torn group with a smaller force (45.5 ± 9.6 N, < 0.05). The force required in the MPFL torn group reduced from 12.8 to 38.8% compared to other p groups, at 0°, 15°, 30°, and 45° of flexion angles. At the flexion of 15°, the double-bundle reconstruction group required a statistically greater force (85.9 ± 10.1 N) compared to the single-bundle reconstruction group (74.0 ± 7.9 N). Interestingly, no statistical difference was found at flexions of 60° and 90° in these four groups. Conclusions: Both single-bundle and double-bundle MPFL reconstruction can restore the stability of the patella. The double-bundle reconstruction has an angular synergy effect that simulates the MPFL wide footprint in the patella, which enables it to have greater capacity to resist patellar dislocation before the patella entering the femoral trochlea at a smaller flexion angle. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the outcome of a minimally invasive surgical technique for the treatment of patients with acromioclavicular joint dislocation.Methods: Sixteen patients with complete acromioclavicular joint dislocation were enrolled in this study. All patients were asked to follow the less active rehabilitation protocol post-operatively. Computed tomography with 3-D reconstruction of the injured shoulder was performed on each patient post operatively for the assessment of the accuracy of the suture anchor placement in the coracoid process and the reduction of the acromioclavicular joint. Radiographs of Zanca view and axillary view of both shoulders were taken for evaluating the maintenance of the acromioclavicular joint reduction at each follow-up visit. The Constant shoulder score was used for function assessment at the final follow-up.Results: Twenty seven of the 32 anchors implanted in the coracoid process met the criteria of good position. One patient developed complete loss of reduction and another had partial loss of reduction in the anteroposterior plane. For the other 14 patients, the mean Constant score was 90 (range, 82-95). For the patients with partial and complete loss of reduction, the Constant score were 92 and 76 respectively. All of them got nearly normal range of motion of the shoulders and restored to pre-operative life and works.Conclusion: With this minimally invasive approach and limited exposure of the coracoid, a surgeon can place the suture anchors at the anatomical insertions of the coracoclavicular ligament and allow the dislocated joint reduced and maintained well.Level Of Evidence: Level IV, Case series; therapeutic study. [ABSTRACT FROM AUTHOR]

Background: There has been a trend to reconstruct the coracoclavicular (CC) ligaments anatomically for management of acromioclavicular (AC) joint dislocations.Purpose: The aim of this study was to determine the location and orientation of the CC ligaments for anatomic reconstruction of the AC joint.Methods: The subjects were a total of 40 shoulders from 20 Chinese cadavers. Two K-wires were drilled through the insertion center of the conoid and trapezoid ligaments respectively. The distance from the center of the CC ligaments to the bone landmarks of the clavicle and the oblique angle of the two K-wires was measured respectively.Results: The distance from the center of the trapezoid ligament to the lateral end and the anterior border of the clavicle was 21.7 ± 1.1 mm and 6.4 ± 0.5 mm, respectively. The valgus angle and retroversion angle of the trapezoid ligament was 39.3°±0.9° and 6.0°±0.6°, respectively. The distance from the center of the conoid ligament to the lateral end and the posterior border of the clavicle was 36.6 ± 0.9 mm and 5.5 ± 0.4 mm, respectively. The valgus angle and retroversion angle of the conoid ligament was 6.6°±0.7° and 11.0°±0.9°, respectively.Conclusions: These findings are important for the anatomic reconstruction of the AC joint dislocations, by predicting the location and orientation of the conoid and trapezoid ligaments accurately. [ABSTRACT FROM AUTHOR]

Background The location of patellar and femoral fixation of the graft in medial patellofemoral ligament reconstructions has been widely discussed. This study aimed to assess the distances between different patellar and femoral fixation points to identify the least anisometric pairs of points. Methods Ten cadaver knees were attached to an apparatus that simulated an active range of motion of 120°, with three metallic markers fixed onto the medial side of the patella, and seven markings onto the medial epicondyle. The examined points included the proximal patella pole (1), the patellar center (3), the midpoint between points 1 and 3 (2), a point directly on the epicondyle (6), points 5 mm anterior (5) and posterior (7) to the epicondyle, points 5 mm anterior to point 5 (4) and 5 mm posterior to point 7 (8), and points 5 mm proximal (9) and distal (10) to the epicondyle. The distances between patella and femur points were measured by a photogrammetry system at 15° intervals. Findings The pair of points that exhibited the lowest average variability in distance, and hence was the most isometric, was the patella center combined with the anterior to the medial femoral epicondyle. The pairs of points that exhibited the highest average variability in distance, and hence were the least isometric, were the ones located distal or posterior to the medial femoral epicondyle, with less influence by the patellar location. Interpretation Surgeons should avoid positioning the graft distally or posterior to the epicondyle due to the increase in anisometry. [ABSTRACT FROM AUTHOR]

Purpose: There are various types of intertrochanteric fractures that are unstable pertrochanteric fractures of the hip. The aim of this study was to develop a systematic and comprehensive classification of intertrochanteric fractures.Materials and Methods: This study enrolled 74 patients with intertrochanteric fractures treated by us between 2012 and 2015. The fractures were classified using 3D-CT images taken immediately after the fractures occurred based on the course of the lateral fracture line (LFL) that extends through the lateral femoral cortex distal to the vastus ridge of the greater trochanter in the intertrochanteric area. Furthermore, the presence or absence of additional typical fractures was also studied. Then, 4 orthopedic specialists examined the 3D-CT images of 20 patients randomly selected from the 74 patients to evaluate both the inter-rater and intra-rater agreement levels.Results: Intertrochanteric fractures were classified into three types according to the LFL patterns. Type I (41.9%), the Lateral Wall Pattern, has a LFL that extends towards the lateral fiber bundle attachment area of the iliofemoral ligament. Type II (24.3%), the Transverse Pattern, has a LFL that extends towards the medial bundle attachment area. Type III (33.8%), the Reverse Oblique Pattern, has a LFL that extends between the lateral and medial fiber bundle area of the iliofemoral ligament. Each type showed characteristic displacement and was associated with various combinations of typical fractures (fracture across the intertrochanteric line, posteromedial fragment, including the lesser trochanter, posterolateral fragment posterior to the femoral greater trochanter, and banana-shaped big fragment, including both the greater trochanter and the lesser trochanter). The mean κ values for the interobserver and intraobserver agreement levels were 0.77 (0.70-0.85) and 0.76 (0.70-0.85), respectively, which were considered substantial agreement levels.Conclusion: We believe our new classification is a useful communication tool for medical professionals in the diagnosis of fractures. [ABSTRACT FROM AUTHOR]

Purpose: Individual implant alignment in total knee arthroplasty (TKA) has seen growing interest over the past years. This study therefore aimed to develop a surgical technique for implant alignment based on native ligament tension, and to present the results obtained using this technique.Methods: 25 patients were included in this prospective study. Patient-specific instrumentation (PSI) was used for the resection of the extension gap. Ligament tension was measured after the removal of all accessible osteophytes. In the event of asymmetry, the distal femur resection was adjusted up to 2.5° using an adjustable cutting block. The aim was to achieve a symmetrical extension gap without release, not a neutral leg axis. Femoral rotation was aligned on the basis of ligament tension. Patients were followed up to 3 months postoperatively.Results: The postoperative whole-leg axis was 2.8° ± 1.6° varus. Patients achieved a flexion of 118° ± 9°, a Knee Score of 91.5 ± 3.2 and a Function Score of 86.8 ± 8.3 points.Conclusion: For the first time, the new surgical technique described here permits a ligament tension based femoral implant alignment together with PSI. It was shown to be safe, with encouraging clinical and radiological results.Level Of Evidence: Therapeutic study level IV. [ABSTRACT FROM AUTHOR]

Purpose: Recently, tape augmentation for Broström repair has been introduced in order to improve the primary stability of the reconstructed anterior talofibular ligament (ATFL). The biomechanical effect of tape augmentation suture anchor (SA) repair is not known yet. The aim of the present study was to compare construct stability of the traditional Broström (TB) repair compared with a stand alone SA repair (SutureTak, Arthrex) and SA repair combined with tape augmentation (InternalBrace, Arthrex) internal brace (IB) of the ATFL.Methods: Eighteen fresh-frozen human anatomic lower leg specimens were randomly assigned to three different groups: TB group, SA group, and IB augmentation group. In vivo torsion conditions in ankle sprain were carried out quasi-statically (0.5°/s). Torque (Nm) required to resist as well as the rotary displacement (°) of the load frame was recorded. Intergroup differences for age, bone mineral density (BMD), angle at failure, and torque at failure were analysed using ANOVA.Results: In the TB group, ATFL reconstruction failed at an angle of 24.1°, in the SA group failure occurred at 35.5°, and in the IB group it failed at 46.9° (p = 0.02). Torque at failure reached 5.7 Nm for the TB repair, 8.0 Nm for the SA repair, and 11.2 Nm for the IB group (p = 0.04). There was no correlation between angle at ATFL failure, torque at failure, and BMD for the SA or IB groups.Conclusion: The present biomechanical study reveals statistically superior performance in terms of angle at failure as well as failure torque for the IB group compared to the other reconstruction methods. BMD did not influence the construct stability in the SA repair groups. [ABSTRACT FROM AUTHOR]

Background: Recent biomechanical studies have demonstrated that an extra-articular lateral knee structure, most recently referred to as the anterolateral ligament (ALL), contributes to overall rotational stability of the knee. However, the effect of anatomic ALL reconstruction (ALLR) in the setting of anterior cruciate ligament (ACL) reconstruction (ACLR) has not been biomechanically investigated or validated. Purpose/Hypothesis: The purpose of this study was to investigate the biomechanical function of anatomic ALLR in the setting of a combined ACL and ALL injury. More specifically, this investigation focused on the effect of ALLR on resultant rotatory stability when performed in combination with concomitant ACLR. It was hypothesized that ALLR would significantly reduce internal rotation and axial plane translation laxity during a simulated pivot-shift test compared with isolated ACLR. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen cadaveric knees were evaluated with a 6 degrees of freedom robotic system. Knee kinematics were evaluated with simulated clinical examinations including a simulated pivot-shift test consisting of coupled 10-N·m valgus and 5-N·m internal rotation torques, a 5-N·m internal rotation torque, and an 88-N anterior tibial load. Kinematic differences between ACLR with an intact ALL, ACLR with ALLR, and ACLR with a deficient ALL were compared with the intact state. Single-bundle ACLR tunnels and ALLR tunnels were placed anatomically according to previous quantitative anatomic attachment descriptions. Results: Combined anatomic ALLR and ACLR significantly improved the rotatory stability of the knee compared with isolated ACLR in the face of a concurrent ALL deficiency. During a simulated pivot-shift test, ALLR significantly reduced internal rotation and axial plane tibial translation when compared with ACLR with an ALL deficiency. Isolated ACLR for the treatment of a combined ACL and ALL injury was not able to restore stability of the knee, resulting in a significant increase in residual internal rotation laxity. ALLR did not affect anterior tibial translation; no significant differences were observed between the varying ALL conditions with ACLR except between ACLR with an intact ALL and ACLR with a deficient ALL at 0° of flexion. Conclusion: In the face of a combined ACL and ALL deficiency, concurrent ACLR and ALLR significantly improved the rotatory stability of the knee compared with solely reconstructing the ACL. Clinical Relevance: Significant increases in residual internal rotation and laxity during the pivot-shift test may exist in both acute and chronic settings of an ACL deficiency and in patients treated with isolated ACLR for a combined ACL and ALL deficiency. For this subset of patients, surgical treatment of the ALL, in addition to ACLR, should be considered to restore knee stability. [ABSTRACT FROM AUTHOR]

Background Context: In contrast to the majority of outcome data, many consider C1 fractures to be benign injuries and so have advocated for conservative management, except in the case of concomitant transverse atlantal ligament (TAL) injury where C1-C2 or occiput-C2 fusions are recommended. Purpose: Our goal was to evaluate a series of unstable C1 fractures treated with C1 open reduction and internal fixation (ORIF) to assess clinical and radiographic outcomes by determining the success of reduction and pain relief. Study Design/setting: This is a retrospective cohort review. Patient Sample: The sample includes adult patients with unstable C1 fractures treated with open reduction and primary internal fixation. Outcome Measures: Primary outcome measures included visual analog pain scale (VAS), radiographic reduction (lateral mass displacement), maintenance of reduction, C1-C2 instability, and complications. Methods: A retrospective review of all patients with C1 fractures between September 2002 and September 2013 identified 12 consecutive patients from a level I trauma center who were treated with primary internal fixation without fusion. Electronic medical records and preoperative and postoperative radiographs were reviewed. The surgical technique consisted of a posterior cervical approach to the C1 arch and open reduction using bilateral C1 lateral mass screws connected transversely with a rod. Pre- and postoperative computed tomography scans were used to assess reduction. Long-term follow-up flexion and extension radiographs were used to assess C1-C2 stability. The authors did not receive relevant funding in relation to this research. Results: Twelve patients underwent C1 ORIF, with a mean age of 43 (9 males and 3 females) and a mean follow-up of 17 months. Transverse atlantal ligament was found to be disrupted with type I or type II injury in 11 of the 12 patients: 5 type I and 6 type II. Preoperative lateral mass displacement averaged 7.1 mm, with postoperative displacement after reduction averaging 2.4 mm (p-value <.001). The VAS score averaged 0.7 at latest follow-up. No patients went on to develop C1-C2 instability on final flexion-extension films. No patients had a complication that resulted in neurologic deficit or vascular injury associated with the procedure. No patients were found to have late sequelae of malunion or loss of reduction. Two surgically related complications occurred, namely one patient with errant screw requiring return to the operating room (OR) and one with arthrosis of the occipital-C1 joint. Conclusions: Although a small series, early evidence suggests that patients with unstable C1 ring fractures can be successfully managed with primary ORIF. Open reduction and internal fixation results in a stable construct that maintains reduction, results in excellent pain control, and does not lead to C1-C2 instability. In our series, we have not observed the presence of TAL injury to adversely affect outcomes, and thus do not believe it is a contraindication to ORIF. Comparative studies comparing internal fixation with non-operative, C1-C2, or occiput-C2 fusions would yield more insight into optimal treatment options for these fractures. [ABSTRACT FROM AUTHOR]

Objective: The posterolateral (PL) tibial plateau quadrant is laterally covered by the fibular head and posteriorly covered by a mass of muscle ligament and important neurovascular structures. There are several limitations in exposing and fixing the PL tibial plateau fractures using a posterior approach. The aim of this study is to present a novel anterolateral supra-fibular-head approach for plating PL tibial plateau fractures.Methods: Five fresh and ten preserved knee specimens were dissected to measure the following parameters:1) the vertical distance from the apex of the fibular head to the lateral plateau surface, 2) the transverse distance between the PL platform and fibula collateral ligament (FCL), and 3) the tension of the FCL in different knee flexion positions. Clinically, isolated PL quadrant tibial plateau fractures were treated via an anterolateral supra-fibular-head approach and lateral rafting plate fixation. The outcome of the patients was assessed after a short to medium follow-up period.Results: The distance from the apex of the fibular head to the lateral condylar surface was 12.2 ± 1.6 mm on average. With the knee extended and the FCL tensioned, the transverse distance between the PL platform and the FCL was 6.7 ± 1.1 mm. With the knee flexed to 60° and the FCL was in the most relaxed position, the distance increased to 21.1 ± 3.0 mm. Clinically, a series of 7 cases of PL tibial plateau fractures were treated via this anterolateral supra-fibular-head approach. The patient was placed in a lateral decubitus position with the knee flexed to approximately 60 degrees. After the posterior retraction of the FCL, the plate was placed more posteriorly to provide a raft or horizontal belt fixation of the PL tibial plateau fragment. After an average of 14.3 months of follow up, the knee range of motion(ROM) was 121.4° ± 8.8° (range: 105°-135°), the HSS score was 96.7 ± 2.6 (range: 90-100), and the SMFA dysfunction score was 22.4 ± 3.8 (range: 16-28) points.Conclusion: The anterolateral supra-fibular-head approach can provide direct visualization of the posterolateral tibial plateau quadrant and put the plate more posteriorly to provide a raft for the fragments such that good clinical outcomes can be anticipated. [ABSTRACT FROM AUTHOR]

Background: Multiple-ligament injured knee (MLIK) is a rare but severe injury. Although the principles of MLIK management have progressed over the past 40 years, there is a paucity of high-quality evidence upon which to base the management of MLIK. Treatment strategies for MLIK are challenging for most orthopedic surgeons, and the optimal treatment remains controversial, especially with regard to repair vs. reconstruction of the ligaments. The aim of the present study was to observe clinical outcomes of single-stage in situ suture repair of knee dislocation with multiple-ligament injury using nonabsorbable suture material.Methods: Consecutive patients with MLIK between 2002 and 2010 were included, for a total of 25 patients with knee dislocation. 17 patients (18 knees) with closed knee dislocation with a mean follow-up of 4.8 ± 1.3 years were retrospective analyzed. All patients were treated surgically with single-stage in situ suture repair for all injured ligaments and followed a standardized postoperative rehabilitation protocol. The VAS score, satisfactory score, total SF-36 score, Lysholm score, Tegner score, the Meyers functional rating and the ranges of motion and knee stability were used to evaluate outcomes.Results: At final follow-up, mean visual analog scale score was 2.4 ± 0.9, patient satisfaction score was 8.0 ± 1.1, 36-item Short-Form Health Survey total score was 85.5 ± 10.4, and mean Lysholm score was 87.5 ± 7.7. There were significant differences between mean preinjury and postoperative Tegner activity scores (5.6 ± 1.4 and 3.4 ± 1.7, respectively; P < 0.01) and in mean range of motion between the injured and contralateral knees (112.5 ± 8.4° and 129.6 ± 10.3°, respectively; P < 0.01). At final follow-up, no patient demonstrated obvious ligamentous laxity, and only one patient was unable to return to work. Three patients had knee joint stiffness, two had wound problems (infection or fat liquefaction), and two had heterotopic bone formation.Conclusions: Single-stage in situ suture repair of injured ligaments confers advantages of reliable fixation and early exercise. It could be considered as an alternate and effective option in the dislocation knee with multiple-ligament injury. [ABSTRACT FROM AUTHOR]

Recent advances in our understanding of the function of the hip capsule have clarified its importance to normal hip function and kinematics. The iliofemoral ligament is the primary stabilizing structure for controlling anterior translation and external rotation of the hip, and is violated by the arthroscopic interportal capsulotomy. Microinstability of the hip occurring after surgical trauma remains a poorly defined clinical entity. In certain at-risk populations, capsular repair should be considered as part of an arthroscopic hip procedure to achieve optimal outcomes and avoid iatrogenic instability (dislocation or microinstability). Despite a lack of conclusive evidence-based indications, we recommend capsular repair in the settings of borderline hip dysplasia (or dysplastic variants such as increased femoral anteversion), hip hypermobility, connective tissue disorders, and traumatic or atraumatic instability. With careful attention to arthroscopic capsular management, adequate exposure can be achieved and reproducibly allow for an effective capsular repair when indicated. [ABSTRACT FROM AUTHOR]

Purpose: Posterolateral corner structures functionally interact with the ACL. The aim of this study was to investigate the capability of an isolated ACL reconstruction control laxity parameters in a knee with combined ACL and PLC and the increase in terms of laxity produced by the resection of the PC in an ACL-deficient knee.Method: An in vitro cadaveric study was performed on seven knees. The joints were analysed in the following conditions: intact, after ACL resection, after popliteus complex resection, after ACL reconstruction and after LCL. Testing laxity parameters were recorded with an intra-operative navigation system and defined as: AP displacement at 30° and 90° of flexion (AP30 and AP90) applying a 130 N load and IE at 30° and 90° of knee flexion with a 5 N load.Results: Sectioning the ACL significantly increased the AP30 at 30° and 90° of knee flexion (p < 0.05). At 90° of knee flexion, the resection of the LCL determined a significant increase in terms of AP laxity (p < 0.05). At 90° has been found a significant difference for the IE laxity (p < 0.05) after PC resection. Sectioning the LCL produced a significant increase in IE laxity at 30° and 90° of knee flexion (p < 0.05).Conclusion: Isolated ACL reconstruction is able to control the AP laxity with a combined complete lesion of the PLC at 30° of knee flexion, but not at higher angle of knee flexion. Considering the IE rotations, the reconstruction was not sufficient not even to control a partial lesion of the PLC. These findings suggest that additional surgical procedures should be considerate even when facing combined PLC lesion. [ABSTRACT FROM AUTHOR]

Purpose: To assess whether the use of an articulated external fixator provides improvements in the mobility, stability and subjective function of patients undergoing ligament reconstruction.Methods: Thirty-three patients with sub-acute and chronic knee dislocation were subjected to multi-ligament reconstruction surgery. These patients were randomly allocated to two groups for immobilization after reconstruction: group 0-control (18 patients), with rigid knee bracing, and group 1-articulated external fixator (15 patients). The stability of the reconstructed ligaments was assessed after at least 14 months (26.6-month average) postoperatively by physical examination. Deficit of extension and flexion was measured in relation to the unaffected contralateral knee, and the Lysholm knee scoring scale questionnaire was applied.Results: There was no difference in the assessment of joint stability between the groups. In group 1, patients showed less flexion deficit (4.8° ± 5.4° vs. 18.2° ± 14.8°, p < 0.05), and the percentage of patients with a flexion deficit of 5° or less were higher compared with group 0 (64 vs. 18 %, p < 0.05). There was no difference between groups in relation to extension loss. Group 1 also presented better Lysholm scores, with 73 % of patients rated as excellent or good compared with 35 % in group 0 (p < 0.05).Conclusions: Compared with the control rehabilitation protocol with rigid knee bracing in extension, the use of an articulated external fixator in the treatment of chronic multi-ligament-injured knees provided the same ligament stability, better final range of motion and improved Lysholm score. Patients presenting with chronic multi-ligament instability should be considered for articulated external fixation to supplement reconstruction procedures.Level Of Evidence: Randomized controlled trial, Level I. [ABSTRACT FROM AUTHOR]

Background: Reconstruction of the medial patellofemoral ligament (MPFL) is an established operative procedure for patients with recurrent episodes of lateral patellar instability. However, recent articles have reported remarkable complication rates, with nonanatomic femoral tunnel positioning in up to 64% of patients. Purpose: To evaluate the sensitivity of femoral tunnel placement using lateral fluoroscopic guidance to minor degrees of deviation from the true-lateral view using established radiographic landmarks. Study Design: Controlled laboratory study. Methods: Six human cadaveric femora were used for this study. A 6-mm radiopaque eyelet was used to mark the native femoral insertion of the MPFL according to previously described radiographic landmarks. Radiographic landmarks were also applied with the femur positioned in 2.5° and 5° of internal and external rotation, respectively, and with the femur in 2.5° and 5° of hip abduction and adduction, respectively. The distance between the center of the 6-mm eyelet to the center of the native femoral MPFL insertion, as established in the true-lateral view, was measured and determined as the degree of shift in each position. Results: Hip adduction, abduction, and internal and external rotations of 2.5° resulted in a shift from the native femoral MPFL insertion point to a more distal (adduction), proximal (abduction), anterior (internal rotation), and posterior location (external rotation) of 2.7 ± 0.7, 2.0 ± 0.7, 2.7 ± 1.1, and 3.0 ± 1.3 mm, respectively (all P < .05). Malpositioning increased to a distance of 5.0 ± 0.7 mm distally, 3.6 ± 1.0 mm proximally, 5.2 ± 0.8 mm anteriorly, and 6.2 ± 0.6 mm posteriorly to the native insertion point when the attachment was marked with 5° of divergence from the true-lateral view (all P < .05). Conclusion: The results of this study indicate the high sensitivity of femoral tunnel placement using lateral fluoroscopic guidance to minor degrees of deviation from the true-lateral view. Clinical Relevance: The study highlights the importance of an exact lateral view when fluoroscopic guidance is used for femoral tunnel positioning in the daily practice of MPFL reconstruction, and a possible explanation for the high incidence of nonanatomic tunnel placement is suggested. [ABSTRACT FROM AUTHOR]

Background: Reconstruction of the medial patellofemoral ligament (MPFL) using free tendon grafts has become a widespread treatment option for patellofemoral instability. As the numbers of cases gradually grow, so do the reports of possible peri- and postoperative complications following this procedure.Objective: The present review summarizes all known complications of MPFL reconstruction with regard to postoperative outcome and seeks to highlight possible pitfalls that may occur during treatment.Conclusions: MPFL reconstruction generally has to be regarded as a safe procedure today due to low patellar re-dislocation rates. Complication rates however are not trivial owing to the complexity of the underlying pathology. Complications can arise from graft fixation or femoral tunnel placement. Postoperative flexion deficits and medial knee pain have been described as predominant complaints. Anatomical preconditions as the grade of trochlear dysplasia, axis or torsion of the lower extremity have to be considered in search of causes for possible graft failure as well as in the thorough preoperative planning of the procedure. [ABSTRACT FROM AUTHOR]

Background: Little is known about the long-term results of surgical correction of hallux valgus deformity, in particular, the recurrence rate and factors leading to recurrence. Methods: Of one hundred and eight patients (115 feet) who underwent a Scarf osteotomy, ninety-three patients (ninety-three feet) were examined at an average duration of follow-up of 124 months. Clinical examination before surgery and at the time of final follow-up included an evaluation of range of motion, pain as measured with a visual analog scale, and American Orthopaedic Foot & Ankle Society (AOFAS) scores. The Foot and Ankle Outcome Score (FAOS) was also assessed postoperatively. Radiographic data were evaluated preoperatively, at six weeks postoperatively, and at the time of final follow-up. Additional radiographic data were available for seventy-nine patients of the same patient cohort at an average of twenty-seven months postoperatively. Results: The median overall AOFAS score improved from 57 points preoperatively to 95 points at the time of final follow-up. All radiographic measurements (hallux valgus angle [HVA], intermetatarsal angle [IMA], distal metatarsal articular angle [DMAA], and sesamoid bone position) showed significant (p < 0.05) improvement at the time of final follow-up compared with preoperatively. The rate of recurrence (an HVA of ?20°) at the time of final follow-up was 30%. We were unable to determine if recurrence resulted in functional impairment or consequences for quality of life. Conclusions: The recurrence rate after ten years was 30%, and a higher final HVA resulted in higher pain levels. The limitations imposed by nonvalidated outcome measures precluded conclusions about the influence of HVA on function or quality of life. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the influence of lateral retinacular release and medial and lateral retinacular deficiency on patellofemoral position and retropatellar contact pressure. Human knee specimens (n = 8, mean age = 65 SD 7 years, all male) were tested in a kinematic knee-simulating machine. During simulation of an isokinetic knee extension cycle from 120 degrees to full extension, a hydraulic cylinder applied sufficient force to the quadriceps tendon to produce an extension moment of 31 Nm. The position of the patella was measured using an ultrasound based motion analysis system (CMS 100, Zebris). The amount of patellofemoral contact pressure and its pressure distribution was measured using a pressure sensitive film (Tekscan, Boston). Patellar position and contact pressure were first investigated in intact knee conditions, after a lateral retinacular release and a release of the medial and lateral retinaculum. After lateral retinacular release the patella continuously moved from a significant medialised position at flexion (P = 0.01) to a lateralised position (P = 0.02) at full knee extension compared to intact conditions, the centre of patellofemoral contact pressure was significantly medialised (0.04) between 120 degrees and 60 degrees knee flexion. Patellofemoral contact pressure did not change significantly. In the deficient knee conditions the patella moved on a significant lateralised track (P = 0.04) through the entire extension cycle with a lateralised centre of patellofemoral pressure (P = 0.04) with a trend (P = 0.08) towards increased patellofemoral pressure. The results suggest that lateral retinacular release did not inevitably stabilise or medialise patellar tracking through the entire knee extension cycle, but could decrease pressure on the lateral patellar facet in knee flexion. Therefore lateral retinacular release should be considered carefully in cases of patellar instability. [ABSTRACT FROM AUTHOR]

This study compares the effects of two different techniques of medial patellofemoral ligament (MPFL) reconstruction, and proximal soft tissue realignment on patellar stabilization against lateral dislocation. Eight human cadaver knee specimens with no radiological pathomorpholgy on a straight lateral view, contributing to patellofemoral instability, were mounted in a kinematic knee simulator and isokinetic extension was simulated. Patellar kinematics were measured with an ultrasound positioning system (zebris) while a 100 N laterally directed force was applied to the patella. The kinematics were compared with intact knee conditions under MPFL deficient conditions, as well as following dynamic reconstruction of the MPFL using a distal transfer of the semitendinosus tendon, following static reconstruction by a semitendinosus autograft, and following proximal soft tissue realignment of the patella (Insall procedure). Dynamic reconstruction of the MPFL resulted in no significant alteration (P = 0.16) of patellar kinematics. Static reconstruction of the MPFL significantly medialized (P < 0.01) the patellar movement without, but restored intact knee kinematics under the laterally directed force. In contrast, following proximal soft tissue realignment, the patellar movement was constantly medialized and internally tilted (P = 0.04). Dynamic and static reconstruction of the MPFL create sufficient stabilization of the patella. Following proximal soft tissue realignment, the patellar position was over-medialized relative to intact knee conditions, which could lead to an overuse of the medial retropatellar cartilage. [ABSTRACT FROM AUTHOR]

Multiligament knee injuries are rare but potentially limb-threatening conditions. In this study we aim to evaluate the mid- and long-term functional outcome of patients who underwent arthroscopically assisted multiple ligament reconstruction for chronic multiple knee ligament deficiency. Thirty-five patients (27 males and 8 females) with an average age of 35.1 years (range: 17-60) were included in this study. Follow-up ranged from 12 to 124 months (average: 40.3). On final follow-up patients had a mean loss of extension of 3.1 degrees , while flexion ranged from 95 degrees to 135 degrees (average: 118.4 degrees ). The functional outcome according to Clancy's criteria was excellent in 7 patients (20%), good in 14 (40%), fair in 11 (31.4%), while 3 reconstructions resulted in failure (8.6%). Patients scored an average of 4.03 (range: 1-9) in their Tegner Activity Scale, while their score in Activities of Daily Living Scale of the Knee Outcome Survey ranged from 25 to 98 with an average of 72.7. Sixteen patients returned to sporting activities and all but three returned to work. Early operative treatment of multiple ligament injuries is preferable, as it may allow for anatomic repair instead of reconstruction of ligamentous structures. This study demonstrates though, that even if acute reconstruction has not or could not be performed, reconstruction in chronic multiple ligament deficient knees should be attempted. Although this complex and technically demanding procedure rarely results in a "normal" knee, it offers in most cases very satisfactory stability and a significant improvement in knee function. [ABSTRACT FROM AUTHOR]

The purpose of the study was to evaluate the mid-term results of surgical treatment in different groups of patients with multiple knee ligament injuries. Review of our patients’ records revealed that 48 acute and chronic patients were surgically treated for combined knee injury. Due to severe capsular damage in these injuries, open techniques were used. In our treatment protocol, avulsed ligaments and tears of the posterolateral and posteromedial corner were repaired if possible, whereas midsubstance tears of cruciate ligaments and chronic cases were reconstructed with autografts. Postoperatively, an accelerated program of rehabilitation was introduced, aiming to progressively mobilize the joint and improve muscle endurance. For the follow-up evaluation we designed a protocol composed of two parts. In the first part, anatomical lesions were recorded and in the second part, clinical evaluation was performed using the Lysholm score, the Tegner rating system, the IKDC evaluation form, and the KT1000. Student’s t tests and chi-square tests were used for data analysis. Forty-eight patients (mean age 28.6±11.9 years; 41 males) were classified according to the specific anatomical structures involved. Group A included 12 anterior cruciate ligament (ACL) and medial structure injuries, group B included 11 ACL or posterior cruciate ligament (PCL) ruptures combined with posterolateral injuries, and group C consisted of 25 knee dislocations (ACL and PCL ruptures which might be combined with damage of the collateral ligaments). Thirty-eight patients were surgically treated during the acute phase and ten patients were treated chronically. Forty-four patients (91.6%) were followed up at a mean of 51.3±29.9 months. Average Lysholm score was 87±12.3; average Tegner score was 5.09±2.19 before accident and 4.34±2.12 in re-examination; IKDC score was A in 10 cases, B in 22, C in 6, and D in 6. The mean range of motion was 129.9°±12.5°. The average loss of extension and flexion were 1.6°±2.5° and 7.6°±7.9°, respectively. The side-to-side difference in corrected anterior and posterior translation in quadriceps neutral angle and in anterior translation in 30° angle was <3 mm for about 65% of our patients. Surgical treatment of multiple knee ligament injuries, using autografts, provided satisfactory stability, range of motion, and subjective functional results. However, despite the improvement of the quality of life, the preinjury patients’ activity level was not fully obtained in re-examination. Patients underwent surgical treatment during the acute phase had better scores in several points, but finally there was no statistical significance between acute and chronic patients. Moreover, no statistically significant differences were observed among the groups with specific damaged anatomical structures. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of the biceps femoris tenodesis and popliteofibular ligament reconstruction on knee biomechanics. Ten human cadaveric knees were tested in the intact, posterolateral corner (PLC)-deficient, and PLC-reconstructed conditions using a robotic/universal force moment sensor testing system. The knees were subjected to: (1) a 134 N posterior tibial load, and (2) a 10 Nm external tibial torque applied to the tibia at full extension, 30 degrees and 90 degrees of flexion. External tibial rotation of the intact knee ranged from 18.3+/-4.6 degrees at full extension to 27.9+/-4.6 degrees at 30 degrees under the 10 Nm external tibial torque. These values increased after sectioning the PLC by 2.8 degrees -7.5 degrees at 30 degrees and 90 degrees respectively. After the popliteofibular ligament reconstruction, external tibial rotation values were not significantly different from those for the intact knee at any angle tested, while values following the biceps tenodesis were as much as 5.7 degrees greater than the intact knee. Under the 134 N posterior tibial load, there were minimal decreases in posterior tibial translation of up to 0.9 mm with the biceps tenodesis and up to 1.6 mm with the popliteofibular ligament reconstruction compared to the intact knee. The in situ forces in the biceps tenodesis were not significantly different than the intact PLC at full extension or 30 degrees, while the in situ forces in the popliteofibular graft were not significantly different at any flexion angle. Our data suggests that by restoring external tibial rotation the popliteofibular ligament reconstruction more closely reproduces the primary function of the PLC as compared to the biceps tenodesis. [ABSTRACT FROM AUTHOR]