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To evaluate the degree of correlation between MRI and clinical gradings of medial collateral ligament (MCL) injuries and assess for associated structures on MRI which may influence the clinical perception of MCL laxity. All knee MRIs with acute MCL injuries between 2016 and 2020 at our centre were retrospectively reviewed by two blinded musculoskeletal radiologists. The clinic notes were reviewed for clinical gradings. One hundred and nineteen MRIs included. Forty-eight percent (57/119) agreement between MRI and clinical gradings (κ = 0.21, standard error (SE) 0.07). MRI grades: I 29% (34/119), II 50% (60/119), III 21% (25/119). Clinical grades: I 67% (80/119), II 26% (31/119), III 7% (8/119). In patients with clinical grade III MCL injury, there was waviness of the superficial MCL on MRI in 100% (8/8), deep meniscofemoral ligament tear in 75% (6/8), anterior cruciate ligament (ACL) partial or complete tear in 75% (6/8) and posteromedial corner (PMC) injury in 100% (8/8); compared with 0% (0/111), 34% (38/111), 44% (49/111) and 41% (46/111) respectively in clinical grade I or II injuries (p

INTRODUCTION This study aimed to describe an anatomic medial knee reconstruction technique for combined anterior cruciate ligament (ACL) and grade III medial collateral ligament (MCL) injuries and to assess knee function and stability restoration in patients who underwent primary MCL reconstruction compared with primary repair. METHODS A total of 105 patients who had undergone anatomic ACL reconstruction between 2008 and 2017 were enrolled in this retrospective study and divided into two groups according to concomitant MCL ruptures. Group A included patients with isolated ACL ruptures without MCL injuries. Group B included patients with both ACL and MCL injuries, and it was subdivided into three groups according to the severity of the MCL injury and treatment modality: B-1, grade I or II MCL injury treated conservatively; B-2: grade III MCL injury treated by primary MCL repair; and B-3: grade III MCL injury treated by primary reconstruction. Knee stability was measured via Telos valgus radiography at 6-month and 2-year postoperative. The Lysholm score, Tegner activity level, Likert scales (satisfaction), and return to previous sports were evaluated at 2-year postoperative. RESULTS At 6-month postoperative, there was no significant difference in medial laxity between the B-2 and B-3 groups. However, at 2-year postoperative, medial laxity were significantly higher both at 30° of flexion (5.2° versus 2.2°, p = 0.020) and at full extension (3.4° versus 1.1°, p

Introduction The primary aim of this investigation was to systematically review relevant literature of various imaging modalities (magnetic resonance imaging (MRI), stress radiography and ultrasonography) in the assessment of patients with a medial collateral ligament (MCL) injury. Materials and methods A systematic literature review of articles indexed in PubMed and Cochrane library was performed. Original research reporting data associated with medial gapping, surgical, and clinical findings associated with MCL injuries were considered for inclusion. The methodological quality of each inclusion was also assessed using a verified tool. Results Twenty-three imaging studies (magnetic resonance imaging (MRI) n = 14; ultrasonography n = 6; radiography n = 3) were ultimately included into the review. A total of 808 injured, and 294 control, knees were assessed. Interobserver reliabilities were reported in radiographic and ultrasonographic investigations with almost perfect agreement. MRI studies demonstrated agreement ranging between substantial to almost perfect. Intraobserver reliability was only reported in radiographic studies pertinent to medial gapping and was found to be almost perfect. Correlation of MRI with clinical findings was moderate to strong (65–92%). Additionally, MRI imaging was more sensitive in the detection of MCL lesions when compared to clinical examination. However, when compared to surgical findings, MRI underestimated the grade of instability in up to 21% of cases. Furthermore, MRI showed relatively inferior performance in the identification of the exact MCL-lesion location when compared to surgical findings. Interestingly, preoperative clinical examination was slightly inferior to stress radiography in the detection of MCL lesions. However, clinical testing under general anaesthesia performed similar to stress radiography. The methodological quality analysis showed a low risk of bias regarding patient selection and index testing in each imaging modality. Conclusion MRI can reliably diagnose an MCL lesion but demonstrates limitations in its ability to predict the specific lesion location or grade of MCL instability. Ultrasonography is a widely available, radiation free modality, but is rarely used in clinical practice for detecting MCL lesions and clinical or surgical correlates are scarce. Stress radiography findings correlate with surgical findings but clinical correlations are missing in the literature. Level of evidence IV.

To investigate the incidence of bone bruising with isolated medial collateral ligament injury and to assess whether the presence of bone bruising is related to the injury grade. Patients who sustained an acute isolated medial collateral ligament injury demonstrated on knee MRI between 2016 and 2020 were included in this study. Patient’s characteristics and injury classification (clinical and radiological) were reviewed from clinical notes and imaging. The patients were divided into two groups, based on the presence of bone bruising. Fisher’s exact test was used for dichotomous variables and odds ratios were computed in areas of clinical significance. Sixty patients with a median age of 37.6 ± 13.8 were included. Twenty-eight (46.7%) had bone bruising demonstrated on MRI scan. The bone bruising group were 7 times (95% CI [1.4;36.5]) more likely to have a complete disruption of the superficial medial collateral ligament and MRI grade III injury. Injury to the deep medial collateral ligament was more often observed in this group (p

To identify the posterior oblique ligament and assess incidence and patterns of injury to the ligament on MRI of acute knee trauma. One hundred twenty-three MRI studies met the study criteria. For each case, the posterior oblique ligament was identified and scored as injured or normal. Incidence of proximal and distal posterior oblique ligament tears was calculated. Fisher’s tests were employed to determine significance of association between tears of the posterior oblique ligament and components of the posteromedial corner and other capsuloligamentous structures of the knee. The posterior oblique ligament was reliably identified as a distinct structure in 123 MRI scans that met the criteria and was consistently labeled as intact or torn. Posterior oblique ligament tear was seen in 61.7% of knee trauma with proximal injury in 56.5% and distal injury in 97.3% of positive cases. Posterior oblique ligament disruption was a part of multiligamentous injury in 94.7% of positive cases. Posterior oblique ligament injuries (n = 76) had an extremely significant relationship with oblique popliteal ligament tears (n = 27) (p = 0.0001), semimembranosus tendon insertion tears (n = 15) (p = 0.0005), and medial collateral ligament tears (n = 15) (p = 0.0005) and a highly significant association with medial meniscus tears (n = 68) (p = 0.0049) and posterior cruciate ligament tears (n = 12) (p = 0.0033). The association with anterior cruciate ligament tears (n = 53) was not significant. The posterior oblique ligament is a distinct radiological entity consistently identified in acute trauma MRI. Disruptions of the distal posterior oblique ligament are frequent in complex knee injury, notably in association with oblique popliteal ligament, medial collateral ligament, and semimembranosus tendon tears.

Kinematically aligned total knee arthroplasty (KA TKA) targets restoration of patient-specific alignment and soft tissue laxity. However, whether KA TKA reproduces native soft tissue strain remains unclear. This cadaveric study tested the hypothesis that KA TKA would better restore the quantitative strain and strain distribution of medial collateral ligament (MCL) to the native healthy knee compared to mechanically aligned (MA) TKA. Twenty-four fresh-frozen cadaver knees (12 pairs) were mounted on a customized knee squatting simulator to measure MCL strain during flexion. For each pair, one knee was assigned to KA TKA and the other to MA TKA. During KA TKA, the amount of femur and tibia resected was equivalent to implant thickness without MCL release using the calipered measuring technique. MA TKA was performed using conventional measured resection techniques. MCL strain was measured using a video extensometer (Mercury® RT RealTime tracking system, Sobriety s.r.o, Czech Republic). MCL strain and strain distribution during knee flexion were measured, and the measurements compared between native and post-TKA conditions. Mean and peak MCL strain were similar between KA TKA and native knees at all flexion angles (p > 0.1 at all flexion angles) while mean strain at all flexion angles and peak strain at ≥ 60o of MA TKA were approximately twice those of the native knees (p

There is a paucity of literature demonstrating which factors are associated with signs of elbow instability on magnetic resonance imaging (MRI) following simple elbow dislocations (SED). This study aimed to evaluate demographic variables and MRI datasets to identify factors associated with elbow instability following SEDs. This retrospective multicenter MRI study included patients who had sustained SED and presented within 21 days of trauma. Measurements included ulnohumeral angle, drop sign, and radiocapitellar and ulnohumeral incongruity. The coronoid tip (Regan Morrey type I), lateral collateral ligament (LCL), common extensor origin (CEO), medial collateral ligament (MCL,) and common flexor origin (CFO) were assessed for injuries. Simple and multiple logistic regression analyses were performed to identify factors associated with signs of elbow instability (e.g., ulnohumeral incongruity > 1 mm) on MRI. A total of 147 patients (68 women, 79 men) with a mean age of 42.9 years (range, 17–85) were included. Of those, 62 patients (42.2%) demonstrated radiocapitellar (> 2 mm) and 36 patients (25.5%) demonstrated ulnohumeral incongruity (> 1 mm); 17 patients (11.6%) had a drop sign (≥ 4 mm). All patients with elbow instability on MRI had injury to the CEO and/or CFO. In multiple logistic regression, an ulnohumeral angle of ≤ 45° (p = 0.005; OR: 4.95), injury to the CEO (p

A subsystem impactor test for pedestrian lower limb injury evaluation has been brought in China New Car Assessment Protocol (CNCAP). Concerning large anthropometric differences of the people from different countries, the present study aims to establish and validate a finite element lower limb model representing 50th Chinese male size for pedestrian safety research, then compare its biomechanical responses with the general models currently in wide use in the world for pedestrian safety evaluation. Concerning the vehicle-pedestrian impact loading environment, the previously developed lower limb model with three-dimensional muscles was adjusted and validated through the related experiments. Then, the biomechanical responses of the validated model were compared with the Total Human Model for Safety (THUMS) and Advanced Pedestrian Legform Impactor (aPLI) models by combing with four typical vehicles. The results showed that both consistency and significant differences of biomechanical responses existed between the present model and the other two models. The injury measurements of the thigh region of the present model showed extremely large differences with the other two models, while the tibia and Medial Collateral Ligament (MCL) injury measurements show similar values. Thus, it can be concluded that directly using the aPLI or THUMS models for Chinese pedestrian safety evaluation is not robust concerning both kinematic responses and injury measurements.

Purpose We aim to determine a reference data set for normal medial collateral ligament (MCL) stiffness values using shear wave elastography (SWE). Methods Quantitative stiffness of the MCL was measured at three levels: the proximal (MCL area from the level of the medial meniscus to the level of the femoral attachment), the middle (MCL area at the level of the medial meniscus), and the distal (MCL area from the level of the medial meniscus to the level of the tibial attachment) segments of the MCL at a knee position of 0 degrees. Results A total of 60 MCL of 30 healthy volunteers (15 female, 15 male) were examined. The mean stiffness values of the proximal, middle, and distal MCL for observer 1 were 32.25 +/- 6.44, 34.25 +/- 6.84, and 35.47 +/- 6.98, respectively. The mean stiffness values of the proximal, middle, and distal MCL for observer 2 were 33.56 +/- 6.76, 35.44 +/- 6.91, and 36.32 +/- 7.04, respectively. Conclusion SWE has a strong potential to be a method of choice for evaluating MCL stiffness. Our study participants were healthy volunteers and the data can be used as reference data for future studies.

Literature regarding medial collateral ligament (MCL) injuries is focused on adults with superficial MCL disruptions. However, children follow different injury patterns, with avulsion fractures at ligament attachment sites occurring commonly. Such avulsions have not been characterized for pediatric MCL injuries. To elucidate imaging findings, and review management and outcomes of pediatric MCL avulsion fractures. We conducted a 10-year retrospective review of knee magnetic resonance (MR) imaging reports for patients younger than 16 years old diagnosed with acute MCL avulsion fracture. MR imaging was reviewed to confirm and characterize the components of the avulsion (perichondrium without or with cartilage, and/or bone) and to identify additional knee injuries. Radiographs, if available, from the time of injury were reviewed. Clinical management and patient outcomes were recorded. Eighteen patients (13 boys, 5 girls) incurred an acute MCL avulsion fracture. All avulsions involved the deep MCL attachment: 17 meniscofemoral and 1 meniscotibial component. Two avulsions also included the superficial MCL attachment. Nine boys had non-osseous avulsions, all radiographically occult. All girls had radiographically apparent avulsions. Three girls and three boys sustained associated knee derangements, most commonly anterior cruciate ligament (ACL) injury (n=4). All MCL avulsions were initially treated conservatively; one child required subsequent surgery for ongoing pain. Pediatric MCL avulsion fractures in this study uniformly involve the attachment of the deep MCL and can be entirely non-osseous, particularly in boys who lag in skeletal maturity, making these injuries radiographically occult. MR imaging may be required to recognize these avulsions, which can impact the duration of rest and knee bracing.

To determine the risk factors for lateral meniscus and root tears in patients with acute anterior cruciate ligament (ACL) injuries. A total of 226 patients undergoing acute ACL reconstruction were included in the study sample. Exclusion criteria were revisions, fractures, chronic cases, and multiple ligament injuries, with the exception of medial collateral ligament (MCL) injuries. The patients were divided into groups based on the presence of lateral meniscus and root tears by arthroscopy. Binary logistic regression was used to analyze risk factors including age, sex, body mass index (BMI), injury mechanism (contact/non-contact), Segond fracture, side-to-side laxity, location of bone contusion, medial and lateral tibial and meniscal slope, mechanical axis angle, and grade of pivot shift. Overall lateral meniscus (LM) tears were identified in 97 patients (42.9%), and LM root tears were found in 22 patients (9.7%). The risk of an LM tear in ACL-injured knees increased with bone contusion on LTP (odds ratio [OR], 3.5; 95% confidence interval [CI] 1.419–8.634; P = 0.007), steeper lateral tibial slope (OR, 1.133; 95% CI 1.003–1.28; P = 0.045), MCL injury (OR, 2.618; 95% CI 1.444–4.746; P = 0.002), and non-contact injury mechanism (OR, 3.132; 95% CI 1.446–6.785; P = 0.004) in logistic regression analysis. The risk of LM root tear in ACL-injured knees increased with high-grade pivot shift (OR, 9.127; 95% CI 2.821–29.525; P = 0.000) and steeper lateral tibial slope (OR, 1.293; 95% CI 1.061–1.576; P = 0.011). The increased risk of LM lesions in acute ACL-injured knees should be considered if significant risk factors including bone contusion on lateral compartments, MCL injury, and a steeper lateral tibial slope are present. Moreover, high-grade rotational injury with steeper lateral tibial slope are also significant risk factors for LM root tears, and therefore care should be taken by clinicians not to miss such lesions. III.

Various reconstruction techniques have been employed to restore normal kinematics to PCL-deficient knees; however, studies show that failure rates are still high. Damage to secondary ligamentous stabilizers of the joint, which commonly occurs concurrently with PCL injuries, may contribute to these failures. The main objective of this study was to quantify the biomechanical contributions of the deep medial collateral ligament (dMCL) and posterior oblique ligament (POL) in stabilizing the PCL-deficient knee, using a joint motion simulator. Eight cadaveric knees underwent biomechanical analysis of posteromedial stability and rotatory laxity using an AMTI VIVO joint motion simulator. Combined posterior force (100 N) and internal torque (5 Nm) loads, followed by pure internal/external torques (± 5 Nm), were applied at 0, 30, 60 and 90° of flexion. The specimens were tested in the intact state, followed by sequential sectioning of the PCL, dMCL, POL and sMCL. The order of sectioning of the dMCL and POL was randomized, providing n = 4 for each cutting sequence. Changes in posteromedial displacements and rotatory laxities were measured, as were the biomechanical contributions of the dMCL, POL and sMCL in resisting these loads in a PCL-deficient knee. Overall, it was observed that POL transection caused increased posteromedial displacements and internal rotations in extension, whereas dMCL transection had less of an effect in extension and more of an effect in flexion. Although statistically significant differences were identified during most loading scenarios, the increases in posteromedial displacements and rotatory laxity due to transection of the POL or dMCL were usually small. However, when internal torque was applied to the PCL-deficient knee, the combined torque contributions of the dMCL and POL towards resisting rotation was similar to that of the sMCL. The dMCL and POL are both important secondary stabilizers to posteromedial translation in the PCL-deficient knee, with alternating roles depending on flexion angle. Thus, in a PCL-deficient knee, concomitant injuries to either the POL or dMCL should be addressed with the aim of reducing the risk of PCL reconstruction failure.

© 2021, European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA). Purpose: Chronic grade 3 tears of the medial collateral ligament and posterior oblique ligament may result in valgus laxity and anteromedial rotational instability after an isolated or multiligament injury. The purpose of this study was to prospectively analyze the restoration of physiologic medial laxity as assessed on stress radiography and patient reported subjective functional outcomes in patients who undergo an anatomic medial knee reconstruction. Methods: This was a prospective study which included patients with chronic (> 6 weeks old) posteromedial corner injury with or without other ligament and meniscus lesions. Pre- and post-operative valgus stress radiographs were performed in 20° knee flexion and functional outcome was recorded as per the International Knee Documentation Committee (IKDC) and Lysholm scores. All patients underwent anatomic medial reconstruction with two femoral and two tibial sockets using ipsilateral hamstring tendon autograft. Simultaneous ligament and meniscus surgery was performed as per the associated injury pattern. All patients were followed up for a minimum of 24 months post-surgery. Results: Thirty-four patients (23 males, 11 females) were enrolled in the study and all were available till final follow-up of mean 49.7 ± 14.9 months. The mean age was 30.6 ± 7.9 (18–52 years). Two patients had isolated medial sided lesions and 23 had associated ligament injuries. The mean follow up was 49.7 (24–72) months. The mean IKDC score improved from 58 ± 8.3 to 78.2 ± 9.5 (p < 0.001). Post-operatively there were 15 excellent, 11 good and 8 fair outcomes on Lysholm score. The mean pre-operative valgus side-to-side opening improved from 7.5 ± 2.5 mm to 1.2 ± 0.7 mm on stress radiography (p < 0.001). Conclusion: Anatomic reconstruction of the superficial medial collateral and posterior oblique ligaments restore stability in a consistent manner cases of chronic grade 3 instability. The objective functional results, subjective outcomes and measures of static medial stability are satisfactory in the short term. Level of Evidence: IV

Aim of this study was to compare outcomes of a newer technique of pie-crusting of the femoral origin of medial collateral ligament (MCL) with the conventional medial release, for correcting varus deformity during total knee arthroplasty. Null hypothesis was that there is no difference in clinical outcomes between these two techniques. All patients requiring an additional medial release after excision of osteophytes and release of deep MCL during total knee arthroplasty were allocated into two groups, alternately. Each group composed of 40 patients. Pie-crusting with a needle was done near the femoral attachment of superficial MCL in group-1, whereas the group-2 underwent classic sub-periosteal release of the tibial insertion of superficial MCL. All the patients were assessed for any laxity (more than 3 mm opening) intraoperatively or at one-year follow-up, pain score at 12 and 24 h after the surgery, Knee Society Score, Western Ontario and McMaster Universities Arthritis Index and range of motion 12 months after the surgery. None of the patients showed any signs of laxity or failure at one-year follow-up. Pain scores were slightly better (not statistically significant) in the group-1. However, no differences were noted in functional outcomes scores. Pie-crusting of superficial MCL is a safe, controlled and less invasive approach for medial soft tissue release. When knee deformity is not correctable with initial soft tissue release, this is an appropriate next surgical step. There does not appear to be a risk of over-release during the surgery or afterward. Non-randomized controlled trial, Level II.

PurposeThe purpose of this study was to examine the length change patterns of the native medial structures of the knee and determine the effect on graft length change patterns for different tibial and femoral attachment points for previously described medial reconstructions.MethodsEight cadaveric knee specimens were prepared by removing the skin and subcutaneous fat. The sartorius fascia was divided to allow clear identification of the medial ligamentous structures. Knees were then mounted in a custom-made rig and the quadriceps muscle and the iliotibial tract were loaded, using cables and hanging weights. Threads were mounted between tibial and femoral pins positioned in the anterior, middle, and posterior parts of the attachment sites of the native superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL). Pins were also placed at the attachment sites relating to two commonly used medial reconstructions (Bosworth/Lind and LaPrade). Length changes between the tibiofemoral pin combinations were measured using a rotary encoder as the knee was flexed through an arc of 0–120°.ResultsWith knee flexion, the anterior fibres of the sMCL tightened (increased in length 7.4% ± 2.9%) whilst the posterior fibres slackened (decreased in length 8.3% ± 3.1%). All fibre regions of the POL displayed a uniform lengthening of approximately 25% between 0 and 120° knee flexion.The most isometric tibiofemoral combination was between pins placed representing the middle fibres of the sMCL (Length change = 5.4% ± 2.1% with knee flexion). The simulated sMCL reconstruction that produced the least length change was the Lind/Bosworth reconstruction with the tibial attachment at the insertion of the semitendinosus and the femoral attachment in the posterior part of the native sMCL attachment side (5.4 ± 2.2%). This appeared more isometric than using the attachment positions described for the LaPrade reconstruction (10.0 ± 4.8%).ConclusionThe complex behaviour of the native MCL could not be imitated by a single point-to-point combination and surgeons should be aware that small changes in the femoral MCL graft attachment position will significantly effect graft length change patterns. Reconstructing the sMCL with a semitendinosus autograft, left attached distally to its tibial insertion, would appear to have a minimal effect on length change compared to detaching it and using the native tibial attachment site. A POL graft must always be tensioned near extension to avoid capturing the knee or graft failure.

The cubital tunnel is limited anteriorly by the medial epicondyle (ME), laterally by the medial collateral ligament, and superiorly by Osborne’s fascia and the cubital tunnel retinaculum. Previous studies were mostly dedicated to the roof of the cubital tunnel, in the way that the study of the groove for ulnar nerve and ME anatomy is relatively scarce in the literature. We sought to describe the radiological anatomy of the groove for ulnar nerve and ME in healthy volunteers with multiplanar computed tomography (CT). We analyzed 3D CT images of 30 healthy volunteers (mean age 39 years, range 18–66 years). Nine variables were measured from the right elbow, including sizes, areas and angles in two different planes (coronal and axial). Mean ME width and length were 17.3 ± 3.5 mm and 31.7 ± 4.5 mm, respectively. According to categorical correlation studies, ME width (X) was deemed the most representative morphological characteristic because of the positive correlation to five other different anatomical measurements. A three-tiered anatomical classification was proposed based on data distribution. Large individual variation is found in the shape of ME, both in coronal and axial planes. The knowledge of individual osseous morphology is of great value potentially contributing to the surgical decision-making in patients affected by cubital tunnel syndrome.

Medial collateral ligament (MCL) injury is very common and surgical repair is sometimes necessary. Especially in the setting of simultaneous anterior cruciate ligament reconstruction (ACLR) as the ACL is the secondary restraint against valgus stress. The goal of this study was to evaluate knee biomechanics after suture repair of the MCL augmented with suture tape, as compared to MCL repair alone, in the setting of concomitant ACL reconstruction (ACLR). Fifteen fresh-frozen human cadaveric knees were tested using a six-degrees-of-freedom robotic system under four loadings: (a) an 89.0 N anterior tibial load, (b) a 5.0 Nm internal and external rotation torque, (c) a 10.0 Nm valgus load, (d) a 7.0 Nm valgus load combined with 5.0 Nm internal rotation torque as a static simulated pivot-shift. The tested conditions were ACLR with the following states: (1) MCL intact, (2) MCL deficient, (3) MCL Repair, and (4) MCL repair augmented with suture tape (MCL Repair + ST). Under the different knee loadings, the tibial displacement, and the force in either the intact MCL, suture repaired MCL or repaired MCL-suture tape complex was measured. While neither the MCL Repair nor the MCL Repair + ST restored valgus rotation to the MCL intact state, displacement was significantly smaller after MCL Repair + ST (p

The objective was to analyze the long-term clinical outcome of terrible triad injury of the elbow following surgical intervention with a single lateral approach. We treated twenty-five patients with terrible triad injury of the elbow from July 1, 2017, to June 30, 2020, and performed post hoc analysis. All patients underwent standardized surgery which entailed: plate fixation for the ulnar coronoid process, fixation or replacement of the radial head, and repair of the lateral ligament but not the medial collateral ligament. We followed up each patient for an average of 22.9 months (range, 12 to 36 months) after surgery. Patients had an average angle scope of elbow flexion and extension that ranged from 8° to 120°. Average pronation of the elbow was 75° (range, 10°–85°), and average supination was 72° (range, 25°–80°). Patient-reported outcome measures were excellent: the DASH and Mayo elbow performance score (MEPS) were 96%. We were unable to follow-up one patient (4%). Among the remaining 24 patients, one patient (4%) presented with heterotopic ossification and stiffness following arthrolysis in the elbow one year after the initial surgery. We did not observe any joint dislocation, subluxation, or joint instability in the elbow after surgery. The single lateral approach, a sequential surgery for terrible triad injury of the elbow, can improve initial stability of the elbow. Patients are able to perform rehabilitative exercises sooner in their recovery, which helps to reduce stiffness. Heterotopic ossification is also reduced.

This study aimed to evaluate injury patterns associated with Stieda avulsion fractures of the medial femoral condyle at the attachment of the proximal MCL. Knee radiographs and MRI scans of 11 patients with Stieda fractures were evaluated by two fellowship-trained MSK radiologists for fracture origin, integrity of the deep and superficial components of the MCL, medial retinacular structures, posterior oblique ligament, other ligamentous injuries, meniscal tears, and osteochondral injuries. The mechanism of injury and subsequent clinical management were recorded. Eight Stieda fractures only involved the meniscofemoral fibers of the deep MCL, two larger Stieda fractures related to both superficial and deep layers, and one fracture only involved the superficial layer. Posteromedial retinacular structures and posterior oblique ligament were injured in all cases. Eight had high-grade ACL injuries, but none had high-grade PCL nor FCL injuries. The proximal anterolateral ligament was injured in seven, including two with associated Segond fractures. Other injuries included posterolateral corner injuries in six, meniscal injuries in seven, and additional fractures in nine, most commonly ACL-associated impaction fractures in the lateral tibiofemoral compartment. None had high-grade chondral injury. None of the Stieda fractures were treated surgically, but four underwent subsequent ACL reconstruction. Stieda fractures most commonly involved the deep fibers of the MCL and were accompanied by moderate-to-high-grade injury of other MCL components. There was a high association with other ligamentous injuries, particularly the posterior medial retinacular structures, posterior oblique ligament, and ACL, and many were associated with additional fractures.

The concept of medial stabilizing technique total knee arthroplasty (MST-TKA) is to minimize the medial release without the superficial layer of medial collateral ligament (MCL). However, it is unclear at what stage the proper medial laxity is obtained during surgery. The purpose of this study was to investigate the implication of deep layer of MCL (dMCL) and osteophyte resection on medial laxity during MST-TKA. A total of 103 consecutive patients who underwent cruciate-retaining TKA using the navigation system were included. The intraoperative hip–knee–ankle (HKA) angle was recorded under three conditions (no stress, valgus, and varus stress) at four time points after the resection of the anterior cruciate ligament (ACL) and meniscus (1st evaluation), after the dMCL release (2nd evaluation), and after osteophyte resection on both the femoral and tibial side (3rd evaluation). To assess valgus laxity, the differences in intraoperative HKA angle between 1st and 2nd evaluation (stage 1) and between 2nd and 3rd evaluation (stage 2) were calculated. Under the valgus stress condition, the intraoperative HKA angle change in stage 2 was significantly larger than that in stage 1 in full extension (stage 1; − 0.5 ± 1.0°, stage 2; − 2.0 ± 1.3°, p

Purpose The knee joint still represents the most frequent anatomical injury location accounting for about one-third of all injuries in recreational alpine skiers. However, comprehensive information on current knee injury patterns in this populations is sparse. Methods During the winter seasons 2016/17 and 2019/20, this retrospective questionnaire-based study was conducted in an Austrian sportclinic situated in a large ski area. Among a cohort of 282 recreational skiers (51.8% females), all injuries were diagnosed by the use of magnetic resonance imaging. Additionally, data were recorded on anthropometric characteristics, the perceived speed at the moment of injury, type of fall, physical fitness, self-reported skill level and risk-taking behaviour. Results The anterior cruciate ligament (ACL) was injured in all knee injuries recorded. Of the total study sample, 64.5% (n = 182) were ACL injuries with concomitant injuries and about 35.5% (n = 100) were isolated ACL injuries, not involving any other structures of the knee joint. In general, most common concomitant injury diagnoses among ACL-injured recreational alpine skiers were injuries of the medial collateral ligament (MCL) (n = 92, 50.5%), medial meniscus (MM) (n = 73, 40.1%) and lateral collateral ligament (LCL) (n = 41, 22.5%). No significant differences regarding additionally recorded characteristics were found between ACL-injured individuals with concomitant injuries and those with isolated ACL injury. Conclusions Whereas, before the introduction of carving skis, the MCL was reported being the most common injured part of the knee, currently, the majority of knee injuries are ACL injuries accompanied by injury of other knee joint structures, i.e. the MCL, MM and LCL. Level of evidence Level III.

This study aimed to assess the rate of iatrogenic mid-substance superficial medial collateral ligament (sMCL) tear due to the medial pie-crusting technique during varus deformity total knee arthroplasty and compare the knee society score (KSS), range of motion (ROM), and instability rate of the repaired group to the control group with intact sMCL. For this retrospective series of prospectively collected data, the multiple needle puncturing technique was performed for 653 out of the 1768 knees during algorithmic medial soft-tissue release. Iatrogenic tear was observed in 35 knees (5%); hence, repair with running locking nonabsorbable braided suture was performed. Patients were visited and reviewed both clinically and radiographically at 6 weeks, 3 months, 6 months, 12 months, and annually thereafter. Chi-square, ANOVA, Mann–Whitney, independent and paired t test were used to analyze the variables. P value

Purpose To define the length-change patterns of the superficial medial collateral ligament (sMCL), deep MCL (dMCL), and posterior oblique ligament (POL) across knee flexion and with applied anterior and rotational loads, and to relate these findings to their functions in knee stability and to surgical repair or reconstruction. Methods Ten cadaveric knees were mounted in a kinematics rig with loaded quadriceps, ITB, and hamstrings. Length changes of the anterior and posterior fibres of the sMCL, dMCL, and POL were recorded from 0° to 100° flexion by use of a linear displacement transducer and normalised to lengths at 0° flexion. Measurements were repeated with no external load, 90 N anterior draw force, and 5 Nm internal and 5 Nm external rotation torque applied. Results The anterior sMCL lengthened with flexion (p p p p p p p p Conclusion The structures of the medial ligament complex react differently to knee flexion and applied loads. Structures attaching posterior to the medial epicondyle are taut in extension, whereas the anterior sMCL, attaching anterior to the epicondyle, is tensioned during flexion. The anterior dMCL is elongated by external rotation. These data offer the basis for MCL repair and reconstruction techniques regarding graft positioning and tensioning.

Isolierte Verletzungen des tiefen Blattes des medialen Seitenbandes am Knie werden bei fehlender klinischer Instabilitat mehrheitlich konservativ mit gutem Ergebnis ausbehandelt. Ein 10-jahriges Madchen wurde bei dieser Verletzung initial ebenfalls konservativ gefuhrt. Bei ausbleibender Besserung der klinischen Symptomatik im Sinne von Schmerzen und Bewegungseinschrankung entschieden wir uns trotz fehlender Instabilitat zur chirurgischen Intervention. Es erfolgte die Entfernung eines kleinen osteochondralen Fragmentes am femoralen Ansatz des tiefen medialen kollateralen Ligaments (MCL)/Ligamentum meniscofemorale mediale. Das tiefe MCL wurde dann wieder am ursprunglichen Ansatz fixiert. Es zeigte sich anschliesend eine beschwerdefreie Patientin, mit stabilem frei beweglichem Kniegelenk. Auch in der Abschlusskontrolle 18 Monate postoperativ war die Patientin beschwerdefrei.

To delineate the spectrum of traumatic knee injuries associated with injury of the anterolateral ligament of the knee (ALL). A retrospective review of 200 MRI scans undertaken for acute knee trauma was performed. In each scan, the ALL was scored as normal, sprained or torn. The menisci, ligaments and tendons of each knee were also assessed. The mean age was 27.4 years (range, 9–69 years), and 71.5% (n = 143) of the patients were male. The anterolateral ligament (ALL) was graded as ruptured in 17 cases (8.5%), sprained in 58 cases (29%), normal in 116 cases (58%) and not visible in 9 cases (4.5%). Of cases with injury of the ALL (n = 75), there was associated injury of the anterior cruciate ligament (ACL) in 61 cases, medial collateral ligament (MCL) in 51 cases, popliteofibular ligament (PFL) in 29 cases, medial meniscus in 29 cases, lateral meniscus in 24 cases, lateral collateral ligament in 9 cases, posterior cruciate ligament in 8 cases, biceps femoris in 5 cases, popliteus tendon in 4 cases and fluid or oedema was seen adjacent to the iliotibial band in 59 cases. No cases of isolated ALL injury were seen. ALL injury is not uncommon in acute knee trauma and is typically associated with significant internal derangement of the knee, especially anterior cruciate ligament rupture, ITB sprain, medial collateral ligament injury, meniscal tears and injury to the popliteofibular ligament.

BackgroundThe aim of this study was to examine whether dynamic fluoroscopy is reliable for assessment of medial elbow stability in the presence of radial head resection and different stages of medial collateral ligament (MCL) dissection in a cadaveric elbow model.Materials and methodsSix intact elbow specimens were measured for joint angulation while applying valgus stress in four examination conditions (Examiner 1, Examiner 2, 1 Nm, 2 Nm) in four different elbow positions (fully pronated or supinated at 0° of elbow extension and 30° of elbow flexion). The elbow specimens were examined for valgus stress in three stages: (1) intact, (2) after radial head resection, and (3) after subsequent dissection of the complete MCL. Anteroposterior radiographs of the elbow were made at each stage to determine joint angulation. Intraclass correlation coefficients (ICCs) were calculated.ResultsIn intact elbows, mean joint angulation ranged from 2.2° ± 2.0 (1 Nm) to 5.2° ± 2.3 (Examiner 1). Radial head resection did not increase joint angulation during valgus stress, regardless of joint position and examination condition (Examiner 1: 5.5°; Examiner 2: 5.0°; 1 Nm: 2.6°, 2 Nm: 3.9°). Additional dissection of the MCL led to significantly higher joint angulation during measurements with the standardized torques (1 Nm: 12.4°; 2 Nm: 23.3°). Very good to excellent ICCs for joint angulation between Examiner 1 and Examiner 2 (0.861 to 0.959) were found.ConclusionDynamic fluoroscopy is a reliable diagnostic tool for determining medial elbow stability in the presence of radial head resection and different stages of MCL dissection.

Here we investigated the morphology, quantity, distribution and gene expression of mechanoreceptors in the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), lateral collateral ligament (LCL), patellar tendon (PaT) and popliteal tendon (PoT) of the knee joint. Twelve 6-month-old rabbits were divided into two groups. In one group, the ACL, PCL, MCL, LCL, PaT and PoT were collected to observe the morphology, distribution and quantity of mechanoreceptors. In another group, the ACL, PCL, MCL, LCL, PaT and PoT of bilateral knee joints were used to determine S100B, CGRP and NEFM gene levels. Five types of mechanoreceptors were observed including Ruffini corpuscles, Pacinian corpuscles, Golgi-tendon bodies, atypical mechanoreceptors and free nerve endings. The total amount of mechanoreceptors was significantly lower in MCL, LCL, PaT and PoT as compared with ACL and PCL (P 0.001). All examined mechanoreceptors were present in ACL, PCL and LCL. However, no Pacinian corpuscles and Golgi-tendon bodies were found in MCL and PoT as well as Pacinian corpuscles were not observed in PaT. The present study indicated that the levels of NEFM was significantly lower in PCL, MCL, LCL, PaT and PoT as compared with ACL (P 0.05), but there was no significant difference in CGRP level between ACL and other ligaments except LCL (P 0.05). Thus, the quantity, type and gene expression of mechanoreceptors are different in various ligaments. Thus, the quantity and distribution of mechanoreceptors may be related to ligament's function.

The purpose of this study was to evaluate and compare knee kinematics and kinetics following either single bundle, modified triangular or double-bundle reconstruction of the superficial medial collateral ligament (sMCL) with single bundle anatomic ACL reconstruction. Using a cadaveric model (n = 10), the knee kinematics and kinetics following three MCL reconstructions (single-bundle (SB), double-bundle (DB), modified triangular) with single bundle anatomic ACL reconstruction were compared with the intact and deficient knee state. The knees were tested under (1) an 89-N anterior tibial load, (2) 5 N-m internal and external rotational tibial torques, and (3) a 7 N-m valgus torque. Anatomic ACL reconstruction with SB MCL reconstruction was able to restore anterior tibial translation and external rotation to intact knee values but failed to the internal and valgus rotatory stability. Anatomical DB MCL reconstruction (with SB ACL reconstruction) and the modified triangular MCL reconstruction (with SB ACL reconstruction) restored all knee kinematics to the intact value. This study shows that clinical presentation with combined ACL and severe sMCL injury, single-bundle MCL with single-bundle ACL reconstruction does not restore knee kinematics. Anatomical double-bundle MCL reconstruction may produce slightly better biomechanical stability than the modified triangular MCL reconstruction, but the modified triangular reconstruction might be more clinically practical with the advantages of being less invasive and technically simpler while at the same time can restore a nearly normal knee joint.

Purpose Revision constrained-condylar total knee arthroplasty (CCK-TKA) is often used to provide additional mechanical constraint after failure of a primary TKA. However, it is unknown how much this translates to a reliance on soft-tissue support. The aim of this study was therefore to compare the laxity of a native knee to the CCK-TKA implanted state and quantify how medial soft-tissues stabilise the knee following CCK-TKA. Methods Ten intact cadaveric knees were tested in a robotic system at 0°, 30°, 60° and 90° flexion with ± 90 N anterior–posterior force, ± 8 Nm varus-valgus and ± 5 Nm internal–external torques. A fixed-bearing CCK-TKA was implanted and the laxity tests were repeated with the soft tissues intact and after sequential cutting. The deep and superficial medial collateral ligaments (dMCL, sMCL) and posteromedial capsule (PMC) were sequentially transected and the percentage contributions of each structure to restraining the applied loads were calculated. Results Implanting a CCK-TKA did not alter anterior–posterior laxity from that of the original native knee, but it significantly decreased internal–external and varus-valgus rotational laxity (p Conclusions With a fully-competent sMCL in-vitro, a fixed-bearing CCK-TKA knee provided more rotational constraint than the native knee. The robotic test data showed that both the soft-tissues and the semi-constrained implant restrained rotational knee laxity. Therefore, in clinical practice, a fixed-bearing CCK-TKA knee could be indicated for use in a knee with lax, less-competent medial soft tissues. Level of evidence Controlled laboratory study.

The purpose of this study was to examine the predictive value concerning clinical outcome and implant survival, as well as the accuracy of individual tests of a recently published radiographic decision aid for unicondylar knee arthroplasty indication findings. In the retrospective part of the study, 98 consecutive patients who had undergone unicondylar knee arthroplasty (Phase 3 Oxford medial UKA) were included, using revision questionnaires, as well as the Forgotten Joint Score-12 (FJS-12) and Knee Osteoarthritis Outcome Score (KOOS) and analysed for suitability of the radiographic decision aid. Inappropriate and appropriate indications were then compared concerning the clinical outcome and implant survival. The prospective part of the study assessed the accuracy of the decision aid's radiographic tests (varus and valgus stress views, true lateral view and skyline view), and included 90 patients. Definition as appropriate for UKA procedure included medial bone-on-bone situation in varus stress views, full-thickness lateral cartilage and functional medial collateral ligament in valgus stress views, functional anterior cruciate ligament (ACL) in true lateral views and absence of lateral facet osteoarthritis with bone loss in skyline views. Pre-operative radiographic assessment with respect to the decision aid was then compared with intraoperative articular conditions. The clinical outcome was analysed using non-parametric tests (Mann–Whitney U), and revision rates were compared using the Fisher’s exact test. Accuracy assessment included calculations of the sensitivity, specificity, negative predictive value and positive predictive value. A p value

According to current literature, 90% of knee ligament injuries involve the medial collateral ligament or the anterior cruciate ligament. In contrast to the medial collateral ligament, which regenerates relatively well, the anterior cruciate ligament demonstrates compromised healing. In the past, there were numerous studies in animal models that examined the healing process of these ligaments, and different explanations were established. Although the healing of these ligaments has been largely investigated and different theories exist, unanswered questions persist.Therefore, the aim of this article is 1) to review the different historical aspects of healing of the medial collateral ligament and present the theories for healing failure of the anterior cruciate ligament; 2) to examine the novel epiligament theory explaining the medial collateral ligament healing process and failure of anterior cruciate ligament healing; and 3) to discuss why the enveloping tissue microstructure of the aforementioned ligaments needs to be examined in future studies.We believe that knowledge of the novel epiligament theory will lead to a better understanding of the normal healing process for implementing optimal treatments, as well as a more holistic explanation for anterior cruciate ligament healing failure.

Background As an uncommon but severe complication, medial collateral ligament (MCL) injury in total knee arthroplasty (TKA) may be significantly under-recognized. We aimed to determine whether MCL injury influences postoperative outcomes of patients undergoing TKA. Methods Two independent reviewers searched PubMed, Cochrane Library, and EMBASE from their inception to July 1, 2021. The main outcomes were postoperative function, and secondary outcomes included the incidences of revision and complications. Results A total of 403 articles yielded 15 studies eligible for inclusion with 10 studies used for meta-analysis. This study found that there was a statistically significant difference in postoperative functional scores, range of motion (ROM), complications, and revision rates, with adverse outcomes occurring more commonly in patients with MCL injury. Conclusions This meta-analysis highlights the complexity of MCL injury during TKA and shows the impact on postoperative function, joint mobility, complications, and revision. Surgeons need to prevent and put more emphasis on MCL injury during TKA.

To analyze the MRI characteristics of distal superficial medial collateral ligament (sMCL) tears and to identify features of tears displaced superficial to the pes anserinus (Stener-like lesion (SLL)). Knee MRI examinations at four institutions were selected which showed tears of the sMCL located distal to the joint line. MRIs were evaluated for a SLL, a wavy contour to the sMCL, and the location of the proximal sMCL stump. Additional coexistent knee injuries were recorded. The study included 51 patients (mean age, 28 years [sd, 12]). A SLL was identified in 20 of 51 cases. The proximal stump margin was located significantly (p < 0.01) more distal and more medial with a SLL (mean = 33 mm [sd = 11 mm] and mean = 6.5 mm [sd = 2.5 mm], respectively), than without a SLL (mean = 19 mm [sd = 16 mm] and mean = 4.8 mm [sd = 2.4 mm], respectively). Medial compartment osseous injury was significantly (p < 0.05) more common with a SLL (75%) than without a SLL (42%). The frequency of concomitant injuries in the group (ACL tear, 82%; PCL tear, 22%; deep MCL tear, 61%; lateral compartment osseous injury, 94%) did not differ significantly between patients with and without a SLL. A distal sMCL tear should be considered when MRI depicts a wavy appearance of the sMCL. Distal sMCL tears have a frequent association with concomitant knee injuries, especially ACL tears and lateral femorotibial osseous injuries. A SLL is particularly important to recognize because of implications for treatment.

To biomechanically investigate the influence of osseous valgus alignment, with and without deficiency of the posteromedial ligament complex (PMC), on ACL-graft forces under axial load. ACL reconstruction was performed on ten cadaveric knee joints. A lateral distal femur osteotomy was then done to adjust for three different alignment conditions according to the position, where the axial weight bearing line (WBL) dissected the tibial plateau (% from medial to lateral): 50%, 85% and 115%. Each alignment was tested with the PMC intact, deficient and reconstructed. Axial loads of 400 N were applied in 15° of knee flexion and changes of ACL-graft forces and dynamic valgus angle (DVA) were recorded. In the PMC intact state, lateralization of the WBL to 85% and to 115% led to significantly increased ACL graft forces (85%: p = 0.010; 115%: p

The purpose of this study was to determine the ideal coronal alignment under dynamic conditions after open-wedge high tibial osteotomy (OWHTO). It was hypothesised that, although the classical target alignment was based on experimental evidence, it would demonstrate biomechanical validity. Musculoskeletal computer models were analysed with various degrees of coronal correction in OWHTO during gait and squat, specifically with the mechanical axis passing through points at 40%, 50%, 60%, 62.5%, 70%, and 80% of the tibial plateau from the medial edge, defined as the weight-bearing line percentage (WBL%). The peak load on the lateral tibiofemoral (TF) joint, the medial collateral ligament (MCL), and anterior cruciate ligament (ACL) tensions, and knee kinematics with or without increased posterior tibial slope (PTS) were evaluated. The classical alignment with WBL62.5% achieved sufficient load on the lateral TF joint and maintained normal knee kinematics after OWHTO. However, over-correction with WBL80% caused an excessive lateral load and non-physiological kinematics. Increased WBL% resulted in increased MCL tension due to lateral femoral movement against the tibia. With WBL80%, abnormal contact between the medial femoral condyle and the medial intercondylar eminence of the tibia occurred at knee extension. The screw-home movement around knee extension and the TF rotational angle during flexion were reduced as WBL% increased. Increased PTS was associated with increased ACL tension and decreased TF rotation angle because of ligamentous imbalance. The classical target alignment demonstrated validity in OWHTO, and over-correction should be avoided as it negatively impacts clinical outcome. IV.

Purpose: The aim of this study was to compare outcome data after isolated and combined (MCL) plus anterior cruciate ligament (ACL) reconstruction based on objective and subjective measures using data from the (DKRR). There are only a few small-sized case studies on outcomes after MCL reconstruction. MCL reconstruction was hypothesised to improve both objective and subjective outcomes. Methods: All patients who were registered in the DKRR between 2005 and 2016 (N = 25,281) and who underwent isolated ACL (n = 24,683), isolated MCL (n = 103) or combined MCL plus ACL (n = 495) reconstructions were retrospectively identified. Objective (valgus knee stability and sagittal knee laxity) and subjective (Knee Injury and Osteoarthritis Outcome Score (KOOS) and Tegner activity scale score) outcomes in these three cohorts were evaluated at the 1-year follow-up by comparing pre- and post-operative values. Results: Medial stability improved significantly pre- to post-operatively after both isolated MCL and combined MCL plus ACL reconstruction, with 26 (53%) and 195 (69%) of the patients, respectively, having normal valgus stability (0–2 mm laxity). Sagittal stability was similar after MCL plus ACL reconstruction and isolated ACL reconstruction (1.7 and 1.5 mm, respectively). At the 1-year follow-up, although the KOOS of the patients in the isolated MCL and combined MCL plus ACL reconstruction cohorts improved significantly, they were lower than those of the patients in the isolated ACL reconstruction cohort. Conclusion: Both isolated MCL reconstruction and combined MCL plus ACL reconstruction resulted in significant and clinically relevant improvements in the subjective outcomes from pre-operative conditions to the 1-year follow-up. Valgus stability also improved significantly, with two-thirds of patients obtaining normal valgus stability after MCL reconstruction. Subjective outcomes were similar between isolated MCL reconstruction and combined MCL plus ACL reconstructions, but were poorer than isolated ACL reconstructions. Level of evidence: Level III.

To evaluate the mid-term outcomes of anatomic medial complex reconstruction in cases of serious medial knee instability. Between 2010 and 2013, 23 patients who underwent anatomic medial complex reconstruction with a minimum 5-year follow-up were included. The Lysholm score, International Knee Documentation Committee subjective knee form (IKDC SKF), and Tegner activity scale scores were evaluated. Clinical and functional tests included valgus and sagittal stress tests, isokinetic muscle strength test, single leg hop for distance test (SLDT), and single leg vertical jump test (SLVT). The mean follow-up duration was 77.2 ± 10.8 months. At final follow-up, the Lysholm score improved from 49.7 ± 10.2 to 93.4 ± 12.4; the IKDC SKF score, from 46.2 ± 8.7 to 90.5 ± 13.9; and median Tegner activity, from 5 (4–7) to 7 (4–10) (P

The aim of this study was to evaluate a radiographic measurement method for assessment of overlengthening of the MoPyC radial head prosthesis. Seven cadaver specimens were studied in ten stages: native specimen (1), radial head resection (2), and implantation of the MoPyC radial head prostheses (Bioprofile, Tornier, Montbonnot-Saint-Martin, France) in four increasing length (correct length, overlengthening of 1.5 mm, 3 mm, and 5 mm) with an intact medial collateral ligament (MCL 3–6) and following transection of the MCL (7–10). The radiographic measurement method according to Athwal et al. was evaluated to detect overlengthening. Statistical analysis included calculation of the diagnostic accuracy of the radiographic method. The radiographic measurement method correctly determined the size of the radial head prosthesis within ± 1 mm in 224 of 336 scenarios (67%) and within ± 2 mm in 320 of 336 scenarios (95%). With a threshold value of ≥ 1 mm, the overall diagnostic sensitivity for detecting overlengthening when it was present and was 90% and the specificity was 79%. The sensitivity was higher with increasing size of the prosthesis: in cases with overlengthening of 1.5 mm, the sensitivity was 76%, with an overlengthening of 3 mm, the sensitivity was 95%, and with an overlengthening of 5 mm, the sensitivity was 100%. The radiographic measurement method of Athwal et al. can be used to estimate and to diagnose the magnitude overlengthening of the MoPyC radial head prosthesis. However, the sensitivity is limited (76%) in cases with a small amount of overlengthening of 1.5 mm.

Arthroscopic release for the stiff elbow has been widely used, but there are no reports limited to severe stiffness. The purpose of this study was to investigate the outcomes of severe cases. Ten patients with 10 severely stiff elbows defined by a limited arc of ≤ 60° underwent this arthroscopic release. Causes of stiffness were post-traumatic stiffness (one patient), osteoarthritis (three patients), and rheumatoid arthritis (six patients). Using arthroscopy, the capsule contracture and the intra-articular fibrosis were removed and the impinging osteophyte and part of the radial head were resected. For four patients with preoperative ulnar nerve symptoms or contracture of the posterior oblique ligament of the medial collateral ligament, mini-open ulnar nerve neurolysis and release of the posterior oblique ligament were performed. Patients were followed up for an average of 24 months. Arthroscopic release could be performed without any intraoperative complications. Range of motion for the elbow significantly improved from 95° of flexion and − 55° of extension to 109° of flexion and − 32° of extension. The Mayo Elbow Performance Score also improved from 56 points to 80 points. Two patients underwent a second arthroscopic surgery and gained further arc of motion. One patient showed osteophyte reformation and needed revision open surgery 1 year after the initial surgery. Arthroscopic release for the severely stiff elbow could improve range of motion. Careful attention should be given during surgery to avoid complications such as intramuscular bleeding or nerve damage.

The goal of this study was to evaluate the anatomy of the medial patellar retinaculum and the medial patellofemoral ligament (MPFL) to provide an anatomical validation of a pediatric reconstruction technique. Fifteen knees were dissected to study the MPFL and its relationship with the medial patellar retinaculum and the femoral insertion of the medial collateral ligament (MCL). The distances between the insertions of the MPFL of eight knees, and the patellar insertion of the MPFL and the femoral insertion of the MCL of four knees, were measured during the flexion to evaluate the isometricity of the native and reconstructed MPFL. The medial patellar retinaculum includes four structures: the fascia, fibrous expansions of the vastus muscles, the MPFL and the medial patellomeniscal ligament. The femoral insertion of the MPFL was located just behind the femoral insertion of the MCL in 12 knees. During flexion, the distance between the insertion on the upper patella and the femoral insertion of the MPFL increased while the distance between the insertion on the lower patella and the femoral insertion of the MPFL decreased. The variation in the distances measured during the flexion was greater between the MPFL insertions (nsup = 6.5 mm, ninf = 6.5 mm) than between the patellar insertion of the MPFL and the femoral insertion of the MCL (n′sup = 2.5 mm, n′inf = 5.75 mm). The MPFL is not isometric. Even though the results were obtained from knees of elderly specimens, this study demonstrates reconstruction of the MPFL should take into account its anatomy and biomechanical role in the knee.

Purpose In anterior cruciate ligament (ACL) injuries, concomitant damage to peripheral soft tissues is associated with increased rotatory instability of the knee. The purpose of this study was to investigate the incidence and patterns of medial collateral ligament complex injuries in patients with clinically ‘isolated’ ACL ruptures. Methods Patients who underwent ACL reconstruction for complete ‘presumed isolated’ ACL rupture between 2015 and 2019 were retrospectively included in this study. Patient’s characteristics and intraoperative findings were retrieved from clinical and surgical documentation. Preoperative MRIs were evaluated and the grade and location of injuries to the superficial MCL (sMCL), dMCL and the posterior oblique ligament (POL) recorded. All patients were clinically assessed under anaesthesia with standard ligament laxity tests. Results Hundred patients with a mean age of 22.3 ± 4.9 years were included. The incidence of concomitant MCL complex injuries was 67%. sMCL injuries occurred in 62%, dMCL in 31% and POL in 11% with various injury patterns. A dMCL injury was significantly associated with MRI grade II sMCL injuries, medial meniscus ‘ramp’ lesions seen at surgery and bone oedema at the medial femoral condyle (MFC) adjacent to the dMCL attachment site (p p p p Conclusion The incidence of combined ACL and medial ligament complex injuries is high. Lesions of the dMCL were associated with ramp lesions, MFC bone oedema close to the dMCL attachment, and sMCL injury. Missed AMRI is a risk factor for ACL graft failure from overload and, hence, oedema in the MCL (especially dMCL) demands careful assessment for AMRI, even in the knee lacking excess valgus laxity. This study provides information about specific MCL injury patterns including the dMCL in ACL ruptures and will allow surgeons to initiate individualised treatment. Level of evidence III.

Background We investigate the safety of the application of the Rigidfix cross-pin system via different tibial tunnels in the tibial fixation during anterior cruciate ligament (ACL) reconstruction. Methods Five adult fresh cadaver knees were fixed with the Rigidfix cross-pins in the tibial fixation site during ACL reconstruction. Two different tibial tunnel groups were established: in group A, the tunnel external aperture was placed at the 25° angle of coronal section; in group B, the tunnel external aperture was placed at the 45° angle of coronal section. The guide was placed at the plane 0.5 mm below articular facet through the tibial tunnel, with three rotation positions set at 0°, 30°, and 60° slopes. The incidences of iatrogenic injuries at tibial plateau cartilage (TPC), medial collateral ligament (MCL), and patellar tendon in three different slope angles were calculated in groups A and B and the results were analyzed by using chi square test. Results The iatrogenic injuries at MCL, TPC, and patellar tendon could occur after the Rigidfix cross-pin system was placed 5 mm below tibial plateau cartilage for ACL reconstruction. The incidences of TPC injury (χ2 = 5.662, P = 0.017) and MCL injury (P = 0.048, Fisher exact probability method) were significantly lower in group A than in group B. However, the incidence of patellar tendon injury showed no significant difference between these two groups (χ2 = 0.120, P = 0.729). Conclusions When the Rigidfix cross-pin system is used for ACL reconstruction at the tibial fixation site, the external aperture of tibial tunnel should not be placed at the excessively posterosuperior site, to avoid MCL and TPC injuries.

Purpose This study evaluated the medial joint stability after high tibial osteotomy (HTO) releasing the superficial medial collateral ligament (sMCL) without cutting and repairing. Methods Twenty-one patients who performed HTO were enrolled. After an L-shaped incision was made in the pes anserinus, the sMCL was released from the distal portion during surgery. After plate fixation, the sMCL was reattached and the pes anserinus was repaired underneath the plate. Plate removal was performed after 31.1 ± 14.2 months. Before HTO, a valgus force of 40 N was exerted at extension for reference values. Before and after plate removal, a valgus force of 40 N was exerted at extension and at a flexion position of 20°. Medial stability was evaluated by measuring the joint line convergence angle (JLCA). Results The JLCAs in the extension state before HTO and plate removal were 1.64° ± 1.15° and 1.83° ± 1.36°, respectively; there was no significant difference (p = 0.198). There was also no significant difference in JLCA before HTO and after plate removal (p = 0.835). There was also no significant difference in JLCA before and after plate removal both at a knee extension and flexion position of 20° (p = 0.348 and p = 0.456, respectively). Conclusions Releasing the sMCL without cutting and repairing the pes anserinus underneath the plate during medial open wedge HTO could facilitate the maintenance of medial joint stability.

BackgroundFew studies compared the length change of ligaments of normal knees during dynamic activities of daily living. The aim of this study was to investigate in vivo length change of ligaments of the normal knees during high flexion.MethodsEight normal knees were investigated. Each volunteer performed squatting, kneeling, and cross-leg motions. Each sequential motion was performed under fluoroscopic surveillance in the sagittal plane. The femoral, tibial, and fibular attachment areas of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), deep medial collateral ligament (dMCL), superficial medial collateral ligament (sMCL), and lateral collateral ligament (LCL) were determined according to osseous landmarks. After 2D/3D registration, the direct distance from the femoral attachment to the tibial or fibular attachment was measured as the ligament length.ResultsFrom 20° to 90° with flexion, the ACL was significantly shorter during cross-leg motion than during squatting. For the PCL, dMCL, sMCL, and LCL, there were no significant differences among the 3 motions.ConclusionThe ACL was shorter during cross-leg motion than during squatting in mid-flexion. This suggests that the ACL is looser during cross-leg motion than during squatting. On the other hand, the length change of the PCL, MCL, and LCL did not change even though the high flexion motions were different.

Das mediale Kollateralband, bestehend aus oberflachlichen und tiefen Bandanteilen, in Kombination mit dem Pfannenband ist der primare Stabilisator im Sprunggelenk. Verletzungen dieser Strukturen sind haufiger als bisher angenommen und werden oft ubersehen. In der Folge kann es zu chronischen Schmerzen, Instabilitaten, Ruckfusdeformitaten und Arthrosen kommen. Anamnese und klinische Untersuchung konnen Hinweise auf Verletzungen des medialen Kollateralbands liefern. Die Magnetresonanztomographie (MRT) gilt als Diagnostik der Wahl. Die Arthroskopie des oberen Sprunggelenks kann zusatzlich wertvolle Hinweise bei der Beurteilung der Verletzung bieten. Die Therapie sollte begleitende Verletzungen und Deformitaten einschliesen und reicht von einer Ruhigstellung im Gips uber eine Bandnaht bis hin zur Bandrekonstruktion mithilfe eines freies Sehnentransplantats.

Little effort has been directed towards the consequence of an injury on joint angular velocity. We hypothesized that the magnitude of knee joint angular velocity would be decreased after injury. Four injury groups were investigated in an ovine model: (1) anterior cruciate ligament (ACL) and medial collateral ligament (MCL) transection (ACL/MCL Tx) (n = 5), (2) lateral meniscectomy (Mx) (n = 5), (3) partial ACL transection (p-ACL Tx) (n = 5), and (4) partial-ACL and MCL transection (p-ACL/MCL Tx) (n = 5). The magnitude of the angular velocities decreased in the subjects of all groups at multiple points of the gait cycle. The maximum angular velocities during stance and the maximum extension angular velocities during swing were decreased in 15/20 and 17/20 subjects, respectively. There were strong correlations between morphological osteoarthritis scores and the reduction in the maximum extension angular velocities during swing 40 weeks post-p-ACL Tx and 20 weeks post-ACL/MCL Tx. There was no correlation between the decrease of the angular velocity and morphological osteoarthritis scores in the Mx group and the p-ACL/MCL Tx group. The reduction in angular velocity may be a helpful addition as a surrogate measure of OA risk after ACL injury, and could have clinical significance after further investigation in humans.

Total knee arthroplasty (TKA) for valgus knee osteoarthritis is challenging. Although overcorrection in TKA for valgus knee osteoarthritis is recommended, supportive data based on biomechanics have rarely been reported. The purpose of this study was to elucidate whether coronal rotation of the femoral compartment causes abnormal kinematics with or without medial looseness. Multi- and single-radius posterior-stabilised TKA implants were utilised in a computer simulation. A total of 4 mm of slack were provided in the medial collateral ligament (MCL) with varus or valgus position of the femoral component to simulate the context of valgus knee osteoarthritis. Kinematics during gait and squatting activities were evaluated in each condition. During squatting, medial looseness and valgus replacement caused anterior translation of the medial femoral component in mid-flexion in the multi-radius implant. In the worst condition (7° valgus replacement with MCL looseness), there was rapid anterior translation in the multi-radius implant, and moderate anterior translation in the single-radius implant. Although medial looseness alone did not cause abnormal kinematics during gait, the worst condition exhibited an anterior translation to 4.9 mm in the multi-radius implant. This worst condition also exhibited a marked lift-off of 8.0 and 2.9 mm in the multi- and single-radius implants, respectively. Varus position caused little abnormal kinematics even with MCL looseness. Valgus, not varus position of the femoral component caused abnormal kinematics with MCL looseness. To avoid valgus position, the safety target angle of femoral component would be slight varus rather than neutral in valgus knee OA.

Purpose To determine how concomitant medial collateral ligament (MCL) and lateral collateral ligament (LCL) injuries affect outcome after anterior cruciate ligament (ACL) reconstruction. Methods Patients aged > 15 years who were registered in the Swedish National Knee Ligament Registry for primary ACL reconstruction between 2005 and 2016 were eligible for inclusion. Patients with a concomitant MCL or LCL injury were stratified according to collateral ligament treatment (non-surgical, repair or reconstruction), and one isolated ACL reconstruction group was created. The outcomes were ACL revision and the 2-year Knee Injury and Osteoarthritis Outcome Score (KOOS), which were analyzed using univariable and multivariable Cox regression and an analysis of covariance, respectively. Results A total of 19,457 patients (mean age 27.9 years, 59.4% males) met the inclusion criteria. An isolated ACL reconstruction implied a lower risk of ACL revision compared with presence of a non-surgically treated MCL injury (HR = 0.61 [95% CI 0.41–0.89], p = 0.0097) but not compared with MCL repair or reconstruction. A concomitant LCL injury did not impact the risk of ACL revision. Patients with a concomitant MCL or LCL injury reported inferior 2-year KOOS compared with isolated ACL reconstruction. The largest difference was found in the sports and recreation subscale across all groups, with MCL reconstruction resulting in the maximum difference (14.1 points [95% CI 4.3–23.9], p = 0.005). Conclusion Non-surgical treatment of a concomitant MCL injury in the setting of an ACL reconstruction may increase the risk of ACL revision. However, surgical treatment of the MCL injury was associated with a worse two-year patient-reported knee function. A concomitant LCL injury does not impact the risk of ACL revision compared with an isolated ACL reconstruction. Level of evidence Cohort study, Level III.

To evaluate the usefulness of a novel MRI sequence strategy in the assessment of the periprosthetic anatomical structures after primary total knee arthroplasty. Two MR sequences were retrospectively compared for the imaging of 15 patients with implanted cruciate-retaining/fixed-bearing TKAs (DePuy, PFC Sigma): a slice encoding sequence for metal artifact correction (SEMAC) and a standard sequence. Images were acquired on a 1.5-T system. The degree of artifact reduction was assessed using several qualitative (Likert-type scale) (artifact size, distorsion, blur, image quality, periprosthetic bone, posterior cruciate ligament, lateral collateral ligament, medial collateral ligament, patella tendon, popliteal vessels) and quantitative (artifact volume, Insall–Salvati index, length of patella/tendon, prosthesis dimensions) parameters by blinded reads performed by four investigators. The SEMAC sequences were statistically compared with the standard sequence using Wilcoxon test. Additionally, the intraclass correlation coefficient (ICC) for interobserver agreement was calculated. Higher levels of blurring were found with SEMAC compared to standard sequences (p