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Background Sternoclavicular joint injections are one of the first-line treatment options for painful non-infectious pathologies of the sternoclavicular joint; however, their long-term effects and predictive value in decision-making for surgery are yet to be defined. Methods 27/32 Patients who received in total 36 computed tomography-guided sternoclavicular joint injections in 2012–2017 replied the questionnaire with a mean follow-up of 38 months after the first sternoclavicular joint injection. Of those patients, seven underwent subsequent surgery. We evaluated pain response after sternoclavicular joint injection and American Shoulder and Elbow Surgeons-score at later follow-up. Results Directly after sternoclavicular joint injection, pain decreased from Visual Analog Scale 5.3 ± 2.4 to 3.8 ± 3 (p = 0.001). In the seven patients who underwent surgery for degenerative changes, definitive outcome correlated with pain relief after the last infiltration (r = 0.86, p = 0.012). Also, the final American Shoulder and Elbow Surgeons-score was lower in patients with multiple injections compared to those who were satisfied after the first injection (p = 0.019). Discussion Sternoclavicular injections are a useful tool in the context of degenerative sternoclavicular joint disorders as the amount of pain reduction is, in case the short-term effect is not long-lasting, at least a strong indicator for the future success of operative treatment.

Background The treatment of unstable (Neer type IIB and V) extra-articular distal clavicle fractures remains challenging, especially when encountering a small lateral fragment which does not allow for sufficient screw purchase. It was the purpose of this study to present the clinical and radiologic outcome of a consecutive series of patients treated by a stand-alone coracoclavicular stabilization using a so-called cow-hitch technique with a suture anchor. Methods Nineteen patients were treated with a specific surgical technique for distal clavicle fractures (11 left, 8 right) with either rupture or bony avulsion of the coracoclavicular ligaments. Fourteen patients were examined in our outpatient clinic for the purpose of this study after a mean follow-up of 5 years (1-12.2 years). The examination included scoring according to Constant Murley score (CMS), the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), the Subjective Shoulder Value (SSV), and follow-up radiographs. Two additional patients were amenable to a telephone interview. Results All patients reported very good subjective results, with a mean SSV of 92% and a mean ASES score of 96%. The CMS resulted in average absolute values of 92 points. Fractures consolidated in 95% of cases. One patient developed an asymptomatic pseudarthrosis. The coracoclavicular distance was restored from 21 mm preoperatively to 11 mm at the final follow-up and finally showed an average side-to-side difference of +1.8 mm. Sports activities were fully resumed after an average of 4.7 months. Conclusion The coracoclavicular stand-alone cow-hitch suture repair for unstable distal clavicle fractures is a minimally invasive fixation technique without prominent hardware that allows for an anatomic reduction and stable fixation with a low complication and high bony union rate. Both radiographic and clinical long-term results are very satisfactory.

Background: In a sheep rotator cuff model, tenotomy predominantly induces fatty infiltration, and denervation induces mostly muscle atrophy. In clinical practice, myotendinous retraction after tendon tear or lateralization after tendon repair tear may lead to traction injury of the nerve. Purpose/Hypothesis: To analyze whether an additional nerve lesion during rotator cuff repair leads to further degeneration of the rotator cuff muscle in the clinical setting. We hypothesized that neurectomy after tendon tear would increase atrophy as well as fatty infiltration and that muscle paralysis after neurectomy would prevent myotendinous retraction after secondary tendon release. Study Design: Controlled laboratory study. Methods: Twelve Swiss alpine sheep were used for this study. For the 6 sheep in the tenotomy/neurectomy (T/N) group, the infraspinatus tendon was released; 8 weeks later, the suprascapular nerve was transected. For the 6 sheep in the neurectomy/tenotomy (N/T) group, neurectomy was performed, and the infraspinatus was tenotomized 8 weeks later. All sheep were sacrificed after 16 weeks. Magnetic resonance imaging (MRI) was performed before the first surgery (baseline) and then after 8 and 16 weeks. The MRI data were used to assess muscle volume, fat fraction, musculotendinous retraction, pennation angle, and muscle fiber length of the infraspinatus muscle. Results: Three sheep (2 in the T/N and 1 in the N/T group) had to be excluded because the neurectomy was incomplete. After 8 weeks, muscle volume decreased significantly less in the T/N group (73% ± 2% of initial volume vs 52% ± 7% in the N/T group; P < .001). After 16 weeks, the mean intramuscular fat increase was higher in the T/N group (36% ± 9%) than in the N/T group (23% ± 6%), without reaching significance (P = .060). After 16 weeks, the muscle volumes of the N/T (52% ± 8%) and T/N (49% ± 3%) groups were the same (P = .732). Conclusion: Secondary neurectomy after tenotomy of a musculotendinous unit increases muscle atrophy. Tenotomy of a denervated muscle is associated with substantial myotendinous retraction but not with an increase of fatty infiltration to the level of the tenotomy first group. Clinical Relevance: Substantial retraction, which is associated with hitherto irrecoverable fatty infiltration, should be prevented, and additional neurogenic injury during repair should be avoided to limit the development of further atrophy., Orthopaedic Journal of Sports Medicine, 9 (8), ISSN:2325-9671

BackgroundOptimal radii of curvature of the articulating surfaces of the prosthetic components are factors associated with the longevity of cemented glenoid components in anatomical total shoulder arthroplasty. It was the purpose of this study, to evaluate the radiographic and clinical performance of an anatomical glenoid component of a total shoulder arthroplasty (TSA) with respect to radial mismatch of the glenoid and humeral component.MethodsIn a retrospective study 75 TSA were analyzed for their clinical and radiographic performance with computed tomography by independent examiners using an established methodology. The study group was divided in two groups, one with mismatch ResultsThe mean glenohumeral radial mismatch was 3.4 mm (range 0.5–6.9). At median follow-up of 41 months (range 19–113) radiographic loosening (defined as modified Molé scores ≥6) was present in 7 cases (9.3%). Lucencies around the glenoid pegs (defined as modified Molé score ≥ 1) were present in 34 cases (45%). Radiolucencies were significantly associated with a radial mismatch p = 0.000). The pre- to postoperative improvements in Subjective Shoulder Value and absolute Constant Score were significantly better in the group with a mismatch ≥4.5 mm (p = 0.018,p = 0.014).ConclusionA lower conformity of the radii of humerus and glenoid seems to improve the loosening performance in TSA. Perhaps cut-off values regarding the recommended mismatch need to be revalued in the future.

Background Portal placement is a key factor for the success of arthroscopic procedures, particularly in rotator cuff repair. We hypothesize that the acromial anatomy may strongly determine the position of the shoulder bony landmarks and limit the surgeon’s freedom to position the arthroscopic approaches in direction towards the acromion. The purpose of this study was to analyze the relation between different acromial shapes and the freedom of movement of arthroscopic instruments relative to the rotator cuff from standardized arthroscopic portals in a laboratory study on 3D shoulder models. Methods 3D models of shoulders with a broad range of different acromial shapes were printed using CT and MRI scans. Angles from the portals to defined points on the rotator cuff and the supraglenoid tubercle were measured. In conventional radiographs, the critical shoulder angle, the scapular body acromial angle, and the glenoid acromial angle were measured and compared with the measured angles to the rotator cuff. Results There was a large variation of angles of approach of instruments to the rotator cuff between the seven shoulders for each portal. From the joint line portal and the posterior edge portal, the biggest angles were measured to the posterior cuff. From the intermediate portal, the angles were largest to the intermediate rotator cuff and from the anterior portals to the anterior cuff. To the supraglenoid tubercle, best access was from anterior. For all portals, there was a big correlation between the glenoid acromial angle and the scapular body acromial angle with the angles of approach to the tendon and especially to the supraglenoid tubercle. Conclusion The access to the rotator cuff from almost every portal is influenced by the acromial shape. As hypothesized, a small (small GAA) and flat (big SBAA) acromion provide an easier approach to the rotator cuff from almost every portal. Therefore, it may severely influence the instruments maneuverability.

Background Most studies demonstrated, that training on a virtual reality based arthroscopy simulator leads to an improvement of technical skills in orthopaedic surgery. However, how long and what kind of training is optimal for young residents is unknown. In this study we tested the efficacy of a standardized, competency based training protocol on a validated virtual reality based knee- and shoulder arthroscopy simulator. Methods Twenty residents and five experts in arthroscopy were included. All participants performed a test including knee -and shoulder arthroscopy tasks on a virtual reality knee- and shoulder arthroscopy simulator. The residents had to complete a competency based training program. Thereafter, the previously completed test was retaken. We evaluated the metric data of the simulator using a z-score and the Arthroscopic Surgery Skill Evaluation Tool (ASSET) to assess training effects in residents and performance levels in experts. Results The residents significantly improved from pre- to post training in the overall z-score: − 9.82 (range, − 20.35 to − 1.64) to − 2.61 (range, − 6.25 to 1.5); p

Immobilization, using a shoulder abduction brace, may be important after rotator cuff repair to achieve successful tendon-to-bone healing. Compliance with wear time is a concern.Therefore, the abduction brace wearing time was assessed with temperature-sensitive sensors to objectively measure the abduction brace wearing compliance rate.Level of evidence I, prospective observational study.A temperature sensor was implanted into 54 standard shoulder abduction braces, worn by 50 patients (27 women; mean age, 56 years). At 6 weeks post-surgery, patients reported the number of hours they had worn the brace. The patient-reported and sensor data were compared, and the compliance rate (relative to the recommended wearing time) was determined, with compliance being the primary end-point and the discrepancy between the measured and patient-reported wear time being the secondary end-point.Compliance was ⩾80% in 24 (48%) patients. Sensor-based compliance was lower than self-reported compliance (75% versus 96%, p ⩽ 0.001). Compliance was not predicted by age, sex, smoking, educational, employment, living status, or handedness.Roughly 50% of patients did not wear the brace at least 80% of the recommended time. Self-reported compliance is significantly lower than sensor-based compliance. Compliance was not predicted by measured demographic variables.This is the first study in which the abduction brace adherence of patients after rotator cuff repair was assessed by the use of a temperature-sensitive sensor. The postoperative use of these braces is questionable as the patient's abduction brace adherence is low. The self-reported wearing compliance is unreliable.

Clinical presentation of left ventricular non-compaction cardiomyopathy (LVNC) can be heterogeneous from asymptomatic expression to congestive heart failure. Deformation indices assessed by cardiovascular magnetic resonance (CMR) can determine subclinical alterations of myocardial function and have been reported to be more sensitive to functional changes than ejection fraction. The objective of the present study was to investigate the determinants of myocardial deformation indices in patients with LVNC. Twenty patients with LVNC (44.7 ± 14.0 years) and twenty age- and gender-matched controls (49.1 ± 12.4 years) underwent functional CMR imaging using an ECG-triggered steady state-free-precession sequence (SSFP). Deformation indices derived with a feature tracking algorithm were calculated including end-systolic global longitudinal strain (GLS), circumferential strain (GCS), longitudinal and circumferential strain rate (SRll and SRcc). Twist and rotation were determined using an in-house developed post-processing pipeline. Global deformation indices (GLS, GCS, SRll and SRcc) were significantly lower in patients with LVNC compared to healthy controls (all, p, Scientific Reports, 9 (1), ISSN:2045-2322

BACKGROUND Anatomic factors associated with static posterior translation of the humeral head with or without glenohumeral osteoarthritis are unknown. We tested the hypothesis that there is an association between glenoid wear, glenoid version, and/or anteroposterior acromial tilt. METHODS Ninety-nine patients with glenohumeral joint degeneration involving advanced glenoid cartilage wear and/or rotator cuff disease scheduled for anatomic or reverse total shoulder replacement underwent standardized conventional radiographic and computed tomographic shoulder imaging. Measurements included glenoid version, humeral torsion, posterior acromial slope, and critical shoulder angle. The glenoid shape was classified according to Walch et al, and the integrity of the rotator cuff was assessed. RESULTS Patients with glenoid type B2 or C had a median of 4° more glenoid retroversion (P = .022), a 5° less steep acromion (posterior acromial slope, 61° vs 56°; P = .004), and a higher combined score (glenoid version minus slope; odds ratio, 0.93 [95% confidence interval, 0.89-0.97]; P

BACKGROUND The pathomechanisms of eccentric osteoarthritis of the shoulder remain unclear. Although there is increasing evidence of bony differences between shoulders with rotator cuff tears and osteoarthritis, analogous differences have not been identified for primary concentric and eccentric osteoarthritis. This study examined the shape and orientation of the acromial roof as a potential risk factor for the development of posterior glenoid wear. METHODS We analyzed computed tomography images of 105 shoulders with primary osteoarthritis. Based on the classification of Walch, 45 shoulders had concentric osteoarthritis (Walch A) and 60 shoulders were affected by eccentric osteoarthritis (Walch B; EOA). A comparison of acromial morphology was performed in a multiplanar reconstruction analysis of computed tomography scans. RESULTS Acromial shape: Acromial length, width, and area were not significantly different. Acromial roof orientation: The acromial roof in EOA was an average of 5° flatter (sagittal tilt; P

Background There is evidence for differences of scapular shape between shoulders with rotator cuff tears (RCT) and osteoarthritic shoulders (OA). This study analyzed orientation and shape of the acromion in patients with massive RCT and concentric OA (COA) in a multiplanar computed tomography (CT) analysis. Methods CT scans of 70 shoulders with degenerative RCT and 45 shoulders with COA undergoing primary shoulder arthroplasty were analyzed. The 2 groups were compared in relation of (1) shape of the acromion, (2) its orientation in space, and (3) the anteroposterior glenoid coverage in relation to the scapular plane. Results Lateral acromial roof extension was an average of 4.6 mm wider and the acromial area was an average of 156 mm2 larger in RCT than in COA (P Conclusions A more externally rotated (axial plane), more downward tilted (coronal plane), and wider posterior covering acromion was more frequent in patients with massive RCT than COA.

BACKGROUND The treatment of periprosthetic joint infection (PJI) of the shoulder with two-stage revision arthroplasty using an antibiotic-loaded cement spacer is established strategy, but there is sparse information regarding the likelihood of infection control and restoration of shoulder. QUESTIONS/PURPOSE (1) What is the likelihood of infection control after two-stage revision using an antibiotic cement spacer for patients with PJI of the shoulder? (2) What are the improvements in Constant and Murley scores at 2 years after these staged revisions? PATIENTS AND METHODS Between 2000 and 2013, we treated 48 patients with PJI of the shoulder using two-stage revision including an antibiotic-containing cement spacer during the first stage. Of those, 38 (79%) were available for review at a minimum of 24 months (mean, 52 ± 34 months). Ten patients (21%) were excluded because they were deceased (n = 3), moved abroad (n = 4), or refused followup (n = 3), leaving 38 for analysis in this retrospective study. During the first stage, removal of the prosthesis, debridement, and implantation of a gentamicin and vancomycin-filled cement spacer were performed by four different surgeons followed by antibiotic therapy (2 weeks intravenous plus 10 weeks oral). For the second stage, we generally tried a reverse total shoulder arthroplasty (RTSA; n = 26). In case of severe glenoid destruction, hemiarthroplasty (HA; n = 8) was used as a salvage option. In 14 patients the cement spacer was left in place because the patients refused further surgery or were not operable owing to medical reasons. The primary outcome included the proportion of patients achieving infection control 2 years after the second-stage procedure after implantation of the cement spacer. Infection control was determined as the absence of the Musculoskeletal Infection Society PJI criteria. The clinical outcome assessed with the Constant and Murley scores served as the secondary outcome parameter. A subgroup (RTSA; HA, spacer retention) analysis of the Constant and Murley scores was performed. RESULTS Successful infection control was achieved in 36 of 38 patients (95%). Patients who underwent treatment with a cement spacer had increased Constant and Murley scores at latest followup compared with their pretreatment scores (mean ± SD, 27 ± 19 versus 43 ± 20; mean difference, 17; 95% CI, 10-24; p = 0.001). For patients who underwent staged treatment followed by second-stage RTSA (n = 23), the Constant and Murley scores increased (mean ± SD, 31 ± 20 versus 51 ± 20; mean difference, 20; 95% CI, 11-30; p = 0.001). The Constant and Murley scores did not improve in patients who underwent HA (mean ± SD, 22 ±15 versus 24 ± 90; mean difference, 3; 95% CI, -10 to 16; p = 0.509) or who retained the spacer (mean ± SD, 18 ±12 versus 35 ±10; mean difference, 19; 95% CI, -5 to 44; p = 0.093). CONCLUSION Revision arthroplasty using an antibiotic-loaded cement spacer provided successful infection control in patients with periprosthetic shoulder infections in this small, retrospective series. Functional improvement was obtained after reimplantation of a reverse total shoulder prosthesis but was not seen after HA and cement spacer; however, baseline differences among patient groups very likely contributed to these differences, and they should not be attributed to implant selection alone. LEVEL OF EVIDENCE Level III, therapeutic study.

Background Open reduction and internal fixation (ORIF) of complex fractures of the proximal humerus may yield unsatisfactory results. This study analyzed the results obtained after revision of failed ORIF of proximal humeral fractures using reverse total shoulder arthroplasty (RTSA). Methods Fifty-four shoulders of 53 patients with a subjectively unacceptable outcome after ORIF of a complex fracture of the proximal humerus were revised with RTSA. At a minimum follow-up of 2 years (mean follow-up, 46 months; range, 24-108 months), 44 shoulders were clinically and radiographically reviewed for the purpose of this study. Six patients had been lost to follow-up, and 4 patients (7%) were excluded from functional analysis because of revision surgeries. Results The mean absolute Constant score improved from 26 (range, 4-54) to 55 (range, 19-80) points; the mean relative Constant score improved from 32% (range, 4%-85%) to 67% (range, 27%-94%) of an age- and gender-matched, normal shoulder. The mean subjective shoulder value improved from 29% (range, 0%-90%) preoperatively to 67% (range, 5%-95%) at final follow-up. Nineteen patients rated their outcome excellent, 16 good, and 7 fair; 2 patients were dissatisfied. Conclusion RTSA is a valuable salvage procedure after failed ORIF of a proximal humeral fracture with relatively low revision rates. Shoulder function, patient satisfaction, and pain levels can be reliably improved.

Purpose: Chronic tearing of tendons is associated with molecular and structural alterations causing biomechanical changes, which compromise musculotendinous function and become limiting factors for tendon repair. This study investigated the histological response of chronically retracted sheep rotator cuff tendons to mechanical and pharmacological stimulation in view of tendon repair. Methods: Sixteen weeks after experimental release of the infraspinatus tendon in 20 sheep, the retracted musculotendinous unit was subjected to continuous traction either with [anabolic steroids (nandrolone) group/insulin-like growth factor (IGF) group] or without (control group) additional pharmacological treatment during 6weeks. A new degeneration score for tendinous tissues (DSTT), based on established knowledge on histological changes associated with tendon degeneration, was used for histological analysis at the time of tendon release, at the beginning of continuous re-lengthening and at repair in all animals. Results: The DSTT score (inter-observer correlation: r=0.83), quantifiably representing tendon degeneration, improved from 15.5 (SD 1.3) points before to 9.8 (SD 3.8) points after re-lengthening. It improved in a qualitatively and quantitatively similar fashion if pharmacological stimulation was added. The nandrolone group improved from 13.7 (SD 1.6) to 9.8 (SD 1.9) and the IGF group from 13.3 (SD 3.6) to 8.8 (SD 1.8) points. Conclusion: Mechanical stimulation significantly reduced tissue degeneration. However, the addition of a pharmacological stimulation with anabolic steroids or IGF had neither a measurable positive nor negative effect on the degenerative process. Therefore, this investigation does neither support the additional pharmacological use of the anabolic steroid nandrolone or of IGF decanoate for restoration of tendon degeneration, nor otherwise provide evidence for additional tendon damage, if those substances are used to alter the muscular metabolism.

Background It was the purpose of this paper to analyze structural, functional, and electrophysiologic variables that may determine preserved overhead function for patients with massive rotator cuff tears. Methods Nineteen patients (20 shoulders) were prospectively included in either the pseudoparalytic (n = 9) or the non-pseudoparalytic group (n = 11). Fatty infiltration was graded according to Goutallier, and anterior (subscapularis) and posterior (infraspinatus and teres minor) tear extension was graded 0 (no involvement) to 4 (full tear) on magnetic resonance imaging. Glenohumeral and scapulothoracic rhythm was assessed by fluoroscopic motion analysis, and electromyographic evaluation of the deltoid muscle was performed. Results We found no significant difference of fatty infiltration of the supraspinatus (3.9 vs 3.6), infraspinatus (3.9 vs 3.8), and teres minor (1.7 vs 0.6) or of the posterior tear extension (2.6 vs 2.0) between pseudoparalytic and non-pseudoparalytic shoulders. Global tear extension in the parasagittal plane (205° vs 163°) and subscapularis involvement (2.6 vs 1.2), however, showed significant differences between the two groups, and no patient with a full-thickness supraspinatus and infraspinatus tear with extension into the inferior half of the subscapularis was able to lift the arm to 90°. Fluoroscopic assessment revealed almost total loss of active glenohumeral abduction in the pseudoparalytic group. Conclusion Despite global tear extension, the single most important predictor for preserved shoulder function is the integrity of the inferior subscapularis insertion. Furthermore, electromyographic evaluation identifies a well-differentiated deltoid innervation as beneficial for a well-preserved shoulder function, but it does not protect from pseudoparalysis.

Knee Surgery, Sports Traumatology, Arthroscopy, 21 (3), ISSN:0942-2056, ISSN:1433-7347

Archives of Orthopaedic and Trauma Surgery, 132 (9), ISSN:0936-8051, ISSN:0344-8444, ISSN:1434-3916

Purpose: Anteroposterior knee stability is a relevant factor for the decision-making process of various surgical procedures. In degenerative joints when the implantation of unicompartimental prostheses or corrective osteotomies of the limb are planned, the integrity of the anteroposterior stability with an intact ACL has been regarded as a necessary prerequisite. We hypothesise that joint degeneration, however, may influence the anteroposterior knee laxity. Therefore, we set out to test this hypothesis simulating a progressively ‘degenerated' joint in an experimental cadaveric setting. Methods: Twelve intact transfemorally resected Thiel-fixated cadaver knee joints were divided into 2 groups for manipulation in the medial or lateral compartment. In each knee, we performed (1) unilateral total meniscectomy; (2) simulation of advanced osteoarthritis, by unilateral total cartilage debridement; (3) simulation of a unilateral tibial impression fracture, by resection of 5mm of the tibial plateau; (4) transection of the ACL. The KT-1000 arthrometer was used to measure the extent of anteroposterior translation at 30° of knee flexion. Results: The mean value for tibial anteroposterior translation before intervention was 3.2mm (SD: ±0.8). The mean translation after each intervention was 4.6mm (SD: ±0.9; +44%; n.s.) after meniscectomy, 5.9mm (SD: ±1.5; +84%; P

Introduction Interference screws used in fixation of anterior cruciate ligament (ACL) hamstring grafts create mechanical hold by forcing the graft into frictional contact with the bone tunnel. We analyzed the resultant graft–tunnel contact pressure using an in vitro model of human cadaver 8 mm hamstring grafts. Methods Contact characteristics were assessed using both pressure sensitive films and a force sensor. Two screw sizes were investigated (8 and 9 mm in an 8 mm Sawbone tunnel), both with and without a bone wedge between graft and screw. Separately, time dependent relaxation of contact force was recorded over a one hour epoch and associated tendon water loss was measured. Pullout testing of 8 mm tendon grafts from 8 mm holes in Sawbone and porcine femora were performed after 1 min and 1 h. Results During screw insertion, measured peak pressures (> 40 MPa) exceeded the compressive failure stress of metaphyseal bone by more than an order of magnitude. Using a bone wedge between tendon and screw reduced local peak pressure by 85% but produced also inferior average contact pressure. In all approaches, initially achieved graft contact pressure rapidly decreased to approximately 25% within 30 min. Pullout strength was significantly reduced after 1 h in comparison to 1 min in porcine bone as well as Sawbone. Conclusion Viscoelastic adaptation of the tendon is severe and critically reduces effective graft–bone contact pressure. Consideration of this newly recognized effect may open new and improved approaches for tendon graft fixation.

BackgroundRetraction, atrophy and fatty infiltration are signs subsequent to chronic rotator cuff tendon tears. They are associated with an increased pennation angle and a shortening of the muscle fibers in series. These deleterious changes of the muscular architecture are not reversible with current repair techniques and are the main factors for failed rotator cuff tendon repair. Whereas fast stretching of the retracted musculotendinous unit results in proliferation of non-contractile fibrous tissue, slow stretching may lead to muscle regeneration in terms of sarcomerogenesis. To slowly stretch the retracted musculotendinous unit in a sheep model, two here described tensioning devices have been developed and mounted on the scapular spine of the sheep using an expandable threaded rod, which has been interposed between the retracted tendon end and the original insertion site at the humeral head. Traction is transmitted in line with the musculotendinous unit by sutures knotted on the expandable threaded rod. The threaded rod of the tensioner is driven within the body through a rotating axis, which enters the body on the opposite side. The tendon end, which was previously released (16 weeks prior) from its insertion site with a bone chip, was elongated with a velocity of 1 mm/day.ResultsAfter several steps of technical improvements, the tensioner proved to be capable of actively stretching the retracted and degenerated muscle back to the original length and to withstand the external forces acting on it.ConclusionThis technical report describes the experimental technique for continuous elongation of the musculotendinous unit and reversion of the length of chronically shortened muscle.

Efficient and successful arthroscopic surgery relies on methodical and well-organized suture management. However, it is relatively common, especially in complex arthroscopic procedures, that sutures invariability become entangled or twisted as a result of repeated suture shuttling from portal to portal and between individual suture limbs. When this occurs, this can make antegrade suture passage or arthroscopic knot tying challenging. We describe a simple and efficient technique that allows simultaneous retrieval of 2 suture limbs while ensuring that the sutures are disentangled.

Knee Surgery, Sports Traumatology, Arthroscopy, 19 (12), ISSN:0942-2056, ISSN:1433-7347

Case report In the presented case, an isolated vastus lateralis tendon tear resulted in a negative pennation angle of the distal muscle fibers acting paradoxical to the physiological direction of the proximal muscle fibers. This observation makes the value of an in situ repair of a far retracted tendon tear with interposition of a graft questionable and emphasizes early over late anatomic surgical restoration of the muscle architecture after tendon tears.

The acromiohumeral distance (AHD) measured on conventional, true anteroposterior radiographs taken with the patient standing and the arm held in neutral rotation can predict the presence or absence of a large, chronic rotator cuff tears, and narrowing of the acromiohumeral distance can predict irreparability of rotator cuff tears. The relation between AHD measured on conventional radiographs and the integrity of the rotator cuff tendons is well known. Conversely, the correlation between the AHD on conventional radiographs and that measured on magnetic resonance imaging (MRI) or computed tomography (CT) scans is unknown. It has also not been determined which method correlates better with fatty infiltration of the rotator cuff muscles and might thereby be a better prognostic value for the outcome of rotator cuff repair. Conventional radiographs, plus MRI and or CT studies taken at the same time of patients with rotator cuff tears, shoulder instability, primary glenohumeral osteoarthritis, or idiopathic frozen shoulder, were randomly selected, and the AHD was measured both on conventional radiographs and on MRI or CT. The values were correlated with the stage of fatty degeneration of the rotator cuff muscles in the cases of rotator cuff tears. The AHD on conventional radiographs was larger than on MRI and CT, and correlation of the values measured (conventional radiography vs MRI and CT) could be demonstrated. For rotator cuff diseases, a significant but moderate correlation (r = 0.6; P < .05) between conventional and MRI was identified, and the conventional values were approximately 0.6 mm greater than the corresponding MRI values. It is, therefore, possible to use the AHD read on MRI or CT studies for prognostic reasons, provided the values obtained are converted accordingly and remembering that the correlation of the values is only moderate.

Background The decision whether to treat conservatively or reconstruct surgically a torn anterior cruciate ligament (ACL) is an ongoing subject of debate. The high prevalence and associated public health burden of torn ACL has led to continuous efforts to determine the best therapeutic approach. A critical evaluation of benefits and expenditures of both treatment options as in a cost effectiveness analysis seems well-suited to provide valuable information for treating physicians and healthcare policymakers. Methods A literature review identified four of 7410 searched articles providing sufficient outcome probabilities for the two treatment options for modeling. A transformation key based on the expert opinions of 25 orthopedic surgeons was used to derive utilities from available evidence. The cost data for both treatment strategies were based on average figures compiled by Orthopaedic University Hospital Balgrist and reinforced by Swiss national statistics. A decision tree was constructed to derive the cost-effectiveness of each strategy, which was then tested for robustness using Monte Carlo simulation. Results Decision tree analysis revealed a cost effectiveness of 16,038 USD/0.78 QALY for ACL reconstruction and 15,466 USD/0.66 QALY for conservative treatment, implying an incremental cost effectiveness of 4,890 USD/QALY for ACL reconstruction. Sensitivity analysis of utilities did not change the trend. Conclusion ACL reconstruction for reestablishment of knee stability seems cost effective in the Swiss setting based on currently available evidence. This, however, should be reinforced with randomized controlled trials comparing the two treatment strategies.

BackgroundIt seems appropriate to assume, that for a full and strong global shoulder function a normally innervated and active deltoid muscle is indispensable. We set out to analyse the size and shape of the deltoid muscle on MR-arthrographies, and analyse its influence on shoulder function and its adaption (i.e. atrophy) for reduced shoulder function.MethodsThe fatty infiltration (Goutallier stages), atrophy (tangent sign) and selective myotendinous retraction of the rotator cuff, as well as the thickness and the area of seven anatomically defined segments of the deltoid muscle were measured on MR-arthrographies and correlated with shoulder function (i.e. active abduction). Included were 116 patients, suffering of a rotator cuff tear with shoulder mobility ranging from pseudoparalysis to free mobility. Kolmogorov-Smirnov test was used to determine the distribution of the data before either Spearman or Pearson correlation and a multiple regression was applied to reveal the correlations.ResultsOur developed method for measuring deltoid area and thickness showed to be reproducible with excellent interobserver correlations (r = 0.814–0.982).The analysis of influencing factors on active abduction revealed a weak influence of the amount of SSP tendon (r = −0.25; p ConclusionsOur data support that in chronic rotator cuff tears, there seems to be no disadvantage to exhausting conservative treatment and to delay implantation of reverse total shoulder arthroplasty, as the shape of deltoid muscle seems only to be influenced by natural aging, but to be independent of reduced shoulder motion.

Background: This is the first study assessing the properties of large-diameter degradable sutures relevant for orthopedic applications over the course of in vitro incubation for 2 months. The data we present here provide guidance to the orthopedic surgeon in predicting the long-term performance of suture materials used everyday in surgical practice. Methods: Five different absorbable (Vicryl, Maxon, Monocryl, PDS II, Vicryl rapide) and one non-absorbable (Ethibond) suture materials were tested. Measurements were made at five time points during the 56 days of incubation under physiological conditions (37.0 ± 0.02 °C; pH 7.4 ± 0.2). The following variables were recorded: load to failure, strain at maximal load as elongation normalized to original length, stiffness as the ratio of load to displacement on the linear proportion of the stress strain curve, and hysteresis as area under the curve of the stress strain curve. Results: Vicryl was the strongest fiber on day 0 (195 N); however, by day 42, the tensile strength of the suture reduced to 14 N. Between days 14 and 28, PDS II (171 N) and Maxon (182 N) sustained the highest loads. Monocryl ( p = 0.003) and Maxon ( p < 0.001) showed an increasing strain with time, whereas Vicryl ( p = 0.002) and Vicryl rapide ( p = 0.007) revealed an increasing material stiffness. Furthermore, both Vicryl ( p = 0.053) and Monocryl ( p < 0.001) had an increasing hysteresis with ongoing degradation. Maxon, PDS II, and Ethibond showed stable material properties during the 2 months. Conclusions: The three absorbable sutures Vicryl, PDS II, and Maxon could sustain higher loads during the first 2 weeks than the non-absorbable Ethibond. Unexpectedly, Maxon and PDS II maintained their elastic properties in spite of their proceeding degradation and loss of tensile strength., Journal of Orthopaedic Surgery and Research, 11, ISSN:1749-799X