Search

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.

Purpose: The aim of this work is to determine face validity and construct validity of a new virtual-reality-based simulator for diagnostic and therapeutic knee arthroscopy. Methods: The study tests a novel arthroscopic simulator based on passive haptics. Sixty-eight participants were grouped into novices, intermediates, and experts. All participants completed two exercises. In order to establish face validity, all participants filled out a questionnaire concerning different aspects of simulator realism, training capacity, and different statements using a seven-point Likert scale (range 1-7). Construct validity was tested by comparing various simulator metric values between novices and experts. Results: Face validity could be established: overall realism was rated with a mean value of 5.5 points. Global training capacity scored a mean value of 5.9. Participants considered the simulator as useful for procedural training of diagnostic and therapeutic arthroscopy. In the foreign body removal exercise, experts were overall significantly faster in the whole procedure (6min 24s vs. 8min 24s, p<0.001), took less time to complete the diagnostic tour (2min 49s vs. 3min 32s, p=0.027), and had a shorter camera path length (186 vs. 246cm, p=0.006). Conclusion: The simulator achieved high scores in terms of realism. It was regarded as a useful training tool, which is also capable of differentiating between varying levels of arthroscopic experience. Nevertheless, further improvements of the simulator especially in the field of therapeutic arthroscopy are desirable. In general, the findings support that virtual-reality-based simulation using passive haptics has the potential to complement conventional training of knee arthroscopy skills. Level of evidence: II.

BACKGROUND Accurate glenoid positioning in reverse total shoulder arthroplasty (RSA) is important to achieve satisfying functional outcome and prosthesis longevity. Optimal component placement can be challenging, especially in severe glenoid deformities. The use of patient-specific instruments (PSI) and 3D computer-assisted optical tracking navigation (NAV) are already established methods to improve surgical precision. Augmented reality technology (AR) promises similar results at low cost and ease of use. With AR, the planned component placement can be superimposed to the surgical situs and shown directly in the operating field using a head mounted display. We introduce a new navigation technique using AR via head mounted display for surgical navigation in this feasibility study, aiming to improve and enhance the surgical planning. METHODS 3D surface models of ten human scapulae were printed from computed tomography (CT) data of cadaver scapulae. Guidewire positioning of the central back of the glenoid baseplate was planned with a dedicated computer software. A hologram of the planned guidewire with dynamic navigation was then projected onto the 3D-created models of the cadaver shoulders. The registration of the plan to the anatomy was realized by digitizing the glenoid surface and the base of the coracoid with optical tracking using a fiducial marker. After navigated placement of the central guidewires, another CT imaging was recorded, and the 3D model was superimposed with the preoperative planning to analyze the deviation from the planned and executed central guides trajectory and entry point. RESULTS The mean deviation of the ten placed guidewires from the planned trajectory was 2.7° ± 1.3° (95% CI 1.9°; 3.6°). The mean deviation to the planned entry point of the ten placed guidewires measured 2.3 mm ± 1.1 mm (95% CI 1.5 mm; 3.1 mm). CONCLUSION AR may be a promising new technology for highly precise surgical execution of 3D preoperative planning in RSA.

PURPOSE: To report and analyse factors affecting the outcome of streptococcal periprosthetic joint infections (PJIs). METHODS: A retrospective analysis of consecutive streptococcal PJIs was performed. Musculoskeletal Infection Society 2013 criteria were used. Outcome was compared with a prospective PJI cohort from the same institution. RESULTS: The most common isolated streptococcal species was Streptococcus dysgalactiae (9/22, 41%) among 22 patients included. Surgical treatment consisted of DAIR (debridement, antibiotics, irrigation and retention) in 12 (55%), one-stage revision arthroplasty in one (4%), two-stage revision arthroplasty in eight (37%) and implant removal in one (4%) patient. An infection free-outcome was achieved in 15 cases (68%), whilst seven (32%) patients failed initial revision and relapsed with the same pathogen, from which six were treated with DAIR and one with one-stage revision arthroplasty. No failures were observed in patients who received a two-stage revision. Failure rates did not differ in the cases treated with rifampin (1/5) from those without 6/17 (p = 0.55). There was no correlation between the length of antibiotic treatment and relapse (p = 0.723). In all failures, a persistent distant infection focus was identified at the time of relapse. Compared with our prospective PJI cohort, relapse rates were significantly higher 32% vs 12% (p < 0.05). CONCLUSION: No correlation with the use of rifampin or length of antibiotic treatment was found. No failures were observed in patients who received a two-stage revision, which may be the surgical treatment of choice. A distant persisting infection focus could be the reason for PJI relapse with recurrent hematogenous seeding in the joint.

Background The number of implanted reverse total shoulder arthroplasties (RTSA) is increasing worldwide. To improve patient care, institutional and national arthroplasty registries are being established worldwide to record outcome data. This article aims to describe the setup of an RTSA database in a high-volume university orthopedic hospital. Methods All patients who received an RTSA at the authors’ tertiary referral hospital have been followed and individual datasets have been systematically recorded in a REDCap database since 2005. The data are captured longitudinally as a primary preoperative survey and as a regular or irregular postoperative follow-up. All baseline demographic data, patient history, surgical details, arthroplasty details, adverse events, and radiographic and clinical outcome scores (Constant–Murley score, Subjective Shoulder Value, range of motion) are recorded. Results A total of 1433 RTSA were implanted between January 2005 and December 2020. Of these, 1184 (83%) were primary implantations and 249 (17%) were secondary cases. The cohort had a mean age of 70 ± 10 years, was 39% male, and was classified ASA II in 59%. The lost to follow-up rate was 18% after 2 years, 22% after 5 years, and 53% after 10 years. The overall complication rate with 2 years minimum follow-up was 18% (156/854 shoulders) with reintervention in 10% (82/854 shoulders). Conclusion A well-managed institutional arthroplasty registry, including structured clinical and radiological follow-up assessments, offers the opportunity for high-quality long-term patient and arthroplasty outcome analysis. Such data are not only helpful for analyzing patient outcome and implant survival, but will be increasingly important to justify our daily clinical practice against different stakeholders in the various health care systems. = Hintergrund Die Zahl implantierter inverser Schultertotalprothesen (RTSA) ist international steigend. Um die Patientenversorgung zu verbessern, werden weltweit in

INTRODUCTION Little information is available on the clinical and radiographic outcome of intraoperative, non- to minimally displaced humeral fractures that occur during implantation of a stemmed, reverse shoulder prosthesis but are only recognized on routine postoperative radiographs. The goal of this study is to report the clinical and radiographic outcome for this rarely reported fracture type. MATERIALS AND METHODS 39 conservatively treated non- to minimally displaced intraoperative periprosthetic humeral fractures after stemmed RTSA were detected from our radiographic database between 1.1.2006 and 31.1.2018. Exclusion criteria were lack of patient consent, preoperative humeral fracture, and revision arthroplasties. Clinical (absolute and relative Constant score, the Subjective Shoulder Value) and radiographic (conventional radiographs) assessment was performed preoperatively, at 6 weeks (only radiographically) and at latest follow-up with a minimum follow-up of 2 years. RESULTS 35 patient's with a mean age of 72 years (range 32-88, SD ± 11 years) and a mean follow-up of 53 months (range 24-124, SD ± 31) were included in the study. At latest follow-up, all clinical outcome parameters except external rotation improved significantly. A complication rate of 17% (n:6) was recorded. At 6 weeks after the index surgery, none of the radiographs showed a fracture displacement or a sintering of the stem. At latest follow-up, all fractures were healed and no stem loosening was observed in any of the shoulders. CONCLUSIONS Non- to minimally displaced intraoperative periprosthetic humeral fractures in RTSA have an incidence of about 5% in this series of mainly uncemented press-fit stems. They generally heal without any further treatment and are not associated with stem loosening or compromise the clinical outcome after primary RTSA. Except slight restriction in the postoperative rehabilitation protocol, no further attention or action is needed.

BACKGROUND The injection of mesenchymal stem cells (MSCs) mitigates fat accumulation in released rotator cuff muscle after tendon repair in rodents. PURPOSE To investigate whether the injection of autologous MSCs halts muscle-to-fat conversion after tendon repair in a large animal model for rotator cuff tendon release via regional effects on extracellular fat tissue and muscle fiber regeneration. STUDY DESIGN Controlled laboratory study. METHODS Infraspinatus (ISP) muscles of the right shoulder of Swiss Alpine sheep (n = 14) were released by osteotomy and reattached 16 weeks later without (group T; n = 6) or with (group T-MSC; n = 8) electropulse-assisted injection of 0.9 Mio fluorescently labeled MSCs as microtissues with media in demarcated regions; animals were allowed 6 weeks of recovery. ISP volume and composition were documented with computed tomography and magnetic resonance imaging. Area percentages of muscle fiber types, fat, extracellular ground substance, and fluorescence-positive tissue; mean cross-sectional area (MCSA) of muscle fibers; and expression of myogenic (myogenin), regeneration (tenascin-C), and adipogenic markers (peroxisome proliferator-activated receptor gamma [PPARG2]) were quantified in injected and noninjected regions after recovery. RESULTS At 16 weeks after tendon release, the ISP volume was reduced and the fat fraction of ISP muscle was increased in group T (137 vs 185 mL; 49% vs 7%) and group T-MSC (130 vs 166 mL; 53% vs 10%). In group T-MSC versus group T, changes during recovery after tendon reattachment were abrogated for fat-free mass (-5% vs -29%, respectively; P = .018) and fat fraction (+1% vs +24%, respectively; P = .009%). The area percentage of fat was lower (9% vs 20%; P = .018) and the percentage of the extracellular ground substance was higher (26% vs 20%; P = .007) in the noninjected ISP region for group T-MSC versus group T, respectively. Regionally, MCS injection increased tenascin-C levels (+59%) and the water fracti

BACKGROUND To achieve an optimal clinical outcome in reverse total shoulder arthroplasty (RSA), accurate placement of the components is essential. The recently introduced navigation technology of augmented reality (AR) through head-mounted displays (HMD) offers a promising new approach to visualize the anatomy and navigate component positioning in various orthopedic surgeries. We hypothesized that AR through HMD is feasible, reliable, and accurate for guidewire placement in RSA baseplate positioning. METHODS Twelve human cadaver shoulders were scanned with computed tomography (CT) and RSA baseplate positioning was 3-D planned using dedicated software. The shoulders were prepared through a deltopectoral approach and an augmented reality hologram was superimposed using the HMD Microsoft HoloLense. The central guidewire was then navigated through the HMD to achieve the planned entry point and trajectory. Postoperatively, the shoulders were CT-scanned a second time and the deviation from the planning was calculated. RESULTS The mean deviation of the entry point was 3.5 mm ± 1.7 mm (95% CI 2.4 mm; 4.6 mm). The mean deviation of the planned trajectory was 3.8° ± 1.7° (95% CI 2.6°; 4.9°). CONCLUSION Augmented reality seems feasible and reliable for baseplate guidewire positioning in reverse total shoulder arthroplasty. The achieved values were accurate.

INTRODUCTION In the field of arthroscopic rotator cuff repair (ARCR), reporting standards of published studies differ dramatically, notably concerning adverse events (AEs). In addition, prognostic studies are overall methodologically poor, based on small data sets and explore only limited numbers of influencing factors. We aim to develop prognostic models for individual ARCR patients, primarily for the patient-reported assessment of shoulder function (Oxford Shoulder Score (OSS)) and the occurrence of shoulder stiffness 6 months after surgery. We also aim to evaluate the use of a consensus core event set (CES) for AEs and validate a severity classification for these events, considering the patient's perspective. METHODS AND ANALYSIS A cohort of 970 primary ARCR patients will be prospectively documented from several Swiss and German orthopaedic clinics up to 24 months postoperatively. Patient clinical examinations at 6 and 12 months will include shoulder range of motion and strength (Constant Score). Tendon repair integrity status will be assessed by ultrasound at 12 months. Patient-reported questionnaires at 6, 12 and 24 months will determine functional scores (subjective shoulder value, OSS), anxiety and depression scores, working status, sports activities, and quality of life (European Quality of Life 5 Dimensions 5 Level questionnaire). AEs will be documented according to a CES. Prognostic models will be developed using an internationally supported regression methodology. Multiple prognostic factors, including patient baseline demographics, psychological, socioeconomic and clinical factors, rotator cuff integrity, concomitant local findings, and (post)operative management factors, will be investigated. ETHICS AND DISSEMINATION This project contributes to the development of personalised risk predictions for supporting the surgical decision process in ARCR. The consensus CES may become an international reference for the reporting of complications in clinical studie

Background The implantation rates of reverse total shoulder arthroplasties (RTSAs) are increasing worldwide, resulting in higher absolute numbers of the associated complications and revision surgeries. This requires the discussion of salvage therapies for failed RTSAs without revision to a new RTSA. Revision to hemiarthroplasty may offer a valid fallback option in certain cases. This study aimed to analyze the incidence, indications, and clinical outcomes, especially the reduction in pain levels compared to a matched control group. Methods Our prospectively enrolled patient cohort of RTSA implantations at a tertiary referral center between January 2005 and December 2018 was retrospectively queried for revision to a hemiarthroplasty. For clinical outcome evaluation, a minimum follow-up duration of 2 years after revision to hemiarthroplasty was required. Clinical outcome measures were compared to two matching groups, one with RTSA preserving revision and one without any reintervention. The outcome measures were the absolute and relative Constant-Murley score (aCS and rCS), Subjective Shoulder Value (SSV), range of motion, and pain. Results A total of 21 out of 1237 RTSAs (1.7%) underwent salvage revision to hemiarthroplasty at a mean time of 20 ± 21 months (range, 1-75 months). Of those, 12 were available for a minimum follow-up of 2 years after revision to a hemiarthroplasty. The main indications were glenoid loosening (8/12), scapular spine fracture (2/12), and instability (2/21). Clinical outcome was analyzed at a mean follow-up period of 46 ± 26 months (24 months to 123 months) after revision to a hemiarthroplasty. The revision significantly reduced CS pain from 6 ± 4 points to 12 ± 3 points (scale 0 to 15 with 15 as optimum, P < .01). The aCS, rCS, SSV, and range of motion did not improve. Comparison with the RTSA preserving revision group and the RTSA group without reintervention showed significantly worse outcome scores for aCS (33 ± 10 vs. 55 ± 19 vs. 69 ± 12

Background The treatment of complex proximal humerus fractures with hemiarthroplasty is associated with a high failure rate due to secondary displacement of the tuberosities. It was the aim of this in-vitro study to compare the mechanical stability of tuberosity reattachment obtained with the so-called "Cow-Hitch" (CH) cerclage compared with conventional tuberosity reattachment. Methods A 4-part proximal humerus fracture was created in 10 fresh-frozen, human cadaveric shoulders. The greater and lesser tuberosity were reattached to the hemiarthroplasty stem with in total 4 CH Cerclages in the Cow-Hitch group. The conventional technique-recommended for the tested implant-was used in the control group using 6 sutures. A total of 5000 loading cycles with forces of 350N were applied, while motion (in mm) of the tuberosities was recorded in 3 directions (anteroposterior = AP, mediolateral = ML, inferosuperior = IS) with a telecentric camera. Results After 5000 loading cycles, the CH group showed less fragment displacement (AP: 2.3 ± 2.3 mm, ML: 1.8 ± 0.9 mm, IS: 1.3 ± 0.5 mm) than the conventional group (AP: 9.8 ± 12.3 mm, ML: 5.5 ± 5.6 mm, IS: 4.5 ± 4.7 mm). The differences were not statistically significant (AP: P = .241; ML: P = .159; IS: P = .216). The lesser tuberosity fragment displacement in the CH group after 5000 cycles was less in the AP (2.3 ± 3.3 vs. 4.0 ± 2.8, P = .359) and IS (1.9 ± 1.2 vs. 3.1 ± 1.8; P = .189) directions but higher in the ML direction (7.2 ± 5.7 vs 6.3 ± 3.6, P = .963). Conclusions In-vitro, "Cow-Hitch" cerclage results in mean greater tuberosity displacements of 2 mm and reliably prevents displacements greater than 5 mm. In contrast, the conventional fixation technique yields unreliable, variable stability with low to complete displacement upon cyclical loading.

BACKGROUND Primarily posterior bone deficient (dysplastic) (Walch type C) or secondarily eroded (Walch type B2 or B3) glenoids represent a surgical challenge for shoulder arthroplasty. Due to the posteriorly static decentered head, reverse total shoulder arthroplasty (RTSA) is often considered as the treatment of choice. The purpose of this study is to report the clinical and radiographic outcomes, complications and reoperations of RTSA for posteriorly deficient glenoids. MATERIALS AND METHODS All patients who underwent RTSA for osteoarthritis secondary to underlying glenoid deficiency (Walch type B2, B3 and C) between 2005 and 2018 (study group), were identified from our institutional shoulder arthroplasty database and gender- and age-matched to a cohort of patients with normal glenoid bone stock (control group). Longitudinal pre- and postoperative clinical [Constant-Murley (CS) score, Subjective Shoulder Value (SSV)] and radiographic outcomes were assessed. RESULTS We included 188 patients (94 in each group). The median follow-up was 43 ± 26 (24-144) months in the study group and 59 ± 32 (24-124) months in the control group. The glenoid deficiency was addressed by using glenoid bone reconstruction. The surgical site complication and revision rate of RTSA in patients with bony deficient glenoids were 17% and 7%. Although glenoid loosening was slightly higher in the study group (5 vs. 2), overall no significant differences were found between the study and control groups in satisfaction scores, preoperative and postoperative absolute and relative Constant scores, complication and revision rates, respectively. CONCLUSION Reverse total shoulder arthroplasty (RTSA) seems to be a valuable treatment option for patients with primary (dysplasia) or secondary (wear) posterior glenoid deficiency. Although severe glenoid bone loss seems to be a risk factor for glenoid component failure, the overall complication and revision rates as well as clinical and radiographic outcome ar

INTRODUCTION Coronal plane fractures of the distal humerus are relatively rare and can be challenging to treat due to their complexity and intra-articular nature. There is no gold standard for surgical management of these complex fractures. The purpose of this study was to compare the biomechanical stability and strength of two different internal fixation techniques for complex coronal plane fractures of the capitellum with posterior comminution. MATERIALS AND METHODS Fourteen fresh frozen, age- and gender-matched cadaveric elbows were 3D-navigated osteotomized simulating a Dubberley type IIB fracture. Specimens were randomized into one of two treatment groups and stabilized with an anterior antiglide plate with additional anteroposterior cannulated headless compression screws (group antiGP + HCS) or a posterolateral distal humerus locking plate with lateral extension (group PLP). Cyclic testing was performed with 75 N over 2000 cycles and ultimately until construct failure. Data were analyzed for displacement, construct stiffness, and ultimate load to failure. RESULTS There was no significant difference in displacement during 2000 cycles (p = 0.291), stiffness (310 vs. 347 N/mm; p = 0.612) or ultimate load to failure (649 ± 351 vs. 887 ± 187 N; p = 0.140) between the two groups. CONCLUSIONS Posterolateral distal humerus locking plate achieves equal biomechanical fixation strength as an anterior antiglide plate with additional anteroposterior cannulated headless compression screws for fracture fixation of complex coronal plane fractures of the capitellum. These results support the use of a posterolateral distal humerus locking plate considering the clinical advantages of less invasive surgery and extraarticular metalware. LEVEL OF EVIDENCE Biomechanical study.

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 increas

Chronic musculotendinous retraction, shortening and fibrosis after distal biceps tendon tears makes a primary reconstruction often difficult or even impossible. Interposition reconstruction with allograft provides a solution, however there is no consensus about appropriate intraoperative graft length adjustment. Therefore, the purpose of this study was to find a practical reference value for distal biceps tendon length adjustment. Three-dimensional surface models of healthy distal biceps tendons were created based on 85 MRI scans. The tendon length was measured from the myotendinous junction to the insertion on the bicipital tuberosity. Inter-epicondylar distance (IED) and radial head diameter (RHD) were measured on antero-posterior radiographs as a surrogate for patient size. Correlations between the tendon length and IED, RHD and patient's height (PH) were calculated. Mean length of the external part of the distal biceps tendon was 69mm (female 64mm, male 71mm). The tendon length in mm was on average 1.1 times of the IED (mm), 3 times of the RHD (mm) and 0.4 times of PH (cm). Herewith, the tendon length could be predicted within a narrow range of +/-1cm in 84% by using IED, 82% by using RHD and 80% by using PH. Intra- and inter-reader reliabililty of IED and RHD was excellent (R2 = 0.938-0.981). The distal biceps tendon length can be best predicted within 1cm with an accuracy of 82-84% using the IED and RHD with an excellent intra- and inter-reader reliability.

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 Reverse shoulder arthroplasty (RSA) is a valuable solution for patients with shoulder pain or injury primarily due to a rotator cuff tear or secondary to traumatic events. Nevertheless, several complications are known to appear, with the most frequent being scapular notching (SN) on the inferior and posterior scapular neck. Controversial data exist about the clinical relevance of SN. Since further consequences are still not clearly understood, we aimed to provide more clarity on which factors, especially external rotation (ER), contribute to the appearance and progress of notching. Methods Constant Score (CS), Subjective Shoulder Value (SSV), flexion, abduction, and ER were evaluated retrospectively in 153 shoulders of 147 patients (mean age 79±7.7 years; 62% women) who underwent RSA between 2005 and 2010. Anteroposterior radiographs were evaluated before and 1, 2, 3, and 5 years after RSA for SN according to the Sirveaux classification. The evaluation was performed by two independent surgeons. Spearman’s coefficient and t-test were used. Results CS, SSV, flexion, and abduction increased significantly 1 year after RSA compared to before (all p < 0.0001). No improvement was shown for ER between the same timepoints. Between 2 and 5 years of follow-up, only flexion decreased by 5°(p = 0.02) while CS, SSV, abduction, and ER remained constant. After RSA, notching increases over time. There was no association between SN and CS, SSV, flexion, abduction or ER at any of the measured timepoints. Higher flexion correlated with higher abduction after RSA at every follow-up (1 year r = 0.88, 2 years r = 0.89, 3 years r = 0.86, 5 years r = 0.86). The interrater correlation test showed a strong correlation (r = 0.7). Conclusion We verified the functional benefits of RSA for patients. Additionally, our findings show that despite radiographic progression of notching and unchanged limited ER, the postoperative improvements in CS, SSV, flexion, and abduction are preserved o

BACKGROUND Understanding muscle and tendon anatomy is of tremendous importance to achieve optimal surgical execution and results in tendon transfers around the shoulder. The aim of this study was to introduce and describe an additional distal muscle slip of the teres major (TM). METHODS Sixteen fresh-frozen cadaver shoulders were dissected with the deltopectoral approach. The ventral latissimus dorsi (LD) tendon was harvested, and the shoulders were analyzed for the presence/absence of a distal teres major slip (dTMs) and its dimensions and relationship with the TM and LD tendons. RESULTS The dTMs was identified in 12 shoulders (75%). It was always distal to the TM tendon and visible during the deltopectoral approach. There was a clear separation between the TM proximally and dTMs tendon distally. At the humeral insertion, both tendons had a common epimyseal sheet around the teres major and inserted continuously at the humerus. The mean width of the dTMs tendon at the insertion was 13 ± 4 mm (range, 7-22 mm). The total lengths of the dTMs tendon and LD tendon were 40 ± 7 mm (range, 25-57 mm) and 69 ± 7 mm (range, 57-79 mm), respectively (p < 0.001). The dTMs muscle showed direct adhesions in ten shoulders (83%) with the LD muscle. CONCLUSIONS This is the first macroscopic description of an additional distal slip of the teres major muscle. The dTMs has a separate (distal) but continuous (mediolateral) insertion at the humerus within a common epimyseal sheet around the TM. The dTMs tendon is visible during the deltopectoral approach and can therefore provide a lead structure, particularly in ventral LD transfers with the deltopectoral approach.