Rotator Cuff Tears are Significantly More Frequent in Recurrent Shoulder Instability Patients With Initial Dislocation at Age 40 or Older.

PURPOSE: To investigate and compare the pathologies and clinical outcomes of patients with traumatic anterior shoulder instability who underwent arthroscopic stabilization at 40 years or older between shoulders with initial dislocation before age 40 years and at 40 years or after. METHODS: Shoulders that underwent arthroscopic stabilization for recurrent traumatic anterior shoulder instability at 40 years or older with a minimum of 2-year follow-up were included. The subjects were divided into 2 groups according to age at initial dislocation after propensity score matching to reduce potential bias: younger than 40 years (group 1) and 40 years or older (group 2). Radiographic findings, pathologies, clinical outcomes, and complications were compared between the groups. RESULTS: Group 1 included 56 shoulders in 56 patients (26 men and 30 women) with a mean age of 51 years (range, 40-77 years). Group 2 included 28 shoulders in 28 patients (13 men and 15 women) with a mean age of 51 years (range, 40-77 years). Glenoid bone loss was greater in group 1 than in group 2 (P = .004). Rotator cuff tears were more frequently observed in group 2 than in group 1 (P < .001). Both groups showed significant improvement in the West Ontario Shoulder Instability Index score (P < .001 for each) and flexion (P < .001 for each). The recurrence rate was 4% in group 1 and 7% in group 2. CONCLUSIONS: Rotator cuff tears are significantly more frequent in recurrent shoulder instability patients with initial dislocation at age 40 or older. Arthroscopic stabilization yielded a low recurrence rate and favorable outcomes with a good return-to-sport rate in patients 40 years or older. LEVEL OF EVIDENCE: Level III, retrospective comparative prognostic trial.

Management of ulnar collateral ligament injury in baseball athletes: An online survey in Japanese surgeons.

BACKGROUND: The management of ulnar collateral ligament (UCL) injuries widely varies among surgeons. Although various treatment options have been proposed including surgical and conservative treatments, no golden standard treatment strategy has been established of yet. The American survey reported an overall experienced and well-trained cohort of surgeons often reached consensus opinions on how to approach UCL injury. However, the consensus among Japanese surgeons on the treatment of UCL injuries remains unclear. The purpose of this study was to survey current trends among Japanese orthopaedic surgeons in the treatment of UCL injuries in baseball players. METHODS: An online survey was distributed to the active members of the Japanese doctor's network for baseball injury prevention, which was formed by partial members of the medical committee in the Japan Baseball Council. The survey was composed of three sections: demographics of the surveyees, preferred operative and nonoperative management of UCL injuries, and five fictional clinical case scenarios of baseball players with a UCL injury. RESULTS: The 131 e-mailed invitations to society members yielded 78 completed online surveys with a participation rate of 60%. Sixty-four respondents (82%) reported >15 years of clinical experience. Sixty-five respondents (83%) performed ≤5 UCL reconstructions per year. As nonsurgical management of UCL injuries, seventy-four surgeons (95%) preferred physiotherapy followed by intraarticular injection (46%). For surgical management, seventy-three surgeons (93%) preferred UCL reconstruction. Of the five case scenarios, a consensus was reached in three cases: to perform surgery on the patient with full-thickness UCL tear. When operative management was the preferred option, a consensus was reached to perform UCL reconstruction. CONCLUSION: Japanese doctors involved in the treatment of baseball injuries reached a consensus to indicate high-level athletes with a full-thickness UCL tear for surgery. When operative management was the preferred option, a consensus was reached to perform UCL reconstruction. These results may contribute to the decision-making for managing UCL injuries.

Arthroscopic Iliac Bone Grafting for Traumatic Anterior Shoulder Instability With Significant Glenoid Bone Loss Yields Low Recurrence and Good Outcome at a Minimum of Five-Year Follow-Up.

PURPOSE: The purpose of this study was to investigate the clinical and radiographic outcomes of arthroscopic iliac bone grafting with capsulolabral reconstruction for severe glenoid bone loss with a minimum of 5 years' follow-up. METHODS: The inclusion criterion was shoulders that underwent arthroscopic iliac bone grafting for >20%-25% glenoid defect between January 2007 and April 2014, and the exclusion criterion was <5 years' follow-up. Iliac crest bone grafts of approximately 2.0 cm length and 0.8 cm height were arthroscopically fixed to the anterior glenoid using 2 cannulated screws followed by capsulolabral repair. Rowe score, Western Ontario Shoulder Instability Index (WOSI), and passive range of motion were evaluated. Radiographic findings including the Kellgren and Lawrence osteoarthritis grade and graft integration on 3-dimensional computed tomography at the final follow-up were also evaluated. RESULTS: Forty-eight shoulders met the inclusion criteria, and 24 shoulders with ≥5 years' follow-up were included (1 died; 23 were lost follow-up): 22 males, 2 females; a mean age at surgery, 30 years (range, 18-52 years); a mean follow-up of 8 years (range, 5-11 years). The mean preoperative glenoid bone defect was 22% (range, 20%-28%). All shoulders had a Hill-Sachs lesion including 4 on-track lesions. One shoulder experienced traumatic redislocation at 5 years after surgery. The scores significantly improved: Rowe score, 19 ± 8 to 94 ± 8 (P < .001); WOSI, 1547 ± 241 to 439 ± 318 (P < .001). Postoperative flexion showed significant improvement from 158 ± 18 to 169 ± 11 (P = .008), whereas internal rotation deteriorated from T8 ± 3 to T10 ± 3 (P = .005). Graft integration showed remodeling in 54% and excessive absorption in 13%. Osteoarthritis grades progressed significantly (P < .001), but only grade 1 osteoarthritic changes were seen, except for 4 shoulders with grade 2 osteoarthritis. CONCLUSIONS: Arthroscopic iliac bone grafting for traumatic anterior shoulder instability with severe glenoid bone loss yielded satisfactory outcomes with mid-term follow-up. Arthritic changes progressed in half of the shoulders; however, most shoulders only demonstrated grade 1 osteoarthritis. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Incidence of Axillary Nerve Injury After Arthroscopic Shoulder Stabilization.

PURPOSE: To investigate the incidence of axillary nerve palsy after arthroscopic shoulder stabilization and to measure the distance between the nerve and capsule in shoulders with a capsular lesion. METHODS: This retrospective study included 2,027 shoulders (1,909 patients; 1,433 male and 476 female patients; mean age, 32 years [age range, 13-81 years]) subjected to arthroscopic soft-tissue stabilization for recurrent shoulder instability from 2005 to 2017. The exclusion criteria were bone grafting or transfer and preoperative axillary nerve symptoms. We retrospectively reviewed patient records and investigated the incidence and clinical features of axillary nerve palsy. We measured the closest distance between the axillary nerve and capsule on preoperative magnetic resonance images. RESULTS: Postoperative axillary nerve palsy occurred in 4 shoulders (0.2% of all arthroscopic stabilizations). Capsular repair was performed in 2 shoulders (1.2% of 160 capsular repairs); humeral avulsion of the glenohumeral ligament (HAGL) repair, 1 shoulder (2% of 47 HAGL repairs); and isolated Bankart repair, 1 shoulder (0.05% of 1,941 Bankart repairs). The closest distance between the nerve and capsule was 3.4 ± 3.2 mm in shoulders with capsular or HAGL lesions and less than 1 mm in the 3 shoulders with palsy. The common symptoms in axillary nerve palsy cases were shoulder discomfort, delayed recovery of range of motion, and deltoid weakness and atrophy. A definitive diagnosis was made with electromyography in all cases. Nerve injury by a suture was confirmed during revision surgery in 3 shoulders subjected to capsular or HAGL repair during the initial operation. The palsy was transient and fully recovered in 1 shoulder with isolated Bankart repair. CONCLUSIONS: The incidence of axillary nerve palsy after arthroscopic soft-tissue shoulder stabilization was low but higher in shoulders subjected to capsular or HAGL repair. We should always consider the possibility of axillary nerve palsy in shoulders that require capsular or HAGL repair. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Relationship between postoperative retear and preoperative fatty degeneration in large and massive rotator cuff tears: quantitative analysis using T2 mapping.

BACKGROUND: Fatty degeneration of the rotator cuff muscles is reported to be associated with retear after rotator cuff repair. The purpose of this study was to assess the relationship between retear and preoperative fatty degeneration, as quantified by T2 mapping. METHODS: This prospective cohort study included 83 large and 24 massive rotator cuff tears (average age, 67 years; range, 46-82 years). All patients preoperatively underwent T2 mapping magnetic resonance imaging, and T2 values of the supraspinatus and infraspinatus muscles were quantified. Cuff integrity was evaluated with magnetic resonance imaging 1 year postoperatively. Preoperative T2 values were compared between the retear and intact groups. The preoperative Goutallier stage, Constant score, and the shoulder score of the University of California at Los Angeles were also compared between the 2 groups. RESULTS: Retear was found in 32 shoulders (30%). Postoperative Constant and University of California at Los Angeles scores were significantly higher in intact shoulders than in retear shoulders (P < .001 for both). Mean preoperative T2 values of supraspinatus and infraspinatus were 77.4 ± 13.2 ms and 73.2 ± 15.3 ms in retear shoulders and 66.5 ± 11.1 ms and 58.6 ± 11.7 ms in intact shoulders, respectively; the differences were significant in both muscles (P < .001). Cutoff values for prediction of retear were 71.8 ms in supraspinatus and 63.1 ms in infraspinatus. There were no significant differences in the preoperative Goutallier stages of supraspinatus and infraspinatus between the 2 groups. CONCLUSIONS: Retear shoulders demonstrated significantly higher preoperative T2 values than intact shoulders. T2 mapping can be a useful tool for predicting postoperative retears.

Three-dimensional measurement of glenoid dimensions and orientations.

BACKGROUND: Asians generally have smaller stature than Europeans and Americans, and currently available implants used in reverse shoulder arthroplasty might not fit smaller bony anatomies. However, few articles have reported glenoid geometry in the Asian population. The purpose of this study was to measure the dimensions and orientations of the glenoid from three-dimensional computed tomography reconstructions of elderly Japanese subjects. METHODS: This study included 100 shoulders (50 males and 50 females with >50 years of age). The mean age was 67 ± 7 years for both sexes, and the mean height was 167 ± 7 cm for males and 154 ± 6 cm for females. Three-dimensional scapular models were created from computed tomographic images, and the glenoid height, glenoid width, glenoid version, glenoid inclination, vault depth, and vault width were measured. RESULTS: The mean glenoid height and width were 38.6 and 29.4 mm for males and 33.1 and 24.4 mm for females, respectively. Both retroversion and superior inclination were approximately 3° in both sexes. The glenoid vault was deeper in the posterior region with the maximum depth of 26.1 and 23.6 mm in males and females. The vault width was narrower in the anterior region with the anterior width of 2.5 mm at 15 mm medial from the glenoid face in females. CONCLUSION: Glenoids of Japanese females are small compared to currently available baseplates for reverse shoulder arthroplasty. These results may be helpful to aid design in smaller baseplates that better fit the anatomic geometry of the Asian glenoid.

Medial elbow anatomy: A paradigm shift for UCL injury prevention and management.

To improve the management outcomes and diagnostic accuracy of the ulnar collateral ligament (UCL) injury, the anatomy of the medial side of the elbow joint is necessary to be understood in terms of the periarticular surroundings rather than the specific ligaments. The aim of this study was to anatomically clarify the medial side of the elbow joint in terms of the tendinous structures and joint capsule. We conducted a descriptive anatomical study of 23 embalmed cadaveric elbows. We macroscopically analyzed the relationship between the flexor pronator muscles (FPMs) and the joint capsule in 10 elbows, histologically analyzed in 6 elbows, and observed the bone morphology through micro computed tomography in 7 elbows. The two tendinous septa (TS) were found: between the pronator teres (PT) and flexor digitorum superficial (FDS) muscles, and between the FDS and flexor carpi ulnaris (FCU) muscles. These two TS are connected to the medial part of the brachialis tendon, deep aponeurosis of the FDS, and FCU to form the tendinous complex, which linked the humeroulnar joint and could not be histologically separated from each other. Moreover, the capsule of the humeroulnar joint under the tendinous complex had attachment on the ST of 7 mm width. The two TS, the brachialis tendon, the deep FDS and FCU aponeuroses, and the joint capsule linked the humeroulnar joint. These anatomical findings could lead to a paradigm shift in the prevention, diagnosis, and treatment of UCL injuries in baseball players. Clin. Anat. 32:379-389, 2019. © 2018 The Authors. Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.

Progression of degenerative changes of the biceps tendon after successful rotator cuff repair.

BACKGROUND: This study investigated the morphologic changes in the biceps tendon using ultrasonography before and after successful arthroscopic posterosuperior rotator cuff repair. METHODS: Forty-four patients (44 shoulders) underwent arthroscopic posterosuperior rotator cuff repair with 1-year postoperative magnetic resonance imaging (MRI) follow-up. The patients comprised 22 men and 22 women with an average age of 61 years. The cross-sectional area (CSA) of the biceps tendon in the bicipital groove was measured, and the vascularity in the bicipital groove was graded as 0 to 3, based on the signal density of the anterior circumflex artery, using power Doppler ultrasonography. The preoperative and postoperative CSA and vascularity grades were compared. The pain score on the University of California, Los Angeles Shoulder Rating Scale was used to analyze the correlation between vascularity and postoperative pain. RESULTS: The average preoperative and postoperative CSA of the biceps tendon was 15.4 ± 6.5 and 17.9 ± 7.5 mm2, respectively. The postoperative CSA was significantly larger than the preoperative CSA (P < .01). Although no significant difference in the vascularity of the bicipital groove was observed between preoperative and postoperative grading, a negative correlation was observed between the vascularity and postoperative pain score on the University of California, Los Angeles scale (r = -0.369). CONCLUSIONS: The biceps tendon in the bicipital groove becomes thicker over time, even after successful posterosuperior rotator cuff repair. In addition, an increase in the vascularity around the biceps tendon in the groove is correlated with pain symptoms after successful repair.

Differences in fatty degeneration of rotator cuff muscles at different sites, as quantified by T2 mapping.

BACKGROUND: Fatty degeneration of the cuff muscles is usually evaluated at the Y-view in oblique sagittal images. It was recently proposed that muscle shift after repair may influence the fatty degeneration values, and the evaluation of the muscles at a more medial site was recommended. However, the differences in muscle quality in accord with measurement sites have been unclear. Here we evaluated differences in fatty degeneration of the rotator cuff muscles measured quantitatively at different sites, using T2 mapping. METHODS: We assessed 702 shoulders of 675 patients (335 males, 340 females; mean age, 62 years) who underwent MRI including T2 mapping. There were 345 shoulders without rotator cuff tears and 357 shoulders with tears: partial tear = 103 shoulders; small = 63; medium = 94; large = 71; massive = 26. T2 values of the supraspinatus and infraspinatus muscles were measured on the Y-view and on the image that was 15 mm medial to the Y-view. RESULTS: The T2 values at the medial site increased with the tear extent, as did those on the Y-view. There were no significant differences in supraspinatus T2 values between those on the Y-view and at the medial site in all tear size groups except medium and large tears (p = 0.008 and p < 0.001, respectively). There were also no significant differences in infraspinatus T2 values between the two sites in all tear size groups except large tears (p = 0.002). However, the differences were relatively small (2.4-5.6 ms), which were within the standard deviations of the measurements. CONCLUSIONS: The T2 values of the supraspinatus and infraspinatus muscles on the Y-view and at 15 mm medial to it were almost identical, with the exception of small differences in the case of larger tears.

Fatty Degeneration of the Rotator Cuff Muscles Improves in Shoulders with Successful Arthroscopic Rotator Cuff Repair: A Prospective Study Using Quantitative T2 Mapping Techniques, with 2-Year Follow-up.

Background: There remain arguments regarding whether fatty degeneration of the rotator cuff muscles improves following rotator cuff repair. The purpose of this study was to prospectively investigate changes in fatty degeneration of the rotator cuff muscles, quantitatively measured on magnetic resonance imaging (MRI) with use of transverse relaxation time (T2) mapping techniques, and to assess the relationship between these changes and clinical outcomes. Methods: Patients were included if they were scheduled for arthroscopic rotator cuff repair using the suture-bridge technique between June 2014 and December 2015, underwent preoperative MRI including the T2 mapping sequence, and consented to participate in the study. Exclusion criteria consisted of trauma within 2 months before preoperative MRI, isolated subscapularis tears, patch augmentation, neuromuscular disease, and a follow-up duration of <2 years. MRI scans were acquired preoperatively and at 2 years postoperatively, and T2 values of the supraspinatus and infraspinatus muscles were measured, with smaller T2 values indicating less fat content. Shoulders were evaluated on the basis of active range of motion (ROM), Constant and University of California Los Angeles Shoulder Rating Scale scores, shoulder external rotation strength with the arm at the side, and rotator cuff integrity on postoperative MRI. Results: A total of 103 patients (103 shoulders) with a mean age of 65 ± 9 years (range, 42 to 83 years) were included, of whom 52 were male and 51 were female. There were 13 partial, 18 small, 35 medium, 33 large, and 4 massive tears. Concomitant subscapularis tears were observed in 35 shoulders. Overall, ROM, clinical scores, and external rotation strength significantly improved postoperatively. Retears were found in 27 shoulders (26%). External rotation strength significantly improved postoperatively only in shoulders without a retear. Among shoulders without a retear, the postoperative T2 values of the supraspinatus and infraspinatus were significantly smaller than the preoperative values (p < 0.001 for both); however, no improvement was seen in shoulders with a retear. Conclusions: Shoulders with successful repair demonstrated significantly smaller T2 values postoperatively as well as significantly improved external rotation strength. Fatty degeneration of the cuff muscles can be reversed, at least in part, and muscle strength improves in shoulders with successful repair. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Microscopic Magnetic Resonance Imaging Comparing Asymptomatic and Symptomatic Ulnar Collateral Ligament Injuries in Baseball Players.

BACKGROUND: The relationship between abnormalities of the ulnar collateral ligament (UCL) on magnetic resonance imaging (MRI) and elbow symptoms in baseball players remains unclear. PURPOSE/HYPOTHESIS: This study aimed to compare findings of the UCL on microscopic MRI between asymptomatic and symptomatic elbows in baseball players. We hypothesized that the MRI grade of UCL injuries would exhibit no correlation with medial elbow symptoms in baseball players. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: The study participants were skeletally mature baseball players who underwent high-resolution microscopic MRI of the medial elbow including for medical checkups. Elbows with previous surgical treatment or traumatic UCL injuries were excluded. The patients were divided into symptomatic and asymptomatic groups. The UCL appearance on microscopic MRI was categorized into 4 grades and compared between the groups. Abnormal findings in the medial elbow including bony fragments at the medial epicondyle, osteophytes or bony fragments in the sublime tubercle, and bone marrow edema (BME) in the sublime tubercle were also evaluated. RESULTS: A total of 426 baseball players (426 elbows) with a mean age of 20 years (range, 14-41 years) were included. The asymptomatic and symptomatic groups included 158 and 268 elbows, respectively. In the asymptomatic group, based on MRI grading of the UCL, 46 (29%) elbows were rated as grade I, 64 (41%) as grade II, 40 (25%) as grade III, and 8 (5%) as grade IV. In the symptomatic group, 75 (28%) elbows were rated as grade I, 118 (44%) as grade II, 61 (23%) as grade III, and 14 (5%) as grade IV. There was no significant difference in the MRI grades between the groups (P = .9). BME in the sublime tubercle was more frequently seen in the symptomatic group than in the asymptomatic group (P < .001). CONCLUSION: There was no difference in MRI grades of the UCL between symptomatic and asymptomatic elbows in baseball players; approximately 30% of elbows demonstrated high-grade UCL injuries in both groups. BME in the sublime tubercle was more frequently seen in symptomatic elbows than in asymptomatic elbows. BME in the sublime tubercle was a better indicator of symptoms than was MRI grading of the UCL.

Elbow anatomy in perspective of joint capsule and surrounding aponeuroses: a narrative review.

Background: Because of the proximity of several ligaments, aponeuroses, and capsule in the limited area of the elbow joint, the precise anatomy is difficult to understand. In the current narrative review, we focused on two anatomical perspectives: the capsular attachment and structures consisting of ligaments. Methods: Based on the previously performed studies regarding the elbow anatomy, a narrative review was prepared in terms of the capsular attachment and structures consisting of ligaments. Results: At the tip of the coronoid process, the joint capsule attaches roughly 6 mm distal to its tip with 6-12 mm length. On the lateral epicondyle of the humerus, the capsular attachment at the anterior part of the extensor carpi radialis brevis origin is narrower than the one distal to it. A single interpretation of the lateral collateral ligament is the capsulo-aponeurotic membrane, which is composed of the joint capsule intermingling with the supinator aponeurosis. The anterior bundle of the ulnar collateral ligament could be interpreted as the grossly separated collagenous structure from the tendinous complex, which is composed of the tendinous septum between the flexor digitorum superficialis and pronator teres muscle, the medial part of the brachialis muscle, and deep aponeurosis of the flexor digitorum superficialis muscle. Discussion: Based on these perspectives, ligaments could function as a "static-dynamic" stabilizer rather than a simple static one.

Elasticity assessment of flexor pronator muscles using shear wave elastography.

Background: The flexor pronator muscles (FPMs) have been thought as a dynamic stabilizer to protect the ulnar collateral ligament (UCL) from valgus stress during throwing motion. Thus, evaluation of the FPMs is important for preventing UCL injuries. Shear wave ultrasound elastography (SWE) is an imaging modality that quantifies tissue elasticity. The purpose of this study was to measure the tissue elasticities of healthy FPMs using SWE. Methods: We investigated 22 healthy men (mean age, 29 ± 6 years). The elasticities of the FPMs, including the pronator teres (PT), flexor digitorum superficialis (FDS), and flexor carpi ulnaris (FCU), were measured using SWE for each arm under two conditions: at rest (unloaded) and under valgus stress (loaded). The values obtained under different loading conditions were compared between both elbows. Results: The mean SWE values of the PT, FDS, and FCU for the dominant elbows were 22.4 ± 3.6, 22.8 ± 2.9, and 22.3 ± 3.4 kPa, respectively. The corresponding mean SWE values for the nondominant elbows were 24.2 ± 4.6, 23.1 ± 3.5, and 23.4 ± 3.5 kPa, respectively. The mean SWE values of the PT, FDS, and FCU at rest (unloaded) were 23.3 ± 4.2, 22.9 ± 3.2, and 22.9 ± 3.5 kPa, respectively. The corresponding mean SWE values under valgus stress (loaded) were 35.0 ± 6.2, 34.7 ± 5.3, and 31.9 ± 4.8 kPa, respectively. Conclusion: This noninvasive evaluation of the stiffness of the FPMs may provide clinically relevant data for the prevention of UCL injuries.

Below- or above-elbow immobilization in conservative treatment of distal radius fractures: a systematic review and meta-analysis.

INTRODUCTION: There is no consensus regarding the range of immobilization in the conservative treatment of distal radius fractures (DRFs). Therefore, this systematic review and meta-analysis aimed to compare the clinical outcome of patients with DRFs treated conservatively with below- or above-elbow immobilization. MATERIALS AND METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, two independent reviewers searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov and World Health Organization International Clinical Trials Registry Platform in April 2020; a subsequent update search was conducted in April 2021. We identified all randomised controlled trials comparing two immobilization methods in DRFs. The primary outcome measures were the Disabilities of the Arm, Shoulder and Hand (DASH) or QuickDASH questionnaire scores in the short- and long-term (≤ and >six weeks, respectively) follow-up as well as the treatment failure rate. The secondary outcome measures were radiographic outcome, patient-rated wrist evaluation (PRWE) score, pain score and adverse events. Risk of bias was evaluated using the Cochrane Risk of Bias tool version 2. We used the Grading of Recommendations Assessment, Development and Evaluation approach to evaluate the quality of evidence. RESULTS: The initial search revealed 1,775 records, and ten studies with 909 participants in total were included. There was no significant difference in DASH score in the short-term follow-up (4.99 lower, 95% confidence interval (CI): 10.45 lower to 0.46 higher; very low certainty) and treatment failure (risk ratio: 0.91, 95% CI: 0.59 to 1.40; low certainty). A clinically irrelevant but significant mean difference (0.83 lower, 95%CI: 1.64 lower to 0.03 lower; low certainty) was found in the DASH score in favour of below-elbow immobilization in the long-term follow-up. The overall risk of bias in DASH scores was high based on the measurement bias. Furthermore, there was no significant difference in secondary outcome measures. CONCLUSION: This meta-analysis did not demonstrate clinically meaningful difference between below- and above-elbow immobilization in terms of DASH score both in the short- and long-term follow-ups. However, overall certainty of evidence was considered very low, based on the very serious risk of bias, inconsistency and imprecision. Hence, there is a need for further higher quality research. TRIAL REGISTRATION NUMBER: UMIN000040134 (4/14/2020).

Pathology and surgical outcomes of unstable painful shoulders.

Background: Boileau et al have reported on the unstable, painful shoulder (UPS), which was defined as painful shoulders without any recognized anteroinferior subluxations or dislocations that were associated with roll-over lesions (ie, instability lesions) on imaging or at arthroscopy. However, they included various pathologies, probably due to the ambiguity in their definitions of UPS. We redefined UPS as follows: (1) shoulder pain during daily or sports activities, (2) traumatic onset, (3) no complaint of shoulder instability, and (4) soft-tissue or bony lesions, such as Bankart or humeral avulsion of glenohumeral ligament lesion, confirmed by arthroscopy. The purpose of this study was to retrospectively investigate pathologies of UPS based on our definitions. We also aimed to assess the outcomes after arthroscopic soft-tissue stabilization for UPS. Methods: We reviewed patients who were retrospectively diagnosed as UPS based on our definition and underwent arthroscopic stabilization between January 2007 and September 2018. Patients' demographics, physical and radiographic findings, intraoperative findings, clinical outcomes (Rowe scores, Subjective Shoulder Value [SSV], and the visual analog scale [VAS] for pain), and return to play sport (RTPS) were investigated. Results: This study included 91 shoulders in 91 patients with a mean age of 23 years (range, 15-51). The mean follow-up was 37 months (range, 24-156). Eighty-seven patients were involved in sports activities: collision/contact, 55 patients (60%); overhead, 26 patients (29%). The pain was reproduced during the anterior apprehension test in 86 shoulders (95%). Normal type (49%) predominated in glenoid morphology followed by fragment (bony Bankart) type (37%). Most fragment-type lesions were seen in collision/contact athletes. Intraoperative findings demonstrated that Bankart lesions were found in all patients and Hill-Sachs lesions only in 42%. Magnetic resonance arthrography in the abducted and externally rotated positions showed a Bankart lesion in 76 shoulders (84%). Rowe score, SSV, and pain VAS significantly improved postoperatively (P < .001 for each). Forty-two of 70 athletes (60 %) with > 2-year follow-up returned to the sport at a complete or near-preinjury level. Six (9%) athletes experienced reinjury. Conclusion: All shoulders that were diagnosed as UPS with our definition had a Bankart lesion. There seemed to be two different types of pathologies: Bankart lesions in lax shoulders and bony Bankart lesions in collision/contact athletes. The pain experienced during the anterior apprehension test may be useful for the diagnosis of UPS. Arthroscopic soft-tissue stabilization yielded good clinical outcomes with a high RTPS rate, but the reinjury rate was relatively high.

Arthroscopic Repair of Isolated Subscapularis Tears Show Clinical and Structural Outcome Better for Small Tears Than Larger Tears.

Purpose: To retrospectively investigate the mid-term outcomes after arthroscopic repair of isolated subscapularis tears with a relatively large number of patients and to compare them by tear size. Methods: Medical records were reviewed for patients who underwent arthroscopic rotator cuff repair between 2010 and 2017 at our institute. The inclusion criterion was isolated subscapularis tears that underwent arthroscopic rotator cuff repair. The exclusion criteria were (1) previous rotator cuff surgery, (2) lack of imaging studies or clinical evaluation data, (3) neuromuscular diseases, and (4) <2-year follow-up. Range of motion, American Shoulder and Elbow Society score, and bear-hug or belly-press test were assessed pre- and postoperatively. Repair integrity was evaluated with magnetic resonance imaging at postoperative1 year. The clinical and imaging study outcomes were compared between smaller (Lafosse types 1-3) and larger (types 4 and 5) tears. Results: The subjects included 38 males and 8 females with a mean age of 59 years (range, 25-77 years). The mean follow-up was 36 months (range, 24-96 months). There were 13 type 1, 10 type 2, 12 type 3, 6 type 4, and 5 type 5 shoulders. Postoperative American Shoulder and Elbow Society scores were significantly better in smaller tears than larger tears: 93 ± 8 and 75 ± 14, respectively (P = .003). Smaller tears showed better postoperative internal rotation than larger tears (P = .004). Significant decrease of positive bear-hug or belly-press test was observed in smaller tears (preoperative, 25; postoperative, 11; P < .001), but there was no significant improvement in larger tears (preoperative, 11; postoperative, 9). The retear rate was significantly greater in larger tears (64%) than smaller tears (6%, P < .001). Conclusions: The clinical and structural outcomes after arthroscopic repair of isolated subscapularis tears were better in smaller tears than larger tears with a mid-term follow-up. Larger tears showed high retear rates with poorer improvement in active range of internal rotation and subscapularis strength. Level of Evidence: Level III, retrospective, comparative study.

Incidence of teres minor muscle atrophy in young and middle-aged populations.

Background: Teres minor atrophy can be seen in shoulders both with and without a rotator cuff tear, even among the young population. The purpose of this study was to retrospectively investigate the incidence of teres minor atrophy in young and middle-aged patients with or without a rotator cuff tear. Methods: Patient records were reviewed to identify 10-39-year-old patients (Group Y) and 60-69-year-old patients (Group O) who underwent MRI because of shoulder disorders. The exclusion criteria were as follows: (1) prior surgeries, (2) neurological disorders in the cervical spines or shoulder girdle, (3) global atrophy of all four cuff muscles without a rotator cuff tear, (4) acute trauma, and (5) poor image quality due to artifacts. An experienced shoulder surgeon evaluated teres minor atrophy on T1-weighted oblique sagittal images. Statistical analysis was performed using the chi-square test for comparison of Groups Y and O. Results: Group Y consisted of 528 shoulders in 520 patients, including 406 males and 114 females with a mean age of 26 years. Group O consisted of 884 shoulders in 837 patients, including 394 males and 443 females with a mean age of 65 years. Rotator cuff tears were seen in 33 shoulders (6.3 %) in Group Y, and 411 shoulders (46.5%) in Group O. Teres minor atrophy was more present in Group O (59 shoulders [6.7%]) than Group Y (11 shoulders [2.1%], P < .001). Among shoulders with teres minor atrophy, the incidence of intact cuff tended to be higher in Group Y than O (7 shoulders [64%] and 21 shoulders [36%], P = .08). However, the ratio of the intact cuff to the number of patients in each group was not significantly different (Group Y, 7 of 528 [1.3%]; Group O, 21 of 884 [2.3%]). Teres minor muscle atrophy tended to be more common in athletes than nonathletes in Group Y, although the difference was not significant (P = .057). Conclusion: The incidence of teres minor atrophy was significantly higher in middle-aged patients than young patients. Middle-aged patients with teres minor atrophy were more associated with rotator cuff tears. The common cause of teres minor atrophy may be rotator cuff tears. Teres minor atrophy in young patients might be associated with sports-related factors such as infraspinatus hypertrophy or axillary nerve injury.

Three-dimensional kinematics of reverse shoulder arthroplasty: a comparison between shoulders with good or poor elevation.

BACKGROUND: Various factors may be related to outcomes of reverse shoulder arthroplasty (RSA) including patient and surgical factors. Differences in shoulder kinematics might be associated with poor function after RSA; however, kinematic differences between shoulders with good or poor elevation have not been elucidated. The purpose of this study was to compare RSA kinematics between shoulders with good or poor elevation. METHODS: The study included 28 shoulders with a minimum 6-month follow-up after RSA using Grammont-type prostheses. Subjects comprised 17 men and 11 women with the mean age of 75 years (range, 63-91). Subjects underwent fluoroscopy during active scapular plane abduction. Computed tomography of their shoulders was performed to create 3-dimensional scapular implant models. Using model-image registration techniques, poses of 3-dimensional implant models were iteratively adjusted to match their silhouettes with the silhouettes in the fluoroscopic images, and 3-dimensional kinematics of implants were computed. Kinematics and glenosphere orientation were compared between shoulders with good (>90 degree) or poor (<90 degree) scapular plane abduction. RESULTS: Nineteen and 9 shoulders were assigned to the good- and poor-elevation groups, respectively. There were no significant differences between the groups in age, sex, height, weight, preoperative range of motion, or Constant score, but body mass index in the poor elevation shoulders was significantly larger than that in the good elevation shoulders. There were no significant differences in glenosphere (upward/downward rotation, anterior/posterior tilt, internal/external rotation) or glenohumeral (internal/external rotation, abduction/adduction) kinematics between the good and poor elevation shoulders. Scapulohumeral rhythm was significantly higher in the good elevation shoulders than the poor elevation shoulders (P = .04). Glenosphere superior tilt was 2.3° ± 4.2° in the good-elevation group and 8.1° ± 8.9° in the poor-elevation group, and the difference was statistically significant (P = .03). DISCUSSION: Shoulders with good elevation after RSA demonstrated better scapulohumeral rhythm than those with poor elevation, though there were no significant differences in glenosphere and glenohumeral kinematics. It may be important for better elevation to achieve good glenohumeral motion in shoulders with RSA. Glenosphere orientations may affect postoperative shoulder function.

Validation study of novel grading system for ulnar collateral ligament injury of the elbow with high-resolution magnetic resonance imaging.

BACKGROUND: Recently, magnetic resonance imaging (MRI) classification of medial ulnar collateral ligament (UCL) tears has been introduced, but little is known about the relationship between MRI grading and medial joint laxity. It has been reported that microscopy coils could make it possible to achieve high-resolution images of upper extremities with a superior diagnostic ability to conventional MRI. However, there is no report that has compared the diagnostic reliability between microscopic and conventional MRI. The purpose of this study was to assess the relationship between MRI findings and medial joint laxity evaluated with stress ultrasound (US). Secondary objective was to compare the reliabilities of UCL evaluation between microscopic and conventional MRI. METHODS: One-hundred thirty baseball players who underwent MRI of the elbow for the diagnosis of UCL injury using both conventional and microscopy MRI were included in this study. They also underwent stress US for assessment of medial joint laxity against valgus stress. Our MRI grading system for UCL injuries was compared to medial joint laxity evaluated with stress US. The intrarater and interrater reliabilities of our grading system were assessed with both microscopic and conventional MRI. RESULTS: Our grading system was related to valgus stability, especially with microscopic MRI. The reliabilities were fair when combined with microscopic MRI, which exhibited better intrarater and interrater reliabilities than conventional MRI. CONCLUSION: High-resolution microscopic MRI may contribute to the accurate diagnosis of UCL injuries.

Arthroscopic Soft Tissue Stabilization With Selective Augmentations for Traumatic Anterior Shoulder Instability in Competitive Collision Athletes.

BACKGROUND: Many surgeons prefer bony stabilization including Bristow or Latarjet procedures for shoulder instability in collision athletes, even though several potential complications have been reported. There has been a limited number of studies on the midterm outcomes of arthroscopic soft tissue stabilization for anterior shoulder instability in competitive collision athletes. PURPOSE: To assess the outcomes of arthroscopic soft tissue stabilization in combination with selective augmentation procedures for collision athletes with traumatic anterior shoulder instability. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We retrospectively assessed rugby or American football players (<40 years old) who underwent arthroscopic Bankart or bony Bankart repair with selective augmentations (rotator interval closure and/or Hill-Sachs remplissage) for traumatic anterior shoulder instability between January 2012 and March 2017. Shoulders that required other bony procedures were excluded. Recurrence, complications, return to sport, and functional scores (Rowe score and Subjective Shoulder Value sports score) were investigated. RESULTS: This study included 113 shoulders in 100 patients with a mean age of 20 years (range, 15-36 years) at surgery. Rotator interval closure was performed on 36 shoulders in addition to Bankart repair, and rotator interval closure and Hill-Sachs remplissage were performed on 77 shoulders. The mean follow-up period was 44 months (range, 24-72 months). Of the 113 shoulders, 4 (3.5%) experienced postoperative dislocation, but there were no complications. A total of 93 athletes (93%) attained complete or near complete preinjury sports activity levels. The mean Rowe score significantly improved from 36 (range, 10-75) at presurgery to 96 (range, 35-100; P = .003) at postsurgery. The mean Subjective Shoulder Value sports score significantly improved after surgery, from a mean preoperative score of 22 (range, 0-50) to a postoperative score of 92 (range, 64-100; P = .002). CONCLUSION: Our treatment strategy, where arthroscopic soft tissue stabilization was combined with selected augmentations, provided good clinical outcomes for competitive collision athletes in terms of low rates of recurrence and complication, a high rate of return to sports, and good shoulder function.