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.

Return to sports and physical work after anatomical and reverse shoulder arthroplasty.

BACKGROUND: No consensus has been reached on the return to sports or physical work after shoulder arthroplasty due to a shortage of literature. The purpose of this study was to investigate return to sports or physical work after anatomical total shoulder arthroplasty (aTSA) and reverse shoulder arthroplasty (RSA), as well as the clinical and radiographic outcomes. METHODS: The inclusion criteria were as follows: 1) aTSA or RSA between 2012 and 2017, and 2) patients who preoperatively participated in sports or physical work. The exclusion criteria were as follows: 1) revision arthroplasty, 2) fracture/dislocation, 3) fracture sequelae, 4) postinfection, and 5) <2-year follow-up. Sports and physical work were classified as low-, medium-, or high-load activities. Range of motion, Constant score, sport or work return, and radiographic findings were evaluated and compared between aTSA and RSA groups. RESULTS: The subjects who met the criteria were 90 shoulders in 86 patients. The aTSA group consisted of 30 shoulders (10 men and 20 women) with a mean age of 71 ± 8 years (range, 56-85). The RSA group consisted of 60 shoulders (39 men and 21 women) with a mean age of 72 ± 6 years (range, 56-83). Active range of motion significantly improved after surgery in all directions in the aTSA group but only in flexion and external rotation in the RSA group. Postoperative external and internal rotations, as well as postoperative Constant scores and satisfaction, were significantly better in the aTSA than in the RSA group. In the aTSA group, the return rate was 93%, and the complete return rate was 70%. In the RSA group, the return rate was 83%, and the complete return rate was 30%. The complete return rate was significantly higher in the aTSA than in the RSA group. Only one aTSA shoulder showed loosening of the glenoid implant, and 8 RSA shoulders demonstrated low-grade scapular notching. CONCLUSION: The return to sports or physical work rates after aTSA and RSA were high; however, the complete return rates were significantly higher in the aTSA group than in the RSA group. No radiographic failures were identified except for one asymptomatic glenoid loosening with a midterm follow-up.

Biceps tenotomy versus soft-tissue tenodesis in females aged 60 years and older with rotator cuff tears.

BACKGROUND: Recently, to treat the long head of the biceps tendon lesions in addition to rotator cuff repair has been recommended. However, the differences in clinical outcomes between biceps tenotomy and tenodesis for middle-aged and elderly females remains unclear. The purpose of this study was to compare the outcomes of biceps tenotomy and soft-tissue tenodesis that were performed concurrently with arthroscopic rotator cuff repair in ≥60-year-old females. METHODS: Female shoulders that underwent arthroscopic rotator cuff repair in our institute in 2016 were retrospectively reviewed. This study included 66 shoulders with concurrent biceps tenotomy or soft-tissue tenodesis: tenotomy group, 41 shoulders; soft-tissue tenodesis group, 25 shoulders. Clinical scores, biceps pain (visual analogue scale, VAS), Popeye deformity, and biceps strength (%contralateral side) were compared between the two groups. RESULTS: The mean age was significantly higher in the tenotomy group than the soft-tissue tenodesis group (72 ± 4 and 68 ± 6 years, respectively; P = 0.002). There were no significant differences in post-operative JOA and UCLA scores between the groups. VAS for biceps pain was significantly higher at postoperative 6 months in the tenotomy group than the soft-tissue tenodesis group (2.9 ± 2.5 and 1.7 ± 1.6, respectively, P = 0.03), though there were no significant differences at postoperative 3, 12, and ≥24 months. Subjective evaluation of Popeye deformity was not significantly different between the groups. Postoperative biceps strength was significantly lower in the tenotomy group than the soft-tissue tenodesis group (89.9% and 102.8%, respectively, P = 0.02). CONCLUSIONS: Both biceps tenotomy and soft-tissue tenodesis concurrent with rotator cuff repair in ≥60-year-old female patients resulted in good outcomes. Shoulders with soft-tissue tenodesis demonstrated earlier improvement in postoperative biceps pain and better postoperative biceps strength than those with tenotomy. There were no differences in objective and subjective Popeye deformity between tenotomy and soft-tissue tenodesis. The LHB procedures, tenotomy or tenodesis, can be selected depending on surgeons' preference.

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.

Repair Integrity and Functional Outcomes After Arthroscopic Suture Bridge Subscapularis Tendon Repair.

PURPOSE: This retrospective study aimed to report repair integrity and clinical outcomes after arthroscopic suture bridge subscapularis (SSC) tendon repair. METHODS: The subjects included 101 shoulders subjected to arthroscopic suture bridge repair for full-thickness SSC tear with a minimum of a 2-year follow-up. There were 57 men and 44 women with a mean age of 66 years (range, 32-85 years). The mean follow-up was 30 months (range, 24-71 months). Tenotomy or tenodesis was performed for the long head of the biceps in all cases. All patients were assessed for active range of motion; belly-press and bear-hug tests; University of California, Los Angeles score; and American Shoulder and Elbow Surgeons score preoperatively and at the final follow-up. Repair integrity and fatty degeneration of the SSC muscle were evaluated with magnetic resonance imaging at a mean 14 months (range, 12-58 months) after surgery. RESULTS: Flexion, internal rotation, and both functional scores significantly improved after surgery. Retears were found in 5 shoulders (5%). The shoulders with a retear showed significantly inferior functional scores compared with the intact shoulders. Fatty degeneration was significantly improved in the intact group, whereas there was no significant improvement in the retear group. Both belly-press and bear-hug test scores significantly improved after surgery; however, weakness persisted in shoulders with higher grade preoperative fatty degeneration even after successful repair. CONCLUSIONS: Arthroscopic suture bridge repair for SSC tears yielded good clinical outcomes and a very low retear rate, even for larger tears or shoulders with higher grade fatty degeneration. Fatty degeneration of the SSC muscle improved after successful repair, although internal rotation weakness persisted in shoulders with higher grade preoperative fatty degeneration. Arthroscopic suture bridge repair is a promising procedure for treating SSC tears. LEVEL OF EVIDENCE: Level IV, case series study.

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.

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.

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.

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.

Assessment of the Preserved Biceps Tendon After Arthroscopic Rotator Cuff Repair in Patients ≤ 55 Years.

PURPOSE: We assessed hypertrophy of preserved long head of the biceps tendon (LHBT) and vascularity in the bicipital groove after arthroscopic rotator cuff repair in ≤55-year-old patients and compared postoperative pain between shoulders with or without vascularity in the bicipital groove. METHODS: Patients who underwent arthroscopic rotator cuff repair between 2015 and 2017 were reviewed. Inclusion criteria were arthroscopic rotator cuff repair and ≤55 years old. Exclusion criteria were a history of contralateral rotator cuff repair, revision surgery, partial repair or superior capsular reconstruction, shoulder dislocation or fracture, torn LHBT at surgery, LHBT tenodesis, retears, <1-year follow-up, and incomplete follow-up data. Cross-sectional area (CSA) of the LHBT and vascularity in the bicipital groove were examined preoperatively and 1 year after surgery using ultrasonography. Shoulder pain at postoperative 1 year was assessed using the pain subscore of the University of California at Los Angeles scale. The data were compared between shoulders with negative and positive vascularity. RESULTS: Fifty-seven shoulders were included in this study. There was no side-to-side difference in preoperative CSA. No difference was found between preoperative and postoperative CSA in the affected shoulders. Postoperative vascularity was identified in 28 (49%) shoulders. Mean pain score was significantly higher in the negative vascularity group than the positive vascularity group (9 and 8, respectively; P = .002). CONCLUSIONS: The preserved LHBT did not show hypertrophy 1 year after arthroscopic repair of medium-sized or smaller posterosuperior rotator cuff tear in ≤55-year-old patients. However, 49% of the shoulders postoperatively demonstrated lower-grade vascularity in the bicipital groove. Healthy LHBT can be preserved in ≤55-year-old patients with posterosuperior medium-sized or smaller rotator cuff tears. LEVEL OF EVIDENCE: III, retrospective comparative prognostic trial.

Clinical outcomes of anatomic total shoulder arthroplasty for primary shoulder osteoarthritis did not differ between elderly and younger Japanese patients.

Background: Few studies on the outcomes of anatomic total shoulder arthroplasty (aTSA) in Asian populations have been reported. In addition, approximately one-third of primary aTSA were performed for patients 80 years or older in Japan, but the indication of aTSA for the primary shoulder osteoarthritis in the elderly population remained unclear. The purposes of this study were (1) to investigate clinical outcomes of aTSA in Japanese patients with primary glenohumeral osteoarthritis and (2) to compare clinical outcomes between patients 80 years or older and 70 years or younger. We hypothesized that aTSA would yield favorable outcomes in Japanese patients and that the outcomes of aTSA in patients 80 years or older would be comparable to those 70 years or younger. Methods: Patient records were retrospectively reviewed to collect patients who underwent aTSA for glenohumeral osteoarthritis between August 2011 and September 2017. The inclusion criterion of this study was aTSA performed for glenohumeral osteoarthritis. Exclusion criteria were as follows: (1) secondary osteoarthritis, (2) revision surgery, and (3) < 24-month follow-up. Range of motion (ROM) and Constant score were evaluated, and complications were investigated. Rotator cuff integrity was assessed by ultrasonography. We compared the outcomes between patients 80 years or older and 70 years or younger. Results: Seventy-seven shoulders (72 patients) met the study criteria. There were 14 men and 58 women with a mean age of 75 years (range, 57-93 years) at the time of surgery. The mean follow-up was 40 months (range, 24-84 months). The Constant score significantly improved from preoperative 54 (range, 35-78) to postoperative 89 (range 69-100, P = .03). Range of motion also showed significant improvement after surgery: flexion, 90° (range, 60°-130°) to 140° (range, 90°-170°); external rotation at the side, from 7° (range, -10 to 60°) to 40° (range, 5°-70°); internal rotation, from buttock (range, buttock-L3) to L2 level (range, buttock-T8) (P <.001 for all). Postoperative subscapularis tendon tears were detected in 3 shoulders (5%). Complications other than rotator cuff tears were observed in 5 shoulders (6%). Postoperative Constant score and ROM significantly improved in both elderly and younger patients without significant differences. Conclusion: The clinical outcomes after aTSA in the Japanese population demonstrated significant improvements in ROM and Constant score with a low complication rate in the mid-term follow-up. aTSA should be indicated even in elderly patients because they also demonstrated comparable outcomes to younger patients.

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.

Comparison Between Osteochondral Autograft Transplantation and Arthroscopic Fragment Resection for Large Capitellar Osteochondritis Dissecans in Adolescent Athletes: A Minimum 5 Years' Follow-up.

BACKGROUND: The choice of surgical option for unstable large capitellar osteochondritis dissecans (OCD) lesions in skeletally immature athletes remains controversial. PURPOSE/HYPOTHESIS: The purpose was to investigate functional and radiographic outcomes after arthroscopic fragment resection and osteochondral autograft transplantation (OAT) for unstable large capitellar OCD lesions in skeletally immature athletes with a minimum 5 years' follow-up. We hypothesized that the outcomes after OAT for large capitellar OCD lesions would be superior to those after arthroscopic fragment resection. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 19 elbows in 19 patients (17 male and 2 females) who underwent arthroscopic resection were assigned to group 1 (mean age, 14 years [range, 13-15 years]), whereas 29 elbows in 29 patients (29 male) who underwent OAT were assigned to group 2 (mean age, 14 years [range, 13-15 years]), with the mean follow-up of 8 (range, 5-11 years) and 7 (range, 5-13 years) years, respectively. All OCD lesions were larger than one-half of the radial head diameter. Functional scores, patient satisfaction, and range of motion were compared between the groups. Radiographic changes, including superior migration, radial head enlargement, and osteoarthritis (OA) grade, were examined. RESULTS: All patients returned to sports activity. Functional scores, patient satisfaction, and flexion at the final follow-up were significantly improved in both groups compared with preoperative values, and differences were not significant between groups at the final follow-up. Extension showed a significant improvement in both groups (group 1: -17° to 0°; group 2: -18° to -6°; P < .001). Extension in group 1 was significantly better than that in group 2 at the final follow-up (P = .045). No elbows developed postoperative severe OA in group 1, whereas 3 elbows in group 2 had grade 3 OA; these 3 elbows had preoperative superior migration and radial head enlargement. CONCLUSION: No differences were observed in clinical and radiographic outcomes between patients undergoing arthroscopic fragment resection and OAT, except for elbow extension, at a minimum 5 years' follow-up. We believe that for adolescents with large capitellar OCD lesion, OAT is a good option for skeletally immature elbows and that arthroscopic fragment resection is a reliable and less invasive surgical option for relatively mature elbows.

In vivo measurement of distance between scapular neck and polyethylene insert during active external rotation in shoulders with Grammont type reverse prosthesis.

BACKGROUND: Scapular notching is a frequently observed complication after reverse shoulder arthroplasty. Impingement of the humeral plastic insert against the scapular neck is believed to be the cause of notching. There have been no in vivo studies that analyzed the positional relationship between the scapular neck and humeral insert. The purpose of this study was to measure the distance between the scapular neck and insert in shoulders with Grammont-type prostheses during active external rotation at the side. METHODS: Eighteen shoulders with Grammont-type prostheses were enrolled in this study. There were 13 males and 5 females, and the mean age at surgery was 74 years (range, 63-91). Fluoroscopic images were recorded during active external rotation at the side from maximum internal to external rotation at an average of 14 months (range, 7-24) after surgery. Implant kinematics were determined with three-dimensional models of the implants and fluoroscopic images using model-image registration techniques. Based on the implant kinematics, the closest distance between the scapular neck and insert was computed at each 5° increment of glenohumeral internal/external rotation. RESULTS: Mean glenohumeral abduction during rotation was 17°-22°. The mean distance between the neck and insert was approximately 1 mm throughout the activity. The separation distance tended to narrow with arm external rotation, but the change was not significant. INTERPRETATION: The small distance between the scapular neck and insert in early post-operative reverse shoulder arthroplasty patients may be associated with the high incidence of scapular notching in Grammont-type prostheses.