Electromyographic activities of glenohumeral joint muscles during shoulder forward flexion with isometric horizontal abduction loading.

BACKGROUND: Isometric horizontal abduction loading has been applied to improve imbalanced scapular muscle activities during shoulder exercises; however, the effect on glenohumeral joint muscle activity remains unclear. The purpose of this study was to investigate the changes in electromyographic activity of shoulder muscles during forward flexion with isometric horizontal abduction loading in healthy participants. METHODS: Thirteen healthy men were recruited for this study. Participants performed shoulder forward flexion with isometric horizontal abduction loading using an elastic band (Flex-band condition) and forward flexion without shoulder loading (Normal-flex condition). Muscle activities were evaluated while maintaining shoulder flexion at 60°, 90°, 120°, and 150° (static task) and during active shoulder flexion from 0° to maximum elevation (dynamic task). Surface electrodes were placed on the deltoid, pectoralis major, infraspinatus, and teres minor muscles to measure the activities of the shoulder muscles during each task. The muscle activities during the static task were compared using a 2-way analysis of variance with repeated measures of the 2 factors, loading condition and flexion position, and a paired t test was used for comparisons between the 2 conditions during the dynamic task (significance level set at P < .05). RESULTS: For the static task, the Flex-band condition significantly increased the deltoid middle and posterior activities by 2-15 times and the infraspinatus and teres minor activities by 2-3 times compared with the Normal-flex condition at all positions. In contrast, the Flex-band condition significantly decreased (by about half) the activities of the deltoid anterior (at 120° and 150°) and pectoralis major (at all positions) compared with the Normal-flex condition. For the dynamic task, the Flex-band condition significantly increased the deltoid middle, deltoid posterior, infraspinatus, and teres minor activities by 2-7 times and decreased the deltoid anterior activity by approximately two-thirds. CONCLUSIONS: Applying isometric horizontal abduction loading during shoulder forward flexion may be useful in improving the imbalanced muscle activities of the glenohumeral joint, such as excessive activity of the deltoid anterior and pectoralis major and dysfunction of the deltoid middle, deltoid posterior, and shoulder external rotator muscles. Shoulder forward flexion with horizontal abduction loading could be available for exercise in patients who have massive rotator cuff tears or who have undergone rotator cuff repair and shoulder arthroplasty.

Glenoid wear after humeral head replacement with using a single implant in patients with cuff tear arthropathy more than five years.

BACKGROUND: The aim of this study was to investigate glenoid wear in patients with humeral head replacement with a smaller humeral head, who were observed for >5 years, and to examine the relationship between radiographic changes and clinical outcome. METHODS: In this study, 41 shoulders of 41 patients (13 men, 28 women) were followed up for >5 years. The mean patient age at the time of surgery was 70.5 years. The average follow-up period at short-term was 26.0 months, and intermediate-term was 66.5 months. We classified glenoid wear into four grades (i.e., Grade 0 to Grade 3). Age, sex, clinical scores, and range of motion were investigated in relation to the grade of glenoid wear. Radiographs of glenoid wear evaluated in the short-term were subsequently compared to radiographs obtained in the intermediate-term period. RESULTS: At the final follow-up, 16 (39%) patients had Grade 0 wear, 11 (27%) patients had Grade 1 wear, 10 (24%) patients had Grade 2 wear, and 4 (10%) patients had Grade 3 wear. The University of California-Los Angeles score, Japanese Orthopaedic Association score, and active forward flexion were significantly lower in the Grade 3 patients; however, Grade 3 patients did not have significant pain. No significant difference in age, sex, Constant score, active external rotation, and active internal rotation in relation to the grade of glenoid wear was observed. In total, 25 (61%) patients showed a progression of glenoid wear. Cases in which glenoid wear progressed after 4 years after surgery were rare. Two patients of Grade 3 underwent total shoulder arthroplasty revision at 16 months and 38 months, respectively. CONCLUSIONS: Glenoid wear occurred in 61% of patients at 5 years follow-up. Pain of Grade 3 patients was mild, therefore, if pain is not severe, revision surgery may not be necessary.

Computed tomography revealed the correlation between radiolucency and alignment of all-polyethylene pegged glenoid component more than 10 years after total shoulder arthroplasty in the Japanese population.

BACKGROUND: Anatomical total shoulder arthroplasty (TSA) provides successful long-term outcomes but complications can occur after 10 years that require revision. Computed tomography (CT) is a useful tool for assessing radiolucent lines around the glenoid component of TSA; however, the merits of long-term post-TSA follow up with CT are unclear. The purpose of this study was to evaluate the long-term outcomes after TSA of Japanese population and to identify factors related to radiolucency around the glenoid component using CT. METHODS: A retrospective review was conducted of TSA patients who had completed at least 10 years of clinical follow up. Radiographs and CT images of the affected shoulder obtained at the last follow up were evaluated for radiolucent lines around the stem and each peg, superior inclination and retroversion of the glenoid component, subluxation index, and critical shoulder angle (CSA). Shoulder ROM, Constant-Murley score and UCLA score were compared between the preoperative and last follow up period. RESULTS: Eighteen shoulders in 16 patients met the inclusion criteria. Mean patient age was 61 years, mean follow up period was 137 months, and mean Yian CT score was 19%. CT score was significantly highest in pegs located inferiorly (p < 0.05). Mean glenoid superior inclination was 12.6°, retroversion was -0.3°, subluxation index was 46%, and CSA was 33.7°. Glenoid superior inclination was significantly lower (p = 0.007) in shoulders with possible loosening than in cases with no loosening (5.0° vs 15.6°). Mean Constant score and UCLA score improved significantly after TSA, from 25.8 to 10.7 points preoperatively to 70.1 and 28.9 points postoperatively, respectively. Mean shoulder flexion, internal rotation, and external rotation also showed improvement postoperatively. CONCLUSION: TSA provides good long-term outcomes. Radiolucency was present most frequently around the inferior pegs of the glenoid component. Glenoid superior inclination may affect the formation of radiolucent lines around glenoid pegs. LEVEL OF EVIDENCE: Level IV; Case Series; Treatment study.

Morphology of the coracoid process as a predictor of articular-side tear at the upper border of the subscapularis.

BACKGROUND: Articular-side tear at the upper border of the subscapularis (SSC-AST) is often detected during shoulder arthroscopic surgery, although its exact pathology remains unknown. The purpose of this study was to investigate the correlation between various characteristics of the coracoid process, including classification of the morphology of the coracoid process tip, and the presence of SSC-AST. METHODS: This retrospective, case-controlled study included patients who underwent arthroscopic subacromial decompression with or without rotator cuff repair between January 2018 and September 2021. A total of 130 shoulders in 124 patients, including 77 male and 53 female shoulders (mean age at surgery, 64 years [range, 39-88 years]), were included in this study. Three-dimensional (3D) computed tomography examination was performed preoperatively, and the following indices were measured: coracoid proximal length, coracoid distal length, coracoid angle, coracoglenoid angle, offset of the coracoid process and glenoid (anterior, lateral, and superior offset), and coracoid base angle. The morphology of the tip of the coracoid process was classified into 3 types according to 3D reconstructed views: flat type, round type, and beak type. The presence of SSC-AST was intraoperatively evaluated arthroscopically via a posterior glenohumeral portal. Morphologic risk factors for SSC-AST were evaluated between SSC-AST cases (group T) and non-SSC-AST cases (group N) by multivariable logistic analysis. In addition, the correlation between the incidence of SSC-AST and classification of the tip of the coracoid process was analyzed. RESULTS: SSC-AST was present in 53 shoulders (40.8%). Group T patients were significantly older than group N patients (68.4 ± 10.0 years vs. 61.5 ± 11.8 years, P < .001). No sex difference was detected between the 2 groups (28 male and 25 female shoulders in group T vs. 49 male and 28 female shoulders in group N, P = .28). Multivariate analysis of morphologic parameters between the 2 groups detected a smaller superior offset as a risk factor for SSC-AST (odds ratio, 0.91; 95% confidence interval, 0.84-0.98; P = .01). No significant differences were found in the other parameters. Regarding classification of the tip of the coracoid process, round- and beak-type coracoid tips had a significantly higher rate of SSC-AST than flat-type tips (flat type, 21.8%; round type, 64.7%; and beak type, 46.3%) (P < .001). CONCLUSIONS: Evaluation of the correlation between the morphology of the coracoid process on 3D computed tomography and the presence of SSC-AST visualized during arthroscopy indicated a significant association between SSC-AST and the morphology of the coracoid process.

Glenoid wear and its impact on clinical results after humeral head replacement using a single prosthesis in cuff tear arthropathy with more than 8 years of follow-up.

BACKGROUND: Glenoid wear (GW) is a long-term complication after humeral head replacement (HHR) and is one of the major reasons for revision surgery. This study aimed to evaluate GW at >8 years of follow-up after HHR in patients with cuff tear arthropathy (CTA) by use of a modified classification of GW, to examine the relationship between GW and clinical outcomes, and to identify risk factors for GW progression. METHODS: This retrospective case-series study included 34 shoulders that were monitored for >8 years after HHR in patients with CTA (13 men and 21 women; mean age at surgery, 70.9 years [range, 55-82 years]). Patients were monitored for a mean of 10.3 years (range, 8.1-13.2 years). GW was classified using plain radiographs as follows: grade 0, no remarkable postoperative changes; grade 1, postoperative glenohumeral joint space narrower than preoperative glenohumeral joint space; grade 2, contact between glenoid and humeral head prosthesis; and grade 3, glenoid erosion. Grade 3 cases were further classified into the following subtypes: grade 3A, partial erosion of anterior glenoid; grade 3B, partial erosion of superior glenoid; and grade 3C, concentric erosion of glenoid. Clinical outcomes including range of motion (active flexion and active external rotation) and postoperative pain (Constant score) were compared between grade 0-2 shoulders and grade 3 shoulders, as well as between the grade 3 subtypes. Age, sex, preoperative range of motion, preoperative pain, and number of ruptured tendons were analyzed as possible risk factors for progression to grade 3. RESULTS: The final GW grade was grade 0 in 3 shoulders, grade 1 in 10, grade 2 in 6, and grade 3 in 15 (grade 3A in 2, grade 3B in 6, and grade 3C in 7). The grade 3 group had lower pain scores (10.7 ± 6.2 vs. 14.2 ± 1.9, P = .044) and limited active flexion (108.2° ± 42.3° vs. 140.6° ± 26.7°, P = .041) compared with the grade 0-2 group. Subtype comparison showed that the grade 3B group had lower pain scores (7.0 ± 6.7 vs. 15.0 ± 0.0, P = .007) and limited active flexion (80.0° ± 26.2° vs. 140.8° ± 27.5°, P = .010) compared with the grade 3C group. Limited preoperative active external rotation was an individual risk factor for grade 3 GW (odds ratio, 0.93; 95% confidence interval, 0.88-0.99; P = .009). CONCLUSIONS: In the long term (>8 years) after HHR with tendon transfer in patients with CTA, patients with the development of grade 3C GW ultimately achieve pain relief even without revision surgery whereas grade 3B GW is associated with persistent pain and might require revision surgery.

The influence of testing positions and resistance locations on muscle activities during shoulder internal rotation strength measurements in young healthy adults.

BACKGROUND: Although some tests of shoulder internal rotator strength including subscapularis are commonly used in clinical practice, the differences in shoulder muscle activities other than subscapularis muscle among those tests are not well understood. The purpose of this study was to examine the activities of the superficial shoulder muscles in addition to internal rotation strength during two belly-press and three lift-off test positions. METHODS: Thirteen healthy young adult men (age 29.5 ± 5.4 years) were recruited for the present study. They performed isometric shoulder internal rotation against manual resistance during the belly-press test positions with two different resistance locations and the lift-off test with three different arm positions. The surface electromyographic activities of the superficial shoulder muscles, including the deltoid (anterior, middle, posterior), pectoralis major, long head of triceps and latissimus dorsi muscle, were collected and compared between the two belly-press tests, and among the three lift-off test positions (P < 0.05). RESULTS: The belly-press test position with resistance to elbow showed significantly greater activities of the anterior and middle deltoid muscle than the original belly-press test; but showed significantly smaller activities of pectoralis major, triceps and latissimus dorsi muscle than the original belly-press test. Among the three lift-off tests, all muscle activities, except for the pectoralis major, were greater in the lift-off at L4/5 than in the lift-off at buttock and thigh. Lift-off at thigh showed significantly smaller activity of pectoralis major than the lift-off at L4/5 and buttock. CONCLUSIONS: The findings of the present study suggest that clinician should give attention to compensatory motions by excessive shoulder extensor and adductor muscle activities for the original belly press test, by excessive deltoid muscle activities for the modified belly-press, and by excessive shoulder extensor muscle activities for the lift off test in the inferior arm positions.

Glenoid bone resorption after Bankart repair: finite element analysis of postoperative stress distribution of the glenoid.

BACKGROUND: There are various modifications of the Bankart repair, and postoperative changes to the glenoid morphology after the repair are reported. Among the various procedures performed, a decrease in the lateral glenoid diameter might be related to the surgery that involves removal of the articular cartilage and repair of the labrum-anterior inferior glenohumeral ligament complex on the glenoid surface. This is in contrast to cases without significant bony Bankart lesions that are not on the edge of the glenoid. Thus, this study aimed to compare glenoid rim stress after Bankart repair using 2 methods of finite element analysis: a method of removing the anteroinferior cartilage and repairing the glenohumeral ligament complex on the glenoid and a method of preserving the cartilage and repairing the glenohumeral ligament complex on the glenoid edge. METHODS: Five preoperative computed tomography scans of patients with traumatic anterior instability who underwent arthroscopic Bankart repair were used. Two models simulating different surgical procedures were created as follows: in model G, a 5-mm-thick cartilage on the glenoid rim was removed between 2 and 7 o'clock, and the glenohumeral ligament complex was repaired on the medial edge of the glenoid bone where the cartilage was removed. In model E, the cartilage on the glenoid rim was not removed, and the glenohumeral ligament complex was repaired on the glenoid edge. The load stresses on the anteroinferior area of the glenoid after Bankart repair with models G and E were measured using finite element analysis. RESULTS: The stress on the glenoid at 3-4 o'clock was 3.16 MPa in model G and 6.42 MPa in model E (P = .043). The stress at 4-5 o'clock was 1.68 MPa in model G and 4.53 MPa in model E (P = .043). The stress at 5-6 o'clock was 2.26 MPa in model G and 3.93 MPa in model E (P = .043). CONCLUSION: Significantly lower load stresses were observed at the anteroinferior rim of the glenoid in model G than in model E.

Dexamethasone added to levobupivacaine prolongs the duration of interscalene brachial plexus block and decreases rebound pain after arthroscopic rotator cuff repair.

BACKGROUND: It has been reported that the addition of dexamethasone to interscalene brachial plexus block (ISBPB) prolongs the duration of the block effect. However, there have been no studies focusing on the effects of dexamethasone on rebound pain after the block effect has worn off. The aim of this study was to investigate the effect on postoperative pain when dexamethasone was added to ISBPB for arthroscopic rotator cuff repair (ARCR). METHODS: In this multicenter, single-blinded, and randomized controlled study, 54 patients (33 males, 21 females) who received ARCR were randomly assigned to group L (ISBPB with 20 cc of 0.25% levobupivacaine; 21 patients) or group LD (ISBPB with 20 cc of 0.25% levobupivacaine + 3.3 mg dexamethasone; 33 patients). The primary outcome was the visual analog scale (VAS) for pain after the block effect had worn off. Secondary outcomes were the duration of analgesia, the time to the first request for additional analgesic, the number of additional doses of analgesic, and complications. RESULTS: The VAS scores on postoperative days 0 and 1 were significantly lower in group LD than group L (P = .005, .035). This indicated that the rebound pain was relieved in group LD. After postoperative day 1, there was no significant difference in VAS score (P = .43 and .19 for days 2 and 3, respectively). The duration of analgesia was significantly longer in group LD than group L (P < .001). The time to the first request for additional analgesic was significantly longer in group LD than group L (P < .001). The number of additional doses of analgesic was significantly lower in group LD (P < .001). CONCLUSION: In ARCR, the addition of dexamethasone to levobupivacaine not only prolongs the duration of ISBPB but also relieves rebound pain after the block effect wears off.

Humeral bone resorption after anatomic shoulder arthroplasty using an uncemented stem.

BACKGROUND: Bone resorption around the femoral stem after total hip arthroplasty is a well-known phenomenon. However, only a few studies have evaluated bone resorption after shoulder arthroplasty. This study investigated the prevalence of humeral bone resorption after different shoulder arthroplasty procedures. METHODS: The study included 147 shoulders that underwent total shoulder arthroplasty (TSA) or humeral head replacement (HHR) with an uncemented humeral stem from November 2008 to May 2015 and were monitored for more than 1 year. The prevalence of humeral bone resorption and risk factors were investigated. RESULTS: The most advanced grade of bone resorption, grade 0, occurred in 21 shoulders (14.3%). Grade 1 bone resorption occurred in 10 (6.8%), grade 2 in 28 (19.0%), grade 3 in 61 (41.5%), and grade 4 in 27 (18.4%). High occurrence of bone absorption was observed in zones 1, 2, and 7. Grade 4 bone resorption did not occur in zones 3 and 5. HHR, on-growth type stem coating, and occupation ratio were significant independent risk factors for grade ≥3 bone resorption, whereas female sex and HHR were significant independent risk factors for grade 4. CONCLUSION: Bone resorption was observed in 126 shoulders (85.7%), and full-thickness cortical bone resorption occurred in 27 shoulders (18.4%). Bone resorption was frequently observed at the greater tuberosity, lateral diaphysis, and calcar region (zones 1, 2, and 7). Significant risk factors included female sex, HHR with rotator cuff reconstruction, on-growth type stem coating, and high occupation ratio of the implant.

Bone marrow stimulation at the footprint of arthroscopic surface-holding repair advances cuff repair integrity.

BACKGROUND: Bone marrow stimulation (BMS) at the footprint of arthroscopic rotator cuff repair has not been fully evaluated according to the preoperative tear size and surgical technique. In this study, we investigated the effect of BMS on cuff repair integrity after an arthroscopic surface-holding (ASH) repair. MATERIALS AND METHODS: A total of 111 patients (mean age, 64.5 years) with chronic rotator cuff tears who underwent treatment by the ASH method with BMS by drilling of multiple holes at the footprint (67 shoulders) or without BMS (44 shoulders) were studied, and all patients were observed prospectively. Sugaya's classification was used to evaluate cuff integrity by postoperative magnetic resonance imaging, with types IV and V classified as rotator cuff retears. RESULTS: The mean scores for cuff integrity were 2.2 ± 0.2 and 1.7 ± 0.2 in the non-BMS and BMS groups, respectively. The mean scores were similar between the 2 groups for medium tears; however, scores for large-massive tears were significantly lower in the BMS group. The overall retear rate was 23.9% in the non-BMS group and 9.1% in the BMS group, and the distribution of repair types differed significantly. For large-massive tears, the retear rate was much higher in the non-BMS group (28.6%) than in the BMS group (4.5%), although the rates for medium tears were comparable between the 2 groups. CONCLUSIONS: These findings demonstrate that applying BMS to the footprint during ASH repair results in improved cuff repair integrity, particularly in large-massive tears, and suggest the importance of biologic treatment for rotator cuff healing after arthroscopic rotator cuff repair.

Surface-holding repair: an original arthroscopic rotator cuff repair technique.

BACKGROUND: Arthroscopic rotator cuff repair provides satisfactory results; however, there is still a high rate of re-tear. The objective of this study was to present a surface-holding technique that we recently developed for arthroscopic rotator cuff repair in detail and to evaluate the clinical outcome as well as cuff repair integrity with this new method. MATERIALS AND METHODS: A consecutive series of 116 patients with full-thickness rotator cuff tears underwent arthroscopic surface-holding repair and were monitored with the Japanese Orthopaedic Association, Constant-Murley, and University of California-Los Angeles scores to assess the clinical outcome. The mean follow-up period was 17.9 months (range, 12-40 months). Cuff repair integrity was evaluated by magnetic resonance imaging. RESULTS: All 3 rating systems at the time of final follow-up reflected a significant improvement in functional recovery of the shoulder compared with the preoperative scores. The overall rate of rotator cuff retear was 19.0% (22 of 116 shoulders), and the rates were 13.6% (9 of 66 shoulders) for small and medium-sized tears and 26% (13 of 50 shoulders) for large and massive tears. The rate for large and massive tears was much higher in patients older than 70 years (58.3%) compared with those younger than 70 years (36.3%), whereas the retear rates were similar in these 2 groups (22.2% and 17.5%, respectively). CONCLUSIONS: Arthroscopic surface-holding repair technique with medial suture and transosseous fixation improved rotator cuff healing. This method may be useful both for young patients and for elderly patients, who frequently have chronic large and massive tears, including osteoporotic bones.

Suprascapular notch variations: a 3DCT study.

BACKGROUND: Although cadaveric studies have revealed suprascapular notch shape variations, few have investigated the association between suprascapular notch variation and age or gender. The purpose of this study was to investigate suprascapular notch shape variations by use of three-dimensional computed tomography (3DCT) and to determine if there was any association with age or gender. METHODS: Three-dimensional CT images of 762 shoulders of 762 patients were analyzed in this study. Participants comprised 404 men and 358 women, with an average age of 58.2 ± 19.1 years. Suprascapular notch shape variations were classified into six types on the basis of Rengachary's classification. RESULTS: Of the total study population, 11.4% were classified as type I, 23.5% as type II, 30.1% as type III, 14.8% as type IV, 15.9% as type V, and 4.3% as type VI. Average age was 56.5 ± 20.5 years for type I, 57.0 ± 19.5 years for type II, 55.5 ± 20.0 years for type III, 56.4 ± 18.5 years for type IV, 65.5 ± 14.4 years for type V, and 68.0 ± 13.4 years for type VI. Statistically significant age differences were found between types I-IV and V, between types I-IV and VI, and between the non-ossification group (types I-IV) and the ossification group (types V and VI). Male-to-female ratio among each type, and between the non-ossification group and the ossification group, were not statistically significantly different. CONCLUSIONS: Our results suggest that transverse scapular ligament ossification is associated with aging whereas individual variation explains differences among types I, II, III, and IV. Three-dimensional CT provides useful information for arthroscopic resection of the transverse scapular ligament, when the wide variety of suprascapular notch shape variations is considered. LEVEL OF EVIDENCE: Level IV.

Long-term outcomes of hemiarthroplasty using a smaller head combined with rotator cuff reconstruction in patients with cuff-tear arthropathy.

Background: Hemiarthroplasty (HHR) using a smaller head with rotator cuff reconstruction is a treatment option for cuff-tear arthropathy, offering advantages like facilitating rotator cuff-tear closure, increasing the lever arm of deltoid, and restoring function in irreparable cuff tears. This study aimed to evaluate the long-term outcomes of this procedure. Methods: A retrospective analysis was conducted for 91 shoulders undergoing HHR using a smaller head with rotator cuff reconstruction between May 2005 and September 2012. Surgery involved reducing the size of humeral head and performing rotator cuff reconstruction based on the site of the deficient rotator cuff. The study analyzed University of California, Los Angeles shoulder scores, Japanese Orthopaedics Association shoulder scores, range of motion, and postoperative radiographs. Results: Twenty-eight patients, divided into an elderly group (14 women, 2 men, mean age 74.5 ± 3.8 years) and a younger group (6 women, 6 men, mean age 63.5 ± 3.1 years) were followed up for a mean of 133.2 ± 14.1 months. No complications were reported. The clinical scores and range of motion significantly improved postoperatively and remained over 10 years. Radiographs revealed high incidence of glenoid wear (82.1%), bone resorption (43%) and cranial humeral head migration (54%), with no prosthesis loosening. Conclusion: We believe that HHR using a smaller head with rotator cuff reconstruction is a surgical technique that can maintain stable long-term outcomes in both elderly and younger individuals with cuff-tear arthropathy.

Passive shoulder abduction range of motion at 3 months postoperatively is the most important prognostic factor for achieving full recovery of range of motion at 6 months after arthroscopic rotator cuff repair.

Background: After arthroscopic rotator cuff repair (ARCR), it is crucial for clinicians to predict the functional recovery in the early postoperative period for considering rehabilitation strategies. The aim of this study was to identify the prognostic factors in the early postoperative period for achieving full recovery of range of motion (ROM) at 6 months after ARCR. Methods: This study included 184 patients who underwent ARCR. Patients were divided into the full recovery and nonrecovery groups using the Constant ROM score at 6 months postoperatively. The area under the curve for predicting the full recovery group was calculated for all independent variables such as demographic data, ROM, shoulder functional scores at preoperative and 3 months postoperative using receiver operating characteristic curve analysis. Multivariable logistic regression analysis was then performed using candidate variables with an area under the curve of 0.7 or greater to determine prognostic factors for full recovery at 6 months postoperatively. The same analysis as above was also performed by dividing the patients into groups according to their preoperative ROM. Results: Multivariable logistic regression analysis revealed that preoperative active flexion, 3 months postoperative passive abduction, and internal rotation at 90° abduction ROM were significant prognostic factors of achieving full ROM recovery at 6 months postoperatively. Only passive abduction ROM at 3 months postoperatively was significantly extracted in the preoperative ROM limitation group. Conclusion: This study demonstrated that passive abduction ROM at 3 months postoperatively was a significant prognostic factor of achieving full recovery of ROM at 6 months after ARCR.

Academic Engagement of Women as Orthopaedic Surgeons at the Annual Meetings of the Japanese Orthopaedic Association From 2012 to 2022.

BACKGROUND: Higher gender diversity correlates with higher patient satisfaction, higher-quality medical education, increased research productivity, and higher revenues. Although the field of Japanese orthopaedic surgery includes the lowest proportion of women and lags in gender diversity, reports on the current gender diversity status in academic activities are scarce. We investigated changes in women's participation in academic activities at the Japanese Orthopaedic Association (JOA) annual meetings over the past 11 years. METHODS: Data on the percentage of women in the JOA membership during 2012-2022 were analyzed to ascertain the proportion of women as first authors of oral and poster presentations, abstract reviewers, invited lecturers, seminar lecturers, general abstract oral chairpersons, symposium chairpersons, and speakers. Regarding the ratio of women among the JOA members during 2012-2022, we relied on data provided by the JOA. Data related to other categories were collected from the abstract book presented at the JOA Annual Meetings between 2012 and 2022. We analyzed the time trend for women's proportions using the Cochran-Armitage trend test. A p-value < 0.05 was considered statistically significant. RESULTS: During 2012-2022, the percentage of female members (4.9-6.7%), poster first authors (2.7-4.3%), abstract reviewers (0-1.5%), general abstract oral chairpersons (0-2.3%), symposium chairpersons (0-3.6%), and symposium speakers (1.6-6.8%) had increased significantly (p < 0.05). Oral first authors (2.2-4.1%), invited lecturers (0-6.8%), or seminar lecturers (0%-6.7%) showed no trend. Women engaged in academic activities at all annual association meetings did not exceed the women's proportion among the association members. CONCLUSION: Although the proportion of women members of the JOA has gradually increased and more women are involved in its annual meetings, the proportion of female presenters, invited speakers, symposiasts, and chairpersons of oral and poster presentations is generally lower than that of women as JOA members. Members should be asked to raise awareness, including more active education of women as physicians in educational institutions and the creation of positive actions to select women as physicians for more important roles (chairpersons, educational speakers, and symposiasts) in the organization of annual meetings.

Correction in malrotation of the scapula and muscle transfer for the management of severe Sprengel deformity: static and dynamic evaluation using 3-dimensional computed tomography.

BACKGROUND: The clinical results of surgical procedures for severe Sprengel deformity have been uncertain. To obtain improved elevation, we consider that it is necessary to realign the lateral border of the scapula for upward rotation. The purposes of the current study were to evaluate the clinical results and range of motion of the scapula after such realignment. METHODS: Seven cases of Sprengel deformity of Cavendish grade 3 or 4 were treated surgically and then clinically evaluated and examined using 3-dimensional computed tomography (3D CT). (Two boys and 5 girls aged 50.9 ± 15.4 mo, mean ± SD at the time of operation.) The mean follow-up was 53.1 months (range, 12 to 92 mo). After the omovertebral bone and the superomedial side of the scapula were removed, the levator scapulae and rhomboids were reattached to wrap around the scapula at maximum upward rotation to assist in maintaining this position. Cavendish and Rigault grades were used for evaluation of postoperative appearance. The superior displacement and rotation of the scapula were measured on the trunk posterior view using 3D CT. The relationship between improvement in the range of motion and radiologic change were analyzed statistically. RESULTS: The postoperative flexion (97.9 ± 12.9 to 160 ± 11.5 degrees) and abduction (99.3 ± 13.0 to 161.4 ± 15.7 degrees) were significantly improved compared with the mean preoperative values (P < 0.0001). 3D CT revealed that in all patients the malrotation of the scapula was improved postoperatively. The current study shows that successful realignment of the scapula led to these improved clinical results. CONCLUSIONS: Our procedure has advantages not only for recovery of the range of motion but also for reducing the characteristic lump in the web of the neck. However, our procedure has an inherent limitation related to asymmetric shoulder level and width. 3D CT may be useful for preoperative planning and postoperative evaluation. LEVEL OF EVIDENCE: Level IV-case series.

Relationship between hematoma-like tissue on the footprint and structural outcome of arthroscopic rotator cuff repair with a transosseous technique.

Background: We have tried to create hematoma over the footprint site at the end of arthroscopic rotator cuff repair (ARCR) surgery, expecting to apply biochemical effects of the platelet-related factors. The purpose of this study was to investigate the presence of hematoma-like tissue (HLT) on postoperative magnetic resonance imaging, and to evaluate the relationship between the HLT and the structural outcomes of ARCR. Materials and methods: Twenty-five patients were reviewed with a mean age at surgery of 69.8 years (range, 52-85 years). Postoperative magnetic resonance imaging was performed at 1 week, 6-8 weeks, and >6 months postoperatively. Structural outcomes for the repaired cuff and thickness of HLT were evaluated on coronal T2-weighted images. Signal intensity of HLT was evaluated on coronal T2-weighted fat-suppressed images as the ratio compared to supraspinatus tendon intensity (HLT/SSP ratio). Results: Structural outcomes showed Sugaya type 1 in 12 shoulders, type 2 in 4, and type 3 in 9. HLT thickness was significantly thicker at 1 week and 6-8 weeks postoperatively in Sugaya type 1 patients than in type 3 patients (1 week; P = .014, 6-8 weeks; P < .001). HLT/SSP ratio gradually decreased (at 1 week; 1.9 ± 0.7, 6-8 weeks; 1.6 ± 0.6, >6 months; 1.2 ± 0.5), and differed significantly between >6 months and both 1 week and 6-8 weeks (P < .001 each).

Differences in incidence rate and onset timing of undiagnosed finger symptom among shoulder surgeries related to complex regional pain syndrome.

The purpose of this study was to clarify the difference in onset timing and incidence of undiagnosed finger symptom (UDFS) between various shoulder surgical procedures. In this study, UDFS symptoms included the following four symptoms in the fingers;edema, limited range-of-motion, skin color changes, and abnormal sensations. UDFS cases were defined as those presenting with at least one UDFS. In result, the incidence rate of UDFS cases was 7.1% overall (58/816 shoulders), 7.4% (32/432) in arthroscopic rotator cuff repair (ARCR), 9.0% (11/122) in open rotator cuff repair (ORCR), 1.4% (2/145) in arthroscopic subacromial decompression (ASD), 13.2% (5/38) in open reduction and internal fixation (ORIF), 11.1% (3/27) in humeral head replacement, 4.8% (1/21) in anatomical total shoulder arthroplasty, and 12.9% (4/31) in reverse total shoulder arthroplasty cases. The Rate was significantly higher with ARCR compared to ASD (p<.01). About onset timing in weeks postoperatively, the ORIF group had a statistically earlier symptom onset than the Rotator cuff repair (ARCR + ORCR) group (2.4 weeks vs. 6.0 weeks, p<.01). When classifying the onset timing into before and after the removal of the abduction pillow, the ORIF group showed a statistically higher rate of onset before brace removal than the Rotator cuff repair groups (p<.01). Differences in UDFS among shoulder surgeries were demonstrated in this study. J. Med. Invest. 70 : 415-422, August, 2023.

Correlation of suprascapular notch morphology with suprascapular nerve palsy: a 3D-computed tomography study.

Background: The morphology of the suprascapular (SS) notch is a very important factor in treatment of suprascapular nerve (SSN) palsy. Several studies have reported SS notch morphology in cadavers or using a three-dimensional computed tomography (3D-CT); however, none has reported the distribution of SS notch morphology according to the age group. In addition, the correlation between SS notch morphology and SSN palsy remains unclear. The purposes of this study were to investigate the morphological distribution of the SS notch by age group in a large population and to assess the relationship between SS notch morphology and SSN palsy. Methods: We studied the 3D-CT images of 1063 shoulders in 1009 patients (mean age, 60.8 years; age range, 14-96 years). There were 53 shoulders with SSN palsy and 1010 shoulders without SSN palsy. Morphology of the SS notch was classified by Rengachary's classification (types I-VI). Shoulders with types I-IV were classified into the nonossified superior transverse scapular ligament (STSL) group (group N) and those with types V and VI into the ossified STSL group (group O). Results: The Rengachary's classifications of the 1063 shoulders were as follows: type I: n = 113, 10.6%; type II: n = 313, 29.4%; type III: n = 383, 36.0%; type IV: n = 109, 10.3%; type V: n = 107, 10.0%; and type VI: n = 38, 3.6%. Mean age was significantly older in the ossified STSL group, and the age was <40 years for only two shoulders in this group. The Rengachary's classifications of the SSN palsy cases were as follows: type I: 7.5%, II: 24.5%, III: 34.0%, IV: 15.1%, V: 13.2%, and VI: 5.7%. There was no statistical difference in age and sex, Rengachary type, or ossification between SSN palsy and non-SSN palsy cases. Conclusions: Ossification of the STSL was significantly more common in older patients, which suggests age-related change. In addition, no relation was identified between narrow notch or ossification of the STSL with the onset of SSN palsy.

Recovery of sensory disturbance after arthroscopic decompression of the suprascapular nerve.

BACKGROUND: The existence of sensory branches of the suprascapular nerve (SSN) has recently been reported, and sensory disturbance at the lateral and posterior aspect of the shoulder has been focused on as a symptom of SSN palsy. We have performed arthroscopic release of SSN at the suprascapular notch in patients with sensory disturbance since 2006. The purposes of this study were to introduce the arthroscopic surgical technique and investigate postoperative recovery of sensory disturbance. MATERIALS AND METHODS: The study included 11 men and 14 women (25 shoulders), with an average age of 63.9 years (range, 41-77 years). Arthroscopic decompression of the SSN was performed using a suprascapular nerve (SN) portal as a landmark for approaching the suprascapular notch. Sensory disturbance of the shoulder was evaluated preoperatively and postoperatively. The average follow-up was 18.5 months (range, 12-30 months). RESULTS: The arthroscopic procedures were performed safely. The preoperative sensory disturbance fully recovered postoperatively in all shoulders. CONCLUSION: Arthroscopic release of the SSN is a useful procedure for SSN entrapment at the suprascapular notch. The sensory disturbance at the lateral and posterior aspect of the shoulder can be used as one of the criteria of diagnosing SSN palsy, especially in shoulders with massive rotator cuff tear, in which diagnosing and assessing the treatment results of associated SSN palsy is usually difficult.