Relationship between shoulder and elbow range of motion and ultrasonographic structural abnormalities in the elbow of Taiwanese high school baseball players.

BACKGROUND: Ultrasonographic structural abnormalities are regarded as one of the risk factors of elbow injuries. Elbow injuries are commonly associated with decreased shoulder/elbow range of motion (ROM). The purpose of this study is to determine the relationship between shoulder/elbow ROM and elbow ultrasonographic structural abnormalities in Taiwan high school baseball players. METHODS: A total of 533 Taiwan high school baseball players were enrolled. Physical examinations including measurements on shoulder/elbow ROM and elbow sonographic examinations were performed and recorded by professional physicians. The analyses were conducted in three subgroups according to their defensive position because the training programs were different. All players pooled, pitchers-only, and fielders-only, due to several demographic differences among these subgroups. In all the subgroups, univariate analyses were conducted separately for participants with and those without elbow ultrasonographic structural abnormalities, and then multivariate analyses were conducted to identify factors significantly related. The odds ratios (ORs) were used to estimate the risk of elbow ultrasonographic structural abnormalities. RESULTS: Demographic data showed that pitchers had taller body height (P < 0.001) and greater elbow flexion/extension ROM (P < 0.001). When all players were pooled, significant risk factors included started playing baseball at an younger age (OR = 1.202; 95% CI = 1.064-1.357; P = 0.003), longer experience of official baseball (OR = 1.154; 95% CI = 1.038-1.283; P = 0.008), lower total shoulder rotation angle (OR = 1.007; 95% CI = 1.000-1.014; P = 0.050), and less total elbow arm angle (OR = 1.052; 95% CI = 1.017-1.088; P = 0.003) For pitchers, significant risk factors included longer experience of official baseball (OR = 1.342; 95% CI = 1.098-1.640; P = 0.004), lower total shoulder rotation angle (OR = 1.016; 95% CI = 1.004-1.027; P = 0.006), and lower total elbow arm angle (OR = 1.075; 95% CI = 1.024-1.129; P = 0.004) (Table 5). There were no significant risk factors for elbow structural abnormalities in fielders. CONCLUSION: For Taiwan high school pitchers, longer official baseball experience, decreased shoulder total rotational angle, and decreased elbow total flexion/extension angle, were related to ultrasonographic structural abnormalities in elbows.

Global Compressive Loading from an Ultra-Thin PEEK Button Augment Enhances Fibrocartilage Regeneration of Rotator Cuff Enthesis.

A PEEK button is developed to improve the tendon-to-bone compression area. In total, 18 goats were divided into 12-week, 4-week, and 0-week groups. All underwent bilateral detachment of the infraspinatus tendon. In the 12-week group, 6 were fixed with a 0.8-1 mm-thick PEEK augment (A-12, Augmented), and 6 were fixed with the double-row technique (DR-12). Overall, 6 infraspinatus were fixed with PEEK augment (A-4) and without PEEK augment (DR-4) in the 4-week group. The same condition was performed in the 0-week groups (A-0 and DR-0). Mechanical testing, immunohistochemistry assessment, cell responses, tissue alternation, surgical impact, remodeling, and the expression of type I, II, and III collagen of the native tendon-to-bone insertion and new footprint areas were evaluated. The average maximum load in the A-12 group (393.75 (84.40) N) was significantly larger than in the TOE-12 group (229.17 (43.94) N) (p < 0.001). Cell responses and tissue alternations in the 4-week group were slight. The new footprint area of the A-4 group had better fibrocartilage maturation and more type III collagen expression than in DR-4 group. This result proved the novel device is safe and provides superior load-displacement to the double-row technique. There is a trend toward better fibrocartilage maturation and more collagen III secretions in the PEEK augmentation group.

Muscle Edema of Retraction and Pseudo-Fatty Infiltration After Traumatic Rotator Cuff Tears: An Experimental Model in Sheep.

Background: Traumatic rotator cuff tears can result in retraction of the tendon and may be associated with muscle edema, which may be confused with fatty infiltration as seen on magnetic resonance imaging (MRI). Purpose: To describe the characteristics of a type of edema associated with acute retraction of the rotator cuff tendon (termed "edema of retraction") and to highlight the risk of mistaking it with pseudo-fatty infiltration of the rotator cuff muscle. Study Design: Descriptive laboratory study. Methods: A total of 12 alpine sheep were used for analysis. On the right shoulder, osteotomy of the greater tuberosity was performed to release the infraspinatus tendon; the contralateral limb acted as the control. MRI was performed immediately after surgery (time zero) and at 2 and 4 weeks postoperatively. T1-weighted, T2-weighted, and Dixon pure-fat sequences were reviewed for hyperintense signals. Results: Edema of retraction resulted in hyperintense signals around or within the retracted rotator cuff muscle on both T1- and T2-weighted imaging, but there was an absence of hyperintense signals on Dixon pure-fat imaging. This represented pseudo-fatty infiltration. Edema of retraction created a characteristic "ground glass" appearance of the muscle on T1-weighted sequences and was often found in either the perimuscular or intramuscular location of the rotator cuff muscle. Compared to time zero values, a decrease in the percentage of fatty infiltration was observed at 4 weeks postoperatively (16.5% ± 4.0% vs 13.8% ± 2.9%, respectively; P < .005). Conclusion: The location of edema of retraction was often peri- or intramuscular. Edema of retraction presented as a characteristic "ground glass" appearance of the muscle on T1-weighted sequences and led to a decrease in the fat percentage because of a dilution effect. Clinical Relevance: Physicians should be aware that this edema can result in a form of pseudo-fatty infiltration, as it is associated with hyperintense signals on both T1- and T2-weighted sequences, and it can be mistaken for fatty infiltration.

Comparison of suture-bridge and independent double-row techniques for medium to massive posterosuperior cuff tears: a two-year retrospective study.

BACKGROUND: Transosseous-equivalent suture-bridge (TOE-SB) and independent double-row (IDR) repair techniques were developed to treat rotator cuff tears. The study was designed to prove that both TOE-SB and IDR techniques provided comparable clinical results and retear rate for medium to massive posterosuperior rotator cuff tears, while the surgical time and number of suture anchor used were less in the IDR group. STUDY DESIGN: Level of evidence: level III, Retrospective comparative study. METHODS: Patients with medium to massive posterosuperior rotator cuff tears receiving arthroscopic TOE-SB and IDR between November 2016 to October 2019 were retrospectively enrolled. All patients were confirmed to have grade ≤ 2 fatty infiltration in the muscles of the torn tendons. Revision, concomitant subscapularis tear, acromiohumeral distance < 7 mm, glenohumeral osteoarthritis, partial repair, incomplete repair, partial thickness, or irreparable posterosuperior cuff tear were excluded. Surgical time, number of suture anchor used for the surgery, pre-operative, and post-operative clinical scores such as Constant-Murley score, subjective shoulder value (SSV), and visual analog scale (VAS) were compared. The retear rates between groups were evaluated by ultrasound. RESULTS: Thirty-five IDR and thirty-five TOE-SB repairs were enrolled. The IDR technique required much fewer anchors than TOE-SB did to complete the cuff repair. The mean operation time in IDR and TOE-SB group were 86(18.23), and 114(18.7) (min), respectively (P <  0.01). The mean number of anchors used to complete the cuff repair was 2(0.17) in IDR and 3(0.61) in TOE-SB (P <  0.01). The Constant-Murley score improved from 34.9 ± 6.6 to 80.6 ± 9.4 in the IDR group, and 37.4 ± 6 to 81.9 ± 4.6 in the TOE-SB group (both P <  0.001). SSV improved from 24.6 ± 9.6 to 79.3 ± 10.6 in the IDR, and 27.9 ± 9 to 82.9 ± 6.9 in the TOE-SB group (both P <  0.001). VAS improved from 7.9 ± 0.6 to 1.5 ± 0.7 in the IDR, and 8 ± 0.5 to 1.3 ± 0.6 in the TOE-SB group (both P <  0.001) at final follow-up. No significant difference was found between the retear rates (14.3% in the IDR vs. 17.1% in the TOE-SB, respectively) in the 2-year follow-up. CONCLUSIONS: Both IDR and TOE-SB group provided comparable clinical results and retear rates for medium to massive posterosuperior rotator cuff tears. The surgical time and number of anchors used were less in the IDR group than in the TOE-SB group.

Comparison of hook plate alone, hook plate augmented with suture anchor, and arthroscopically-assisted tightrope fixation in the treatment of patients with acute type v acromioclavicular joint dislocations.

INTRODUCTION: The best treatment for Rockwood type V acromioclavicular (AC) joint dislocation is unknown. HYPOTHESIS: Hook plate augmented with suture anchor (HA) may have different clinical and radiological results than hook plate alone (H), and arthroscopically assisted TightRope (TR) techniques in treating acute type V AC joint dislocations. MATERIAL AND METHODS: This retrospective study included 71 patients with acute type V AC joint dislocations between December 2010 and August 2018. Patients were categorized into three groups: H group (n=22), HA group (n=23) and TR group (n=26). We measured the coracoclavicular distance (CCD) differences and CCD ratio compared to uninjured side pre-operatively, immediately post-operatively, at 3-month and 2-year after operation. Clinical outcomes were assessed as well at the same time points. Loss of correction was determined by the CCD difference and ratio between surgical and uninjured sides. RESULTS: The mean age and follow-up period were 41.8±24.7 years and 30.2±4.3 months, respectively. No significant differences were found in the demographic data between the three groups. The HA group presented a trend of less overcorrection but without significance compared with the H group at immediately post-operation, 3-month, and 2-year follow-up. (CCD difference: -2.4mm vs. -3.7mm, -1.6mm vs. -1.8, and 0.2mm vs -1.9mm, CCD ratio: 67.7% vs. 40.9%, 79.3% vs. 70.1%, and 100.6% vs. 86.5%, respectively). The HA group also had significantly less loss of correction compared with the TR group at 3-month and 2-year after the operation (CCD difference: -1.6mm vs. 1.6mm, 0.2mm vs. 2.4mm; CCD ratio: 79.3% vs. 122.2%, 100.6% vs. 136.1%, all p<0.05). All three methods achieved significant improvement in function and pain without inter-group differences. No coracoid-related or tunnel complications occurred. DISCUSSION: The hook plate alone, and hook plate with suture anchor augmentation techniques provided less residual vertical instability compared to TightRope fixation at 2-year follow-up. The patient-reported functional outcomes were promising and comparable among the three groups. LEVEL OF EVIDENCE: III, Retrospective comparative therapeutic trial.

Single Assessment Numeric Evaluation for instability as an alternative to the Rowe score.

BACKGROUND: Several functional outcome scores have been proposed for the evaluation of shoulder instability. Most are multiple-item questionnaires, which can be time-consuming and difficult for patients to understand, as well as leading to lack of compliance. The Single Assessment Numeric Evaluation (SANE) score is a single question that has recently gained widespread acceptance based on its simplicity and correlation with more complex scoring systems. The purpose of this study was to assess the correlation of a new modified version of the SANE score, the SANE-instability score, with the Rowe score after treatment for shoulder instability. MATERIALS AND METHODS: We prospectively evaluated a consecutive series of 253 patients (268 shoulders) treated surgically or nonoperatively for shoulder instability between November 2017 and November 2019, for whom the Rowe and SANE-instability scores were collected before treatment and/or after treatment. The SANE-instability score was assessed with the following question: "What is the overall percent value of your shoulder if a completely stable shoulder represents 100%?" Correlations were tested using the Pearson coefficient (r) and interpreted as very high (r = 0.90-1.00), high (r = 0.70-0.89), moderate (r = 0.50-0.69), low (r = 0.30-0.49), or negligible (r = 0.00-0.29). Subgroup analyses were also performed to observe correlation variations according to follow-up length (before treatment and at 6, 12, 26, 52, and 104 weeks after treatment), patient age (<20, 20-29, 30-39, or ≥40 years), and type of treatment (nonoperative or surgical). RESULTS: The overall correlation between the SANE-instability and Rowe scores was high (r = 0.85, P < .001). Subgroup analyses revealed that the correlation between the 2 scores was high before treatment (r = 0.74); moderate at 6 and 12 weeks after treatment (r = 0.66 and r = 0.57, respectively); and then high at 26, 52, and 104 weeks after treatment (r = 0.75, r = 0.75, and r = 0.78, respectively) (P < .001). The correlation was high across all types of treatment (r = 0.76-0.85), high for patients aged ≥ 20 years (r = 0.80-0.86), and very high for patients aged < 20 years (r = 0.93) (P < .001). CONCLUSION: This study demonstrated a significant correlation between the SANE-instability and Rowe scores before and after treatment, as well as across all patient age groups and treatments. Owing to its high simplicity, the SANE-instability score could be used as an alternative to the Rowe score for patient follow-up at various time points.

Diagnostic Accuracy of Clinical Tests for Subscapularis Tears: A Systematic Review and Meta-analysis.

BACKGROUND: Previous systematic reviews and meta-analyses on the diagnostic accuracy of shoulder clinical tests do not reach conclusions regarding subscapularis tears. PURPOSE: To compare the diagnostic accuracy of commonly used clinical tests for subscapularis tears. STUDY DESIGN: Systematic review; Level of evidence, 3. METHODS: An electronic literature search was conducted using Medline, Embase, and the Cochrane Library/Central. Eligibility criteria were original clinical studies reporting the diagnostic accuracy of clinical tests to diagnose the presence of rotator cuff tears involving the subscapularis. RESULTS: The electronic literature search returned 2212 records, of which 13 articles were eligible. Among 8 tests included in the systematic review, the lift-off test was most frequently reported (12 studies). Four tests were eligible for meta-analysis: bear-hug test, belly-press test, internal rotation lag sign (IRLS), and lift-off test. The highest pooled sensitivity was 0.55 (95% CI, 0.28-0.79) for the bear-hug test, while the lowest pooled sensitivity was 0.32 (95% CI, 0.13-0.61), for the IRLS. In all tests, pooled specificity was >0.90. CONCLUSION: Among the 4 clinical tests eligible for meta-analysis (bear-hug test, belly-press test, IRLS, and lift-off test), all had pooled specificity >0.90 but pooled sensitivity <0.60. No single clinical test is sufficiently reliable to diagnose subscapularis tears. REGISTRATION: PROSPERO (CRD42019137019).

'Frozen shoulder' is ill-defined. How can it be described better?

Frozen shoulder, a common and debilitating shoulder complaint, has been the subject of uncertainty within the scientific literature and clinical practice.We performed an electronic PubMed search on all (1559) articles mentioning 'frozen shoulder' or 'adhesive capsulitis' to understand and qualify the range of naming, classification and natural history of the disease. We identified and reviewed six key thought leadership papers published in the past 10 years and all (24) systematic reviews published on frozen shoulder or adhesive capsulitis in the past five years.This revealed that, while key thought leaders such as the ISAKOS Upper Extremity Council are unequivocal that 'adhesive capsulitis' is an inappropriate term, the long-term and short-term trends showed the literature (63% of systematic reviews assessed) preferred 'adhesive capsulitis'.The literature was divided as to whether or not to classify the complaint as primary only (9 of 24) or primary and secondary (9 of 24); six did not touch on classification.Furthermore, despite a systematic review in 2016 showing no evidence to support a three-phase self-limiting progression of frozen shoulder, 11 of 12 (92%) systematic reviews that mentioned phasing described a three-phase progression. Eight (33%) described it as 'self-limiting', three (13%) described it as self-limiting in 'nearly all' or 'most' cases, and six (25%) stated that it was not self-limiting; seven (29%) did not touch on disease resolution.We call for a data and patient-oriented approach to the classification and description of the natural history of the disease, and recommend authors and clinicians (1) use the term 'frozen shoulder' over 'adhesive capsulitis', (2) use an updated definition of the disease which recognizes the often severe pain suffered, and (3) avoid the confusing and potentially harmful repetition of the natural history of the disease as a three-phase, self-limiting condition. Cite this article: EFORT Open Rev 2020;5:273-279.DOI: 10.1302/2058-5241.5.190032.

Do short stems influence the cervico-diaphyseal angle and the medullary filling after reverse shoulder arthroplasties?

BACKGROUND: Shorter humeral stems were developed to improve bone preservation, vascularity and osteointegration in reverse total shoulder arthroplasty (RSA). While some studies examined the relationship between canal filling and radiographic changes, none evaluated the association between stem alignment and canal fill ratio (CFR). HYPOTHESIS: The hypothesis was that stem misalignment after RSA would be associated with lower CFR. PATIENTS AND METHODS: The authors retrospectively reviewed immediate postoperative radiographs of 157 patients, comprising 56 men (36%), who underwent RSA with a short uncemented stem with neck shaft angle (NSA) default of 145°. The parameters included postoperative NSA and metaphyseal CFR, both measured with excellent inter-observer agreement. Uni- and multivariable linear regressions were performed to determine associations between postoperative NSA and 5 variables (CFR, gender, age, BMI, and surgical approach). RESULTS: Postoperative NSA was 149°±8°, exceeding 5° of varus in 15 shoulders (9%) and 5° of valgus in 60 shoulders (38%), and CFR was 58%±8%. CFR was lower in shoulders with varus stem alignment (54%±6%) than shoulders with neutral stem alignment (59%±8%, p=0.033). Multivariable regression revealed that postoperative NSA increased with age (beta: 0.20; p=0.008), was higher for shoulders operated with the subscapularis- and deltoid-sparing approach (beta: 3.82; p=0.040) but lower for men (beta: -4.14; p=0.002). CONCLUSIONS: Stem misalignment exceeded 5° in 47% of the shoulders. Women, older age, and subscapularis- and deltoid-sparing approach are associated with greater risks of valgus stem positioning, while lower CFR seems to be associated with greater risks of varus stem positioning. LEVEL OF EVIDENCE: IV; case series.

Effect of humeral stem and glenosphere designs on range of motion and muscle length in reverse shoulder arthroplasty.

PURPOSE: To determine how different combinations of humeral stem and glenosphere designs for reverse shoulder arthroplasty (RSA) influence range of motion (ROM) and muscle elongation. METHODS: A computed tomography scan of a non-pathologic shoulder was used to simulate all shoulder motions, and thereby compare the ROM and rotator cuff muscle lengths of the native shoulder versus 30 combinations of humeral components (1 inlay straight stem with 155° inclination and five onlay curved stems with 135°, 145° or 155° inclinations, using concentric, medialized or lateralized trays) and glenospheres (standard, large, lateralized, inferior eccentric and bony increased-offset (BIO-RSA)). RESULTS: Only five of the 30 combinations restored ≥ 50% of the native ROM in all directions: the 145° onlay stem (concentric tray) combined with lateralized or inferior eccentric glenospheres and the 145° stem (lateralized tray) combined with either a large, lateralized or inferior eccentric glenosphere. Lengthening of the supraspinatus and infraspinatus, observed for all configurations, was greatest using onlay stems (7-30%) and BIO-RSA glenospheres (13-31%). Subscapularis lengthening was observed for onlay stems combined with BIO-RSA glenospheres (5-9%), while excessive subscapularis shortening was observed for the inlay stem combined with all glenospheres except the BIO-RSA design (> 15%). CONCLUSIONS: The authors suggest implanting 145° onlay stems, with concentric or lateralized trays, together with lateralized or inferior eccentric glenospheres.