Does the critical shoulder angle decrease after acromioplasty? A systematic review and meta-analysis

Background Rotator cuff tears are one of the most common shoulder injuries in the older population. This study aimed to determine whether acromioplasty reliably decreases the critical shoulder angle (CSA) and describe any associated complications. Methods A systematic literature review was performed according to PRISMA guidelines using PubMed, EMBASE, Web of Science, and Cochrane Library Database. Two reviewers independently screened the titles and abstracts using prespecified criteria. Studies where the acromioplasty was performed as a surgical procedure were included. Patient characteristics and degree of CSA reduction were collected from each individual study. All statistical analyses were performed using Review Manager (RevMan) 5.4.1 software. A random-effects model was used for meta-analysis. Results A total of 9 studies involving 1236 patients were included in the meta-analysis. The age of patients ranged from 23 to 82 years. The follow-up period ranged from 12 to 30 months. Of the 9 studies, 8 (88.9%) were retrospective, 1 (11.1%) was prospective, 5 were comparative, and 4 were case series. The mean CSA was significantly reduced from 36.1° ± 4.6° to 33.7° ± 4.2 (p < 0.05). The meta-analysis showed an overall best estimate of the mean difference in pre- and postoperative CSA equal to 2.63° (95% confidence interval: 2.15, 3.11] (p < 0.00001). Conclusions Acromioplasty can significantly reduce CSA, notably in cases of high preoperative CSA. In addition, the effect of lateral acromioplasty on the CSA was more significant compared to anterolateral acromioplasty. Acromioplasty was not associated with complications during the short-term follow-up.

Immediate Effect of Chin Tuck Exercises on Craniovertebral Angle and Shoulder Angle Among Collegiates with Forward Head Posture

Forward head posture (FHP) is the forward movement of the head that is caused by improper postural awareness and often results in muscular imbalance that causes pain. The forward head posture is found to be influenced by Craniovertebral Angle (CV) and shoulder angle (SA) that in turn causes rounded shoulder. These biomechanical changes prove to be a hindrance in maintaining neutral head posture and affects the structural integrity. A sample size of 43 were taken according to the selection criteria and the FHP was assessed through plumb line. Double tape was used as markers at tragus of the ear, C7 vertebrae and acromion process. Photos were taken and analyzed using AUTOCAD 2017 software and the results were obtained. A positive association found between the pre and post test results for CV angle with P=0.0001(P<0.05) and no significant association between the pre and posttest for SA with P=0.2 (P>0.05). The craniovertebral angle can be altered with the chin tuck exercises but has no effect on the shoulder angle, hence having no influence over the rounded shoulders but has some effect over the forward head posture.

COMPARISON OF SCAPULAR MORPHOLOGY IN DEGENERATIVE AND TRAUMATIC ROTATOR CUFF TEARS

Background: Degenerative cuff tears have impingement pathophysiology due to altered scapular morphology as measured by increased critical shoulder angle (CSA), decreased lateral acromial angle (LAA) and increased acromion index (AI). But scapular morphology in traumatic tears has neither been studied nor compared with degenerative tears. Aim: To compare scapular morphology with CSA, LAA, AI between traumatic and degenerative tears and determine their reliability. Methods: This observational study includes 100 patients (50 with traumatic and degenerative tears). We analyzed MRI and standardized AP shoulder radiograph of these patients. Parameters, such as CSA, LAA, AI, were measured on AP radiographs by two separate observers in a blinded manner. The 1st observer repeated measurements after four weeks. We compared age, gender, degree of cuff tear, and CSA values, LAA, and AI between the two groups. Results: On comparison using chi-square test, degenerative group had significantly higher age, higher CSA (mean 37.55, SD 0.88 versus traumatic group mean 36.6, SD 0.95, [Formula: see text]-[Formula: see text], highly significant), higher AI (mean 0.73, SD 0.02 versus traumatic mean 0.69, SD 0.04 [Formula: see text]-[Formula: see text], highly significant), and lower LAA (77.14, SD 2.03 versus traumatic mean 78.36, SD 2.73, [Formula: see text]-value 0.013, significant). Interobserver and intraobserver reliability of parameters using the intraclass correlation coefficient (ICC) revealed excellent (CSA, LAA) and good (AI) agreement. ROC curve analysis calculated sensitivity (0.7) and specificity (0.66) to diagnose degenerative tear for CSA above 37.05[Formula: see text]. Conclusion: Scapular morphology in traumatic tears differs from degenerative. CSA, LAA, AI can be reliably measured on standardized shoulder AP radiographs.

Associations between radiographic parameters in the reverse shoulder arthroplasty and patient outcomes

Background Various radiological parameters have been measured in the Reverse Shoulder Arthroplasty (RSA) and correlated to patient outcomes, to determine best baseplate position. Results remain unclear with respect to certain parameters such as inferior baseplate tilt. We have investigated our series of patients to clarify the relationship between radiological parameters and patient outcomes. Methods We conducted a UK based bi-centre retrospective review of 156 prostheses. Critical shoulder angle (CSA), RSA angle (RSAA), Overhang and Deltoid Lever Arm (DLA) were measured on preoperative and postoperative radiographs. Range of motion and Oxford Shoulder Score (OSS) (range 1–8 years) were obtained. We assessed for scapular notching at minimum 1 year follow up (n = 138). Results Decreased postoperative CSA and increased DLA were associated with higher OSSs (P = 0.001 and 0.019). Increased overhang and DLA were associated with increased flexion (P = 0.033 and 0.024 respectively). Multivariate analysis showed that CSA and DLA affected notching rate (P = 0.002 and 0.007). Conclusions Baseplate tilt in relation to the acromion (CSA) and DLA are the most predictive parameters for notching and OSS. We recommend considering a maximum CSA of 26 degrees to decrease notching rate and improve OSS. We recommend considering an Overhang of at least 6 mm to improve FF.

Controversy on the Association of the Critical Shoulder Angle and the Development of Degenerative Rotator Cuff Tears: Is There a True Association? A Meta-analytical Approach

Background: The role of the critical shoulder angle (CSA) as a risk factor for rotator cuff tear (RCT) remains controversial. Studies on the association between the CSA and RCT show considerable differences in design, and this could be responsible for the variation in study results. Purpose: To (1) describe the reliability of CSA measurement and (2) evaluate the results of the studies reporting the association between the CSA and RCT using meta-analytical techniques to explore potential sources of variation of study results. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: MEDLINE, EMBASE, and CINAHL electronic databases were searched through June 30, 2019. Case-control and cross-sectional studies reporting the association of the CSA and RCT were selected. The weighted mean difference in the CSA was estimated using a random-effects model. Prediction interval was computed to better express uncertainties in the effect estimate. Metaregression and subgroup analyses were performed to explore potential sources of heterogeneity. Results: A total of 14 studies, including 1154 cases and 1271 controls, were identified. Of these studies, 79% (11/14) assessed the reliability of the CSA measurement, demonstrating an excellent intraobserver (range, 0.91-0.99) and interobserver (range, 0.87-0.99) reliability. Compared with controls, cases with RCT showed larger measurements of the CSA (3.3° [95% CI, 2.3°- 4.4°]). However, there was a high heterogeneity ( I2 = 93%), and the 95% prediction interval (-0.4° to 7.1°) included no difference in the CSA. Results of the metaregression analysis showed a significant association of several methodological aspects with the heterogeneity. The difference in the CSA tended to be larger when only full-thickness tears were included, when no specific defined criterion for assessing radiographic viewing perspective was used, in studies with smaller sample sizes, and in studies at higher risk of bias. Conclusion: While the CSA can be reliably measured, the difference in the CSA between cases and controls varied from very large to modest or almost no difference. Several determinants of heterogeneity were determined. Owing to this heterogeneity, it is difficult to gain an insight into the strength and exact nature of the association between the CSA and RCT with the current evidence.