Critical shoulder angle and failure of conservative treatment in patients with atraumatic full thickness rotator cuff tears

Abstract

Background Atraumatic full thickness rotator cuff tears (AFTRCT) are common lesions whose incidence increases with age. Physical therapy is an effective conservative treatment in these patients with a reported success rate near 85% within 12 weeks of treatment. The critical shoulder angle (CSA) is a radiographic metric that relates the glenoid inclination with the lateral extension of the acromion in the coronal plane. A larger CSA has been associated with higher incidence of AFTRCT and a higher re-tear rate after surgical treatment. However, no study has yet described an association between a larger CSA and failure of conservatory treatment in ARCT. The main objective of this study is to determine whether there is an association between CSA and failure of physical therapy in patients with AFTRCT. Methods We reviewed the imaging and clinical records of 48 patients (53 shoulders), 60% female, with a mean age of 63.2 years (95% CI ± 10.4 years); treated for AFTRCT who also underwent a true anteroposterior radiograph of the shoulder within a year of diagnosis of the tear. We recorded demographic (age, sex, type of work), clinical (comorbidities), and imaging data (CSA, size and location of the tear). We divided the patients into two groups according to success or failure of conservative treatment (indication for surgery), so 21 shoulders (39.6%) required surgery and were classified as failure of conservative treatment. Univariate and multivariate analysis was performed to detect predictors of failure of conservative treatment. Results The median CSA was 35.5º with no differences between those with failure (median 35.5º, range 29º to 48.2º) and success of conservative treatment (median 35.45º, range 30.2º to 40.3º), p = 0.978. The multivariate analysis showed a younger age in patients with failure of conservative treatment (56.14 ± 9.2 vs 67.8 ± 8.4, p < 0.001) and that male gender was also associated with failure of conservative treatment (57% of men required surgery vs 28% of women, p = 0.035). Conclusions It is still unclear if CSA does predict failure of conservative treatment. A lower age and male gender both could predicted failure of conservative treatment in AFTRCT. Further research is needed to better address this subject.

The Critical Shoulder Angle: A Significant Radiological Measure in Rotator Cuff vs. Glenohumeral Osteoarthritis in Chilean Patients—A Descriptive Cross-Sectional Study

“…An anteroposterior X-ray of the glenohumeral complex is crucial not only because it is cost-effective and aids doctors in assessing bone structures [ 40 ] but also because it helps to identify potential soft tissue injuries [ 41 ]. International reports suggest that patients with a high CSA and pain may potentially present unresolved soft tissue injuries, necessitating further studies to confirm this association [ 42 ]. Because the CSA is the main force acting on the glenohumeral joint and the rotator cuff, it might be important to consider it in both RCI and GHOA [ 8 ].…”

Changes in the Lateral Acromion Angle in Rotator Cuff Tear Patients with Acromioplasty

“…20 While AI aids in distinguishing between healthy shoulders and those afflicted with subacromial pathology, it might not provide the same discriminatory capacity between impingement and cuff tears. [21][22][23] In large or massive RCTs, factors such as trauma and degeneration in addition to acromion morphology may play an important role. However, in small or moderate RCTs, the morphology of the acromion may play an important role.…”

“…In addition, the concept of the “Acromial Index” (AI), introduced by Nyffeler et al ., which signifies the lateral extension of the acromion above the humeral head, has emerged as a prognostic marker for RCTs 20 . While AI aids in distinguishing between healthy shoulders and those afflicted with subacromial pathology, it might not provide the same discriminatory capacity between impingement and cuff tears 21–23 . In large or massive RCTs, factors such as trauma and degeneration in addition to acromion morphology may play an important role.…”