THE LINK OF ACROMION MORPHOLOGY TO ROTATOR CUFF TEAR IN ADDIS ABABA: A MATCHED, CASE-CONTROL STUDY IN ADDIS ABABA.

Abstract

Abstract Background: Rotator cuff tear (RCT) is a common cause of shoulder pain. Age, sex, side of the shoulder, trauma history, and acromion morphology are among the risk factors of RCT. However, there are controversies in the literature regarding the relationship between acromion morphology and RCT. To my knowledge, there is no study done in Ethiopia that explored the association between RCT and acromion morphology. The link between RCT and other possible risk factors are not evaluated either. Understanding this relationship will help both radiologists and orthopaedists in their choice of appropriate diagnostic and intervention approaches, respectively. Objectives: To determine the link of RCT to acromion morphology and other possible risk factors using magnetic resonance imaging (MRI). Methods: This is a retrospective, hospital-based, matched case-control study of patients who underwent shoulder MRI, at St. Paul’s Millennium Medical College (SPHMMC) from October 2018 to September 2020. A total of 80 individuals, 40 cases (diagnosed with RCT) and 40 controls (not diagnosed with RCT) were recruited. Shoulder MRI image reports of cases and controls were reviewed from the Radiological Information system, based on which categorization into cases and controls, and characterization of acromion morphology were done. The relation of RCT to acromion morphology and other risk factors were examined using the McNemar test stastics and Conditonsl logistic regression procedure. Results :The mean age in years for cases and controls is 42 and 43 respectively. Of those with rotator cuff tear the majority (60%) are between 40 and 60 years of age. Among cases,Type I,Type II,Type III,& type IV acromion account for 32.5%,55%,15%,and 2.5% respectively. Acromion Spurs,Os Acromiale,and acromio-humeral distance ≤ 7 mm are observed among cases than controls at McNemar test p value of <0.001. Supraspinatus tear is the most common type of tea accounting for 81%. The age and sex matched univariate analysis didn’t show any statistically significant association between the potential predictor variables and rotator cuff tear Conclusion and recommendation: Side of the shoulder,type of acromion,acromial spur,and os acromiale didn’t show any association with rotator cuff tear. Acromio-humeral distance adjusted for the aforementioned variables showed statistically significant association with rotator cuff tear with AOR of 0.6;95% CI (0.41,0.89);p=0.01.