A morphometric study of skeletal and soft tissue components of the glenohumeral joint associated with shoulder pathologies

Abstract

Abstract Morphological traits pertaining to the humerus and scapula have previously been linked to the occurrence and perhaps development of certain shoulder pathologies such as, osteoarthritis, rotator cuff impingement and chronic shoulder dislocations. Few studies have investigated these traits in a South African sample and therefore the aim of this study was to investigate the differences in various skeletal and soft tissues components of the glenohumeral joint (GHJ) in individuals with known or diagnosed shoulder pathology. The sample included a cadaveric (n=46), X-ray (n=94) and MRI (n=46) component. In the cadaver component, only 11 presented with shoulder pathology, while all the individuals in the imaging component (X-ray and MRI) presented with known/diagnosed shoulder pathologies. Several measurements and observations were taken and included; acromial type (AT), intertubercular groove width (ITGW), glenoid fossa depth (GFD), acromial index (AI), lateral acromial angle (LAA), acromioclavicular joint distance (ACJ), acromiohumeral distance (AHD), glenoid fossa length (GFL), maximum humeral head diameter (HHMax_dia), humeral angle of inclination (HHI) and presence/absence of pathology. The results indicated that males had a higher occurrence of AT I than AT II and the females an even ratio between AT I and AT II in the X-ray and cadaveric component, while black males in the X-rays had a higher occurrence of AT II than AT I. In both the X-ray and MRI samples, female groups showed a higher occurrence of AT I than AT II. Significant differences in morphology of the AI, ACJ, LAA, HHI and GHD were noted between the various acromial types (I, II, III). The HHMax_dia was the only morphometric variable that showed significance differences across all three samples (cadaver, X-ray and MRI). The AI, LAA, GFL showed significant morphological differences in both the X-ray and MRI groups, the HHI and ACJ only showed significant differences in the X-ray group, while the GH only showed differences in the MRI group. The results gained in this study suggest that AT, AI, ACJ, LAA, HHMax_dia, HHI, GHD and GFL in individuals with known or diagnosed shoulder pathologies such as chronic joint instability, osteoarthritic and osteoporotic changes, rotator cuff pathologies, frozen shoulder/adhesive capsulitis and tendinopathy/calcific tendinitis, are different from no-pathology individuals and these traits may provide more insight, if studied further, into the development of shoulder pathology.