Coracoid morphology and humeral version as risk factors for subscapularis tears.

BACKGROUND: The pathophysiology of subscapularis (SS) lesions is still relatively unknown despite recent interest in predictive factors for SS tears. Our goal was to determine the influence of the coracoid morphology and humeral version on SS tears. METHODS: This was a retrospective, controlled, single-blinded study. We analyzed 232 shoulders with SS lesions confirmed by magnetic resonance imaging. The coracoid proximal length, coracoid distal length (CLD), and coracoid total length were measured. The coracoid length ratio, coracoid angle (CA), and humeral version were also evaluated. RESULTS: We found that greater humeral retroversion was progressively related to more serious SS injuries, with values of -28.6° ± 19.5° and -51.0° ± 11.1° in the normal SS group and tear group, respectively (P < .001). The same tendency was shown for the CA, with values of 123.8° ± 11.1° in the control group vs. 97.4° ± 10.1° in the tear group (P < .001). Greater CLD, coracoid total length, and coracoid length ratio were also associated with an increased risk of SS tears (P < .001). The CA and CLD represented the best predictors of SS tears, presenting areas under the receiver operating characteristic curve of 90.0% and 89.0%, respectively. CONCLUSIONS: This article is the first to study the influence of different parameters of the coracoid process morphology and humeral version on SS tears. We proved that humeral version and coracoid morphology were important risk factors for SS pathology and could accurately predict these lesions. Finally, our study was the first to create a classification system to divide coracoids according to their morphology and relative risk of associated SS tears.

Coracohumeral distance and coracoid overlap as predictors of subscapularis and long head of the biceps injuries.

BACKGROUND: Subscapularis (SS) lesions are often underdiagnosed because of an incomplete understanding of contributing factors but also because of a greater difficulty in SS tear diagnosis with magnetic resonance imaging or physical examination. In this setting, predicting factors can be useful tools in these injuries' management. The goal of this study was to determine the influence of the coracohumeral distance (CHD) and coracoid overlap (CO) in anterior rotator cuff lesions, as well as to determine the CHD and CO values that can accurately predict SS and long head of the biceps (LHB) injuries. METHODS: We performed a retrospective, controlled, single-blinded study. We analyzed 301 patients with rotator cuff pathology and magnetic resonance imaging studies; patients with SS lesions represented the study group. The CHD and CO were measured. RESULTS: We found that lower CHD and higher CO values were progressively related to more serious injuries of the SS and LHB. The CHD was a very strong predictor of SS injury and tear and a good predictor of LHB injuries. A CHD of 7.6 mm had a sensitivity of 84.4% and specificity of 88.6% for SS tears. The CO was also a very strong predictor of SS tears and a good predictor of LHB injury, with a CO of 16.6 mm reaching a sensitivity of 77.8% and specificity of 68.3% for SS tears. CONCLUSIONS: The CHD is an excellent predictor of SS tears and a good predictor of LHB lesions, with the CO also being a very strong predictor of SS tears and a good model for LHB injuries.

Computed tomography morphological analysis of the scapula and its implications in shoulder arthroplasty.

BACKGROUND: Healthy shoulder morphology is still unclear. Since bone morphology influences prosthetic features, this is relevant for glenohumeral joint reconstruction. The objective of this study was to assess the normal values of glenoid version, maximum width, base width and vault depth on computed tomography scans. METHODS: Axial cut CT scans of 1072 healthy glenoids were retrospectively reviewed. Values of glenoid version, maximum glenoid width, glenoid base width and glenoid vault depth were measured by two different observers. Differences were determined between genders, and reproducibility and interrater reliability assessed. RESULTS: Glenoid version was 37.71° ± 10.75°, range -6.20° to 71.30°; maximum glenoid width was 26.06 ± 3.27 mm, range 15.40-36.90 mm; glenoid base width was 16.59 ± 2.61 mm, range 8.90-25.40 mm; glenoid vault depth was 9.72 ± 1.62 mm, range 4.70-15.90 mm. All measurements except for glenoid version were significantly higher in males than in females. Reproducibility was good for every measurement, except glenoid vault depth. CONCLUSION: We found differences in maximum glenoid width, base width and vault depth by gender in a large sample. Glenoid components' maximum width was defined, as was reaming extension and orientation, the space available for implantation of the glenoid component, placement of pegs or keels in anatomic prostheses and the target for glenoid screws in inverted prostheses. LEVEL OF EVIDENCE: II.