Summary

the study provides a different perspective on the rc tear.

Abstract

Objective

The aim of this study was to evaluate the relationship between rotator cuff (RC) tear and humeral shaft-neck angle. In addition, preoperative X-ray and magnetic resonance imaging (MRI) measurements were compared with each other and the correlation between both measurements was evaluated.

Method

The study group consisted of 28 patients with RC tears (13 males, 15 females). Thirty patients (14 males, 16 females) of similar age and gender without rotator cuff tear were randomly selected and formed the control group. The humeral shaft-neck angles of patients with torn rotator cuff and patients with intact rotator cuff were measured. Measurement of the humeral shaft-neck angle was performed both on direct radiographs and MRI. The correlation between both measurements was evaluated.

Results

The mean ages of the patient groups with and without RC tear were 47.8±8.3 years and 48.3±7.6 years, respectively. (p>0.05) The mean retraction amount of the patients with RC tear was 2.7±1.8 mm. The humeral shaft-neck angle of the patient group with RC tear was 153.7°±6.9° on x-ray and 149.2°±7.4° on MRI. The humeral shaft-neck angle of the patient group with intact RC was 146.3°±6.4° on x-ray measurement and 143.4°±6.3° on MRI measurement. There was a statistically significant difference between the two groups in terms of humeral shaft-neck angles (p<0.001, p<0.05, respectively). It was observed that the humeral shaft-neck angle was more valgus in patients with RM tear. Preoperative x-ray and MRI measurements showed a moderate-high correlation between both measurements (p<0.01, r=0.684).

Conclusion

Patients with RC tears had a higher humeral shaft-neck angle compared to patients without tears. This suggests that patients with higher shaft-neck angle are more prone to tear formation and valgus is a predisposing factor for RC tear.