Rotator Cuff Tears and Mid-Term Shoulder Outcomes after Intramedullary Nail Fixation for Humeral Shaft Fracture: A Minimum Five-year Follow-up Study.

Introduction: Antegrade intramedullary nail fixation for humeral shaft fractures yields satisfactory union rates. However, one of the related concerns is damage to the rotator cuff during nail insertion, which may affect long-term outcomes. The effect of a rotator cuff lesion on mid- and long-term shoulder outcomes remains unknown. This study aimed to investigate the incidence of rotator cuff tears 5 years or more after intramedullary nailing for humeral shaft fractures and to determine the impact of post-operative rotator cuff tears on mid-term outcomes.

Material and methods: We retrospectively identified 27 patients who underwent antegrade intramedullary nail fixation for traumatic humeral shaft fractures and received follow-up for at least 5 years post-operatively. The patients were divided into two groups: those without tears and those with partial or complete tears, diagnosed using ultrasonography. We compared the functional and radiological shoulder outcomes between the two groups.

Results: Of the 27 patients, 10 had partial or complete supraspinatus tears with a mean follow-up of 7.5 years postoperatively. The incidence of acromial spurs was significantly higher in patients with partial or complete tears than in those without tears (P<0.001). There were no significant differences in the age and sex-adjusted Constant score, or the American Shoulder and Elbow Surgeon score between the two groups.

Conclusion: Our results revealed that 37% of patients developed partial or complete supraspinatus tendon tears in the mid-term. Post-operative rotator cuff tears were significantly associated with the formation of acromial spurs; however, they had no significant effect on mid-term shoulder functional outcomes.