Changes in in vivo three dimensional shoulder kinematics following latissimus dorsi tendon transfer for irreparable posterosuperior rotator cuff tears: A systematic review with meta-analysis.

BACKGROUND: Latissimus dorsi transfer is a surgical procedure that can be used for treating posterosuperior rotator cuff tears. The procedure leads to improved shoulder function via alterations in the force vector couple around the shoulder. However, there is still no consensus on the biomechanical changes resulting from latissimus dorsi transfer.

METHODS: We performed a systematic review of the literature on 3D motion analysis studies evaluating the effects of latissimus dorsi transfer on shoulder kinematics. The available data on segment and joint range of motion was extracted and subject to meta-analysis when consistent across the studies.

FINDINGS: Our meta-analysis of pre- and post-operative studies revealed a significant improvement in forward flexion and abduction following latissimus dorsi transfer. When comparing the latissimus transferred shoulder with an uninjured contralateral side the meta-analysis found no significant difference in flexion range of motion, while abduction and external rotation was significantly higher in the uninjured shoulders. The overall risk of bias was moderate to high. High heterogeneity was found in the reporting of data, which limited our ability to perform a meta-analysis across the studies for all interest outcomes.

INTERPRETATIONS: Our findings suggest that latissimus dorsi transfer for posterosuperior rotator cuff tears effectively improves shoulder flexion and abduction. External rotation is also expected to improve but at inferior levels as compared to the unaffected side. However, the heterogeneity of the reported data on 3D motion analysis studies highlights the need for better standardization in research and reporting as to conclude the impact of different joints.