Shoulder Proprioception Following Reverse Total Shoulder Arthroplasty for Unreconstructable Upper Third Fractures of the Humerus: 2-Year Outcomes.

Background: Proximal humerus fractures may be comminuted in the elderly or after injury with high-energy mechanisms. Reverse total shoulder arthroplasty that may affect shoulder proprioception (rTSA) has also begun to play a part in treating acute proximal humeral fractures. In this study, the authors aimed to evaluate joint position sense (JPS) after rTSA.

Methods: Humac Norm II isokinetic device was used to evaluate the joint position sense. A joint angle was determined and the ability of the patient to create the same value of the angle by the active movement was evaluated. The difference between the pre-determined angle and the patient's measured angle was recorded. For proprioceptive sense, the initial position was 0° and the determination position was 30°, 60°, and 90° for flexion and abduction, and 15° and 30° for internal rotation and external rotation.

Results: While both the mean Constant and ADLEIR scores did not differ between non-operated and operated sides, the mean proprioception differences in all flexion (30°, 60°, and 90°), abduction (30°, 60°, and 90°), internal rotation (15° and 30°), and external rotation (15° and 30°) were significantly higher in the operated side than that in non-operated side ( < 0.01 for each pairwise comparison).

Conclusion: Reverse total shoulder arthroplasty (rTSA) treatment, which has increasingly become a surgical option in un-reconstructable proximal humeral fractures has significant adverse effects on proprioception on the operated side and may pose a risk for long-term instability, premature loosening, and prosthesis mechanical complications, in this context, well-designed prospective controlled studies are required.