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

Abstract

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. 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. 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 (<i>p</i> < 0.01 for each pairwise comparison). 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.