Background: Reverse total shoulder arthroplasty (RSA) can improve function in cuff tear arthropathy (CTA) shoulders, but limited exact data are available about the maximum values in 3D motion analysis, and as to how improvements translate into the normal range of motion (ROM) in activities of daily living (ADLs).
Methods: This study included nine consecutive patients (n = 9) who received RSA for CTA without muscle transfers. We measured shoulder movement by a novel 3D motion analysis using the Heidelberg upper extremity model (HUX) which can eliminate compensatory movements of the scapula, and the trunk. The measurement included active maximum values, and four ADLs.
Results: Comparing the pre- to the 1-year postoperative status, RSA was associated with a significant increase in the mean maximum values for active flexion of about 43° (SD ± 31) from 66° to 109° (p = 0.001), for active abduction of about 37° (SD ± 26) from 57° to 94° (p = 0.001), and for the active adduction of about 28° (SD ± 10) from 5° to 33° (p = 0.002). Comparing the preoperative to the postoperative ROM in the ADLs in flexion/extension, ROM improved significantly in all ADLs, in abduction/adduction in three of four ADLs. No significant changes were observed in internal/external rotation in any ADLs.
Conclusion: RSA improves the active maximum ROM for flexion, abduction, and adduction. The patients are able to take advantage of this ROM increase in ADLs in flexion and in most ADL in abduction, but only in trend in internal and external rotation.