Thresholds for diminishing returns in postoperative range of motion after total shoulder arthroplasty

• Published in: Journal of shoulder and elbow surgery
• Main Authors: Hao, Kevin A., Kakalecik, Jaquelyn, Wright, Jonathan O., King, Joseph J., Wright, Thomas W., Simovitch, Ryan W., Vasilopoulos, Terrie, Schoch, Bradley S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 09.07.2024
• Subjects: Anatomic total shoulder; clinical outcome; inverted shoulder; patient-reported outcome; reverse shoulder; reverse total shoulder; shoulder replacement; Anatomic total shoulder; reverse shoulder; inverted shoulder; Validation of Outcome Measures; clinical outcome; Basic Science Study; reverse total shoulder; patient-reported outcome; shoulder replacement; anatomic total shoulder
• ISSN: 1058-2746; 1532-6500; 1532-6500
• DOI: 10.1016/j.jse.2024.05.022

Satisfaction following total shoulder arthroplasty (TSA), which is commonly reported using patient-reported outcome measures (PROMs), is partially dependent upon restoring shoulder range of motion (ROM). We hypothesized there exists a minimum amount of ROM necessary to perform functional tasks queried in PROM questionnaires, beyond which further ROM may provide no further improvement in PROMs. A retrospective review of a multicenter international shoulder arthroplasty database was performed between 2004 and 2020 for patients undergoing anatomic or reverse TSA (aTSA, rTSA), with minimum 2-year follow-up. Our primary outcome was to determine the threshold in postoperative active ROM (abduction, forward elevation [FE], external rotation [ER], and internal rotation [IR] score), whereby additional improvement was not associated with additional improvement in PROMs (Simple Shoulder Test, American Shoulder and Elbow Surgeons score, and the Shoulder Pain and Disability Index). For comparison, we also evaluated the Shoulder Arthroplasty Smart (SAS) score, which is not subject to the ceiling effect. We included 4459 TSAs (1802 aTSAs, 2657 rTSAs) with minimum 2-year follow-up (mean, 56 ± 32 months). The threshold in postoperative ROM that were associated with no further improvement were active abduction, 107-113° for PROMs vs. 163° for the SAS score; active FE, 149-162° for PROMs vs. 176° for the SAS score; active ER, 50-52° for PROMs vs. 72° for the SAS score; IR score, 4-5 points for all PROMs vs. 6 points for the SAS score. Out of 3508 TSAs with complete postoperative ROM data, 8.5% achieved or exceeded all ROM thresholds (14.5% aTSAs, 4.8% rTSAs). Our findings demonstrate that postoperative ROM exceeding 113° of abduction, 162° of FE, 52° of ER, and IR to L1 is associated with minimal additional improvement in PROMs. While individual patient needs vary, the thresholds may provide helpful targets for patients undergoing postoperative rehabilitation.