Association Between Postoperative Subacromial Impingement Syndrome and Functional Recovery After Arthroscopic Rotator Cuff Repair in Elderly Patients: A Single-Center Retrospective Study.

PURPOSE: To investigate the clinical characteristics of postoperative subacromial impingement syndrome (SIS) in elderly patients undergoing arthroscopic rotator cuff repair (RCR) and to analyze its association with mid- to long-term postoperative functional recovery.

METHODS

A retrospective analysis was conducted on the clinical data of 150 elderly patients who underwent RCR between January 2023 and January 2025. Patients were stratified into an impingement group (n = 32) and a non-impingement group (n = 118) based on the presence of SIS at 3 months postoperatively. Preoperative baseline characteristics, surgery-related variables, and postoperative outcomes including the Constant-Murley Shoulder Score (CMS), the University of California, Los Angeles Shoulder Score (UCLA), and the Visual Analog Scale for pain (VAS) were compared between the two groups at 3, 6, and 12 months after surgery.

RESULTS

At 3 months postoperatively, the incidence of SIS was 21.33% (32/150). The affected patients mainly presented with aggravated shoulder pain during abduction and forward flexion, with 100% positive Neer impingement test and 90.63% positive Hawkins impingement test, and some patients had audible clicking during shoulder movement. At 3, 6, and 12 months after surgery, CMS and UCLA scores were significantly lower in the impingement group than in the non-impingement group, while VAS scores were significantly higher (all P < 0.05), Cohen's d values for CMS at 0.55, 0.35, 0.59; for UCLA at 1.21, 0.41, 0.48; and for VAS at 0.42, 0.81, 0.63 (moderate to large effect sizes) indicating a substantial magnitude of intergroup differences. Although CMS and UCLA scores demonstrated a progressive improvement over time and VAS scores showed a continuous decline in both groups, the overall recovery level in the impingement group remained consistently inferior to that of the non-impingement group throughout the follow-up period.

CONCLUSION

The incidence of SIS after RCR in elderly patients is relatively high, and the postoperative SIS in this population is characterized by aggravated shoulder pain during abduction and forward flexion, positive Neer and Hawkins impingement tests, and occasional audible clicking during shoulder movement. Postoperative SIS was significantly associated with poorer shoulder functional recovery and delayed pain relief in elderly patients undergoing arthroscopic rotator cuff repair.