Axillary recess capsular edema is associated with heterogeneity in rehabilitation response: Implications for a magnetic resonance imaging-based stratified treatment strategy for adhesive capsulitis.

Abstract

To determine if axillary recess capsular edema on MRI is associated with heterogeneity in rehabilitation response for adhesive capsulitis and to explore its implications for a stratified treatment strategy. Retrospective cohort study. Department of Rehabilitation Medicine at a tertiary medical center. Thirty patients with adhesive capsulitis were stratified into two groups based on baseline MRI findings: a capsular edema negative (CE-) group (n=15) and a capsular edema positive (CE+) group (n=15). All patients received a standardized 2-week conventional rehabilitation program. Primary outcomes included the Shoulder Pain and Disability Index (SPADI), Visual Analog Scale (VAS) for pain, and active Range of Motion (ROM). Treatment efficacy was defined as achieving the minimal clinically important difference (MCID ≥14.88) in the total SPADI score. At baseline, the CE+ group demonstrated significantly worse VAS, ROM, and SPADI scores (P<0.05). Although both groups showed significant post-treatment improvements in all outcomes (P<0.001), the CE+ group exhibited significantly smaller improvements in SPADI and ROM (P<0.05). The MCID attainment rate was significantly lower in the CE+ group (53.33%) compared to the CE- group (93.33%). In an exploratory multivariate analysis, CE+ status was associated with a markedly lower odds of achieving the MCID (OR=0.043; 95%CI: 0.003 to 0.577; P=0.018). The presence of axillary recess capsular edema (CE+) on MRI is associated with more severe baseline dysfunction and a diminished early response to conventional rehabilitation in adhesive capsulitis. This MRI finding may identify a distinct patient phenotype. Our findings suggest a potential rationale for stratifying management: CE+ patients might benefit from augmented anti-inflammatory interventions, whereas CE- patients may be well-suited to standard adhesion-focused rehabilitation. This hypothesis warrants validation in prospective trials.