Study on proximal humerus evaluation of effective treatment (SPHEER) – what is the effect of rehabilitation compliance on clinical outcomes of proximal humerus fractures

INTRODUCTION: Proximal humeral fractures (PHFs) are 3(rd) commonest fragility fractures and cause significant functional impairment. This paper sought to determine impact of rehabilitation compliance on the clinical outcomes for non-surgically managed PHFs, while ascertaining reasons for non-compliance which can be addressed to improve compliance. METHODS: Prospective cohort study of patients undergoing non-surgical treatment for PHFs from August 2017 to April 2020 in a tertiary trauma centre was performed. Data was collected via questionnaire: patient demographic data, PHF injury details, clinical outcome measures, therapist-reported (Sport Injury Rehabilitation Adherence Scale [SIRAS]) and patient-reported (subjective compliance, frequency of exercise) rehabilitation compliance measures. Data was analysed using multiple linear regression model to account for confounding variables. RESULTS: 107 participants attended physical therapy follow-up for mean 137.8 days. 6-week SIRAS strongly predicted 3-month Constant score (p = 0.023; 95%CI = 0.265,3.423), OSS (p = 0.038; 95%CI = 0.049,1.634), flexion ROM (p < 0.001; 95%CI = 2.872,8.982), extension ROM (p = 0.035; 95%CI = 0.097,2.614), abduction ROM (p = 0.002;95%CI = 1.995,8.466) and achievement of functional active ROM at 3-months (p = 0.049; 95%CI = 1.001,1.638). Pain was the top reason impairing rehabilitation compliance from therapist (43.9% at 6-weeks and 20.6% at 3-months) and patient-perspective (33.6% at 6-weeks, 24.3% at 3-months). Author-developed patient-reported compliance measures had good correlation with validated SIRAS score (subjective compliance: p < 0.001 frequency of exercise: p = 0.001). CONCLUSION: Rehabilitation compliance predicts short-term clinical outcomes up to 3-months and potentially 1-year outcomes. Pain control should be optimised to maximise rehabilitation compliance and improve PHF outcomes. There is lack of consensus definition for rehabilitation compliance measures; patient-reported measures used have good correlation to existing validated measures and could serve as a steppingstone for further research. LEVEL OF EVIDENCE: II, cohort study. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12891-023-06894-w.