Is frozen shoulder completely resolved at 2 years after the onset of disease?

BACKGROUND: Although numerous studies have suggested that frozen shoulder (FS) is a self-limiting disease with most patients recovering within 2 years, its long-term outcome is still controversial. The aims of this study were to evaluate the clinical outcomes after conservative treatment for FS and to determine the predictors of its clinical outcome. METHODS: This study included 234 shoulders of 215 patients who received conservative treatment for FS. The mean follow-up period was 41.8 months (range 27-117 months). Initial evaluation included demographics, detailed medical history, and clinical assessments of shoulder status. Questionnaires, which included the Visual Analogue Scale (VAS) pain score, American Shoulder and Elbow Surgeons (ASES) score, Subjective Shoulder Value (SSV) and satisfaction grading for the current shoulder status were assessed at the final follow-up. RESULTS: The mean VAS pain score, ASES score, and SSV significantly improved from 6.7, 37.0, and 40.1% at the time of initial evaluation to 1.5, 87.6, and 85.0% at the final follow-up evaluation (all p < 0.001). According to satisfaction grading, the shoulder status at the final follow-up was very satisfied in 101 shoulders (43.2%), satisfied in 68 (29.1%), fair in 37 (15.8%), unsatisfied in 20 (8.5%), and very unsatisfied in 8 (3.4%). Univariate analysis revealed that gender, diabetes, simultaneous bilateral involvement, overall bilateral involvement and duration of symptoms were associated with clinical outcomes at the final follow-up. Multivariate analysis revealed that duration of symptoms (p = 0.002) was an independent risk factor for unsuccessful outcome. CONCLUSIONS: At the mean follow-up period of 41.8 months, 72.3% of patients revealed subjective satisfaction for the current shoulder status. Duration of symptoms was an independent risk factor for poor prognosis.