Optimal time for manipulation of frozen shoulder may be between 6 and 9 months

Background and Aims: Idiopathic frozen shoulder can be successfully treated conservatively. Manipulation under anesthesia, in randomized controlled studies, has proven to bring no additional benefit to other treatments. However, manipulation under anesthesia still is a used method mainly among patients with unbearable pain or too longstanding restriction of shoulder motion. Manipulation under anesthesia may lead to significant improvement in shoulder motion and function. However, the best timing for manipulation under anesthesia is still unclear. We therefore investigated whether timing of manipulation under anesthesia has influence on the results of manipulation under anesthesia, concerning range of motion, pain, and function. Material and Methods: We followed 57 patients (65 shoulders; 31 in women) at 2-14years after manipulation under anesthesia evaluating range of motion, pain, and function. Their mean age at manipulation under anesthesia was 54.0years. A total of 10 patients had diabetes. The time between the onset of symptoms and manipulation averaged 8.8months. We formed two groups, those mobilized between 6 and 9months after the onset of symptoms (Group A, 25 shoulders), and the others (Group B, 40 shoulders). We recorded visual analog scale pain, range of motion, Simple Shoulder Test, and Constant-Murley scores. Results: Patients manipulated between 6 and 9months after the onset of symptoms had significantly better abduction and external rotation, less pain at rest and at night, and better Simple Shoulder Test than the others. Conclusions: It seems that timing has statistically significant influence on results of manipulation of the idiopathic frozen shoulder. The best time for manipulation under anesthesia, if non-operative treatment has failed to alleviate pain or limitation of shoulder motion is too cumbersome, might be between 6 and 9months from the onset of the symptoms. However, the clinical importance of results can be questioned.