Corticosteroid Injection Methods for Frozen Shoulder: A Network Meta-analysis

To investigate the efficacy of corticosteroid injection methods for frozen shoulder.PubMed, Embase, and Cochrane Library were searched up to 6th May 2023.Randomized controlled trials (RCTs) that investigated corticosteroid injection methods for frozen shoulder were included.Data were extracted independently by two authors. Risk of bias was assessed using the RoB 2 tool.A random-effects network meta-analysis was performed within a frequentist framework. The certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations approach. A total of 66 RCTs involving 4491 patients were included. For short-term outcomes, 4-site injection (vs placebo: SMD = -2.20, 95% CI: -2.81 to -1.59 in pain; SMD = 2.02, 95% CI: 1.39 to 2.65 in global function) was the most effective (low certainty). Rotator interval injection was the optimal treatment with moderate to high certainty (vs placebo: SMD = -1.07, 95% CI: -1.51 to -0.64 in pain; SMD = 0.94, 95% CI: 0.49 to 1.40 in global function). For midterm outcomes, 4-site injection was most effective (vs placebo: SMD = -1.71, 95% CI: -2.41 to -1.01 in pain; SMD = 2.22, 95% CI: 1.34 to 3.09 in global function; low certainty). Distension via rotator interval was the optimal treatment with moderate to high certainty (vs placebo: SMD = -1.10, 95% CI: -1.69 to -0.51 in pain; SMD = 1.46, 95% CI: 0.73 to 2.20 in global function). Distension and intra-articular injection via anterior or posterior approaches produced effects equivalent to those of rotator interval injection and distension via rotator interval.Rotator interval injection, distension, and intra-articular injection had equivalent effects on symptom relief. More RCTs are required to validate the superiority of multisite injections.