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

OBJECTIVE: To investigate the efficacy of corticosteroid injection methods for frozen shoulder.

DATA SOURCES: PubMed, Embase, and Cochrane Library were searched up to 6th May 2023.

STUDY SELECTION: Randomized controlled trials (RCTs) that investigated corticosteroid injection methods for frozen shoulder were included.

DATA EXTRACTION: Data were extracted independently by two authors. Risk of bias was assessed using the RoB 2 tool.

DATA SYNTHESIS: 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.

CONCLUSIONS: 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.