What Are the Most Clinically Effective Nonoperative Interventions for Thumb Carpometacarpal Osteoarthritis? An Up-to-date Systematic Review and Network Meta-analysis.

Background: Thumb carpometacarpal osteoarthritis (CMC-1 OA) is a common and debilitating condition, particularly among older adults and women. With the aging population, the prevalence of CMC-1 OA is expected to rise, emphasizing the need to find effective nonoperative strategies. So far, for determining the most effective nonoperative interventions in CMC-1 OA, two network meta-analyses (NMAs) have been published. However, these NMAs were limited to specific intervention types: one comparing multiple splints and the other comparing different intraarticular injections. Therefore, an NMA that compared all nonoperative intervention types is urgently needed.

Questions/purposes: This study aimed to assess and compare the effectiveness of available nonoperative interventions (both nonpharmacologic and pharmacologic) for CMC-1 OA to establish which nonoperative options are more effective than control in terms of (1) pain, (2) function, and (3) grip strength.

Methods: We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) NMA guidelines (PROSPERO: CRD2021272247) and conducted a comprehensive search across Medline, Embase, CENTRAL, and CINAHL up to March 2023. We included randomized controlled trials (RCTs) and quasi-RCTs evaluating nonoperative interventions for symptomatic CMC-1 OA, excluding inflammatory or posttraumatic arthritis. Studies comparing ≥ 2 interventions or against a control, focusing on pain reduction, functional improvement, and grip strength, were selected. We assessed methodologic quality using the modified Coleman Methodology Score, including only studies scoring > 70. Risk of bias was evaluated with the Risk of Bias 2.0 tool, and evidence quality with Confidence in Network Meta-Analysis (CINeMA). Of 29 screened studies, 22 (21 RCTs and one quasi-RCT) were included, involving 1631 women and 331 men. We analyzed eight different nonoperative interventions, including splints, hand exercises, injections, and multimodal treatment (≥ 2 nonpharmacologic interventions or nonpharmacologic with a pharmacologic intervention). Six studies had a low risk of bias, eight had a high risk, and the remainder were moderate. We extracted mean and SD scores, and NMA and pairwise analyses were performed at short- (≤ 3 months) and medium-term (> 3 to ≤ 12 months) time points. Standardized mean differences were re-expressed into common units for interpretation, which were the VAS (range 0 to 10) for pain, the DASH test (range to 100) for function, and pounds for grip strength. Clinical recommendations were considered strong if the mean differences exceeded the minimum clinically important difference-1.4 points for VAS, 10 points for DASH, and 14 pounds for grip strength-and were supported by moderate or high confidence in the evidence, as assessed using CINeMA methodology.

Results: Our NMA (based on moderate or high confidence) showed a clinically important reduction in pain at the short-term time point for multimodal treatment and hand exercises versus control (mean difference VAS score -5.3 [95% confidence interval (CI) -7.6 to -3.0] and -5.0 [95% CI -8.5 to -1.5]). At the medium-term time point, only the rigid carpometacarpal-metacarpophalangeal (CMC-MCP) splint was superior to control (mean difference VAS score -1.9 [95% CI -3.1 to -0.6]) and demonstrated clinical importance. For function, only the rigid CMC-MCP splint demonstrated a clinically important improvement at the medium-term time point versus control (mean difference DASH score -11 [95% CI -21 to -1]). Hand exercises resulted in a clinically important improvement in short-term grip strength versus control (mean difference 21 pounds [95% CI 11 to 31]).

Conclusion: This systematic review and NMA show that multimodal treatment and hand exercises reduce short-term pain and improve grip strength, while a rigid CMC-MCP splint enhances medium-term function. Future research should evaluate long-term efficacy.

Level of evidence: Level I, therapeutic study.