What Are the Most Clinically Effective Nonoperative Interventions for Thumb Carpometacarpal Osteoarthritis? An Up-to-date Systematic Review and Network Meta-analysis
Authors: Thakker Arjuna , Ramchandani Jai Parkash , Divall Pip , Sutton Alex , Johnson Nicholas , Dias Joseph 
Published: November 2024

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.