The carpometacarpal (CMC) joint is the most common joint in the hand and wrist to undergo surgery. Several different surgical treatments have been proposed, but it remains unclear which approach results in the best outcomes and highest patient satisfaction. One approach is the use of human acellular dermal matrix (HADM) for interposition after trapeziectomy.1 The purpose of the study is to prospectively compare use of HADM for interposition arthroplasty to trapeziectomy alone.
Thirty patients with Eaton stage III and IV CMC arthritis were enrolled in the study. Seven patients made up the control group of trapeziectomy alone, and 23 patients underwent interposition arthroplasty with HADM to comprise the study group. The groups were frequency matched for age, female to male ratio, Eaton Stage, and prior intervention. Similarity between the groups was confirmed with independent t test for continuous variables and chi-squared for categorical variables (Table 1). Patients’ Disability of the Shoulder, Arm and Hand (DASH) and Wong Baker pain scale scores were recorded with validated, standardized survey instruments2,3 at each visit, and grip and pinch strength were recorded by the same blinded hand therapist at each session. Arthroplasty space was calculated by the distance between the distal pole of the scaphoid and the proximal surface of the thumb metacarpal divided by the length of the thumb metacarpal4 and was obtained from radiographs taken at each visit. Preoperative and postoperative scores were compared at 6 weeks, 6 months, and 1 year with paired t test.
Mean preoperative and 1-year follow-up measures are summarized in Table 2. Study measures improved comparably across both groups. At last follow-up, arthroplasty space was maintained in all patients. There were no complications or adverse reactions associated with the HADM, and no patients required revision in either group.
To our knowledge, this is the only prospective study comparing trapeziectomy alone to interposition arthroplasty with HADM. Prior meta-analysis has failed to show definitive proof of the superiority of any particular surgical approach over another for CMC arthritis,5 and our own study is unable to demonstrate clear superiority of either technique examined. Nonetheless, our findings show HADM interposition to be at least comparable to trapeziectomy, although a major limitation of the study is its small sample size, and therefore, the possibility of type B error cannot be excluded. Cost of the HADM is another limitation to the approach, and further data collection is ongoing to evaluate the durability of both methods over time and to determine whether long-term functionality might justify the initial cost of the allograft. Still, early results suggest that interposition with HADM may offer a safe and effective method of maintaining trapezial height, restoring a functional, painless hand and improving strength while also providing an alternative material to avoid donor-site morbidity or a substitute in revision cases where the surgeon’s preferred autograft may already have been used. Ongoing study is warranted to determine the durability of these results over time.
1. Yao CA, Ellis CV, Cohen MJ, et al. Preserving the posttrapeziectomy space with a human acellular dermal matrix spacer: a pilot case series of patients with thumb carpometacarpal joint arthritis. Plast Reconstr Surg Glob Open. 2013;1:e65.
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4. Yang SS, Weiland AJ. First metacarpal subsidence during pinch after ligament reconstruction and tendon interposition basal joint arthroplasty of the thumb. J Hand Surg Am. 1998;23:879–883.
5. Wajon A, Vinycomb T, Carr E, et al. Surgery for thumb (trapeziometacarpal joint) osteoarthritis. Cochrane Database Syst Rev. 2015; 23;(2):CD004631.