Preserving the posttrapeziectomy space with a human acellular dermal matrix spacer: a pilot case series of patients with thumb carpometacarpal joint arthritis.

There is no consensus regarding treatment for late-stage thumb carpometacarpal (CMC) arthritis.1 Trapeziectomy alone leaves a postresection space that allows proximal metacarpal migration and possible scaphoid/trapezoid impingement, with a markedly narrow joint space under stress.2 Although scaphoid impingement is a commonly cited but rarely documented complication, a reduced joint space is universally expected and loss of strength and stability and pain are known complications.3,4 Numerous studies show satisfactory functional outcomes for autologous tissue interposition with or without ligament reconstruction. Joint height is reduced by 50% after 12–36 months although patients tend to have adequate pain relief for many years.5,6 Using the flexor carpi radialis tendon for ligament reconstruction and tendon interposition improves strength, pain, function, and patient satisfaction,7–9 and loss of arthroplasty height was 11–13% on long-term follow-up.10,11 Patients occasionally reported increased postoperative pain, FCR tendonitis, and decreased fatigue strength.6 Autograft procedures require more operative time and extensive dissection that leads to increased scarring and pain and altered wrist kinetics. Naidu et al12 showed that FCR tendon harvesting leads to a significant decrease in the wrist flexion extension torque ratio and wrist flexion fatigue resistance. Variations of the LRTI include recreating of the volar beak ligament with the abductor pollicis longus13,14 or abductor pollicis brevis.15 Although these studies cite satisfactory pain improvement, trapezial space loss was 14–32%. “Double arthroplasty” using the distal FCR and flexor carpi ulnaris has significant morbidity from tendon harvests. Costochondral allograft technique by Trumble et al16 had a trapezial height loss of over 21% after 1 year. Without clear benefits, complex autograft interposition can be associated with increased donor-site morbidity, scar tenderness, tendon adhesion or rupture, sensory changes, and complex regional pain syndrome.17 Early attempts at nonautologous interposition grafts were unsuccessful. A 2001 human trial of trapeziectomy alone versus trapeziectomy with porcine xenograft (Permacol) interposition was aborted because 6 of the 13 interposition patients developed joint space collapse with subluxation and adduction deformities. Patients had persistent histologically proven graft reactions, resulting in greater pain and erythema.18 In 1998, Muermans and Coenen19 used Gore-Tex (expanded polytetrafluroethylene) and Marlex (polypropylene) as interposition material to find that 3 out of 10 patients with Gore-Tex had significant synovitis requiring explantation. Although the Marlex group had similar results to the tendon interposition control group, Marlex is not regularly used today. Newer allografts have shown promise. Trapezial space preservation was successful in a rabbit model in 2007 using acellular dermal matrix20 and in a monkey model21 in 2000 using allogenic tendon. In humans, Kokkalis et al22 used human acellular dermal matrix (HADM) to reconstruct the palmar beak ligament and fill the posttrapeziectomy space. At 12 months, they reported significantly less pain, increased grip and pinch strength (16% and 19%, respectively), 31% reduction in arthroplasty space, and no adverse reactions. Adams et al23 described arthroscopic debridement of the first CMC joint with HADM interposition arthroplasty. They reported improved pain and grip strength and high patient satisfaction with no complications. Taghinia et al24 proposed a suspended cadaveric fascia lata interposition allograft but reported a 50% loss of trapezial height despite satisfactory functional outcomes. To address current allograft shortcomings, the senior author proposes a novel technique.