First carpometacarpal joint arthritis is a common condition encountered by hand surgeons. Traditionally, surgical approaches have included arthrodesis, trapeziectomy or reconstructive arthroplasty techniques. Previously, we described a technique for arthroscopic debridement and interposition arthroplasty of the first carpometacarpal joint. Patients with Eaton stages II and III symptomatic first carpometacarpal joint arthritis recalcitrant to >6 months of non-operative therapy underwent arthroscopic debridement of the first carpometacarpal joint with interposition of an acellular dermal matrix allograft (GRAFTJACKET™). In this paper, we describe outcomes following this procedure. Postoperatively, all patients reported symptomatic relief and 94% stated that they were partially, or completely, satisfied. More than 70% of patients reported no to mild difficulty in performing activities of daily living (average grip strength = 18.5 kg, pinch strength = 3.9 kg). Complications were minimal. Outcomes from this study compare favourably to those of other series, demonstrating that this technique is a viable option for treatment of Eaton stages II and III first carpometacarpal arthritis.