Learning curve for trapeziometacarpal joint implant arthroplasty: case volume needed to achieve proficiency

This study analysed the learning curve of trapeziometacarpal joint implant arthroplasty using the cumulative sum (CUSUM) method. A total of 338 patients underwent trapeziometacarpal joint arthroplasty with the Touch® prosthesis, performed by two expert surgeons (A, B) and one less experienced specialist (C). Surgical proficiency was achieved at case 33 for surgeon A and B, and case 40 for surgeon C. Mean surgery times were 39 min (SD 9), 43 min (SD 6) and 59 min (SD 19), respectively. Two-year clinical and patient-reported outcomes and revision rates were not worse for patients who underwent surgery before achieving proficiency. These findings indicate a considerable learning curve for trapeziometacarpal joint implant arthroplasty, with experienced surgeons achieving proficiency more quickly. Although outcomes before reaching the learning curve did not differ from those operated on later, we recommend comprehensive training when introducing this procedure and a high case volume to improve surgical skills.<b>Level of evidence:</b> IV.