Addition of an Oblique Interfragmentary Screw to T-plate Fixation Decreases Nonunion Rate in Trapeziometacarpal Arthrodesis.

T-plate fixation is a popular method for trapeziometacarpal arthrodesis in patients with osteoarthritis. Previous studies report an 8% to 18% rate of symptomatic nonunion and a 26% rate of radiographic nonunion. In this study, we present our surgical technique of trapeziometacarpal arthrodesis using the addition of an oblique interfragmentary screw to T-plate fixation on the rate of symptomatic and radiographic nonunion. A retrospective review of all trapeziometacarpal arthrodeses for osteoarthritis was completed by a single surgeon between 2010 and 2018. Preoperative demographics, pain, and Eaton classification were included. The technique was identical in all surgical cases, using a T-plate and oblique interfragmentary screw across the arthrodesis site from the metacarpal to the trapezium. Postoperative nonunion rate and time to clinical healing (absence of pain) and radiographic union were reviewed. A total of 22 trapeziometacarpal arthrodeses were performed on 17 patients using the above technique. The average age was 53 years, 71% were women, and 53% involved the dominant hand. Mean preoperative Eaton classification was 2.74 (±0.73). Mean time to clinical healing was 34 days (±12 days), and mean time to radiographic union was 55 days (±23 days). Mean follow-up was 9 months, and no patients were found to have symptomatic or radiographic nonunion. Hardware removal was required bilaterally in 1 patient after complete healing. The addition of an oblique interfragmentary screw to T-plate fixation is a novel technique in trapeziometacarpal arthrodesis, resulting in no symptomatic or radiographic nonunion.