The authors retrospectively reviewed 9 patients (16 digits) who underwent an extensor splitting approach to the proximal interphalangeal (PIP) joint for silicone implant arthroplasty in the treatment of osteoarthritis. The technique involved repairing the extensor tendon but without reinserting the central slip into the base of the middle phalanx. The finger was immobilized in extension for 2 weeks followed by use of a dynamic PIP joint extension splint for 2 weeks. At a mean follow-up of 23 months, 14 digits had no extensor lag, while 2 digits had an extensor lag of 20 to 25 degrees. The average final arc of PIP joint motion was 61 degrees (the preoperative arc of motion was not reported).
Most dorsal approaches to the PIP joint are designed to preserve or repair the central slip attachment. Preserving the central slip attachment, however, may compromise access to the middle phalanx base for implant arthroplasty. Furthermore, reattaching the central slip may unintentionally shorten the central tendon and alter the balance of the extensor mechanism. The findings from this study support surgical detachment of the central slip during PIP joint silicone implant arthroplasty.