Stabilization of the subluxed second metatarsophalangeal joint: flexor tendon transfer versus primary repair of the plantar plate.

Surgical treatment of the subluxed second metatarsophalangeal joint (MTPJ) has been a consistently frustrating problem for the foot and ankle surgeon. The plantar plate is the principal stabilizing structure of the second MTPJ and compromise to its integrity has been implicated as the cause of the subluxed second toe. Flexor tendon transfer has been reported as the mainstay of treatment to stabilize the subluxed second MTPJ. Recently, primary repair of the plantar plate has been advocated, yet no research exists comparing it to flexor tendon transfer. Eight freshly frozen lower extremity cadaver specimens were mounted on a custom-fabricated load frame. A vertical dorsally directed force was applied to the base of the proximal phalanx of the second toe via a pneumatic actuator to stimulate the Lachman test. Dorsal displacements of the proximal phalanx were measured with a linear variable distance transducer. This investigation examined the comparative strength of flexor tendon transfer versus primary repair of the plantar plate in stabilizing the second MTPJ. Results showed a significant difference between the transected plantar plate and the intact plantar plate. Displacements for the repair groups were similar to the intact plantar plate group and also significantly different from the transected plantar plate. Primary repair of the plantar plate is a viable alternative to flexor tendon transfer in stabilizing the second MTPJ with the advantage of addressing the pathology anatomically. Clinical studies are needed to substantiate these laboratory findings.