Combined Plantar Plate and Hammertoe Repair with Flexor Digitorum Longus Tendon Transfer for Chronic, Severe Sagittal Plane Instability of the Lesser Metatarsophalangeal Joints: Preliminary Observations

Abstract

The plantar plate provides a substantial static support for the lesser metatarsophalangeal joints. Insufficiency involving tear, attenuation, or absence of this structure can result in significant sagittal plane instability and deformity. When a plantar plate tear is established and is unresponsive to conservative treatment, plantar plate repair is indicated to address symptoms and reestablish static joint stability. The authors hypothesized that combined plantar plate and hammertoe repair with flexor digitorum longus tendon transfer provides a viable surgical option to address chronic plantar plate tears with secondary joint instability and digital deformity. The authors retrospectively evaluated a case series of 18 consecutive patients (20 feet) who underwent this combined surgical strategy as the primary procedure to address severe, chronic sagittal plane instability of the lesser metatarsophalangeal joints. Other procedures were performed concurrently in all cases to address predisposing factors and concomitant deformities. Method of evaluation included a subjective, objective, and radiologic evaluation performed at least 1 year after their surgical procedure. Two rating systems were used: the Lesser Metatarsophalangeal-Interphalangeal Scale from the American Orthopedic Foot and Ankle Society, and another designed by the authors. The average postoperative American Orthopedic Foot and Ankle Society score was 83.2/100 and the average postoperative score with the authors' rating system was 87.7/100. All patients were satisfied with their postoperative result. Study results suggest combined plantar plate and hammertoe repair with flexor digitorum longus tendon transfer to be a viable option to address severe, chronic sagittal plane instability of the internal lesser metatarsophalangeal joints. ACFAS Level of Clinical Evidence: 4.