Morton's Neuroma (Interdigital Neuralgia) Treated with Metatarsal Sliding Osteotomy

Abstract

Background: Morton's neuroma is a common cause of metatarsalgia and many treatments had been described in literature. However, there have been only a few reports that treat the neuroma with an osteotomy on the proximal, not distal portion of the metatarsal bone using a plate. This study describes the clinical outcome of sliding osteotomy on the proximal metatarsal bone for the treatment of Morton's neuroma.

Materials and methods: Sixty five consecutive patients (85 feet) who underwent surgery for Morton's neuroma between November 2010 and February 2013 were identified from hospital records to include in this retrospective study. Average followup period was 37.3 months (range 24-51 months). Mean patient age at surgery was 50.2 years (range 23-75 years). Metatarsal sliding osteotomies were only performed on the third metatarsal bone. Clinical evaluations with the American Orthopaedic Foot and Ankle Society Lesser Metatarsophalangeal Interphalangeal Scale (AOFAS LMIS) and Foot Function Index (FFI) were performed. The length of the lesser toe was measured for radiologic evaluation.

Results: Postoperatively, AOFAS LMIS and FFI were improved from 52.1 (range 45-60) and 62.4 (range 54-73) to 74.2 (range 68-86) and 31.3 (range 26-37). At the last followup, preoperative pain was dissolved in 79 feet (93% of overall 85 feet). A shortened 3.2 mm (±1.1) metatarsal bone following osteotomy was radiographically measured. There were six cases of complications (soft tissue infection, early numbness, delayed union, limitation of dorsiflexion and metal failure, etc.).

Conclusions: This proximal metatarsal sliding osteotomy can be a relatively effective operative method in relieving pain from Morton's neuroma.

Keywords: Interdigital neuralgia; Morton's neuroma; Osteotomy; metatarsal sliding osteotomy; metatarsalgia; neuroma bone plates; plate; proximal metatarsal osteotomy.

Figure 1

A radiograph of foot anteroposterior view showing the method for the measurement of the metatarsal lengths of lesser toes. Metatarsal lengths were determined by the distances from the apex of each metatarsal to the transmetatarsal line crossed the center on the lateral sesamoid and perpendicular to the second metatarsal axis

Figure 2

A diagramatic representation of oblique osteotomy through the proximal half of the shaft of the metatarsal. It is important that the distal fragment should slide up and not angulate

Figure 3

A radiograph of foot anteroposterior view showing a sliding osteotomy for the third metatarsal bone. (a) Preoperative, (b) postoperative x-rays