Concurrent interdigital neuroma and MTP joint instability: long-term results of treatment.

INTRODUCTION: An interdigital neuroma is a common source of forefoot pain, and while second metatarsophalangeal joint instability is a less common entity, it can be a concomitant source of pain. The purpose of this study was to evaluate the long-term clinical course and surgical outcomes of the treatment of these concomitant problems.

METHODS: 121 consecutive patients (131 feet and 136 neuromas) were evaluated and treated for a symptomatic interdigital neuroma from 1981 to 1997. Of these, 24 patients (20%) had a concurrent interdigital neuroma (IDN) and second metatarsophalangeal (MTP) capsular instability that underwent surgical treatment. At the final follow-up examination, 20 patients (21 feet) were evaluated by an independent orthopaedic surgeon with a standardized clinical and radiographic examination, patient self-assessment and outcome measures.

RESULTS: Overall, there were 18 females and two males (21 feet) treated with an average age of 54 years at the time of surgery that returned for examination and follow-up at an average of 80 months (48 to 108 months) following surgery. Seventeen patients (85%) rated their result as good or excellent and three as fair. Six patients had mild continued symptoms referable to the second toe and none to the neuroma. Simultaneous neuroma excision and second MTP stabilization was performed in 15 cases and in six cases a staged repair was performed. The mean visual analog pain score was 1.4 (0=no pain, 10=severe pain) and mean MHAQ score was 1.13 (1-1.625) with activity modification stemming from hip, back and knee complaints.

CONCLUSION: With careful patient selection and preoperative assessment, resection of an interdigital neuroma and stabilization of second metatarsophalangeal joint instability resulted in a high percentage of successful results at greater than four years following the procedure. Objective results were comparable to previous reports on the surgical treatment of isolated interdigital neuroma and crossover second toe reconstruction. Subjective patient satisfaction was high but both subjective and objective results were lower in patients with persistent symptoms of MTP instability.