Isolated Intermetatarsal Ligament Release as Primary Surgical Management for Morton’s Neuroma

Abstract

Category: Midfoot/Forefoot Introduction/Purpose: While the precise pathoetiology of Morton’s neuroma remains unclear, nerve inflammation as a result of chronic entrapment from the overlying intermetatarsal ligament (IML) may play a role. Traditional surgical management involved common digital nerve transection with neuroma excision, but this procedure risks unpredictable formation of a stump neuroma and potential worsening of symptoms. Accordingly, the senior author has over the past six years espoused isolated IML release and common digital nerve decompression in lieu of nerve transection or neuroma excision as an alternative treatment strategy. We hypothesized that IML release offers effective pain relief and high patient satisfaction level as a surgical treatment for recalcitrant Morton’s neuroma without the risk of stump neuroma formation or symptom exacerbation. Methods: Medical records for all consecutive patients treated surgically with isolated single interspace IML release for symptomatic and recalcitrant Morton’s neuroma over a four year period at a large academic medical center were examined. Any adult patient with clinically diagnosed Morton’s neuroma who had failed at least three months of conservative treatment and who then underwent single-webspace IML decompression were included. Any patient who had less than three months postoperative follow up, had undergone revisional neuroma surgery, or had undergone additional procedures at the time of the IML release were excluded. Overall patient satisfaction as well as pre- and post-operative Visual Analog Pain Scale (VAS) assessments were recorded for all patients. Results: Eleven patients underwent isolated, single interspace IML decompression for Morton’s neuroma over this time frame. One of these patients had a neuroma localized to the second web space and 10 were localized to the third web space. Average follow-up was 10.8± 9 (3-32) months (Table 1). VAS pain scores averaged 6.4 ± 1.9 (4-9) preoperatively and decreased to an average of 1.5 ± 1.6 (0-5) at final follow up (P = 0.003). All patients reported significant pain improvement and an overall satisfaction with the procedure (would undergo it again). No patients returned to the operating room, there were no postoperative infection nor worsening of pain, and no other complications were reported. Conclusion: Isolated single interspace IML release of chronically symptomatic Morton’s neuroma shows promising short-term results regarding pain relief and overall patient satisfaction, with few complications and no demonstrated risk of recurrent neuroma formation, permanent numbness, or postoperative symptom exacerbation. The authors’ collective experience with this approach has been positive enough over the past six years to result in the entire abandonment of the practice of neuroma excision in this patient population.