SLR - September 2019 - Disha Shah
Reference: Zachariah Pinter, BS, Christopher Odom, MD, Andrew McGee, BS, Kyle Paul, BS, Samuel Huntley, BS, John L. Johnson, BS, and Ashish Shah, MD. Morton’s Neuroma Excision. What Are We Really Doing? Which Retractor Is Superior? Foot & Ankle Specialist. 2019 June; 12(3), 272-277.Scientific Literature Review
Reviewed By: Disha Shah, DPM
Residency Program: Hoboken University Medical Center – Hoboken, NJ
Podiatric Relevance: Morton’s neuroma, common pathology of the forefoot is a neuropathy of the plantar digital nerve most typically arising as a chronic degenerative process. Treatment usually consists of conservative treatment such as changing shoe gear, padding, injections, etc. Surgical intervention is utilized if conservative management fails. Excision of morton’s neuroma can be performed via either a plantar or dorsal approach. The dorsal approach is simpler than plantar approach however, has complications like stump neuroma resulting in nerve entrapment. Current research indicates nerve to be resected 3 centimeters proximal to the deep transverse metatarsal ligament (DTML) to obtain adequate resection.
Methods: A level IV cadaveric study was performed with 12 fresh cadaver specimens each of which underwent dorsal approach to the interdigital nerve with proximal resection in second and third interspace. Primary purpose was to demonstrate how far proximally the nerve is actually resected using the existing guidelines. Secondary purpose to determine whether a significant difference exists between lamina spread of the gelpi retractor for optimal visualization. One senior foot and ankle surgeon performed all procedures. He made a 3 centimeter incision proximal to second and third webspaces, blunt dissection was then performed to gain access to DTML. Metatarsals were then spread using lamina spreader or gelpi retractor. The nerve was resected and length of the cut nerves were compared based on the retractor employed.
Results: Mean length of proximal resection in the second intermetatarsal space was 2.42 centimeters when using the lamina spreader and 1.93 centimeters when using the gelpi retractor. In the third intermetatarsal space, the mean length of proximal resection was 2.14 centimeters when using the lamina spread and 1.48 centimeters when using the gelpi retractor.
Conclusions: Results demonstrate that the lamina spreader rather than the gelpi retractor consistently provides the surgeon with better visualization of the interdigital nerve and allows for maximal proximal resection of the nerve. They demonstrated that the nerve could be transected 2.5 centimeters in the second intermetatarsal space and 2.15 centimeters in the third intermetatarsal space proximal to the deep transverse metatarsal ligament. Some limitations of this study include small sample size, cadaveric study. The length of the nerve was measured from the tip of the metatarsal head rather than the DTML as mentioned in published article.