Schwannomas are benign, encapsulated soft-tissue tumors that rarely present to the foot and ankle. These tumors are usually asymptomatic unless an increase in size or disruption of the nerve causes pain. We report a case of a painful mass along the lateral plantar nerve near the fourth metatarsal base that was surgically excised and confirmed as a benign schwannoma by means of histopathologic analysis. At the final follow-up of over 2 years, the patient reported no pain, neurologic deficits, or signs of recurrence. This case demonstrates an unusual location of a schwannoma arising from the lateral plantar nerve.
Background: Recurrent ulceration is a common problem after partial first-ray amputations. Loss of the first metatarsophalangeal joint contributes to altered biomechanics and increased pressure on the foot. This may increase risk of adjacent ulcerations and additional amputations. Preserving first-ray length maintains the metatarsal parabola and limits transfer lesions, but few data support this. We aimed to evaluate the incidence of ulceration after partial first-ray amputations and to assess the association between metatarsal protrusion distance and recurrent ulceration.
Methods: Thirty-two consecutive patients underwent unilateral partial first-ray amputation at various levels along the first metatarsal, and the metatarsal protrusion distance was measured after surgery. Incidence of ulceration was evaluated on the ipsilateral foot. We hypothesized that patients with a longer first metatarsal were less likely to ulcerate again on the ipsilateral foot.
Results: Fourteen patients (43.8%) ulcerated again after partial first-ray amputation. Mean time to ulceration was 104 days. Active smoking status was associated with increased risk of another ulceration (P = .02), and chronic kidney disease was associated with a decreased risk of recurrent ulceration (P = .03). The average metatarsal protrusion distance for patients who ulcerated again after surgery was 36.1 mm versus 25.9 mm for patients who did not (P = .04). Logistic regression analysis of the receiver operating characteristic curve demonstrated an ideal cutoff length for recurrent ulceration of 37 mm (area under the curve = 0.7381). Patients with a protrusion distance greater than 37 mm were nine times as likely to ulcerate again (95% CI, 1.7–47.0).
Conclusions: Partial first-ray amputations can be a good initial salvage procedure to clear infection and prolong bipedal ambulatory status. Unfortunately, these patients are prone to recurrent ulceration. Significant loss of first metatarsal length is a poor prognostic indicator for recurrent ulceration.
Despite advancements in the treatment of diabetic patients with “at-risk” limbs, minor and major amputations remain commonplace. The diabetic population is especially prone to surgical complications from lower extremity amputation because of comorbidities such as renal disease, hypertension, hyperlipidemia, microvascular and macrovascular disease, and peripheral neuropathy. Complication occurrence may result in increases in hospital stay duration, unplanned readmission rate, mortality rate, number of operations, and incidence of infection. Skin flap necrosis and wound healing delay secondary to inadequate perfusion of soft tissues continues to result in significant morbidity, mortality, and cost to individuals and the health-care system. Intraoperative indocyanine green fluorescent angiography for the assessment of tissue perfusion may be used to assess tissue perfusion in this patient population to minimize complications associated with amputations. This technology provides real-time functional assessment of the macrovascular and microvascular systems in addition to arterial and venous flow to and from the flap soft tissues. This case study explores the use of indocyanine green fluorescent angiography for the treatment of a diabetic patient with a large dorsal and plantar soft-tissue deficit and need for transmetatarsal amputation with nontraditional rotational flap coverage. The authors theorize that the use of indocyanine green may decrease postoperative complications and cost to the health-care system through fewer readmissions and fewer procedures.