Review Question - QID 3238

Forefoot ulcers are exacerbated by a fixed plantarflexion contracture secondary to either a tight Achilles or gastrocnemius tendon. The Silfverskiold test differentiates isolated contractures of the gastrocnemius from the gastrocsoleus complex. The forefoot is inverted and the hind foot is positioned in subtalar neutral to lock the transverse tarsal joints. The knee is first flexed with ankle dorsiflexion and then compared to passive motion with the knee extended. Illustration A shows a positive test with equinus contracture in the presence of palpable pulses and a plantarflexion contracture.

Wagner grade 1 and 2 ulcers (abscence of osteomyelitis) should be treated with total contact casting AND gastrocnemius recession when indicated to decrease the risk of ulcer recurrence. An MRI scan with contrast would be helpful if there was concern for infection. Ankle-brachial index and transcutaneous oxygen measurements should be performed in the absence of palpable pulses. HgbA1C levels are useful in guiding the chronic management of diabetes and should be optimized. However, it is less useful in the acute management of a plantar ulcer.

Lin et al looked at 93 neuropathic diabetes mellitus patients with foot ulcers who underwent a total contact cast protocol. Fifteen of the patients showed delayed ulcer healing and all were noted to have an ankle equinus deformity and limited joint motion. This group was treated with percutaneous tendo-Achilles lengthening, and all but one ulcer went on to heal.

Mueller et al randomized 64 subjects into two treatment groups, immobilization in a total-contact cast alone or combined with percutaneous Achilles tendon lengthening. All ulcers healed in the Achilles tendon lengthening group, and the risk for ulcer recurrence was 75% less at seven months and 52% less at two years than the risk of recurrence in the total-contact cast alone group.