SLR - May 2015 - Brian Rex

Surgical Treatment of Cavus Foot in Charcot-Marie-Tooth Disease: A Review of Twenty-four Cases: AAOS Exhibit Selection

Reference: Faldini C, Traina F, Nanni M, Mazzotti A, Calamelli C, Fabbri D, Pungetti C, Giannini S. Surgical Treatment of Cavus Foot in Charcot-Marie-Tooth Disease: A Review of Twenty-four Cases: AAOS Exhibit Selection. J Bone Joint Surg Am. 2015 Mar 18;97 (6):e30.

Scientific Literature Review

Reviewed By: Brian Rex, DPM
Residency Program: Botsford General Hospital

Podiatric Relevance: Symptomatic cavus foot is seen in the podiatric clinic and the most common associated diagnosis is Charcot-Marie-Tooth. It is believed that the cavus foot is caused by muscle imbalance involving the intrinsic and extrinsic muscles. The goal of surgical treatment is to correct the deformity to obtain a plantigrade foot. In the presence of a flexible deformity and the absence of degenerative arthritis, preserving as much as possible of the overall range of motion of the foot and ankle is advisable. The goal of this study was to determine if this could be achieved with a plantar fasciotomy, a midtarsal osteotomy, an extensor hallucis longus tendon transfer to the first metatarsal (Jones procedure), and a dorsiflexion osteotomy of the first metatarsal.

Methods: The study included twenty-four cavus feet in twelve patients with Charcot-Marie-Tooth disease. Clinical evaluation was summarized with the Maryland Foot Score. The radiographic measurements used to evaluate the correction were calcaneal pitch, Meary’s angle, Hibb angle, and the absence of degenerative joint changes. Inclusion criteria consisted of patients who had a flexible deformity determined by a reducible varus heel in the Coleman-Andreasi test, and did not have degenerative joint arthritis. Surgical treatment consisted of a plantar fasciotomy, a midtarsal osteotomy, an extensor hallucis longus tendon transfer to the first metatarsal (Jones procedure), and a dorsiflexion osteotomy of the first metatarsal. Mean follow-up was six years with a range of two to thirteen years.

Results: The mean Maryland Foot Score improved from 72 preoperatively to 86 postoperatively. The postoperative result was rated as excellent in twelve feet (50 percent), good in ten (42 percent), and fair in two (8 percent). Mean calcaneal pitch was 34 preoperatively and 24 at the time of the latest follow-up. The mean Hibb angle was improved from 121 preoperatively to 136 postoperatively. The mean Meary’s angle was 25 preoperatively and two postoperatively.

Conclusions: The authors concluded that a plantar fasciotomy, a midtarsal osteotomy, a Jones procedure, and a dorsiflexion osteotomy of the first metatarsal yielded adequate correction of flexible cavus feet in patients with Charcot-Marie-Tooth disease in the absence of fixed hindfoot deformity. However, they admit that the improvement in the outcome score was modest and may be attributable to the lack of motor balance. I conclude that the procedures as performed by the authors provided radiologic correction but the surgeon must help the patient have a realistic view of the intended outcomes. Also, attention must be given to help improve motor balance post-operatively.

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