What The Evidence Reveals About Midfoot Ulcers In Patients With Diabetes
A Closer Look At The Efficacy Of Exostectomy
One may utilize exostectomy to resect the osseous prominence of the plantar foot to minimize ulceration. This procedure works best in patients with a stable, inactive Charcot deformity. The surgeon can utilize a direct or indirect approach. An indirect approach involves making the surgical incision on the medial or lateral aspect of the foot above, and adjacent to the site of the ulceration. One would then use an osteotome or sagittal saw to resect the osseous prominence. The advantages of an indirect approach are avoidance of a plantar incision and a reduced risk of contamination as the approach is not through the ulceration.1 The surgeon would perform a direct approach through the ulceration or via excision of the ulceration, providing direct access to the bone to be resected beneath.
The difficulty with exostectomy lies in ensuring adequate bone resection to minimize the potential for recurrent ulceration while avoiding excessive resection, which could potentially lead to destabilization of the foot.1,8 There is currently no widely accepted protocol to quantify how much bone to resect. Wieman and colleagues describe a method in which one performs osseous resection with an attempt to “recreate” the arch of the foot.1 With this technique, the surgeon would do osseous resection in a curvilinear fashion, extending distally from the inferior aspect of the first metatarsal to the calcaneus proximally and approximately one-third superiorly into the arch of the foot. Reported complications following exostectomy are a non-healing wound, recurrent ulceration, wound dehiscence, instability necessitating conversion of the exostectomy to arthrodesis, skin/soft tissue infection, osteomyelitis and amputation.1,6,8-10
Wieman and coworkers reported on the results of exostectomy, using the resection technique described above, in 40 patients with 54 diabetic midfoot ulcers.1 The mean age was 60.2 ± 1.8 years. The mean duration of the ulceration was 212 ± 179 days. Surgeons used an indirect approach in all cases. The mean follow-up time was 38 ± 36 months. There were 29 (54 percent) amputations that occurred secondary to combined infection and peripheral vascular disease. The 25 remaining ulcerations took a mean of 129 ± 62 days to heal. There was one wound dehiscence and two recurrent ulcerations.
Brodsky and Rouse reported on 12 patients who all had an indirect approach for eight plantar medial ulcerations and four plantar lateral ulcerations.8 The average patient age was 56. The follow-up time was 25 months. Nine patients went on to successful healing of their ulcerations. Complications consisted of four cases of serous drainage, three cases of delayed healing and one recurrent wound. There were two deaths, both of which were unrelated to the foot. The one patient with a recurrent wound required a Symes amputation after the wound recurred following two exostectomy procedures. This patient previously had incision and drainage of a plantar foot abscess, and subsequent coverage with a split thickness skin graft (STSG). The authors felt the tenuous nature of the plantar skin due to the STSG was the etiology for the recurrent ulceration.
Myerson and colleagues reported on 12 patients who had an exostectomy.11 Eight of these patients were stable and ulcer-free 32 months after the procedure. Complications consisted of conversion to arthrodesis (three patients with two being secondary to instability) and one amputation secondary to infection at three months postoperatively.11