What A New Study Reveals About Tendon Lengthening For Diabetic Plantar Foot Ulcers
Comparing Results And Complication Rates With Those From Other Studies
The strength of this study is the larger number of patients and longer follow-up than prior studies on tendon lengthening for foot ulcers from diabetes and other causes of neuropathy.2-15 The main weaknesses are the retrospective chart review and telephone follow-up of patients.
An analysis of control groups of randomized studies revealed that “good” wound care healed only 31 percent (142/458) of diabetic foot ulcers in five months.18 Total contact casting (TCC) healed an average of 80 percent of diabetic foot ulcers.19 The present study results for tendon lengthening demonstrated a 98 percent healing rate (98/100). These non-operative approaches appear to heal fewer ulcers than tendon lengthening.
A comparison of complications is challenging because of variable lengths of follow-up and variable reporting of complications in the literature. Guyton reported that 31 percent (22/70) of patients with TCC had developed new ulcers with a short term follow-up.20 Mueller reported an 81 percent (21/26) recurrence rate within two years after patients healed with TCC.7 There were no incision problems in the present study and only one recurrence with a new plantar heel ulcer and an 11 percent (11/98) recurrence rate at 38 months follow-up. The TCC seems to have more initial complications and a much higher recurrence rate than tendon lengthening. Dayer and Assal agree that tendon lengthening, rather than TCC, should become the “gold standard” treatment for plantar forefoot ulcers if additional studies have similar results.14
In my study, the rates of plantar heel ulceration were 3 percent (1/40) for metatarsal head ulcers and 1 percent (1/75) for all ulcers. These rates are much lower than the 15 percent rates (11/75) reported by Holstein and colleagues.9 These lower rates are probably explained by the low rate of over-correction of equinus from gastocnemius-soleus recession in comparison to the triple-cut Achilles tendon lengthening.8,12
Weiman and colleagues performed metatarsal head resection for 202 metatarsal ulcers in 98 patients with a mean 35-month follow-up. Death occurred in 28 percent (27/98) of patients and 13 percent (13/98) had major amputations. Eighty-eight percent (142/162) of the remaining ulcers healed. Wound infection occurred in 8 percent (17/202) of the ulcers. Transfer ulcers occurred in 72 percent (117/162) of ulcers in 54 percent (53/98) of patients.21 Their complication rates were higher than tendon lengthening.
Using the same method of reporting complications in my study, I found that out of the 40 patients with 44 metatarsal ulcers, 10 percent (4/40) died and 3 percent (1/40) had a major amputation for gangrene. Accordingly, there were 35 patients remaining who had 38 months follow-up. Ninety-eight percent (43/44) of the ulcers healed. There was a 16 percent (7/43) recurrence rate but these ulcers healed again with repeat tendon lengthening. Accordingly, 94 percent (33/35) of the remaining patients’ forefeet healed at 38 months follow-up. There were no wound infections and a 5 percent (11/44) incidence of transfer ulcers in 40 patients. These forefoot transfer ulcers all healed after additional tendon lengthening.