Proximal Tibial Cortex Transverse Distraction Facilitating Healing and Limb Salvage in Severe and Recalcitrant Diabetic Foot Ulcers
Authors: Chen Yan , Kuang Xiaocong , Zhou Jia , Zhen Puxiang , Zeng Zisan , Lin Zhenxun , Gao Wei , He Lihuan , Ding Yi , Liu Guangwei , Qiu Shaohua , Qin An , Lu William , Lao Shan , Zhao Jinmin , Hua Qikai 
Published: December 2019

Abstract

Background
The management of severe and recalcitrant diabetic foot ulcers is challenging. Distraction osteogenesis is accompanied by vascularization and regeneration of the surrounding tissues. Longitudinal distraction of the proximal tibia stimulates increased and prolonged blood flow to the distal tibia. However, the effects of transverse distraction of the proximal tibia cortex on severe and recalcitrant diabetic foot ulcers are largely unknown.

Questions/purposes
(1) Does tibial cortex transverse distraction increase healing and decrease major amputation and recurrence of severe and recalcitrant diabetic foot ulcers compared with routine management (which generally included débridement, revascularization, negative pressure wound therapy, local or free flaps, or skin grafts as indicated)? (2) Does neovascularization and perfusion increase at the foot after the procedure? (3) What are the complications of tibial cortex transverse distraction in patients with severe and recalcitrant diabetic foot ulcers?

Methods
Between July 2014 and March 2017, we treated 136 patients with diabetes mellitus and University of Texas Grade 2B to 3D ulcers (wound penetrating to the tendon, capsule, bone, or joint with infection and/or ischemia). The patients had failed to respond to treatment for at least 6 months, and their ulcers had a mean ± SD area of 44 cm2 ± 10 cm2. All 136 patients underwent tibial cortex transverse distraction (partial corticotomy of the upper tibia, which was in normal condition, followed by 4 weeks of transverse distraction medially then laterally). We compared these patients with the last 137 consecutive patients we treated with standard surgical treatment, consisting of débridement, revascularization, local or free flap or skin equivalent, or graft reconstruction along with negative-pressure wound therapy between May 2011 and June 2013; there was a 1-year period during which both treatments were in use, and we did not include patients whose procedures were performed during this time in either group. Patients in both groups received standard off-loading and wound care. The patients lost to follow-up by 2 years (0.7% of the treatment group [one of 137] and 1.4% of the control group [two of 139]; p = 0.57) were excluded. The patients in the treatment and control groups had a mean age of 61 years and 60 years, respectively, and they were predominantly men in both groups (70% [95 of 136] versus 64% [88 of 137]; p = 0.32). There were no differences with respect to parameters associated with the likelihood of ulcer healing, such as diabetes and ulcer duration, ulcer grades and area, smoking, and arterial status. We compared the groups with respect to ulcer healing (complete epithelialization without discharge, maintained for at least 2 weeks, which was determined by an assessor not involved with clinical care) in a 2-year follow-up, the proportion of ulcers that healed by 6 months, major amputation, recurrence, and complications in the 2-year follow-up. Foot arterial status and perfusion were assessed in the tibial cortex transverse distraction group using CT angiography and perfusion imaging.

Results
The tibial cortex transverse distraction group had a higher proportion of ulcers that healed in the 2-year follow-up than the control group (96% [131 of 136] versus 68% [98 of 137]; odds ratio 10.40 [95% confidence interval 3.96 to 27.43]; p < 0.001). By 6 months, a higher proportion of ulcers healed in the tibia cortex transverse distraction group than the control group (93% [126 of 136] versus 41% [56 of 137]; OR 18.2 [95% CI 8.80 to 37.76]; p < 0.001). Lower proportions of patients in the tibia cortex transverse distraction group underwent major amputation (2.9% [four of 136] versus 23% [31 of 137], OR 0.10 [95% CI 0.04 to 0.30]; p < 0.001) or had recurrences 2.9% (4 of 136) versus 17% (23 of 137), OR 0.20 [95% CI 0.05 to 0.45]; p < 0.001) than the control group in 2-year follow-up. In the feet of the patients in the tibial cortex transverse distraction group, there was a higher density of small vessels (19 ± 2.1/mm2 versus 9 ± 1.9/mm2; mean difference 10/mm2; p = 0.010), higher blood flow (24 ± 5 mL/100 g/min versus 8 ± 2.4 mL/100 g/min, mean difference 16 mL/100 g/min; p = 0.004) and blood volume (2.5 ± 0.29 mL/100 g versus 1.3 ± 0.33 mL/100 g, mean difference 1.2 mL/100 g; p = 0.03) 12 weeks postoperatively than preoperatively. Complications included closed fractures at the corticotomy site (in 1.5% of patients; two of 136), which were treated with closed reduction and healed, as well as pin-site infections (in 2.2% of patients; three of 136), which were treated with dressing changes and they resolved without osteomyelitis.

Conclusions
Proximal tibial cortex transverse distraction substantially facilitated healing and limb salvage and decreased the recurrence of severe and recalcitrant diabetic foot ulcers. The surgical techniques were relatively straightforward although the treatment was unorthodox, and the complications were few and minor. These findings suggest that tibial cortex transverse distraction is an effective procedure to treat severe and recalcitrant diabetic foot ulcers compared with standard surgical therapy. Randomized controlled trials are required to confirm these findings.

Level of Evidence
Level II, therapeutic study.