[Ilizarov metatarsal bone lengthening in treatment of diabetic foot ulcer complicated with chronic osteomyelitis of metatarsal head].

OBJECTIVE: To explore the effectiveness of the first-stage debridement and Ilizarov metatarsal bone lengthening in treatment of diabetic foot ulcer complicated with chronic osteomyelitis of metatarsal head. METHODS: Between January 2015 and October 2018, 8 cases (9 feet, 11 sites) of diabetic foot ulcer complicated with chronic osteomyelitis of metatarsal head were treated by first-stage debridement and Ilizarov metatarsal bone lengthening. There were 3 males (4 feet, 5 sites) and 5 females (5 feet, 6 sites), with an average age of 57.5 years (range, 44-65 years). According to diabetic foot Wagner grade, 6 cases (7 feet) were grade 3 and 2 cases (2 feet) were grade 4. The chronic osteomyelitis located at left foot in 4 cases, right foot in 3 cases, and bilateral feet in 1 case. The duration of chronic osteomyelitis was 1-5 years (mean, 3.1 years). The chronic osteomyelitis site was the 1st metatarsal head in 3 feet, the 3rd metatarsal head in 1 foot, the 4th metatarsal head in 1 foot, and the 5th metatarsal head in 6 feet. Two patients had chronic osteomyelitis at 2 sites on 1 foot. The length of lengthened metatarsal bone, lengthening time, and the time of wearing external fixation frame were recorded, and the external fixation frame index was calculated. The healing conditions of foot ulcer and lengthening bone segment were observed, the healing time was recorded, and the healing index of lengthening bone was calculated. The ankle function was evaluated according to the American Orthopedic Foot and Ankle Society (AOFAS) score criteria. RESULTS: All patients were followed up 9-26 months with an average of 15.0 months. Except pin tract infection during the bone lengthening period, there was no complications such as skin necrosis and vascular or nerve injury occurred during treatment. The length of lengthened metatarsal bone was 12-35 mm with an average of 20.5 mm; the metatarsal bone lengthening time were 21-84 days with an average of 57.8 days. The average time of wearing external fixation frame was 14.6 weeks (range, 10.4-21.1 weeks) and the external fixation frame index was 54.3 days/cm (range, 42.9-59.2 days/cm). The ulcer wound healed with an average healing time of 30.5 days (range, 19-70 days) and no ulcer recurrence was observed during follow-up. Bone healing was obtained in all bone lengthening segments, and the average healing index was 42.5 days/cm (range, 37-51 days/cm). The average AOFAS score was 91.7 (range, 87-95); 5 feet were excellent and 4 feet were good. The excellent and good rate was 100%. CONCLUSION: The metatarsal bone lengthening under Ilizarov law of tension-stress after debridement can promote diabetic foot ulcers healing and reconstructing the length of metatarsal to retain the function of metatarsal load and avoid amputation. This is an effective method for the treatment of diabetic foot ulcer complicated with chronic osteomyelitis of metatarsal head.