Causes and management of bone nonunion at the docking sites after tibial bone transport

Abstract

Objective To explore the causes and management of bone nonunion at the docking sites after tibial bone transport.Methods From January 2006 to January 2012,tibial bone transport technique was used to treat 40 patients with tibial bone defect,infectious nonunion or osteomyelitis.They were 28 males and 12 females,aged from 16 to 62 years (average,29.0 years).Twenty-eight cases were open tibial fractures and 12 closed tibial fractures with postoperative infection.The bone defects of the 40 patients averaged 5.5 cm,ranging from 2 to 12 cm.The average time from injury to bone transport was 10.0 months.The alignment and transport speed were adjusted after operation.Weight-bearing was encouraged in the patients.Results The 40 patients were followed up for 16 to 36 months (average,22.0 months) postoperation.Spontaneous union of the docking sites was achieved in 19 cases but not in the other 21 cases (52.5％).Causes included sclerosis of the docking sites in 11 cases,insufficient contact between the docking sites in 2 cases,embedding of skin or hypodermis into the docking sites in 3 cases,obvious malposition of the docking sites in 3 cases,and secondary soft tissue deformity or osteoporosis following shortening in 2 cases.They were treated respectively with the accordion technique (8 cases),simple bone grafting (2 cases),internal and external fixation combined with bone grafting (8 cases) and open bone grafting (3 cases).Bone lengthening ranged from 2 to 12 cm (average,5.2 cm).External fixation index was from 1.4 month/cm to 2.3 month/cm (average,2.02 month/cm).According to Paley's evaluation criteria for infectious bone nonunion and osteomyelitis,12 cases were excellent,18 good,4 moderate and 6 poor,giving a good to excellent rate of 75.0％.Conclusions A great number of tibial defects can not achieve spontaneous union at the docking sites after tibial bone transport.Normal soft tissue balance and correction of the lower limb alignment should be dealt with simultaneously during the procedure.The patient should adhere to weight-bearing to improve the alignment and enhance bone quality after operation.In cases where spontaneous union has not been achieved,nonunion can be managed with suitable skills like accordion technique and bone grafting. Key words: Tibia; Ilizarov technique; Osteomyelitis; Fracture, ununited