Dysplasia of distraction osteogenesis of the tibia bone transport: radiographic classification, and management protocols / 中华骨科杂志

ABSTRACT

Objective:To study the X-ray manifestations of distraction osteogenesis in tibial bone transfer, put for-ward the classification and formulate the standard treatment protocols.Methods:Data of 42 cases among 321 cases with dysplasia of distraction osteogenesis who had tibial bone transfer from January 2012 to December 2018 were retrospectively analyzed. There were 27 males and 15 females aged from 4-65 years old, with an average of 33.1 years. The dysplasia sites were 26 cases of proximal tibia, 3 cases of tibial shaft and 13 cases of distal tibia. The length of tibial defect ranged from 3.5 cm to 21.7 cm, with an average of 6.7 cm. The main management protocol included systemic assessment, local assessment, fixator adjusting stimulation and surgical intervention. The fixator adjusting stimulation included transport slowing, transport stopping, transport backing, and accordion techniques. The main surgical intervention was second site osteotomy and bone grafting. According to the X-films, the dysplasia of the tibia transport can be divided into four types longitudinal defect; transverse defect; insect erosion defect; full-length defect. External fixation index (EFI) was used to evaluate the healing and mineralization of distraction osteogenesis. The limb function was evaluated by Paley method.Results:All 42 cases were followed up for 33.71 ± 11.7 months (range, 24-72 months). The types of dysplasia were as follows 25 cases (59.5%) of longitudinal defects, 8 cases (19.0%) of transverse defect, 2 cases (4.8%) of insect erosion defect, and 7 cases (16.7%) of full-length defects. After the treatment, except for 2 cases of amputation, all the dysplasia healed and the patients recovered limb walking. External fixation index of 40 cases was 1.55-2.83 months/cm, with an average of 1.76 months/cm. According to Paley evaluation method, 27 cases were excellent, 10 cases good, 1 case fair, and 2 cases poor, thus the excellent and good rate was 92.5% (37/40). The complications after treatment included nail tract infection (3 cases), axial displacement of transferred segment (4 cases), clubfoot (2 cases), and amputation (2 cases). The total incidence of complications was 26.2% (11/42), which was symptomatically treated.Conclusion:The X-film manifestations of dysplasia at the osteotomy site in tibial bone transport can be divided into four types longitudinal defect, transverse defect, insect erosion defect, and full-length defect. The different types were treated by general and local evaluation, frame adjustment stimulation and surgical intervention. The remedial results of the dysplasia were excellent.