Monofocal bone transport technique for bone defects greater than 5 cm in tibia: our experience in a case series of 24 patients.

BACKGROUND: As the tibial bone defect increases in size, the problems in treatment also increase. The treatment may be problematic but different treatment approaches can be used. Among these approaches, distraction osteogenesis is a method an orthopedic surgeon with limited conditions can use although it has a longer treatment period. In our case series, we evaluated current treatment approaches.

METHOD: Retrospective study based on patient records and radiographs. We evaluated our cases with tibial bone defects Type B and greater than 5 cm. Twenty four cases were operated between 1995 and 2013. Clinical follow-up consisted of physical examination, review of radiographs, and Association for the Study of the Method of Ilizarov (ASAMI) scoring system of bone and functional results.

RESULTS: The defects had an average lenght of 7.01 cm (SD:2.88) (range, 5-18). The mean follow-up time from removal of the apparatus to the time of the last clinic visit averaged 74.08 ±24.17 months (range: 39-122). The Ilizarov frame was placed for transport and until bone was solid, average of 275.5 ± 70.6 days (range: 190-437 days). The mean external fixator time (EFT) was 350.91 ± 89.22 days (range: 261-627 days). The mean external fixator index (EFI) was 52 days/cm (range: 34.8-62.8 days/cm). Bone union was obtained in 23/24 (95.8%) patients. Seven patients suffered from stiffness (2 knee, 5 ankle) from which 3 patients developed equinus deformity and required tenoplasty (Achilles tendon lengthening at the time of frame removal. After reaching docking site, 5 patients needed intramedullary nailing to speed up union. Twelve (50%) cases had excellent radiological results, 8 (33%) cases had good, 2 (8%) cases fair and 2 (8%) cases had poor results. Regarding the functional ASAMI scoring system 14 (58%) cases had excellent, 9 (38%) cases had good and one case (4%) had fair result.

CONCLUSION: According to our experience, the Ilizarov bone transport technique remains a reliable method to repair bone defects. However, the treatment time is lengthy with a considerable risk of complications. We found closed intramedullary nailing as an effective and easy solution for cases without pin tract infections to manage the nonunion problem of the docking site and this option should be considered where the surgeon envisages difficulties of healing or the patient has lost patience with the frame. Careful selection of case and patient profile can optimize the outcomes.