Repair of tibial nonunions and bone defects with the Taylor Spatial Frame

Abstract

Objective: To investigate the outcomes of tibial nonunions and bone defects treated with the Taylor Spatial Frame (TSF) using the Ilizarov method.

Design: Retrospective.

Setting: Limb Lengthening and Deformity Service at an academic medical center.

Patients: Thirty-eight consecutive patients with 38 tibial nonunions were treated with the TSF. There were 23 patients with bone defects (average 5.9 cm) and 22 patients with leg-length discrepancy (LLD) (average 3.1 cm) resulting in an average longitudinal deficiency (sum of bone defect and LLD) of 6.5 cm in 31 patients (1-16). The average number of previous surgeries was 4 (0-20). At the time of surgery, 19 (50%) nonunions were diagnosed as infected.

Intervention: All patients underwent repair of the nonunion and application of a TSF. Patients with bone loss were additionally treated with lengthening. Infected nonunions were treated with 6 weeks of culture-specific antibiotics.

Main outcome measurements: Bony union, time in frame, eradication of infection, leg-length discrepancy, deformity, Short Form-36 (SF-36) scores, American Academy of Orthopaedic Surgeons (AAOS) lower-limb scores, and Association for the Study of the Method of Ilizarov (ASAMI) bone and functional results.

Results: Bony union was achieved after the initial treatment in 27 (71%) patients. The presence of bone infection correlated with initial failure and persistent nonunion (P=0.03). The 11 persistent nonunions were re-treated with TSF reapplication in 4, intramedullary rodding in 3, plate fixation in 2, and amputation in 2 patients. This resulted in final bony union in 36 (95%) patients. The average LLD was 1.8 cm (0-6.8) (SD 2). Alignment with deformity less than 5 degrees was achieved in 32 patients and alignment between 6 degrees and 10 degrees was achieved in 4 patients. Significant improvement of Short Form-36 (SF-36) scores was noted in physical role (P=0.03) and physical function (P=0.001). AAOS lower-limb module scores significantly improved from 56 to 82 (P<0.001). ASAMI bone and functional outcomes were excellent or good in 36 and 34 patients, respectively. The number of previous surgeries correlated inversely with the ASAMI bone (P=0.003) and functional (P=0.001) scores.

Conclusions: One can comprehensively approach tibial nonunions with the TSF. This is particularly useful in the setting of stiff hypertrophic nonunion, infection, bone loss, LLD, and poor soft-tissue envelope. Infected nonunions have a higher risk of failure than noninfected cases. Treatment after fewer failed surgeries will lead to a better outcome. Internal fixation can be used to salvage initial failures.