A load-sharing nail - cage construct may improve outcome after induced membrane technique for segmental tibial...

Induced membrane technique (IMT) is a well-established technique for treating segmental bone defects. Different variations of the technique have been described. Our objective was to evaluate radiological and functional outcome with IMT using a nail - graft filled titanium cage construct for segmental traumatic bone defects of the tibia.

26 adult patients with moderate (> 5 cm) or large (> 10 cm) segmental tibial defects after acute open fractures or implant related infected nonunions underwent the procedure. The technique involved 2 stages. After standard debridement +/- implant removal and application of an antibiotic loaded cement spacer in stage 1, the second stage included placement of an intramedullary nail across the defect and an impacted graft filled titanium mesh cage was used to reconstruct the bone defect. Radiographic evidence of bony union, time to painless un-assisted weight bearing, return to work and functional evaluation with lower extremity functional scale (LEFS) were assessed.

5/26 cases were excluded due to failure in controlling infection. 100% union rates were achieved in the remaining 21 patients. 2 patients (9.5%) required repeat bone grafting. The mean time to painless un-assisted painless weight bearing was 26 ± 9.2 days and the mean time to return to work was 45 ± 12.5 days. The mean LEFS at a mean follow up of 27 months was 67 ± 4.7.

Excellent union rates with good functional restoration can be achieved after IMT using the nail - cage construct for segmental tibial defects. Persistent infection is the biggest impediment for successful execution of the technique. Addition of a cage may also improve short-term functional outcome in terms of ability to weight bear and early return to work.