Purpose: To present our clinical experience of intramedullary nail application during the consolidation phase after bone lengthening or bone transport.

Material and method: Thirty patients (33 cases) with secondary intramedullary nailing during consolidation phase after callus distraction with an external devise (Ilizarov frame or unilateral system) were evaluated. Docking site nonunion (17 patients), angular deformity or fracture of the lengthened area (8 patients) or intolerance of the external device (5 patients), in combination or not with a delayed distracted callus maturation, were the main reasons for this replacement.

Results: Average follow-up time was 4 (2–12 years). Average external fixation index was 40 days/cm of distraction. Intramedullary infection afterwards the placement of the nail was presented in one case (3,03%), and slight callus length loss in 5 cases (15,2%). Failure of union at the docking site with nail breakage was happened in 1 case (3,03%). In the other patients, ossification was achieved in the lengthened callus area as well as at the docking site, in an average time of 5,9 months from the moment of the nail insertion. All the patients were satisfied after the abstraction of the external devise, while their joint mobility and functionalism were improved rapidly.

Conclusions: The use of intramedullary nailing during consolidation phase after callus distraction, is a treatment option for delayed callus maturation or docking site nonunion, reducing the prolonged use of the external fixator.

We evaluate the effectiveness of external fixation exchange by intramedullary nailing during consolidation phase following callus distraction phase. In 12 skeletally mature female sheep, equally divided in two groups (group A and group B), we performed tibial shaft osteotomy and 2cm gradually callus distraction using Ilizarov external fixator in a 0.5mm/12h rate. In group A, immediately after lengthening completion, Ilizarov fixator was removed, and static unreamed intramedullary nail was inserted under fluoroscopic guidance. In group B (control group), Ilizarov frame remained (according to the usual technique) during consolidation phase. Callus maturity was studied in both groups, in specific time intervals, with plain x-rays, ultrasonograms, triplex and digital subscription angiograms. All animals were sacrificed 70 days after osteotomy and bone specimens including callus, were evaluated with MRI, DEXA and histopathologic examination.

In group A, all animals successfully tolerated intramedullary nailing, keeping limp alignment. All but one formatted a mature callus and kept callus length before being sacrificed. One sheep had a delayed formation of the callus and 0.5cm loss of callus length, because of failed insertion of distal locking screw in the nail. In group B, four of six formatted mature callus, two had axis disorder, three superficial pin-track infections and one deep infection in the same time.

We conclude that replacement of Ilizarov device by static unreamed intramedullary nail during callus consolidation phase decreases the total duration of external fixation, limits articular stiffness, pin-track infections and axial deformities, and provides protection against refracture. Our results suggest that there is no considerable difference between callus formations in the two groups.