[Torsional abnormalities and length discrepancies after intramedullary nailing for femoral and tibial diaphyseal fracture. Computerized tomography evaluation of 189 fractures].

Purpose Of The Study: We retrospectively determined by computed tomography torsionnal abnormalities and length discrepancies after diaphyseal tibial and femoral fractures treated by intramedullary nailing.

Material: Eighty femoral fractures and 89 tibial fractures were evaluated after healing. All these patients were treated by Grosse-Kempf intramedullary locked nail. AO classification was used: there were 16 type A, 32 type B and 32 type C, femoral fractures. Tibial fractures were 48 type A, 29 type B, and 12 type C. Reaming was systematic, 90 per cent of the nailing were static.

Methods: We measured comparatively length and torsion of tibias and femurs after bone healing and tried to find statistical correlation between clinical, epidemiological, anatomical factors and CT measurements.

Results: For the femur the mean difference in torsion was 9.9 degrees (max. -21 degrees min. +45 degrees) 52.5 per cent had the same measurements in intact and fractured side. For tibias the mean torsionnal value was 6.84 degrees. Seventy three per cent of patients had the same torsion in intact and fractured side. The mean femoral length discrepancy was 6.3 mm (max. -25 mm min. +19 mm) and 4.1 mm (max. -19, min. 20 mm) for the tibia. There were no statistical correlation.

Discussion: Even though there is no clinical sign after torsionnal abnormalities in our patients, hip, knee or ankle arthrosis is possible after nailed shaft fracture. A long term follow-up is necessary. A prospective study will be necessary in order to assess the exact frequency of these malalignements.