Purpose: External fixation has restricted indications in fractures of the femur, particularly in the distal portion. Between 1986 to December 2001 we used external fixation for 21 first-intention treatments of metaphyseal epiphyseal distal femur fractures. This retrospective study was designed to detail the contribution of this type of fixation.
Material and methods: The series included 14 men and six women (one bilateral case), mean age 33 years (range 17–83). All patients were victims of high-energy trauma. Twelve had multiple injuries (mean ISS 20) and 16 had multiple fractures including ten floating knees. According to the Gustilo classification, the 20 open injuries were one type 1, five type II, fourteen type III including two IIIC with rupture of the femoral artery. Three patients had burns or degloving injury of the thigh. An exclusive femoro-femur fixation was used with a dynamic axial fixator associated with complementary epiphyseal screws in eight cases. The AO classification ws six metaphyseal injuries (4 C2, 7C22 and 3 C23). Associated procedures included two vessel repairs, two rectus dorsi flaps, and four modifications of the fixator or new reduction.
Results: One patient died from mulitple injuries. Two required amputation for failed vascular repair and free flap. Eight patients achieved bone healing with the fixator alone including two who had an autologous graft. Mean time to healing was 10 months (5–14). One patient developed secondary fracture at eight months treated successfully with retrograde nailing. The knee had to be mobilised in four cases and arthrolysis was necessary in three. For ten cases, the external fixator was replaced voluntarily with centromedularly nailing (n=2, one supracondylar and one Grosse Kempf), or plate fixation (n=8) associated with autologous graft in four (three fibular transfers and one iliac graft). These two operative times were consecutive in seven cases and separated by a period of traction in three. The two nailings and the five plate fixations healed in a mean eight months (5–10). Three plate fixations failed: two aseptic nonunions (prosthesis revision and arthrodesis) and one suppuration currently under treatment. At minimum follow-up of 18 months, 15 patients had a known clinical result with bone healing achieved: mean active flexion was 81° (50–120°). Only one patient had deficient extension (10°). Nine patients had achieved anatomic alignment in both the frontal and sagittal planes; three presented recurvatum of 5–10° and three had a frontal deviation less than 10°.
Discussion: This experience illustrates the difficulty in correctly reducing femoral alignment while maintaining active knee mobility. This series points out the risk of infection in case of secondary osteosynthesis. External fixation should be reserved for exceptional indications: rupture of the vascular trunk, major cutaneous injury, or a temporary solution in the case of multiple injuries before rapid osteosynthesis to achieve a stable fixation.
