Purpose: Traffic accidents and high level falls are the principal causes of femur trauma. Fractures generally involve the shaft but the proximal or distal metaphyseal zones may also be involved. Skin opening, vascular injury or associated lesions in multiple injury patients are all reasons for emergency treatment with an external fixator.
Material and methods: We report a retrospective series of 23 cases who were treated with this technique between 1996 and 2000. There were 15 men and seven women, mean age 36 years (17–92) who were traffic accident victims in 17 cases. Fourteen had multiple injuries. The mean Index Severity Score was 28 points. Fractures were located in shaft in 16 cases, the proximal metaphysis in three, and in the supra and intercondylar zone in nine. The Chauchoix and Duparc classification was grade 2 in eight cases, and grade 3 in three cases. The fixation was installed with two or three pins in the lateral position; The knee was bridged in cases with an associated injury to the proximal tibia (floating knee) (two cases) or severe injury to the knee ligaments. Patients were reviewed clinically and radiographically. Bone healing was considered to be achieved when full weight bearing was possible without osteosynthesis contention.
Results: Twenty patients were reviewed. Mean follow-up was 20 months (7–42). Bone healing was achieved in 100% of the cases with a mean delay of 9.4 months (4–32). In three patients 13%) a complementary procedure (cancellous graft or bone marrow graft) was needed to achieve healing, the delay in these patients was 22 months compared with 7.5 months without secondary procedures. One patient developed a callus with a >
10° deviation of the AP view and five permanent flexion greater than 10°. Supra and intercondylar fractures healed at a mean 6.6 months in five cases with a deformed callus. The force moment related to excessive spread of the fixator pins (greater than 20 cm) was not a factor of poor final radiological outcome. Mean knee flexion was greater than 100° in only three cases. These amplitudes were not obtained until the fixator pins were removed. No releasing procedures were needed. Three mobilisations under general anaesthesia were needed.
Discussion: External fixation allows stable and dynamic osteosynthesis of femoral shaft fractures. It is indicated when centromedulary nailling is impossible or for patients with an excessively high risk of infection. The insertion of the pins must be rigorously control (perpendicular to the diaphysis, bicortical insertion, far enough apart). Supra and intracondylar fractures remain difficult to stabilise with external fixations and internal plate fixation may be discussed in grade 2 open fractures. These can give poor functional results despite rapid consolidation. An immediate corticocancellous graft may be indicated when metaphyseal comminution requires stabilisation, mainly on the medial aspect to avoid varisation.
Conclusion: External fixation is an interesting solution for safe fixation of open shaft fractures (grade 2 and 3) or fractures associated with vascular and nerve injury. It would be more indicated for shaft fractures than for supracondylar fractures which are difficult to stabilise, particularly in case of major comminution.
