Session IV - Femur

Acute Lengthening of the Femur over an Intramedullary Nail

Carlos F. Sancineto, MD; Jorge D. Barla, MD; Ivan Rubel, MD; Guillermo Vasquez-Ferro, MD, Italian Hospital, Buenos Aires, Argentina

Introduction: Shortening of the femur is a common problem following fractures and their treatment. Several procedures have been described for regaining the original length. Slow distraction osteogenesis with external fixation devices either over an intramedullary nail or not has been the standard of treatment for this deformity. However, a small amount of shortening allows the surgeon to perform acute lengthening. The purpose of the study was to present our experience with a protocol for acute femoral distraction.

Material and Methods: Eighteen patients were included in this protocol from January 1998 to date. Six females and 4 males with an average age of 35 years have had at least one-year follow-up and are the subjects of this paper. The average shortening was 4.5 cm (range 3-6 cm). A butterfly osteotomy with a medial base was performed on the diaphysary-subtrochanteric region. A femoral distractor was applied to the lateral side of the femur. The osteotomy was checked for distraction up to 2 cm under a C arm and bone grafted with autologous iliac crest cancellous bone graft. A reamed antegrade femoral nail was then inserted and locked at one end of the nail. At this point, the patients were awakened from the anesthesia. The distraction was performed with the patient awake and alert, monitoring the neurological status for motor and sensitivity abnormalities. Skeletal traction complementary to femoral distractor was used in heavy patients.

Length was assessed on leg length films. When the desired lengthwas achieved, the patient was taken to surgery for completion of the nail interlocking and removal of the femoral distractor.

Results: Lengthening averaged 4.4 cm (range 3-6 cm). The distraction period averaged 7 days (3-12). All distractions healed within a 4-month period. Schanz pins were seen to bend in 6 cases at the end of the distraction. During distraction, one Schanz pin required repositioning. Pin tract minor infections were identified in 3 cases. All infections subsided with oral antibiotics, and no deep infections were detected. No nail or interlocking screw breakage was identified.

Discussion: Acute distraction of the long bones is a controversial issue. Lengthening of the femur over an intramedullary nail has an advantage over other techniques. It allows shorter latency, distraction and docking intervals because the interlocking screws control length, alignment and rotations. The use of butterfly osteotomies splits the distraction gap in halves, decreasing, we believe, the risk of nonunion reported for acute lengthening. Neurologic and vascular stretching during acute lengthening is problematic. In this study the neurological motor and sensitivity functions were monitored with the patient awake and alert, speeding or slowing the distraction rate according to the clinical examination.

Conclusion: Acute lengthening of the femur up to 6 cm with healing and correction of the deformity was possible in this series of patients following this protocol.