Session II - Femur
Treatment of High-Energy Femoral Neck-Shaft Fractures
Introduction: A relative indication for retrograde nailing is felt to be ipsilateral femoral neck-shaft fractures. However, sometimes the femoral neck fracture may be found on a delayed basis, during or even after surgical stabilization of the shaft. Our purpose was to evaluate timing of diagnosis and the treatment options for femoral neck-shaft fractures and their outcomes.
Methods: A retrospective review of all femoral shaft fractures at eight level 1 trauma centers was completed. 2897 femoral shaft fractures were identified. There were 91 femoral neck-shaft combinations (3.1%) in 89 patients. The operative records, charts, and radiographs were reviewed for pertinent details including age, ISS, mechanism of injury, fracture data, use of preoperative CT, timing of discovery of femoral neck fracture, associated injuries, implants chosen, and union and complication rates.
Results: The average age of the cohort was 36 (range, 15-72) with 51 males and 38 females. The average ISS was 18 (range, 9-66) and 78 patients (88%) had associated injuries. 31 femoral shaft fractures were open (34%). A total of 67 femoral neck fractures in 65 patients were discovered before nailing (BN). Eleven fractures were discovered intraoperatively (IO), and 13 femoral neck fractures were found postoperatively (PO). Of the 11 IO discoveries, 6 patients had no preoperative CT and 5 had CT with no visible fracture. Of the 13 PO discoveries, 2 had no preoperative CT, 9 had preoperative CT with no visible fracture, and 2 had a missed fracture that was visible on preoperative CT. For all femoral shaft fractures, the missed diagnosis rate of a femoral neck fracture was 0.4%. Considering all PO discoveries, the missed diagnosis rate was 14%. Overall, eleven patients were lost to follow-up and there were 2 deaths in the 89 patients. The average follow-up was 17 months (range, 2-54). There were 9 cases of nonunion (NU)/malunion (MU) of the femoral neck and 4 NU of the shaft.
Six of the patients with neck MU/NU were known BN. Seven of the neck nonunions had additional surgeries (6 osteotomies and one total hip) and are healing or healed and 2 patients desired no further intervention. There were 4 femoral shaft nonunions (all retrograde nails) that have done well with dynamization or exchange nailing.
Conclusions: This study shows a lower rate of femoral shaft-neck combinations (3.1%) than previously reported. Our data also demonstrate interesting trends including the high rate of open shaft fractures (34%) and an increased incidence of associated injuries (88%) with shaft-neck combinations. With a 14% missed fracture rate, this supports the need for increased vigilance. It is difficult to determine if all PO discoveries could be attributed to treatment type (antegrade vs. retrograde nail). Preoperative CT scans did not demonstrate the diagnosis of femoral neck fracture in 19 patients (21%). Of the 11 PO discoveries who had a preoperative CT, the femoral neck fracture was missed in 81% of the patients. In our review, the value of the preoperative CT is questionable. To subject all patients with a femoral shaft fracture (without an injury already requiring a CT scan) to the expense and radiation exposure of a thin-cut CT scan is not a substitute for careful evaluation of the femoral neck during nailing and good quality anteroposterior and lateral radiographs after femoral shaft nailing. We found an overall 10% NU/MU rate in our neck-shaft fixation combinations. There was a 33% incidence of NU/MU when the femoral neck fracture was discovered in the postoperative period. Predictors of a NU/MU of the neck were OTA 31 B2/B3 fractures with comminuted, open shaft fractures (32 A3/B3) and a delay in diagnosis of the neck fracture. Six cases of NU/MU were treated with retrograde nails/CS for an 8% NU rate of this implant choice (P >0.05).There was no incidence of NU/MU when a retrograde nail/DHS was used (P >0.05). The femoral neck-shaft fracture remains problematic and an optimal treatment approach has yet to be determined.