The treatment of femoral neck fractures: results using cephalocervical screws with sliding mechanism.

Background: A new device for the treatment of femoral neck fractures that uses 2 cephalocervical screws in a sliding mechanism allowing linear intraoperative and postoperative compression has been developed. The purpose of this retrospective study was to determine the results using this device for the treatment of stable and unstable femoral neck fractures.

Methods: Between November 2007 and November 2011, 61 consecutive skeletally mature patients with femoral neck fractures were treated with a new cephalocervical screw (Dual SC screw; KISCO DIR Co., Ltd., Kobe). All contactable patients were followed up for a minimum of 16 weeks postoperatively (range 16-123 weeks). Clinical and radiographic examinations were performed at the final evaluation. Healing and return to activities of daily living were used to evaluate outcomes.

Results: There were 51 women and 10 men with a mean age of 80.8 years (range, 41-99). The average of surgical time was 33.1 min (21-66 min). One patient died, one was too infirm for follow-up, and eleven could not be located, leaving 48 patients available for final evaluation (78.7%). The overall incidence of nonunion was 10.4%. Fracture nonunion was less common for undisplaced fractures than for displaced fractures (1 of 21 [4.8%] vs. 4 of 27 [14.8%]). The mean amount of collapse of the neck was 5.45 mm (3.92 mm in undisplaced and 6.64 mm in displaced). Radiographic analysis at final evaluation revealed no implant failures. 62.5% of the patients recovered their prefracture status.

Conclusion: The Dual SC screw device appears to be a reliable implant for the treatment of femoral neck fractures. Its design contributes to overcome the implant failures such as a medial migration, cut-out, or back-out; besides, the union rate of this implant was considered superior to that of existing systems. If the early shortening of the neck occurs after this surgery, the surgeons should be considered to keep them partially weight bearing or choose a replacement procedure for such patients.