Proximal Femoral Shortening and Varus Collapse After Fixation of "Stable" Pertrochanteric Femur Fractures.

OBJECTIVES

To evaluate and compare femoral neck shortening and varus collapse in stable pertrochanteric femur fractures treated with sliding hip screws (SHSs) or cephalomedullary nails (CMNs).

DESIGN

Retrospective review.

SETTING

Academic medical center.

PATIENTS

A total of 290 patients were included in the study. The average age was 82 years, and most were women. All sustained low-energy pertrochanteric femur fractures (OTA/AO A1.1, 1.2, 1.3, 2.2) treated operatively with SHSs or CMNs. Minimum radiographic follow-up was 3 months, with an average of 28 (range 3-162) months.

INTERVENTION

CMN or SHS fixation.

MAIN OUTCOME MEASURES

Varus collapse of the femoral neck-shaft angle and proximal femoral shortening.

RESULTS

Both implants allowed some varus collapse. Univariate analysis demonstrated a significantly greater portion of patients with SHSs progressed to varus collapse >5 degrees (P = 0.02), mild horizontal shortening >5 mm (P < 0.01), and severe horizontal shortening >10 mm (P < 0.01). There was no statistical difference in vertical shortening (P = 0.3). There was no difference in implant failure (P = 0.5), with failure rates of 3% for cephalomedullary implants and 5% for SHS constructs.

CONCLUSIONS

The SHS group experienced greater varus collapse and horizontal shortening. There was no difference in overall implant failure. These findings suggest that the CMN is a superior construct for maintenance of reduction in stable pertrochanteric fractures, which may lead to improved functional outcomes as patients recover.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.