Which implant is better for treating reverse obliquity fractures of the proximal femur: a standard or long nail?

Abstract

Background: Reverse obliquity fractures of the proximal femur have biomechanical characteristics distinct from other intertrochanteric fractures and high implant failure rate when treated with sliding hip screws. Intramedullary hip nailing for these fractures reportedly has less potential for cut-out of the lag screw because of their loadbearing capacity when compared with extramedullary implants. However, it is unclear whether nail length influences healing.

Questions/purposes: We compared standard and long types of intramedullary hip nails in terms of (1) reoperation (fixation failure), (2) 1-year mortality rate, (3) function and mobility, and (4) union rate.

Methods: We conducted a pilot prospective randomized controlled trial comparing standard versus long (≥ 34 cm) intramedullary hip nails for reverse obliquity fractures of the proximal femur from January 2009 to December 2009. There were 15 patients with standard nails and 18 with long nails. Mean age was 79 years (range, 67-95 years). We determined 1-year mortality rates, reoperation rates, Parker-Palmer mobility and Harris hip scores, and radiographic findings (fracture union, blade cut-out, tip-apex distance, implant failure). Minimum followup was 12 months (mean, 14 months; range, 12-20 months).

Results: We found no difference in reoperation rates between groups. Two patients (both from the long-nail group) underwent revision surgery because of implant failure in one and deep infection in the other. There was no difference between the standard- and long-nail groups in mortality rate (17% versus 18%), Parker-Palmer mobility score (five versus six), Harris hip score (74 versus 79), union rate (100% in both groups), blade cut-out (zero versus one), and tip-apex distance (22 versus 24 mm).

Conclusions: Our preliminary data suggest reverse obliquity fractures of the trochanteric region of the femur can be treated with either standard or long intramedullary nails.

Fig. 1A–E

Images illustrate the case of a 74-year-old woman treated with a long PFN-A. Initial (A) AP and (B) lateral views show the left hip with a reverse obliquity fracture of the trochanteric region of the femur. (C) AP and (D) lateral views show the hip after fixation with a long PFN-A. (E) Perforation of the joint with the helical blade after 5 months is shown.

Fig 2A–E

Images illustrate the case of a 76-year-old-man treated with a standard PFN-A. Initial AP views of the (A) pelvis and (B) left hip with a reverse obliquity fracture of the proximal femur are shown. (C) An AP view shows the hip after fixation with a standard nail. (D) AP and (E) lateral views of the hip after 12 months show bony union.