The stability score of the intramedullary nailed intertrochanteric fractures: stability of nailed fracture and postoperative patient mobilization

Abstract

Background: Intertrochanteric fractures of the femur are the most common type of fracture, and are an increasing occurrence due to the aging of the population. The objectives of our study are to predict the fate of intertrochanteric fractures treated with intramedullary hip nails by assessing the postoperative fracture stability utilizing the newly developed scoring system, and to help rehabilitate these patients.

Methods: Eighty-two patients with intertrochanteric fractures that were treated with intramedullary hip nails between December, 2004 and January, 2011 were subjected to this study. The patients who could be followed for a minimum of one year postoperatively were enrolled. The immediate postoperative conditions were determined by radiograms: reduction status (3 parameters/4 points: contact accuracy of posteromedial cortex, severity of angulation, and distraction), fixation status (3 parameters/3 points: tip-apex distance, location of tip of the lag screw, entry point of the intramedullary nail), and fracture type (1 parameter/1 point: stable or unstable type by the Kyle's classification). Postoperative reduction loss and fixation failure were checked by radiograms taken at a minimum 3 months postoperative.

Results: Reduction loss and fixation failure were observed in 14 consecutive patients (17%). The fixation failure rate was 100% (2 patients) in score 1, 60% (3 out of the 5 patients) in score 2, 39% (3 out of the 8 patients) in score 3, and 50% (4 out of the 8 patients) in score 4 groups. There were fixation failures only in 1 out of 13 patients with score 5, and in 1 out of 18 patients with score 6. There was no fixation failure in 17 patients with score 7 and 11 patients with score 8.

Conclusions: Maintenance of the fracture reduction by the stable fixation in the patient scores over 5 could be predicted by the postoperative radiograms.

Keywords: Fixation stability score; Fracture; Intertrochanteric; Intramedullary hip nail.

Fig. 1

The 6 parameters of the stability score system except fracture type parameter. Immediate postoperative anteroposterior (A) and lateral (B) radiographs show a total stability score of 7. (1) Bony contact of posteromedial cortex of trochanteric portion was obtained. There was no (2) angulation or (3) distraction. (4) Tip-to-apex distance was 22 mm. (5) Entry point of intramedullary nail was located at the tip of the greater trochanter and (6) the lag screw tip was located at the Cleveland 5.

Fig. 2

Fixation failure case 1. (A, B) Immediate postoperative radiographs at Kyle's type III fracture show a total stability score 1. Tip-to-apex distance 35 mm, superolateral location of the lag screw tip, lateral entry point, and varus angulation were noted with loss of posteromedial cortex contact. (C, D) After 1 month, cut-out of the lag screw through the femoral head and varus collapse were noticed.

Fig. 3

Fixation failure case 2. (A, B) Immediate postoperative radiographs at Kyle's type III fracture show a total stability score of 3. Valgus angulation and distraction were noted with loss of contact of posteromedial cortex. (C, D) After 10 months, the intramedullary nail was broken and the hip joint was treated with hemiarthroplasty.

Fig. 4

Fixation failure case 3. (A, B) Immediate postoperative radiographs at Kyle's type III fracture show a total stability score of 2. Tip-to-apex distance 45 mm, valgus angulation and anterior location of the lag screw tip are noted with loss of posteromedial cortex contact. (C, D) Postoperative 6 months radiographs show back-out of the sliding hip screw and cut-out of anti-rotational pin in the head with varus collapse.

Fig. 5

The failure rate on each stability score.