Sub- or intertrochanteric fracture following screw fixation of an intracapsular proximal femoral fracture: true complication or technical error?
OBJECTIVE
To review, retrospectively, the possible causes of sub- or intertrochanteric fractures after screw fixation of intracapsular fractures of the proximal femur.


METHODS
Eighty-four patients with an intracapsular fracture of proximal femur were operated between 1995 and 1998 by using three cannulated 6.25 mm screws. The screws were inserted in a triangular configuration, one screw in the upper part of the femoral neck and two screws in the inferior part. Between 1999 and 2001, we use two screws proximally and one screw distally.


RESULTS
In the first series, two patients died within one week after operation. Sixty-four fractures healed without problems. Four patients developed an atrophic non-union; avascular necrosis of the femoral head was found in 11 patients. Three patients (3.6%) suffered a sub- and/or intertrochanteric fracture after a mean postoperative time of 30 days, in one case without obvious trauma. In all three cases surgical revision was necessary. Between 1999 and 2001 we did not observe any fracture after screwing.


CONCLUSIONS
Two screws in the inferior part of the femoral neck create a stress riser in the subtrochanteric region, potentially inducing a fracture in the weakened bone. For internal fixation for proximal intracapsular femoral fracture only one screw must be inserted in the inferior part of neck.
Department of Traumatology, University Hospital, Lausanne, Switzerland.
St
S
Pelet
P F
PF
Leyvraz
R
R
Garofalo
O
O
Borens
E
E
Mouhsine
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001863:Bone Screws; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000601:surgery; D005593:Fracture Fixation, Internal / Q000379:methods*; D006620:Hip Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D017746:Joint Capsule / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D011859:Radiography; D012008:Recurrence; D012086:Reoperation / Q000379:methods; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome