Pitfalls in implantation of InterTAN for intertrochanteric femur fracture

Abstract

Objective To investigate the intraoperative technical difficulties in the implantation of InterTAN for intertrochanteric femur fracture and their countermeasures. Methods A retrospective study was conducted of the 496 patients with intertrochanteric femur fracture who had been treated with InterTAN intramedullary nails from September 2008 to August 2013 at our department. They were 172 men and 324 women, aged from 32 to 87 years at the time of fracture (average, 69.2 years). According to the AO classification, 29 cases were type 31-A1, 315 cases type 31-A2 and 152 cases type 31-A3. Intraoperative difficulties in implantation of InterTAN intramedullary nails were analyzed and countermeasures were proposed. Results We identified intraoperative technical difficulties in implantation of the main nail in the following situations: in 21 patients who had anatomic variation in femoral shaft (excessive anterior or lateral skewing), in 5 obese patients in one of whom iatrogenic fracture occurred; in 3 elderly patients, and in 17 patients with hard reduction in one of whom iatrogenic fracture occurred during the locking of a distal screw. Conclusions To deal with the difficulties in implantation of InterTAN for intertrochanteric femur fracture we propose the following 4 countermeasures: 1. Anteroposterior and lateral radiographs of the full length of the injured femur are necessary for preoperative determination of presence or absence of anatomical variations so that implantation can be adjusted during surgery. 2. Vertical trajectory and sufficient reaming in the medullar canal of the proximal femur are important to reduce the possibility of iatrogenic fracture, particularly in obese patients. 3. Violent hammering is prohibited and full reaming is recommended in the elderly whose bone is fragile. 4. For the cases where hard fracture reduction is predicted by the preoperative evaluation, the strategy of open reduction and fixation with dynamic hip screws seems more rational or should be prepared as an alternative method. Key words: Hip fractures; Fracture fixation, internal; Bone nails; Implantation difficulties