A NEW LOCKING PLATE AND DYNAMIC SCREW SYSTEM FOR INTERNAL FIXATION OF INTRACAPSULAR HIP FRACTURES; RESULTS FOR THE FIRST 200 PATIENTS TREATED

Abstract

The Targon Femoral Neck Hip Screw has been designed to improve the fixation of intracapsular hip fractures. Fracture healing complications after internal fixation occur in approximately 30–40% of displaced fractures and 5–10% of undisplaced fractures. The new implant consists of a small plate with six locking screw ports. The two distal holes are used to fix the plate to the lateral cortex of the femur. Three of four screws are passes through the proximal holes and across the fracture site. These 6.5mm screws are dynamic to allow for collapse of the fracture across the femoral neck. A jig is used to aid insertion of the device with minimal surgical exposure of the femur.

For the first 200 patients treated with this implant at the first centre to use this implant, the mean age of the patients was 77 years (range 39–103), 58% were female. The mean length of surgery was 46 minutes and the mean length of anaesthesia 59 minutes. The median length of institutional stay till discharge home was 9 days (mean 13 days, range 3–107). Four telescoping screws were used in 55% of patients, three in 44% and two in 1% of patients.

Follow-up of patients at present is a minimum of six months. For the 74 undisplaced fractures there has been one case of non-union and one case of avascular necrosis. For the 121 displaced fractures (Garden III and IV) there have been eleven cases of fracture non-union, six cases of avascular necrosis and two cases of plate detachment from the femur treated by repeat fixation. In addition there was one deep wound sepsis treated by removal of the implant and girdlestone arthroplasty. For the four basal fractures treated there has been one case of plate detachment from the femur.

Observation of those fractures that have healed shows there has been between 0 to 22mm of collapse at the fracture site which occurs along the line of the femoral neck. There has been no tilting of the fracture into varus as occurs with a parallel screw method.

The results to date show an incidence of fracture healing complications is about a third that which is to be expected with a parallel screw method. This new implant may be a significant advance in the treatment of this difficult and common fracture.