Abstract
The Femoral Neck System (FNS) was introduced as an alternative device for the fixation of neck of femur fractures (NOFFs). The purported advantages include superior angular and rotatory stability compared to multiple cancellous screws, via a minimally invasive instrumentation that is simpler than conventional fixed angle devices. There were limited clinical studies regarding the utility of this device. We aimed to study the outcomes of NOFFs fixed with the FNS.
This was a single-institution, retrospective review of all undisplaced elderly (≥60 years old) undisplaced young, and displaced young NOFFs fixed with the FNS. Demographics, surgical parameters, radiographic parameters, and clinical outcomes including complications were reviewed.
Thirty-six subjects with a median age of 75 [44,89] years old, had NOFF fixation using the FNS. Thirty-one (86.1%) had undisplaced fractures. There were 6 (16.7%), 26 (72.2%), and 4 (11.1%) subjects with Pauwels types 1, 2, and 3 respectively. Thirty-two (88.9%) had posterior tilt of <20º. The mean duration of surgery was 71±18 minutes. Excluding 4 patients whom required revision surgery, 2 patients whom demised, and 10 patients whom defaulted reviews, the mean follow-up duration was 55±13 weeks. Four complications were recorded, namely implant cut out at the femoral head at week 8, breaking of the locking screw at the run-off region at week 22, avascular necrosis at week 25, and a refracture following near fall, causing the fracture to fail in varus at week 7 postoperation.
While reasonably fast to instrument, failures still occur and it is likely multifactorial. However, the rate of reoperation is lower than what has been reported for NOFFs fixed with the a fixed-angle device or 3 cancellous screws. In conclusion, the FNS is a reasonably safe instrument to use. Surgeons’ discretion is still needed in patient selection, keeping in mind the need for satisfactory radiological parameters.
