Purpose: The Femoral Neck System (FNS) is a relatively new fixation device used to treat femoral neck fractures (FNFs). The Tip-Apex Distance (TAD) has been proven to effect outcomes of traditional fixation implants such as sliding hip screws (SHS). However, it is unclear if the TAD has the same effect on FNS outcomes. The purpose of this study was to assess if the TAD is a predictor of FNS fixation implant failure in FNFs. Furthermore, the outcomes of FNS at our institution as well as risk factors for failure were assessed.

Methods: This retrospective, single-centre study included 62 patients who underwent FNS for FNFs between 2017-2022. Clinical, radiographic, and pre/peri/post-operative data were described. Implant failure was defined as the presence of complications like mechanical failure (cut-out or breakage), avascular necrosis (AVN) or neck shortening.

Results: Mean age of the cohort was 69.6 years. Average follow up duration was 13.3 months. Failure rate was 11.3%, consisting of 2 cut-outs, 3 AVN, 1 femoral neck shortening and 1 distal screw breakage. Mean TAD was 16.8mm and 18.2mm in the failure and non-failure groups respectively. Osteoporosis prevalence was 71.4% in failure group and 43.6% in non-failure group. No significant difference was found between failure and non-failure groups regarding pre-operation Gardens class, Body Mass Index (BMI) and Charlson Comorbidity Index (CCI). Mean operation duration: 54.7 minutes. Mean length of stay in acute hospital: 9.2 days.

Conclusion: The TAD is not a predictor of implant failure and does not affect outcomes of FNS for treatment of FNFs. Additionally, the FNS is shown to be a reliable device with a low failure rate, operation time and length of hospital stay that is comparable with previous studies and other implants.