Is the tip-apex distance a reliable predictor of implant failure in surgical fixation of femoral neck fractures with the synthes femoral neck system device?

Mean age was 69.6 years old. Mean follow-up was 20.4 months. Median operation duration was 53.5 minutes. Median length of stay was 9 days. Failure rate was 15.2% (n = 7), consisting of two cut-outs, three AVN, one neck shortening and one distal screw breakage. Re-operation rate was 8.7% (n = 4). Mean TAD was 16.8 mm and 18.1 mm in the failure and non-failure groups respectively (P = 0.431) and was not a significant risk factor for failure on logistic regression testing (p = 0.444). Osteoporotic BMD value was more prevalent in the failure group (71.4%) but was not a significant risk factor for failure on logistic regression (P = 0.056). Quality of reduction, age, body mass index (BMI) and pre-operative Garden's score were also insignificant on logistic regression. (P > 0.05) CONCLUSION: The TAD is not a reliable predictor of FNS implant failure for treatment of FNFs. Overall, the FNS is a reliable device with a low failure rate, a short operative time, and a short length of stay comparable to that reported in the literature and with traditional implants.