DYNAMIC HIP SCREW: ARE WE DOING IT ACCURATELY?

Abstract

BackgroundDynamic Hip Screw (DHS) is the most frequently used implant in management of intertrochanteric femoral fractures. There is a known statistical relationship between a tip-apex distance (TAD) >25mm and higher rate of implant failure. Our aim was to analyse all DHS procedures performed in our trust from seventeen months and compare their TAD values to the acceptable standard of ≤25mm.MethodsAll patients undergoing DHS between April 2020-August 2021 were identified from our theatre system. Additionally, those presenting to hospital with implant failures were included. Patient demographics, date of surgery, fracture classification (AO) and date/mode of failure were recorded. Intraoperative fluoroscopy images were reviewed to calculate TAD, screw location and neck shaft angles by two independent observers.Results215 patients were identified, five of which were excluded due to inadequate fluoroscopy. Failure was seen in 3.3% of the cohort (n=7), of which 71.4% had an unacceptable TAD. In total, 21 patients (10%) had TAD >25mm, of whom 12 had superiorly and 15 had posteriorly placed screws. There were no failures in patients with a TAD of <20mm whereas a TAD >30mm had 50% failure rateConclusionThis audit reinforces the importance of aiming for a low TAD (preferably <20mm) intraoperatively. It is also desirable to avoid superiorly and significantly posteriorly placed screws.ImplicationsComplex hip revision surgery in the elderly bears substantial financial implications to the NHS and, more importantly, causes prolonged morbidity to the patient. Adhering to established standards will ensure reduced implant failure and best patient care.