Tip-apex distance (TAD) has long been discussed as a metric for determining risk of failure in fixation of peritrochanteric hip fractures. This study seeks to investigate risk factors including
It is widely accepted that a tip apex distance of greater than 25mm is associated with dynamic hip screw (DHS) failure and cut-out. The aim was to devise an accurate and easy method for calculation of DHS tip apex distance (TAD) from intraoperative imaging using the tools available on Kodac Picture Archiving and Communications System. This method was applied to all patients treated with a DHS for intertrochanteric hip fracture during a six month period. Any subsequent radiographs were assessed for evidence of failure within 18 months. The
A tip-apex distance (TAD) greater than 25 mm is a strong predictor of screw cut-out in patients with intertrochanteric femoral fracture treated with a dynamic hip screw (DHS). We aim to show you a simple and reliable way to check this. By calculating the sum of the distance from the tip of the screw to the apex of the femoral head on anteroposterior and lateral views the
Background. Hip fractures cause significant morbidity and mortality, affecting 70,000 people in the UK each year. The dynamic hip screw (DHS) is used for the osteosynthesis of extracapsular neck of femur fractures, a procedure that requires complex psychomotor skills to achieve optimal lag screw positioning. The tip-apex distance (TAD) is a measure of the position of the lag screw from the apex of the femoral head, and is the most comprehensive predictor of cut-out (failure of the DHS construct). To develop these skills, trainees need exposure to the procedure, however with the European Working Time Directive, this is becoming harder to achieve. Simulation can be used as an adjunct to theatre learning, however it is limited. FluoroSim is a digital fluoroscopy simulator that can be used in conjunction with workshop bones to simulate the first step of the DHS procedure (guide-wire insertion) using image guidance. This study assessed the construct validity of FluoroSim. The null hypothesis stated that there would be no difference in the objective metrics recorded from FluoroSim between users with different exposure to the DHS procedure. Methods. This multicentre study recruited twenty-six orthopaedic doctors. They were categorised into three groups based on the number of DHS procedures they had completed as the primary surgeon (novice <10, intermediate 10≤x<40 and experienced ≥40). Twenty-six participants completed a single DHS guide-wire attempt into a workshop bone using FluoroSim. The
Introduction and Aims. Peritrochanteric femur fractures are common and impose major costs on the healthcare system. A fixed angle sliding hip screw is the principle method of treatment, but the rate of mechanical failure associated with these devices can be high; the usual mechanism being the collapse of the neck shaft angle leading to extrusion of the screw from the femoral head, commonly known as “cutout”. Many variables contribute to the risk of cutout, however there is substantial evidence that the “Tip Apex Distance” (a single number that summarises the position and depth of the lag screw on anteroposterior and lateral radiographs after controlling for magnification) is the single best predictor of risk of failure. There is a strong statistical relationship between an increasing tip apex distance (TAD) and the rate of cutout. Specifically, a
Background. Training within surgery is changing from the traditional Halstedian apprenticeship model. There is need for objective assessment of trainees, especially their technical skills, to ensure they are safe to practice and to highlight areas for development. In addition, due to working time restrictions in both the UK and the US, theatre time is being limited for trainees, reducing their opportunities to learn such technical skills. Simulation is one adjunct to training that can be utilised to both assess trainees objectively, and provide a platform for trainees to develop their skills in a safe and controlled environment. The insertion of a dynamic hip screw (DHS) relies on complex psychomotor skills to obtain an optimal implant position. The tip-apex distance (TAD) is a measurement of this positioning, used to predict failure of the implant. These skills can be obtained away from theatre using workshop bone simulation, however this method does not utilise fluoroscopy due to the associated radiation risks. FluoroSim is a novel digital fluoroscopy simulator that can recreate digital radiographs with workshop bone simulation for the insertion of a DHS guide-wire. In this study, we present the training effect demonstrated on FluoroSim. The null hypothesis states that no difference will be present between users with different amounts of exposure to FluoroSim. Methods. Medical students were recruited from three London universities and randomised into a training (n=23) and a control (n=22) cohort. All participants watched a video explanation of the simulator and task and were blinded to their allocation. Training participants completed 10 attempts in total, 5 attempts in week one, followed by a one week wash out period, followed by 5 attempts in week 2. The control group completed a single attempt each week. For each attempt, 5 metrics were recorded;
Intramedullary fixation is considered the most stable treatment for pertrochanteric fractures of the proximal femur and cut-out is one of the most frequent mechanical complications. In order to determine the role of clinical variables and radiological parameters in predicting the risk of this complication, we analysed the data pertaining to a group of patients recruited over the course of six years. A total of 571 patients were included in this study, which analysed the incidence of cut-out in relation to several clinical variables: age; gender; the AO Foundation and Orthopaedic Trauma Association classification system (AO/OTA); type of nail; cervical-diaphyseal angle; surgical wait times; anti-osteoporotic medication; complete post-operative weight bearing; and radiological parameters (namely the lag-screw position with respect to the femoral head, the Cleveland system, the tip-apex distance (TAD), and the calcar-referenced tip-apex distance (CalTAD)).Objectives
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