Biomechanics is an essential form of measurement in the understanding of the development and progression of osteoarthritis (OA). However, the number of participants in biomechanical studies are often small and there is limited ways to share or combine data from across institutions or studies. This is essential for applying modern machine learning methods, where large, complex datasets can be used to identify patterns in the data. Using these data-driven approaches, it could be possible to better predict the optimal interventions for patients at an early stage, potentially avoiding pain and inappropriate surgery or rehabilitation. In this project we developed a prototype database platform for combining and sharing biomechanics datasets. The database includes methods for importing and standardising data and associated variables, to create a seamless, searchable combined dataset of both healthy and knee OA biomechanics. Data was curated through calls to members of the OATech Network+ (Abstract
Objectives
Methods
Over 10% of total hip arthroplasty (THA) surgeries performed in England and Wales are revision procedures1. Malorientation of the acetabular component in THA may contribute to premature failure due to mechanisms such as edge loading and prosthetic impingement. It is known that the pelvis flexes and extends during activities of daily living (ADLs), and excessive pelvic motion can contribute to functional acetabular malorientation. Preoperative radiographs can be performed to measure changes in pelvic tilt during ADLs to identify high risk individuals and inform surgical decision making. However, radiographs require time-consuming radiation exposure, and are unable to provide truly dynamic 3-dimensional analysis. The purpose of this study was to develop and evaluate a motion capture method using inertial measurement units (IMUs). This would provide a rapid, non-invasive analysis of pelvic tilt which could be used to support surgical planning. Patients awaiting THA were fitted with a bespoke device consisting of a 3D-printed clamp which housed the IMU and positioned over the sacrum. A wide elastic belt was fitted around the patient's waist to keep the device in place. Movement data was transmitted wirelessly to a tablet computer. Pelvic tilt was measured in standing, flexed seated and step-up positions while undergoing X-rays with the IMU capturing the data in parallel. Statistical analysis included measures of correlation between the X-ray and IMU measurements.Background
Methods
It is not always clear why some patients experience recurrent dislocation following total hip arthroplasty (THA). In order to plan appropriate revision surgery for such patients, however, it is important to understand the specific biomechanical basis for the dislocation. We have developed a novel method to analyse the biomechanical profile of the THA, specifically to identify edge loading and prosthetic impingement, taking into account spinopelvic mobility. In this study we compare the results of this analysis in THA patients with and without recurrent dislocation. Post-operative CT scans and lateral standing and seated radiographs of 40 THA patients were performed, 20 of whom had experienced postoperative dislocation. The changes in pelvic and femoral positions on the lateral radiographs were measured between the standing and seated positions, and a 3D digital model was then generated to simulate the movement of the hip when rising from a chair for each patient. The path of the joint reaction force (JRF) across the acetabular bearing surface and the motion of the femoral neck relative to the acetabular margin were then calculated for this “sit-to-stand” movement, in order to identify where there was risk of edge loading or prosthetic impingement.Background
Methods
Infection and re-fracture are well-described complications following open paediatric forearm fractures. The purpose of this paper is to determine if patient, injury, and treatment characteristics can be used to predict the occurrence of these complications following the surgical management of paediatric open forearm fractures. This is an IRB-approved retrospective review at a single-institution paediatric level 1 trauma centrefrom 2007–2013 of all open forearm fractures. Medical records were reviewed to determine the type of open fracture, time to administration of initial antibiotics, time from injury to surgery, type of fixation, length of immobilisation, and complications. Radiographs were studied to document fracture characteristics. 262 patients with an average age of 9.7 years were reviewed. There were 219 Gustillo-Anderson Type 1 open fractures, 39 Type 2 fractures, and 4 Type 3 fractures. There were 9 infections (3.4%) and 6 re-fractures (2.3%). Twenty-eight (10.7%) patients returned to the operating room for additional treatment; 21 of which were for removal of implants. Contaminated wounds, as documented within the medical record, had a greater chance of infection (21% vs 2.2%, p=0.002). No difference in infection rate was seen with regard to timing of antibiotics (p=0.87), timing to formal debridement (p=0.20), Type 1 versus Type 2 or 3 open fractures (3.4% vs 5.0%, p=0.64), 24 hours vs. 48 hours of post-operative IV antibiotics (5.2% vs 3.5%, p=0.53), or when comparing diaphyseal, distal, and Monteggia fracture patterns (3.6 vs 2.9% vs 5.9%, p=0.81). There was no difference in infection rate when comparing buried or exposed intramedullary implants (3.5% vs 4.2%, p>0.99). Rate of re-fracture was not increased based on type of open wound (p>0.99) or fracture type (0.4973), although 5 of the 6 re-fractures were in diaphyseal injuries. In this series of open paediatric both bone forearm fractures, initial wound contamination was a significant risk factor for subsequent infection. The rate of infection did not vary with timing of antibiotics or surgery, type of open fracture, or length of post-operative antibiotics. A trend to higher re-fracture rates in diaphyseal injuries was noted. Surgeons should consider planned repeat irrigation and debridement for open forearm fractures with obviously contaminated wounds to reduce the subsequent infection risk.
A new 28mm-diameter ceramic-on-ceramic (COC) acetabular bearing couple (Biomet Orthopedics) showed extremely low wear, even under adverse microseparation conditions∗. The wear results are similar or more favorable than those reported for clinical retrievals and wear testing of similar ceramic bearings. A new acetabular shell and ceramic insert design (Biomet) incorporates features to help prevent malalignment during implantation, while still providing secure fixation within the acetabular shell. The incorporation of Biolox® Delta (zirconia toughened alumina, CeramTec) material should provide improved wear resistance over pure alumina ceramics. The goal of this study is to evaluate the wear durability of this system for standard and microseparation testing.Summary Statement
Introduction
