A finite element study was carried out to compare the performance of a three-hole locking plate with angled screws to the ‘gold-standard’ four-hole hip plate. Two cases of the three-hole hip plate were examined; (a) three screws and (b) two screws (most proximal and most distal).

A 3D model of the proximal femur was constructed from CT scans. A 3D CAD model of the four-hole hip plate was also created. The three-hole hip plate was then created from the four-hole implant in a way that it was possible to switch between all three models by activating/deactivating sections and/or switching material properties. A single common finite element model was generated, and a static analysis of each model variation was then performed in two steps using ABAQUS/standard. In the first, screws were pre-tensioned up to 150N. In the second, loads corresponding to stair climbing were applied.

Forces in the screws, permitted to change in the second step, were examined and compared. Maximum principal stresses in the bone were also examined, with a focus on the stresses in the bone at the end of the plate in each model. The highest tensile force was in the proximal screw of the three-hole plate with three screws, followed by the most distal screw in the standard four-hole plate. This suggests that the risk of screw pull-out is highest at the proximal screw of the three-hole hip plate with three screws.

A comparison of the forces in the distal screws for all cases shows that the highest tensile force was in the four-hole plate, followed by the three-hole plate with two screws. The lowest was the three-hole plate with three screws, which was in compression at full load. The maximum tensile stresses in the bone at the end of the plate were greatest for the standard four-hole hip plate, followed by the three-hole plate with two screws and then the three-hole plate with three screws. This indicates that the risk of bone fracture at the end of the plate is lowest for the three-hole hip plate with three screws.

The risk of bone fracture is significantly lower for the three-hole hip plate, with either two or three screws, compared to the ‘gold-standard’ four-hole hip plate. This is partially offset by a small increase in the risk of screw pull out (in the proximal rather than the distal screw).

Thromboprophylaxis for venous thromboembolism (VTE) after elective arthroplasty remains controversial. Previous surveys have shown considerable variation amongst orthopaedic surgeons, and the topic is still being debated. Chest physicians recently advocated that randomised data demonstrating a risk reduction with long- established thromboprophylaxis have been ignored by orthopaedic surgeons. We present the current thromboprophylaxis practice amongst AOA members performing elective hip and knee replacements and discuss its rationale.

All orthopaedic surgeons in the AOA were asked to complete a one page postal questionnaire asking for information regarding: whether they performed elective hip or knee arthroplasty, which methods of mechanical and/or chemical prophylaxis were routinely used, the time frame in ceasing thromboprophylaxis, the motive in using thromboprophylaxis, and whether thromboprophylaxis guidelines released by the AOA or RACS would be helpful in their orthopaedic practice.

Responses from the survery are currently being collected and analysed. These results will be ready for presentation at the AOA conference.

The results of the survey will be presented in addition to a discussion of the rationale behind current use of post-operative thromboprophylaxis for elective hip and knee arthroplasty and a need for clinical guidelines.

Multimodal analgesia protocols for pain control following total joint arthroplasty can reduce post-operative pain, allow early mobilisation and early discharge from hospital.

This study analyses the achievement of functional milestones, patient satisfaction, length of stay and adverse outcomes using a multimodal analgesia protocol in total joint arthroplasty.

All patients planned for elective hip and knee arthroplasty in a NSW teaching hospital under one surgeon between July 2007 and January 2009 were included in this prospective study. Patients undergoing revision surgery, bilateral arthroplasty or total hip arthroplasty for fractures were excluded. Unless contraindicated, all patients followed the multimodal analgesia protocol based on the local infiltration analgesia technique described by Kerr and Kohan.