There is an increasing incidence of revision for periprosthetic joint infection. The addition of vancomycin to beta-lactam antimicrobial prophylaxis in joint arthroplasty may reduce surgical site infections, however, the efficacy and safety have not been established.

This was a multicenter, double-blind, superiority, placebo-controlled trial. We randomized 4239 adult patients undergoing joint arthroplasty surgery to receive 1.5g vancomycin or normal saline placebo, in addition to standard cefazolin antimicrobial prophylaxis. The primary outcome was surgical site infection at 90-days from index surgery. Perioperative carriage of Staphylococcus species was also assessed.

In the 4113 patients included in the modified intention-to-treat population, surgical site infections occurred in 72/2069 (3.5%) in the placebo group and 91/2044 (4. 5%) in the vancomycin group (risk ratio 1.28; 95% confidence interval 0.94 to 1.73; p value 0.11). No difference was observed between the two groups for primary hip arthroplasty procedures. A higher proportion of infections occurred in knee arthroplasty patients in the vancomycin group (63/1109 [4.7%]) compared with the placebo group (42/1124 [3.7%]; risk ratio 1.52; 95% confidence interval 1.04 to 2.23; p value 0.031). Hypersensitivity reactions occurred in 11 (0.5%) patients in the placebo group and 24 (1.2%) in the vancomycin group (risk ratio 2.20; 95% confidence interval 1.08, 4.49) and acute kidney injury in 74 (3.7%) patients in the placebo group and 42 (2.1%) in the vancomycin group (risk ratio 0.57; 95% confidence interval 0.39, 0.83). Perioperative Staphylococcus aureus carriage was detected in 1089/3748 (29.1%) of patients.

This is the first randomized controlled trial examining the addition of a glycopeptide antimicrobial to standard beta-lactam surgical antimicrobial prophylaxis in joint arthroplasty. The addition of vancomycin to standard cefazolin prophylaxis was not superior to placebo for the prevention of surgical site infections in hip and knee arthroplasty surgery.

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.

Background: The combination of imageless computer aided navigation and minimally invasive surgery for total knee arthroplasty (TKA) has not been reported. Computer Aided Surgery (CAS) of the knee has demonstrated more reproducible component alignment compared to standard instrumentation. Minimally Invasive Surgery (MIS) for total knee arthroplasty allows for quicker rehabilitation and less post-operative pain. However, MIS has been associated with a higher complication rate, including component malalignment, compared to a conventional operative approach. Both MIS and CAS have been demonstrated to have a learning curve.

Aims: This study presents the initial 30 procedures in which imageless CAS was combined with MIS for TKA by the senior author. Specifically, we examined the accuracy of coronal alignment and the learning curve associated with the combined technique.

Between 6 and 12 weeks full length weight bearing radiographs were taken when patients could achieve full extension. Coronal alignments of the tibial and femoral components were calculated relative to the mechanical axis. The goal for both femoral and tibial component alignment was within 30 of 900 to the mechanical axis. The results were verified by an independent observer. Analysis of sequential tourniquet times, complication rates and component alignment were used as measure of the learning curve for the technique.

Component position was acceptable for all implants. The mean coronal tibial alignment was 90.35 degrees (range 88 to 92 degrees) and the mean coronal femoral alignment 90.10 degrees (range 88 to 93 degrees) to the mechanical axis. Tourniquet time averaged 90 minutes (range 60 to 118 minutes). There was no significant reduction in tourniquet time with increasing familiarity with the technique. Our results demonstrate that CAS combined with MIS for TKA maintains the accuracy of component alignment despite the minimally invasive approach. These initial results demonstrate no significant learning curve associated with the technique.