James D. Sires

Introduction: Prosthetic joint infections (PJI) of the hip and knee have significant morbidity and mortality, and present with varying local, host and microbiological factors. Given the broad presentation and complexity of PJI’s, we developed a dedicated multidisciplinary team (MDT) to manage this complex patient cohort, and report on our early outcomes. Methods: This was a retrospective observational study of all patients diagnosed with a prosthetic joint infection of the hip or knee (n = 71) at our institution during a 4.5-year period. Patients treated after development of the MDT (post-MDT) (n = 44), were compared to a control group prior establishment of the MDT (pre-MDT) (n = 27). Results: 85.2% of individuals in the pre-MDT, and 85.7% of individuals in the post-MDT group were considered cured at a minimum 2 years post-operatively according to the Delphi-based definition. The total number of admissions to hospital (2.44 vs. 1.84) and total number of antibiotics used (3.37 vs. 2.75) decreased in the post-MDT group; however, differences were not considered statistically significant. Discussion: Implementation of a dedicated MDT in the management of individuals with PJI’s of the lower limb at our hospital has allowed early and effective collaboration between healthcare personnel, with early promising results. Given the broad nature of PJI, future studies are ongoing to determine modifiable risk factors to reduce the incidence and improve outcomes of individuals with PJI’s where systems can then be implemented into already established MDTs to achieve the best clinical outcome for our patients.

Background Paediatric neck injuries are a common presenting complaint to emergency departments (EDs). Medical imaging can assist diagnosis, however previous research suggests computed tomography (CT) scan results do not alter management in this patient group and therefore expose children to unnecessary radiation. Following an audit by the hospital Trauma Service that identified unnecessary cervical spine CTs in patients at Women's and Children's Hospital (WCH), Adelaide, the Clinical Procedure for imaging and clearance of the cervical spine in conscious patients was modified to include CT scan only at the request of the orthopaedic service. The aim of this study was to evaluate whether a change in hospital guideline resulted in a change in practice and radiation exposure. Methods A retrospective review was performed for patients that presented to the WCH ED with a suspected cervical spine injury during two defined time periods pre- and post-guideline change. Mechanism of injury, imaging requested, radiation exposure and final diagnosis were compared. Results Three hundred seventy-nine patients were included, with 164 (43.3%) post-guideline changes. Radiograph use was similar between groups, 132/215 (61.4%) versus 101/164 (61.6%) (p = 0.97). CT scan use was lower post-guideline modification 19/215 (8.8%) versus 12/164 (7.3%), however was not statistically significant (p = 0.59), with an absolute reduction of 17%. Conclusion Guideline modification at our hospital did not significantly reduce CT scan use or eliminate unnecessary CTs. Unnecessary CT scans followed lack of knowledge of and therefore compliance with guidelines. Individual hospitals should consider strategies to reduce unnecessary CTs, given the association with cancer risk in children.

Background Vascular anomalies comprise highly variable pathophysiology and commonly pose diagnostic and management dilemmas. Consequently, patients often benefit from input from multiple specialists. This study describes the inception of a multidisciplinary team (MDT) Vascular Anomaly Clinic (VAC) in a tertiary paediatric centre, and the subsequent experience managing this complex patient group. Methods This was a retrospective study of paediatric patients (< 18 years old) attending an MDT VAC from its inception in October 2012 until November 2019. Patient demographics, presentation, diagnosis and management were reviewed. Results One hundred and thirty-three paediatric patients were seen over 7 years with a median age of 9.8 years. Vascular malformations were the most common diagnosis (88%), with venous malformations predominating (27%). The most common symptoms were pain (46%) and swelling (34%). Patients often required ≥ 2 investigations, with Doppler ultrasound (86%) and magnetic-resonance imaging (61%) being most common. Management included surgery (27%), sclerotherapy (26%), compression garments (23%), analgesia (12%), laser (15%), embolisation (5%) and sirolimus (3%). Conclusions The complex nature of vascular anomalies and high proportion of patients requiring multi-specialty management justified the establishment of an MDT VAC in our centre. Our experience demonstrates the success of an efficient one-stop MDT environment in the management of these challenging conditions. Level of evidence IV

Robotic-assisted technology in total knee arthroplasty (TKA) aims to increase implantation accuracy, with real-time data being used to estimate intraoperative component alignment. Postoperatively, Perth computed tomography (CT) protocol is a valid measurement technique in determining both femoral and tibial component alignments. The aim of this study was to evaluate the accuracy of intraoperative component alignment by robotic-assisted TKA through CT validation. A total of 33 patients underwent TKA using the MAKO robotic-assisted TKA system. Intraoperative measurements of both femoral and tibial component placements, as well as limb alignment as determined by the MAKO software were recorded. Independent postoperative Perth CT protocol was obtained (n = 29) and compared with intraoperative values. Mean absolute difference between intraoperative and postoperative measurements for the femoral component were 1.17 degrees (1.10) in the coronal plane, 1.79 degrees (1.12) in the sagittal plane, and 1.90 degrees (1.88) in the transverse plane. Mean absolute difference between intraoperative and postoperative measurements for the tibial component were 1.03 degrees (0.76) in the coronal plane and 1.78 degrees (1.20) in the sagittal plane. Mean absolute difference of limb alignment was 1.29 degrees (1.25), with 93.10% of measurements ≤3 degrees of postoperative CT measurements. Overall, intraoperatively measured component alignment as estimated by the MAKO robotic-assisted TKA system is comparable to CT-based measurements.

Accurate component positioning and planning is vital to prevent malalignment of total knee arthroplasty (TKA) as malalignment is associated with an increased rate of polyethylene wear and revision arthroplasty. The MAKO total knee robotic arm-assisted surgery (Stryker, Kalamazoo, MI) uses a preoperative computed tomography scan of the patient's knee and three-dimensional planning to size and orientate implants prior to bone resection. The aim of this study was to determine the accuracy of the MAKO Total Knee system in achieving the preoperative plan for bone resection and final limb coronal alignment. A series of 45 consecutive cases was performed using the MAKO Total Knee system and Triathlon Total Knee implant (Stryker) between April 2018 and May 2019. The difference between what was planned and what was achieved for bone resection and coronal limb alignment was calculated. A total of 37 patients had their data captured using the MAKO system software. Mean difference from the plan for distal femoral cuts was 0.38mm (0.32) deep/proud, anterior femoral cuts 0.44mm (0.27) deep/proud and tibial cuts 0.37mm (0.30) deep/proud. In total, 99 out of 105 (94.29%) of bone resections were within 1mm of the plan. Mean absolute difference in final limb coronal alignment was 0.78° (0.78), with 78.13% being ≤1.00° of the plan, and 100% being ≤3.00° of the plan. The accuracy in achieving preoperatively planned bone resection and final limb coronal alignment using the MAKO Total Knee system is high. Future research is planned to look at whether this is associated with decreased rates of polyethylene wear and revision arthroplasty.