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RATIONALE, AIMS AND OBJECTIVES: The demand for arthroplasty is increasing and will continue to rise with an ageing population. Obesity and lengthy waiting time for Total Joint Replacement (TJR) have been associated with poorer outcomes postoperatively. This study aimed to evaluate the Multi-Attribute Prioritisation Tool (MAPT) for TJR patients. The primary objective was to explore if patients prioritised by the MAPT had an improvement in score post-operative. Further to identify any relationship between MAPT score and length of time on the waiting list or obesity. METHOD: This retrospective cohort study included 308 patients undergoing total hip (n = 114) or total knee (n = 194) arthroplasty. We examined preoperative and postoperative MAPT scores of patients who had total hip or total knee arthroplasty. After assessing the difference between postoperative and preoperative MAPT scores, patients scores were compared to BMI and waiting time classes. BMI was allocated to less than 30, 30–35, 35–40 and greater than 40. Duration of time on the waiting list was allocated to less than 6 months and greater than 6 months. RESULTS: THA and TKA patients MAPT scores improved from a preoperative score of 71.39–5.26 postoperative and 54.11 to 7.13 respectively. Patients whose MAPT scores placed them in the high priority category had a significant relationship with length of time on the waiting list (p

The magnitude and pattern of acceptable long-term migration of cementless femoral stems are not well understood. The Corail hydroxyapatite-coated cementless stem is a clinically successful and commonly used femoral stem with a long-term migration pattern not previously described in the literature. The aim of this study was to assess the long-term migration of the Corail hydroxyapatite-coated cementless stem using radiostereometric analysis (RSA) at 14-year follow-up, thereby establishing a benchmark acceptable long-term migration pattern for hydroxyapatite-coated cementless prostheses. A prospective cohort of 29 patients (30 hips) undergoing primary total hip arthroplasty for primary hip osteoarthritis were enrolled into a study to characterise the migration of the Corail cementless stem. A total of 13 patients (4 males, 9 females) with mean age 82 (range 68–92) underwent repeat RSA radiographs at minimum 10 years post-operation (mean 13.9 years, range 13.3–14.4). Subsidence of the stem was measured and compared to prior measurements taken at 6 months and 1, 2, and 6 years. None of the 13 patients have been revised. The migration at 6 months, 1 year, 2 years, and 6 years has been previously recorded. At mean 14-year follow-up, the cohort mean subsidence of the cementless stem was 0.70 mm (range − 0.06 to 3.61 mm). For each stem followed up at 6 months and 14 years, the mean subsidence over this period was 0.05 mm (range − 0.14 to 0.57 mm). There is no significant difference in mean subsidence at 6 months and 14 years (p = 0.43). The long-term pattern of the subsidence of the Corail femoral stem has not previously been described. Subsidence occurs within the first 6 months, after which there is persistent stabilisation of the implant to 14 years. This study provides a description of a long-term acceptable migration pattern to which new hydroxyapatite-coated cementless prostheses may be compared. II.

Tibial subchondral bone plays an important role in knee osteoarthritis (OA). Microarchitectural characterisation of subchondral bone plate (SBP), underlying trabecular bone (STB) and relationships between microarchitecture in these compartments, however, is limited. The aim of this study was to characterise the spatial distribution of SBP thickness and porosity and STB microarchitecture, and relationships between compartments, in OA tibiae of varying joint alignment. Twenty-five tibial plateaus from end-stage knee-OA patients, with varus (n= 17) or non-varus (n= 8) alignment were micro-CT scanned (17µm/voxel). SBP and STB microarchitecture was quantified via a systematic mapping in 22 volumes of interest per knee (11 medial, 11 lateral). Significant within-condylar and between-condylar (medial vs. lateral) differences (p

Incidence of total hip arthroplasties being performed is on a rise across the world, consequently we would see more and more revisions hip arthroplasties being done for various indications such as infection, loosening, wear, metallosis, trauma; alone or a combination of the above factors. This case report highlights one of the rare but interesting scenarios that a revision hip surgeon must be prepared to encounter while planning to perform a technically challenging revision hip arthroplasty surgery. This report also thus emphasizes the importance of extensive pre-operative planning in terms of technique and timing of the procedure, the skills set and the armamentarium of tools that may be needed for a demanding revision arthroplasty procedure.

Objective: To study, in end-stage knee osteoarthritis (OA) patients, relationships between indices of in vivo dynamic knee joint loads obtained pre-operatively using gait analysis, static knee alignment, and the subchondral trabecular bone (STB) microarchitecture of their excised tibial plateau quantified with 3D micro-CT. Design: Twenty-five knee OA patients scheduled for total knee arthroplasty underwent pre-operative gait analysis. Mechanical axis deviation (MAD) was determined radiographically. Following surgery, excised tibial plateaus were micro-CT-scanned and STB microarchitecture analysed in four subregions (anteromedial, posteromedial, anterolateral, posterolateral). Regional differences in STB microarchitecture and relationships between joint loading and microarchitecture were examined. Results: STB microarchitecture differed among subregions (P < 0.001), anteromedially exhibiting highest bone volume fraction (BV/TV) and lowest structure model index (SMI). Anteromedial BV/TV and SMI correlated strongest with the peak external rotation moment (ERM; r = -0.74, r = 0.67, P < 0.01), despite ERM being the lowest (by factor of 10) of the moments considered, with majority of ERM measures below accuracy thresholds; medial-to-lateral BV/TV ratios correlated with ERM, MAD, knee adduction moment (KAM) and internal rotation moment (|r|-range: 0.54-0.74). When controlling for walking speed, KAM and MAD, the ERM explained additional 11-30% of the variations in anteromedial BV/TV and medial-to-lateral BV/TV ratio (R 2 = 0.59, R 2 = 0.69, P < 0.01). Conclusions: This preliminary study suggests significant associations between tibial plateau STB microarchitecture and knee joint loading indices in end-stage knee OA patients. Particularly, anteromedial BV/TV correlates strongest with ERM, whereas medial-to-lateral BV/TV ratio correlates strongest with indicators of medial-to-lateral joint loading (MAD, KAM) and rotational moments. However, associations with ERM should be interpreted with caution. Refereed/Peer-reviewed

One cross-linked polyethylene (XLPE) liner is manufactured using a lower dose of radiation, 5 Mrad, which may result in less cross-linking. The reported in vivo wear rate of this XLPE liner in patients undergoing THA has varied, and has included some patients in each reported cohort who had greater than 0.1 mm/year of wear, which is an historical threshold for osteolysis. Previous studies have measured wear on plain radiographs, an approach that has limited sensitivity.We therefore measured the amount and direction of wear at 6 years using Radiostereometric analysis (RSA) in patients who had THAs that included a cross-linked polyethylene liner manufactured using 5 Mrad radiation.We prospectively reviewed wear in 30 patients who underwent primary THAs with the same design of cross-linked acetabular liner and a 28-mm articulation. Tantalum markers were inserted during surgery and all patients had RSA radiographic examinations at 1 week, 6 months, 1, 2, and 6 years postoperatively.The mean proximal, two-dimensional (2-D) and three-dimensional (3-D) wear rates calculated between 1 year and 6 years were 0.014, 0.014, and 0.018 mm/per year, respectively. The direction of the head penetration recorded between 1 week and 6 years was in a proximal direction for all patients, proximolateral for 16 of 24 patients, and proximomedial for eight of 24 patients.The proximal, 2-D and 3-D wear of a XLPE liner produced using 5 Mrad of radiation was low but measurable by RSA after 6 years. No patients had proximal 2-D or 3-D wear rates exceeding 0.1 mm/year. Further followup is needed to evaluate the effect of XLPE wear particles on the development of long-term osteolysis.

Objectives: To (1) stratify patient subgroups according to their distinct walking gait patterns in end-stage knee osteoarthritis (OA); (2) compare measures of joint loading and proximal tibia subchondral trabecular bone (STB) microarchitecture among these gait subgroups. Design: Twenty-five knee OA patients undergoing total knee arthroplasty (TKA) had pre-operative gait analysis. Following surgery, excised tibial plateaus were micro-CT-scanned and STB microarchitecture analysed in four tibial condylar regions of interest. Peak knee moments were input to k-means cluster analysis, to identify subgroups with homogeneous gait patterns. Joint loading and STB microarchitecture parameters were compared among gait subgroups (Kruskal-Wallis, Bonferroni-corrected Mann-Whitney U tests). Results: Three gait subgroups were revealed: biphasics (n = 7), flexors (n = 9), counter-rotators (n = 9). Peak knee adduction moment (KAM) and KAM impulse were significantly higher (P < 0.05) in biphasics than in flexors and counter-rotators (KAM = -0.65, -0.40 and -0.21 Nm/kg, respectively), suggesting a higher medial-to-lateral tibiofemoral load ratio in biphasics. Interestingly, STB medial-to-lateral bone volume fraction (BV/TV) ratio was also significantly higher (more than double) in biphasics and flexors than in counter-rotators (2.24, 2.00 and 1.00, respectively), whereas in biphasics it was only 10% higher than in flexors and not significantly so. Conclusions: Within the confines of the limited sample size, data suggests that different mechanisms between the biphasic and flexor gait subroups may generate comparable loads upon the tibial plateau and corresponding bony responses, despite significantly lower KAM indices in flexors. Hence, in flexor gait OA patients, conservative treatments designed to reduce KAM, may not be appropriate. Understanding joint loading among walking gait patterns and relationships to bone microarchitecture may aid at identifying/improving management of persons at risk for developing knee OA. Refereed/Peer-reviewed

Tibial subchondral bone plays an important role in knee osteoarthritis (OA). Microarchitectural characterization of subchondral bone plate (SBP), underlying subchondral trabecular bone (STB) and relationships between these compartments, however, is limited. The aim of this study was to characterize the spatial distribution of SBP thickness, SBP porosity and STB microarchitecture, and relationships among them, in OA tibiae of varying joint alignment. Twenty-five tibial plateaus from end-stage knee-OA patients, with varus (n = 17) or non-varus (n = 8) alignment were micro-CT scanned (17 μm/voxel). SBP and STB microarchitecture was quantified via a systematic mapping in 22 volumes of interest per knee (11 medial, 11 lateral). Significant within-condylar and between-condylar (medial vs. lateral) differences (p 0.05) were found. In varus, STB bone volume fraction (BV/TV) was consistently high throughout the medial condyle, whereas in non-varus, medially, it was more heterogeneously distributed. Regions of high SBP thickness were co-located with regions of high STB BV/TV underneath. In varus, BV/TV was significantly higher medially than laterally, however, not so in non-varus. Moreover, region-specific significant associations between the SBP thickness and SBP porosity and the underlying STB microarchitecture were detected, which in general were not captured when considering the values averaged for each condyle. As subchondral bone changes reflect responses to local mechanical and biochemical factors within the joint, our results suggest that joint alignment influences both the medial-to-lateral and the within-condyle distribution of force across the tibia, generating corresponding local bony responses (adaptation) of both the subchondral bone plate and underlying subchondral trabecular bone microarchitecture. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1927-1941, 2017.

We present the case of a patient with intraoperative femoral fracture during THA, which was repaired using cerclage fixation and insertion of an hydroxyapatite-coated cementless stem. The patient was evaluated postoperatively using radiostereometry during a 2-year course, and despite a large amount of subsidence and rotation, stabilization occurred and was maintained by 6 months. By evaluating the pattern of stem migration after intraoperative fracture, this case shows, even in the presence of instability, a successful clinical outcome can be achieved using an hydroxyapatite-coated cementless stem.

Measurement of early stem subsidence can be used to predict the likelihood of long-term femoral component loosening and clinical failure. Data that examines the early migration pattern of clinically proven stems will provide clinicians with useful baseline data with which to compare new stem designs. This study was performed to evaluate the early migration pattern of a hydroxyapatite-coated press-fit femoral component that has been in use for over ten years. We enrolled 30 patients who underwent THA for osteoarthritis. The median age was 70 years (range, 55–80 years). Patients were clinically assessed using the Harris hip score. Radiostereometric analysis was used to evaluate stem migration at three to four days, six months, one year and two years. We observed a mean subsidence of 0.73 mm at six months, 0.62 mm at one year and 0.58 mm at two years and a mean retroversion of 1.82° at six months, 1.90° at one year and 1.59° at two years. This data suggests that subsidence is confined to the first six months after which there was no further subsidence. The results from this study can be compared with those from novel cementless stem designs to help predict the long-term outcome one may expect from new cementless stem designs.

Wear induced peri-prosthetic osteolysis and aseptic loosening remain the major contributing factors to failure of total hip arthroplasty. To reduce wear particles from acetabular liners, the process of polyethylene cross-linking has been modified. In this study, we examine the wear of Marathon™ acetabular liners using Radiostereometric Analysis. Thirty patients were enrolled in a prospective cohort study. Femoral head penetration was calculated for 25 patients at 6 months, 1 and 2 years postoperatively. The mean proximal head penetration was 0.067 mm at 6 months, 0.113 mm at 1 year and 0.120 mm at 2 years. The mean three-dimensional femoral head penetration was 0.240 mm at 6 months, 0.230 mm at 1 year and 0.232 mm at 2 years. For both parameters, there was no measurable wear between 1 and 2 years, and the mean annual linear wear was less than 0.06 mm/year, which is less than the suggested osteolysis threshold for polyethylene. All patients demonstrated a dramatic improvement in clinical scores. These results were comparable with other studies that used alternative techniques with conventional radiography to evaluate wear for Marathon™. Long-term studies using the RSA method are recommended to further quantify the clinical performance of this polyethylene liner.

Rainbow trout (Oncorhynchus mykiss) were exposed to waste crankcase oil, a recognized source of polycyclic aromatic hydrocarbon (PAH) contamination in urban runoff. Dietary exposure was to a mean concentration of 0, 3.5, 8.9, and 13 {micro}g oil/g fish, and sampling took place after 3, 7, 11, and 15 weeks. The accumulation of compounds in muscle tissue, the elimination of bile metabolites, the activity of 7-ethoxyresorufin O-deethylase (EROD) in liver, and morphometric variables were compared at the different concentrations and times of sampling. The concentration of fluorescing compounds in muscle displayed the best dose- and time-response pattern, whereas other biological, chemical, and biochemical responses were not as well defined. No correlation could be drawn between the concentration of PAH in the oil and the measured variables. The environmentally relevant concentrations used in the experiment show the importance of choosing broad and specific indicators of exposure in a multidisciplinary investigation and the need for further research in chemical and toxicologic areas.

The Orthopaedic Unit of the Repatriation General Hospital (RGH) in Adelaide, South Australia has implemented a quality care management system for patients with arthritis of the hip and knee. The system not only optimises conservative management but ensures that joint replacement surgery is undertaken in an appropriate and timely manner. This new service model addresses identified barriers to service access and provides a comprehensive, coordinated strategy for patient management. Over 4 years the model has reduced waiting times for initial outpatient assessment from 8 to 3 months and surgery from 18 to 8 months, while decreasing length of stay from 6.3 to 5.3 days for hips and 5.8 to 5.3 days for knees. The service reforms have been accompanied by positive feedback from patients and referring general practitioners in relation to the improved coordination of care and enhanced efficiency in service delivery. What is known about the topic? Several important initiatives both overseas and within Australia have contributed significantly to the development of this model of care. These include the UK National Health Service ‘18 weeks’ Project, the Western Canada Waiting List Project, the New Zealand priority criteria project, the Queensland Health Orthopaedic Physiotherapy Screening Clinic, and most importantly the Melbourne Health–University of Melbourne Orthopaedic Waiting List Project where a wide range of models were explored across Victorian hospitals from 2005 and the Multi-Attribute Prioritisation Tool (MAPT) was developed, validated and tested. This project became the Osteoarthritis Hip and Knee Service (OAHKS) and was operationalised in the Victorian healthcare system from 2012. These initiatives examined and addressed various aspects of management systems for patients with arthritis of the hip and knee in their particular setting. What does this paper add? The development of this system is an extension of what is already known and is the first to encompass a comprehensive and coordinated strategy across all stages of the care management pathway for this patient group. Their management extends from the initial referral to development and implementation of a management plan, including surgery if assessed as necessary and organisation of long-term post operative follow up as required. By detailing the elements, key processes and measurable outcomes of the service redesign this paper provides a model for other institutions to implement a similar initiative. What are the implications for practitioners? An important aspect of the design process was practitioner acceptance and engagement and the ability to improve their capacity to deliver services within an efficient and effective model. Intrinsic to the model’s development was assessment of practitioner satisfaction. Data obtained including practitioner surveys indicated an increased level of both satisfaction with the redesigned management service, and confidence in it to deliver its intended improvements.

Background The Southern Adelaide Local Health Network is serviced by one orthopaedic surgeon specialising in foot and ankle surgery. In 2011, the waiting list to see the surgeon was expanding and the need for assistance was growing. The Department of Podiatry agreed to provide a podiatrist to assist in the management of the outpatient waiting list. Although patient outcome is an important outcome measure, we were interested in evaluating the service with respect to how satisfied patients were with seeing a podiatrist. Therefore, the primary aim of the study was to evaluate patient satisfaction with podiatry-led clinics for the orthopaedic outpatient waiting list. Secondary outcomes included discharge rate and efficiency of care. Methods We prospectively recruited a consecutive sample discharged from the Department of Podiatry between 1 May and 1 November 2013 to complete the Client Satisfaction Survey (CSQ-8). This survey was used to evaluate the satisfaction of patients following discharge from the Department of Podiatry. Results There were 49 patients (16 men, 33 women) enrolled in the survey during the 6-month period. Of the 49 patients discharged, 21 (43%) were discharged from the outpatient waiting list. Twenty-eight patients (57%) were referred on to the Department of Orthopaedic Surgery for opinion and management. The mean (± s.d.) number of appointments for each patient was 1.3 ± 0.6. Overall, patients were very satisfied with the assessment and/or treatment they received. Conclusion A podiatrist, working at an extended scope of practice and in collaboration with an orthopaedic surgeon, can successfully and efficiently assess and treat patients on an orthopaedic outpatient waiting list. Patients generally reported a high level of satisfaction with the process and would return to the clinic again if necessary. Hospital networks wanting to efficiently reduce waiting lists may endorse task substitution for appropriately skilled podiatrists. What is known about the topic? Allied health professionals have acted in extended scope of practice roles across several professions. These roles are often implemented in response to long waiting lists to see medical specialists. The acceptance of these practitioners by patients and the efficiency of these clinics are yet to be formally evaluated. What does the paper add? This paper should provide confidence in implementing orthopaedic triaging roles for podiatrists. High satisfaction rates were noted, along with an efficient service, both of which may be attractive for hospital networks. What are the implications for practitioners? Extended scope of practice podiatry roles may be implemented to assist in managing orthopaedic outpatient waiting lists.

A prospective cohort of 30 patients undergoing primary total hip arthroplasty for treatment of osteoarthritis was enrolled in a study to characterize the migration behavior of a clinically successf ...