Introduction

A subset of patients in cast awaiting fixation of ankle fractures require conversion to delayed external fixation (dEF). We aimed to evaluate the effect of delayed versus planned external fixation (pEF), then identify objective characteristics contributing to need for conversion.

Variations in pelvic anatomy are a major risk factor for misplaced percutaneous sacroiliac screws used to treat unstable posterior pelvic ring injuries. A better understanding of pelvic morphology improves preoperative planning and therefore minimises the risk of malpositioned screws, neurological or vascular injuries, failed fixation or malreduction. Hence a classification system which identifies the clinically important anatomical variations of the sacrum would improve communication among pelvic surgeons and inform treatment strategy.

300 Pelvic CT scans from skeletally mature trauma patients that did not have pre-existing posterior pelvic pathology were identified. Axial and coronal transosseous corridor widths at both S1 and S2 were recorded. Additionally, the S1 lateral mass angle were also calculated. Pelvises were classified based upon the sacroiliac joint (SIJ) height using the midpoint of the anterior cortex of L5 as a reference point. Four distinct types could be identified:

Differences in transosseous corridor widths and lateral mass angles between classification types were assessed using two-way ANOVAs.

Type-B was the most common pelvic type followed by Type-A, Type-C, and Type-D. Significant differences in the axial and coronal corridors was observed for all pelvic types at each level. Lateral mass angles increased from Types-A to C, but were smaller in Type-D.

This classification system offers a guide to surgeons navigating variable pelvic anatomy and understanding how it is associated with the differences in transosseous sacral corridors. It can assist surgeons’ preoperative planning of screw position, choice of fixation or the need for technological assistance.

Total knee replacement (TKR) design aims to restore normal kinematics with emphasis on flexion range. The survivorship of a TKR is dependent on the kinematics in six-degrees-of-freedom (6-DoF). Stepping up, such as stair ascent is a kinematically demanding activity after TKR. The debate about design choice has not yet been informed by 6-DoF in vivo kinematics. This prospective randomised controlled trial (RCT) compared kneeling kinematics in three TKR designs.

68 participants were randomised to receive either cruciate retaining (CR-FB), rotating platform (CR-RP) or posterior stabilised (PS-FB) prostheses. Image quality was sufficient for 49 of these patients to be included in the final analysis following a minimum 1-year follow-up. Patients completed a step-up task while being imaged using single-plane fluoroscopy. Femoral and tibial computer-aided design (CAD) models for each of the TKR designs were registered to the fluoroscopic images using bespoke software OrthoVis to generate six-degree-of-freedom kinematics. Differences in kinematics between designs were compared as a function of flexion.

There were no differences in terminal extension between the groups. The CR-FB was further posterior and the CR-RP was more externally rotated at terminal extension compared to the other designs. Furthermore, the CR-FB designs was more posteriorly positioned at each flexion angle compared to both other designs. Additionally, the CR-RP design had more external femoral rotation throughout flexion when compared with both fixed bearing designs. However, there were no differences in total rotation for either step-up or down. Visually, it appears there was substantial variability between participants in each group, indicating unique patient-specific movement patterns.

While use of a specific implant design does influence some kinematic parameters, the overall patterns are similar. Furthermore, there is high variability indicating patient-specific kinematic patterns. At a group level, none of these designs appear to provide markedly different step-up kinematic patterns. This is important for patient expectations following surgery. Future work should aim to better understand the unique patient variability.

Dysmorphic pelves are a known risk factor for malpositioned iliosacral screws. Improved understanding of pelvic morphology will minimise the risk of screw misplacement, neurovascular injuries and failed fixation. Existing classifications for sacral anatomy are complex and impractical for clinical use. We propose a CT-based classification using variations in pelvic anatomy to predict the availability of transosseous corridors across the sacrum. The classification aims to refine surgical planning which may reduce the risk of surgical complications.

The authors postulated 4 types of pelves. The “superior most point of the sacroiliac joint” (sSIJ) typically corresponds with the mid-lower half of the L5 vertebral body. Hence, “the anterior cortex of L5” (L5_a) was divided to reference 3 distinct pelvic groups. A 4^th group is required to represent pelves with a lumbosacral transitional vertebra. The proposed classification:

Specific measures such as the width of the S1 and S2 axial and coronal corridors and the S1 lateral mass angles were used to differentiate between pelvic types.

Three-hundred pelvic CT scans were classified into their respective types. Analysis of the specific measures mentioned above illustrated the significant difference between each pelvic type. Changes in the size of S1 and S2 axial corridors formed a pattern that was unique for each pelvic type. The intra- and inter-observer ratings were 0.97 and 0.95 respectively.

Distinct relationships between the sizes of S1 and S2 axial corridors informed our recommendations on trans-sacral or iliosacral fixation, number and orientation of screws for each pelvic type. This classification utilises variations in the posterior pelvic ring to offer a planning guide for the insertion of iliosacral screws.

Prosthetic joint infections (PJI) are one of the most devastating complications of joint replacement surgery. They are associated with significant patient morbidity and carry a significant economic cost to treat. The management of PJI varies from antibiotic suppression, debridement, antibiotics, and implant retention (DAIR) procedures through to single/multiple stage revision procedures. Concerns have been raised recently in relation to the rising number of revision arthroplasty procedures that are being undertaken in relation to infection. This database aims to collect data on all PJIs that have been managed in the Australian Capital Territory (ACT) region. This will allow us to investigate the microbial trends, outcomes of surgical intervention and patient outcomes within our local population.

This database will incorporate diagnostic, demographic, microbiological and treatment information in relation to local PJI cases. The data will be collated from the local infectious diseases database, hospital medical records, and where available the Australian Orthopaedic Association National Joint Replacement Registry Data.

The first 100 cases of PJI were assessed. 76% were defined as being acute. 56% of the patients received antibiotics prior to their diagnosis however only 3% were culture negative. 89% were monomicrobial and 11% polymicrobial. The intended management strategy was a DAIR in 38% of patients and a 2-stage revision in 12% of cases. The intended management strategy was successful in 46% of the patients.

The ACT is uniquely placed to analyze and create a local PJI database. This will allow us to guide further treatment and local guidelines in terms of management of these complex patients.

The role of dual consultant operating (DCO) in general orthopaedics has not been researched; where it has shown benefit in other specialties, there is a lack of information on how DCO affects the surgeons themselves. We wanted to explore the potential effects of DCO on stress, as a foundation for further research to guide support for our surgeons.

We conducted a survey among orthopaedic consultants around New Zealand, containing questions pertaining to the demographics of respondents, their experience with DCO, what the expected risks and benefits of DCO would be, and provided two high-stress exemplar clinical scenarios where respondents were asked to rate their expected stress level at baseline, with a more junior consultant present, and with a more senior consultant present.

We found 99% of respondents had been involved in DCO at some point in their careers, yet only 38% were involved in DCO on at least a monthly basis. Perceived benefits greatly outweighed potential risks: 95% felt DCO would decrease their stress, 91% felt it improved intraoperative decision making, and 89% felt it provided more enjoyment at work and enhanced collegiality. A decrease in perceived stress was seen from baseline with a more junior consultant available and a greater decrease in stress seen with a more senior consultant, particularly in a complex elective setting.

All respondents felt there is benefit in DCO and the vast majority feel it has positive effects on stress levels. In a time where burnout is more prevalent, using tools such as DCO could be an effective way to decrease stress, enhance enjoyment and collegiality — challenging some key contributors to burnout — and support mentorship with further skill acquisition. This research provides a good base to pursue further qualitative and quantitative research into the area, with a view to addressing barriers to provision of regular DCO.

Aboriginal and Torres Strait Islander (ATSI) people have higher elective wait times compared to non-ATSI population in Australia. The Murrumbidgee Local Health District (MLHD) in southern New South Wales services 125,242km² and a population of 287,000 people, with 5.8% identifying as ATSI. The aim of this study is to investigate the arthroplasty waitlist time of ATSI, and the impact of rurality on joint replacement, within the MLHD and compared to the Australian national data.

1435 consecutive patients who underwent elective hip or knee arthroplasty from July 2018 to June 2021 were collated. Demographics, ATSI status, total wait time, readiness for care, and rurality were collected. Rurality was measured by distance from the arthroplasty hospital within MLHD. 1,151 patients were included after excluding patients with missing data or underwent emergent surgery.

Within this cohort, 72 of 1,151 patients (6.2%) identified as ATSI. ATSI were younger than non-ATSI population (60.7y v 66.4y). There was no difference between Aboriginal status and ready for care wait time (368.0 v 349.9 days; p=0.116). The rurality of the groups was similar and increasing rurality did not affect total wait time (ATSI 103.1km v 98.6km; p=0.309). There was no difference in total or not-ready-for-care time between the groups (p: 0.68).

Findings suggest equitable access to joint arthroplasty in the MLHD between ATSI and non-ATSI populations, which differs from the national experience. There is no significant difference between rurality and accessibility in the MLHD. This may be a result of the increased focus to ATSI and rural health within the district. A state or national study would be beneficial in identifying high performing regions and reviewing processes that enable equitable and accessible care.

MLHD provides equitable access to arthroplasty surgery between ATSI and non-ATSI, as well as patients from rural areas within the LHD.

Introduction

The use modular total hip arthroplasty is associated with potentially serious local and systemic complications. Each modular interface introduces a source for wear particle generation. Research suggests the etiology of wear particle generation and subsequent corrosion begins with mechanical fretting and disruption of the protective oxide layer leading to release of metal ions at the taper interface. The purpose of this study was to conduct three dimensional (3D) surface scans of the mating surfaces of the neck-stem taper to identify features that may contribute to the fretting and surface corrosion.

Background

The purpose of this study was to investigate the stability of dual-taper modular hip implants following impaction forces delivered in varying directions as measured by the distraction forces required to disassemble the components.

Introduction

Modularity in total hip arthroplasty offers many potential benefits, however the consequences of mechanically associated corrosion continue to be concerning. Micromotion and settling of the modular components at the taper interface are thought to contribute to the etiology of this problem. The purpose of this study was to investigate the effect of hammer blows delivered in different directions on the force transmitted to the head-neck and neck-stem interface in modular hip implants.

Summary Statement

An MRI-derived subject-specific finite element model of a knee joint was loaded with subject-specific kinetic data to investigate stress and strain distribution in knee cartilage during the stance phase of gait in-vivo.

Summary

Anatomical variations in hip joint anatomy are associated with both the presence and location of tibiofemoral osteoarthritis (OA).

Routine postoperative radiographs following hip hemiarthroplasty are commonly undertaken despite it being suggested that they can cause delays to discharge, discomfort to patients and unnecessary radiation. Our study considered the necessity of these post-operative radiographs.

A retrospective search was conducted of all hemiarthroplasty procedures on the Royal Cornwall Hospital database. These were reviewed for cases where re-operation was conducted within 6 weeks. Notes and post-operative check radiographs of those who underwent re-operation were reviewed to determine how essential radiographs were in diagnosing complications requiring re-operations.

A total of 1557 hemiarthroplasty operations were identified. There were 37 incidences of re-operation within 6 weeks. 29 cases had normal check radiographs. 8 dislocations were picked up on post-operative radiographs. In all but one of these cases, clinical suspicion of complication had been raised prior to the radiograph. In the remaining case documentation was poor and no firm conclusion as to clinical suspicion could be drawn.

Our review of over 1500 hemiarthroplasty cases, demonstrated one incident where the check radiograph solely diagnosed an abnormality needing intervention that might not have been apparent clinically. We thus suggest that check radiographs following hip hemiarthroplasty should not be routinely ordered for all patients.

The question of whether to reconstruct an ACL-deficient knee as early as possible following injury or to delay surgery remains unanswered. Early reconstruction potentially reduces the risk of secondary damage. However, there is also concern regarding the risk of arthrofibrosis if surgery is undertaken too soon. The aim of this study was to investigate whether injury-to-surgery delay determines ACL-reconstruction outcomes at up to 2years post-operatively.

A retrospective analysis of prospectively collected data from 211 knees with isolated primary ACL ruptures was performed. Patients were examined preoperatively, at 6months, 1 year, and 2 years post-operatively using International Knee Documentation Committee (IKDC) and Lysholm scores. Side to side differences in knee laxity were also measured with a KT1000 arthrometer. Spearman's rho correlations were used to associate injury-to-surgery delay with outcome scores.

Outcomes scores significantly increased for both IKDC (p<0.05) and Lysholm (p<0.05) questionnaires. Significant positive correlations (p<0.05) were also found between injury-to-surgery delay and IKDC and Lysholm subjective scores. Strongest correlation coefficients were noted at the 2yr follow-up for both IKDC and Lysholm scores (r = 0.79 and 0.8 respectively). Side-to-side laxity measures also showed significant positive correlations with injury-to-surgery delay at 1 year (r = 0.17) and 2 year (r = 0.41) follow ups. The positive correlation suggests that delayed surgery is positively related to subjective outcomes, as well as objective measures of knee laxity.

However, this relationship also suggests that other factors such as the patient's functional status at time of surgery may play a role in their post-operative function. For example, those who can compensate for the ruptured ligament may function well following delayed surgery. These findings highlight the need for more detailed investigation of the interaction between functional status, injury-to-surgery delay and post-operative recovery.

An ACL reconstruction is designed to restore the normal knee function and prevent the onset and progression of degenerative changes such as osteoarthritis. However, contemporary literature provides limited consensus on whether knee degeneration can be attenuated by the reconstruction procedure. The aim of this pilot study was to identify the presence of early osteoarthritis after ACL reconstruction using MRI analysis.

19 patients who had undergone an ACL reconstruction (9 isolated ACL rupture, 8 ACL rupture and meniscectomy, 2 ACL rupture and meniscal repair) volunteered for this study. MRI's were collected preoperatively and postoperatively for analysis with a mean follow up of 23 months. The Boston-Leeds Osteoarthritis Knee Score (BLOKS) was used for the analysis of the articular cartilage by a consultant orthopaedic surgeon. Scores ranged from 0–3, with 0 being total coverage and thickness of the cartilage and 3 being no coverage. Qualitative analysis was then conducted on each patient to determine if the articular cartilage improved, degenerated, or did not change between preoperative and follow-up scans.

All patients with isolated ACL rupture were found to either have no change or improved articular cartilage scores in their follow up scans compared preoperatively. In contrast, patients with a meniscal repair displayed worse cartilage scores postoperatively. Lastly, of the patients who had an associated meniscectomy, 6 had worse follow-up results, with the remaining patients showing no change or improved cartilage scores.

The present results indicate that patients with an isolated ACL rupture have a reduced risk of developing OA compared to those with associated meniscal injuries. This has implications for analysing the outcome of current ACL reconstruction techniques and in predicting the likelihood of patients developing OA after ACL reconstruction. Future work will involve confirming this pattern in a larger patient sample, as well as exploring additional factors such as time to surgery delay and rehabilitation strategy.