This paper describes the methodology, validation and reliability
of a new computer-assisted method which uses models of the patient’s
bones and the components to measure their migration and polyethylene
wear from radiographs after total hip arthroplasty (THA). Models of the patient’s acetabular and femoral component obtained
from the manufacturer and models of the patient’s pelvis and femur
built from a single computed tomography (CT) scan, are used by a
computer program to measure the migration of the components and
the penetration of the femoral head from anteroposterior and lateral radiographs
taken at follow-up visits. The program simulates the radiographic
setup and matches the position and orientation of the models to
outlines of the pelvis, the acetabular and femoral component, and
femur on radiographs. Changes in position and orientation reflect
the migration of the components and the penetration of the femoral
head. Validation was performed using radiographs of phantoms simulating
known migration and penetration, and the clinical feasibility of
measuring migration was assessed in two patients.Aims
Materials and Methods
As patient data continues to grow, the importance of efficient and precise
The use of routine sampling for histological
Gait
Primary hip and knee joint replacements in Canada have been estimated to cost over $1.4 billion dollars annually, with revision surgery costing $177 million. The most common cause of revision arthroplasty surgery in Canada is infection. Periprosthetic joint infections (PJIs) are a devastating though preventable complication following arthroplasty. Though variably used, antibiotic laden bone cement (ALBC) has been demonstrated to decrease PJIs following primary total knee arthroplasty (TKA). Unfortunately, ALBC is costlier than regular bone cement (RBC). Therefore, the aim of this study was to determine if the routine use of ALBC in primary TKA surgery is a cost-effective practice from the perspective of the Canadian healthcare system. A decision tree was constructed using a decision
For many years, marker-based systems have been used for motion
Non-linear methods in statistical shape
Abstract. Background. Oxidized zirconium (OxZr) has been introduced as an alternative bearing for femoral components in Total Knee Arthroplasty (TKA). It has a ceramic-like zirconium oxide outer layer with a low coefficient of friction. Early studies have found OxZr TKA to have a low incidence of early failure in young high demand patients. Currently no study has reported on the outcome of these implants beyond ten years. Objectives. The purpose of our study was to present an in-depth 15-year survival
Dual mobility (DM) total hip replacements (THRs) were introduced to reduce dislocation risk, which is the most common cause of early revision. Although DM THRs have shown good overall survivorship and low dislocation rates, the mechanisms which describe how these bearings function in-vivo are not fully understood. Therefore, the study aim was to comprehensively assess retrieved DM polyethylene liners for signs of damage using visual inspection and semi-quantitative geometric assessment methods. Retrieved DM liners (n=18) were visually inspected for the presence of surface damage, whereby the internal and external surfaces were independently assigned a score of one (present) or zero (not present) for seven damage modes. The severity of damage was not assessed. The material composition of embedded debris was characterised using energy-dispersive x-ray
Aims. The conventionally described mechanism of distal biceps tendon rupture (DBTR) is of a ‘considerable extension force suddenly applied to a resisting, actively flexed forearm’. This has been commonly paraphrased as an ‘eccentric contracture to a flexed elbow’. Both definitions have been frequently used in the literature with little objective
Dual Mobility (DM) Total Hip Replacements (THRs) were introduced to reduce dislocation risk, which is the most common cause of early revision. The in-vivo mechanics of these implants is not well understood, despite their increased use in both elective and trauma settings. Therefore, the aim of this study was to comprehensively assess retrieved DM polyethylene liners for signs of damage using visual inspection and semi-quantitative geometric assessment techniques. Retrieved DM liners (n=20) were visually inspected for the presence of seven established modes of polyethylene damage. If embedded debris was identified on the external surface, its material composition was characterised using energy-dispersive x-ray
Progressive collapsing foot deformity (PCFD) is a common condition with an estimated prevalence of 3.3% in women greater than 40 years. Progressive in nature, symptomatic flatfoot deformity can be a debilitating condition due to pain and limited physical function; it has been shown to have one of the poorest preoperative patient reported outcome scores in foot and ankle pathologies, second to ankle arthritis. Operative reconstruction of PCFD can be performed in a single-stage manner or through multiple stages. The purpose of this study is to compare costs for non-staged (NS) flatfoot reconstructions, which typically require longer hospital stays, with costs for staged (S) reconstructions, where patients usually do not require hospital admission. To our knowledge, the comparison between single-staged and multi-staged flatfoot reconstructions has not been previously done. This study will run in conjunction with one that compares rates of complications and reoperation, as well as patient reported outcomes on function and pain associated with S and NS flatfoot reconstruction. Overall, the goal is to optimize surgical management of PCFD, by addressing healthcare costs and patient outcomes. At our academic centre with foot and ankle specialists, we selected one surgeon who primarily performs NS flatfoot reconstruction and another who primarily performs S procedures. Retrospective chart reviews of patients who have undergone either S or NS flatfoot reconstruction were performed from November 2011 to August 2021. Length of operating time, number of primary surgeries, length of hospital admission, and number of reoperations were recorded. Cost
Aims. Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common orthopaedic procedures requiring postoperative radiographs to confirm implant positioning and identify complications. Artificial intelligence (AI)-based image
The aim of this study was to assess the incidence the microbiological spectrum and clinical outcome of hip and knee revision arthroplasties with unexpected-positive-intraoperative-cultures (UPIC) at a single center with minimum follow up of 2 years. We retrospectively analyzed our prospectively maintained institutional arthroplasty registry. Between 2011 and 2020 we performed presumably aseptic rTHA (n=939) and rTKA (n= 1,058). Clinical outcome, re-revision rates and causes as well as the microbiological spectrum were evaluated.Aims
Methods
Introduction. The PACE trial was the first randomized controlled trial (RCT) investigating the efficacy of paracetamol in acute low back pain. Non-compliance to study medication was considered to be a limitation of this RCT. In contrast to conventional statistical methods, complier average causal effects (CACE)
Introduction. The accuracy of hexapod circular external fixator deformity correction is contingent on the precision of radiographic
µCT images are commonly analysed to assess changes in bone density and architecture in preclinical murine models. Several platforms provide automated
Abstract. Objectives. While spinal fusion is known to be associated with adjacent disc degeneration, little is known on the role of the facet joints in the process, and whether their altered biomechanics following fusion plays a role in further spinal degeneration. This work aimed to develop a model and method to sequentially measure the effects of spinal fusion on lumbar facet joints through synchronisation of both motion
Aims. The standard of surgical treatment for lower limb neoplasms had been characterized by highly interventional techniques, leading to severe kinetic impairment of the patients and incidences of phantom pain. Rotationplasty had arisen as a potent limb salvage treatment option for young cancer patients with lower limb bone tumours, but its impact on the gait through comparative studies still remains unclear several years after the introduction of the procedure. The aim of this study is to assess the effect of rotationplasty on gait parameters measured by gait
Aims. The aim of this study was to present the first retrieval
Reduced cervical spine canal AP diameter is linked to the development of spinal cord injury and myelopathy. This is of particular interest to clinicians in New Zealand, given a unique socio-ethnic make-up and prevalent participation in collision sport. Our study builds upon previous unpublished evidence, by analysing normal cervical spine CT scans to explore morphological differences in the sub-axial cervical spine canal, between New Zealand European, Māori and Paciāca individuals. 670 sub-axial cervical vertebrae (C3-C7) were analysed radiographically using high resolution CT trauma scans, showing no acute pathology with respect to the cervical spine. All measurements were made uPlising mulP-planar reconstruction software to obtain slices parallel to the superior endplate at each vertebral level. Maximal canal diameter was measured in the AP and transverse planes. Statistical
Finite element
In 2020 almost 90% of femoral heads for total hip implants in Germany were made of ceramic. Nevertheless, the cellular interactions and abrasion mechanisms in vivo have not been fully understood until now. Metal transfer from the head-neck taper connection, occurring as smear or large-area deposit, negatively influences the surface quality of the articulating bearing. In order to prevent metal transfer, damage patterns of 40 Biolox delta ceramic retrievals with CoC and CoPE bearings were analysed. A classification of damage type and severity for each component (n=40) was done according to an established scoring system. To investigate the physical properties, the surface quality was measured using confocal microscopy, quantitative
Objectives. Understanding lumbar facet joint involvement and biomechanical changes post spinal fusion is limited. This study aimed to establish an in vitro model assessing mechanical effects of fusion on human lumbar facet joints, employing synchronized motion, pressure, and stiffness
Aims. The aim of this study was to evaluate the optimal deep tissue specimen sample number for histopathological
Introduction. Anterior cruciate ligament reconstruction (ACLr) is the most widely published operation in the orthopaedic literature. Over recent years there has been increased interest in the surgical technique and role of concomitant procedures performed during ACLr. The National Ligament Registry (NLR) collects robust data on ACLr performed in the UK. In this registry
Aims. To perform an incremental cost-utility
Aims. Impaired fracture repair in patients with type 2 diabetes mellitus (T2DM) is not fully understood. In this study, we aimed to characterize the local changes in gene expression (GE) associated with diabetic fracture. We used an unbiased approach to compare GE in the fracture callus of Zucker diabetic fatty (ZDF) rats relative to wild-type (WT) littermates at three weeks following femoral osteotomy. Methods. Zucker rats, WT and homozygous for leptin receptor mutation (ZDF), were fed a moderately high-fat diet to induce T2DM only in the ZDF animals. At ten weeks of age, open femoral fractures were simulated using a unilateral osteotomy stabilized with an external fixator. At three weeks post-surgery, the fractured femur from each animal was retrieved for
Aims. The metabolic variations between the cartilage of osteoarthritis (OA) and Kashin-Beck disease (KBD) remain largely unknown. Our study aimed to address this by conducting a comparative
Aims. To compare the cost-effectiveness of high-dose, dual-antibiotic cement versus single-antibiotic cement for the treatment of displaced intracapsular hip fractures in older adults. Methods. Using data from a multicentre randomized controlled trial (World Hip Trauma Evaluation 8 (WHiTE-8)) in the UK, a within-trial economic evaluation was conducted. Resource usage was measured over 120 days post randomization, and cost-effectiveness was reported in terms of incremental cost per quality-adjusted life year (QALY), gained from the UK NHS and personal social services (PSS) perspective in the base-case
For clinical movement
Aim. Multidisciplinary team (MDT) management of complex bone and joint infections (BJI) is increasingly implemented but studies evaluating this approach are scarce. We assessed the effectiveness of our MDT by analyzing the adherence to its treatment decisions. Method. A cohort study was conducted comprising patients with complex BJI of which the management was discussed during MDT meetings between 2015 and 2022 in a tertiary care academic hospital. Patient characteristics and MDT data were obtained from electronic patient records. Results. The
Pelvic tilt (PT) is always described as the pelvic orientation along the transverse axis, yet four PT definitions were established based on different radiographic landmarks: anterior pelvic plane (PT. a. ), the centres of femoral heads and sacral plate (PT. m. ), pelvic outlet (PT. h. ), and sacral slope (SS). These landmarks quantify a similar concept, yet understanding of their relationships is lacking. Some studies referred to the words “pelvic tilt” for horizontal comparisons, but their PT definitions might differ. There is a demand for understanding their correlations and differences for education and research purposes. This study recruited 105 sagittal pelvic radiographs (68 males and 37 females) from a single clinic awaiting their hip surgeries. Hip hardware and spine pathologies were examined for sub-group
Aims. The aim of this study was to compare the cost-effectiveness of cemented hemiarthroplasty (HA) versus hydroxyapatite-coated uncemented HA for the treatment of displaced intracapsular hip fractures in older adults. Methods. A within-trial economic evaluation was conducted based on data collected from the World Hip Trauma Evaluation 5 (WHiTE 5) multicentre randomized controlled trial in the UK. Resource use was measured over 12 months post-randomization using trial case report forms and participant-completed questionnaires. Cost-effectiveness was reported in terms of incremental cost per quality-adjusted life year (QALY) gained from the NHS and personal social service perspective. Methodological uncertainty was addressed using sensitivity
Abstract. Objective. Up to 20% of patients can remain dissatisfied following TKR. A proportion of TKRs will need early revision with aseptic loosening the most common. The ATTUNE TKR was introduced in 2011 as successor to its predicate design The PFC Sigma (DePuy Synthes, Warsaw, In). However, following reports of early failures of the tibial component there have been ongoing concerns of increased loosening rates with the ATTUNE TKR. In 2017 a redesigned tibial baseplate (S+) was introduced, which included cement pockets and an increased surface roughness to improve cement bonding. Given the concerns of early tibial loosening with the ATTUNE knee system, this study aimed to compare revision rates and those specific to aseptic loosening of the ATTUNE implant in comparison to an established predicate as well as other implant designs used in a high-volume arthroplasty centre. Methods. The Attune TKR was introduced to our unit in December 2011. Prior to this we routinely used a predicate design with an excellent long-term track record (PFC Sigma) which remains in use. In addition, other designs were available and used as per surgeon preference. Using a prospectively maintained database, we identified 10,202 patients who underwent primary cemented TKR at our institution between 01/04/2003–31/03/2022 with a minimum of 1 year follow-up (Mean 8.4years, range 1–20years): 1) 2406 with ATTUNE TKR (of which 557 were S+) 2) 4652 with PFC TKR 3) 3154 with other cemented designs. All implants were cemented using high viscosity cement. The primary outcome measures were all-cause revision, revision for aseptic loosening, and revision for tibial loosening. Kaplan-Meier survival analysis and Cox regression models were used to compare the primary outcomes between groups. Matched cohorts were selected from the ATTUNE subsets (original and S+) and PFC groups using the nearest neighbor method for radiographic
3D printing acetabular cups offers the theoretical advantage of enhanced bony fixation due to greater design control of the porous implant surfaces. Analysing retrieved 3D printed implants can help determine whether this design intent has been achieved. We sectioned 14 off-the-shelf retrieved acetabular cups for histological
X-Linked Hypophosphataemia (XLH) is a rare, progressive, hereditary phosphate-wasting disorder characterised by excessive activity of fibroblast growth factor 23. The International XLH Registry was established to provide information on the natural history of XLH and impact of treatment on patient outcomes. The cross-sectional orthopaedic data presented are from the first interim
Aims. The aim of this study is to report the implant survival and factors associated with revision of total elbow arthroplasty (TEA) using data from the Dutch national registry. Methods. All TEAs recorded in the Dutch national registry between 2014 and 2020 were included. The Kaplan-Meier method was used for survival
Aim. The aim of our study was to analyze putative genes for virulence factors of Cutibacterium isolates obtained from implant-associated infections. Methods. We analyzed 64 isolates of Cutibacterium spp. (C. acnes (53/64), C. avidum (6/64), C. granulosum (4/64), C. namnetense (1/64)) using NextSeq 550 (Illumina, San Diego, CA, USA) and performed genomic
Functional outcomes are important for patients with bone tumors undergoing lower extremity endoprosthetic reconstruction; however, there is limited empirical evidence evaluating function longitudinally. The objective of this study was to determine the changes in function over time in patients undergoing endoprosthetic reconstructions of the proximal femur, distal femur and proximal tibia. We conducted a secondary
Aims. The risk of mechanical failure of modular revision hip stems is frequently mentioned in the literature, but little is currently known about the actual clinical failure rates of this type of prosthesis. The current retrospective long-term
Aims. Insufficient treatment response in rheumatoid arthritis (RA) patients requires novel treatment strategies to halt disease progression. The potential benefit of combination of cytokine-inhibitors in RA is still unclear and needs further investigation. To explore the impact of combined deficiency of two major cytokines, namely interleukin (IL)-1 and IL-6, in this study double deficient mice for IL-1αβ and IL-6 were investigated in different tumour necrosis factor (TNF)-driven inflammatory bone disorders, namely peripheral arthritis and sacroiliitis, as well as systemic bone loss. Methods. Disease course, histopathological features of arthritis, and micro-CT (µCT) bone
The pathophysiological basis of alterations in trabecular bone of patients with osteonecrosis of the femoral head (ONFH) remains unclear. ONFH has classically been considered a vascular disease with secondary changes in the subchondral bone. However, there is increasing evidence suggesting that ONFH could be a bone disease, since alterations in the functionality of bone tissue distant from the necrotic lesion have been observed. We comparatively studied the transcriptomic profile of trabecular bone obtained from the intertrochanteric region of patients with ONFH without an obvious aetiological factor, and patients with osteoarthritis (OA) undergoing total hip replacement in our Institution. To explore the biological processes that could be affected by ONFH, we compared the transcriptomic profile of trabecular bone from the intertrochanteric region and the femoral head of patients affected by this condition. Differential gene expression was studied using an Affymetrix microarray platform. Transcriptome
Introduction. Pes cavovarus is a foot deformity that can be idiopathic (I-PC) or acquired secondary to other pathology. Charcot-Marie-Tooth disease (CMT) is the most common adult cause for acquired pes cavovarus deformity (CMT-PC). The foot morphology of these distinct patient groups has not been previously investigated. The aim of this study was to assess if morphological differences exist between CMT-PC, I-PC and normal feet (controls) using weightbearing computed tomography (WBCT). Methods. A retrospective
Distal interphalangeal joint (DIPJ) fusion using a k-wire has been the gold standard treatment for DIPJ arthritis. Recent studies have shown similar patient outcomes with the headless compression screws (HCS), however there has been no cost
Introduction. Anterior cruciate ligament (ACL) injuries are one of the most common knee injuries amongst elite athletes and usually require an ACL reconstruction (ACLR) to enable return to sport. Secondary surgery can result in a longer rehabilitation period and often a. significant time away from sport which can have implications to the athlete including contract obligations and sponsorship. Advances in ACLR techniques and meniscal repair techniques as well as an awareness of meniscal root lesions, ramp lesions and lateral extraarticular procedures (LEAPs) during ACL surgery has improved outcomes. The purpose of this study was to evaluate the rates of secondary surgery following the introduction of a systematic arthroscopic evaluation of the knee, improved meniscal repair techniques and the addition of a concomitant LEAP This systematic approach was introduced after October 2012 (10/2012). Methods. Professional athletes who underwent primary ACLR with a minimum follow-up of 2 years were identified from the (blinded for review). Those who had undergone major concomitant procedures such as multi-ligament reconstruction or osteotomy were excluded.
Aims. The aim of this study was to compare the cost-effectiveness of surgical fixation with Kirschner (K-)wire ersus moulded casting after manipulation of a fracture of the distal radius in an operating theatre setting. Methods. An economic evaluation was conducted based on data collected from the Distal Radius Acute Fracture Fixation Trial 2 (DRAFFT2) multicentre randomized controlled trial in the UK. Resource use was collected at three, six, and 12 months post-randomization using trial case report forms and participant-completed questionnaires. Cost-effectiveness was reported in terms of incremental cost per quality-adjusted life year (QALY) gained from an NHS and personal social services perspective. Sensitivity analyses were conducted to examine the robustness of cost-effectiveness estimates, and decision uncertainty was handled using confidence ellipses and cost-effectiveness acceptability curves. Results. In the base case
The Adams-Berger reconstruction is an effective technique for treating distal radioulnar joint (DRUJ) instability. Graft preparation techniques vary amongst surgeons with insufficient evidence to support one technique over another. Our study evaluated the biomechanical properties of four graft preparation techniques. Extensor tendons were harvested from fresh frozen porcine trotters obtained from a local butcher shop and prepared in one of three configurations (n=5 per group): tendon only; tendon prepared with non-locking, running suture (2-0 FiberLoop, Arthrex, Naples, FL) spaced at 6 mm intervals; and tendon prepared with suture spaced at 12 mm intervals. A fourth configuration of suture alone was also tested. Tendons were allocated in a manner to ensure comparable average diameters amongst groups. Biomechanical testing occurred using custom jigs simulating radial and ulnar tunnels attached to a Bose Electroforce 3510 mechanical testing machine (TA Instruments). After being woven through the jigs, all tendons were sutured end-to-end with 2-0 PROLENE suture (Ethicon). Tendons then underwent a staircase cyclic loading protocol (5-25 Newtons [N] at 1 hertz [Hz] for 1000 cycles, then 5-50 N at 1 Hz for 1000 cycles, then 5-75 N at 1 Hz for 1000 cycles) until graft failure; if samples did not fail during the protocol, they were then loaded to failure. Samples were visually inspected for mode of failure after the protocol. A one-way
Aim. Periprosthetic joint infections (PJI) and surgical site infections (SSI) are one of the most severe complications in joint arthroplasty. Decolonization measures prior to elective orthopedic surgeries have shown to reduce the risk of infection especially in patient identified as carriers of S. aureus. However additional screening measures can be difficult to implement in daily routine. The objective was to study the influence of universal decolonization with polihaxanid on SSI rates. Method. Between January 2017 and December 2018 patients scheduled for hip or knee joint arthroplasty in 5 participating orthopedic centers received polyhexanid containing decolonization set consisting of oral, nasal and wipes. Patients were instructed to perform a 5 day decolonization regimen 4 days prior to surgery. SSIs were recorded according to modified CDC criteria for a surveillance period of 90days after surgery. Results. During the study period, 4437 decolonization sets were distributed to patients. 1869 patients consented to participate in the study and provide detailed feedback on compatibility and compliance. Overall SSI rate was 0.87 per 100 surgeries prior to introduction of the decolonization, while it was 0.97 per 100 surgeries during the period of decolonization and 0.59 per 100 surgeries in those using the decolonization set. SSI rates due to Staphylococcus aureus were 0.32 per 100 surgeries, 0.21 per 100 surgeries and 0.05 per 100 surgeries respectively. In patients receiving an elective hip-joint arthroplasty SSI rate was 0.93 per 100 surgeries prior to introduction, while it was 1.17 per 100 surgeries during the intervention period and 0.96 per 100 surgeries in patients that used the decolonization set. However SSI rates due to Staphylococcus aureus were 0.30 per 100 surgeries, 0.14 per 100 surgeries and 0.10 per 100 surgeries respectively. In patients receiving, an elective knee-joint arthroplasty SSI rate was 0.52 per 100 surgeries prior to introduction, while it was 0.53 per 100 surgeries during the intervention period and 0.12 per 100 surgeries in patients that used the decolonization set. However, SSI rates due to Staphylococcus aureus were 0.20 per 100 surgeries, 0.13 per 100 surgeries and 0.00 per 100 surgeries respectively. In addition to these preliminary results, we will provide and present a further
Aims. Using data from the Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemiarthroplasty (HEALTH) trial, we sought to determine if a difference in functional outcomes exists between monopolar and bipolar hemiarthroplasty (HA). Methods. This study is a secondary