Aims

A substantial fraction of patients undergoing knee arthroplasty (KA) or hip arthroplasty (HA) do not achieve an improvement as high as the minimal clinically important difference (MCID), i.e. do not achieve a meaningful improvement. Using three patient-reported outcome measures (PROMs), our aim was: 1) to assess machine learning (ML), the simple pre-surgery PROM score, and logistic-regression (LR)-derived performance in their prediction of whether patients undergoing HA or KA achieve an improvement as high or higher than a calculated MCID; and 2) to test whether ML is able to outperform LR or pre-surgery PROM scores in predictive performance.

Introduction. In total knee arthroplasty, the aim is to relieve pain and provide a stable, functional knee. Sagittal stability is crucial in enabling a patient to return to functional activities. Knee implants with a medial pivot (MP) design are thought to more accurately reproduce the mechanics of the native joint, and potentially confer greater antero-posterior stability through the range of flexion than some other implant designs. Aim. This study aims to compare the sagittal stability of four different total knee arthroplasty implant designs. Method. Comparison was made between four different implant designs: medial pivot (MP), two different types of cruciate retaining (CR1 and CR 2) and deep dish (DD). A cohort of 30 Medial Pivot (MP) knees were compared with matched patients from each of the other designs, 10 in each group. Patients were matched for age, body mass index and time to follow up. Clinical examination was carried out by an orthopaedic surgeon blinded to implant type, and sagittal stability was tested using a KT1000 knee arthrometer, applying 67N of force at 30˚ and 90˚. Results. The MP knee was more stable than the CR1 knee at both 30º (mean movement: 1.37mm vs 2.48mm, p=0.037) and 90º (1.68mm vs 2.37mm, p=0.030). The MP knee was more stable than the CR2 knee at 30º (0.98mm vs1.33mm, p=0.013). The MP knee also demonstrated less movement at 90 º (0.98mm vs 1.33mm), but this was not statistically significant (p=0.156). The MP knee was more stable than the DD knee at 30 º (0.48mm vs 1.33mm, p=0.03) and 90 º (0.67mm vs 1.15mm, p=0.048). Overall the medial pivot design was more stable than all non-medial pivot designs at 30 º (0.8mm vs1.66mm, p=0.003) and 90 º (1.1mm vs 1.61mm, p= 0.008). Conclusion. Overall, the medial pivot design demonstrated significantly greater antero-posterior stability than all other design types included in this study. Correlation with patient reported outcome scales will allow insight into whether these statistically significant differences are also clinically significant

Aims

The aim of this study was to investigate the distribution of phenotypes in Asian patients with end-stage osteoarthritis (OA) and assess whether the phenotype affected the clinical outcome and survival of mechanically aligned total knee arthroplasty (TKA). We also compared the survival of the group in which the phenotype unintentionally remained unchanged with those in which it was corrected to neutral.

Aims

This is a multicentre, prospective assessment of a proportion of the overall orthopaedic trauma caseload of the UK. It investigates theatre capacity, cancellations, and time to surgery in a group of hospitals that is representative of the wider population. It identifies barriers to effective practice and will inform system improvements.

Aims

BoneMaster is a thin electrochemically applied hydroxyapatite (HA) coating for orthopaedic implants that is quickly resorbed during osseointegration. Early stabilization is a surrogacy marker of good survival of femoral stems. The hypothesis of this study was that a BoneMaster coating yields a fast early and lasting fixation of stems.

Introduction. Although weight-bearing CT of the foot definitely reflects the morphology and deformity of joint, it is hard to obtain the standing CT due to difficulty of availability. Although 3D imaging reconstruction using radiographs has been reported in other joints, there is no study about foot joint. The purpose of this study is to develop a semi-automatic method based on a deformable surface fitting for achieving the weight-bearing 3D model reconstruction from standing radiographs for foot. Methods. Our method is based on a Laplacian surface deformation framework using a template model of foot. As pre- processing step, we obtained template surface meshes having the average shapes of foot bones (talus, calcaneus) from standing CT images (Planmed Verity) in 10 normal volunteers. In the reconstruction step, the surface meshes are deformed following guided user inputs with geometric constraints to recover the target shapes of 30 patients while preserving average bone shape and smoothness. Finally, we compared reconstructed 3D model to original standing CT images. Analysis was performed using Dice coefficients, average shape distance, maximal shape distance. Results. The obtained reconstruction model is close to the actual standing foot geometry (Dice coefficients 0.89, average shape distance 0.88 mm, maximum shape distance 6.33 mm). We present the accuracy and robustness of our method via comparison between the reconstructed 3D models and the original bone surfaces. Conclusions. Weight-bearing 3D foot model reconstruction from standing radiographs is concise and the effective method for analysis of foot joint alignment and deformity

Aims

We aimed to compare the implant survival, complications, readmissions, and mortality of Vancouver B2 periprosthetic femoral fractures (PFFs) treated with internal fixation with that of B1 PFFs treated with internal fixation and B2 fractures treated with revision arthroplasty.

Aims

Time to treatment initiation (TTI) is generally defined as the time from the histological diagnosis of malignancy to the initiation of first definitive treatment. There is no consensus on the impact of TTI on the overall survival in patients with a soft-tissue sarcoma. The purpose of this study was to determine if an increased TTI is associated with overall survival in patients with a soft-tissue sarcoma, and to identify the factors associated with a prolonged TTI.

Aims

Malreduction of the syndesmosis has been reported in up to 52% of patients after fixation of ankle fractures. Multiple radiological parameters are used to define malreduction; there has been limited investigation of the accuracy of these measurements in differentiating malreduction from inherent anatomical asymmetry. The purpose of this study was to identify the prevalence of positive malreduction standards within the syndesmosis of native, uninjured ankles.

We aimed to determine whether the EBRA method had greater precision and sensitivity for measuring implant migration following total hip arthroplasty (THA) than direct plain radiographic techniques using modern measuring tools. Short-term precision was evaluated in 20 subjects following THA. Consecutive, standardised radiographs of the hip were performed on the same day after repositioning. Prosthetic cup and stem migration were measured from the plain radiographs using a digital calliper following methods described by Ianotti, Malchau, Nunn, Sutherland and Wetherall, and compared to those made using EBRA. Precision was expressed as 95% confidence interval (95%CI = 1.96x Std.dev.). 10 subjects were then followed prospectively with standardised plain radiographs at baseline, 6,12 and 26 weeks after THA. Migration measurements made using EBRA were compared to those made using the most precise plain radiographic method. The 95%CI of all EBRA cup and stem measurements was ±1mm or smaller. Only the Sutherland method had a similar level of precision (95%CI ±1.11 to 1.28 mm: F-Test P> 0.05; all other method comparisons with EBRA P< 0.05). In the longitudinal study cup cranial migration of 0.53 mm (SEM 0.19) and stem subsidence of 1.53 mm (SEM 0.19) were detected using EBRA (2-way ANOVA by rank; P< 0.05 and P< 0.001 respectively). No statistically significant migration of the cup or stem was detected using the Sutherland method. The EBRA method is a precise method for describing implant migration in small groups of patients in the early period following THA, and manual methods lack sufficient precision to be used for this purpose

Aims

Functional rehabilitation has become an increasingly popular treatment for Achilles tendon rupture (ATR), providing comparably low re-rupture rates to surgery, while avoiding risks of surgical complications. Limited evidence exists on whether gap size should affect patient selection for this treatment option. The aim of this study was to assess if size of gap between ruptured tendon ends affects patient-reported outcome following ATR treated with functional rehabilitation.

Aims

The use of frozen tumour-bearing autograft combined with a vascularized fibular graft (VFG) represents a new technique for biological reconstruction of massive bone defect. We have compared the clinical outcomes between this technique and Capanna reconstruction.

Introduction. Total hip arthroplasty (THA) is a commonly performed surgical procedure for the treatment of hip arthritis. Approximately 50,000 THAs are performed annually in Canada. The costs incurred to the healthcare system are tremendous, amounting to anywhere between 4.3 and 7.3 billion dollars each year. Despite the substantial financial burden of THA to the Canadian healthcare system, few studies have provided accurate cost estimations of this procedure. Purpose. To determine the impact of surgical approach on costs of THA from a hospital perspective, and provide an updated cost estimation of THA within a publically funded healthcare system. Methods. We recruited patients undergoing a THA through an anterior, posterior, or lateral approach for study participation. A single surgeon was designated to perform every case using the surgical approach of their expertise. Each patient received standardized implants: a collared, hydroxyapatite-coated, cementless femoral stem (Corail TM stem, DePuy Orthopaedics Inc., Warsaw, IN), a cementless acetabular cup (Pinnacle Sector II TM acetabular cup, DePuy Orthopaedics Inc., Warsaw, IN), a highly cross-linked polyethylene liner (AltrX TM polyethylene liner, DePuy Orthopaedics Inc., Warsaw, IN), and a cobalt chrome femoral head (Articul/eze TMcobalt chrome, DePuy Orthopaedics Inc., Warsaw, IN). We prospectively recorded costs of operating room time, length of stay in hospital, and medical and surgical interventions using a micro-costing method. Group comparisons were performed using Pearson's Chi-square and one-way Analysis of Variance (ANOVA), with post-hoc testing when necessary. All costs were reported in 2013 Canadian dollars. Results. One-hundred and eighteen patients (40 anterior, 38 posterior, and 40 lateral) completed the study. All three groups were similar with regards to age (p=0.79), sex (p=0.97), and body mass index (p=0.54). Mean operating room time was significantly shorter for the lateral (49.0 minutes, 95%CI 46.5 – 51.5) versus anterior (69.3 minutes, 95%CI 66.0 – 72.6, p<0.001) and posterior approach (61.6 minutes, 95%CI 57.5 – 65.5, p<0.001). Mean length of stay was shorter for the anterior (33.9 hours, 95%CI 29.6 – 38.2) compared to the posterior (65.8 hours, 95%CI 56.8 – 74.8, p<0.001) and lateral approach (64.2 hours, 95%CI 56.7 – 71.7, p<0.001). The operating room costs were significantly higher for the anterior versus posterior (p=0.008) and lateral approach (p<0.001, figure 1). The total inpatient costs were significantly for the anterior versus posterior and lateral approach (p<0.001 for both pair-wise comparisons, figure 2). Total costs were significantly less for the anterior ($7300.22, 95%CI 7064.49 – 7535.95) versus posterior ($8287.46, 95%CI 7906.41 – 8668.51, p<0.001) and lateral approach ($7853.10, 95%CI 7577.29 – 8128.91, p=0.031). Discussion / Conclusion. Total costs for THA were significantly less when performed using an anterior approach. A reduction in hospital length of stay contributed significantly to an overall reduction in costs from a hospital perspective. Future analyses will determine the cost-effectiveness of the anterior approach from both a hospital and societal perspective

Aims

The aim of this study was to determine the risk of local recurrence and survival in patients with osteosarcoma based on the proximity of the tumour to the major vessels.

Objective. Sarcomas are a rare group of tumours, which pose numerous problems regarding correct diagnosis and appropriate management. This study aimed to examine whether symptom duration and tumour size at diagnosis have changed over time, using size and symptom duration as methods of comparison. Methods. All patients diagnosed with sarcoma were identified retrospectively from a prospective database from 1963 to 2005. Demographic data concerning age at diagnosis, sex and diagnosis were recorded. Data were also collected on duration of symptoms and size of tumour at diagnosis. Symptom duration is defined as the length of time the patient was experiencing symptoms for until the date of diagnosis. Changes in size and symptom duration over time were compared by grouping date of diagnosis into time periods and comparing them against each other using non-parametric statistical analysis. Results. 4560 met our inclusion and exclusion criteria, with 2492 Bone Sarcomas (BS) and 2068 Soft Tissue Sarcomas (STS). Overall analysis of both BS and STS showed that size at diagnosis has decreased and symptom duration has increased. Analysis of STS showed that size has decreased over time, particularly following the introduction of referral guidelines in 1999 (median size pre 99 = 10cm, post = 8cm, Mann-Whitney-U test p=0.000 to 3 sig. fig.), but symptom duration has remained unaltered over time. Duration of symptoms reported for BS has significantly increased over time; however, size at diagnosis has remained unchanged over time. Conclusions. It appears from this study that STS are being diagnosed more quickly and that this is most likely due to the introduction of specific STS guidelines in 1999. This result is particularly heartening, and should encourage further promotion of such guidelines. Awareness of BS still appears to be low as size at diagnosis remains unchanged over time

Seventy-one Geomedic total knee replacements were reviewed retrospectively at a maximum of eight and a half years. The prosthesis was found to be successful in its primary aim of relieving pain. However, there was an overall failure rate of 18.3%. Analysis of the results by an actuarial method allowed comparison with other prostheses. The factors involved in failure are discussed

Introduction: Obtaining adequate images can be difficult in ring fixator patients during outpatient follow-up. Following a recent publication, we introduced the spirit level technique as an effective method to ensure better quality images for interpretation, reduce unnecessary x-ray exposure, and improve clinic efficiency. Method: A comparison was made of radiograph quality, patient inconvenience and x-ray exposure between standard X-ray techniques and those with a frame mounted spirit-level in all patients attending the senior author’s outpatient clinic for routine follow up following Ilizarov and Taylor-Spatial frames. Prospective data was collected using a paper proforma in frame clinic. Information was gathered on all patients sent for plain radiographs. Radiographers collected data regarding time taken in the X-ray Department and total number of radiographs taken to gain the images required. The senior author recorded if these images were satisfactory and if returned to the department for further imaging. The radiation dose was retrieved from the Radiology computer. The control group consisted of patients from clinics prior to implementation of the spirit-level device. Following a period of familiarization, data was collected from the study group using the spirit-level. Results: (Table deleted). Conclusion: The implementation of a simple frame mounted spirit-level as a guide for the radiographers in the outpatient clinic improves x ray quality, to assess healing, and significantly reduces the number of suboptimal images. The data does not support a significant impact on patient inconvenience

Whole blood metal ion levels remain a concern in those patients undergoing total hip replacement with metal bearing surfaces. The determination of baseline reference levels are essential if useful information can be gleaned from in vivo studies of functioning implants. We set out to prospectively determine chromium and cobalt metal ion concentrations in patients undergoing total hip replacement to determine reference levels of these metal ions. 100 patients with normal renal function, no occupational or environmental exposure to cobalt and chromium, and an absence of implanted metals were recruited into the study. Metal ion levels were determined using two different assay methods. Both ICP-MS (Inductively Coupled Plasma Mass Spectroscopy) and GFAAS (Graphite Furnace Atomic Adsorption Spectroscopy) are well recognized analytical techniques for the quantification of trace elements. Levels were correlated with gender, age and place of residence. There was considerable variability in whole blood metal ion levels, with the ICPMS being more sensitive and consistent than the GFAAS method. Direct comparison of concentration levels determined by the two methods revealed no significant correlation. There was no correlation with age, gender and place of residence. Our findings would favour the use of the ICP-MS to determine reference levels and as a baseline for metal ion surveillance pre-operatively in patients undergoing metal-on-metal total hip replacements. We also determined that changes in whole blood metal ion levels are more significant than actual levels in patients who have undergone total hip replacement

Whole blood metal ion levels remain a concern in those patients undergoing total hip replacement with metal bearing surfaces. The determination of baseline reference levels are essential if useful information can be gleaned from in vivo studies of functioning implants. We set out to prospectively determine chromium and cobalt metal ion concentrations in patients undergoing total hip replacement to determine reference levels of these metal ions. 100 patients with normal renal function, no occupational or environmental exposure to cobalt and chromium, and an absence of implanted metals were recruited into the study. Metal ion levels were determined using two different assay methods. Both ICP-MS (Inductively Coupled Plasma Mass Spectroscopy) and GFAAS (Graphite Furnace Atomic Adsorption Spectroscopy) are well recognised analytical techniques for the quantification of trace elements. Levels were correlated with gender, age and place of residence. There was considerable variability in whole blood metal ion levels, with the ICP-MS being more sensitive and consistent than the GFAAS method. Direct comparison of concentration levels determined by the two methods revealed no significant correlation. There was no correlation with age, gender and place of residence. Our findings would favour the use of the ICP-MS to determine reference levels and as a baseline for metalion surveillance pre-operatively in patients undergoing metal-on-metal total hip replacements. We also determined that changes in whole blood metal ion levels are more significant than actual levels in patients who have undergone total hip replacement

Objectives

Meropenem may be an important drug in the treatment of open tibial fractures and chronic osteomyelitis. Therefore, the objective of this study was to describe meropenem pharmacokinetics in plasma, subcutaneous adipose tissue (SCT), and cancellous bone using microdialysis in a porcine model.