Objectives. The clinical utility of routine cross sectional imaging of the
abdomen and pelvis in the screening and
To detect early signs of infection infrared thermography has been suggested to provide quantitative information. Our vision is to invent a pin site infection thermographic
Introduction and Objective. Digital infra-red thermography may have the capability of identifying local inflammations. Nevertheless, the role of thermography in diagnosing pin site infection has not been explored yet and the reliability and validity of this method for pin site
Purpose. This study was to investigate the effect of posterior tibial slope (PTS) on the kinematics in the cruciate-retaining total knee arthroplasty (CR-TKA) using 2- to 3- dimensional registration technique. Material & Methods. A total of 75 knees in 58 patients were recruited and categorized into the following two groups according to PTS. Group A was categorized PTS under 7degrees (n = 33) and group B was categorized PTS over 7 degrees (n = 42). The average age of group A and group B at the time of fluoroscopic
We hypothesized that using the navigation system, intra-operative knee kinematics after implantation measured may predict that post-operative kinematic in activities of daily living. Our aim was to compare intra-operative knee kinematics by a computed tomography (CT)-based navigation system and post-operative by the 2- to 3-dimensional registration techniques (2D3D). This study were performed for 8 patients (10 knees, medial osteoarthritis) who underwent primary PS TKA using CT-based navigation system. The median follow-up period from operation date to fluoroscopic
Summary. 162 patient cohort with serial Metal Artefact Reduction Sequence MRI scans. Patients with normal initial scans can be followed up at 1 year. Those with abnormal scans should be followed up at a shorter interval of 6 months. Introduction. Cross-sectional imaging is a key investigation in the assessment and
Our aim was to investigate whether it is possible to predict post-operative kinematics (Post-Ope) from intra-operative kinematics (Intra-Ope) after total knee arthroplasty. Our study were performed for 11 patients (14 knees) who underwent primary PS TKA using CT-based navigation system between Sept.2012 and Sept.2014. The mean subject age was 71.5 ± 5.5 years at the time of surgery. Intra-Ope was measured using the navigation system after implantation during passive full extension and flexion imposed by the surgeon. Under fluoroscopic
Summary. The effect of the geometry of the tibial polyethylene insert was investigated in vivo loaded conditions. Introduction. The decision to choose CR (cruciate retaining) insert or CS (condylar stabilised) insert during TKA remains a controversial issue. Triathlon CS type has a condylar stabilised insert with an increased anterior lip that can be used in cases where the PCL is sacrificed but a PS insert is not used. The difference of the knee kinematics between CR and CS insert remains unclear. This study measured knee kinematics of deep knee flexion under load in two insert designs using 2D/3D registration technique. Patients and Methods. We investigated the in vivo knee kinematics of 20 knees (18 patients) implanted with Triathlon CR components (Stryker Orthopedics, Mahwah, NJ), 10 knees in the CR insert with retaining PCL, and 10 knees in the CS insert with sacrificing PCL. All TKAs were judged clinically successful (Knee Society knee scores >90), with no ligamentous laxity or pain. Mean patient age at the time of operation was 72±12 years in CR and 69±9 years in CS. Mean period between operation and
There has been evidence of association between femoral shaft fractures and prolonged bisphosphonate therapy. We present a case series of bisphosphonate-associated fractures and invaluable lessons we have learnt. Over the last three years at our unit we have collected a case series of eight patients who have had atypical femoral fractures whilst on bisphosphonate therapy. We present illustrative cases, a summary of key findings, and invaluable lessons we have learnt. There was a long period of prodromal pain for two years before incomplete fractures developed. We speculate this is a warning sign of impending fracture. This may have been prevented with screening. Between incomplete fracture and complete fracture there was a short window of one month. Five patients presented with complete fracture, and three with thigh pain +/- evidence of incomplete fracture. Of the latter group all but one went on to develop complete fractures. The one patient who did not progress died six years after diagnosis. Of those five patients who presented with initial complete fracture, three patients recall thigh pain before fracture on further questioning. Despite being diaphyseal femoral fractures, there is a higher risk of neck of femur fractures in this patient cohort (both patients with initial interlocked nails subsequently developed neck of femur fractures soon after and were revised to cephalomedullary nails). Excluding one death from unrelated cause, only one patient has signs of complete fracture healing. All other patients are still receiving follow-up (mean 490 days). Three patients reported bilateral symptoms (pain). Two had had bilateral symptoms for one year. Both had visible incomplete fractures on further radiographic scrutiny; one underwent prophylactic cephalomedullary nailing, one was managed with active
Total knee replacements (TKR) have been the main choice of treatment for alleviating pain and restoring physical function in advanced degenerative osteoarthritis of the knee. Recently, there has been a rising interest in minimally invasive surgery TKR (MIS-TKR). However, accurate restoration of the knee axis presents a great challenge. Patient-specific-instrumented TKR (PSI-TKR) was thus developed to address the issue. However, the efficacy of this new approach has yet to be determined. The purpose of the current study was thus to measure and compare the 3D kinematics of the MIS-TKR and PSI-TKR in vivo during sit-to-stand using a 3D fluoroscopy technology. Five patients each with MIS-TKR and PSI-TKR participated in the current study with informed written consent. Each subject performed quiet standing to define their own neutral positions and then sit-to-stand while under the
The purpose of this study is to investigate the three-dimensional (3D) kinematics of normal knees in deep knee-bending motions like squatting and kneeling. Material & Methods: We investigated the in vivo kinematics of 4 Japanese healthy male volunteers (8 normal knees in squatting, 7 normal knees in kneeling). Each sequential motion was performed under fluoroscopic
There are several component position and design variables that increase the risk of edge loading and high wear in metal-on-metal hip resurfacing (MOM-HR). In this study we combined all of these variables to calculate the ‘contact patch to rim distance’ (CPRD) in patients undergoing revision of their MOM-HR. We then determined whether CPRD was more strongly correlated with component wear and blood metal ion levels, when compared to any other commonly reported clinical variable. This was a retrospective study of 168 consecutively collected MOM-HR retrieval cases. All relevant clinical data was documented, including pre-revision whole blood cobalt and chromium ion levels. Wear of the bearing surfaces was then measured using a roundness-measuring machine. We found four variables to be significantly (p < 0.05) correlated with component wear and blood metal ion levels: (1) cup inclination angle, (2) cup version angle, (3) arc of cover, and (4) CPRD. The correlations between CPRD and both wear and ion levels were significantly stronger than those seen with any other variable (all p < 0.0001). Our study has shown that CPRD is the best predictor of component wear and blood metal ion levels, and may therefore be a useful parameter to help determine those patients who are at risk of high wear and require more frequent clinical
Introduction of new implants has been widely debated lately, mainly in response to the problems surrounding hip resurfacing and one company recalling its product. Medicines and Healthcare products Regulatory Agency (MHRA) also issued advice about the management and monitoring of patients implanted with metal-on-metal articulations. In response to MHRA advice all the patients who underwent hip resurfacing in our hospital were assessed by two consultants according to MHRA guidelines. Here we present the findings from our District General Hospital. Between November 2006 and March 2009 we performed 42 hip resurfacings in 39 patients. Nearly all the procedures were performed by a single surgeon (39 out of 42). There were 27 males (28 hips) and 12 females (14 hips). Mean age of the patients at the time of surgery was 55.6 years (age range 40–67 years). Patients were followed up for a mean of 49 months (range 33–66 months). 27 patients (28 hips) were asymptomatic at the time of last follow up. Serum cobalt and chromium ion levels were measured in 21 patients (24 hips). Both the ion levels were within the recommended levels in 20 patients and over the recommended limit in 2 patients (one with bilateral hip resurfacing). MRI was diagnostic in 2 out of 5 patients. 5 patients (7 hips) were revised (one hip for neck resorption, 4 hips in 3 patients with lesions on MRI, 1 patient with bilateral hips for elevated serum ion levels). Considering the revision rate (7 hips out of 42 hips, 16%), we do believe that the review of the hip resurfacings in spite of the controversies surrounding the diagnostic criteria is necessary. This group of patients need to have continued
Total hip replacement (THR) is an option in a subset of patients with a neck of femur (NOF) fracture. The Scottish Intercollegiate Guidelines Network (SIGN) and National Institute for Clinical Excellence (NICE) provide guidance on the use of THR in patients with a NOF fracture. We compare our experience and recommend changes at a local level to allow successful implementation of the guideline to improve patient care. From July 2008 to July 2011, 36 THRs preformed for trauma were identified retrospectively by cross-referencing several databases (Bluespier, Worcestershire, UK and
Summary Statement. CXCR4 gene and protein expression is regulated in a dose and time-dependent manner by metallic wear debris but not polyethylene wear debris in vitro and in vivo. Introduction. Progressive osteolysis leading to aseptic loosening among metal-on-metal (MoM) total hip arthroplasties (THA's), and adverse reactions to metallic debris (ARMD) are increasing causes for concern among existing patients who have been implanted with MoM hip replacements. Close
Instruments used in surgery which rotate or vibrate at a high frequency can produce potentially contaminated aerosols. Such tools are in use in cemented hip revision arthroplasties. We aimed to measure the extent of the environmental and body contamination caused by an ultrasound device and a high-speed cutter. On a human cadaver we carried out a complete surgical procedure including draping and simulated blood flow contaminated with Staphylococcus aureus (ATCC 12600). After cemented total hip arthroplasty, we undertook repeated extractions of cement using either an ultrasound device or a high-speed cutter.
The biological significance of cobalt-chromium wear particles from metal-on-metal hip replacements may be different to the effects of the constituent metal ions in solution. Bacteria may be able to discriminate between particulate and ionic forms of these metals because of a transmembrane nickel/cobalt-permease. It is not known whether wear particles are bacteriocidal. We compared the doubling time of coagulase negative staphylococcus, Doubling time halved in metal-on-metal (p = 0.003) and metal-on-polyethylene (p = 0.131) particulate debris compared with the control. Bacterial nickel/cobalt-transporters allow metal ions but not wear particles to cross bacterial membranes. This may be useful for testing the biological characteristics of different wear debris. This experiment also shows that metal-on-metal hip wear debris is not bacteriocidal.