A staging system has been developed to revise the 1994 ARCO classification for ONFH. The final consensus resulted in the following 4-staged system: stage I—X-ray is normal, but either magnetic resonance imaging or bone scan is positive; stage II—X-ray is abnormal (subtle signs of osteosclerosis, focal osteoporosis, or cystic change in the femoral head) but without any evidence of subchondral fracture, fracture in the necrotic portion, or flattening of the femoral head; stage III—fracture in the subchondral or necrotic zone as seen on X-ray or computed tomography scans. This stage is further divided into stage IIIA (early, femoral head depression ≤2 mm) and stage IIIB (late, femoral head depression >2 mm); and stage IV—X-ray evidence of osteoarthritis with accompanying joint space narrowing, acetabular changes, and/or joint destruction. Radiographs, magnetic resonance imaging (MRI), and computed tomography (CT) scans may all be involved in diagnosing ONFH; however, the optimal diagnostic modality remains unclear. The purpose of this study was to identify: 1) how ONFH is diagnosed at a single academic medical center, and 2) if CT is a necessary modality for diagnosing/staging OFNH. The EMR was queried for the diagnosis of ONFH between 1/1/2008–12/31/2018 at a single academic medical center. CT and MRI scans were reviewed by the senior author and other contributors. The timing and staging quality of the diagnosis of ONFH were compared between MRI and CT to determine if CT was a necessary component of the ONFH work-up.Introduction
Methods
Despite the positive outcomes in shoulder joint replacements in the last two decades, polyethylene wear debris in metal-on-polyethylene artificial shoulder joints is well-known as a limitation in the long-term survival of shoulder arthroplasties systems. Consequently, there is an interest in the use of novel materials as an alternative to hard bearing surfaces such as pyrolytic carbon layer (PyroCarbon). In the present study, the unique Newcastle Shoulder Wear Simulator was used (Smith A physiological combined cycled “Repeat-motion-load” (RML) (Ramirez-Martinez Introduction
Materials and Methods
Total hip replacement with metal-on-polymer (MoP) hip prostheses is a successful treatment for late-stage osteoarthritis. However, the wear debris generated from the polymer acetabular liners remains a problem as it can be associated with osteolysis and aseptic loosening of the implant. This has led to the investigation of more wear resistant polymers in orthopaedics. Cross-linked polyethylene (XLPE) is now the gold-standard acetabular liner material. However, we asked if carbon fibre reinforced polyether ether ketone (CFR-PEEK) might be a lower wear material. In addition, we sought to understand the influence of contact stress on the wear of both XLPE and CFR-PEEK as this has not previously been reported. A 50-station circularly translating pin-on-disc (SuperCTPOD) machine was used to wear test both XLPE and CFR-PEEK pins against cobalt chromium (CoCr) discs to investigate the influence of contact stress on their wear rates. Fifty XLPE and 50 CFR-PEEK pins were articulated against CoCr discs. The pins, 9 mm in outer diameter and 12 mm in height, were drilled with different diameter holes to generate different sized annuli and thus, different contact areas. The pins were tested at 1.10, 1.38, 1.61, 2.00 and 5.30 MPa, which are typical contact stresses observed in the natural hip joint. An additional pin for every test group was used as a control to track the lubricant uptake. The discs were polished to 0.015 μm Sa prior to testing. The test stations contained 16 ml of diluted newborn calf serum (protein concentration: 22 g/L). Wear was measured gravimetrically with a balance (resolution: 10 μm) every 500,000 cycles. A standardised cleaning and weighing protocol was followed.Introduction
Materials and Methods
Shoulder joint prostheses have become the most commonly replaced after knee and hip artificial implants. Reverse shoulder arthroplasty (RSA) is the treatment option for patients with severe osteoarthritis, rotator cuff arthropathy or a massive rotator cuff tear with pseudoparalysis. Though successful, the long-term survival of such implants are limited by wear of the materials in contact [1, 2]. The aim of this study was to investigate RSA wear Four new JRI Orthopaedics Reverse Shoulder 42 mm diameter VAIOS with cobalt-chromium (CoCr) glenospheres and ultra-high molecular weight polyethylene (UHMWPE) humeral components were tested. A five million cycles wear test was undertaken using the unique Newcastle Shoulder Wear Simulator with dilute bovine serum as a lubricant. “Mug to mouth” was performed as the ADL to the test prostheses in intervals of 100 cycles, following by 5 seconds of high load (450N) with no motion simulating an ADL such as “lifting an object”. This combined load cycle was then repeated. A fifth reverse shoulder prosthesis was subject to dynamic loading only in a soak control station. Wear was assessed gravimetrically and roughness (Sa) of the articulating surfaces was measured with a non-contacting profilometer.INTRODUCTION
MATERIALS AND METHODS
Metal-on-polyethylene (MoP) is the most commonly used bearing couple in total hip replacements (THRs). Retrieval studies (Cooper A 6-station anatomical hip joint simulator was used to investigate material loss at the articulating and taper-trunnion surfaces of 32mm diameter metal-on-cross-linked polyethylene (MoXLPE) joints for 5 million cycles (Mc) with a sixth joint serving as a dynamically loaded soak control. Commercially available cobalt-chromium-molybdenum (CoCrMo) femoral heads articulating against XLPE acetabular liners (7.5Mrad) were used with a diluted new-born-calf-serum lubricant. Each CoCrMo femoral head was mounted on a 12/14 titanium alloy trunnion. The test was stopped every 0.5Mc, components were cleaned and gravimetric measurements performed following ISO 14242-2 and the lubricant was changed. Weight loss (mg) obtained from gravimetric measurements was converted into volume loss (mm3) and wear rates were calculated from the slopes of the linear regression lines in the volumetric loss versus number of cycles plot for heads, liners and trunnions. Additionally, volumetric measurements of the head tapers were obtained using a coordinate measuring machine (CMM) post-test. The surface roughness (Sa) of all heads and liners was measured pre and post-test. At the end of the test, the femoral heads were cut and the roughness of the worn and unworn area was measured. Statistical analysis was performed using a paired-t-test (for roughness measurements) and an independent sample t-test (for wear rates).Introduction
Methods
The bearing surfaces of ceramic-on-ceramic (CoC) total hip replacements (THR) show a substantially lower wear rate than metal-on-polyethylene (MoP) THR Three 36mm CoC hips were tested in a hip simulator for 5 million cycles (Mc). BIOLOX®delta ceramic femoral heads were mounted on 12/14 titanium (Ti6Al4V) trunnions. Wear of femoral heads, acetabular liners and trunnions was determined gravimetrically using the analytical balance. Roughness measurements (Sa) were taken on the articulating surfaces (pre and post-test) and on the trunnion surfaces (worn and unworn). Furthermore, Energy Dispersive X-ray Spectroscopy (EDX) was used to identify and quantify the wear debris present in the lubricant using scanning electron microscope (SEM).Introduction
Methods
Wear of polymeric glenoid components has been identified as a cause of loosening and failure of shoulder implants1,2 in vivo. A small number of shoulder joint simulators have been built for in vitro wear testing, however none have been capable of testing with physiological motion patterns in three axes and with physiological loading. The Newcastle Shoulder Wear Simulator was designed with three axes of motion, which are programmable so that different activities of daily living might be replicated. The simulator uses three pneumatic cylinders with integral position encoders to move five shoulder prostheses simultaneously in the flexion-extension, abduction-adduction, and internal-external rotation axes. Axial loading is applied with pneumatic cylinders supplied from a pneumatic proportional valve via a manifold, which also supplies a sixth static control station. In order to establish if that the machine can actually perform as intended, commissioning trials were conducted replicating lifting a 0.5 Kg weight to head height as a daily living activity. During the commissioning trials JRI Orthopaedics Reverse VAIOS shoulder prostheses were tested in 50% bovine serum at ambient temperature. The results show that the shoulder joint wear simulator can satisfactorily reproduce a daily living activity deliberately selected for having a large range of motion and loading. Other daily activities, such as drinking from a mug, are less demanding in the ranges of motion and loading and represent no difficulty in being reproduced on the simulator. Now successfully commissioned, this new multi-station shoulder wear simulator can wear test current and new designs of shoulder prosthesis in vitro
Back pain is a common orthopaedic problem which results in hospital admissions in severe cases. The aim of our study was to identify the reasons for back pain admissions and role of further investigations in the treatment of severe back pain. We collected data prospectively for all admissions between January and March 2011. Demographic details were recorded along with the reasons for admissions, time of admission, further investigations and treatment offered.Background
Methods
Nerve Root compression can lead to severe back pain. Different risk factors like high BMI, smoking, alcohol and psychological history have been identified. The aim of our study was to identify if the incidence of these risk factors was higher in patients with nerve root compression. We collected data prospectively for 26 consecutive patients admitted between January and March 2011 with severe back pain and had an MRI scan. Demographic details were recorded along with occupation, BMI, smoking status, alcohol intake and psychological history. 12 patients had nerve root compression (Group A) on MRI scan and 14 had normal MRI scan (Group B).Background
Patients and methods
Management of compound fractures, which have a higher infection risk than closed fractures, currently depends on surgeon training and past practice rather than evidence based practice. Some centres use delayed closure involving a second surgery with repeat debridement and wound closure 48 hours after initial debridement and fixation. Other centres use primary closure in the absence of gross contamination or major soft tissue deficits, where debridement, fixation and wound closure occur during the initial surgery. Delayed closure was used at our centre until January 2009 when the standard of care evolved to primary closure where appropriate. Primary closure allows more efficient OR utilization due to fewer OR visits, but it is unknown if primary closure increases the risk of infection, which can, in turn, lead to fracture non-union. The purpose of this pilot study was to complete a safety analysis of infection rates in the first 40 patients undergoing primary closure of a compound fracture; enrolment is ongoing and updated results will be presented. Patients admitted in 2010 with a long bone(femur, tibia/fibula, humerus, radius/ulna) Gustilo grade I-IIIA compound fracture, without the following: gross organic contamination, compartment or crush syndrome, amputation, or gunshot wound, were eligible for primary closure at fracture fixation, and thus for study inclusion. The analysis compared primary closure subjects with matched delayed closure subjects taken from a previous prospective cohort study of >700 subjects. Subjects were matched at a one:two ratio(i.e. one primary closure:two delayed closure patients) on fracture location, Gustilo grade of fracture, age(within five years), significant comorbidities(diabetes, kidney disease and osteoporosis) and social factors(smoking and alcohol abuse). The outcomes were 1) any infection and 2) deep infection within six weeks of surgery. Time on antibiotics and length of hospital stay(LOS) was also recorded.Purpose
Method
This study aims to investigate femoral blood flow during Metal-on-Metal Hip Resurfacing (MMHR) by monitoring oxygen concentration during the operative procedure. Patients undergoing MMHR using the posterior approach were evaluated. Following division of fascia lata, a calibrated gas-measuring electrode was inserted into the femoral neck, aiming for the supero-lateral quadrant of the head. Baseline oxygen concentration levels were detected after electrode insertion 2-3cm below the femoral head surface and all intra-operative measures were referenced against these. Oxygen levels were continuously monitored throughout the operation. Data from ten patients are presented. Oxygen concentration dropped most noticeably during the surgical approach and was reduced by 62% (Std.dev +/-26%) following dislocation and capsulectomy. Insertion of implants resulted in a further oxygenation decrease by 18% (Std.dev +/-28%). The last obtained measure before wound closure detected 22% (Std.dev +/-31%) of initial baseline oxygen levels. Variation between subjects was observed and three patients demonstrated a limited recovery of oxygen levels during implant insertion and hip relocation. Intra-operative measurement of oxygen concentration in blood perfusing the femoral head is feasible. Results in ten patients undergoing MMHR showed a dramatic effect on the oxygenation in the femoral head during surgical approach and implant fixation. This may increase the risk of avascular necrosis and subsequent femoral neck fracture. Future experiments will determine if less invasive procedures or specific positioning of the limb can protect the blood supply to femoral neck and head.
Cancer is a major health problem for teenagers and young adults (TYA’s). However, many young people are often late to receive a cancer diagnosis. Young people may not recognize symptoms as serious and delay seeking help. Furthermore, there is evidence to suggest that once a young person does seek help from a general practitioner (GP), significant delay can still occur. During the annual Find Your Sense of Tumour (FYSOT) conference 2007; a group of 200 TYA’s with cancer participated in a survey regarding their diagnostic experience; the cohort included 22 patients with bone tumours. Following the onset of symptoms; nearly half of the TYA’s with a bone tumour (46%) reported 4 or more visits to their G.P before being referred to a specialist. However, 91% of bone tumour patients had multiple, ‘classic’ cancer symptoms and the majority (77%) sought help from the G.P within 4 weeks of noticing symptoms. The ‘Christie Crew’ (CC) are a group of TYA’s who have been treated for cancer and work on various projects to improve cancer services. The Christie Crew wanted to empower young people with the knowledge that TYA’s do get cancer and to raise awareness of the signs and symptoms of cancer and have produced a DVD and education pack that has been launched across 80 schools and throughout the North West. The DVD is highlights individual’s stories of diagnosis. There is also a poster campaign highlighting signs and symptoms of cancer being displayed in large public venues across the Manchester area. The aim is to roll out the project nationally as part of the health awareness (Healthy Schools) initiative. By highlighting that young people get cancer it is hoped that more young people will recognise the signs and symptoms and be empowered to go to their GP if they have persistent problems.
Parker et al examined the effect that delay to surgery has on patients with proximal femoral fractures. They found that a delay of more than 48 hours to surgery significantly increased the patient’s length of stay. They examined delays due to lack of theatre resource only. Therefore an audit was proposed at the RUH Bath to set a standard of care that fracture neck of femur patients should be operated on within 48 hours. One month of data was collected (August 2005) and analysed. Of 52 fracture neck of femur patients 23% were waiting longer than 48 hours. The recommendation was made to have extra lists made available for fracture neck of femur patients. In January 2006 the elective orthopaedic ward was closed (for 12 days) due to diarrhoea and vomiting. Therefore elective lists were utilised for trauma. The audit was repeated comparing these 12 days with 12 in December. In the December cohort seven neck of femur fracture patients waited more than 48 hours, in the January cohort no neck of femur patient waited more than 48 hours. A further recommendation was made for increased theatre capacity for neck of femur patients. Subsequent to these recommendations 2 half day fracture neck of femur lists have been added to the rota at the RUH Bath. (Tuesday and Thursday pm). The patients can be assessed and worked up as planned trauma and can be seen in advance by the anaesthetist. Audit of January 2007 fractured neck of femur patients showed that there were 46 patients treated with only 1 waiting more than 48 hours due to theatre capacity. In conclusion the audit process can work and achieve beneficial results as shown here. An accepted standard of care was taken from the literature, department performance analysed, changes implemented and closure of the audit loop has shown that it has worked.
