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Biomedical subjects

D E Beverland

Publications and source records attributed to D E Beverland.

At least 19 recordsLinked to original sources
PubMed2006

Intraoperative knee anthropometrics: correlation with cartilage wear.

Accurate knee morphology is of value in determining the correct sizing of prosthetic implants. Intraoperative measurement of key linear dimensional variables was carried out on 196 Caucasian knees (osteoarthritic patients: 68 male and 128 female). Of the 196 knees measured, 70 had extensive cartilage degeneration. Statistical analysis was carried out on this large sample size of data. Summary statistics and correlation coefficients between variables were determined and compared between subgroups. Male knees were on average larger than female knees. Higher correlation was found between variables for males than between variables for females. Overall, the patellar dimensions were seen to correlate least well with other anatomical variables. High correlation between femoral variables supports current femoral sizing procedure, although routine patellar resection practices are called into question. Average values for the 70 knees with extensive cartilage degeneration were significantly smaller (P < 0.01) than their counterparts for the other 126 knees. For a measurement not containing cartilage, such as femoral epicondylar width, this difference cannot be accounted for by the loss of cartilage owing to wear. This suggests that, for similar height and weight, a naturally narrower femoral epicondylar width may be associated with severe osteoarthritis.

Aged↗
PubMed2005

Comparison of gait kinematics in patients receiving minimally invasive and traditional hip replacement surgery: a prospective blinded study.

Minimally invasive (MI) total hip replacement (THR) supposedly provides improved ambulation in the immediate post-operative period. This study used a prospective blinded design to analyse early post-operative walking ability using gait analysis. Seventeen patients were available for full analysis with nine having had the MI technique and eight having the standard incision (SI) technique. Patients were blinded as to the incision used, as were all physiotherapists and assessors. Differences in temporal-spatial variables and joint kinematics measured 1 day pre-operatively, 2 days post-operatively and 42 days (6 weeks) post-operatively were compared between groups. There was no significant difference in velocity, step length of the affected or unaffected leg, stride length or stance phase duration between the MI and SI groups between any of the timepoints tested. There was no significant improvement in the gait kinematics of the MI group compared to the SI group either 2 days post-operatively or 6 weeks post-operatively. Contrary to previous studies, there was no improvement in early post-operative gait for those patients who received THR using the minimally invasive technique.

Arthroplasty, Replacement, Hip↗
PubMed2004

Assessment of cement introduction and pressurization techniques.

The objective of this study was to measure the medullary pressures generated during bone cement injection, pressurization and femoral prosthesis insertion. The measurements were recorded throughout the length of an in vitro femoral model while implanting a series of prosthetic hip stems using different pressurization techniques. The prostheses used were a Charnley 40 flanged stem (Johnson & Johnson DePuy International Limited), an Exeter No. 3 stem (Stryker Howmedica Osteonics, Howmedica International Limited), and a customized femoral component (Johnson & Johnson DePuy International Limited). The following parameters were derived from the pressure data recorded: peak pressure, decay pressure and duration above optimum pressure of 76 kPa to predict adequate penetration. The custom and Exeter stems generated cement pressures throughout the length of the cavity model that were predicted to achieve adequate bone cement interdigitation into cancellous bone. For all the conditions investigated in this study, when using the Charnley femoral component, an adequate level of cement pressurization was generated in the medial-distal portion of the femoral cavity. It is postulated that this could result in reduced integration of the cement mantle with bone and less effective transmission of functional loads applied during a patient's normal activity, postoperatively.

Arthroplasty, Replacement, Hip↗
PubMed2002

The influence of shape and sliding distance of femoral head movement loci on the wear of acetabular cups in total hip arthroplasty.

Wear of the polyethylene acetabular component is the most serious threat to the long-term success of total hip replacements (THRs). Greatly reduced wear rates have been reported for unidirectional, compared to multidirectional, articulation in vitro. This study considers the multidirectional motions experienced at the hip joint as described by movement loci of points on the femoral head for individual THR patients. A three-dimensional computer program determined the movement loci of selected points on the femoral head for THR patients and normal subjects using kinematic data obtained from gait analysis. The sizes and shapes of these loci were quantified by their sliding distances and aspect ratios with substantial differences exhibited between individual THR patients. The average sliding distances ranged from 10.0 to 18.1 mm and the average aspect ratios of the loci ranged from 2.5 to 9.2 for the THR patients. Positive correlations were found between wear rate and average sliding distance, the inverse of the average aspect ratio of the loci and the product of the average sliding distance and the inverse of the average aspect ratio of the loci. Patients with a normal hip joint range of motion produce multidirectional motion loci and tend to experience more wear than patients with more unidirectional motion loci. Differing patterns of multidirectional motion at the hip joint for individual THR patients may explain widely differing wear rates in vivo.

Acetabulum↗
PubMed2001

Total knee arthroplasty without patellar resurfacing in isolated patellofemoral osteoarthritis.

Thirty-one patients (33 knees) with symptomatic patellofemoral osteoarthritis and minimal tibiofemoral changes underwent LCS total knee arthroplasty without patellar resurfacing. Average age was 73 years (range, 58-89 years) with a female-to-male ratio of 5:1. Average follow-up was 20 months (range, 12-40 months). All except 4 patients had grade 3 or 4 patellofemoral osteoarthritis. Preoperatively, all patients had significant knee pain. Sleep disturbance was reported in 21 patients. All but 10 patients required walking aids. Average range of motion was 108 degrees (range, 80-125 degrees ). At latest review, 21 knees were pain-free, the remaining 12 knees being described as having only occasional knee pain. Two patients continued to have night pain. Average range of motion was 104 degrees (range, 70-135 degrees ). Lateral patellar tilt improved in all but 5 knees by an average of 7 degrees (range, 1-26 degrees ). Patellar congruency improved in all but 3 knees by an average of 18% (range, 3-63%). None of the patients to date have required revision surgery. Total knee arthroplasty without patellar resurfacing is an effective option in older patients with isolated patellofemoral osteoarthritis.

Aged↗
PubMed2001

Periprosthetic tibial fractures after cementless low contact stress total knee arthroplasty.

Periprosthetic fractures are a recognized complication of total knee arthroplasty. Fractures may occur intraoperatively or postoperatively, and risk factors have been identified that may predispose an individual to such a complication. We report 7 cases of periprosthetic tibial fractures after low contact stress total knee arthroplasty, a complication encountered by the senior author (D.E.B.) only after a change in practice from a cemented implant to a cementless one. In light of this previously unreported complication in our unit, we attempted to identify common features within this group of patients that may have contributed to fracture occurrence. Statistical analysis revealed a highly significant (P<.005) risk of periprosthetic tibial fracture in patients with a preoperative neutral or valgus knee. Age, gender, and diagnosis did not appear to increase the risk of fracture significantly. All patients displayed evidence of reduced bone mineral density in the lumbar spine and femoral neck regions on dual-energy x-ray absorptiometry scanning. Patients with a preoperative neutral or valgus knee and local evidence of osteopenia represent a high-risk group, in whom particular care in alignment should be taken. In this group, it may be preferable to have the tibial component inserted with cement fixation.

Aged↗
PubMed1993

Pressurization of bone cement under standard, flanged and custom acetabular components for total hip replacement.

Custom acetabular components are proposed to achieve uniform cement mantles, even in irregular acetabula presented at revision, in order to enhance fixation. One aim of developing custom components was to permit pressurization of bone cement by the components at insertion and maintain the pressure during polymerization. A model acetabulum was set up for the insertion of standard, flanged and custom components under constant force. Cement pressure was measured at the floor of the acetabulum by means of a piezoelectric diaphragm transducer. Polythene tubes were inserted in the model acetabular walls to estimate penetration of cement into cancellous bone. Insertion of the standard and flanged components caused cement pressures up to 106 kPa which decayed to less than 21 kPa as cement escaped at the rim and the components came into contact with the acetabulum. The custom component maintained a pressure of over 60 kPa during polymerization from an initial pressure of 105 kPa and examination of cement mantles on removal showed no evidence of contact. The custom component also showed enhanced penetration of cement, especially around the rim of the acetabulum. It is concluded that the custom component design achieves higher cement pressures and that better fixation will result.

Bone Cements↗
PubMed1992

Unnecessary arthroscopies.

A review of the results of arthroscopies on patients taken from an 'open access' service waiting list has been carried out. One-third of all arthroscopies proved to be negative. Accuracy of clinical diagnosis was not related to the clinical grade of the examining doctor. The excess annual cost to the Northern Ireland Orthopaedic Service of unnecessary arthroscopies may have been of the order of 89,000 pounds.

Arthroscopy↗
PubMed1992

Total joint replacement: implication of cancelled operations for hospital costs and waiting list management.

OBJECTIVE: To identify aspects of provision of total joint replacements which could be improved. DESIGN: 10 month prospective study of hospital admissions and hospital costs for patients whose total joint replacement was cancelled. SETTING: Information and Waiting List Unit, Musgrave Park Regional Orthopaedic Service, Belfast. PATIENTS: 284 consecutive patients called for admission for total joint replacement. MAIN MEASURES: Costs of cancellation of operation after admission in terms of hotel and opportunity costs. RESULTS: 28(10%) planned operations were cancelled, 27 of which were avoidable cancellations. Five replacement patients were substituted on the theatre list, leaving 22(8%) of 232 operating theatre opportunities unused. Patients seen at assessment clinics within two months before admission had a significantly higher operation rate than those admitted from a routine waiting list (224/232(97%) v 32/52(62%), x2 = 58.6, df = 1; p < 0.005). Mean duration of hospital stay in 28 patients with cancelled operations was 1.92 days. Operating theatre opportunity costs were 73% of the total costs of cancelled total joint replacements. CONCLUSION: Patients on long waiting lists for surgery should be reassessed before admission to avoid wasting theatre opportunities, whose cost is the largest component of the total costs of cancelled operations.

Data Collection↗
PubMed1990

Vibration arthrometry. A preview.

Throughout the ages, physicians have listened to sounds and felt vibrations from human joints in their attempts to diagnose pathology. They have used a wide vocabulary to describe these phenomena, but technology has been slow to provide recording and analytic equipment. Lately, accelerometers have been used with considerable success in a new noninvasive method now known as vibration arthrometry (formerly "arthrography"). The technique has been used in early detection of congenital dislocation of the hip and also in diagnosis of meniscal pathology. More recently, patellar vibration has been used to assess the mechanical properties of articular cartilage. Vibration arthrometry has also yielded new information on a possible damage mechanism associated with shock vibration that arises during cavitation of synovial fluid. Joint vibrations are therefore useful aids to diagnosis and may even be etiologic in orthopedic disease.

Hip Dislocation, Congenital↗
PubMed1987

Vibration arthrography as a diagnostic aid in diseases of the knee. A preliminary report.

The detection and recording of vibration emission from human joints, a technique which we have termed "vibration arthrography", is a sensitive, non-invasive method for the objective study of the locomotor system. Using vibration sensors attached to bony prominences around the knee, we studied the joints of both normal and symptomatic subjects. Normal subjects produced three signal types--physiological patellofemoral crepitus, patellar clicks, and the lateral band signal. In symptomatic subjects we identified and categorised many signal types and related them to pathology. Lesions of the menisci produced distinctive signals, and it was possible not only to lateralise the tear, but in many cases to determine the type of meniscal injury present. Vibration arthrography promises to be a useful tool in the non-invasive diagnosis of knee disorders.

Auscultation↗
PubMed1986

The diagnostic potential of vibration arthrography.

The detection and interpretation of vibration emission from the locomotor system is a sensitive, noninvasive method for the objective study of human joints. The projects reviewed here aimed to identify and categorize vibration signals from various joints, chiefly the neonatal hip and the adult knee. Using a vibration detection and computerized analysis system, various studies have suggested that vibration arthrography will be a potentially valuable diagnostic service for the orthopedic surgeon of the 1990s.

Auscultation↗
PubMedDate not supplied

Modelling medical devices: the application of bioengineering in surgery.

Medical device technology has an increasingly important role in surgical procedures. In this article, five case studies of bioengineering in surgery are described as follows: computer-aided design of vascular grafts; middle-ear prostheses; hip prosthesis stems for optimal cement pressurisation; prototype development of a device for measurement of abdominal sounds for monitoring digestive tract activity and a hand-access device for laparoscopic surgery. In each case, new bioengineering design methodologies are demonstrated. The general principles underlying the application of bioengineering in surgery are discussed.

Arthroplasty, Replacement, Hip↗