Showing papers by "Nuffield Orthopaedic Centre published in 1988"
TL;DR: The Oxford Knee, a resurfacing prosthesis with a meniscal bearing, can be used for either bicompartmental or unicompartmentsal arthritis and stability and alignment were restored to normal in nearly all the knees.
Abstract: The Oxford Knee, a resurfacing prosthesis with a meniscal bearing, can be used for either bicompartmental or unicompartmental arthritis. The first 103 unicompartmental cases are presented at a mean time since operation of 36 months (range 21 to 56 months). In those cases with surviving arthroplasties, pain was relieved in 96%. The full range of pre-operative flexion was maintained and flexion deformity was improved from a mean of 6.7 to 5.4 degrees. Stability and alignment were restored to normal in nearly all the knees. Absence of the anterior cruciate ligament was associated with a significantly greater incidence of failure. Six failures occurred in 37 knees lacking a normal anterior cruciate ligament (16.2%); three occurred in 63 knees with a normal anterior cruciate ligament (4.8%) (p less than 0.02). Criteria for the future selection of patients have been deduced from our experience. The operation is recommended for knees with severe unicompartmental osteoarthritis in which all the ligaments are still intact.
296 citations
TL;DR: The method of analysis of back surface shape is described which was designed to present most of the numerical parameters needed to assess the progress of the disease as it affects body shape and indicates quantitatively and with complete safety both lateral asymmetry and deformity in the transverse plane.
138 citations
TL;DR: It is concluded that, even in the presence of adequate iliac crest, the use of bank bone is superior for grafting in idiopathic scoliosis surgery.
Abstract: The results of a study of the use of autograft versus allograft bone in the surgery of idiopathic adolescent scoliosis are presented. Two groups of patients, matched for age, sex, level and angle of curve, received bone grafts, 20 patients having autogenous bone from the iliac crest and the other 20 having donor bone from a bone bank. Both groups had otherwise identical posterior fusions and Harrington instrumentation. There was no difference between the two groups in a blind, radiographic assessment of bone graft mass at six months, nor in maintenance of the curve correction over the same period. No major operative complications nor failures of instrumentation were encountered. There was, however, a marked reduction in operative time and blood loss in the patients receiving donor bone and also a much lower incidence of late symptoms relating to the operative sites. We conclude that, even in the presence of adequate iliac crest, the use of bank bone is superior for grafting in idiopathic scoliosis surgery.
128 citations
TL;DR: An optical scanner is described which has been designed primarily for the measurement of human back shape and sets of algorithms are described which derive geometric parameters from the calibration scan and which sort surface shape coordinates, outline them and detect special markers from the surface shape scan.
72 citations
TL;DR: A 'clamp on' transducer has been developed which, when fitted to the support column of an external fixator, enables the stiffness of a fracture to be determined during the healing process.
63 citations
TL;DR: It is suggested that recruitment of SLCs of marrow origin is important in the production of intimal hyperplasia in both RA and OA and that there is also a significant local proliferation of non‐marrow derived SLCS in OA.
Abstract: The immunohistology of synovial lining cells (SLCs) in normal and inflamed hyperplastic synovium was investigated using monoclonal antibodies directed against leucocyte common antigen (LCA) HLA-DR and other macrophage components. We found that some SLCs in normal synovium express LCA, HLA-DR, and monocyte/macrophage-associated antigens. The number of SLCs expressing these antigens is increased in hyperplastic osteoarthritic (OA) and rheumatoid (RA) synovium. Some SLCs which did not react for LCA or other macrophage markers but were positive for HLA-DR were also noted in normal synovium and some segments of hyperplastic OA synovium. SLCs which are positive for LCA, HLA-DR, and macrophage markers contribute to the intimal hyperplasia in RA where they account for the majority of SLCs in the synovial intima. In OA synovium, the distribution of SLCs showing this pattern of reactivity was less uniform with numerous SLCs which were positive for HLA-DR but negative for LCA and other macrophage markers also present in the synovial intima. These findings indicate that there are some SLCs of bone marrow origin in normal and hyperplastic synovium. They also suggest that recruitment of SLCs of marrow origin is important in the production of intimal hyperplasia in both RA and OA and that there is also a significant local proliferation of non-marrow derived SLCs in OA.
58 citations
TL;DR: The value of surface topographical measurements in the assessment of curve progression in adolescent idiopathic scoliosis is demonstrated in a group of 51 patients and eight patients who underwent spinal instrumentation were correctly predicted as candidates for surgery.
Abstract: The value of surface topographical measurements in the assessment of curve progression in adolescent idiopathic scoliosis is demonstrated in a group of 51 patients. Cobb angles at the commencement of the study ranged from 10 degrees -55 degrees (mean 34.5 degrees), and the mean follow-up period was greater than 2 years. The surface shape method correctly identified curve evolution in 84% of the patient group. Of these, the eight patients who underwent spinal instrumentation were correctly predicted as candidates for surgery.
57 citations
TL;DR: Wound viability was found to be significantly reduced following knee arthroplasty, and the lateral wound edge is more hypoxic than the medial, but there were no significant differences between the three incisions.
Abstract: The viability of three incisions for knee arthroplasty were analysed by transcutaneous estimation of the skin oxygen tension. Wound viability was found to be significantly reduced following knee arthroplasty. The lateral wound edge is more hypoxic than the medial, but there were no significant differences between the three incisions.
52 citations
TL;DR: Injuries to all regions of the body increased with age and with the weight of the vehicle in the collision, and accidents most often concerned young children or the elderly.
Abstract: Although there have been many reports on injuries to occupants of cars in road traffic accidents, there have been few prospective studies of injuries to pedestrians in such accidents. For this reason a two year prospective study of pedestrians in road traffic accidents in the Oxford region was carried out. The incidence of death in pedestrians was significantly higher than in car occupants or motorcyclists. The principal determinant of death was the weight of the vehicle concerned. The most common site of injury was the head because of a high incidence of brief concussion, but the most common site of serious injuries was the leg. Injuries to all regions of the body increased with age and with the weight of the vehicle in the collision. Accidents most often concerned young children or the elderly.
48 citations
TL;DR: Detailed anatomical study in cadavers of the blood supply to the graft demonstrates cutaneous arteries arising from the peroneal artery and then passing along the posterior surface of the lateral intermuscular septum.
Abstract: The use of an osteocutaneous free fibular graft as a single-stage reconstructive procedure for composite tissue loss is increasingly common. Detailed anatomical study in cadavers of the blood supply to the graft demonstrates cutaneous arteries arising from the peroneal artery and then passing along the posterior surface of the lateral intermuscular septum. These vessels pierce the crural fascia and then ramify to supply the skin. Knowledge of the vascular anatomy of the skin overlying the fibula is essential to the success of the graft.
45 citations
TL;DR: Bilateral posterior interosseous nerve palsy in a rheumatoid patient is described and steroid injection into the elbow may not produce lasting recovery and may lead to unacceptable delay before surgical decompression.
Abstract: Bilateral posterior interosseous nerve palsy in a rheumatoid patient is described. Six previous case reports and our experience indicate that steroid injection into the elbow may not produce lasting recovery and may lead to unacceptable delay before surgical decompression. An anterolateral approach for division of the arcade of Frohse is effective in cases with diffuse synovitis; where there is a local cystic swelling a posterolateral approach provides better access. Good recovery of nerve function can be expected after early operation.
01 Jan 1988
TL;DR: Biomechanical parameters of stance and balance were recorded in ten unilateral lower limb amputees at the beginning and end of walking training to monitor progress and can accurately record improvement for research purposes.
Abstract: Biomechanical parameters of stance and balance were recorded in ten unilateral lower limb amputees at the beginning and end of walking training. Measurements were carried out using a Double Video Forceplate (DVF), a machine developed at University College, London, Bioengineering Centre, Roehampton. During free standing on the DVF there was a mean increase in weight-bearing under the prosthetic foot from 32% body weight (1st session) to 41% body weight (final session), p less than 0.01. Maximum weight-bearing during leaning as far as possible onto the prosthesis increased from a mean of 54% body weight to 63% body weight, p less than 0.01. These simple measurements of weight distribution between the feet can be of value during walking training to monitor progress and can accurately record improvement for research purposes.
TL;DR: 95 patients with previously treated congenital dislocation of the hip who underwent femoral osteotomy after the age of five years were described, with the commonest indication for surgery was progressive uncovering and subluxation of the femoral head.
Abstract: We describe 95 patients with previously treated congenital dislocation of the hip who underwent femoral osteotomy after the age of five years. The commonest indication for surgery was progressive uncovering and subluxation of the femoral head; other reasons were coxa vara, long leg dysplasia and persistent anteversion. Femoral osteotomy for uncovering of the femoral head (Severin Grade III) in this age group gave good results at maturity only when the acetabular angle was less than 25 degrees before operation. Femoral osteotomy alone was inadequate for true subluxation of the hip (Severin Grade IV).
TL;DR: A greater potential for hypoxanthine-xanthine oxidase generated oxygen free radical formation in Dupuytren's contracture than in control palmar fascia is suggested, as allopurinol binds to xanthine oxidation and prevents release of free radicals.
Abstract: The concentration of substrate expressed as hypoxanthine capable of reacting with xanthine oxidase to release superoxide free radicals (O2-) was measured in control and Dupuytren's contracture palmar fascia. In Dupuytren's contracture palmar fascia the concentration of hypoxanthine was six times that of control and was greatest in \"nodular\" areas. Xanthine oxidase activity was also detected in Dupuytren's contracture palmar fascia. These results suggest a greater potential for hypoxanthine-xanthine oxidase generated oxygen free radical formation in Dupuytren's contracture than in control palmar fascia. Production of free radicals may be an important factor in the pathogenesis of Dupuytren's contracture. The benefit of allopurinol in the management of Dupuytren's contracture and other fibrotic conditions may thus be explained, as allopurinol binds to xanthine oxidase and prevents release of free radicals.
01 Jan 1988
TL;DR: The object is to calculate the magnitudes of the forces transmitted by the articular surfaces, ligaments and muscle tendons at the human knee in the presence of external load and as a result of antagonistic muscle action.
Abstract: Dr. Mueller’s book (1983) cites 404 references to clinical and experimental investigations of the human knee. This is only a portion of the growing volume of published experimental work that demands, for its understanding, the development of theoretical models of the joint. These models could provide a basis for the design of experiments and the interpretation of their results. The work reported in this paper is one such development. It represents a series of hypotheses about the functional anatomy of the joint. Our object is to calculate the magnitudes of the forces transmitted by the articular surfaces, ligaments and muscle tendons at the human knee in the presence of external load and as a result of antagonistic muscle action. The results of such calculations can subsequently be compared to actual measurements in order to test the validity of the hypotheses. In this paper, we describe only the response in the sagittal plane to loads applied to the lower limb. Before we can proceed with the study of the mechanics, it is first necessary to determine the position and direction of the lines of action of the muscle, ligament and contact forces. We will start with a study of the geometry of the joint.
TL;DR: The Oxford Optical Pointer is developed and the principle by which it converts relative direction into analogue electrical signals is described and its application as a head-mounted device for controlling an electric wheelchair is presented.
Abstract: For some disabled people pointing provides a more convenient means of communication and control than the use of switches. The quadriplegic who retains good control of head movement can be provided with a number of input alternatives, but no existing system meets all the requirements of a general-purpose electronic pointing device. Consequently the Oxford Optical Pointer has been developed. The principle by which it converts relative direction into analogue electrical signals is described and its application as a head-mounted device for controlling an electric wheelchair is presented.
TL;DR: The paper describes the use of two non-invasive techniques to provide simultaneous measurements of interface pressures and back shape in the seated posture and the effects of varying seat angulation with four normal subjects.
TL;DR: It is suggested that over-the-mains signalling should be incorporated into 'standard' environmental control systems available from the DHSS, allowing a reduction in cost and size.
Abstract: Advances in speech recognition technology may in future allow the severely disabled to gain greater control over their environment. VADAS (Voice activated domestic appliance system) is a voice recognition and mains signalling system that was marketed for use by the disabled. We have evaluated VADAS using 19 severely disabled patients living in the community. Only seven of the 19 found VADAS to be an effective environmental control system over a period of four weeks. Major difficulties in achieving voice recognition leading to annoyance and frustration were experienced by the remaining 12. Only one of the eight long-term users of Possum PSU 3 preferred VADAS. The over-the-mains signalling system functioned well in 18 of the 19 homes. We suggest that over-the-mains signalling should be incorporated into 'standard' environmental control systems available from the DHSS, allowing a reduction in cost and size. VADAS is one available option for switching, although further development work is necessary to make it...
TL;DR: An experiment is described in which platinum electrodes were immersed in a saline paste containing pH indicator and stimulation pulses applied, and the observed electrode was first a direct- coupled cathode, and later made a directcoupled anode.
Abstract: biphasic ('Lilly') stimulating pulses necessary in a neurological prosthesis? II pH changes; noxious products; electrode corrosion; discussion' (Medical & Biological Engineering & Computing, 1986, 24, 50-56), Section 2, an experiment is described in which platinum electrodes were immersed in a saline paste containing pH indicator and stimulation pulses applied. The observed electrode was first a direct-coupled cathode, and later made a directcoupled anode. With the electrode 'well exhausted', the Charges per pulse which caused detectable pH change near the electrode were 250 and 167/zC per geometric cm 2, respectively. I n Section 2.1.7, assuming an etch factor (surface roughness) of 1.5, the charge densities per real crn 2
01 Jan 1988
TL;DR: The Oxford knee is developed, the first implant to provide an analogue of the natural meniscus free to glide and spin upon the flat tibial plateau, and the clinical results of 125 knees treated since 1978 with this device in its bicompartmental form compared well with previously reported series.
Abstract: In 1978 the present authors suggested the use of free meniscal bearings in the design of a knee prosthesis [1]. From this theory we developed the Oxford knee, the first implant to provide an analogue of the natural meniscus free to glide and spin upon the flat tibial plateau (Fig. 1). In 1986, we published the clinical results of 125 knees treated since 1978 with this device in its bicompartmental form [2]. Relief of pain, restoration of mobility and recovery of function all compared well with previously reported series. In 1982, having observed a number of knees devoid of cartilage on one side and nearly normal on the other, we decided to try the device as a unicompartmental implant. Theoretically, the design would seem to be ideal, as since both the tibial and the femoral components are metal, they can both be very thin, necessitating the removal of very little bone, particularly from the tibia. The meniscal bearings come in a range of thicknesses with feeler gauges to match, so that exactly the right size can be implanted to tension the ligaments after the metal components have been fixed to the bone. The components are perfectly congruous throughout the range of movements, minimising wear and the ill effects of the products of wear upon the retained articular cartilage in the other compartment of the knee (Fig. 2).
TL;DR: The leg positioner has proved useful during knee arthroplasty, high tibial osteotomy, arthroscopic procedures, and ligament reconstruction, and has reduced fatigue, freed the assistant for other tasks, and held the limb more firmly than was possible hitherto.
Abstract: A novel leg-positioning and holding mechanism has been developed to facilitate knee surgery. The normal thigh tourniquet is used as the point of attachment of the mechanism. The knee may be placed in any of the positions desired for knee surgery by means of a single control lever. To facilitate alignment during arthroplasty a pointer has been incorporated to indicate the midline of the limb. The leg positioner has proved useful during knee arthroplasty, high tibial osteotomy, arthroscopic procedures, and ligament reconstruction. Its use has reduced fatigue, freed the assistant for other tasks, and held the limb more firmly than was possible hitherto.