Poor predictive value of broad-range PCR for the detection of arthroplasty infection in 92 cases.

Background: The diagnosis of prosthetic infection remains a challenge, as no test is 100% sensitive and 100% specific. Recent advances in molecular biology have enabled the detection of infection in culture negative cases.

Patients And Methods: We evaluated the effectiveness of polymerase chain reaction (PCR) in detecting infection in failed joint replacements prospectively in 91 consecutive patients (92 prosthetic joints) undergoing revision total hip or knee arthroplasty.

Howse II cemented titanium metal-backed acetabular cups: poor 10-year results in 107 hips.

We report a retrospective clinical and radiographic review of 107 consecutive primary total hip replacements, using the cemented Howse II prosthesis. The review concentrates on the long-term performance of the acetabular cup, which was designed with a cylindrical titanium metal backing and a polyethylene liner. In all the hips in the series, this cup was used with a modular titanium straight femoral stem and a 32-mm diameter titanium head.

Mid-term results and migration behaviour of a ti-alloy cemented stem.

Between 1991 and 1994, 147 patients (154 hips) underwent a primary cemented total hip replacement using the Ultima ti-alloy, collarless, double-tapered stem and a UHMWPE cup. The average age at operation was 66.4 years.

Failure of an uncemented press-fit acetabular cup in primary total hip arthroplasty.

We reviewed fifteen primary total hip replacements performed using the uncemented, non-porous coated press-fit AcSys Shearer Cup. A modular titanium straight femoral stem with a 32mm head was used in all cases. The mean age of the group containing five males and 10 females was 66 years.

Expression of growth factors, cytokines and matrix metalloproteinases in frozen shoulder.

Frozen shoulder is a chronic fibrosing condition of the capsule of the joint. The predominant cells involved are fibroblasts and myofibroblasts which lay down a dense matrix of type-I and type-III collagen within the capsule. This subsequently contracts leading to the typical features of pain and stiffness.

Prosthetic reconstruction of the femur for primary bone sarcoma.

The survival of patients and implants, complications and functional outcome were reviewed in 25 consecutive femoral endoprosthetic reconstructions for treatment of primary bone sarcoma. The diagnosis was chondrosarcoma in 11, osteosarcoma in 10, MFH in 3 and Ewing's tumour in 1. Median follow up was 64 months (34 to 219) and median age at operation was 29 years (10 to 70).

Sclerosing epithelioid fibrosarcoma.

A case of sclerosing epithelioid fibrosarcoma arising in the thigh of a 40-year-old man is reported. This recently described sarcoma has a distinctive histological appearance which may cause confusion with a variety of other sarcomas with an epithelioid pattern, and indeed with benign soft tissue tumours showing hyalinization. Despite its bland cytology, sclerosing epithelioid fibrosarcoma is capable of metastases, often several years after surgical removal.

Lens curvature measurements by shadow projection profilometry.

A technique is described for measuring spherical and aspherical lens curvature independent of surface contact or dependence on surface smoothness. The shadow of a lens profile is projected onto a CCD pixel array, and its silhouette edge-traced by computer video-image analysis. Nonlinear regression analysis, with correction for axial tilt, calculates lens curvature.

Fracture stiffness measurement in tibial shaft fractures: a non-invasive method.

This paper presents a non-invasive method of assessing healing by measurement of fracture stiffness. The method works on the principle that if the load (F) applied at a certain known distance (Y) from the fracture is measured, then the moment (M = FY) at the fracture site can be calculated. By measuring the angle/deflection (straight theta) occurring at the fracture site using a suitable instrument (electrogoniometer), the necessary data to calculate fracture stiffness (FY/straight theta) would be available.

Stromelysin, gelatinase A and TIMP-1 in prosthetic interface tissue: a role for macrophages in tissue remodelling.

Aseptic loosening of prosthetic components is the most important long-term complication of total joint replacement. To investigate the underlying destructive mechanisms, periprosthetic tissues from both well-fixed and loosened sites from six patients, undergoing surgery for aseptic loosening of knee or hip prostheses, were analysed in detail by immunohistochemical methods for the presence of matrix metalloproteinases and tissue inhibitor of metalloproteinases-1 (TIMP-1). The tissues contained small numbers of cells positive for either collagenase, stromelysin, gelatinase A or TIMP-1; these were randomly distributed, neither specifically next to the bone interface nor to wear particles, and the number of positive cells did not correlate with macroscopic observations at operation.

The effect of the hypermobility syndrome on knee joint proprioception.

Proprioceptive sensory feedback is utilized by the central nervous system for conscious appreciation of the position and movement of the body and limbs. In patients with the hypermobility syndrome (HMS), it has been suggested that there is alteration of proprioceptive acuity. Proprioceptive performance of the knee joint was investigated in 10 female subjects who suffered from HMS using a threshold detection paradigm (accurate determination of the onset and direction of knee joint displacement at constant angular velocity).

Immunolocalisation studies on six matrix metalloproteinases and their inhibitors, TIMP-1 and TIMP-2, in synovia from patients with osteo- and rheumatoid arthritis.

Objective: To assess the likely importance of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in the arthritic process.

Methods: Synovial samples from seven joints with rheumatoid arthritis and three osteoarthritic joints were analysed by indirect immunofluorescence microscopy. Using specific human antisera, we documented the frequencies and distributions of collagenase, stromelysins 1 and 2, matrilysin, gelatinases A and B, TIMP-1, and TIMP-2.

Diffractive optics: the gradial zone lens.

A gradial zone lens has the diffractive component within the bulk lens rather than as a surface-relief profile. It is constructed by spin molding annular zones from microliter volumes of monomers injected into a rotating mold. Plastic lenses have micrometer width zones with dimensions that give a phase difference of modulo 2pi.

Methicillin-resistant Staphylococcus epidermidis in infection of hip arthroplasties.

We investigated the incidence of cephalosporin-resistant bacteria in infected hip arthroplasties. Of 740 patients having hip replacement or related procedures performed over three years, 30 had positive bacteriological cultures from tissue removed at the time of surgery. In 18 of the 30 cultures Staphylococcus epidermidis was grown and 12 of these were methicillin-resistant.

A comparison of gait symmetry and hip movements in the assessment of patients with monarticular hip arthritis.

Three parameters of hip function have been studied and compared in patients with osteoarthritis of the hip. Clinical indices such as the Harris hip score are cheap and easy to perform but can be misleading. Ground reaction force asymmetries are useful in the assessment of disease severity and treatment outcome and are easy to perform and interpret.

Image analysis derived ploidy and proliferation indices in soft tissue sarcomas: comparison with clinical outcome.

Aims: To compare prognostic information obtained by image analysis cytometry of paraffin wax embedded soft tissue sarcomas with conventional assessment.

Methods: A CAS 200 image analyser was used to determine DNA content of Feulgen stained cytology preparations and tissue sections and to quantify immunostaining by Ki67 and PC10 antibodies. A mitotic count in 50 high power fields was undertaken and histological grade assigned by the Trojani system.

Miniature aspheric lenses with spherical index gradients.

Miniature aspheric and anamorphic plastic lenses are built from liquid droplets suspended on circular or elliptical-shaped pedestals. Refractive-index gradients are formed by the flow of premixed monomer volumes through a central conduit by the use of computer-controlled syringe pumps.

Diagnosis of infection and the role of permanent excision arthroplasty.

The symptoms, signs, and investigation of the infected hip replacement are reviewed. Aspiration, combined with needle biopsy of the interface tissue, gives the best opportunity for establishing a bacteriologic diagnosis. The surgical technique for excision arthroplasty is described, and the complications of this procedure reviewed.

Evaluation of pre-admission screening of elderly patients accepted for major joint replacement.

Valuable orthopaedic operating time is frequently lost because patients are found to be medically unfit for surgery on admission. One hundred and forty seven consecutive patients aged 60 years or older, who had been accepted for major joint replacement and who lived within 15 miles of the Western Infirmary, Glasgow were screened at a preadmission clinic. The screening protocol had been agreed by orthopaedic and anaesthetic staff involved in major joint replacement surgery.

Quantitative gamma-ray computed tomography of the radius in normal subjects and osteoporotic patients.

A new design of gamma-ray computed tomography (CT) scanner was used to measure bone density in 516 normal adults and in 116 female patients with osteoporotic fractures. Trabecular bone density (TBD) was measured for a core of the ultradistal radius; cortical bone mass per unit length (MLS) and mass per unit volume (MVS) were computed for the radius shaft. TBD, MLS and MVS peaked at the age of about 40 in females and fell by 32%, 15% and 24%, respectively, by the age of 65.

An investigation of occlusive polyester surgical clothing.

The bacterial dispersion rate of people wearing operating room clothing made from several types of polyester fabric was compared to conventional cotton clothing, total-body exhaust gowns and disposable clothing. Airborne bacteria were measured in a chamber, three ultra-clean air operating rooms and a conventionally ventilated operating room. The polyester clothing was demonstrated to be much superior to conventional cotton clothing and at least as good as the total-body exhaust gowns and disposable clothing.