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 Environmental contamination was present in an area of 6 x 8 m for both devices. The concentration of contamination was lower for the ultrasound device. Both the ultrasound and the high-speed cutter contaminated all members of the surgical team. The devices tested produced aerosols which covered the whole operating theatre and all personnel present during the procedure. In contaminated and infected patients, infectious agents may be present in these aerosols. We therefore recommend the introduction of effective measures to control infection and thorough disinfection of the operating theatre after such procedures.
Lesions within the articular cartilage layer of synovial joints do not heal spontaneously. Some repair cells may appear, but their failure to become established may be related to problems of adhesion to proteoglycan-rich surfaces. We therefore investigated whether controlled enzymatic degradation of surface proteoglycan molecules to a depth of about 1 μm, using chondroitinase ABC, would improve coverage by repair cells. We created superficial lesions (1.0 × 0.2 × 5 mm) in the articular cartilage of mature rabbit knees and treated the surfaces with 1 U/ml of chondroitinase ABC for four minutes. The defects were studied by histomorphometry and electron microscopy at one, three and six months. At one month, untreated lesions were covered to a mean extent of 28% by repair cells; this was enhanced to a mean of 53% after enzyme treatment. By three months, the mean coverage of both control and chondroitinase-ABC-treated defects had diminished dramatically to 0.2% and 13%, respectively, but at six months both untreated and treated lesions had a similar coverage of about 30%, not significantly different from that achieved in untreated knees at one month. These findings suggest that, with time, chondrocytes near the surface of the defect may compensate for the loss of proteoglycans produced by enzyme treatment, thereby restoring the inhibitory properties of the matrix as regards cell adhesion. This supposition was confirmed by electron microscopy. Our results have an important bearing on attempts made to induce healing responses by transplanting chondrogenic cells or by applying growth factors.
Rebound growth after hemiepiphysiodesis may be
a normal event, but little is known about its causes, incidence
or factors related to its intensity. The aim of this study was to
evaluate rebound growth under controlled experimental conditions. A total of 22 six-week-old rabbits underwent a medial proximal
tibial hemiepiphysiodesis using a two-hole plate and screws. Temporal
growth plate arrest was maintained for three weeks, and animals
were killed at intervals ranging between three days and three weeks
after
Objectives. There are various pin-in-plaster methods for treating fractures
of the distal radius. The purpose of this study is to introduce
a modified technique of ‘pin in plaster’. Methods. Fifty-four patients with fractures of the distal radius were
followed for one year post-operatively. Patients were excluded if
they had type B fractures according to AO classification, multiple
injuries or pathological fractures, and were treated more than seven
days after injury. Range of movement and functional results were
evaluated at three and six months and one and two years post-operatively.
Radiographic parameters including radial inclination, tilt, and
height, were measured pre- and post-operatively. Results. The average radial tilt was 10.6° of volar flexion and radial
height was 10.2 mm at the sixth month post-operatively. Three cases
of pin tract infection were recorded, all of which were treated
successfully with oral antibiotics. There were no cases of pin loosening.
A total of 73 patients underwent surgery, and three cases of radial
nerve irritation were recorded at the time of cast
Concomitant tumour resistance (CTR) is a unique phenomenon in which animals harbouring large primary tumours are resistant to the growth of smaller metastatic tumours by systemic angiogenic suppression. To examine this clinically, in ten patients with osteosarcoma, we investigated the effects of
When transferring tissue regenerative strategies
involving skeletal stem cells to human application, consideration needs
to be given to factors that may affect the function of the cells
that are transferred. Local anaesthetics are frequently used during
surgical procedures, either administered directly into the operative
site or infiltrated subcutaneously around the wound. The aim of
this study was to investigate the effects of commonly used local anaesthetics
on the morphology, function and survival of human adult skeletal
stem cells. Cells from three patients who were undergoing elective hip replacement
were harvested and incubated for two hours with 1% lidocaine, 0.5%
levobupivacaine or 0.5% bupivacaine hydrochloride solutions. Viability
was quantified using WST-1 and DNA assays. Viability and morphology
were further characterised using CellTracker Green/Ethidium Homodimer-1
immunocytochemistry and function was assessed by an alkaline phosphatase
assay. An additional group was cultured for a further seven days
to allow potential recovery of the cells after
The intermittent administration of parathyroid hormone (PTH) increases the formation of bone by stimulating osteoblastic activity. Our study evaluates the possibility that intermittent treatment with PTH (1-34) may also enhance the implant-bone fixation of stainless-steel screws. Twenty-eight rats received one screw in either one (n = 8) or in both (n = 20) proximal tibiae. We administered either PTH (1-34) in a dosage of 60 μg/kg/day (n = 14) or vehicle (n = 14) over a period of four weeks. At the end of this time, the degree of fixation was assessed by measuring the
This protocol describes a pragmatic multicentre
randomised controlled trial (RCT) to assess the clinical and cost
effectiveness of arthroscopic and open surgery in the management
of rotator cuff tears. This trial began in 2007 and was modified
in 2010, with the
We used a goat model of a contaminated musculoskeletal defect to determine the effectiveness of rapidly-resorbing calcium-sulphate pellets containing amikacin to reduce the local bacterial count. Our findings showed that this treatment eradicated the bacteria quickly, performed as well as standard polymethylmethacrylate mixed with an antibiotic and had many advantages over the latter. The pellets were prepared before surgery and absorbed completely. They released all of the antibiotic and did not require a subsequent operation for their
We examined osteochondral autografts, obtained at a mean of 19.5 months (3 to 48) following extracorporeal irradiation and re-implantation to replace bone defects after
The aim of this biomechanical study was to investigate the role of the dorsal vertebral cortex in transpedicular screw fixation. Moss transpedicular screws were introduced into both pedicles of each vertebra in 25 human cadaver vertebrae. The dorsal vertebral cortex and subcortical bone corresponding to the entrance site of the screw were removed on one side and preserved on the other. Biomechanical testing showed that the mean peak pull-out strength for the inserted screws, following
We have designed a prospective study to evaluate
the usefulness of prolonged incubation of cultures from sonicated
orthopaedic implants. During the study period 124 implants from
113 patients were processed (22 osteosynthetic implants, 46 hip
prostheses, 54 knee prostheses, and two shoulder prostheses). Of
these, 70 patients had clinical infection; 32 had received antibiotics
at least seven days before
Metaphyseal tritanium cones can be used to manage the tibial bone loss commonly encountered at revision total knee arthroplasty (rTKA). Tibial stems provide additional fixation and are generally used in combination with cones. The aim of this study was to examine the role of the stems in the overall stability of tibial implants when metaphyseal cones are used for rTKA. This computational study investigates whether stems are required to augment metaphyseal cones at rTKA. Three cemented stem scenarios (no stem, 50 mm stem, and 100 mm stem) were investigated with 10 mm-deep uncontained posterior and medial tibial defects using four loading scenarios designed to mimic activities of daily living.Aims
Methods
We have studied the effects of bupivacaine on human and bovine articular chondrocytes in vitro. Time-lapse confocal microscopy of human articular chondrocytes showed >
95% cellular death after exposure to 0.5% bupivacaine for 30 minutes. Human and bovine chondrocytes exposed to 0.25% bupivacaine had a time-dependent reduction in viability, with longer exposure times resulting in higher cytotoxicity. Cellular death continued even after
The Attune total knee arthroplasty (TKA) has been used in over 600 000 patients worldwide. Registry data show good clinical outcome; however, concerns over the cement-tibial interface have been reported. We used retrieval analysis to give further insight into this controversial topic. We examined 12 titanium (Ti) PFC Sigma implants, eight cobalt-chromium (CoCr) PFC Sigma implants, eight cobalt-chromium PFC Sigma rotating platform (RP) implants, and 11 Attune implants. We used a peer-reviewed digital imaging method to quantify the amount of cement attached to the backside of each tibial tray. We then measured: 1) the size of tibial tray thickness, tray projections, peripheral lips, and undercuts; and 2) surface roughness (Ra) on the backside and keel of the trays. Statistical analyses were performed to investigate differences between the two designs.Objectives
Methods
We describe a technique for measuring the Stiffness of regenerate bone after leg lengthening. This allows early identification of slow healing by reference to normal patterns. We determined the time of
We immobilised the right hindlimbs of six-month-old female Wistar rats for four weeks using a biplanar external fixation bridging the knee. The untreated left limbs served as a control group. An additional group of rats was allowed to recover for four weeks after