Biomedical subjects
Publications and source records attributed to R M Atkins.
Twenty-three preserved cadaver upper limbs were dissected to show the level of the nerve supply to flexor carpi radialis and the extent of exposure of a new approach to the flexor surface of the distal radius. We describe a new approach to the flexor surface of the distal radius in which both the radial artery and the median nerve are protected by muscles or tendons.
Relationships were found between the bone-resorbing ability of conditioned media (CMs) from culture of peri-prosthetic tissues and their levels of bone-remodelling agents. Bone-resorbing activity was measured by 45Ca release from pre-labelled mouse calvaria and 23 of 40 CMs exhibited bone-resorbing activity. Cytokine and prostanoid levels in the CMs were measured by immunoassay, and the levels of interleukin (IL)-1 beta, IL-6, tumour necrosis factor alpha (TNF alpha) and prostaglandin E2 (PGE2) correlated with each other, except for the latter two. Significantly higher levels of IL-6 were present in those CMs with bone-resorbing activity than in those without, and a similar pattern was observed for PGE2 and IL-1 beta. However, some CMs with high levels of IL-1 beta, IL-6, TNF alpha and PGE2 failed to induce resorption, whereas a few CMs with low levels of these agents induced resorption. Moreover, neither dialysis of CMs nor addition of neutralizing antisera to IL-1 alpha and IL-1 beta to CMs, either alone or in combination, reduced the bone-resorbing activity of the CMs. It is considered that these agents may act synergistically to mediate osteolysis around failed joint implants, but that other unidentified bone-resorbing agent(s) must be involved.
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Quantitative immunophenotypic analysis of cell types present in peri-prosthetic tissue [pseudosynovial membrane (PSM)] from aseptically loose joint implants revealed considerable heterogeneity between tissues from different individuals. The monocyte/macrophage was the commonest leucocyte type; however, its proportion varied widely. T cells normally accounted for approximately 5% of cells, but in a few cases formed > 20% of cells. In all cases, there was a high ratio of CD4 to CD8 cells. PSM leucocytes were activated in most PSMs as judged by surface expression of CD23, CD25 and CD71. Analysis of the proportions of cell types in PSM, OA synovium and RA synovium revealed similarities between the different tissue types. The levels of IL-1, IL-6 and prostaglandin E produced by the PSM were correlated, but only IL-1 and IL-6 levels correlated with markers of the monocyte/macrophage lineage. This result suggests that prostaglandin E is produced in vivo by many PSM cell types.
The author describes a computer-based model that derives nonnursing staffing requirements from quantifiable performance expectations for structured psychotherapy and rehabilitation therapy. Input variables include treatment mode, contact hours, patient volume (average daily census and average length of stay), hours of structured therapy per week, assessment and discharge activities, and ancillary staff activities. Output variables are number of staff needed, weekly productivity ratios such as hours of direct service per full-time-equivalent position and new patients served per full-time-equivalent position, and hours of structured therapy per day per patient. Initial validation of the model compared its predictions of staffing requirements with predictions based on staffing ratios derived from the literature and with actual staffing levels at the author's institution. The model was used in an analysis of two hypothetical scenarios showing the effects of managed care on variables that influence staffing. The results showed that as average length of stay decreases under managed care, reimbursement based on number of patients served at one time decreases, although costs of providing treatment increase because the program needs more staff to handle the increased number of admissions and discharges.
A novel fine wire bone transport system for use with Ilizarov frames has been used in Bristol. It uses parallel wires instead of crossed wires. Its stiffness has been tested and compared with a crossed wire construct. In its basic form it is not as stiff to bending and shear loading, however, by modification it can be made at least as stiff. A parallel wire construct does not transfix as much soft tissue as a crossed wire construct when used in the leg. This is advantageous, because soft tissue transfixion causes pain and limb swelling, which impair patient mobilization.
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The axial CT scan has become part of our routine management of os calcis fractures. This investigation helps distinguish between tongue and joint depression type fractures, gives important information regarding the fracture pattern in the anterior calcaneum and the degree of comminution of the sustentaculum tali and the subtalar joints. The scan is also useful in determining direction of movement of the body fragment.
Ultrasound measurements of heel pad thickness in 21 patients who had suffered unilateral fractures of the calcaneum were taken. Body weight was also recorded. Contrary to previous assertions in the literature, heel pad thinning was not found to occur and in fact a significant increase in heel pad thickness on the affected side was noted.
This prospective study evaluated the use of the Flowtron intermittent compression garment on 16 patients with stable, resistant, post-traumatic fixed flexion deformity of the elbow. There was a statistically significant reduction of the deformity within 12 weeks. The mean correction obtained was 26 degrees, and in seven patients (44 per cent) full extension was achieved. Maximum flexion showed an average increase of 18 degrees. No relapse of the deformity was observed 2 months after the end of treatment. The use of the Flowtron garment is an effective, safe and simple procedure that can be carried out in the home setting.
OBJECTIVE: To determine whether the previously observed enhanced susceptibility of osteoarthritic (OA) cartilage to tumor necrosis factor-alpha (TNF-alpha) induced degradation could be due to differences in receptor expression. METHODS: Using specific monoclonal antibodies flow cytometry was used to identify and quantify 2 TNF-alpha receptors on the surface of chondrocytes isolated from human articular cartilage. RESULTS: The proportion of chondrocytes expressing p55 TNF-alpha receptor was significantly higher in populations from OA cartilage (p < 0.01) when compared with similar populations from non-arthritic cartilage. The number of p55 receptors/chondrocyte was also significantly higher (p < 0.01) in OA. A significant correlation (r = 0.72, p < 0.18) was found in OA between the numbers of chondrocytes expressing p75 receptor and the number of receptors/chondrocyte. CONCLUSION: p55 TNF-alpha receptor expression is significantly increased on OA chondrocytes ex vivo. Enhanced expression of p55, purported to be the biologically active receptor, could contribute to OA cartilage degradation.
We describe a direct method of measuring the tightness of plaster casts. Tightness was measured weekly in 23 consecutive patients with Colles' fractures. Six had objective signs of algodystrophy nine weeks after the fracture. In these patients the plaster cast was significantly tighter during the first three weeks than in patients who did not develop algodystrophy. The complex relationship between these findings is discussed.
Our previous reports on the pathological anatomy and operative treatment of intra-articular fractures of the calcaneum failed to take account of the fracture pattern anterior to the posterior facet of the subtalar joint. We have reviewed our experience of 63 operative cases and have studied fractures with axial and coronal CT scans reconstructed onto plastic model bones. A constant anterolateral fragment exists, which is displaced by an extended lateral approach to the fracture. If it is unrecognised and unreduced, union in a displaced position may limit hindfoot eversion and disrupt the calcaneocuboid joint. We describe techniques for reduction and fixation of the fragment.
We report four cases in which radiographic features of a fracture of the lateral malleolus and talar tilt of varying severity were associated with a displaced fracture of the calcaneum. In two cases, the initial diagnosis was of a primary ankle injury which led to inappropriate initial management. Gross fracture subluxation of the posterior subtalar joint had occurred in all four cases but could only be fully appreciated after CT examination of the hindfoot. Operative reduction and internal fixation of the calcaneal fracture led to spontaneous reduction of the talar displacement. The association of a swollen hindfoot, talar tilt and a flake fracture of the lateral malleolus must alert clinicians to this injury.
17 patients with established algodystrophy following trauma were treated with serial intravenous regional guanethidine blockade. Subjective improvement occurred in all cases. This improvement could be confirmed quantitatively using objective assessment criteria. The subjective and objective improvements demonstrated in each of the features of algodystrophy correlate closely (p < 0.001). There appears to be no difference in the effectiveness of one block compared to another in the same patient.
We have investigated the appearances of the technetium-99m labelled methylene diphosphonate bone scan in 29 scans performed in 16 patients with post-fracture reflex sympathetic dystrophy (RSD) of the hand. There was a close correlation between increased uptake in the metacarpophalangeal joints and the metacarpal bones, suggesting that the increased uptake in RSD is not confined to the periarticular areas as has been previously reported but occurs throughout the affected region. In seven cases examined 3 months after fracture, RSD was associated with a significant increase in uptake at all sites in the hand on the delayed scan which was not seen in matched post-fracture controls, confirming that increased uptake on delayed bone scintography is a sensitive test for the presence of RSD even in the presence of a fracture of the wrist. The early increased uptake gradually returned to normal. Local tenderness assessed by dolorimetry was correlated with increased uptake, suggesting that the bone scan is not only useful as a diagnostic tool but also provides a quantitative indication of the severity of the condition which may be useful in planning and assessing treatments.
Interleukin 1 induced proteoglycan loss from cartilage in vitro was prevented by a biochemical inhibitor of metalloproteinase activity. The inhibitor also partially relieved the inhibition of proteoglycan synthesis caused by interleukin 1. The loss of glycosaminoglycan by rat and human femoral head cartilage in response to human recombinant interleukin 1 beta (rhIL-1 beta) was established, and the modulation of this loss by the metalloproteinase inhibitor U27391 was investigated. Rat femoral head cartilage consistently lost glycosaminoglycan in response to rhIL-1 beta whereas only a proportion (30%) of normal human femoral head cartilage did so. Concentrations of 10-100 mumol/l U27391 inhibited the action of rhIL-1 beta on rat femoral head cartilage, reversing both the loss of glycosaminoglycan and the inhibition of glycosaminoglycan synthesis. U27391 also prevented the reduction in glycosaminoglycan content of those human femoral head cartilage explants responsive to rhIL-1 beta. Metalloproteinase inhibition therefore prevents rhIL-1 beta induced glycosaminoglycan loss by rat and human femoral head cartilage, suggesting that inhibitors of such enzymes may prove to be of therapeutic benefit in erosive diseases in humans.
OBJECTIVES: To determine the effect of intravenous regional guanethidine on post-traumatic algodystrophy. METHODS: Ten of 20 consecutive patients with algodystrophy after Colles' fracture were treated with serial intravenous regional guanethidine blockades and the other 10 were treated with physiotherapy alone. Patients were assessed before and after each block and then monthly over a six month period. RESULTS: The treated patients had subjective and objective improvements in the assessed features of algodystrophy; treatment resulted in a significant reduction in finger tenderness at five and six months. CONCLUSIONS: Guanethidine blockade induces short term benefits in the symptoms of algodystrophy but improves finger tenderness only in the long term.