Biomedical subjects
Publications and source records attributed to M Brookes.
We perfused 16 human femora with a 50% barium sulphate suspension and studied the intra-osseous vessels by microfocal radiography and histology. There were few anastomoses between the vessels of the greater trochanter and those of the adjacent cancellous bone of the shaft. Ischaemia of the trochanter may contribute to nonunion after trochanteric osteotomy.
The intrinsic blood supplies of 13 human patellae with varying degrees of articular surface degeneration were studied by perfusion techniques. Disruption of the normal pattern of arterial arcades correlated with increasing surface wear.
OBJECTIVE: To determine the factors influencing the risk of an acute traumatic intracranial haematoma in children and adults with a recent head injury. DESIGN: Prospective study of incidence of risk factors in samples of patients attending accident and emergency departments and in all patients having an acute traumatic intracranial haematoma evacuated in one regional neurosurgical unit during 11 years. SETTING: Accident and emergency departments in Scotland or Teesside and regional neurosurgical centre in Glasgow. PATIENTS: 8406 Adults and children (less than or equal to 14 years) who attended accident and emergency departments and 1007 consecutive patients who had an operation for an acute traumatic intracranial haematoma. Data were complete in 8366 and 960 patients respectively. RESULTS: Overall, children were less at risk than adults (one in 2100 v one in 348 respectively). In both age groups the presence of a skull fracture and changes in conscious level permitted identification of subgroups of patients with widely differing degrees of risk. In children the absolute risk ranged from one in almost 13,000 without a fracture or altered conscious level to one in 12 for a child in a coma and with a fracture; the pattern was similar in adults, the risks in corresponding groups ranging from one in almost 7900 to one in four. CONCLUSIONS: Although children attending hospital after a head injury have a lower overall risk of a traumatic haematoma, the main indicators of risk, a skull fracture and conscious level, are the same as in adults, and the pattern of their combined effect is similar. Guidelines for managing adults with recent head injury may therefore be applied safely to children; with the increasing provision of facilities for computed tomography they should be revised to ensure early scanning of more patients with head injury.
STUDY OBJECTIVE: The aim of the study was to examine the differences between child and adult patients attending accident and emergency departments after recent head injuries. DESIGN AND SETTING: A retrospective survey based on existing case records from 23 Scottish accident and emergency departments for 1985 was compared with prospective data from one hospital over 9 months in 1984. PATIENTS: 3838 children under 15 and 4775 adults attended hospital with head injuries during the period analysed. MAIN RESULTS: Only 9% of children and 20% of adults had evidence of brain damage (altered consciousness on arrival, or history of altered consciousness with amnesia on arrival). Scalp lacerations were recorded in approximately 40% of both children and adults, more commonly in those without brain damage. Fewer children than adults had a skull x ray; in both age groups x rays were more often done if there was evidence of brain damage, headache, or vomiting, and less often when there was a scalp laceration. Only 11% of children were admitted compared with 20% of adults. Admission rates per 100,000 population per year were 4011 for children and 1473 for adults (1967 overall); admission rates for brain damage were 290 for children and 341 for adults (331 overall). CONCLUSIONS: These are the first population based estimates of frequency of head injuries presenting at accident and emergency departments, analysed by age, gender and cause of injury. They should be of value when planning services for the head injured.
The vascular repair of a lower tibial transverse osteotomy in the New Zealand white rabbit held in an external fixator was studied in three groups. In the first group, composed of 18 animals, the osteotomy gap was maintained throughout repair. Three animals were killed every two weeks up to 12 weeks postoperatively. In the second group, composed of three animals killed at six weeks, the fragments were brought into contact. In a third and similar group, the osteotomy was compressed. Plain roentgenograms were taken weekly, and intraarterial perfusion with Micropaque was performed when the animals were killed. Roentgenography using fine-grain film, microradiography, and histology were carried out on a midsagittal tibial slice. The results showed that following transverse osteotomy in which the gap was maintained, vascular union of the proximal and distal cortices and associated external callus masses had usually occurred by ten weeks postoperatively. However, an occasional hypovascular zone at the osteotomy site at 12 weeks was associated with fibrous delayed union. In contrast, when apposition or compression of the fragments was used, repair was accelerated, and cortical bone union was established at six weeks. Vascular union of the fragments occurred predominantly through the medullary vessels. The results emphasize the overriding clinical importance of abolition of a fracture gap to achieve rapid revascularization of a fracture and its union by bone.
Postmortem femoral artery perfusion revealed abnormalities in the femoral head pattern of vessels in steroid-treated renal transplant patients as compared with controls. Degenerative changes were found in some of the arteries and arterioles of the hip capsule and femoral head in the renal transplant patients. Two of these patients' femoral heads showed microfocal avascular necrosis. Although high-dose steroids were used in these patients, none had suffered clinically from hip disease while alive. These findings suggest the possibility that local arterial disease may be involved in the pathogenesis of avascular necrosis.
We have evaluated a five-compartment model of [18F]fluoride kinetics in rats. The initial fluoride distribution was found to be similar to that of [77Br]bromide, a known extracellular-fluid (ECF) tracer, in agreement with the hypothesis underlying the model, and the measured uptake rate in rat bones compared well with the digital computer solution. Simpler models did not give a better fit. In dead rats, fluoride movement was found within the skeleton, presumably from bone ECF to bone substance, although not as rapidly as predicted or found in the live animal. Evaluation of the rate constants permitted estimates to be made of cardiac output, skeletal blood flow, and bone ECF volume, all in accord with independent measurements. It is suggested that skeletal blood flow at rest is a constant fraction of body weight, and probably subserves a hematopoietic as well as a mineralization function.
Because of the continuing hazard of post-operative sepsis in joint replacement surgery and the possibility that persistent bone ischemia may be a contributing factor, it is desirable to know the hemodynamic consequences in bone of the implantation of orthopedic acrylic cement. Experiments were carried out on 60 rats. In 30, a bore-hole was made, unilaterally, in the tibia. In another 30, a bore-hole was made in the tibia and a small amount of polymethylmethacrylate cement (Surgical Simplex P) was implanted into the marrow cavity through the bore-hole. By means of 51-Cr labeled red cells and 59-Fe labeled resin particles, the blood volume and blood flow rate in the tibiae were calculated simultaneously as a percentage of the values in the contralateral tibiae. The results showed that at 14 days and 112 days postoperatively, both blood volume and flow were significantly depressed in tibiae in which acrylic cement had been implanted, as compared with tibiae in which only a bore-hole had been made. It was concluded that orthopedic cement implanted into bone renders the bone hypovascular.
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