Search PubMed⌕ Search

Biomedical subjects

R L Cruess

Publications and source records attributed to R L Cruess.

At least 37 records · Page 2Linked to original sources
PubMed1984

The response of articular cartilage to weight-bearing against metal. A study of hemiarthroplasty of the hip in the dog.

Hemiarthroplasty of the hip and some other joints has been used for many years with satisfactory results, but the fate of articular cartilage when weight-bearing against metal has not been reported. Replacement of the head of the femur was carried out in one hip of each of 26 dogs, and the changes in acetabular cartilage studied at intervals of up to 24 weeks. There was early loss of proteoglycan, followed by surface damage to the cartilage, progressive degenerative changes, and growth of pannus from the articular margins. At 24 weeks after operation there was little remaining articular cartilage, while intense subchondral activity suggested that the bony skeleton was being remodelled to conform to the shape of the prosthesis. This study is not intended to suggest that hemiarthroplasty does not help patients.

Acetabulum↗
PubMed1984

Hormone receptors in the epiphysial cartilage.

In order to assess which hormones may exert direct effects on skeletal growth at the epiphysial growth plate, the specific binding of hormones to the epiphysial cartilage of growing dogs and rabbits was studied. Membrane fractions obtained by centrifugation of homogenates prepared from dog and rabbit growth plate cartilage at 600, 15 000 and 105 000 g showed significant specific binding of serum insulin-like activity and insulin. Binding of growth hormone and prolactin by the three membrane fractions was negligible. Saturable binding sites for triiodothyronine could be demonstrated in nuclei from the dog growth plate. Nuclear binding showed an apparent Kd of 11 +/- 3.6 nmol/l and a maximum binding capacity of 4.1 +/- 1.6 pmol/mg DNA, a level comparable to dog liver. Using a viable chondrocyte suspension prepared from dog epiphysial cartilage, specific steroid binding in the cells could be demonstrated for [3H]dexamethasone but not 17 alpha-methyltrienolone, oestradiol-17 beta or 1 alpha, 25-dihydroxycholecalciferol. Scatchard analysis of dexamethasone binding showed high affinity binding sites having a Kd of 1.2 +/- 0.35 nmol/l and a capacity of 1700 sites/cell, and a low affinity binding with a Kd of 109 +/- 57 nmol/l and a capacity of 24 000 sites/cell. Steroid competition for the specific binding showed the following sequence of affinity: dexamethasone greater than corticosterone greater than 11-deoxycortisol greater than testosterone greater than oestradiol-17 beta.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Zonal analysis of cytoplasmic steroid hormone receptor levels: replication and synthetic activity in embryonic calf growth cartilage.

Using the dextran charcoal method, a specific steroid receptor for dexamethasone, but not 17 beta-estradiol or 17 alpha-methyltrienolone, was demonstrated in cytosol prepared from mid-gestation fetal calf growth cartilage. Zonal analysis of cytoplasmic receptor levels showed that tissue sections from the center, the peripheral surface, and the palisade section bound 229 +/- 111, 173 +/- 64, and 15 +/- 28 femtomole dexamethasone per mg of protein, respectively. Incorporation of 3H-thymidine, 35S-sulfate, and 3H-proline into cartilaginous tissues was used as an index of replication and synthetic activity. The percentage of 3H-thymidine labeled nuclei, as determined by radioautography, showed that the palisade zone has a significantly lower replicating activity (P less than 0.001). Values were 5.6 +/- 1.2, 5.4 +/- 1.2, 3.8 +/- 1.3, and 1.1 +/- 0.2 for the center, peripheral surface, and upper and lower half of the palisade section. The rate of sulfate and proline incorporation into the palisade zone was over seven times higher than the central and peripheral surface (P less than 0.001). The difference in the rate of matrix synthesis and proliferating activity in these regions may be related to the zonal heterogeneity of receptor levels of glucocorticoids in fetal growth cartilage.

Animals↗
PubMed1982

Pigmented villonodular synovitis of joints.

In a series of 38 young adults with intra-articular pigmented villonodular synovitis, the joint predominantly affected was the knee. For early diagnosis of intra-articular pigmented villonodular synovitis, a high level of suspicion is necessary for patients with complaints of persistent pain or swelling in the knee, or erosive osteoarthritis of the hip and shoulder of unknown etiology in young individuals. Arthrography of the knee was not found to be a very helpful test in the diagnosis of pigmented villonodular synovitis. Localized intra-articular pigmented villonodular synovitis should be treated by local excision. Diffuse intra-articular pigmented villonodular synovitis of the knee should be treated by extensive synovectomy followed by manipulation under general anesthesia two to three weeks postsurgery. Intra-articular pigmented villonodular synovitis of the shoulder and hip should be treated by extensive synovectomy or by total joint arthroplasty in cases with marked bone destruction and cyst formation.

Adolescent↗
PubMed1982

A retrospective study of Moore and Thompson hemiarthroplasty. A review of 599 surgical cases and an analysis of the technical complications.

In a retrospective review of 580 patients with 599 hemiarthroplasties of the hip, 454 operations (75.8%) were carried out as primary procedures for fresh intracapsular fractures, and 145 operations (24.2%) were performed as salvage procedures. The three-month mortality rate was 5.0%, and the dislocation rate was 5.3%. The early results were assessed by roentgenograms alone; head size, neck length, stem-shaft angle, and calcar seating were measured on preoperative and postoperative films. Anteversion and retroversion could not be accurately assessed. Using an arbitrary rating system, the results were graded as excellent on the basis of four anatomical criteria: good, on the basis of three; fair, of two; and poor, on only one or none. Only 173 prostheses (26.3%) were graded as excellent and 103 (27.3%) as good. At least 70 (25.3%) were just fair, and 31 (11.2%) were poor. Inappropriate neck length was present in 55.0% of the dislocated prostheses, incorrect head size in 25.0%, varus of the prosthesis in 20.0%, and poor calcar seating in 25.0%. Thus, technical errors account for a significant number of imperfect hemiarthroplasties of the hip. Careful attention to detail should decrease the incidence of errors and improve end-results.

Adult↗
PubMed1981

Post-operative neuropathic fractures in patients with myelomeningocele.

Neuropathic fractures are common after major surgical procedures to stabilize the hip or spine in patients with myelomeningocele. Complications resulting from such fractures are frequently observed. The fractures occur particularly in the more severely involved children and are associated with prolonged immobilization after surgery. The authors advise that all necessary surgery be done within the shortest possible time, and urge that prolonged immobilization be avoided if possible.

Child↗
PubMed1981

Steroid-induced osteonecrosis: a review.

Between 1963 and 1980 cortisone-induced osteonecrosis has been seen in 122 patients at the Royal Victoria Hospital, Montreal. Of these, 68 had had renal homotransplants; the others suffered from a variety of conditions. The femoral head was most commonly affected; the humeral head, distal femur, proximal tibia, talus and capitellum were also involved. There were two patterns of involvement, similar in all locations. The more common is subchondral osteolysis, which may heal without operation. The other is similar to osteochondritis dissecans and requires operation. Alteration in fat metabolism is the most likely cause of the condition. Vascular occlusion and bone death may result from an increase in fat cell size or from fat embolization. Treatment should be conservative as often as possible, but gratifying results have been obtained in those patients requiring surgical procedures.

Cortisone↗
PubMed1980

The results and complications of surgery for the paralytic hip and spine in myelomeningocele.

We have reviewed the results of operations to stabilise the paralytic hip and to correct and stabilise the deformed spine of children with myelomeningocele. Despite a high complication rate the spinal operations were frequently successful. The hip operations were less satisfactory, with stabilisation of the hip eventually achieved in 69 per cent of the patients and improved walking in only 27 per cent. We do not recommend that such operations be undertaken on the hips of children with a level of paralysis at L3 or above. If stabilisation is indicated multiple combined procedures produce the best result.

Child↗
PubMed1979

Melorheostosis in children. Clinical features and natural history.

Experience in the management of fourteen children with melorheostosis has been reviewed. The principal and presenting clinical features were unilateral soft-tissue contractures associated with inequality of limb length. In contrast to the disease in adults, pain occurred infrequently and was never intense. The average interval between the discovery of the clinical features and the correct diagnosis was six years. The distinctive radiographic feature in the child was an endosteal pattern of hyperostosis marked by streakiness of the long bones and spotting of the small. This differs from the usual subperiosteal or extracortical pattern of hyperostosis seen in adults. The surgical treatment of the contractures proved difficult and recurrence of the deformity was the rule. Distal ischaemia occurred when the chronically contracted and flexed joint was rapidly extended.

Adolescent↗
PubMed1979

Orthopedic surgery today.

The history of orthopedic surgery in Canada is briefly reviewed. It appears that the problems which were posed in the 1960s and early 1970s have diminished in importance. They related to the shortage of orthopedic manpower and to the lack of a sound scientific base within universities. There appears now to be an adequate number of orthopedic surgeons to handle the needs of the population, and Canadian training programs are providing replacements at an appropriate rate. Future problems will in all probability relate to the interrelationship between society and the medical profession. Academic freedom and mobility of medical manpower must be preserved at all costs and the orthopedic profession must adapt to an ever-changing situation if future developments are to be as satisfying as our very exciting past.

Canada↗
PubMed1978

Changes in organic matrix of bone and of bone and blood ATP in rats fed rachitogenic diets.

Vitamin D deficient and phosphate deficient states were produced in young rats by the use of synthetic diets. Whole blood ATP, serum calcium and phosphorus and the ash, phospholipid, hexosamine and hydroxyproline contents of metaphyseal bones of control and rachitic rats were measured after 4 weeks on the diets. There was a decrease in whole blood ATP and serum phosphorus of the rachitic rats, and in the contents of ash, phospholipid and hexosamine of the rachitic metaphyses, while the hydroxyproline contents of the rachitic bones were higher than those of the controls. Subcutaneous injection of ATP or inorganic phosphate in rats, fed a low phosphate diet deficient in vitamin D, caused an increase in serum phosphorus and blood ATP levels and in metaphyseal ash contents. It is suggested that some of the metabolic disturbances in rickets are due to alteration in ATP production.

Adenosine Triphosphate↗