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Biomedical subjects

D L Hamblen

Publications and source records attributed to D L Hamblen.

At least 37 records · Page 2Linked to original sources
PubMed1987

Surgical stabilisation of the rheumatoid cervical spine. A review of indications and results.

We have reviewed 32 patients with rheumatoid disease of the cervical spine who underwent a total of 40 operations aimed at correcting instability and improving any associated neurovascular deficit. Apart from four patients with intractable pain, the main indication for surgery was progressive neurological impairment. Of the 32 primary operations, 19 (60%) were successful; the remainder failed to achieve their objective and there were two deaths in the immediate postoperative period. Of eight secondary operations performed for recurrence of symptoms or failure to relieve cervical myelopathy, only four were successful. Of nine operations for bony decompression to relieve cord compression from irreducible subluxation, only four were successful. The overall results show a success rate of 57% and a failure rate of 35% with early operative mortality in 8%. Indications for operation are discussed and earlier diagnosis is considered to be the key to improved results.

Aged↗
PubMed1987

Sarcoma at the site of a single hip screw. A case report.

We report a case of malignant fibrous histiocytoma of the hip which occurred 30 years after the insertion of a single chrome-cobalt alloy screw for a slipped femoral epiphysis. The possible aetiological association between malignant tumours and metallic implants is discussed.

Adult↗
PubMed1987

Distal metatarsal osteotomy for hallux valgus in the middle-aged patient.

Thirty-eight distal metatarsal osteotomies for hallux valgus in middle-aged patients between the ages of 50 and 67 years were performed over a period of five years. None of the patients could be rated with an excellent result. Good results were noted in only 52.6%. Poor results were attributable to imperfect surgical technique, severity of preoperative deformity, osteoporosis, and preexisting osteoarthritic changes at the first metatarsophalangeal joint.

Aged↗
PubMed1985

Vascular complications of osteochondroma.

Apart from trauma, symptoms arising from peripheral arteries are very unusual in adolescents and young adults. Three cases of osteochondroma associated with rare vascular complications are presented, together with a review of the literature. The development of pain in relation to osteochondroma does not necessarily imply trauma or the onset of malignancy and vascular complications should be considered, particularly if the bone lesion occurs around the knee. In this situation, arteriography is considered essential in planning surgical treatment and the importance of angiography in two planes is emphasised.

Adolescent↗
PubMed1983

A bacteriologically occlusive clothing system for use in the operating room.

A comparison was made in a laminar-flow operating room between total-body exhaust gowns and a clothing system made from Fabric 450. This disposable clothing was found to be much more comfortable and convenient than the total-body exhaust gowns. The average airborne bacterial counts obtained during total hip replacement operations from each of the clothing systems were identical when the downflow method of ventilation was used (0.7 per cubic metre) and no significant difference could be demonstrated when the crossflow system was used (2.2 per cubic metre with the total-body exhaust gowns and 3.1 per cubic metre with the disposable clothing). Tests in a dispersal chamber were carried out to find the effectiveness of each item of the disposable clothing in reducing bacterial dispersion. These tests demonstrated the relative ineffectiveness of wearing a surgical gown as compared with wearing the complete system. It was confirmed bacteriologically that the downflow system of ventilation was more efficient than the crossflow type; the importance of this observation with respect to clothing and sepsis is discussed in this paper.

Air Microbiology↗
PubMed1983

Surgery of the rheumatoid hip.

The incidence and pattern of involvement of the hip in rheumatoid arthritis are reviewed. The criteria for the selection of patients for surgery are described and the points in preparation emphasised. The surgical procedures available are discussed with the results and complications to be expected. The clinical results of total replacement arthroplasty are gratifying despite the increased incidence of infection and mechanical loosening compared with osteoarthritic hips.

Arthritis, Rheumatoid↗
PubMed1981

Biomechanical assessment of patients treated by joint surgery.

Surgical replacement of lower limb joints has been practised for twenty years although there is little quantitative information on loads transmitted either by implants or by other related joints. The results of tests are presented which evaluate the variation in external forces developed between the ground and foot during walking, together with the configuration of the lower limbs and the moments acting about the hips and knees. Two groups of patients were investigated; patients who were assessed prior to joint replacement and at intervals thereafter, and patients for whom the Girdlestone procedure was performed following a failed implant. The results area compared with those from similar tests on clinically normal subjects. There is a significant improvement post-operatively in the mechanical aspects of hip function for the replacement patients. The improvement continues after the first six months post-operatively and may result in abnormally high loading at other joints. At twelve months the performance of the patients with joint replacement differs significantly from the normal subjects and is generally better than the Girdlestone patients.

Biomechanical Phenomena↗
PubMed1978

Problems and pitfalls of compression fixation of long bone fractures: a review of results and complications.

The complications encountered in the compression fixation of 70 cortical long bone fractures are reviewed. The results represent the initial experience with the AO fixation equipment following its introduction to a centre with staff relatively untrained in the technique. Infection was the most serious complication, with a deep sepsis rate of 10.5 per cent, but fixation failure, delayed union and refracture also occurred. The various problems are discussed in detail and suggestions are made as to how they can be avoided.

Adolescent↗
PubMed1977

Influence of oxygen tension on somatomedin activity in vitro.

Somatomedins are the intermediaries through which growth hormone acts on the epiphyseal growth plate to effect linear skeletal growth. Rat epiphyseal chondrocytes were isolated and cultured in vitro in the presence of somatomedin. Two sources of somatomedin were used, foetal calf serum and rat liver perfusates. The chondrocytes proliferated and synthesized sulphated glycosaminoglycans when grown in the presence of somatomedin from either source, but were not metabolically active in chemically defined medium alone. Some differences in the growth patterns in response to serum or liver somatomedins are reported and discussed. Chondrocyte metabolic activity in the presence of somatomedin in vitro showed a graded response to alterations in the atmospheric oxygen, being greatest at low oxygen pressure, and almost completely inhibited at 95% oxygen. A gradient of local oxygen tension has been reported to exist across the epiphyseal plate in vivo. The effects of somatomedin combined with changing oxygen levels may help to explain the divergence of cell proliferation and matrix synthesis seen in the various regions of the growth plate.

Animals↗
PubMed1976

The effects of hyperoxia upon bone in organ culture.

Hyperoxia has been reported to stimulate both resorption and synthesis of bone in vitro. The effects of increased oxygen tension were re-investigated using calvaria from infant mice maintained in a stationary grid culture system for 48 48 hours with an unsupplemented chemically defined medium. Resting resorption due to osteoclastic activity was demonstrated in the explants in air by Von Kossa staining, histology, and 45 Ca release. Resorption was inhibited by exposure to 95 per cent oxygen or hyperbaric oxygenation at 2 atmospheres pressure. Hyperoxia also depressed new bone formatin by osteoblasts although the production of a new collagen, as measured by the incorporation of 3H-proline, was greater in calvaria cultured in hyperbaric oxygen than in paired explants in 95 per cent oxygen. Thus hyperoxia was toxic for both synthetic and resorptive activity of bone cells; these effects may stem from the loss of vital factors present in natural MEDIA supplements.

Animals↗