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Biomedical subjects

J T Scales

Publications and source records attributed to J T Scales.

At least 37 records · Page 2Linked to original sources
PubMed1981

Endoprosthetic replacement of the proximal femur and acetabulum. A survival analysis.

A series of 81 patients has been reviewed to determine the value of endoprosthetic replacement of the proximal femur and hip in the treatment of bone tumours. Standard statistical methods were used to evaluate the survival of the replacements and the patients. Taking removal of the prosthesis, irrespective of the cause, as the criterion for failure the survival of the replacements was found to be 63 per cent after 10 years. If deaths are regarded as failures, then the survival value falls to 48 per cent. The survival of patients with chondrosarcoma and osteoclastoma treated by endoprosthetic replacement compares favourably with survival after amputation or excision of the tumour.

Adolescent↗
PubMed1978

The Stanmore hinged knee arthroplasty.

The Stanmore hinged total knee replacement was introduced in 1969 for severe destructive arthropathy of the knee, and the results of one hundred consecutive operations are presented after an average interval of two and a half years. Insertion of the prosthesis relieved pain in 94 per cent, improved the range of movement in 67 per cent, invariably restored stability and corrected valgus or varus deformity. Gross flexion contractures were improved but not always fully corrected. Serious complications were few, though of three cases of deep infection two came to amputation and one to fibrous ankylosis. There were no mechanical failures of components of the prosthesis.

Aged↗
PubMed1975

Incidence of metal sensitivity in patients with total joint replacements.

Sensitivity to chromium, cobalt, nickel, molybdenum, vanadium, and titanium was studied by patch tests in 50 patients who had received total joint replacements. Nineteen (38%) were sensitive to one or more of the metals. In 23 patients non-traumatic failure of the prosthesis had occurred, and 15 of these patients were sensitive to metal. Out of 27 patients with no evidence of prosthesis loosening, four were sensitive to nickel and cobalt or nickel only. Dermatological reactions occurred in 13 patients after surgery; in only eight, however, was there evidence of metal sensitivity. These findings indicate that metal-on-metal total joint replacements may sensitise the patient to metals contained in the prosthesis. Although there is a high incidence of prosthesis failure among metal-sensitive patients it remains uncertain whether the loosening causes the sensitisation or vice versa.

Chromium↗
PubMed1975

Clinical considerations in the choice of materials for orthopedic internal prostheses.

The six principal clinical considerations which influence the choice of materials for total joint replacements are given. The necessity for screening tests on potentially useful materials is stressed. These should be carried out on specimens which have been exposed to the sterilizing process, which will be used in clinical practice. The materials should also be investigated after immersion in a physiological solution-bovine serum; following implantation in a large animal. Useful tests are impact testing, and wear studies using pin-on-disk and journal and bush specimens. In the case of total joint replacements, equipment in which joint motions and loadings can be simulated can provide valuable information. The components should also be subject to fatigue testing. There is a need to develop agreed laboratory methods for testing of materials and implants and for the long term follow up of patients.

Animals↗
PubMed1975

Excision of tumours of humerus and femur, with restoration by internal prostheses.

A personal experience is recounted of operations in cases of tumour involving the humerus or femur with restoration by endoprostheses. Twenty-four patients were treated in this way from 1950 to 1969 inclusive and have been followed up for between four and twenty-four years. The patients selected for treatment have presented chondrosarcoma (ten), so-called benign giant-cell tumour of bone, usually recurrent (nine), angiomatous osteolysis (two), seemingly single thyroid or renal metastasis (two), and ununited pathological fracture after irradiation of a tumour (one). Development of the prostheses from early beginnings is outlined. Some points in surgical management are referred to. The complications and results are recorded.

Adult↗