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Biomedical subjects

R C Todd

Publications and source records attributed to R C Todd.

At least 19 recordsLinked to original sources
PubMed2003

Brachytherapy tubes and free tissue transfer after soft tissue sarcoma resection.

Irradiation commonly is used after resection of soft tissue sarcomas to decrease the local recurrence rate. Brachytherapy spares more normal tissue than external beam irradiation and permits irradiation to the tumor bed in the immediate postoperative period. After vascular anastomosis and irradiation, flap survival can be affected by vascular coagulation in the immediate postoperative period and later by vascular fibrosis secondary to irradiation effects. The purpose of the current retrospective study was to evaluate the survival of free tissue transfer when combined with brachytherapy after resection of soft tissue sarcomas. Thirty-six patients had wide resection of extremity tumors, free flap coverage, and brachytherapy 5 days after surgery. Followup averaged 54 months. There were three major and four minor complications. The major complications included two patients with free flaps who required revision of anastomosis before radiation therapy (they had brachytherapy 5 days after the second surgery without additional complications) and one patient who had a deep wound infection develop 2 months after the index procedure and required a second flap. Minor complications included one hematoma, one partial skin graft loss, and two superficial infections. Brachytherapy can be done safely at the site of microvascular anastomosis in the immediate postoperative period.

Adolescent↗
PubMed1997

Uptake of 99mTc-MDP after uncemented hip arthroplasty: a quantitative analysis of findings around the femoral component in asymptomatic patients.

We studied the pattern of 99mTc-methylene diphosphonate uptake around uncemented femoral components in 44 asymptomatic hip arthroplasties, performing isotope scans at intervals from 4 to 48 months after operation. We used phase-II images obtained with a high-resolution gamma camera and measured the activity in various zones using a specially designed computer program. The components studied at 4, 6, 9 and 12 months were coated with hydroxyapatite (HA) and those studied at 18, 24, 36 and 48 months were not coated. We found a statistically significant fall in activity between four and six months around HA-coated prostheses in all five femoral periprosthetic zones. After six months activity was relatively uniform, but remained higher than that in normal femoral bone at 48 months in non-coated prostheses. We discuss the application of these patterns in the evaluation of painful cementless hip arthroplasties.

Adult↗
PubMed1994

Quantitative bone scanning after asymptomatic Charnley arthroplasty.

To establish the normal pattern of postoperative tracer uptake we performed 73 99mtechnetium methylene diphosphonate scans following primary Charnley hip replacements for arthrosis in 68 patients without clinical, hematological and radiographic complications. The patients were divided into 7 subgroups according to the period, 6-24 months, between surgery and scan. There were 10-12 patients in each subgroup. A high-resolution gamma camera with a large field of view was used. Ratios of uptake in each of 10 peri-prosthetic zones to normal bone were calculated. Femoral uptake was found to decrease in linear fashion from 6 to 12 months after surgery. Thereafter the uptake remained unaltered at levels nearly twice the normal ones in the greater trochanter and nearly 1.5 times in the lesser trochanter, returning to almost normal levels in other zones. Acetabular uptake remained elevated throughout.

Acetabulum↗
PubMed1990

Prophylactic pinning in slipped upper femoral epiphysis. Prevention of complications.

We report the complications of prophylactic pinning of slipped upper femoral epiphysis with Crawford Adams pins in 95 cases. Complications of pin placement were seen in 13.7%. Although seven hips had penetration of the joint, there were no cases of chondrolysis or avascular necrosis. Excavation of the lateral femoral cortex was required at pin removal in 12.5% of cases. Analysis of the growth around pins allowed recommendations to be made regarding pin protrusion. The use of improved fixation devices may reduce the need for multiple pins.

Adolescent↗
PubMed1988

Open reduction of the severely slipped upper femoral epiphysis.

The results of open reduction of the severely slipped upper femoral epiphysis are reported for 115 hips with an average follow-up of 12 years 11 months (range 2 to 33 years). In 70 hips with a chronic slip and an open growth plate the incidence of complications was low: two developed avascular necrosis, five chondrolysis, and one had both. There were more complications in the 38 hips with an acute-on-chronic slip: six developed avascular necrosis, one chondrolysis, and three had both. Of the seven hips operated upon with a partially fused plate, only one did well. All these complications were obvious within the first year but there were also three hips in the series in which osteoarthritis developed between 10 and 20 years after operation.

Adolescent↗
PubMed1985

Stemmed revision arthroplasty for aseptic loosening of total knee replacement.

Fifty-three failed knee replacements were revised using minimally constrained implants with smooth uncemented intramedullary stems and metal-backed tibial components. Polymethylmethacrylate was used only to replace lost bone near the surface of the implant. Excluding four knees which had serious postoperative complications, 91% had successful relief of pain, 84% had over 90 degrees of movement and 80% could walk for more than 30 minutes. Review of the radiographs showed that there were no progressive lucencies at the interface between bone and cement, and no subsidence of components or changes in alignment. At the uncemented stem-to-bone interface, thin white lines developed near the metal, and their significance is discussed. This revision technique is an effective treatment for aseptic failure of primary total knee arthroplasty.

Adult↗
PubMed1978

ICLH arthroplasty of the knee: 1968--1977.

The essentially satisfactory results from the ICLH implant as used until 1975 were marred by examples of loosening and sinking of the tibial implant, by patellar pain of varying severity, by wear of the tibial implant caused by fragments of cement and by failure consistently to control the alignment of the leg. This report describes the methods now being used to overcome these complications and gives an account of the success so far achieved.

Arthroplasty↗
PubMed1977

Replacement of the severely damaged arthritic knee by the ICLH (Freeman-Swanson) arthroplasty.

A multi-centre clinical trial of ICLH (Freeman-Swanson) arthroplasty has been in progress since 1971. In this paper the results up to two years after operation are reported in seventy-one knees displaying at least 30 degrees of fixed flexion, 25 degrees of valgus or 20 degrees of varus, before operation. It has been found that knees displaying 70 degrees of fixed flexion, 70 degrees of valgus, 30 degrees of varus or 50 degrees of valgus/varus instability can be satisfactorily aligned and stabilised with acceptable function. Three knees required revision. The other complications are listed and were unremarkable in nature. These results depend upon the prosthesis and upon the operative technique. The latter avoids damage to healthy bone but does involve the replacement of the tissues in the midline of the knee.

Adult↗
PubMed1977

A techinque for recording the results of knee surgery.

A research form for recording clinical data relating to the arthritic knee is described. Data are recorded using a numerical code which facilitates transfer to a computer and provides an easily read record. Any form must be a compromise but the one described has been proven clinically by providing the data for a multi-center evaluation of hundreds of knees observed over a period of 5 years. A shorter form is described for routine follow-up purposes.

Arthritis↗
PubMed1977

The presentation of the results of knee surgery.

A method is described by which the detailed results of knee surgery may be presented in a compact, readily understood and easily analyzable fashion. The data can be analyzed and presented either manually or by a computer and if the latter is used no special print-out equipment is required. The success of the method has been proved over a 5-year period in the monitoring of the results of a multi-institutional investigation of total knee arthroplasty.

Arthroplasty↗
PubMed1976

Hyaluronidase-bound membrane as a biomaterial for implantable fuel cells.

A new biomaterial containing covalently bound hyaluronidase was prepared. An application of this enzyme membrane is to improve the performance of an implantable fuel cell. Hyaluronic acid is a contributor to the viscosity of tissue fluids but can be a potential fuel source because of its sugar content. The incorporation of immobilized hyaluronidase would not only contribute to a more available fuel supply by splitting hyaluronic acid but, perhaps more importantly, enhance the rate of mass transport of fuel, O2, and reaction products by reducing the viscosity near the electrode membranes. Hyaluronidase was bound to Sepharose gel and its thermoplastic membrane after activation by cyanogen bromide. Fourteen and 22% of the activities were recovered from the gel and membrane, respectively. The activity of the bound enzyme was stable for six months at 0 degrees C. The addition of hyaluronic acid, 1 mg/ml, to a typical implantable type bioautofuel cell in vitro increased external solution viscosity from 1.1 to 2.5-2.8 cP and reduced voltage output under 10 komega by 60% in 3 hr. When the hyaluronidase bound membrane was placed at the anode, viscosity of the glucose-hyaluronic acid solution was lowered to 1.8 cP and the cell output increased to the original level of a glucose-fueled cell in 3 hr. Glucosamine-equivalent released from hyaluronic acid at the electrode was 3.1 mg after 22.5 hr. This represents 90% of the theoretical consumption. Restoration of the cell output was probably a combination of the enhanced transport of fuel, O2 and products, and/or appearance of a new fuel, glucosamine-equivalent.

Biocompatible Materials↗
PubMed1976

ICLH (Freeman/Swanson) arthroplasty in the treatment of arthritic knee: a 2 to 4-year review.

A prospective follow-up using a standardized data recording form was carried out by independent, experienced orthopedic surgeons on a small number (116) of knees operated upon at The London Hospital in the period January 1, 1971 to October 31, 1973. An additional 93 knees have been operated upon at other hospitals and followed prospectively using the same data recording system. A total of 159 knees have been reviewed 2 to 4 years after operation. The complications specific to ICLH arthroplasty have been unremarkable and generally correctable. Two tibial components have sunk and have been revised at The London Hospital. The results show that ICLH arthroplasty has been used to correct satisfactorily flexion deformities up to 70 degrees, valgus deformities up to 45 degrees, and varus deformities up to 35 degrees. (Deformities of greater magnitude can be corrected but were not present among the knees in this study.) The operation may be said to be "worthwhile" with reference to pain in 94 per cent of the knees, with reference to the ability to walk in 80 per cent of the knees, and with reference to the range of movement in 71 per cent. Overall, 47 per cent of the knees had no complaint postoperatively, while a further 47 per cent were improved; thus for 94 per cent the procedure was "worthwhile."

Adult↗