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Biomedical subjects

H U Cameron

Publications and source records attributed to H U Cameron.

161 records · Page 9Linked to original sources
PubMedDate not supplied

Fine detail radiography of the femoral head in osteoarthritis.

In an effort to define the relationship of articular cartilage to subchondral bond in osteoarthritis, fine detail radiography of over 600 femoral heads were examined. In general, cartilage loss was paralleled by subchondral bone thickening, but this was not a uniform finding. In the inferomedial part of the femoral head, thickening of the subchondral bone plate never occurred. If the cartilage thickening in this area exceeded 2 mm then a new subchondral bone plate was formed.

Calcinosis↗
PubMedDate not supplied

Symmetrical muscle contractures in tumorous sarcoidosis: report of a case.

A 25-year-old woman had symmetrical contractures of the gastrocnemii with a large firm swelling in both medial heads. The contractures insidiously increased over the previous six months. Roentgenograms of the chest showed hilar lymphadenopathy but investigations were otherwise negative. Biopsy showed this to be tumorous sarcoidosis. Both tendoachilles were lengthened. Spontaneous regression of the abnormal muscle masses subsequently occurred without further treatment. Tumorous sarcoidosis is a rare entity, and there have been very few previous reports of muscle contractures having occurred associated with sarcoidosis.

Achilles Tendon↗
PubMedDate not supplied

Cemented double cup arthroplasty of the hip: a 5 year experience with the ICLH prosthesis.

The ICLH (Imperial College-London Hospital) total hip arthroplasty is a procedure in which a metal femoral component caps the proximal femur and a polyethylene acetabular component resurfaces the acetabulum with both components cemented in place. Between June, 1972, and November, 1974, changes were made in prosthetic design and in operative technique in response to 2 specific problems encountered. The loosening rate was high until the original polyethylene femoral component was redesigned so that it was metal. The incidence of femoral neck fractures was unacceptable until trochanteric osteotomy was discontinued. Since November, 1974, 116 hips have been replaced and neither the prosthesis nor the operative technique has changed. Pain relief has been comparable to that obtained with conventional Charnley-type hip replacement. All patients walk out of doors and no patient's walking capacity is limited by pain in the operated hip. No hip has lost motion and 36% have an effectively full range. No deterioration in the quality of these results is suggested when the first postoperative assessment is compared to those at 2 years and longer postoperative. Technical errors to be recognized and avoided are varus placement of the femoral component and excessive vertical placement of the acetabular component.

Aged↗
PubMedDate not supplied

Retention of the compression screw in sliding screw plate devices.

Distraction forces at the site of an unstable intertrochanteric fracture can cause disengagement of the sliding hip screw from the barrel of the side plate. If such a device is used for unstable comminuted intertrochanteric fractures, the compression screw should be retained.

Aged↗
PubMedDate not supplied

A correlation of radiographic "modes of failure" with clinical failure of cemented stem-type femoral components.

Four modes of failure of cemented stem type femoral components are: pistoning within the medullary canal (mode I); medial migration of the proximal stem and lateral migration of the distal stem (mode II); medial lateral toggle of the distal stem tip (mode III); loss of proximal support with firm fixation of the distal end (mode IV). These radiographic failure patterns have been correlated with clinical findings at revision of 51 loose femoral components. The findings at revision correlated well with the radiographic findings indicating the accuracy of this nomenclature, which simplifies discussion of stem failures. Mode I was found to be the most common, and mode IV the most difficult to revise. Neither age, nor weight nor surgical approach influenced the failure mode. The overall results of revision were poor, with most hips rapidly assuming a IB type of appearance.

Bacterial Infections↗
PubMedDate not supplied

The optimum pore size for the fixation of porous-surfaced metal implants by the ingrowth of bone.

For a study on the effects of pore size variation on the rate of bone growth into porous-surfaced metallic implants and on the strength of fixation resulting from this ingrowth, 4 distinct pore size ranges were prepared on cobalt-base alloy implants with cobalt-base alloy powder particles of different dimensions. The porous implants were placed into canine femurs for periods of 4, 8, and 12 weeks. Mechanical tests were performed to measure the shear strength of fixation of the implants to cortical bone. For implants with powder-made porous surfaces, a pore size range of approximately 50 to 400 microns provided the optimum or maximum fixation strength (17 MPa) in the shortest time period (8 weeks).

Animals↗
PubMedDate not supplied

Internal fixation of slipped femoral capital epiphyses.

The problems related to internal fixation for the treatment of slipped femoral capital epiphyses were reviewed in 164 cases and by a questionnaire of 59 orthopedic surgeons. Significant problems were reported with all fixation devices. With Trifin nails, the main difficulty was getting them to stay in in place. With threaded pins, there was difficulty removing them. The best fixation was obtained with the cast Vitallium Knowles pin, but it requires additional modification and improvement.

Bone Nails↗
PubMedDate not supplied

Acquired valgus instability after knee replacement.

Four cases of acquired valgus instability occurred after knee resurfacing operations; all four were initially stable. Three cases originally had a varus deformity which required extensive releases for its correction. All of these patients fell, disrupting the medial joint capsule and medial collateral ligament. This complication in the two early cases could have been prevented by adequate bracing until full recovery of the quadriceps had occurred. In one case, attribution due to projection medially of the tibial component may have played a role. In the fourth case, the tibial component was inserted with the tibia in external rotation, thus advancing the tibial attachment of the medial collateral ligament, which was disrupted during manipulation to gain flexion. The simplest treatment for this complication is probably to brace the knee until the joint reaction settles and then revise to a fully constrained prosthesis.

Aged↗