Congenitally corrected transposition of the great arteries: morphologic study of 32 cases.

The detailed anatomy of the heart is described in 32 autopsy cases of congenitally corrected transposition of the great arteries.Tis condition is defined as the combination of atrioventricular (A-V) discordance and transposition of the great arteries. Examples of primitive (single) ventricle with "inverted" (that is, left-sided in situs solitus) outlet chamber are excluded.

Carbon fiber-reinforced bone cement in orthopedic surgery.

A tougher, more fatigue-resistant bone cement consisting of short, highmodulus carbon fibers dispersed randomly in normal ply(methyl methacrylate) bone cement has been developed. Fatigue and impact tests are reported that demonstrate the superior fracture resistance and prolonged load-carrying ability of this system. The use of this carbon fiber-reinforced bone cement in the treatment of a pathological fracture of the femur associated with neoplastic disease of the bone is reported.

The bone-metal interface following hip nailing.

In order to establish a base line for tissue reaction in relationship to loaded implanted foreign materials that might be used for comparison with new materials, the interface between the trabecular bone in the femoral head and hip nails has been studied in 20 specimens. The interface consists of four distinguishable layers: a cellular layer at the surface, a layer of fibrovascular connective tissue, a layer of collagenous connective tissue and/or fibrocartilage, and a peri-implant bone plate. Even 10 years after insertion of the nail this interface remained cellularly active, the activity presumably being related to the different modulus of elasticity between the metal and the surrounding trabecular bone.

The femoral stem/cement interface in total hip replacement.

A study of the cement prosthesis interface has been carried out on the femoral component of 5 total hip relacements which had been in place between 7 weeks and 5 years. In every case a thin layer of connective tissue at varying stages of organization was present between the prosthesis and the cement. This suggests that the prosthesis is not rigidly fixed to the cement and is capable of micromovement.

The rate of bone ingrowth into porous metal.

Experiments have been devised to study the rate of ingrowth of bone into porous metal with pore sizes up to 100 mu and to study the significance of a gap between the porous metal surface and bone. When the porous coat was in direct apposition with bone, the implant was firmly locked in place after a three week period and the plateau value of implant-tissue shear strength was reached at four weeks. A gap of 1.

The significance of hepatitis B antigenaemia in symptom-free blood donors in Kenya.

One-hundred and eight blood donors found to have hepatitis B antigenaemia have been examined for evidence of liver disease. In five the liver was enlarged, and in six apparently normal donors there was histological evidence of disease. One or more tests of liver function were abnormal in an additional fifty-three donors without definite evidence of disease.

Observations on eburnated bone.

Eburnated bone in osteoarthritic joints has been examined with the Scanning Electron Microscope to investigate the cause of the bone loss which occurs at the joint surface in this condition. In eburnated bone the lamellae surrounding the Haversian canals can readily be seen. After artificial abrasion the surface is flat and featureless.

A radiologic sign of lateral subluxation of the distal tibial epiphyses.

Linear calcification of the interosseus membrane at the ankle in a juvenile who has sustained an eversion/abduction injury with otherwise normal radiographs indicates that a Type I injury has occurred to the distal tibial and fibular epiphyses, with displacement at the time of injury. This is a significant injury with the potential to cause growth arrest of the tibial epiphyseal plate.

Iatrogenic subcapital fracture of the hip: a new complication of intertrochanteric fractures.

A recently recognized complication of intertrochanteric fracture is a subcapital fracture occurring at the tip of the blade of an intertrochanteric fracture fixation blade plate. Histological examination reveals that this is not a fatigue fracture but is the result of stress concentration effects of a stiff metalic device. This fracture may be prevented by using a blade plate with a long blade which is well seated in the head, and by removing the metallic device as soon as it is safe to do so.

Trabecular stress fractures.

This study was conducted to evaluate the theory that increased rigidity in the subchondral cancellous bone and trabecular stress fractures are responsible for the development of osteoarthritis. Histological sections of the entire femoral head were examined in 80 normals, 50 cases with early degenerative changes, and 50 cases with advanced osteoarthritis. It was found that trabecular stress fractures occur normally and show no greater incidence in early osteoarthritis.

Use of polymethylmethacrylate to enhance screw fixation in bone.

Pull-out testing of screws inserted into cement and bone under various conditions showed that the cement-screw complex was significantly stronger when the screw was placed in soft cement and the cement was allowed to polymerize without further manipulation. When screw fixation in osteoporotic bone was reinforced with cement, the bone was the weakest component in the system. Fixation under these conditions should be enhanced by increasing the area of contact between the cement and bone.

Observations on osteoarthritis of the hip joint.

A correlation of the X-ray changes with the pathological changes seen in arthritic hips obtained at surgery or from cadavers, reveals 6 different patterns of osteoarthritis of the hip. The study suggests that the pathogenesis of the degenerative changes is different in each type and as such, would influence the results obtained by surgical intervention.

The microhardness of articular cartilage.

The standard metallurgical technique of microhardness testing was useful for investigations on the physical properties of articular cartilage. The problem of visco-elasticity of the cartilage was overcome by using a brittle lacquer coating as a memory device. The surface layer was the hardest plane when the superficial layer was intact.

Recovery of polysome function of T4-infected Escherichia coli after brief treatment with chloramphenicol and rifampin.

T4-infected Escherichia coli cells briefly exposed to rifampin, or to rifampin plus chloramphenicol, were capable of protein synthesis for some time after removal of the antibiotics, although ribonucleic acid synthesis was irreversibly inhibited. Partially completed peptides trapped on polysomes by high levels of chloramphenicol were eventually completed after removal of the drug, as demonstrated by subjecting labeled peptides from appropriate polysome regions to polyacrylamide disc gel electrophoresis. Thus, the effect of the drug appears to be reversible on the molecular as well as the cellular level.

Porous surface layered prosthetic devices.

The method of fabrication and properties of a dual structured implant system consisting of a metallic porous surface layer is described. The ingrowth of bone tissue into the outer porous surface layer results in part fixation, while the solid inner core region provides the necessary mechanical strength for a device used for the replacement of heavy load bearing joint regions such as the hip and knee. Additionally, novel implant systems are suggested using the porous coating concept.

Pyrophosphate arthropathy.

A scanning electron microscopic study of six cases of pyrophosphate arthropathy has been conducted. In the majority of cases the crystals were rectangular. In some cases giant crystals were present.

Tietze's disease.

The material from a case of Tietze's disease has been examined histologically. A review of the literature on the pathology of this lesion correlated with the findings from this case indicates that there is a pathological lesion in the costal cartilage in this disease. This consists of an increased vascularity and degenerative changes with patchy loss of ground substance leading to a fibrillar appearance.

Pathological fractures of the femoral neck.

In a review of subcapital fractures due to metastases in the femoral neck it was found that in the majority of cases pain in the region of the hip developed a few days prior to fracture. While the majority of subcapital fractures are sustained as the result of a single incident of trauma, in cases with metastases trabecular stress fractures occur in increasing numbers until finally femoral neck fracture occurs. It would seem that once a critical number of trabecular stress fractures has been reached the patient develops pain.