Periosteal chondroma of the humerus leading to shortening. A case report.

We report a case of periosteal chondroma of the proximal humerus with multiple cartilaginous masses extending around two-thirds of the metaphysial circumference. The humerus was short, presumably because the tumour interfered with growth at the epiphysial plate

Lymphangiomatosis of the arm with massive osteolysis. A case report.

A case of massive osteolysis of the arm is described where the typical bony lesions were associated with soft tissue lymphangiomatosis

Chondrodystrophic dwarfism and multiple malformations in two sisters.

A genetic skeletal dysplasia with dwarfism, scoliosis and multiple skeletal defects was observed in two sisters. Only nine cases with similar features have been reported in the literature

The reaction to nailing or cementing of the femur in rats. A microangiographic and fluorescence study.

Bone reaction to cement and to a cementless stem was studied in the rat femur with histological fluorescence and microangiographic techniques. Periosteal and endosteal apposition, and consequent remodelling, appeared as a reaction to reaming rather than caused by cement or a cementless stem. Every change in bone began with proliferation, progression and orientation of the vessels. Endosteal apposition was absent in cemented femurs because the entire medulla was occupied by the acrylic cement, but remodelling of the subendosteal cortex followed medullary revascularisation which was far advanced after 90 days. In cementless stems, endosteal apposition of primary woven bone and remodelling was the basis for bony ingrowth and anchorage through bony bridges. Our results suggest that the pattern of blood supply is relevant to the structural organisation of mature lamellar bone around the implant. Cemented stems have maximum anchorage and stability as soon as they are inserted, but this decreases with time as revascularisation occurs. Cementless stems can reach maximum integration later after insertion, and revascularisation is less critical because they usually do not fill the canal completely

The effects of mechanical forces on bones and joints. Experimental study on the rat tail.

We have used an experimental model employing the bent tail of rats to investigate the effects of mechanical forces on bones and joints. Mechanical strain could be applied to the bones and joints of the tail without direct surgical exposure or the application of pins and wires. The intervertebral disc showed stretched annular lamellae on the convex side, while the annulus fibrosus on the concave side was pinched between the inner corners of the vertebral epiphysis. In young rats with an active growth plate, a transverse fissure appeared at the level of the hypertrophic cell layer or the primary metaphyseal trabecular zone. Metaphyseal and epiphyseal trabeculae on the compressed side were thicker and more dense than those of the distracted part of the vertebra. In growing animals, morphometric analysis of hemiepiphyseal and hemimetaphyseal areas, and the corresponding trabecular bone density, showed significant differences between the compressed and distracted sides. No differences were observed in adult rats. We found no significant differences in osteoclast number between compressed and distracted sides in either age group. Our results provide quantitative evidence of the working of 'Wolff's law'. The differences in trabecular density are examples of remodelling by osteoclasts and osteoblasts; our finding of no significant difference in osteoclast numbers between the hemiepiphyses in the experimental and control groups suggests that the response of living bone to altered strain is mediated by osteoblasts

Fracture with loss of the proximal femur in a child. A case report.

An 8 year old child was involved in a road accident and sustained a large wound in the left groin; radiographs showed a fracture with loss of the proximal femur. After skeletal traction for 80 days, there was bony regeneration of the proximal femur. At 8 months she was able to walk without support and her left leg was 2 cm only shorter than the right

Metal determination in organic fluids of patients with stainless steel hip arthroplasty.

In 20 stainless steel Charnley hip arthroplasties (with a follow-up of 10-13 years) nickel, chromium and manganese levels were measured in blood, plasma and urine by atomic absorption spectrophotometry. Skin patch tests for these metals, and clinical and roentgenographic results of arthroplasty were also assessed. Metal levels in organic fluids were plotted against a control population homogene- ous for age, residence and anamnestic conditions with the first, but which had never undergone a prosthesis or other metallic implant surgical procedure. Nickel levels in blood, plasma and urine, manganese levels in blood and urine and chromium levels in plasma were significantly higher in the hip prostheses popula- tion. Metal ion release from stainless steel prostheses is discussed with regard to implant failure, metal sensitivity and carcinogenesis

Failure of the stem in total hip replacement. A study of aetiology and mechanism of failure in 13 cases.

Thirteen failed stem of Total Hip Replacement were studied: 9 were Charnley THR from an homogeneous series, which gives an incidence of 2.4% of stem fractures with a follow-up of 9-16 years; 4 were Mueller THR. Fatigue fracture of the stem occurred by defective support of the proximal part of the femur, following resorption of the calcar. In all cases reactive tissue to foreign body particles, metal and polyethylene, was found where bone resorption occurred. In Mueller THR wear of the cup produced the large amount of polyethylene particles; in Charnley THR metal particles prevailed and corrosion of the stem is suggested to be the initiating factor

Involvement of metal particles in loosening of metal-plastic total hip prostheses.

Four loosened metal-on-plastic total hip prostheses and associated tissues were examined. Each implant showed an uncommonly high formation of metal particles produced by wear or corrosion of the femoral stem. The granulation tissue between bone and cement was characterized by macrophages containing metal particles. Histological, histochemical, and ultrastructural investigations have been performed to assess cellular reactions to ingested metal particles. Pathogenesis of loosening in these cases is discussed in relation to the role of macrophages in bone resorption

Trajectories across the healthy adult lifespan on sense of direction, spatial anxiety, and attitude in exploring places

Introduction: Self-evaluations about orientation and navigation in the environment contribute to individual differences in spatial cognition. Evidence suggests that they may change, even slightly, with the progression of adulthood. It is necessary to improve the framing of environment-related subjective self-evaluations in adulthood and aging by examining how they change and the factors related to them. Therefore, this study aimed to examine the developmental trajectories of sense of direction, spatial anxiety, and attitude in exploring place across the adult lifespan while also considering gender and education. Materials and methods: A sample of 1,946 participants (1,068 women), aged 18–87 years, completed the sense of direction and spatial representation, spatial anxiety, and attitude in exploring scales. Results: The regression models showed a linear increase in sense of direction with age, stable spatial anxiety until age 66 years when anxiety began increasing, and a stable attitude in exploring with a deflection by age 71 years. Gender played a role in all three types of self-evaluations, with men reporting higher ratings in sense of direction and attitude toward exploring (especially in older men), and lower levels of spatial anxiety than women did. Education also played a role, with higher education years associated with lower ratings in spatial anxiety and a higher sense of direction, nullifying gender differences in the latter. Discussion: These results offer, in the spatial cognition framework, a better understanding of how specific environment-related self-evaluations develop with age and related factors, such as education. This underscores the importance of enhancing them, particularly in women and older adults