Comparative surface examinations on corund blasted titanium implants and explants in total hip arthroplasty.

Introduction: Blasting techniques using corundum to create rough surfaces are used in many different processes for the surface treatment of hip implants. Recent evidence points an association between residual particles and early loosenings in the sense of third-body wear.

Materials And Method: The surfaces of five unused, original-packaged CLS stems and ARR-Titan supporting rings, respectively, were compared with five explanted CLS stems and ARR-Titan supporting rings.

Range of motion in reconstruction situations following corpectomy in the lumbar spine: a question of bone mineral density?

Study Design: In vitro biomechanical study to evaluate the stability of different types of instrumentation in the lumbar spine following corpectomy in relation to bone mineral density (BMD).

Objectives: To investigate the relation between the stability of a spinal instrumentation and BMD. To determine a threshold value of BMD allowing a single ventral instrumentation following corpectomy in the lumbar spine.

Slow rebound of cancellous bone after mainly steroid-induced osteoporosis in ovariectomized sheep.

Objectives: A sheep model of osteoporosis suitable for implant testing for osteoporotic fractures was evaluated with regard to normalization of hormonal status and possible rebound of bone mineral density subsequent to the termination of steroid application.

Design: Osteoporosis was induced in 10 aged, female white alpine sheep. The sheep underwent ovariectomy, were kept in open, single-box husbandry, received a vitamin D(3) restricted diet, and a total dose of 2000 mg methylprednisolone (4 single doses of 500 mg at 3-week intervals).

Treatment strategies for proximal femur fractures in osteoporotic patients.

Fractures of the proximal end of the femur, together with vertebral fractures, are greatly exacerbated by osteoporosis and can be regarded as the most typical and most serious complications of this disease. The demand for prompt mobilisation with full loading of the affected limb, combined with a desire for the gentlest of treatments, becomes increasingly difficult to meet in ageing patients with advanced osteoporosis. The advantages of osteosynthesis in respect to these demands when operating on elderly patients with fractures do not apply due to the inability of the osteoporotic bone to hold the osteosynthetic components sufficiently until fracture healing occurs.

Effects of local application of growth and differentiation factor-5 (GDF-5) in a full-thickness cartilage defect model.

Our purpose in this study was to investigate the effects of growth and differentiation factor-5 (GDF-5) on cartilage and subchondral bone in a rabbit model harboring an osteochondral defect for a period of 6 months. Absorbable composites were implanted in adult rabbits (18 controls, 18 animals with collagen-I matrix, and 18 animals with matrix plus GDF-5). After 4, 8, or 24 weeks the specimens were studied by histology, microcomputed tomography (microCT) and flow-cytometric analysis (FACS).

Can novel clinical densitometric techniques replace or improve DXA in predicting bone strength in osteoporosis at the hip and other skeletal sites?

New peripheral techniques are now available for the diagnosis of osteoporosis, but their value in the clinical management of the disease remains controversial. This study tests the hypothesis that peripheral quantitative computed tomography (pQCT) at the distal radius and/or quantitative ultrasound (QUS) at the calcaneus can serve as replacement or improvement of current methodology (QCT and DXA) for predicting bone strength at the hip and other sites. In 126 human cadavers (age, 80.

Radius bone strength in bending, compression, and falling and its correlation with clinical densitometry at multiple sites.

This study comprehensively analyzes the ability of site-specific and nonsite-specific clinical densitometric techniques for predicting mechanical strength of the distal radius in different loading configurations. DXA of the distal forearm, spine, femur, and total body and peripheral quantitative computed tomography (pQCT) measurements of the distal radius (4, 20, and 33%) were obtained in situ (with soft tissues) in 129 cadavers, aged 80.16 +/- 9.

Bone strength at clinically relevant sites displays substantial heterogeneity and is best predicted from site-specific bone densitometry.

In this study we test the hypotheses that mechanical bone strength in elderly individuals displays substantial heterogeneity among clinically relevant skeletal sites, that ex situ dual-energy X-ray absorptiometry (DXA) provides better estimates of bone strength than in situ DXA, but that a site-specific approach of bone densitometry is nevertheless superior for optimal prediction of bone failure under in situ conditions. DXA measurements were obtained of the lumbar spine, the left femur, the left radius, and the total body in 110 human cadavers (age, 80.6 +/- 10.