[Determination of the elasticity of the femoral cortex of Adam's arc in patients with osteoarthritis]

In this study, the compressive strength, the compressive force as well as cortical thickness of prismatic specimens from Adam's arc of the femur were determined in patients with osteoarthrosis. Correlations were evaluated between the cortical bone parameters, which depend on age and sex. Supported by histomorphometric data of cancellous bone, the great variability of mechanical properties revealed the variable osteological status prior to implantation of hip endoprostheses. Its eventual consequences for alloarthroplastic surgery had been discussed.

Quantitative study of articular cartilage and subchondral bone remodeling in the knee joint of dogs after strenuous running training

All tissues of the joint are affected in some way in osteoarthritis because the joint is an interactively functioning unit. Our goal was to investigate the combined responses of articular cartilage and subchondral bone to altered loading conditions to improve our understanding of the physiology of these two components and, ultimately, the pathophysiology of osteoarthritis. A group of 20 female beagle dogs were divided pairwise into runners (n = 10) and controls (n = 10). The running training on a treadmill started at the age of 15 weeks, and during the following 40 weeks the running distance was gradually increased to 40 km/day with a 15 degree uphill inclination. With this daily running distance the beagles ran another 15 weeks. The samples for histology were taken from 11 different locations of the knee joint. Subchondral bone and articular cartilage histomorphometry was carried out in three different regions of the specimens (central, middle, and peripheral regions) using an image-analyzing system and an eyepiece graticule. In all regions of the articular cartilage, both the uncalcified and calcified cartilage showed slightly increased thickness in the runner dogs. The change was more evident in the peripheral and the central areas. The thickness of the subchondral bone plate tended to be higher in runners, too. Bone histomorphometric parameters showed significant signs of increased remodeling. The most notable change was the enlargement of the bone formation surface. The most intense remodeling was usually observed either centrally or peripherally in the articular surface. The strongest increase in trabecular bone volume and thickness of the cartilage was recorded in the femoropatellar area.(ABSTRACT TRUNCATED AT 250 WORDS)

Osteologic standardization of human coxarthrosis using histomorphometry and its relevance for HIP alloarthroplasty

Using bone histomorphometry, in this study the osteologic status of 107 patients with coxarthrosis and femoral neck fracture [FNF] was assessed and compared with bone parameters from patients revised for aseptic loosening. Bone biopsies of the acetabulum and the proximal femur from patients with primary coxarthrosis [pCoxA] (69), dysplastic coxarthrosis [CDH] (19), rheumatoid arthritis [RA] (9), femoral head necrosis [FHN] (8), femoral neck fracture [FNF] (4) and aseptic loosening (12) were taken during hip alloarthroplastic surgery, prepared undecalcified and analysed using histomorphometry (according to MERZ). In pCoxA the following average figures of bone parameters of the acetabular biopsy were determined: trabecular bone volume (TBV) 39.6%, osteoid volume (OV) 3.9%, active osteoblastic surface (AOS) 6.5%, osteoclastic resorption surface (ORS) 2.4%, osteoid surface (OS) 17.4% and resorption surface (RS) 7.0%. As average figures of the femoral biopsy in pCoxA were assessed: TBV = 17.2%, OV = 1.3%, AOS = 0.9%, ORS = 0.4%, OS = 6.5% and RS = 2.5%. These data were compared with bone parameters of secondary coxarthrosis, osteoporosis (FNF) and aseptic loosening. Based on the study of Oettmeier et al. on femoral heads (Skel Radiol 18: 165-174, 1989), the investigated groups were subdivided into three osteologic types of the hip. The osteopenic type was found in 10% of pCoxA, 43% of RA and 28% of CDH. The hyperostotic type, predominantly occurring in males, was mostly demarcated in FHN (38%) and pCoxA (12%). The results demonstrate the individual osteologic status of patients before hip alloarthroplasty. This could influence planning of the operation and the bone-implant interface as well as long-term prognosis of artificial joints.

Osteoarthritis and bone: osteologic types of osteoarthritis of the hip

To assess prognosis and indications for allografting articular surfaces, osteological examination is of increasing importance. In this study 93 femoral heads of patients with primary osteoarthritis could be differentiated into three osteologic types using histomorphometry: (1) the osteosclerotic type (77% of cases), (2) the hyperostotic type, with excessive neogenesis of bone all over the femoral head and increased formation of osteophytes (10% of cases), and (3) the osteopenic type, with decreased bone mass and features of bone remodelling, a greater occurrence of subchondral cysts, and small osteophytes (8% of cases). Radiological and clinical features to distinguish these groups are given. The consequences for pathogenesis and clinical practice are discussed.