Osteoarthritis of the hip. Possible protective and causative roles of trabecular microfractures in the head of the femur.

In contrast to the large volume of data on the cartilage and synovial fluid changes, there has been relatively little investigation of the involvement of bone in the genesis of osteoarthritis (OA). Previous researchers have hypothesized that OA follows stiffening of subchondral bone through trabecular microfractures. Although it is widely recognized that marked changes in the subchondral bone are a consistent feature of advanced OA, the nature of the changes in the bone in OA has not received significant attention. The heads of the femur from 67 patients who had joint replacement for advanced OA and 66 autopsy controls without discernible joint disease were examined microscopically to ascertain the number and distribution of trabecular microfractures in coronal slabs and to quantify the mineralization and thickness of trabecular bone in a principal compressive zone. There was a reduction in the number of trabecular microfractures in OA patients, compared with the controls, with a lack of correlation between numbers of microfractures and age in OA patients. There was no evidence for the hypothesis that increased numbers of microfractures led to the increase of bone to support the view that microfractures play a role in maintaining OA joint structure. Structural changes produced relatively sclerotic and porotic groups of OA and two subgroups of the sclerotic group.

Histomorphometric changes in the trabecular structure of a selected stress region in the femur in patients with osteoarthritis and fracture of the femoral neck.

Histomorphometric changes in the trabecular structure of the principal compressive stress region in the femur in patients with osteoarthritis and fracture of the femoral neck are described. Femoral heads were obtained from patients who had surgery for the treatment of femoral neck fracture or total hip replacement for advanced osteoarthritis. Blocks from the principal compressive region of a coronal slice were sampled systematically to prepare 10 microns sections for automated analysis. There was no significant difference in the mineral bone content of the osteoarthritic (OA) and fractured neck of femur (FNOF) cases or between males and females for each group. The regression of mineralized bone on age was significant for OA data, showing a decrease in mineralized bone volume with age, whereas there was no significant relationship for the FNOF data. Surface density was significantly lower in the OA group than in the FNOF group despite the fact there is no difference in the mineralized bone. The regression of surface density on age was not statistically significant in both groups, although regression of surface density on the mineralized bone was significant for both groups and demonstrated that OA cases generated less surface than FNOF cases for the same amount of mineralized bone volume. The trabeculae in OA were significantly thicker than in FNOF, and spacing in OA was significantly greater than in FNOF. The regression of trabecular thickness and spacing on age was not significant for either OA or FNOF. For OA, thickness and spacing showed a significant regression on the mineralized bone volume, positive and negative, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

A quantitative description of selected stress regions of cancellous bone in the head of the femur using automatic image analysis.

This study was carried out to describe in quantitative terms histologic parameters from selected regions of the cancellous bone in the normal femoral head. Femoral heads were obtained at autopsy, and blocks from the principal compressive (PC) and principal tensile (PT) regions of a coronal slide were sampled systematically to prepare 10 microns sections for automated histoquantitation using a Quantimet image analyzer. For mineralized bone there was a significant negative regression on age in both principal stress regions, though the quantitative description was not definitive. The principal compressive values of mineralized bone were higher, with no sex difference, compared to the principal tensile values, which showed a sex difference. Changes in trabecular surface, width, and marrow spacing were shown to be more dependent on bone mass than on age. The surface density values were higher, without sex difference for the PC region compared to the PT region, which had a sex difference. There was no regression on age for the PC region but a significant negative regression for the PT region. For mean trabecular thickness, again the values were higher for the PC region, with negative regressions on age for both regions but no sex difference in either region. For spacing, the values were lower for the PC region, with a significant increase with age for both regions but no sex difference in either region. The surface density had positive linear regressions on mineralized bone for both PC and PT regions, though a parabolic regression, based on a model described, was favored.(ABSTRACT TRUNCATED AT 250 WORDS)

Ulnar neuropathies in rheumatoid arthritis.

A loss of functional motor axons in the median and ulnar nerves occurred in half of thirty-three patients with rheumatoid arthritis. Weakness of small hand muscles may predispose to the development of ulnar deviation of the fingers in patients with joint disease at the radio-ulnar and metacarpophalangeal joints. There is no evidence that spasm of small hand muscles is a significant cause of ulnar deviation of the fingers in rheumatoid arthritis. Ulnar deviation of the fingers in rheumatoid arthritis is not due to selective impairment of the ulnar nerve or the deep palmar branch of the ulnar nerve even though ulnar deviation of the fingers can occur in association with such lesions and in the absence of joint disease.

Yttrium-90 citrate colloid for radioisotope synovectomy.

The preparation of an yttrium-90 citrate colloid is described. This formulation localizes in the synovial membrane and thereby eliminates any irradiation received by extra-articular tissues. Yttrium-90 is eluted from Sr-90 bound to a sulphonic acid ion exchange resin. The colloid is prepared using a 3:1 ratio of carrier yttrium and citrate. Contamination with ionic 90Y and ionic 90Sr was less than 1 percent and 0.001 percent, respectively. In the 28 patients studied, all of the injected dose of 90Y remained in the region of the joint. Brief clinical results are presented.