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Biomedical subjects

E R Bogoch

Publications and source records attributed to E R Bogoch.

At least 19 recordsLinked to original sources
PubMed1998

Fractal dimension as a measure of altered trabecular bone in experimental inflammatory arthritis.

Our previous studies in experimental inflammatory arthritis (EIA) and in human rheumatoid arthritis demonstrated rapid remodeling with a 5-fold increase in bone resorption and bone formation. Normal condylar trabecular bone is typically anisotropic, with its orientation along lines of stress; rapid remodeling in a pathological state could disturb the usual order of trabeculae. This study assessed change in the structure of trabecular bone of the distal femoral epiphysis after induction of EIA, using a measure of "fractal dimension," which may be considered a quantitative description of the degree of irregularity of complex surfaces. Data was obtained from specimens in which EIA had been induced in the rabbit knee by 10 injections of carrageenan over 49 days. Photographic enlargements of embedded undecalcified cross-sections of the distal femur were digitized, and software written on a Sun workstation was used to define repeatable regions of interest (ROIs) in the images. The ROIs were subjected to fractal analysis by a power law method. The fractal dimension of the trabecular bone pattern within the ROI was estimated by fitting an equation of the form A (epsilon) = lambda epsilon (2-D) to the data. In this equation, A (epsilon) is the area of the "surface" formed by modeling the ROI data as a three-dimensional structure with the grey-level magnitude providing the third dimension, lambda is a scaling constant, epsilon is the size of the measuring "tool" used to measure the area, and D is the fractal dimension. A Mann-Whitney U-test applied to the average of the data from all ROIs showed that the two distributions of fractal dimension were significantly different (p < 0.005). There were only two overlaps between data points for arthritis (with these values higher) and normal groups (n = 11 for each group). Since Howship's lacunae were too small to be resolved in the system utilized, we consider the difference in fractal dimension to be primarily related to trabecular surface orientation, rather than to the increased number of asperities (resorptive foci) occurring due to increased turnover in bone affected by inflammatory arthritis. The results suggest that fractal dimension may be a useful tool for assessing the degree of structural damage to trabeculae in conditions similar to EIA.

Animals↗
PubMed1998

Musculoskeletal surgery in psoriatic arthritis.

OBJECTIVE: To determine the probability that patients with psoriatic arthritis (PsA) will require musculoskeletal surgery. To identify factors predictive of surgery in patients with PsA. To determine the clinical outcome of patients with PsA who underwent surgery compared to patients who did not. METHODS: The database of the Psoriatic Arthritis Clinic was searched to identify individuals who had undergone musculoskeletal surgery. Biological and clinical data such as erythrocyte sedimentation rate (ESR), rheumatoid factor, clinical pattern, nail changes, functional class, number of inflamed joints, and radiological damage, as well as health scores such as Arthritis Impact Measurement Scale 2 (AIMS-2), SF-36, and Health Assessment Questionnaire (HAQ) were available for these patients. Patients who had surgery were compared to those who did not. RESULTS: Out of 444 patients with confirmed PsA, 31 had musculoskeletal surgery (6.98%). This probability increased with the duration of PsA. Surgery patients had their first operation at an average of 13.9 years (range 1-46) after onset of joint disease. Age at onset of PsA, clinical pattern, constancy of clinical pattern over time, rheumatoid factor, functional class, symmetry, nail changes, and the time separating the onset of skin disease and the onset of joint disease were not significantly different at the 0.05 confidence level. Patients who had surgery had significantly more radiological damage (p < 0.001) and more actively inflamed joints (p < 0.02) at first assessment than patients who did not. AIMS2, SF-36, and HAQ scores at final review were not statistically different across both groups. CONCLUSION: In our patients the probability of having musculoskeletal surgery for PsA was 7%. It increased with disease duration. Patients had their first surgery after an average of 13 years. The number of actively inflamed joints and the extent of radiological damage at first assessment were highly predictive of subsequent surgery: patients with the highest numbers of severely affected joints, both clinically and radiologically, were more likely to have surgery. "Baseline characteristics" such as ESR, rheumatoid factor, functional class, clinical pattern, nail changes, and symmetry were not predictive of subsequent orthopedic surgery.

Adult↗
PubMed1998

Abnormal bone remodelling in inflammatory arthritis.

Osteopenia is responsible for substantial comorbidity in patients suffering from rheumatoid arthritis and is an important factor in the surgical management of joint disease. In animal models of bone loss stimulated by inflammatory arthritis, increased bone remodelling and altered microstructure of bone have been documented. The subchondral bone plate near the joint surface is narrow and perforated by vascular inflammatory invasion, and in the shaft the thin cortices are weakened by giant resorption defects. Biomechanical tests and a mathematical model of bone strength suggest that cortical defects, much larger than those found in normal osteonal remodelling, are principally responsible for the experimentally observed loss of strength. Similarly, these defects may explain the increased femoral fracture risk in rheumatoid arthritis. The osteoclast, the cell resorbing bone, is demonstrated in increased number and activity in rheumatoid arthritis and in animal models. Bisphosphonates, drugs that inhibit osteoclast function, have been shown experimentally to reduce both focal and generalized osteopenia and to prevent loss of bone strength. Bisphosphonates also protect articular cartilage from damage characteristic of inflammatory arthritis. The mechanism of chondroprotection may be prevention of subchondral bone resorption by the osteoclast and also an altered distribution of bone marrow cells. Thus, bisphosphonates, currently in clinical use for other bone metabolic diseases, appear to have potential as prophylaxis and treatment for osteopenia and joint damage in inflammatory arthritis.

Animals↗
PubMed1997

Rheumatoid arthritis synovial fibroblast and U937 macrophage/monocyte cell line interaction in cartilage degradation.

OBJECTIVE: To examine the interaction between synovial fibroblasts and macrophages in the context of cartilage degradation. METHODS: An in vitro model of human cartilage degradation was used, in which purified populations of fibroblasts and macrophages were added to a radiolabeled cartilage disc. Cartilage destruction was measured by the percentage of radiolabel release. RESULTS: Fibroblasts, obtained from either rheumatoid arthritis (RA) or osteoarthritis synovial tissue, could mediate cartilage degradation if cocultured with the U937 macrophage cell line. Skin and RA bone marrow fibroblasts had no degradative effect on cartilage. Fibroblast-macrophage contact was not required for cartilage degradation. Cartilage degradation by synovial fibroblasts was inhibited by antibodies to tumor necrosis factor alpha (TNF alpha), interleukin-1 beta (IL-1 beta), and IL-6. Cartilage degradation was almost completely abrogated by a combination of antibodies to TNF alpha and IL-1 beta. Contact between fibroblasts and cartilage was shown to be essential. Antibodies to CD44, but not to intercellular adhesion molecule 1, markedly inhibited cartilage degradation. CONCLUSION: TNF alpha, IL-1 beta, and IL-6 were involved in the activation of synovial fibroblasts to cause cartilage degradation. Cartilage degradation occurred only when fibroblasts were in contact with cartilage. CD44 was demonstrated to be involved in the fibroblast-cartilage interaction.

Antibodies↗
PubMed1997

Zoledronate (CGP 42'446), a bisphosphonate, protects against metaphyseal intracortical defects in experimental inflammatory arthritis.

This study investigated zoledronate (CGP 42'446), a bisphosphonate, as a potential prophylactic and therapeutic agent against intracortical defects in metaphyseal bone in an experimental model of inflammatory arthritis. Inflammatory arthritis was induced in the right tibiofemoral joint of rabbits by the repeated injection of carrageenan. Three groups of animals were treated with the bisphosphonate daily, beginning at different points after the induction of arthritis. Cross sections of the right distal femoral metaphysis were prepared, and intracortical defects were examined by computerized image analysis. The percentage of total bone area with defects (the ratio of void area to total bone area) was greatly increased in the arthritic group compared with that in the normal group (p < 0.001). In all groups treated with the bisphosphonate, there was a significantly lower percentage of total bone area with defects compared with that in the arthritic group (p < 0.001). Treatment was likewise effective in reducing the zonal (anterior and posterior) predilection for the formation of defects observed in arthritis. Although inflammatory arthritis has a substantial effect in producing intracortical defects in metaphyseal bone, a bisphosphonate, zoledronate, was considerably effective in preventing these changes from occurring.

Animals↗
PubMed1997

Stiffness of trabecular bone of the tibial plateau in patients with rheumatoid arthritis of the knee.

Stiffness of subchondral proximal tibial trabecular bone is a factor in the stability of prostheses implanted into that bone. The stiffness of trabecular bone in osteoarthritis (OA) has been documented. Trabecular bone in rheumatoid arthritis (RA) is osteopenic in numerous sites and morphologically abnormal in the proximal tibia. Reliable data on proximal tibial bone in RA are lacking, although 1 study failed to identify abnormalities. The purposes of this study were (1) to document the stiffness of the proximal tibial cancellous bone in patients with RA, (2) to determine the effect of angular deformity on bone stiffness in rheumatoid patients, and (3) to compare RA stiffness values with those in published reports for OA. Fifteen tibial plateau were obtained from patients with RA during surgery. Each plateau was horizontally seated in a mold and covered with cement. The plateau was divided into 6 regions, which were used to facilitate comparison between specimens and the existing literature. Indentation tests were conducted with a 4-mm-diameter cylindrical indentor controlled by an MTS machine. The indentor descended at a rate of 2 mm/min to a maximum depth of 1.0 mm; load and displacement data were digitally recorded. Stiffness was calculated from the slope of the linear region of the curve using best-fit linear regression. Where varus deformity was present, stiffness in the medial plateau was higher overall than for the other compartment; whereas in the case of valgus deformity, stiffness of the lateral side was significantly higher (P < .05 for each observation). In comparison to older normal specimens, both the medial compartment of the varus RA specimens (P < .01) and the posterolateral compartment of the valgus RA specimens (P < .01) had significantly lower stiffness. Comparison with OA specimens showed that in varus RA, the posteromedial region had significantly lower stiffness than in varus OA at the same site (P < .01). In valgus RA, the lateral region had significantly lower stiffness than in valgus OA at the same site (P < .01). The mean stiffness ratio of the valgus RA was significantly (P < .01) altered from normal, and for the varus RA, it was significantly (P < .01) different from normal posteriorly. The stiffness ratios for the varus RA were significantly (P < .01) different from those for varus OA; there was no difference between valgus RA and valgus OA. It is concluded that RA affected bone has significantly lower stiffness than normal and osteoarthritic bone. The loaded plateau is stiffer than the unloaded plateau in angular deformity, but is still less stiff than normal bone and osteoarthritic plateaus with corresponding deformities.

Arthritis, Rheumatoid↗
PubMed1996

Restoration of metacarpophalangeal extension of the thumb in inflammatory arthritis.

Nine patients (11 cases) with inflammatory arthritis who had an early boutonnière deformity of the thumb treated by rerouting of the extensor pollicis longus tendon were reviewed. Preoperatively, all patients complained of pain, disability in activities of daily living and extensor lag of the MP joint ranging from 10 to 60 degrees. At a mean follow-up of 38 months, nine thumbs had equal active and passive MP joint extension. Two thumbs had a moderate extensor lag. Functional strength assessment demonstrated no deleterious effect of the procedure in the operated compared to the non-operated thumb. Subjectively, all patients but one were satisfied. This procedure appeared to correct or to limit the progression of the deformity. A deficit of interphalangeal extension in five patients may require a modification of the procedure to tighten the extensor pollicis longus distal to the MP joint.

Adult↗
PubMed1995

Arthritis not immobilization causes bone loss in the carrageenan injection model of inflammatory arthritis.

One suggested cause of the high turnover osteopenia of experimental inflammatory arthritis is disuse of affected joints. To compare the influence of immobilization or disuse, or both, with that of inflammatory arthritis on bone turnover, rabbits were placed into four groups. In group 1, arthritis was induced in the right knee by seven intra-articular injections of 1% carrageenan, over 49 days; in group 2, a plaster cast was applied to immobilize the right hindlimb in flexion; in group 3, arthritis was induced and the hindlimb was immobilized; and in group 4, nothing was done (control). The fluorescent label calcein was administered in drinking water (0.05%) ad libitum to all groups on days 22-36. On day 49, specimens were prepared for analysis of bone volume and new bone volume at a near site (right femur) and at remote sites (contralateral femur and ipsilateral humerus). The data were analysed by multiple regression and Bonferroni tests. In group 1, new bone volume was three times higher than in group 2 or 4 (p < 0.05 for each comparison); this indicated increased bone remodeling in the right femur. This contrasted with group 2, in which neither index of bone remodeling was changed. The combination of immobilization with arthritis resulted in more intense osseous effects of inflammatory arthritis, with a one-quarter decrease in bone volume (group 3, 30.99 +/- 2.50; group 4, 42.07 +/- 2.38, p < 0.05), as well as a 4-fold increase in new bone volume (p < 0.001) compared with group 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1995

Bisphosphonate (pamidronate/APD) prevents arthritis-induced loss of fracture toughness in the rabbit femoral diaphysis.

Patients with rheumatoid and other inflammatory arthritis have an increased risk for fracture. This study was designed to determine the effect of experimental inflammatory arthritis on the material properties (fracture toughness and shear modulus) and structural properties (torque, angular deflection, and absorbed energy) of femoral diaphyseal bone tested in torsion to fracture, as well as the effect on these properties of APD (3-amino-1-hydroxypropylidene-1,1-bisphosphonate), a drug known to block osteoclast activity. Two dose levels were investigated. Experimental inflammatory arthritis was induced by intra-articular injection of carrageenan into the right tibiofemoral joint, given over 7 weeks, in three groups of animals. Simultaneously, daily subcutaneous injections of APD were given to three groups of rabbits. Five groups (12 animals each) were established: normal, arthritis, normal/high dose APD, arthritis/high dose APD, and arthritis/low dose APD. The diaphyses of each excised right femur were loaded to fracture in torsion at an angular deflection rate of 8 degrees/sec. In the arthritis group, the fracture toughness was 39% lower than in the normal group, and the structural properties all were reduced significantly. By contrast, the shear modulus was unaffected by arthritis. In this study, the higher dose level (0.3 mg/kg of body weight) of APD prevented loss of fracture toughness and maintained the structural properties in experimental inflammatory arthritis; the low dose was not effective.

Animals↗
PubMed1995

Kinematics of the distal radioulnar joint in rheumatoid arthritis: an in vivo study using centrode analysis.

The kinematics of the distal radioulnar joint were examined using the method of centrode analysis in vivo. A group of normal subjects was studied along with a group of rheumatoid arthritis patients who had distal radioulnar joint involvement. Serial computed tomographic scans were obtained through the distal radioulnar joint of nine subjects (10 wrists) in varying degrees of pronation and supination. For normal subjects, the movement that occurs in a stable distal radioulnar joint is not erratic and the center of rotation lies within a well-defined area. When subjects with rheumatoid arthritis were analyzed, it was determined that early in the disease process bone erosions may occur in the sigmoid notch of the distal radius. When the joint contour in this region is maintained, the kinematics are not markedly altered. Erosion involving the dorsal border of the sigmoid notch of the radius is associated with subluxation of the distal radioulnar joint. The ulna becomes dorsally positioned relative to the radius, and significant alteration in the kinematics of the distal radioulnar joint occurs.

Adult↗
PubMed1994

Heterotopic ossification after primary cemented and noncemented total hip arthroplasty in patients with osteoarthritis and rheumatoid arthritis.

OBJECTIVE: To compare the frequency and severity of heterotopic ossification (HO) in patients with osteoarthritis or rheumatoid arthritis who undergo cemented or noncemented total hip arthroplasty. DESIGN: A prospective case study. SETTING: A university referral centre. PATIENTS: One hundred and sixty one patients underwent 184 total hip arthroplasties. The 184 hips were categorized as follows: cemented total hip arthroplasty--60 osteoarthritis hips, 26 hips affected by rheumatoid arthritis; noncemented total hip arthroplasty--67 osteoarthritic hips, 31 hips affected by rheumatoid arthritis. INTERVENTIONS: Total hip arthroplasty. A standard approach was used to implant either a cemented or noncemented prosthesis. Radiographs were obtained of each hip preoperatively, immediately postoperatively and 6 weeks, 3 months, 6 months and 1 year postoperatively. MAIN OUTCOME MEASURES: Radiographs were graded in blind fashion for HO, according to the criteria of Brooker. Modified Harris hip scores were calculated at 1 and 2 years postoperatively. RESULTS: HO (incidence of Brooker grades 2, 3 and 4) was greater after cemented (22%) than noncemented (9%) total hip arthroplasty in osteoarthritic hips (p < 0.05), but there was no significant difference between the two types of prosthesis in hips affected by rheumatoid arthritis. When both types of prosthesis were considered together there was no significant difference in the incidence of HO between osteoarthritic hips (15%) and hips affected by rheumatoid arthritis (12%). With respect to Harris hip score, the presence of grade 4 HO was associated with a significantly (p < 0.05) lower score (50.6) than grade 3 (89.4) and grade 2 (91) HO. CONCLUSIONS: Cemented total hip arthroplasty increases the frequency of HO only in osteoarthritic hips. Compared with Brooker's grades 2 and 3 HO, grade 4 HO significantly lowers the Harris hip score after total hip arthroplasty.

Adult↗
PubMed1993

Intertrochanteric fractures of the femur in rheumatoid arthritis patients.

In a series of 33 intertrochanteric femoral fractures in patients suffering from classic rheumatoid arthritis (RA), the typical patient was about 70 years of age, osteopenic, and severely affected by longstanding polyarticular RA of joints other than the hip. Prefracture involvement of the hip joint (other than osteopenia) was apparent radiographically in only 9.1% of patients. There was a higher rate of avascular necrosis (9.7%) and nonunion (6.5%) than expected in the nonrheumatoid general population. There was also a high rate of secondary displacement. Of three patients with avascular necrosis, two had had corticosteroid treatment.

Aged↗
PubMed1992

Surgery of rheumatoid arthritis in peripheral joints.

The wide range of publications that are the basis of the following discussion highlight the difficulties of scientific assessment of surgical treatment in rheumatoid arthritis. Some factors that bedevil objective assessment include the variable clinical course of the disease, parallel pharmacologic and surgical treatments, the virtual impossibility of identifying appropriate control subjects and imprecision in endpoint measurement. Nevertheless, study design in rheumatoid arthritis surgery is becoming more sophisticated through the efforts of numerous individuals and groups such as the European Rheumatoid Arthritis Surgical Society.

Arthritis, Rheumatoid↗
PubMed1989

The 'occult' compartment syndrome.

Two cases of compartment syndromes after tibial fractures are presented in patients who had no sensation in the involved compartments. The absence of any clinical symptoms in these patients emphasizes the need for routine monitoring of intra-compartmental pressure in this select group of patients.

Adult↗
PubMed1987

Silicone synovitis.

Explore the source record for details and available documents.

Arthritis, Rheumatoid↗
PubMed1983

Successful surgical decompression of spinal extradural metastases of liposarcoma.

Two patients with metastatic liposarcoma to the spine developed neurologic deficits that were successfully reversed by laminectomy and partial tumor resections. Recurrences at later dates were treated similarly with comparable outcomes. Paraplegia was forestalled for approximately two years by each of the surgical interventions.

Aged↗