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Subchondral Bone (subchondral + bone)
Selected AbstractsHabitual use of the primate forelimb is reflected in the material properties of subchondral bone in the distal radiusJOURNAL OF ANATOMY, Issue 6 2006Kristian J. Carlson Abstract Bone mineral density is directly proportional to compressive strength, which affords an opportunity to estimate in vivo joint load history from the subchondral cortical plate of articular surfaces in isolated skeletal elements. Subchondral bone experiencing greater compressive loads should be of relatively greater density than subchondral bone experiencing less compressive loading. Distribution of the densest areas, either concentrated or diffuse, also may be influenced by the extent of habitual compressive loading. We evaluated subchondral bone in the distal radius of several primates whose locomotion could be characterized in one of three general ways (quadrupedal, suspensory or bipedal), each exemplifying a different manner of habitual forelimb loading (i.e. compression, tension or non-weight-bearing, respectively). We employed computed tomography osteoabsorptiometry (CT-OAM) to acquire optical densities from which false-colour maps were constructed. The false-colour maps were used to evaluate patterns in subchondral density (i.e. apparent density). Suspensory apes and bipedal humans had both smaller percentage areas and less well-defined concentrations of regions of high apparent density relative to quadrupedal primates. Quadrupedal primates exhibited a positive allometric effect of articular surface size on high-density area, whereas suspensory primates exhibited an isometric effect and bipedal humans exhibited no significant relationship between the two. A significant difference between groups characterized by predominantly compressive forelimb loading regimes vs. tensile or non-weight-bearing regimes indicates that subchondral apparent density in the distal radial articular surface distinguishes modes of habitually supporting of body mass. [source] Subchondral bone and cartilage damage: A prospective study in older adultsARTHRITIS & RHEUMATISM, Issue 7 2010Dawn Doré Objective There is limited longitudinal evidence relating subchondral bone changes to cartilage damage and loss. The aim of this study was to describe the association between baseline tibial bone area and tibial subchondral bone mineral density (BMD) with tibial cartilage defect development and cartilage volume loss. Methods A total of 341 subjects (mean age 63 years, range 52,79 years) underwent measurement at baseline and ,2.7 years later. Tibial knee cartilage volume, cartilage defects (graded on a scale of 0,4), and bone area were determined using T1-weighted fat suppression magnetic resonance imaging. Tibial subchondral BMD was determined using dual x-ray absorptiometry. Results In multivariable analysis, baseline bone area positively predicted cartilage defect development at the medial and lateral tibial sites (odds ratio [OR] 1.6 per 1 SD increase, 95% confidence interval [95% CI] 1.0, 2.6, and OR 2.4 per 1 SD increase, 95% CI 1.4, 4.0, respectively) and cartilage volume loss at the medial tibial site (, = ,34.9 per 1 SD increase, 95% CI ,49.8, ,20.1). In contrast, baseline subchondral BMD positively predicted cartilage defect development at the medial tibial site only (OR 1.6 per 1 SD increase, 95% CI 1.2, 2.1) and was not associated with cartilage loss. Conclusion The results of this study demonstrated that bone area predicted medial and lateral cartilage defect development and medial cartilage volume loss, while subchondral BMD predicted medial defect development but not cartilage loss. These associations were independent of each other, indicating there are multiple mechanisms by which subchondral bone changes may lead to cartilage damage. [source] Habitual use of the primate forelimb is reflected in the material properties of subchondral bone in the distal radiusJOURNAL OF ANATOMY, Issue 6 2006Kristian J. Carlson Abstract Bone mineral density is directly proportional to compressive strength, which affords an opportunity to estimate in vivo joint load history from the subchondral cortical plate of articular surfaces in isolated skeletal elements. Subchondral bone experiencing greater compressive loads should be of relatively greater density than subchondral bone experiencing less compressive loading. Distribution of the densest areas, either concentrated or diffuse, also may be influenced by the extent of habitual compressive loading. We evaluated subchondral bone in the distal radius of several primates whose locomotion could be characterized in one of three general ways (quadrupedal, suspensory or bipedal), each exemplifying a different manner of habitual forelimb loading (i.e. compression, tension or non-weight-bearing, respectively). We employed computed tomography osteoabsorptiometry (CT-OAM) to acquire optical densities from which false-colour maps were constructed. The false-colour maps were used to evaluate patterns in subchondral density (i.e. apparent density). Suspensory apes and bipedal humans had both smaller percentage areas and less well-defined concentrations of regions of high apparent density relative to quadrupedal primates. Quadrupedal primates exhibited a positive allometric effect of articular surface size on high-density area, whereas suspensory primates exhibited an isometric effect and bipedal humans exhibited no significant relationship between the two. A significant difference between groups characterized by predominantly compressive forelimb loading regimes vs. tensile or non-weight-bearing regimes indicates that subchondral apparent density in the distal radial articular surface distinguishes modes of habitually supporting of body mass. [source] Micro-computed tomography evaluation of vertebral end-plate trabecular bone changes in a porcine asymmetric vertebral tetherJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2010Jean-Michel Laffosse Abstract We conducted a micro-CT analysis of subchondral bone of the vertebral end-plates after application of compressive stress. Thoracic and lumbar vertebral units were instrumented by carrying out left asymmetric tether in eleven 4-week-old pigs. After 3 months of growth, instrumented units and control units were harvested. Micro-CT study of subchondral bone was performed on one central and two lateral specimens (fixated side and non-fixated side). In control units, bone volume fraction (BV/TV), number of trabeculae (Tb.N), trabecular thickness (Tb.Th), and degree of anisotropy (DA) were significantly higher, whereas intertrabecular space (Tb.Sp) was significantly lower in center than in periphery. No significant difference between the fixated and non-fixated sides was found. In instrumented units, BV/TV, Tb.N, Tb.Th, and DA were significantly higher in center than in periphery. BV/TV, Tb.N, and Conn.D were significantly higher in fixated than in non-fixated side, while Tb.Sp was significantly lower. We noted BV/TV, Tb.N, and Tb.Th significantly lower, and Tb.Sp significantly higher, in the instrumented levels. This study showed, in instrumented units, two opposing processes generating a reorganization of the trabecular network. First, an osteolytic process (decrease in BV/TV, Tb.N, Tb.Th) by stress-shielding, greater in center and on non-fixated side. Second, an osteogenic process (higher BV/TV, Tb.N, Conn.D, and lower Tb.Sp) due to the compressive loading induced by growth on the fixated side. This study demonstrates the densification of the trabecular bone tissue of the vertebral end-plates after compressive loading, and illustrates the potential risks of excessively rigid spinal instrumentation which may induce premature osteopenia. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:232,240, 2010 [source] Repair of porcine articular cartilage defect with a biphasic osteochondral composite,JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 10 2007Ching-Chuan Jiang Abstract Autologous chondrocyte implantation (ACI) has been recently used to treat cartilage defects. Partly because of the success of mosaicplasty, a procedure that involves the implantation of native osteochondral plugs, it is of potential significance to consider the application of ACI in the form of biphasic osteochondral composites. To test the clinical applicability of such composite construct, we repaired osteochondral defect with ACI at low cell-seeding density on a biphasic scaffold, and combined graft harvest and implantation in a single surgery. We fabricated a biphasic cylindrical porous plug of DL-poly-lactide-co-glycolide, with its lower body impregnated with ,-tricalcium phosphate as the osseous phase. Osteochondral defects were surgically created at the weight-bearing surface of femoral condyles of Lee-Sung mini-pigs. Autologous chondrocytes isolated from the cartilage were seeded into the upper, chondral phase of the plug, which was inserted by press-fitting to fill the defect. Defects treated with cell-free plugs served as control. Outcome of repair was examined 6 months after surgery. In the osseous phase, the biomaterial retained in the center and cancellous bone formed in the periphery, integrating well with native subchondral bone with extensive remodeling, as depicted on X-ray roentgenography by higher radiolucency. In the chondral phase, collagen type II immunohistochemistry and Safranin O histological staining showed hyaline cartilage regeneration in the experimental group, whereas only fibrous tissue formed in the control group. On the International Cartilage Repair Society Scale, the experimental group had higher mean scores in surface, matrix, cell distribution, and cell viability than control, but was comparable with the control group in subchondral bone and mineralization. Tensile stress,relaxation behavior determined by uni-axial indentation test revealed similar creep property between the surface of the experimental specimen and native cartilage, but not the control specimen. Implanted autologous chondrocytes could survive and could yield hyaline-like cartilage in vivo in the biphasic biomaterial construct. Pre-seeding of osteogenic cells did not appear to be necessary to regenerate subchondral bone. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1277,1290, 2007 [source] Proteoglycan-induced changes in T1, -relaxation of articular cartilage at 4TMAGNETIC RESONANCE IN MEDICINE, Issue 3 2001Sarma V.S. Akella Abstract Proteoglycan (PG) depletion-induced changes in T1, (spin-lattice relaxation in rotating frame) relaxation and dispersion in articular cartilage were studied at 4T. Using a spin-lock cluster pre-encoded fast spin echo sequence, T1, maps of healthy bovine specimens and specimens that were subjected to PG depletion were computed at varying spin-lock frequencies. Sequential PG depletion was induced by trypsinization of cartilage for varying amounts of time. Results demonstrated that over 50% depletion of PG from bovine articular cartilage resulted in average T1, increases from 110,170 ms. Regression analysis of the data showed a strong correlation (R2 = 0.987) between changes in PG and T1,. T1, values were highest at the superficial zone and decreased gradually in the middle zone and again showed an increasing trend in the region near the subchondral bone. The potentials of this method in detecting early degenerative changes of cartilage are discussed. Also, T1, -dispersion changes as a function of PG depletion are described. Magn Reson Med 46:419,423, 2001. © 2001 Wiley-Liss, Inc. [source] Apparent density of the primate calcaneo-cuboid joint and its association with locomotor mode, foot posture, and the "midtarsal break"AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2010Matthew G. Nowak Abstract Primates use a range of locomotor modes during which they incorporate various foot postures. Humans are unique compared with other primates in that humans lack a mobile fore- and midfoot. Rigidity in the human foot is often attributed to increased propulsive and stability requirements during bipedalism. Conversely, fore- and midfoot mobility in nonhuman primates facilitates locomotion in arboreal settings. Here, we evaluated apparent density (AD) in the subchondral bone of human, ape, and monkey calcanei exhibiting different types of foot loading. We used computed tomography osteoabsorptiometry and maximum intensity projection (MIP) maps to visualize AD in subchondral bone at the cuboid articular surface of calcanei. MIPs represent 3D volumes (of subchondral bone) condensed into 2D images by extracting AD maxima from columns of voxels comprising the volumes. False-color maps are assigned to MIPs by binning pixels in the 2D images according to brightness values. We compared quantities and distributions of AD pixels in the highest bin to test predictions relating AD patterns to habitual locomotor modes and foot posture categories of humans and several nonhuman primates. Nonhuman primates exhibit dorsally positioned high AD concentrations, where maximum compressive loading between the calcaneus and cuboid likely occurs during "midtarsal break" of support. Humans exhibit less widespread areas of high AD, which could reflect reduced fore- and midfoot mobility. Analysis of the internal morphology of the tarsus, such as subchondral bone AD, potentially offers new insights for evaluating primate foot function during locomotion. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source] Alteration of sensory neurons and spinal response to an experimental osteoarthritis pain modelARTHRITIS & RHEUMATISM, Issue 10 2010Hee-Jeong Im Objective To verify the biologic links between progressive cellular and structural alterations within knee joint components and development of symptomatic chronic pain that are characteristic of osteoarthritis (OA), and to investigate the molecular basis of alterations in nociceptive pathways caused by OA-induced pain. Methods An animal model of knee joint OA pain was generated by intraarticular injection of mono-iodoacetate (MIA) in Sprague-Dawley rats, and symptomatic pain behavior tests were performed. Relationships between development of OA with accompanying pain responses and gradual alterations in cellular and structural knee joint components (i.e., cartilage, synovium, meniscus, subchondral bone) were examined by histologic and immunohistologic analysis, microscopic examination, and microfocal computed tomography. Progressive changes in the dynamic interrelationships between peripheral knee joint tissue and central components of nociceptive pathways caused by OA-induced pain were examined by investigating cytokine production and expression in sensory neurons of the dorsal root ganglion and spinal cord. Results We observed that structural changes in components of the peripheral knee joint correlate with alterations in the central compartments (dorsal root ganglia and the spinal cord) and symptomatic pain assessed by behavioral hyperalgesia. Our comparative gene expression studies revealed that the pain pathways in MIA-induced knee OA may overlap, at least in part, with neuropathic pain mechanisms. Similar results were also observed upon destabilization of the knee joint in the anterior cruciate ligament transection and destabilization of the medial meniscus models of OA. Conclusion Our results indicate that MIA-induced joint degeneration in rats generates an animal model that is suitable for mechanistic and pharmacologic studies on nociceptive pain pathways caused by OA, and provide key in vivo evidence that OA pain is caused by central sensitization through communication between peripheral OA nociceptors and the central sensory system. Furthermore, our data suggest a mechanistic overlap between OA-induced pain and neuropathic pain. [source] Denuded subchondral bone and knee pain in persons with knee osteoarthritisARTHRITIS & RHEUMATISM, Issue 12 2009Kirsten Moisio Objective It is unclear how articular cartilage loss contributes to pain in patients with knee osteoarthritis (OA). Full-thickness cartilage defects expose the subchondral bone plate. The relationship between denuded bone and pain has not been examined. The aim of this study was to investigate whether the percent of denuded bone is associated with moderate-to-severe knee pain or frequent knee pain and longitudinally with frequent knee pain 2 years after the baseline evaluation. Methods We studied 182 persons with knee OA (305 knees). Applying specialized magnetic resonance imaging techniques, manual segmentation was used to compute cartilage-covered and denuded bone areas for each surface. Moderate-to-severe knee pain was defined as a score of ,40 mm on a knee-specific 100-mm visual analog scale, and frequent knee pain was defined as pain on most days during the past month. Logistic regression and generalized estimating equations were used in analyses, adjusting for age, sex, body mass index, and bone marrow lesions. Results Cross-sectional analyses revealed that moderate-to-severe knee pain was associated with percent denuded bone in the medial compartment (adjusted odds ratio [OR] 3.90, 95% confidence interval [95% CI] 1.33,11.47), in the medial and patellar surfaces together, and in the lateral and patellar surfaces. Frequent knee pain was associated with percent denuded bone in the patellar surface (adjusted OR 3.11, 95% CI 1.24,7.81), in the medial and patellar surfaces, and in the lateral and patellar surfaces. Longitudinal analyses (in 168 knees without frequent knee pain at baseline) revealed that percent denuded bone in the medial and patellar surfaces was associated with frequent incident knee pain (adjusted OR 4.19, 95% CI 1.56,11.22). Conclusion These results support a relationship between subchondral bone plate exposure and prevalent and incident knee pain in patients with knee OA. [source] Kinetics of bone protection by recombinant osteoprotegerin therapy in Lewis rats with adjuvant arthritisARTHRITIS & RHEUMATISM, Issue 7 2002Giuseppe Campagnuolo Objective To assess the effect of different dosages and treatment schedules of osteoprotegerin (OPG) on joint preservation in an experimental model of adjuvant-induced arthritis (AIA). Methods Male Lewis rats with AIA (6,8 per group) were treated with a subcutaneous bolus of recombinant human OPG according to one of the following schedules: daily OPG (an efficacious regimen) starting at disease onset (days 9,15), early intervention (days 9,11), delayed intervention (days 13,15), and extended therapy (days 9,22). Inflammation (hind paw swelling) was quantified throughout the clinical course; osteoporosis (bone mineral density [BMD], by quantitative dual x-ray absorptiometry) and morphologic appraisals of inflammation, bone damage, intralesional osteoclasts (by semiquantitative histopathologic scoring), and integrity of the articular cartilage matrix (by retention of toluidine blue stain) were determined in histology sections of arthritic hind paws. Results OPG provided dose- and schedule-dependent preservation of BMD and periarticular bone while essentially eliminating intralesional osteoclasts. Dosages ,2.5 mg/kg/day preserved or enhanced BMD and prevented essentially all erosions. A dosage of 4 mg/kg/day protected joint integrity to a comparable degree when given for 7 (days 9,15) or 14 (days 9,22) consecutive days. At this dosage, early intervention (days 9,11) was twice as effective as delayed intervention (days 13,15) at preventing joint dissolution. Erosions and osteoclast scores were greatly decreased for 26 days (measured from the first treatment) after 7 or 14 daily doses of OPG (4 mg/kg/day). OPG treatment also prevented loss of cartilage matrix proteoglycans, an indirect consequence of protecting the subchondral bone. No OPG dosage or regimen alleviated weight loss, inflammation, or periosteal osteophyte production. Conclusion These data indicate that OPG preserves articular bone and (indirectly) articular cartilage in arthritic joints in a dose- and schedule-dependent manner, halts bone erosion when given at any point during the course of arthritis, produces sustained antierosive activity after a short course, and is most effective when initiated early in the disease. [source] | |||||||||||||