Early changes in morphology, bone mineral density and matrix composition of vertebrae lead to disc degeneration in aged collagen IX -/- mice.

Collagen IX (Col IX) is an important component of the cartilage extracellularmatrix and has been associated with degenerative cartilage disorders and chondrodysplasias in humans. Further, polymorphisms in Col IX are known risk factors for the development of early intervertebral disc (IVD) degeneration. To understand the role of Col IX in the pathogenesis of IVD disorders, the spine of newborn and older Col IX deficient mice was systematically analyzed and compared to C57BL/6N controls.

Moderate cyclic tensile strain alters the assembly of cartilage extracellular matrix proteins in vitro.

Mechanical loading influences the structural and mechanical properties of articular cartilage. The cartilage matrix protein collagen II essentially determines the tensile properties of the tissue and is adapted in response to loading. The collagen II network is stabilized by the collagen II-binding cartilage oligomeric matrix protein (COMP), collagen IX, and matrilin-3.

Stabilization effectiveness and functionality of different thumb orthoses in female patients with first carpometacarpal joint osteoarthritis.

Background: Thumb orthoses have to reconcile and satisfy competing goals: stability and mobility. The purpose of the study was to characterize the stabilization effectiveness and functionality of different thumb carpometacarpal osteoarthritis orthoses.

Methods: Eighteen female carpometacarpal osteoarthritis subjects were included.

Effect of carpometacarpal joint osteoarthritis, sex, and handedness on thumb in vivo kinematics.

Purpose: To investigate the influence of trapeziometacarpal (TMC) osteoarthritis (OA) on the 3-dimensional motion capability of the TMC and thumb metacarpophalangeal (MCP) joints. In order to examine other factors affecting the thumb's motion kinematics, we further aimed to address the influence of sex and handedness on the motion capability of normal TMC and MCP joints.

Methods: We included 18 healthy subjects (9 women, 9 men; 8 dominant hands, 10 nondominant hands) and 18 women with stage II/III TMC OA.

Topographical variations in articular cartilage and subchondral bone of the normal rat knee are age-related.

In osteoarthritis animal models the rat knee is one of the most frequently investigated joint. However, it is unknown whether topographical variations in articular cartilage and subchondral bone of the normal rat knee exist and how they are linked or influenced by growth and maturation. Detailed knowledge is needed in order to allow interpretation and facilitate comparability of published osteoarthritis studies.

Effect of whole-body vibration and insulin-like growth factor-I on muscle paralysis-induced bone degeneration after botulinum toxin injection in mice.

Botulinum toxin A (BTX)-induced muscle paralysis results in pronounced bone degradation with substantial bone loss. We hypothesized that whole-body vibration (WBV) and insulin-like growth factor-I (IGF-I) treatment can counteract paralysis-induced bone degradation following BTX injections by activation of the protein kinase B (Akt) signaling pathway. Female C57BL/6 mice (n = 60, 16 weeks) were assigned into six groups (n = 10 each): SHAM, BTX, BTX+WBV, BTX+IGF-I, BTX+WBV+IGF-I, and a baseline group, which was killed at the beginning of the study.

Doxycycline-induced expression of transgenic human tumor necrosis factor α in adult mice results in psoriasis-like arthritis.

Objective: To generate doxycycline-inducible human tumor necrosis factor α (TNFα)-transgenic mice to overcome a major disadvantage of existing transgenic mice with constitutive expression of TNFα, which is the limitation in crossing them with various knockout or transgenic mice.

Methods: A transgenic mouse line that expresses the human TNFα cytokine exclusively after doxycycline administration was generated and analyzed for the onset of diseases.

Results: Doxycycline-inducible human TNFα-transgenic mice developed an inflammatory arthritis- and psoriasis-like phenotype, with fore and hind paws being prominently affected.

Growth-related structural, biochemical, and mechanical properties of the functional bone-cartilage unit.

Articular cartilage and subchondral bone act together, forming a unit as a weight-bearing loading-transmitting surface. A close interaction between both structures has been implicated during joint cartilage degeneration, but their coupling during normal growth and development is insufficiently understood. The purpose of the present study was to examine growth-related changes of cartilage mechanical properties and to relate these changes to alterations in cartilage biochemical composition and subchondral bone structure.

The effect of level and downhill running on cortical and trabecular bone in growing rats.

Mechanical loading is essential for bone development and prevention of age-related bone diseases. Muscular contractions during physical activity and the generated strain magnitude are primary determinants for the osteogenic response. However, the adaptation capacity of bones, especially due to different muscle contraction types, is largely unknown.