Related Experiment Video
Updated: Jun 28, 2026

Integrated Bone Formation Through In Vivo Endochondral Ossification Using Mesenchymal Stem Cells
Published on: July 14, 2023
[Ochronosis or black cartilage disease]
R Philippot1, C Coste, E Lasseur
1Service de chirurgie orthopédique et traumatologique, hôpital Lyon-Sud, 69310 Pierre-Bénite, France. r_philippot@yahoo.fr
Ochronosis is a rare genetic disorder causing black deposits in tissues, leading to joint destruction. Early diagnosis and multidisciplinary care are crucial for managing this condition and preventing complications.
Area of Science:
- Genetics
- Biochemistry
- Rheumatology
Background:
- Ochronosis is a rare metabolic disorder with autosomal recessive inheritance.
- It stems from an enzyme deficiency, leading to homogentisic acid accumulation.
- The condition affects connective tissues, manifesting clinically over time.
Observation:
- Two cases of ochronosis are presented.
- Clinical presentation includes black deposits in connective tissues.
- Progressive symptoms involve joints, particularly larger ones, leading to destructive arthropathy.
Findings:
- Diagnosis is frequently delayed.
- Early detection is vital to prevent severe complications like infectious endocarditis.
- Current drug therapies show promise for symptom management.
Implications:
- Ochronosis requires tailored, multidisciplinary patient care.
- Integrated approaches involving social support and symptomatic treatment are essential.
- Ongoing research into drug therapies aims to improve patient outcomes and quality of life.
Related Concept Videos
Bone Formation by Endochondral Ossification
Growth of Cartilage and Bone Tissue
Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
Changes in the Appendicular Skeleton with Age
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
Compact Bone
Compact bone, also called cortical bone, is the denser, stronger of the two types of bone tissue. It is found under the periosteum and in the diaphyses of long bones, where it provides support and protection. The microscopic structural unit of compact bone is called an osteon, or haversian system. Each osteon is composed of concentric rings of calcified...
Osteoclasts in Bone Remodeling

