sinfisis

Sinfisis, known in English as a symphysis, is a type of joint in which two bones are joined by a pad of fibrocartilage, forming a secondary cartilaginous joint (amphiarthrosis). The articulating surfaces are sometimes covered by hyaline cartilage, and the fibrocartilaginous disc provides cushioning and limited mobility between the bones.

Structure and function: A symphysis consists of opposing articular surfaces separated by a fibrocartilaginous disc or pad. The joint is reinforced by ligaments and may have a thin surrounding capsule. Movement at a symphysis is limited, but the joint allows some flexibility to absorb impact and accommodate small shifts in alignment.

Examples: The pubic symphysis unites the left and right pubic bones at the front of the pelvis. The intervertebral joints between adjacent vertebral bodies are also classified as symphyses, where the intervertebral discs act as the cartilaginous connectors. The mandibular symphysis is another example, where the two halves of the mandible fuse at the midline during development.

Development and clinical relevance: Symphyses develop from cartilaginous templates in early life and become fibrocartilaginous joints as they mature. They are generally stable but can become sources of pain if damaged or degenerative changes occur. The pubic symphysis can become more mobile during pregnancy due to hormonal effects, occasionally leading to pelvic pain or dysfunction.

Terminology: Sinfisis is the term used in some languages (such as Spanish and Portuguese) for this joint type; the corresponding English term is symphysis.