symphyses

Symphyses are a class of fibrocartilaginous joints characterized by a thin, plate‑like disc of fibrocartilage that unites two adjacent bones, allowing limited movement while providing strong resistance to shear forces. The fibrocartilaginous disc is surrounded by a capsule of dense connective tissue, and the joint surfaces are typically covered by a thin layer of hyaline cartilage. This structure combines the stability of a sutured connection with a modest degree of mobility, which is essential in regions subjected to repetitive stress.

The most commonly referenced symphysis is the pubic symphysis, located at the midline of the pelvis where the left and right superior pubic ravelments meet. It accommodates slight rocking movements during gait and expands during pregnancy under the influence of relaxin, facilitating parturition. Another example is the intervertebral symphysis, formed by the intervertebral discs that separate vertebral bodies and act as shock absorbers for the spinal column. The mandibular symphysis, present in early development, fuses the two halves of the mandible into a single bone; remnants of this joint persist as a line of weakness in certain pathological conditions.

Clinically, disorders of symphyses may present as pain, instability, or degenerative changes. Pubic symphysis dysfunction can cause dyspareunia or lower‑abdominal discomfort, while disc degeneration at intervertebral symphyses contributes to low back pain. Imaging modalities such as MRI and CT are employed to assess disc integrity, inflammation, and associated soft‑tissue alterations. Treatment strategies range from conservative physiotherapy and anti‑inflammatory medication to surgical intervention in severe or refractory cases.