Fibrocartilage
Cartilago fibrosa
Also known as: fibrous cartilage, white fibrocartilage
A tough blend of dense regular connective tissue and cartilage — rows of chondrocytes between thick bundles of type I collagen — that resists compression and shear; it has no perichondrium.
Overview
Fibrocartilage contains both type I and type II collagen: thick, visible bundles of type I collagen alternate with rows or small groups of chondrocytes in lacunae surrounded by a little hyaline-like (type II, aggrecan-containing) matrix. Fibroblasts are also present. It has no perichondrium and typically blends into adjacent dense connective tissue or hyaline cartilage. This combination gives tensile strength and resistance to compression and shear — ideal for pads between bones and for attachment zones.
Its best-known site is the intervertebral disc: a ring of concentric fibrocartilaginous lamellae (anulus fibrosus), whose fibres run obliquely in alternating directions, encloses the gelatinous nucleus pulposus (a notochordal remnant in childhood, rich in type II collagen and proteoglycan). Fibrocartilage also forms the pubic symphysis, the menisci of the knee, the articular discs of the temporomandibular, sternoclavicular and distal radioulnar joints, the glenoid and acetabular labra, and many tendon and ligament insertions into bone (fibrocartilaginous entheses).
- Location
Intervertebral discs (anulus fibrosus); pubic symphysis; menisci of the knee; articular discs (TMJ, sternoclavicular, distal radioulnar); labra; entheses.
Anatomy
- Histology
Parallel pink (acidophilic) collagen bundles with chondrocytes in lacunae arranged in rows (often in pairs) between them; little basophilic matrix; no perichondrium.
Function
- Shock absorption and resistance to compression and shear.
- Joins bones in secondary cartilaginous joints (symphyses).
- Deepens and stabilises joints (labra, menisci).
Clinical significance
Herniated intervertebral disc
Degeneration and tears of the anulus fibrosus allow the nucleus pulposus to herniate, usually posterolaterally (where the posterior longitudinal ligament is weakest), compressing the nerve root — most often at L4–L5 or L5–S1 (sciatica) and C5–C6/C6–C7 in the neck. A posterolateral L4–L5 herniation typically compresses the L5 root.
Meniscal tears
Twisting injuries of the flexed, weight-bearing knee tear the menisci (medial more often, being attached to the medial collateral ligament). Only the vascular outer third ("red zone") heals well, influencing repair versus resection.
Test yourself
Which tissue forms the anulus fibrosus of the intervertebral disc and the pubic symphysis?
- Hyaline cartilage
- Elastic cartilage
- Fibrocartilage
- Dense irregular connective tissue
Answer: Fibrocartilage
Fibrocartilage combines rows of chondrocytes with thick bundles of type I collagen, resisting compression and shear. It has no perichondrium. Also found in menisci, articular discs and labra.
Compiled from standard anatomy and physiology references — see the Cells & Tissues sources. For education only; not medical advice.