Retinaculum

Retinaculum

A retinaculum (plural: retinacula) is a band of thickened deep fascia around tendons that holds them in place. Its function is to stabilize a tendon and prevent it from bowing outwards when a joint is moved. Retinacula are found in various parts of the body, including the wrist, ankle, and knee.

Types of Retinacula

Wrist

• Flexor retinaculum of the hand: This structure is also known as the transverse carpal ligament. It forms the roof of the carpal tunnel and holds the flexor tendons of the hand in place.
• Extensor retinaculum of the hand: This retinaculum is located on the dorsal side of the wrist and holds the extensor tendons in place.

Ankle

• Flexor retinaculum of the foot: This retinaculum is located on the medial side of the ankle and holds the tendons of the deep flexor muscles in place.
• Extensor retinaculum of the foot: This structure is found on the dorsal side of the ankle and holds the extensor tendons in place.
• Peroneal retinaculum: This retinaculum is located on the lateral side of the ankle and holds the tendons of the peroneal muscles in place.

Knee

• Patellar retinaculum: This structure is part of the knee joint and helps to stabilize the patella (kneecap).

Function

The primary function of retinacula is to stabilize tendons and prevent them from bowing out during joint movement. This stabilization is crucial for the efficient transmission of muscle force to the bones, allowing for smooth and coordinated movements.

Clinical Significance

Damage or injury to a retinaculum can lead to instability of the associated tendons, resulting in pain and impaired movement. Conditions such as carpal tunnel syndrome and De Quervain's tenosynovitis are associated with issues in the retinacula of the wrist.

Related Pages

• Fascia
• Tendon
• Carpal tunnel
• Patella
• Ankle