Flexor,Extensor And Peroneal Retinaculum|Ashwini Sir|Anatomy ✅✅

Summary

This video provides a detailed explanation of the retinacula in the lower limb, focusing on the flexor, extensor, and peroneal retinacula. It covers the anatomical structures, their attachment points, and the arrangement of tendons, arteries, and nerves passing through these retinacula. The use of mnemonics like 'Tom Dick and Harry' and 'Tall Husbands Are Not Dear People' helps simplify the complex sequence of structures. The video also discusses the importance of these retinacula in preventing 'bow-stringing' and ensuring efficient muscle function, emphasizing the role of retinacula in maintaining tendon position across the foot and ankle.

Takeaways

• 😀 The flexor retinaculum is located on the medial side of the foot, extending from the medial malleolus to the medial surface of the calcaneus.
• 😀 The arrangement of structures beneath the flexor retinaculum is remembered using the mnemonic 'Tom, Dick, And Harry', representing Tibialis posterior, Flexor digitorum longus, posterior tibial artery, tibial nerve, and Flexor hallucis longus.
• 😀 The extensor retinaculum has two bands: the superior band extends from the anterior surface of the fibula to the anterior surface of the tibia, while the inferior band is Y-shaped and attaches to the calcaneus.
• 😀 Structures passing through the extensor retinaculum include Tibialis anterior, Extensor hallucis longus, Dorsalis pedis artery, Deep peroneal nerve, Extensor digitorum longus, and Peroneus tertius.
• 😀 The peroneal retinaculum on the lateral side of the foot holds the tendons of peroneus longus and peroneus brevis in place, with the upper band attaching to the lateral malleolus.
• 😀 The function of the retinacula is to prevent bowstringing of the tendons, which would reduce their efficiency in exerting force at joints.
• 😀 The bowstringing phenomenon occurs when tendons pop out of place without retinacula, losing their ability to function effectively at the joint.
• 😀 Retinacula in the wrist and foot regions maintain the position of tendons, ensuring they work effectively by keeping them close to the joints they act upon.
• 😀 The superior band of the extensor retinaculum attaches to the anterior borders of both the fibula and tibia, while the inferior band splits into two parts, attaching to the medial malleolus and the plantar aponeurosis.
• 😀 The arrangement of tendons and structures beneath the retinacula is essential for the proper function of the muscles in the lower limb, as they ensure tendons are aligned to exert force in the desired direction.

Q & A

What is the function of the flexor retinaculum in the foot?

The flexor retinaculum in the foot serves to hold tendons and blood vessels in place as they pass from the posterior leg to the foot, preventing them from bowstringing during movement. It attaches from the medial malleolus to the medial surface of the calcaneus.

How can the structures deep to the flexor retinaculum be remembered?

The arrangement of structures deep to the flexor retinaculum can be remembered using the mnemonic 'Tom Dick and Harry'. This corresponds to Tibialis posterior (T), Flexor digitorum longus (D), Posterior tibial artery and tibial nerve (A and N), and Flexor hallucis longus (H).

Where is the flexor retinaculum located in the foot?

The flexor retinaculum is located on the medial side of the ankle, extending from the medial malleolus to the medial surface of the calcaneus. It lies posteriorly to the tibia.

What structures pass beneath the flexor retinaculum from medial to lateral?

From medial to lateral, the structures passing beneath the flexor retinaculum are: Tibialis posterior tendon, Flexor digitorum longus tendon, Posterior tibial artery, Tibial nerve, and Flexor hallucis longus tendon.

What is the significance of the term 'bowstringing' in the context of retinacula?

Bowstringing refers to the condition where tendons, without the support of a retinaculum, move away from the joint during movement, resembling the string of a bow. The retinacula prevent this by holding the tendons close to the joints, ensuring effective muscle function.

What is the difference between the flexor and extensor retinaculum in terms of location and structure?

The flexor retinaculum is located on the medial side of the ankle, while the extensor retinaculum is located on the dorsum of the foot. The extensor retinaculum has two bands: a superior band attaching from the anterior border of the fibula to the anterior border of the tibia, and an inferior Y-shaped band that attaches to the calcaneus.

How are the bands of the extensor retinaculum arranged?

The extensor retinaculum has two bands: the superior band extends from the anterior border of the fibula to the anterior border of the tibia, while the inferior Y-shaped band originates from the nonarticular part of the calcaneus and splits into two branches. The upper branch attaches to the medial malleolus, and the lower branch attaches to the plantar aponeurosis.

What mnemonic can be used to remember the structures passing through the extensor retinaculum?

The mnemonic 'Tall husbands are not dear people' (or 'The Himalayas are not dry places') can help remember the structures passing through the extensor retinaculum. These include: Tibialis anterior (T), Extensor hallucis longus (H), Dorsalis pedis artery (A), Deep peroneal nerve (N), Extensor digitorum longus (D), and Peroneus tertius (P).

What are the two types of retinacula found on the lateral side of the foot, and what are their functions?

The two types of retinacula found on the lateral side of the foot are the superior and inferior peroneal retinacula. These retinacula secure the tendons of the peroneus longus and peroneus brevis muscles to prevent dislocation during movement.

Why is the peroneal retinaculum important for the peroneal tendons?

The peroneal retinaculum is important because it prevents the peroneal tendons (peroneus longus and peroneus brevis) from slipping out of place. The upper band attaches to the lateral malleolus, and both bands are anchored to the lateral surface of the calcaneus.