Wrist Retinacula Anatomy PDF

anatomy of upper limb Wrist retinacula By Dr. Hassan Mohammed Rizk (Ph.D.) Associate Professor of Human Anatomy and Embryology  Case Study UPPER LIMB Ulna Radius...

anatomy of upper limb Wrist retinacula By Dr. Hassan Mohammed Rizk (Ph.D.) Associate Professor of Human Anatomy and Embryology  Case Study UPPER LIMB Ulna Radius Tr L S Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 2  Objectives: by the end of this lecture the student must understand the following knowledge: UPPER LIMB  Enumerate the carpal bones.  Identify and demonstrate the: 1)Flexor retinaculum. 2)Extensor retinaculum.  Identify and demonstrate the contents, compartments and relations of: 1)Carpal tunnel. 2)Extensor retinaculum (six tunnels). Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 3  Objective # ( 1 ) Bones of hand UPPER LIMB There are three groups of bones in the hand: 1) Eight carpal bones are the bones of the wrist. 2) Five metacarpals (I to V) are the bones of the metacarpus. 3) Fourteen phalanges: phalanges are the bones of the digits—the thumb has only two; the rest of the digits have three Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 4  Carpus (Carpal Bones)  The small carpal bones of the wrist are arranged in two rows, a proximal and a distal row, each consisting of four bones. UPPER LIMB  Proximal row: From lateral to medial 1) Scaphoid: boat-shaped bone). 2) Lunate, (crescent-shaped bone). 3) Triquetrum: (three-sided bone). 4) Pisiform: (pea-shaped bone).  Distal row: From lateral to medial 1) Trapezium: (irregular four-sided bone) 2) Trapezoid: (four-sided) 3) Capitate: (head (largest)). 4) Hamate: (hook). Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 5 UPPER LIMB Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 6  Carpal Bony Arche UPPER LIMB  The carpal bones form an arch, whose base is directed anteriorly.  The lateral side of carpal arch: is formed by a) Scaphoid. b) Trapezium.  The medial side of carpal arch: is formed by: a) Pisiform. b) Hamate.  The flexor retinaculum attaches to, and spans the distance between, the medial and lateral sides of the base to form the anterior wall of the so-called carpal tunnel.  The sides and roof of the carpal tunnel are formed by the arch of the carpal bones. Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 7 UPPER LIMB Muscles of the Anterior Compartment of Forearm Superficial layer Intermediate layer Deep layer Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 8 UPPER LIMB Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 9  Objective 2: Flexor Retinaculum  Definition: Is a thickening of deep fascia that holds the long flexor UPPER LIMB tendons in position at the wrist.  Site: Stretches across the front of the wrist.  Function: Converts the concave anterior surface of the carpal bones into an osteo-fascial tunnel, carpal tunnel, for the passage of the median nerve and the flexor tendons of the thumb and fingers.  The attachment to the trapezium consists of superficial and deep parts and forms a synovial lined tunnel for passage of the tendon of the flexor carpi radialis. Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 10 UPPER LIMB M L Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 12  Objective # ( 2 ) Carpal Tunnel  Boundaries of carpal tunnel: UPPER LIMB 1) Lateral wall: is formed by a) Scaphoid. Distally: hand b) Trapezium. 2) Medial wall: is formed by: a) Pisiform. b) Hamate. Anterior wall (Base) 3) Anterior wall (Base): flexor retinaculum. 4) Posterior wall (Roof): arch of the carpal bones. 5) Proximally: Continues with forearm. Posterior wall (Roof) 6) Distally: Continues with hand Proximally: forearm. Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 13  Objective # ( 2 ) Carpal Tunnel  Contents of carpal tunnel (structures deep to flexor retinaculum): UPPER LIMB 1) Four tendons of the flexor digitorum superficialis (FDS) Lie most anterior and medial. Tendons of middle and ring fingers lie anterior to tendons of index and little fingers. 2) Four tendons of the flexor digitorum profundus: posterior to (FDS) 3) Tendon of the flexor pollicis longus: Lies posterior and lateral. 4) Median nerve: lies anterior and lateral. 5) Synovial sheaths: which surround tendons. All the tendons of the flexor digitorum profundus and flexor digitorum superficialis are surrounded by a single synovial sheath. A separate sheath surrounds the tendon of the flexor pollicis longus. The tendon of the flexor carpi radialis is surrounded by a synovial sheath and passes through a tubular compartment formed by the attachment of the lateral aspect of the flexor retinaculum. Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 14 UPPER LIMB M L Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 15  Objective # ( 2 ) Carpal Tunnel UPPER LIMB  Structures outside carpal tunnel (structures superficial to flexor retinaculum): from medial to lateral 1) Ulnar nerve. 2) Ulnar artery. 3) Palmar cutaneous nerve of ulnar nerve. 4) Tendon of the palmaris longus. 5) Palmar cutaneous nerve of median nerve. Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 16 UPPER LIMB Muscles of the Posterior Compartment of Forearm Anterior View Posterior View Posterior View Superficial layer Deep layer Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 17  Brachioradialis (B.R.) Extensor Carpi Radialis Longus Anconeous (E.C.R.L.) UPPER LIMB Extensor Carpi Radialis Brevis (E.C.R.B.) Extensor Digitorum (E.D.) Extensor Digiti Minimi (E.D.M.) Extensor Carpi Ulnaris (E.C.U.) Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 18 UPPER LIMB Supinator Abductor Pollicis Longus (Ab.P.L.) Extensor Pollicis Brevis (E.P.B.) Extensor Pollicis Longus (E.P.L.) Extensor Indicis (E.I.) Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 19 UPPER LIMB Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 20  Objective # ( 3 ) Extensor Retinaculum  Definition: is a thickening of deep fascia holds the long extensor tendons in UPPER LIMB position.  Site: stretches across the back of the wrist.  Function: converts the posterior surface of the distal ends of the radius and ulna into six separate tunnels for the passage of the long extensor tendons.  Each tunnel is lined with a synovial sheath, which extends above and below the retinaculum on the tendons.  The tunnels are separated from one another by fibrous septa that pass from the deep surface of the retinaculum to the bones. Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 21 UPPER LIMB Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 11 UPPER LIMB Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 22 UPPER LIMB M L Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 23  Objective # ( 3 ) Extensor Retinaculum Six Separate tunnels deep to Extensor Retinaculum Structures deep to extensor retinaculum: from lateral to medial UPPER LIMB M L Extensor Contents Tunnel 1. Abductor pollicis longus 1st 2. Extensor pollicis brevis tendons 2nd Extensor carpi radialis longus and brevis tendons 3rd Extensor pollicis longus tendon 4th Extensor digitorum and extensor indicis tendons 5th Extensor digiti minimi tendon 6th Extensor carpi ulnaris tendon Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 24 UPPER LIMB M L Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 25  Objective # ( 3 ) Extensor Retinaculum Structures superficial to extensor retinaculum: from medial to lateral UPPER LIMB 1) Dorsal (posterior) cutaneous branch of the ulnar nerve 2) Basilic vein 3) Cephalic vein 4) Superficial branch of the radial nerve Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 26  Quiz The Region of the Wrist UPPER LIMB Question 1: What are the Structures on the Anterior Aspect of the Wrist? Ulna Radius Question 2: What are the Structures on the Posterior Aspect of the Wrist? Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 27  Clinical Correlation Carpal tunnel syndrome  Definition: entrapment syndrome caused by pressure on median nerve within carpal tunnel.  Cause: UPPER LIMB a) increased pressure on the median nerve caused by overuse. b) swelling of the tendons and tendon sheaths(e.g., rheumatoid arthritis).  Pathophysiology:  Increased pressure will cause venous congestion.  This will produce nerve edema and damage to median nerve itself.  Clinical Picture: o pain and pins-and-needles sensations in the distribution of the median nerve. o Weakness and loss of muscle bulk of the thenar muscles may also occur. o Gently tapping over the median nerve (in the region of the flexor retinaculum) readily produces these symptoms (Tinel’s sign).  Treatment: aim to reduce the edema. Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 28  Clinical Correlation Ganglion Cyst Definition: benign mucin-filled cyst that develops along tendons or joints UPPER LIMB Epidemiology: most common type of hand mass Location: most common at the dorsal wrist Pathophysiology: herniation of synovial membrane due to repeated trauma. Clinical features: Ulna Radius Usually asymptomatic but can occasionally cause joint pain Fluctuant, transilluminate swelling Can lead to nerve compression. Treatment: Asymptomatic: observation (often regress spontaneously) Symptomatic: aspiration or surgical resection Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 29  Case Scenario UPPER LIMB A 27-year-old left-handed woman presents with a lump on her left wrist that has been slowly increasing in size over the past 3 months. She reports that the lump is painless but causes some discomfort when she flexes her wrist. She has no history of trauma. Physical examination reveals a smooth, round, and firm 2 cm mass on the dorsum of her left wrist, which transilluminates with light. The rest of her examination is unremarkable. What is the most appropriate next step in management? A) Aspiration of the cyst B) MRI of the wrist C) Surgical excision D) Reassurance and observation E) Corticosteroid injection Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 30  Reference UPPER LIMB  Gray's anatomy for students, 3rd edition.  ISBN: 978-0-7020-5131-9  Copyright© 2015, 2010, 2005 by Churchill Livingstone, an imprint of Elsevier Inc.  Chapter 7 Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 31 UPPER LIMB Wrist Retinacula By Dr. Hassan Rezk September 7, 2024 32