Anatomy Of The Pronator Quadratus - Everything You Need To Know - Dr. Nabil Ebraheim скачать в хорошем качестве

Anatomy Of The Pronator Quadratus - Everything You Need To Know - Dr. Nabil Ebraheim

Dr. Ebraheim’s educational animated video describes the anatomy of the pronator quadratus muscle. The pronator quadratus is different from the pronator teres and the pronator syndrome. First let’s learn what pronator syndrome is: it is a compression of the median nerve at the level of the elbow, it is not a muscle, the median nerve passes between the two heads of the pronator teres muscle. If you compress the median nerve at the wrist it will be called: carpal tunnel syndrome, if you compressed the median nerve at the elbow, it will be called: pronator syndrome. The pronator quadratus is a square muscle that pronates the forearm; it helps the pronator teres in that function. Pronator quadratus is: pronation by square muscle. Origin: it arises from the distal fourth of the anterior surface of the ulna. Insertion: into the distal fourth of the anterior surface of the radius. Function: pronates the forearm, the deep fibers bind the radius and the ulna together. How can you test for the pronator quadratus muscle? The pronator quadratus can be tested with the elbow held in flexion to neutralize the humeral head of the pronator teres muscle, then test the pronation against resistance. Innervation: the anterior interosseuos nerve, which is a branch of the median nerve. If you have compression of the anterior interosseous nerve, the following muscles will be affected: 1- The flexor pollicis longus. 2- The pronator quadratus. 3- The flexor digitarum profundus to the index and to the middle finger. The volar aspect of the arm is arranged into two groups: 5 superficial group of muscle. 3 deep group of muscles. The pronator quadratus muscle lies in the deep compartment of the volar muscles, this deep compartment is important when you do fasciotomy of the forearm, so when you do the volar fasciotomy of the forearm, we need to open the superficial layer and the deep layer. In Distal radial fractures in children when you cannot reduce them, especially if they are displaced salter fractures, usually the inability to reduce them is due to blockade of the reduction by the periosteum or by the pronator quadratus., in these cases you will do open reduction and internal fixation. Another important point: is when you do open reduction and internal fixation of the distal radius, the pronator quadratus lies directly over the distal radius and it must be peeled off or retracted to be able to reach the bone, for example: to put a plate on the bone. Another topic is the flexor pollicis tendon rupture associated with volar plating. Plating of the distal radius fracture may cause rupture of the tendon due to rubbing of the tendon against the plate. Some people believe that if you restore the pronator quadratus to its position, it will protect the overlying muscles (which are the flexor muscles) from rupture, so the pronator quadratus will be a layer that will prevent rubbing of the flexor tendons against the edge of the plate. You still need to tell your patient to let you know if they feel any irritation in the tendon of the thumb, because the plate maybe rubbing against these tendons. As you can see, the small square muscle that pronates the forearm, has a lot of clinical significance. What is the Parona’s Space? It is a potential space for spreading of the infection between the hand and the forearm. Acute compartment syndrome of the forearm can occur secondary to infection in the Parona space that can happen from the fingers or the hand. The Parona’s space facilitates the communication between the radial and the ulnar bursa. The boundaris of this space: • Pronator quadratus (dorsal) • Flexor tendons (volar) • Flexor carpi ulnaris (ulnar side) • Flexor pollicis longus (radial side) How is the infection spread? The radial bursa and the flexor sheath of the thumb are continuous. The ulnar bursa and the flexor sheath of the small fingers are continuous. 50% of the radial and the ulnar bursa communicate at the level of the wrist. So clearly, a distal infection can extend to the Parona’s space. Infection of one finger may lead to direct infection of the sheath on the opposite side of the hand, resulting in a horse shoe abscess. Become a friend on facebook:   / drebraheim   Follow me on twitter: https://twitter.com/#!/DrEbraheim_UTMC Donate to the University of Toledo Foundation Department of Orthopaedic Surgery Endowed Chair Fund: https://www.utfoundation.org/foundati...