THE FOREARM APPROARCH by Muhammad Nadirsyah

forearm approach

1. The Forearm Approach dr. Muhammad Nadirsyah

2. The Forearm Anterior Approach to the Radius Applied Surgical Anatomy of the Anterior Compartment of the Forearm

3. Anterior Approach to the Radius The uses of the anterior approach include the following: Open reduction and internal fixation of fractures Bone grafting and fixation of fracture nonunions Radial osteotomy Biopsy and treatment of bone tumors Excision of sequestra in chronic osteomyelitis Anterior exposure of the bicipital tuberosity Treatment of compartment syndrome

4. Position of the patient on the operating table, for the anterior approach to the radius. Place the patient supine on the operating table, with the arm on an arm board Place a tourniquet on the arm Finally, supinate the forearm

5. Landmarks : Palpate the biceps tendon Palpate the brachioradialis Palpate the styloid process of the radius Incision : Make a straight incision on the anterior part of the forearm, from the flexor crease on the lateral side of the biceps down to the styloid process of the radius.

6. Distally, the internervous plane lies between the brachioradialis muscle, which is innervated by the radial nerve, just proximal to the elbow joint, and the flexor carpi radialis muscle, which is innervated by the median nerve. Proximally, the internervous plane lies between the brachioradialis muscle, which is innervated by the radial nerve, and the pronator teres muscle, which is innervated by the median nerve Internervous plane

7. Incise the deep fascia of the forearm in line with the skin incision. Identify the medial border of the brachioradialis as it runs down the forearm, and develop A plane between it and the flexor carpi radialis distally. More proximally, the plane lies between the pronator teres and brachioradialis muscles. Superficial Surgical Dissection

8. A leash of vessels from the radial artery supplies the brachioradialis. The vessels must be ligated to mobilize the brachioradialis laterally. Retract the superficial branch of the radial nerve with the brachioradialis muscle Superficial Surgical Dissection

9. Deep to the brachioradialis and the flexor carpi radialis are the supinator muscle, the pronator teres, the flexor digitorum superficialis, and, most distally, the pronator quadratus. Deep Surgical Dissection

10. With the patient’s arm in the supinated position, resect the origin of the supinator. Reflect the muscle laterally. Leave the posterior interosseous nerve in the muscle’s substance. The radial nerve enters the supinator through the arcade of Frohse (inset). Turning the forearm upward moves the nerve laterally, away from the operative field. The origin of the supinator muscle is easier to identify if the surgeon stays lateral to the biceps tendon and locates the bursa between it and the supinator. Deep Surgical Dissection

11. Turn the arm downward to identify the pronator teres muscle. Resect it along its insertion on the lateral aspect of the radius. Deep Surgical Dissection

12. Continue dissection distally to uncover the distal part of the radius. Leave the periosteum intact. Deep Surgical Dissection

13. With the arm in partial supination, remove the flexor pollicis longus and the pronator quadratus from the bone to expose the entire radius from its proximal to distal end. Deep Surgical Dissection

14. The posterior interosseous nerve is vulnerable as it winds around the neck of the radius within the substance of the supinator muscle. The key to ensuring its safety is to detach correctly the insertion of the supinator muscle from the radius. The superficial radial nerve runs down the forearm under the brachioradialis muscle. It becomes vulnerable when the “mobile wad” of three muscles is mobilized and retracted laterally Dangers Nerves

15. The radial artery runs down the middle of the forearm under the brachioradialis muscle. It is vulnerable twice during the anterior approach to the radius: During mobilization of the brachioradialis. In the proximal end of the wound, as the artery passes to the medial side of the biceps tendon. The recurrent radial arteries are a leash of vessels that arise from the radial artery just below the elbow joint Dangers Vessels

16. The anterior approach provides complete access to the entire length of the radius. The approach can be extended distally to expose the wrist joint. Although it can be extended into an anterolateral approach to the elbow and humerus, such extension rarely is required How to Enlarge the Approach

17. Applied Surgical Anatomy of the Anterior Compartment of the Forearm Two muscle groups form the musculature of the anterior aspect of the forearm: The mobile wad of three (the brachioradialis, extensor carpi radialis longus, and extensor carpi radialis brevis), which is supplied by the radial nerve, forms the lateral border of the supinated forearm; The flexor-pronator muscles, which are supplied by the median and ulnar nerves, comprise the rest.

18. Applied Surgical Anatomy of the Anterior Compartment of the Forearm The keys to the surgical anatomy of the anterior aspect of the forearm are the following three practical internervous planes that are used in operative approaches: Between the radial and median nerve Between the median and ulnar nerves Between the ulnar and posterior interosseous nerves

19. The flexor-pronator group is arranged in three layers. In the superficial layer, four muscles arise from the common flexor origin on the medial humeral epicondyle and fan out across the forearm. The superficial layer of the forearm

20. The middle layer of the forearm The deep layer of the forearm

21. Superficial Surgical Dissection and Its Dangers Superficial surgical dissection opens the plane between the mobile wad of three muscles (the brachioradialis, extensor carpi radialis longus, and extensor carpi radialis brevis) and the pronator teres muscle proximally and flexor carpi radialis muscle distally Two structures that lie under the brachioradialis muscle must be preserved during superficial surgical dissection: 1. The radial artery originates from the brachial artery in the cubital fossa. 2. The superficial radial nerve is purely sensory in the forearm.

22. Deep Surgical Dissection and Its Dangers Five muscles must be detached from the radius to expose fully the anterior aspect of the bone. From proximal to distal, they are as follows: The supinator The pronator teres The flexor digitorum superficialis The flexor pollicis longus The pronator quadratus

23. Deep Surgical Dissection and Its Dangers The posterior interosseous nerve is the motor nerve of the extensor compartment of the forearm. A branch of the radial nerve, it passes between the two heads of origin of the supinator muscle and actually may come in direct contact with the periosteum of the neck of the radius. Proximally, the median nerve usually passes between the heads of the pronator teres muscle, whereas the ulnar artery passes deep to both the heads.

24. Compartment Syndrome The forearm contains muscle compartments constrained by strong fascia. Fractures bleed, which increases the pressure within these compartments. As the pressure increases, the venous return decreases; in certain cases, the pressure becomes so high that it reduces the arterial blood supply to the muscles and creates muscle ischemia. To decompress the flexor compartments of the forearm begin by making a longitudinal incision extending for the lateral side of the elbow crease to the radial styloid process. (continued)

25. Deepen the skin incision to reveal the fascia covering the flexor muscles; the skin edges will spring apart.

26. Thank You