Review of the Upper Limb-I. Joints, muscles and their functions. Frequent injuries and their consequences.

Dr. Magdolna Kovács Dept. of Anatomy April 2006.

1. Functional aspects of muscles and joints -from shoulder to wrist 2. Frequent disorders and injuries.

Shoulder dislocation

Humeral head dislocated from the glenoid fossa of the scapula due to shoulder joint capsule laxity

Shoulder dislocation: x-ray and graphical representation.

Dislocation of shoulder joint - Mostly anterior or inferior dislocation Causes: Falling on an outstretched arm A direct blow to the shoulder area Forceful throwing, lifting, or hitting Force applied to an outstretched arm as in a football tackle Brachial plexus paralysis

This inferior dislocation of the shoulder was due to brachial plexus paralysis.

Shoulder Anterior Dislocation

Rotator cuff stabilizes the shoulder joint Medial rotators in front (below)

Lateral rotators behind !!!

Infraspinatus Teres minor

Supraspinatus –above Deltoid –around

Subscapularis Teres major

Relocation of anteriorly dislocated humeral head

Muscles of the back acting on the shoulder girdle (sterno-clavicular joint)

Elevation -1a, 2, 3, 4 Depression -1b Backword movement -1, 3, 4 Forword movement –pectoralis minor Rotation of the clavicle

Rhomboideus minor and major

Levator scapulae Trapezius

2

1a

3 4

1b

Teres major Latissimus dorsi

Thoracolumbar fascia

Brachial plexus lesions Thoracicus longus Dorsalis scapulae Suprascapularis Subclavius

Upper lesion 60% Erb palsy

Lower lesion 5% Klumpke palsy

Movements have to be checked for Erb’s palsy Abduction Deltoid Supraspinatus Abduction Elevation

Elevation Serratus anterior

Backword movement of scapula Trapezius Rhomboideus

Anteflexion Coracobrachilais Anterior part of Deltoid + supination of forarm Biceps, supinator

Adduction -anteflexion Pectoralis major Coracobrachialis + Flexion of forarm Biceps, brachialis

Upper lesions of brachial plexus – Erb’s palsy

Extensive traction or tearing of C5-C6 roots of brachial plexus innervating shoulder muscles (lateral rotators, Deltoid) and flexors on the arm (biceps, Brachialis, coracobrachialis).

Birth injury –shoulder dystocia with brachial plexus injury caused by sacrum or symphysis Due to an inbalance in muscle tone, arm is medially rotated, adducted and retroflexed, forarm is pronated.

Dystocia = abnormal (pathological) labour

„Porter/waiter tip” position

An experienced and conscientious practitioner, who is familiar with Shoulder Dystocia and how to work with it, should be able to prevent brachial plexus injuries to your baby.

Torticollis can also cause brachial plexus damage

Surgery

1. Decompression of axillary nerve 2. Transfer of medial rotators to the insertion of lateral rotators

„Winging” scapula

Isolated long thoracic nerve injury resulted in Serratus anterior paralysis

No elevation of the Arm (above horizontal) is possible

Radial nerve injury by humerus fracture

Deep branch of radial nerve Radial nerve In its spiral Sulcus on humerus

Wrist drop

Radial nerve injury with surgical graft repair Pre-operative condition

A. A segment of the sural nerve is harvested from the leg

B. The harvested nerve is sutured in place

Post-operative condition

Radial nerve reconstruction Postoperative function

Extension at the elbow and dorsal flexion at the wrist joint

Ulnar nerve injury

Cervical rib

Unlar nerve injury– clow hand Ulnar Nerve Entrapment An injury to the elbow such as a dislocation or fracture can tear Extension at the metacarpo-phalangeal or inflame the ulnar nerve, flexion at the interphalangeal joints – which extends down the arm, interosseus and lumbrical paralysis across the elbow, and into the hand. The inflamed nerve can swell and become trapped, causing a condition called ulnar nerve entrapment or cubital tunnel syndrome.

Cubital tunnel syndrome

There are several possible causes of cubital tunnel syndome. Frequent bending of the elbow such as pulling levers, reaching, or lifting are common sources of problems. Even anatomy may play a role. The ulnar nerve actually stretches several millimeters when the elbow is bent. Sometimes the nerve will shift or actually snap over the bony medial epicondyle causing irritation.

Tapping on the nerve as it passes through the cubital tunnel will cause an electric shock sensation down to the little finger. This is commonly referred to as a Tinel's Sign.

Treatment of Cubital tunnel

Surgery begins by releasing the ulnar nerve as it passes through the cubital tunnel

The nerve is then moved into this pouch

The flexor muscles are then released to make a small pouch to move the nerve into.

and the pouch is closed to create a new tunnel for the ulnar nerve.

Median nerve injury –suicide

Monkey hand A patient with median nerve palsy is illustrated with wasting of the thenar muscles No opposition of thumb is possible

Carpal Tunnel Syndrome

Causes: Through the small carpal tunnel passes the nine flexor tendons, along with the median nerve.

Any pressure exerted onto this area will squeeze the median nerve causing pain, and numbness to the hand and wrist. For example: repetitive wrist or hand motions, such as working at a computer terminal; playing a musical instrument, sports, or even knitting, can cause swelling in the carpal tunnel.

Carpal Tunnel Syndrome is the #1 Repetitive Motion Injury in the United States. It is a condition where the median nerve being pressed at the wrist, causing pain in the wrist and numbness in the thumb and first two fingers.

When the flexor muscles, or the thumb muscles, are in spasm they put excessive pressure, or pull, on the carpal tunnel and put pressure on the median nerve.

When the opponens pollicis muscle contracts it pulls the thumb towards the palm. This movement causes the flexor retinaculum to press down onto the median nerve. If either the thumb muscle, or the flexor muscles, are tight, this movement will cause your thumb and fingers to go numb.

Symptoms of the Carpal Tunnel syndrome

Conservative treatment: Splints (rögzítőkötés) are used to keep the wrist and hand in neutral position Anti-inflammatory medications are commonly used to reduce inflammation and decrease pain.

1. Endoscopic surgery or 2. Open tunnel surgery

Both surgeries are performed to relieve pressure on the median nerve in the carpal tunnel. Endo is a refinement of the Open Tunnel technique. Since Endo is not as invasive a procedure [smaller incision] as Open Tunnel is, then recovery time is shorter for Endo (2-4 weeks for Endo) than for Open Tunnel (4-6 weeks or more).

Endoscopic surgery A small scalpel is inserted under the skin through the carpal tunnel to cut the roof of the tunnel [transverse ligament] from the inside out. The wrist’s exterior is not cut open as it would be in the Open Tunnel procedure.

Open tunnel surgery: Here, the transverse ligament is split open which theoretically relieves pressure on the median nerve from an overcrowded carpal tunnel.

Clinical Example: Deep infection following open carpal tunnel release

Elective hand surgery has a very low risk of infection. However, when infections do occur following surgery in the moving parts of the hand, the problem can be catastrophic, because the slippery synovial tissues which cover the inner moving surfaces both allow infection to grow and allow it to spread easily to other parts of the hand. She was treated with repeated radical debridement and intravenous antibiotics. Her infection was cured, but she was left with stiffness of the small finger.