M6

Case Study
Musculoskeletal 6
John Brown is a very handsome 49-year-old Estate Agent who is experiencing pain and stiffness around the right thumb for the last 6 months. There is obvious muscle atrophy around the region and he is experiencing pain when performing simple functional tasks such as movements of the thumb e.g. writing, texting, making phone calls, working at the PC etc. He is currently full time at work and lives with his wife and 4 children in a 4-bedroom house. X-rays shows no bony injury. He has been diagnosed with De Quervains disease.

Identify the pathology:
The patient has been diagnosed with De Quervains disease. De Quervains disease is an inflammation or a tendinosis of the sheath that surrounds two tendons that control movement of the thumb. The two tendons concerned are the tendons of the extensor pollicis brevis and abductor pollicis longus muscles. These two muscles, which run side by side, have almost the same function: extending both of the joints of the thumb. The tendons run, as do all of the tendons passing the wrist, in synovial sheaths, which contain them and allow them to exercise their function whatever the position of the wrist.

Causes:
-The cause of de Quervain is not known.
-Some claim that repetitive movements of the thumb are a contributing factor.
-More specifically, repetitive eccentric lowering of the wrist into ulnar deviation especially with a load in the hand such as a child

Symptoms:
-pain,
-tenderness,
-swelling over the thumb side of the wrist,
-difficulty gripping.

Atrophy is the partial or complete wasting away of a part of the body.
Causes of atrophy include:
poor nourishment,
poor circulation,
loss of hormonal support,
loss of nerve supply to the target organ,
disuse or lack of exercise or
disease intrinsic to the tissue itself.

Relative bony points of the wrist and hand
-the radial styloid process is on the lateral side of the wrist just before the wrist joint
-just above the wrist joint is the inferior radioulnar joint
-the crease that occurs when the wrist is in flexion is the radiocarpal joint
-the radius meets with the carpal bones, scaphoid and half of the lunate, the ulna meets with the other half of the lunate and the triquetral
-The carpal bones are arranged in two transverse rows between which is the midcarpal joint.
-Laterally the trapezium and trapezoid articulate with the rounded distal surface of the scaphoid
-The capitate articulates with the scaphoid and lunate in the central part of the joint
-The apex of the hamate also articulates with the lunate while its ulnar surface articulates with the triquetral
-The carpometacarpal joints are the sites of articulation between the carpal and metacarpal bones
-1st metacarpal articulates with the trapezium
-2nd metacarpal articulates with the trapezoid and also the medial side of the trapezium and the anterolateral corner of the capitate
-3rd metacarpal articulates with the capitate
-4th metacarpal articulates with the hamate but also catches the anteromedial corner of the capitate
-5th metacarpal articulates with the anteromedial surface of the hamate
-The metacarpophalangeal joint is the joint where the metacarpals join to the phalanges
-The interphalangeal joints are the joints between each phalanx.

Muscles of the fingers
Flexion - Flexor digitorum profundus
- Flexor digitorum superficialis
- Lumbricals and interossei
Extension - Extensor digitorum
- Extensor indicis and digiti minimi
Abduction - Dorsal interossei
- Abductor digiti minimi
Adduction - Palmar interossei
Opposition - Opponens digiti minimi

Muscles of the thumb
Flexion - Fexor pollicis longus
- Flexor pollicis brevis
Extension - Extensor pollicis longus
- Extensor pollicis brevis
Abduction - Abductor pollicis longus and brevis
Adduction - Adductor pollicis
Opposition - Opponens pollicis

abductor pollicis longus
It arrises from the upper part of the posterior surface of the ilna, middle third of posterior surface of radius and interosseous membrane. As it passes distally, it emerges from its deep position to lie superficially in the lower part of the forearm. The tendon forms above the wrist and passes, with that of extensor pollicus brevis, within the same synovial sheet below the extensor retinaclulum. The tendon inserts into the radial side of first metacarpal base and trapezium

-it abducts and extends thumb and abducts wrist

Extensor pollicis brevis
It lies on the lateral side of and is adjacent to extensor pollicus longus. It arises from the middle part of the posterior surface of the radius and adjacent interosseous membrane. The tendon is formed above the wrist and runs with the tendon of the abductor pollicus longus. These two tendons form the lateral boundary of the anatomical snuffbox. It attaches to the dorsal surface of the base of the proximal phalanx.
-It extends both joints of the thumb. It may also help in extending and abducting the wrist.

Both are supplied by the posterior interosseous branch of the radial nerve (C7 and 8)

Subjective assessment:
Patient would be able to move thumb and wrist
Pain when in ulnar deviation
Swelling & palpable thickening of fibrous sheath
Sharp tenderness over styloid process of radius

Objective assessment:
Muscle atrophy should be present at the thumb side of the wrist about 1 inch down from the wrist joint.

Finkelstein's test:
Finkelstein's test is used to diagnose de Quervain syndrome in people who have wrist pain.
To perform the test, the thumb is placed in the closed fist and the hand is tilted towards the little finger - ulna deviation.
Pain can occur in the normal individual, but if severe, De Quervain's syndrome is likely. Pain will be located on the thumb side of the forearm about an in inch below the wrist.

Other tests can be done e.g. grip tests

The natural history of de Quervain is not well documented. Nonetheless, there is enough observational experience to be fairly certain that it is a self-limited illness with no long-term consequence. Once resolved it rarely recurs. The illness tends to last about 1 year on average. There are no treatments that have been scientifically demonstrated to shorten the duration of symptoms. Operative release is the only known way for predictably shortening the duration of symptoms, but is elective. Surgery consists of opening the tunnels, or sheaths, that the tendons pass through. The pain usually resolves in the time that it takes the wound to heal. While patients await disease resolution, the symptoms of de Quervain can be managed with a spica splint that immobilises the wrist and thumb, anti-inflammatory pain medications (or other non-narcotic pain medications), and ice. While avoiding activities that cause pain will certainly decrease the overall amount of pain experienced, there is no evidence that this will speed recovery, or that continuing to engage in these activities will lead to any harm -- the illness is in general a harmless nuisance. It is not dangerous or neglectful to remain active in spite of the pain. The splint can be used as desired to improve function and quality of life during the illness. Specialised hand therapists (both physical therapists and occupational therapists) provide treatment in the form of splinting to immobilise and rest the wrist and thumb. Physios also advise to avoid repetitive eccentric lowering of the wrist into ulna deviation. Once pain free physios encourage therapeutic exercise such as controlled ulnar deviation.

While a decrease in ulnar deviation activity and splinting decrease the severity of the pain, there is little scientific support to suggest that these shorten the duration of the illness.

A spica splint is a type of orthopedic splint used to immobolize the thumb and/or wrist while allowing other digits freedom to move.