Wrist and Hand Anatomy and Injuries

1. Wrist and Hand Anatomy and Injuries Morgan Scott, MS, ATC, LAT

2. Unit Objectives • Understand the basic anatomy of the wrist and hand • Explain various types of injuries that occur • Understand the common mechanisms of injury • Understand the signs and symptoms of the various types of injuries

3. Bony Anatomy of Wrist and Hand

4. Carpal Bones • Pneumonic for carpal bones Of the wrist • Some (Scaphoid) • Late (Lunate) • Trainers (Triquetrium) • Practically (Pisiform) • Taped (trapezium) • Tommy’s (trapezoid) • Clean (Capitate) • Hand (Hamate)

5. Metacarpals & Phalanges • There are 5 metacarpal bones (numbered I-V, starting with the Thumb) • There are 14 Phalange Bones • The thumb is the only finger with 2 phalanges

6. Wrist and Hand Joints • The Carpometacarpal Joint is located where the carpal bones meet the metacarpals (hand) • The Metacarpal phalangeal joint is located between the hand and the fingers • The Interphalangeal Joints are between each phalange (if you look at your fingers, everywhere you have creases, there is a joint)

7. Wrist Muscle Anatomy • The wrist and hand movements are controlled by many different muscles. • The flexor muscle groups are located on the anterior surface of the forearm. • The extensor muscle groups are located on the posterior aspect of the forearm.

8. Wrist Ligaments • Most injuries to the wrist and fingers are sprains. • Of major interest in wrist injuries are: • Ulnar Collateral Ligament: extends from ulna to the pisiform • Radial Collateral Ligament: extends from the radius to the scaphoid • Transverse Carpal Ligament: crosses the volar aspect of the carpal bones • One common misconception about sprains of the fingers is that they must be pulled back into place. This is NOT true!

9. Phalangeal Joints • Each phalangeal joint has an articular capsule that is reinforced by collateral and volar ligaments. • The interphalangeal joints are of hinge type, permitting only flexion and extension. • Distal Interphalangeal • Proximal Interphalangeal (closer to wrist)

10. Neurovascular Supply • Ulnar Nerve: little finger, sensory to dorsal, digits 4-5 • Median Nerve: volar hand and fingers, thumb opposition, finger flexors • Radial Nerve: Dorsum of hand, extensor muscles

11. Palpations • Scaphoid • Trapezoid • Trapezium • Lunate • Capitate • Triquetrium (triquetral) • Pisiform • Hamate • Metacarpals • Proximal phalanges of the fingers • Middle phalanges of the fingers • Distal phalanges of the fingers • Proximal phalange of the thumb • Distal phalange of the thumb • Ulnar Collateral Ligament of the wrist • Radial collateral Ligament of the wrist

12. Preventing Wrist Injuries • Protective equipment can be used to prevent injury. Some items include; • Braces • Tape • Gloves • Padding • Be aware of the rules of the sport. Some sports prohibit the use of hard substances such as braces or only allow protective equipment with a doctors note.

13. Evaluation of Hand and Wrist Injuries • History: Ask questions? • General Inspection • Posturing of the hand • Gross deformity • Palmar creases • Areas of cuts of scars • Inspection of Hand and wrist

14. Wrist/ Forearm Fractures • Fractures of the forearm are common in children and youths. • Etiology: direct blow or fall on outstretched hand. • Direct blow to forearm usually results in ulna fracture. • Signs and symptoms: audible crack, pain, swelling disability. • Management: RICE, Splinting, Refer to doctor.

15. Colles’ Fracture • Most common types of forearm fractures. • Involve lower end of radius or ulna. • Mechanism: FOOSH • Less common is the reverse of Colles’ Fracture; Mechanism is fall on back of hand. • S/S: forward displacement/ visible deformity (silver fork deformity) • Management: Cold compress, spilint, sling, refer for X-rays. • No complications: athlete will return in 1-2 months

17. Wrist Sprains • Most common wrist injury which occurs from overuse, falls, and forceful twisting motion. • Signs and symptoms: Pain, decreased ROM, decreased grip strength, swelling • Management: RICE, Reestablish ROM and strength, Tape or brace on return to activity for support • ** The main support for the wrist is derived from posterior and anterior ligament which transport vessels to the carpal bones and stabilize the joint. • Therefore, repeated sprains may disrupt circulation.

18. Critical Thinking • An athlete who sustained a major wrist sprain complains of a decrease in hand circulation. • How should this injury be evaluated for a circulation problem?

19. Allen’s Test • Allen’s test is used to determine the function of the radial and ulnar arteries supplying the hand. • The athlete is instructed to open and close the hand in a tight fist 3 or 4 times. • While the athlete is holding the last fist, the ATC places firm pressure over each artery. • The athlete is instructed to open their hand. The palm will be a white color. • One artery is then released, if normal the hand will become instantly red.

20. Triangular Fibrocartilage Complex Injury (TFCC) • The TFCC is a fibrous structure that seperates the radiocarpal and radioulnar joints in the wrist. • It is the major ligamentous stabilizer of the distal radioulnar joint. • The TFCC functions like the meniscus of the knee. • It is prone to cartilage tears that could cause wrist pain and clicking. Similar to meniscus tears.

21. Triangular Fibrocartilage Complex Injury (TFCC) • Etiology: forced hyperextension of the wrist which compresses the TFCC between the radioulnar joint and carpal bones. • S/S: It is common for an athlete to not report this injury immediately. Pain along ulnar side of wrist, clicking or catching, swelling. • Management: refer to Doctor. • Immobilized for 4 weeks

22. Carpal Tunnel Syndrome • Located on anterior aspect of wrist. • Floor: carpal bones • Roof: transverse carpal ligament • Many structures go through this space, such as: • 8 finger flexor tendons, median nerve • Etiology: results from inflammation of tendons and synovial sheaths which ultimately leads to compression of median nerve. • Repeated wrist flexion or direct trauma

23. Carpal Tunnel Syndrome • S/S: Compression of median nerve will result in both sensory and motor defecits. • Sensory changes: tingling, numbness, and paresthesia over the thumb, index and middle fingers and palm of hand. • Motor changes: weakness in thumb movement • Management: RICE, immobilize and NSAIDs. If condition persists injection with corticosteriod and possible decompression of the transverse carpal ligament

24. Critical Thinking • A shot-putter is beginning to feel tingling, numbness, and paresthesia in the thumb, index, and middle fingers and palm of right hand. • The athlete is demonstrating a carpal tunnel syndrome. What factors could produce this problem?

25. Dislocation of the lunate bone • Dislocations are infrequent in the wrist during athletic competition. • The lunate bone is the most commonly dislocated. • Mechanism: Forceful hyperextension, FOOSH. • The lunate is usually dislocated anteriorly. • S/S: Pain, swelling, and difficulty flexing wrist and fingers • Management: Refer to doctor, if not detected early enough, bone deterioration may occur.

27. Scaphoid Fracture • Most frequently fractured of the carpal bones. • Mechanism: FOOSH which compresses the scaphoid bone between the radius and second row of carpal bones. • Without proper splinting, the fracture often fails to heal because of an inadequate supply of blood, thus degeneration and necrosis occur. • S/S: Swelling in area of carpal bones, severe point tenderness in anatomical snuff box.

28. Scaphoid Fracture • Management: apply cold and splint, refer for x-ray. Immobilization usually takes place for 6 weeks and is followed by strengthening. The wrist also need protection against impact loading for 3 months.

29. Hamate Fracture • Mechanism: FOOSH but more commonly from contact while the athlete is holding a tennis racket, baseball bat, lacrosse stick, hockey stick or golf club. • S/S: wrist pain, weakness, and point tenderness. • Management: Casting. The hook of the hamate can be protected by a donut shaped pad to take the pressure off the area.

31. Wrist Ganglion • Wrist ganglion is a synovial cyst which is considered to be a herniation of the joint capsule or synovial sheath. • S/S: occasional pain with lump at the site. May feel soft, rubbery or very hard. • Management: Aspiration or digital pressure and pressure pad. Ultrasound can be used to reduce the size of the cyst.

33. Critical Thinking • A soccer player falls on the outstretched left hand, causing a compression force to the scaphoid bone between the radius and second row of the carpal bones. • What wrist injury is most likely to have occurred?

34. Group work • Get into 3 groups. • Pick a wrist injury • Draw wrist/ Hand on poster. • Emphasize area of injury • Write on poster: Mechanism, Signs and Symptoms, Management.

35. Trigger Finger • Etiology: Inflammation of the tendon sheath which leads to swelling, crepitis, and painful movement. • Most commonly affected are the extensor tendons. • S/S: Complains that when the finger or thumb is flexed, there is resistance to reextension; which produces snapping. • Management: Corticosteriod and splinting.

37. Mallet Finger • Sometimes called baseball finger or basketball finger. • Etiology: Caused by blow from a thrown ball that strikes tip of finger; jamming and avulsing the extensor tendon. • S/S: Pain at DIP joint, athlete unable to extend the finger, carrying it at a 30 degree angle. • Management: RICE, if not fractured, the distal phalanx should be splinted immediately in extension.

39. Boutonniere Deformity • Etiology: The boutonniere or buttonhole deformity is caused by a rupture of the extensor tendon to the middle phalanx. Trauma occurs to tip of finger which forces the DIP joint into extension and PIP joint into flexion. • S/S: Severe Pain and inability to extend DIP joint, swelling, obvious deformity. • Management: Cold application followed by splinting.

41. Jersey Finger • Etiology: Rupture of the flexor tendon from its insertion on the distal phalanx. • This condition most often occurs on ring finger. • S/S: The tendon is no longer attached to the distal phalanx, the DIP joint cannot be flexed. • Management: If the tendon is not repaired surgically, the athlete will never be able to flex the DIP, causing grip weakness.

43. Critical Thinking • A baseball catcher receives a pitch that jams and avulses the extensor tendon of the DIP joint of the second finger. • How should this condition be managed?

44. Wrist & Finger Review Questions • Describe the Colles’ fracture of the forearm—Cause, appearance, care. • Describe the mechanism, symptoms, and signs of a wrist sprain. • What healing problems occur with a scaphoid fracture? • Describe the circumstances that can produce a mallet finger and boutonniere deformity in baseball players. What care should each condition be given?