AT 359
Chapter 24 - The Forearm, Wrist, Hand & Fingers

BONES:
-Radius
-Ulna -does not extend down distally as far as radius does
-Carpals - 1st row: Scaphoid, Lunate, Triquetral, Pisiform (starting at thumb and moving to pinky finger)
                   2nd row: Trapezium, Trapezoid, Capitate, Hamate (starting above first row and moving to pinky finger)
-Metacarpals (1-5)
-Phalanges (distal, intermediate, proximal)

JOINTS
-Superior Radioulnar - formed between ulna and annular ligament
-Middle Radioulnar - formed between shafts of radius and ulna
-Distal Radioulnar - formed between head of ulna and notch on radius
-Radiocarpal - condyloid, permits circumduction
-Carpal - gliding
-Metacarpal (MP or MCP) - commonly fractured
-Phalangeal - DIP, PIP; thumb = IP

LIGAMENTS
-Ulnar collateral (wrist) - extends from styloid process(ulna) to pisiform/triquetral bones
-Radial collateral (wrist) - extends from styloid process(radius) to scaphoid(navicular) bone
-Transverse carpal (wrist) - forms roof of carpal tunnel (volar aspect)

MUSCLES

Thenar Emminence - part of hand (volar aspect) below base of thumb; made up of four muscles (beefy part), pg.753
Hypothenar Emminence - part of hand (volar aspect below base of pinky; made up of three muscles (beefy part)

NERVES
-Majority of wrist flexors are innervated by median nerve
-Majority of wrist extensors are innervated by radial nerve
-Hand - radial, ulnar & median
        -ulnar nerve passes between pisiform and hook of the hamate bones (Tunnel of Guyon)

BLOOD SUPPLY
-Brachial artery splits into radial and ulnar arteries at the elbow

SPECIAL TESTS
-Finkelstein's - tests for de Quervain's syndrome (tenosynovitis)
-Tinel Sign - tests for median or ulnar nerve involvement; ulnar at elbow & median at wrist
-Phalen's - tests for carpal tunnel syndrome
-Valgus/Varus/Gliding - tests ligament integrity of wrist and finger ligaments
-Lunotriquetral Ballotment - tests for instability of lunotriquetral joint
-Allen's - tests the functioning of the radial and ulnar arteries supplying the hand

FOREARM INJURIES
    -Contusions
            -MOI is blow to forearm, commonly seen in football
            -Treatment: RICE, padding for protection

    -Forearm Splints
            -much like shin splints
            -fatigue injury usually from static contractions
            -common in gymnastics
            -s/s: dull ache, tender to touch
            -treatment: strengthening of muscle or RICE depending upon season

    -Forearm Fx's
            -MOI is high trauma to forearm
            -s/s: feel and/or hear "pop", mod to severe pain, swelling, disability, possible crepitus
            -treatment: RICE, immobilization, referral to doctor

    -Colles' Fx
            -common fx to forearm involving either the distal radius or ulna
            -MOI is fall on outstretched hand most often
            -can possibly damage median nerve that passes through carpal tunnel
            -s/s: "dinner fork" deformity (hump on dorsal wrist), pain, crepitus, felt pop
            -treatment:  RICE, immobilization, refer to doctor

WRIST INJURIES
    -Wrist Sprains
            -very common in all sports
            -MOI is fall on outstretched arm/hand
            -s/s: mod to severe pain, swelling, loss of ROM
            -treatment: RICE, refer to doctor (needs to have xray done in most cases)

    -Triangular Fibrocartilage Complex (TFCC)
            -MOI is usually forced hyperextension of wrist
            -is usually associated with sprain to ulnar collateral wrist ligament
            -this injury will result in a nagging, chronic pain if not treated
            -MRI will sometimes show tear
            -conservative treatment in a cast is done first, then possibly surgery if not resolved
            -needs to be referred to hand specialist
            -hurts mainly to hyperextend with ulnar deviation

    -Tenosynovitis
            -MOI is repetitive, usually chronic condition
            -affects the sheath surrounding the tendon
            -s/s: pain on passive stretching, swelling tenderness over tendon, crepitus, can have "sticking feeling"
            -treatment: RICE, NSAID's, modify activity

    -Tendonitis
            -MOI is repetitive, chronic condition
            -similar to tenosynovitis but it affect the tendon directly
            -s/s: same as tenosynovitis but usually not as much swelling
            -treatment: same as tenosynovitis

    -Nerve Compression, Entrapment, Palsy
            -nerve becomes compressed by tight spaces between tissues
            -common sites are carpal tunnel and tunnel of guyon
            -nerve palsy is trauma directly to nerve; most common in radial and median
            -surgical decompression may be necessary
            -the following conditions can arise:
                    -ape hand - injury to median nerve
                    -bishop's hand - injury to ulnar nerve
                    -claw hand - injury to ulnar and median
                    -drop hand - injury to radial nerve

    -Carpal Tunnel Syndrome
            -located on anterior (volar) aspect of wrist
            -transverse carpal ligament creates "roof" over carpal bones
            -8 flexor tendons and the median nerve pass through this space
            -MOI is repetitive motions of wrist in sports; non-sport related is typing
            -s/s: paresthesia, tingling, weakness of thumb movement
            -treatment:  conservative at first with wrist splint, RICE, NSAID's; if not resolved, a cortisone injection and/or
                surgery is indicated

    -de Quervain's Syndrome
            -also known as "Hoffman's" disease
            -a stenosing tenosynovitis of the thumb
            -MOI is usually constant wrist movement which can irritate thumb tendons
            -aching pain which is made worse by Finkelstein's test
            -s/s: can have catching, crepitus and swelling
            -treatment: RICE, NSAID's, immobilization

    -Lunate Dislocation
            -not very common in sports
            -MOI is usually hyperextension (falling on arm)
            -lunate and scaphoid bear all of the weight when pressure is applied to the wrist in hyperextension
            -the bone usually dislocates anteriorly towards the carpal tunnel
                        -this can cause s/s of carpal tunnel syndrome
                        -there will be a noticeable hard bump over the palmar side of wrist
            -treatment:  needs to see a doctor and get it reduced, if not, the bone can necrosis

    -Scaphoid Fx
            -scaphoid is located in the anatomical snuff box
            -MOI is usually fall on outstretched hand (also lineman when blocking - hyperextension)
            -can be misdiagnosed as a wrist sprain very easily
                        -rule of thumb - if there is pain over snuff box, treat as a fx until it is ruled out
                        -the wrist is casted until further tests can be done to rule out fx
            -initial fx will not usually show up on xray
                        -bone scan is required to make diagnosis usually
            -if immobilization is not done early, the bone will not heal and will necrose, necessitating surgery
            -most scaphoid fx's do not heal well anyways, has to do with blood supply
            -some doctors will let athletes play in cast and some don't - has to do with disturbing the bone

    -Hamate Fx
            -commonly the fx is at the hook
            -MOI is usually from a fall but can happen when athlete is holding an instrument
            -s/s: pain, swelling, weakness
            -treatment:  xrays need to be taken, can be put in cast and heals well

    -Wrist Ganglion
            -also known as "bible bump"
            -is actually a synovial cyst or a herniation of a tendon sheath
            -s/s: bump on dorsal wrist(can also be on palmar side), pain on use, bump may feel hard or soft
            -treatment: pressure pads and aspiration used to be methods of choice but they don't prevent it from
                    recurring; surgical excision is the most effective means of treatment

HAND/FINGER INJURIES
    -Finger Contusions
            -can develop into hemorrhaging underneath the nail bed
            -this creates a lot of pressure underneath the nail thus producing a lot of pain
            -pressure must be released by a nail drill or hot paper clip

    -Trigger Finger or Thumb
            -MOI is usually repeated movements of hand and wrist
            -most commonly affected are wrist extensors
            - is actually a tenosynovitis which can develop into a stenosing synovitis
                    -this means the space for the tendon to pass through the sheath is a lot more narrow and gets "caught"
            -when the finger trys to extend it "sticks"
                    -when a nudge is given to the finger, it pops or snaps back to extension
            -treatment: same as tenosynovitis conditions

    -Mallet Finger
            -also known as baseball or basketball finger
            -MOI is forced flexion of DIP when finger is in full extension
            -the tendon is avulsed away from the bone thus resulting in not being able to fully straighten tip of finger
            -s/s: pain at DIP joint, unable to extend finger,
            -treatment: RICE, finger splint keeping DIP joint straight for 6-8 weeks, xray for fx

    -Boutonniere Deformity
            -MOI is from a force applied to tip of finger placing the DIP into extension and the PIP into flexion
            -the central extensor tendon ruptures and splits down the sides of the PIP joint
            -s/s: severe pain, inability to extend DIP joint, swelling, point tenderness, deformity
            -can occur from dislocation at PIP joint as well
            -treatment: Ice, splint PIP joint into extension to prevent permanent deformity (5-8 wks), stretching of DIP joint

    -Jersey Finger
            -rupture of flexor digitorum profundus tendon from it insertion on the distal phalanx
            -common MOI is grabbing someone's jersey (forced extension of joint while flexing)
            -s/s: cannot flex finger, pain, swelling
            -treatment: must see doctor ASAP, needs repair but it still might rupture after repair, results of surgery on
                        flexor tendons do not have good results very often; it will not heal on its own

    -Dupuytren's Contracture
            -MOI is still unknown
            -nodules develop in palmar aponeurosis that limit finger extension and cause a flexion deformity
            -s/s: flexion deformity most often in ring finger, finger cannot be extended
            -this is a flexion contracture and the nodules must be removed surgically to have any chance at recovery
       
    -Gamekeeper's Thumb
            -sprain to the ulnar (medial) collateral ligament of the MCP joint of the thumb
            -MOI is forceful abduction of proximal phalanx with hyperextension
            -s/s: pain over ulnar collateral ligament, weakness of pinch strength, swelling over thenar emminence
            -treatment: if unstable, casting may be required; refer to doctor for xrays to rule out fx; splint or cast for
                    about 3 weeks until pain free and protect by taping (spica or check reins)

    -Interphalangeal Joint Sprains
            -MOI is usually force applied to tip of finger forcing distal finger to move in a valgus or varus motion
            -damages collateral ligaments and/or volar plate
            -s/s: pain/laxity on valgus/varus stress tests, point tenderness
            -treatment: RICE and splint finger in 30-40 degrees of flexion with buddy taping

    -Swan Neck Deformity and Pseudoboutonniere Deformity
            -volar plate of PIP is commonly injured
            -MOI is hyperextension of finger
            -distal tear will cause swan neck and proximal tear will cause pseudoboutonniere deformity
            -s/s: pain, swelling, extra hyperextension of PIP joint
            -treatment: RICE, splinting at 20-30 degrees of flexion for 3-4 weeks with buddy taping

    -Metacarpal Fx's
            -common in high contact and collision sports such as football
            -MOI is either an axial force (hitting a wall with fist) or compression force (being stepped on)
            -common fx is boxer's fx (4th and 5th metacarpal)
            -s/s: may have rotational deformity along with shortening (requires surgery), pain, swelling
            -treatment: RICE, xrays, cast/splint for 4-6 weeks (boxer fx splint/cast is called an ulnar-gutter cast)
           
    -Bennett's Fx
            -occurs at CMC joint
            -MOI is axial abduction force on thumb usually with a closed fist
            -s/s: pain, swelling over base of thumb, thumb may appear shortened
            -treatment: refer to doctor for xrays; will require surgery

    -Finger Sprains/Dislocations/Fx's
            -regardless of phalanx always treat same way - immobilize and get to doctor for reduction
            -always observe 3 things when evaluating hand/finger injuries:
                    1)knuckles with clenched fist
                            -looking for dropped knuckle which means an unstable fx (requires surgery)
                    2)lightly close fist with fingertips pointing towards carpal tunnel
                            -looking for all fingers to point to one point on forearm (rotational instability)
                    3)have athlete touch all fingertips to their thumb on same hand

    -Fingernail Deformities
            -scaling or ridging = psoriasis
            -ridging and poor development = hyperthyroidism
            -clubbing and cyanosis = congenital heart disorders or respiratory disease
            -spooning or depression = chronic alcoholism or vitamin deficiencies

Web Sites for further study/learning:
www.nlm.nih.gov/medlineplus/handwristarminjuriesanddisorders.html - Medline Plus

www.aota.org - American Occupational Therapy Association

www.hand-surg.org - American Society for Surgery of the Hand

www.worldortho.com - World Ortho

www.medmedia.com/med.htm - Wheeless' Textbook of Orthopaedics

www.sportsmed.org - American Orthopaedic Society for Sports Medicine