Ses 10 Hand Injuries Flashcards
Scaphoid fractures notion
Mechanism - fall onto an outstretched hand
(resulting in hyperextension and impaction of the scaphoid against the rim of the radius.
Symptoms- pain in snuffbox region.
Passive range of motion dec
Swelling around radial wrist
Diagnosis - follow up X-rays after 10 days as fracture line will be more visible. Then CT or MRI.
Complications -blood supply is retrograde and tenuous so fracture through the waist can cause avascular necrosis.
Mal-union and non-union
Secondary OA
Colles’ fracture notion
What is it - extra-articular fracture of the distal radial metaphysis, with dorsal angulation and impaction.
Mechanism - high impact trauma eg skiing or osteoporosis (so post-menopausal women). fall onto an outstretched hand with a pronated forearm and wrist in dorsiflexion.
Symptoms- painful, deformed, swollen wrist.
Diagnosis- dorsal angulation and impaction on X-ray esp laterally.
Complications - malunion (dinner form deformity)
Median nerve palsy so carpal tunnel syndrome
Secondary OA
Tear of EPL tendon
Smith fracture
What - distal radius with palmar angulation of the distal fracture fragments. extra-articular.
Mechanism- fall onto the dorsum of a flexed wrist or a direct blow to the back of the wrist.
Complications- malunion and palmar displacement means garden spade deformity.
Leads to carpal tunnel.
Rheumatoid arthritis of the metacarpophalangeal joints (MCPJ) and interphalangeal joints (IPJs). Notion
Symptoms - Multiple joints affected in symmetrical distribution.
pain and swelling
erythema
Stiffness worse after inactivity
Carpal tunnel syndrome due to synovial swelling so compression of median nerve.
Fatigue and flu-like
Diagnosis from X-ray on notion
2 deformities:
swan neck - at PIPJ, tissues on palmar aspect become lax so joint is hyperextended. At distal there is rupture of extensor digitorum tendon so mallet deformity - flexion.
Boutonniere -MCPJ hyperextended, PIPJ flexed, DIPJ hyperextended.
Inflammation of PIPJ means rupture of central extensor digitorum. Lateral extensor digitorum goes to palmar surface and flex. Also hyperextend DIPJ.
Psoriatic arthropathy
What - red, flaky patches of skin covered with silvery scales.
small joints of the hands and feet - DIPJs.
asymmetrical oligoarthritis (develops in one joint at a time).
Symptoms - fusiform (sausage) swelling of digits - dactylitis.
Stiffening.
widespread joint destruction called arthritis mutilans.
nail lesions, such as pitting (hyperthyroidism and fungal as well) and
onycholysis (separation of the nail from the nail bed)
Classic sign of 3 - Osteoarthritis of the 1st CMC joint, OA of DIPJs and Heberden’s nodes
Most common is CMC ( esp in women over 40).
Pain at base of thumb which is worsened by movement
Stiffness after rest
Swelling
first metacarpal subluxes in an ulnar direction
OA of DIPJ - Over 50 - stiffness, reduced range of movement, and swelling
HN = it is a cystic swelling with hyaluronic acid on dorsolateral
aspect of DIPJ. Then left with osteophyte.
Familial + middle age + women
Chronic swelling, Sudden pain, Swelling, Loss of manual dexterity.
When it affects PIPJs it is Bouchard’s nodes.
Carpal tunnel syndrome
It is the compression of the median nerve as it passes through the carpal tunnel from the forearm into the hand - distal aspect of wrist.
Causes - obesity, repetitive wrist work, pregnancy, rheumatoid arthritis and hypothyroidism.
Symptoms- parasthesia in first 3 and a half fingers (not palm as that branch is proximal to carpal tunnel).
Worse at night as wrist is flexed.
Muscle weakness and atrophy of the thenar muscles.
Cannot carry out daily activities such as driving or buttoning.
Complications- ischaemia, focal demyelination, and axonal loss of median nerve due to compression.
Ulnar nerve compression in Guyon’s canal
Guyon’s canal - ulnar nerve passes radial to pisiform on palmar side of flexor retinaculum.
Parasthesia in ring and little fingers, weakness of intrinsic muscles of the hand ( adductor pollicis and the palmar and dorsal interossei ).
Dupuytren’s contracture
There is localised
contracture of the palmar aponeurosis leading to a flexion of the adjacent fingers.
Autosomal dominant.
Nodule in palm. Myofibroblasts within contract so tight cords in palmar fascia. Overlying skin, proximal fascia and skin of fingers also involved. Fixed flexion.
Usually ring and little finger.
Risk factors - male, 40-60, Northern European, family history.
Type 1 diabetes
HIV
Smoking
Trauma to hand or fingers
Froment’s Sign
Froment’s sign is a test for ulnar nerve palsy, specifically paralysis of the adductor pollicis.
A positive test is when the patient is unable to adduct the thumb. Instead, they flex the thumb at the interphalangeal joint to try to maintain a hold on the paper.
High median nerve injury notion
Cause:
Supracondylar fracture
When patient asked to make fist = hand of benediction:
Normal flexion of medial 2 fingers
Index and middle finger fully extended due to radial head of FDP and all FDS paralysis.
Thumb adducted, extended and externally rotated due to paralysis of APB, FPL (also superficial head of FPB), OP.
Supination due to PQ and PT paralysis
Sensory loss in radial palm + 3.5 digits + fingertips on dorsum of index and middle finger.
At rest = ape hand deformity
Thenar muscle wasting causes adducted and externally rotated thumb
(Also can flex at MCPJ due to deep head of FPB but not IPJ due to FPL paralysis)
Low median nerve injury
Causes - penetrating injury to wrist or compression in carpal tunnel
Ape hand deformity due to thenar muscle wasting
High ulnar nerve injury - less prominent claw
Medial epicondylar fracture or compression in cubital tunnel
Hyperextension of MCPJs and flexion of PIPJs (medial lumbricals paralysis - unopposed action of ED and FDS) but no flexion in DIPJs due to FDP paralysis.
Low ulnar nerve injury - claw hand
Hyperextension of MCPJs and flexion of PIPJs and DIPJs
Radial nerve injury - spiral groove
Cause - mid-humeral shaft fracture
Extension intact because long and lateral head of triceps have innervarion before spiral groove.
Posterior cutaneous nerve intact.
Medial head of triceps and lower lateral cutaneous nerve also proximal to fracture so intact.
Wrist drop due to loss of ECRL, ECRB.
Unopposed flexion of all fingers due to loss of ED, EDM, EDI, EPL, EPB.
Loss of sensation in dorsum of 3.5 digits except fingertips.
