Conditions of the Hand Flashcards
What are the six most common positions of the hand?
What is a FOOSH?
A Fall On Outstretched Hand
Scaphoid Fracture
- 70-80% of fractures od the carpal bomes and 10% of all hand fractures
- Adolesecent sand yound adults following FOOSH (hyperextension and impact of scaphoid against radius)
- Pain in anatomical snuffbox - worse when moving
- Swelling around radial and posterior aspect of the wrist
- Most commonly occur at waist
- Delayed diagnosis common as X-ray straight after may not show it.
- Should do follow up after 10-14 days as fracture line becomes more visible after some bone resorbtion.
- If still not clear, use CT or MRI.
- Risk of avascular necrosis because of the retrograd blood supply.
- High risk of non-union, malunion, avascular necrosis and late complications of carpal instability and secondary osteoarthritis.
Colles’ Fracture
- A Colles’ fracture is an extra-articular (not in wrist joint) fracture of the distal radial mataphysis, with dorsal angulation and impaction.
- Associated ulnar styloid fracture in up to 50% of cases
- Most common distal radial fracture
- Common in osteoporotic patients and post-menopausal women
- If younger, high impact trauma
- FOOSH with pronated forarm and wrist in dorsiflexion
- Present with painful, deformed and swollen wrist
- Treated by reduction and immobilisation in a cast.
- Complications include:
- Malunion - dinner fork deformity
- Median nerve palsy and post-traumatic carpal tunnell syndrome
- Secondary osteoarthritis
- Tear of extendor pollicis longus tendon,
Smith Fractures
- Fracture of the distal radius with volar (palmar) angulation of the distal fracture fragments.
- 85% are extra-articular so “reverse colles”
- Less than 3% of all fracturs of the radius and ulna
- Young males and elderly femailes
- Fall onto flexed wrist or direct blow to the back of the wrist
- Malunion with resiual volar displacement of distal radius results in a garden spade deformity - cosmetic.
- Garden spade deformity narrows and distorts the carpal tunnel so can result in carpal tunnel syndrome.
Rheumatoid Arthritis of MCPJ and IPJs
- Autoimmune disease in which anutoantibodies (Rheumatoid factor) attack the synovial membrane. Inflammed cells proliferate to form a pannus which pennetrates through the cartilage and bone leading to joint errosion and deformity.
- Described as symmetrical polyarthritis - difficult to diagnose as no ‘normal hand’
- Present with:
- Pain and swelling of joints and fingers
- Erythema (redness) overlying the joints - imflammation
- Stiffness - worse in the morning or innactivity
- Carpal tunnel syndrome
- Fatigue and flu-like symptoms.
- Rheumatoid nodules are a late feature
What are the X-ray features of Rheuratoid arthritis?
- Joint space narrowing
- Periarticular osteopenia
- Juxta-articular (marginal) bony erosions (in non-cartilage protected bone)
- Subluxation (partial dislocation) and gross deformity
Swan neck deformity
- A swan neck deformity occurs when the PIPJ hyperextends and the MCPJ and DIPJ are flexed.
- Tissue on the vilar (palmar) aspect of PIPL becomes lax because of adjacent sinovitis
- PIPJ becomes hyperextended because of imbalance between the muscle forces acting on this joint
- At DIPJ either elongation or rupture of the insertion of extensor digitorum into the base of the proximal phalanx - mallet deformity.
Boutonniere deformity
- Opposite to swan neck
- MCPJ and PIPJ are hyperextended while the PIPJ is flexed,
- Inflammation in PIPJ = lengthening (or rupture) of the central slip of extensor digitorum at its insertion into the base of the middle phalanx on the dorsal surface of the finger.
- The lateral bands slip down the sides of the finger - go onto palmar surface at level of PIPJ - act as flexors of PIPJ (not extensors)
- Also hyperextend DIPJ
Psoriatic arthropathy
- Psoriasis = red, flaky partches of skin covered in silvery scales on elbows, knees, scalp and lower back (can be anywhere).
- 1-2% of population have Psoriasis
- Arthrits as a result of psoriasis = asymetrical oligoarthrits (one joint at a time, asymetrically)
- Most commonly affects small joints of hands and feet
- Fusiform (sausage shaped) swelling of digits = Dactylitis (Swollen digits)
- Joints stiffen
- Can progress to widespread joint destruction - arthrits mutilans
- Most commonly affect the DIPJs.
- 80% patients also have nail lesions - potting and onycholyosis (separation of nail from nail bed)
Osteoarthritis of 1st CMC joint and PIPJs, including Heberden’s nodes
- 1st Carpometacarpal joint is most commonly affected by osteoarthrits (between trapezium and 1st metacarpal)
- More common in women
- Pain at base of thumb
- Exacerbated by movement and relieved by rest
- Stiffness increases following rest (e.g mornings)
- Swelling around base of the thumb
- Later - 1st metacarpal subluxes in an ulnar direction - loss of normal hand contour
- Most common in 50s and 60s
- Gradual onset of pain in DIPJs
- Stiffness, reduced range of movement. swelling
Heberden’s nodes
- Classic sign of osteoarthrits affeting DIPJs of fingers
- Develop in middle age
- More common in women
- Run in families
- Begin with chronic sweeling of joint or sudden onset of pian, swelling and loss of manual dexterity.
- Initially, cystic swelling containing gelatinous hyaluronic acid on dorsal aspect of DIPJs.
- Inflammation and pain eventually subside and left with osteophyte
If in PIPJs = Bouchard’s Nodes
Carpel Tunnel Syndrome
- Compression of the median nerve as passes through the carpal tunnel from forearm into hand
- Most common site of nerve entrapment in the body
- May resut in: Ischaemia, focal demyelination, decrease axonal calibre (smaller area) and eventually axonal loss.
- Parasthesia in distribution of median nerve - worse at night as wrist drifts into flexion and compresses carpal tunnel further - results in waking up
- As worsens, daily activities (driving, combing hair, holding phone / book) can aggrevate it
- Sensation to palm spared - palmar cutaneous branch of median nerve pases proximal to the carpal tunnel and passes superficial into the palm so isn’t compressed.
- Long standing - muscle weakness and atrophy of thenar muscles.
- Can still flex and adduct the thumb
- Manual dexterity diministed
- Pain can occur proximallu in the forearm, elbow, shoulder and neck in into 1/3 patients.
Ulnar nerve compression in Guyon’s Canal
- Ulnar nerve compressed in Guyons canal as it passe radial (lateral) to the pisiform bone over the volar surface of the flexor retinaculum.
- Known as ulnar tunnel syndrome / Guyon’s canal syndrome / Handlebar palsy
- Parasthesia in ring and little fingers
- Progresses to weakness of intrinsic muscles of hand supplied by Ulnar nerve.
Dupuytren’s Contracture
- Localised thickening and contracture of the palmar aponeurosis leading to a flecion deformity of the adjacent fingers.
- Initially - thickening or ‘nodule’ in the palm
- Later - myofibroblasts within the nodule contract leading to formation of cords in the palmar fascia
- Overlying skin is tightly adherent to the palmar aponeurosis and becomes involved in the disease - also progresses to involve proximal fascia and skin of fingers.
- Finger become stuck in a flexed position “fixed flexion” and cannot passively be straightened
- Ring and little finger are most commonly affected - first webspace of thumb may also be involved
- 40-60 yrs old is not common
- More common in males and in northern european origin
- 70% cases = family history of condition (autosomal dominant)
- Other 30% are sporadic.
If a patient has an injury to the radial nerve in the spinal groove of the humerus, in what position will the patients wrist and fingers be when the wrist is pronated? Why?
The wrist and fingers will be flexed.
Injury of the nerve in the radial groove will result in paralysis of brachioradialis and all extensor muscles of the wrist and fingers.
This injury results in a wrist drop (inability to actively extend the wrist) and inability to actively extend the fingers,
The wrist and fingers are flexed when the forearm is pronated because of unopposed flexor muscles and gravity.
If a patient has an injury to the radial nerve in the spinal groove of the humerus, what is the likely distribution of sensory impairment?
The posterior cutaneous nerve of the arm branches from the radial nerve above the spiral groove so it unaffected.
The posterior cutaneuous nerve of the forearm branches in the spiral groove and is also usually unaffected, The parasthesia is therefore usually in the distribution of the superficial branch of the radial nerve.
If you had a supracondylar fracture of the humerus and damaged the median nerve, What position would the hand and forearm be in normally? When asked to make a fist?
The forearm will be supinated and in long standing lesions, an ape hand deformity may develop at rest.
Trying to make a fist is known as Hand of Benediction. This is not present at rest.
When the patient attempts to make a fist, the ring and little fingers will flex into the palm normally as FDP and lumbricals are still intact to these digits. However, the middle and index fingers will remain fully extended.
IPJs and MCPJs of the thumb will be extended (due to unopposed action of the EPL) and thumb will be abducted (due to unopposed action of adductor pollicis). Lateral rotation of the thumb occurs due to loss of oppenens pllicis (which usually medially rotates the thumb). In ling standing lesions, there will be wasting of the thenar eminence.
If an ulnar nerve injury to the wrist occurs why does the the patient make an ulnar claw?
The MCPJs of the ring and little fingers are hyperextended and the IPJs are flexed.
- 3rd and 4th lumbricals (acting on ring and little finger) are supplied by the ulnar nerve and hence paralysed.
- The lumbricals muscles flex the digts at the MCPJs and extend the digits at the IPJs via the dorsal expansion.
- In ‘ulnar claw’ MCPJs are hyperextended due to unopposed extension from extensor digitorum in the posterior compartment of the forearm.
- The proximal and distal joints are flexed due to upopposed flexion from the long flexor muscles (FDS and FDP) in the anterior compartment of the arm.
- The extensor muscles (extensor digitorum) cannot extend the IP joints as their energy is dissapated in hyperextending the MCPJs
