20 - Hand and Wrist Conditions Flashcards
What bone in the hand is the most likely to fracture and what is the common mechanism of injury?
- Scaphoid (10% hand fractures and 80% carpal fractures)
- FOOSH (hyperextension and impaction of bone on radius or axial end on compression)
- Mainly young adults and adolescents
What are the clinical features of a scaphoid fractures?
- Pain in anatomical snuffbox and exacerbated by moving the wrist
- Passive range of motion reduced but not dramatically
- Swelling around the radial and posterior wrist
- Fractures mainly at the waist, sometimes proximal or distal (scaphoid tubercle)
How should you investigate a scaphoid fracture?
- Plain X-ray may not the fracture initially
- Follow up x-ray 10-14 days later and the fracture line may be visible due to bone resorption. In the meantime if fracture suspected treat as fracture
- After 10-14 days if still not clear but still symptomatic can use MRI or CT
What is the complication of a scaphoid fracture?
- Retrograde blood supply and weak supply to proximal scaphoid
- Displaced fractures: risk of non-union, malunion, avascular necrosis, secondary OA, carpal instability
- OA more common if non-union, malunion and AVN
What is a Colles’ fracture and what will it present like?
- Extraarticular fracture of the distal radial metaphysis with dorsal angulation and impaction
- Ulnar styloid fracture in 50% cases
- Can be viewed on lateral x-ray and patient will have painful deformed swollen wrist
What is the difference between a Colle’s and Smith’s fracture?
What is the mechanism of injury of a Colle’s fracture and who is affected the most?
- FOOSH with pronated forarem and wrist in dorsiflextion
- Patients with osteoporosis so post menopausal women
- Often in high impact trauma like skiing
- Dorsally angulated and impacted
How is a Colle’s fracture treated and what are the complications?
- Reduction and immobilisation in cast
- Malunion leading to dinner fork deformity
- Median nerve palsy and post traumatic carpal tunnel syndrome
- Secondary OA (more common when intra-articular)
- Tear of EPL due to tendon over sharp bone fragment
What is a Smith fracture?
Fracture of distal radius with volar angulation of distal fracture fragment(s). Mainly extra articular
What is the mechanism of a Smith’s fracture and what are the complications?
- Young males and elderly females
- Fall onto flexed wrist or direct blow to back of wrist
- Garden spade deformity which is cosmetically unattractive and can distort carpal tunnel so carpal tunnel syndrome
What is a quick overview of rheumatoid arthritis?
Autoimmune disease where autoantibodies, rheumatoid factor, attack synovial membrane. The inflammed synovial cells proliferate to form a pannus which penetrates cartilage and bone leading to erosion and deformity. Mainly affects MCPJ and PIPJ of hands and feet and cervical spine
What might a patient with Rheumatoid arthritis present with and why is it difficult to diagnose?
- Picture is initial presentation
- Late presentation: nodules, x-ray feautures, hand deformities
- Hard to diagnose as it is bilateral swelling so no normal to compare it to
What are the x-ray features of rheumatoid arthritis?
What are the deformities of the finger joints in rheumatoid arthritis?
- Swan Neck
- Boutonneire
What is swan neck deformity due to?
- PIPJ hyperextended, DIPJ and MCPJ flexed
- Tissues on palmar aspet of PIPJ become lax due to adjacent synovitis so imbalance of muscle forces (extension > flexion) so joint with lax tissues is hyperextended
- DIPJ there is elongation or rupture of ED on base of proximal phalanx so mallet deformity
What is Boutonniere deformity?
MCPJ and DIPJ hyperextended and PIPJ is flexed
- Inflammation in PIPJ causes lengthening of central slip of ED at it’s insertion on base of middle phalanx on dorsal surface of finger. Lateral bands slip down sides of fingers so they are on palmar surface and act on PIPJ as flexors for PIPJ and hyper extending DIPJ
What is psoriatic arthropathy and how does it present?
- Patient with psoriasis having arthritis
- Asymmetrical oligoarthritis and usually involves small joints of hands and feet, mainly DIPJ (not MCPJs and PIPJ like rheumatoid)
- Fusiform digit swelling (dactylitis) and the joints stiffen
- Arthritis mutilans so widespread destruction of joints
- Most patients have nail lesions like pitting or onycholysis
What joint in the hand is most commonly affected by OA and what does it present as?
- 1st CMCJ (trapezium and 1st MC)
- Mainly women complaining of pain at the base of their thumb, exacerbated by movement and relieved by rest. Stiffness after rest (morning) and swelling around base of thumb.
- Later subluxation of 1st MC in ulnar direction causes squaring of hand
In the following types of arthritis, what joints in the hand are mainly affected?
- Rheumatoid
- OA
- Psoriatic
- PIPJ, MCPJ
- 1st CMC and DIPJ
- DIPJ
When is OA of the fingers most common and what does it present as?
- 50/60 years old
- Gradual onset of pain in DIPJ
- Stifness, reduced range of movement and swelling
What is the pathophysiology of Herberden’s nodes?
- DIPJ joints
- Mainly middle aged women who have family historu
- Chronic swelling or sudden onset of pain, swelling and loss of manual dexterity
- Cystic swelling of gelatinous hyaluronic acid on dorsolateral aspect of joint then the pain and inflammation will subside and they are left with osteophyte*
What is carpal tunnel syndrome in general and what are the risk factors of this condition?
- Compression of the median nerve as it passes through the carpal tunnel into the forearm
- Risk factors: pregnancy, obesity, repetitive wrist work, rheumatoid arthritis, hypothyroidism
What happens when the median nerve is compressed on a cellular level?
- Ischaemia
- Focal demyelination
- Axonal loss
What does carpal tunnel syndrome present as and why?
- Paraesthesia in median nerve distribution (see image)
- Symptoms worse at night as wrist drifts into flexion narrowing tunnel so patient often wakes
- Activities like driving, combing hair, holding book or phone can aggravate paraesthesia
- Muscle weakness and atrophy in thenar eminence if long standing (still flex thumb as FPL and FPB innervated by ulnar and can adduct as AP innervated by ulnar)
- Diminished manual dexteritiy (e.g buttoning clothes)
- Pain can occur proximal forarm, elbow, shoulder, neck
Why is palmar sensation still in tact with carpal tunnel syndrome?
Palmar cutaneous branch branches proximal to carpal tunnel and passes superficial to it
(picture is thenar wasting secondary to carpal tunnel syndrome)
What does an ulnar nerve compression in the Guyon’s canal present as?
- Ulnar tunnel syndrome/Handlebar palsy as nerve passes radial to pisiform
- Paraesthesia in ring and little finger with progressive weakness of intrinsic muscles of hand supplied by ulnar nerve (mainly AP and interossei, also lumbricals to ring and little fingers and FPB but they aren’t noticed by patient)
What is Dupuytren’s contracture?
Localised thickening and contracture of the palmar aponeurosis leading to a flexion deformity of adjacent fingers
How does Dupuytren’s contracture progress?
- Initially thickening or nodule on palm that is painful or painless
- Later myofibroblasts in nodule contract to form cords in palmar aponeurosis and they also affect fascia and skin of finger
- Fingers stuck in flexed position and cannot be passively straightened
What are risk factors for Dupuytren’s contracture and who is most commonly affected?
- Most commonly affects ring and little finger
- Most commonly affects Northern European men 40-60 years old and have a family history of autosomal dominant
- Learn 5 risk factors from picture
What is dupuytren’s diathesis and what is the treatment?
- Young patient
- Family history
- Table top test cannot lay flat
- Collagenase injection or needle fasciotomy
