Hand Surgery Flashcards
What is a Bennett’s fracture?
A fracture-dislocation of the base of the thumb metacarpal.
Common injury (fall or punch)
How would a Bennett’s fracture appear on X-ray and why?
- Characteristic intra-articular fragment remains attached to the Beak ligament (anterior oblique ligament) ➞ results in metacarpal fragment articulating with Trapezium
- Metacarpal displaced proximally due to pull of AbPL
How is a Bennett’s fracture treated?
- Reduce the metacarpal back to the fragment
- Hold reduction with K wires or small screw
What is Rolando’s fracture
Comminuted fracture of the base of the thumb metacarpal (NOT dislocated)
How is a Rolando’s fracture treated?
Thumb splint
The Scaphoid is a bean shaped bone which is almost entirely covered in _______.
It articulates with the _______, _______ and _______ and can be palpated in the _______.
It has an unusual blood supply from _______ to _______ which comes from a branch of the _______ artery.
articular cartilage
distal radius, lunate, trapezium, anatomical snuffbox
distal, proximal, radial
Most common mechanism of injury of scaphoid fractures?
FOOSH injury
Initial investigation for a suspected scaphoid fracture?
Scaphoid series of X-rays (4 views)
What are the 4 scaphoid X-ray views?
- PA
- lateral
- oblique
- Ziter view (PA with wrist in ulnar deviation and beam angulated at 20º)
What is the definitive investigation for a scaphoid fracture?
MRI
Should be first-line imaging - but this is not common practice in the UK. It is commonly used second-line when X-rays are inconclusive
What is the biggest danger of a scaphoid fracture?
AVN ➞ occurs in the PROXIMAL POLE of the scaphoid
*chance of AVN increases with degree of displacement of fracture
How would a scaphoid fracture present?
- Pain in the anatomical snuffbox
- Pain along the radial aspect of the wrist, at the base of the thumb
- Loss of grip / pinch strength
What is a major differential diagnosis of distal radius fracture?
Scaphoid Fracture
List the the 4 Scaphoid provocation tests
What do these tell us?
- Snuffbox tenderness
- Pain on telescoping thumb metacarpal
- Pain on telescoping index metacarpal
- Pain on radial deviation of wrist and palpating distal pole of scaphoid (ulna dev???)
Greater number of positive = more likely fracture
How would you manage the following:
- Possible scaphoid fracture
- Undisplaced scaphoid fracture
- Displaced or proximal scaphoid fracture
- Immobilise and re-XR 7-10 days
- Immobilise in scaphoid cast or splint for 8 weeks
- Internal fixation
Position of wrist cast for a scaphoid fracture?
Wrist should be placed in the ‘beer glass position’
List 4 complications of a scaphoid fracture
- AVN
- Non union
- Post traumatic OA
- SNAC wrist (Scaphoid Non-union Articular Collapse)
What forms the roof and base of the carpal tunnel?
Roof: Flexor Retinaculum
Base and sides: Carpal Arch
List all structures passing through the carpal tunnel
Median nerve + 9 tendons
- tendon of flexor pollicis longus
- 4 tendons of FDP
- 4 tendons of FDS
List 3 symptoms of CTS?
- Tingling/pain in the first three digits
- Worse at night
- Relieved by shaking/ hanging out the hand at night
List 2 clinical signs of carpal tunnel syndrome
Paraesthesiae in distribution of median nerve ➞ radial 3 and a 1⁄2 digits
Thenar wasting in late disease
What additional muscle wasting may be seen In late carpal tunnel syndrome and why?
Abductor Pollicis Brevis as it is located in the Thenar Eminence and is innervated by median nerve
Is Thenar eminence sensation lost in carpal tunnel syndrome? Explain your answer
No, it is PRESERVED
This because the palmar cutaneous branch of median nerve does NOT pass through carpal tunnel
Differential diagnosis for carpal tunnel syndrome?
cervical nerve entrapment (eg C6 or C7 distribution)
What 2 tests aid diagnosis of carpal tunnel syndrome
Tinel’s test: tapping median nerve at level of volar wrist crease.
Phalen’s test: flexion of the wrist to 90 degrees and compression of the median nerve for 1 minute
List 4 risk factors for CTS
- Diabetes
- Pregnancy
- Hypothyroidism
- Acromegaly
- Radial fracture
- RA
Investigation of choice to diagnose CTS
Explain findings
Nerve conduction studies
Characteristic drop in conductance at level of CT ➞ helps differentiate from higher lesion (eg C6)
Management of carpal tunnel syndrome (in order)
- Rest and altered activities
- Wrist splints, can be worn at night
- Steroid injections
- Surgery decompression
Explain how a Carpal tunnel decompression is done
- Day case under local anaesthetic
- Can be open (vertical incision at wrist) or endoscopic surgery.
- Flexor retinaculum is cut to release pressure on the median nerve
What questionnaire can be used to predict liklihood of CTS?
The Kamath and Stothard carpal tunnel questionnaire (CTQ)
What is ‘Fight bite’
How does it commonly occur?
Extensor tendon rupture
- Usually due to a punch injury
- Orthopaedic emergency
- The tooth penetrates skin at the MCPJ
Management of ‘Fite Bite’?
- Open surgical washout of MCPJ, to prevent septic arthritis
- Primary tendon repair and splintage
- 5 days course of augmentin
Mechanism of a Flexor Tendon Rupture
Which tendon is usually affected?
Sudden resisted flexion of finger Eg. gripping a fast moving rugby jersey.
Classically affects FDP on middle finger
How does a flexor tendon rupture present?
- Distal volar tenderness and bruising
- Sensation of a mass proximal to the DIPJ
- loss of normal finger cascade
- Can flex PIPJ when all other fingers immobilised (FDS) but cannot flex DIPJ when PIPJ immobilised
- Inability to make fist/flex finger
Management of a Flexor Tendon Rupture?
Surgical (open repair with suture), followed by prolonged hand therapy and dynamic splinting
What is Rheumatoid drop finger?
Extensor tendon attrition rupture (at level of the ulnar styloid)
Seen in severe RA patients, as the tendon is degenerate due to synovial damage
How does Rheumatoid drop finger present?
- Sudden inability to extend one, or more, fingers
- Starts with little finger, then ring, then middle etc…
- Clinically cannot extend the digit on demand
Management of Rheumatoid drop finger?
Surgery
Describe the central slip anatomy of the extensor mechanism
Extensor tendon at level of the PIPJ divides into 3 ➞ 2 lateral bands, 1 central slip
The central slip extends the PIPJ and the lateral bands bypass to extend the DIPJ
Mechanism of a central slip rupture?
How does it present?
Sudden stubbing injury of finger causes rupture of central tendon at PIPJ
Presents as:
- Pain over the dorsum of PIPJ
- Swelling and tenderness
- Can actively extend DIPJ, but struggles to extend PIPJ in isolation
If a central slip rupture is missed what is the patient at risk of developing?
Describe this deformity
‘Boutonniere’ deformity
Fexed PIPJ and hyperextended DIPJ
How do we treat a Boutonniere deformity?
- Splinting in extension
- Surgical repair
What is Mallet finger?
What is the characteristic finding?
Avulsion of the extensor tendon insertion into the base of the distal phalanx
Characteristic extensor lag of DIPJ
What are the 2 types of Mallet finger?
Bony or non-bony mallet
- Bony mallet = flake fracture attached to tendon end
- Non bony mallet = simple tendon avulsion from distal phalanx, no fracture
How do we treat Mallet finger?
List a common long term effect?
Immobilisation in a mallet splint for 8 weeks
Long term stiff DIPJ
What is Dupuytren’s Contracture?
Contracture of the palmer fascia resulting in a fixed flexion deformity of one or more digits
List 4 risk factors for Dupuytren’s
- Age
- Family history (autosomal dominant pattern)
- Male
- Manual labour, particularly with vibrating tools
- Diabetes (more with type 1, but also type 2)
- Epilepsy
- Smoking and alcohol
Pathophysiology of Dupuytren’s?
Caused by proliferation of myofibroblasts in the palmar fascia.
Results in a progressive deformity with time
Medication and condition associated with Dupuytren’s?
Epileptic medication and alcoholism
Which finger is most often affected in Dupuytren’s?
The ring finger
How does Dupuytren’s present?
Painful palmar nodules and/or knuckle pads over dorsum of MCPJs
Ectopic presentation ie. on feet (aka Ledderhose disease) - this is rare
What test can help identify Dupuytren’s?
The table-top test
Patient tries to position their hands flat on a table, positive if they cannot
When should surgery be considered for Dupuytren’s contracture?
When the MCP joints cannot be straightened and thus the hand cannot be placed flat on the table
Surgical treatments for Dupuytren’s Contracture?
- Needle fasciotomy
- Limited fasciectomy
- Dermofasciectomy
What is Skier’s thumb? (Gamekeeper’s thumb)
Thumb Ulnar collateral ligament rupture due to forced abduction injury of thumb MCPJ
Most commonly seen after fall when skiing with pole still in hand
Treatment for Skier’s thumb? (stable/unstable/fracture).
Clinically stable on forced abduction ➞ Thumb splint
Clinically unstable ➞ USS to look for Stener lesion. If present then Surgical repair
If fractured, displaced and unstable ➞ ORIF
What is a Stener lesion?
When the UCL tears, folds back on itself and gets stuck behind the abductor pollicies brevis tendon
60% of UCL ruptures
