Hand deformities Flashcards
Intrinsic minus Intrinsic plus Boutonniere Swann neck Mallet finger Jersey finger Quadrigia effect Lumbrical plus
What is a Intrinsic minus hand?
- Imbalance between STRONG EXTRINSICS and weak INTRINSICS
What is Intrinsic minus hand characterised by?
- MCP Hyperextension
- PIPJ and DIPJ FLEXION
Describe the Aetiology of Intrinisic minus hand?
-
Ulna Nerve Palsy
- Cubital tunnel syndrome
- Ulnar tunnel syndrome
-
Median Nerve Palsy
- Volkmann’s iscahemic contracture
- Leprosy ( Hansen’s disease)
- Failure to splint hand in intrinsic plus hand after crush injury
- Charcot Marie Tooth ( hereditaty motor-sensory neuropathy)
- Compartment syndrome of the hand
Can you describe the pathoanatomy of intrinsic minus hand?
- Loss of intrinsics-> loss of baseline MCP flexion/ IP extension
-
Strong extrinsics= EDC
- unopposed action-> MCPJ extension
-
Strong FDS/FDP
- unopposed action->PIPJ/DIPJ flexion
What are the signs and symptoms of a intrinisc minus hand?
Symptoms
Decreased hand funciton
Signs
- MCPJ hyperextension, DIPJ/PIPJ Flexion
- in ulna nerve palsy 4/5 digits worse> than 2/3 ( lumbrical innervated by median nerve)
- Functional weakness- reduced grip/pinch strength
- unable to do prehensile grasp
Provocative test
If MCPJ taken out of extension-> flexion at DIPJ/PIPJ will correct
What is the tx of Intrinsic Minus hand?
Operative
- Contracture release & Passive tenodesis
- Active tendon transfer
- in pts that progressive deformity effecting life
- Goal is to prevent MCPJ hyperextension
What is an intrinisic plus hand?
Caused by muscle imblance between
- SPASTIC Intrinsics- Interosseoi and lumbricals
- Weak extrinsics- FDP/FDS/EDC
What are the characteristics of an intrinsic plus hand?
- MCP flexion
- DIPJ/PIPJ Extension
What is the aetiology of an intrinsic plus hand?
- Trauma- direct/indirect
- Vascular injury
- compartment syndrome
- RA- mcpj dislocations & ulna deviation->spastic intrinsics
-
neurologic
- traumatic brain injury
- cerebral palsy
- CVA
- Parkinson’s
What is the pathoanatomy of intrinsic plus?
- Spastic intrinsics->flexion MCPJ, extension IPJ
- EDC Weakness->fails to provide balancing forces
- FDP/FDS weakness->f_ail to provide balancing forces_
What are the signs and symptoms of intrinsic plus hand?
Symptoms
Difficulty gripping large objects- see pic
Signs
MCPJ flexion, IPJ extension
BUNNELL test- intrinsic tightness test-
1) With the MCPJ in extension the intrinsics are put on a stretch. Try to flex the PIPJ with MCPJ in extension. If it doesn’t flex = tight intrinsics or joint capsule contracture.
2) With MCPJ in flexion the intrinsics are relaxed. Thus if unable to flex PIPJ= tight capsule.
NB- prior to test check that passive motion of PIPJ is possible (i.e. normal PIPJ)
**so pt will not be able to flex PIPJ/DIPJ when mcp is extended cf flexed if intrinsics are tight
What are the tx of intrinsic plus hand?
Non operative
Passive stretching- mild cases
Operative
-
Proximal muscle slide- where some func of intrinsics remains- spastic
- Subperiosteal elevation of interossei lengthn muscle-tendon unit
-
Distal intrinsic release- distal to MP for more severe deformity involving MCP/IPJ
- Resection of intrinsic tendon distal to transverse fibres responsible for MCPJ flexion
What is Boutonniere Deformity?
- Zone 3 extensor tendon Injury characterised by
- PIPJ Flexion
- DIPJ extension
What is the aetiology of Boutonniere Deformity?
-
Rupture of the Central Slip by
- laceration
- traumatic avulsion
- capsulat distension- RA
Describe the pathoanatomy of Boutonniere Deformity?
- Rupture of central slip- loss of EDC extensor mechanism
- Attenuation of Triangular ligament ( N prevents lat bands slip volar)-> Lumbricals ( intrinsics) act like flexors at PIPJ, as unopposed at DIPJ lumbricals-> extend DIPJ
- Palmar pull of collaterals and lumbricals. l_umbricals pull unopposed, pull thru base of distal phalanx and volar to pip_j-> PIPJ flexion/DIPJ extensio