Foot And Ankle Flashcards
What are the histological findings in a Morton’s neuroma?
Perineural fibrosis
Endoneural thickening
Degeneration of nerve fibres
No true neuroma
What are the contents of the tarsal tunnel?
Tibialis posterior tendon FDL Posterior Tibial artery & vein Tibial nerve FHL
Flexor retinaculum (laciniate ligament) proximally Fascia of Abductor Hallucia distally
What are the terminal branches of the posterior tibial nerve?
Medial plantar
Lateral plantar
Medial calcaneal
Branch in tarsal tunnel
Distal TTS is compression of 1st branch of lateral plantar nerve
What are the causes of tarsal tunnel syndrome?
Trauma - soft tissue and osteous
SOL - ganglion, lipoma, neurilemmoma, varicose vein, anomalous muscle - per quart
Biomechanical malalignment of ankle /foot
Tenosynovitis Tib Post, FHL, FDL
Who affected more frequently with CMT - male or female?
Male more common
Female more severe
What re the major characteristics of Charcot Marie Tooth?
Foot deformities - Cavovarus foot
DDH
Hand weakness - intrinsics
Scoliosis
4 causes of a Cavovarus foot
Residual clubfoot
Idiopathic
Neurolomuscular - CMT,
Traumatic - compartment syndrome, TA rupture
Unilateral - Neuro, trauma, reisdual
Bilateral - CMT
Neural pathology & genetics of CMT
Motor Nerve root degeneration
CMT1 - Myelin sheath
CMT 2 - Axonal
CMT1A - 70% have PMP22 gene duplication Chromosome 17 (peripheral myelin protein 22)
X-linked - Schwann cells. Connnexin 32 gene mutation
Makes moderately affected. Females no symptoms.
Recessive - early onset and more rapidly progressive
Inheritance pattern of CMT
1 AD 50%
2 AD 20-40%
X-linked 10-20%
3&4 AR rare
CMT 3 Dejuerine-Sottas disease
Add spasticity versus falcid in type 1 /2
Radiographic angles for the Cavovarus deformity of CMT
LATERAL
Meary’s angle - long axis talus and 1st MT - 0-10•
Hibb’s angle - long axis Calc and 1st MT -
Differential diagnosis for SPN compression neuropathy
Lateral ankle sprain - not healing Chronic compartment syndrome Fascial defects Muscle herniations Proximal nerve entrapments - similar to L5
Name the AVN conditions of the foot?
Kohler’s - Navicular in kids 2-9. Muller-Weiss in adults
Freiburgs - 2nd MT. Smilie classification 1-5. MRI to just dorsal collapse to OA
OT - cheilectomy, dorsal wedge closing, Duvries Arthroplasty
Incidence of Charcot in diabetics?
Time to conte lateral foot involvement?
- 1-1.5% of all diabetics
- 5% in those with a peripheral neuropathy
10-35% have bilateral disease
Average time to second foot is 2 years - usually staged not simultaneous
What is the duration of onset of Charcot in diabetics by type?
Type 1 - present younger (5th decade) but later ie 20-25 years after diagnosis
Type 2 - present older (6th decade) but earlier ie 5-10 years after diagnosis
What are the 6 X-ray findings in Charcot?
Disorganisation Destruction Debris Disuse osteopaenia Dislocation Distension of soft tissues
The 6 Ds
7 pathoanatomic components of hallux valgus
Lateral deviation Great toe Medial deviation MT Bunion Pronation great toe Hallux valgus interphalangeus Lesser toe deformities Metatarsalgia
What are the DDs for heel pain?
17 in JAAOS book
Plantar fasciitis Plantar fascia rupture Fat pad atrophy Fat pad contusion Calcaneal stress fracture Baxter's nerve entrapment - 1st branch LPN, between ABd Hallucis and QP Severs disease Tumour - OO, chondroblastoma Tarsal tunnel syndrome Gout Inflamm arthropathies Spondyloarthropathies Infection Pagets Neuropathy Radiculopathy Foreign body reactions
OCD lesions - where, trauma?
Medial are posterior, larger and deeper
Lateral are anterior, more related to trauma and resistant to non-op management
Stage Tib post dysfuntion
1 - No deformity - Tenosynovectomy
2a - Mild / mod flexible with minimal abduction - 30% - Lat column length or hindfott fusion
3 - Fixed - Hindfoot fusion
4 - Foot and ankle deformity - Complete correction of foot, possible deltoid recon. Severe arthritis - ankle fusion or arthroplasty
4a - Ankle deformity and Flexible foot - Correct foot as per 2b
4b - Ankle deformity and a fixed foot - Correct foot as per stage 3
