Deformities
Mallet
- DIP flexed
- MTP / PIPJ neutral
Hammer
- PIP flexion
- DIPJ neutral / extended
Simple - MTP not involved
Complex - MTP hyper-extended
Claw
- PIPJ and DIPJ flexed
- MTPJ hyperextended
Curly toe
- PIP and DIP flexion
Great toe
- only have hammer
- no mallet
Claw toe v hammer toe
1. Claw toes frequently are caused by neuromuscular diseases
- often a similar deformity is present in all toes
- in hammer toe deformity only one or two toes are involved
2. Claw toes always have extension deformity at the MTPJ
- in hammer toe deformity extension of metatarsophalangeal joint may or may not be present
3. Claw toes often have a flexion deformity at the distal interphalangeal joint
- this usually does not occur in hammer toes
Anatomy
EDL
- divides 3 slips over P1
- middle - P2
- sides - P3
- thus no insertion to P1
- but main action is to extend P1 at MCPJ
- only extends IPJ if P1 neutral or flexed
EDB
- arises upper and lateral surface of calcaneum
- has four tendons
- one inserts into base P1 great toe - EHB
- other 3 into lateral side of EDL tendon toes 2 - 4
FDL
- inserts P3
- flexes DIP
FDB
- inserts P2
- flexes PIP
Interossei
- dorsal to transverse ligament
- insert P1 (mostly) and extensor hood
- mainly MTPJ flexor
Lumbricals
- plantar to transverse ligament
- insert extensor hood only
- mainly allow IPJ extension with MTPJ flexion
Aetiology
Shoe Wear
- main cause is ill-fitting shoes
Hallux valgus
Trauma
- compartment syndrome
- fracture
- tendon or ligament injury
Anatomic
- long 2nd ray with buckling of toe
- irregularly shaped P2 with deviation of P3
- long 4th toe with curling under 3rd toe
Neuromuscular
- Polio
- CMT
- MD
Inflammatory arthritis
- RA
Congenital
- Syndactyly
- CMT
Insensate Foot
- DM
- Hansen's disease