Differential Diagnosis of Musculoskeletal Disorders
Abnormal Foot Positions
- FOREFOOT
- Varus = adduction
= axis of 1st metatarsal deviated medially relative to axis of talus - Valgus = abduction
= axis of 1st metatarsal deviated laterally relative to axis of talus - Inversion = supination
= inward turning of sole of foot - Eversion = pronation
= outward turning of sole of foot - HINDFOOT
talipes = any deformity of the ankle and hindfoot
[talus, Latin = ankle; pes, Latin = foot]
- Equinus
= hindfoot abnormality with reversal of calcaneal pitch so that the heel cannot touch the ground - Calcaneal foot
= very high calcaneal pitch so that forefoot cannot touch the ground - Pes planus = flatfoot
= low calcaneal pitch + (usually) heel valgus + forefoot eversion - Pes cavus
= high calcaneal pitch (fixed high arch)
Clubfoot = Talipes Equinovarus
Common severe congenital deformity characterized by
- equinus of heel (reversed calcaneal pitch)
- heel varus (talocalcaneal angle of almost zero on AP view with both bones parallel to each other)
- metatarsus adductus (axis of 1st metatarsal deviated medially relative to axis of talus)
- Arthrogryposis multiplex congenita
- Chondrodysplasia punctata
- Neurofibromatosis
- Spina bifida
- Myelomeningocele
Rocker-bottom Foot = Vertical Talus
- vertically oriented talus with increased talocalcaneal angle on lateral view
- dorsal navicular dislocation at talonavicular joint
- heel equinus
- rigid deformity
Associated with: Arthrogryposis multiplex congenita; spina bifida; trisomy 1318
Talar Beak = Hypertrophied Talar Ridge
- Talocalcaneal type of tarsal coalition
- Diffuse idiopathic skeletal hyperostosis (DISH)
- Acromegaly
- Rheumatoid arthritis
Heel Pad Thickening
= heel pad thickening >25 mm (normal <21 mm)
mnemonic: MAD COP
- Myxedema
- Acromegaly
- Dilantin therapy
- Callus
- Obesity
- Peripheral edema
Soft-tissue Masses of Foot + Ankle
- NONTUMORAL
- synovial proliferations
- Pigmented villonodular synovitis (PVNS)
- Giant cell tumor (GCT) of tendon sheath
- posttraumatic
- Plantar fasciitis
- inflammatory
- uncertain origin
- Ganglion cyst
- Epidermoid cyst
- Morton neuroma
- Florid reactive periostitis
- Rheumatoid nodules
- BENIGN TUMORS
- Plantar fibromatosis
- Deep fibromatosis
- Infantile digital fibromatosis
- Hemangioma
- Nerve sheath tumor
- Lipoma, angiolipoma
Outline