Ankle/foot - MSK Flashcards
Ankle sprains
-Ligamentous injury
-Usually inversion mechanism
->90%: lateral ligaments: 90% ant. talo-fibular, <5% tib-fib syndesmosis
-Lateral ligaments tear in sequence, anterior to posterior
-Deltoid ligament sprain: Due to eversion mechanism, Usually with associated fibula fx.
-Pain, swelling
-+/- inability to bear weight
-Foot may be inverted (talar tilt)
-Passive inversion increased pain
-Stress maneuvers: Drawer test, Inversion stress
-X-ray: Normal
-Ottawa Ankle Rules: X-ray only required if:
Bony tenderness along distal 6 cm. of tibia or fibula, Bony tenderness at base of 5th metatarsal or Inability to bear weight, both immediately after injury and in emergency department
Tx:Ice, elevation
-Immobilize with plastic or plaster splint
-Consider crutches If moderate to severe or If difficulty bearing weight with splint
-Third degree sprains may need surgery (rare)
Chronic lateral ankle instability
-Chronic ligamentous instability after ankle sprain (10-20% of sprains)
-Sx: recurrent pain/swelling, ankle feels “unsteady”, recurrent sprains with minimal mechanism
-Exam: talar tilt, laxity with inversion stress
Treatment: Ankle brace
Surgical: ligamentous repair
Ankle fractures
- May be malleolar, bimalleolar, trimalleolar
- Often disrupt tib-fib ligament, and thus, disrupt mortise joint
- Tib-fib (syndesmotic) ligament normally maintains integrity of mortise
- Exception: distal fibula fx.
- Pain, swelling, bruising, inability to bear weight
- Significant deformity if dislocation present as well
- Reduce fracture-dislocations
- Immobilize in splint, Elevate
- Surgery needed if mortise disrupted
- Need to restore anatomic position of talus on mortise
- Ensure smooth articular surface
- Cast 6-8 weeks
- Arthritis likely if poorly aligned joint surface
Calcaneus Fx
- Most commonly fractured tarsal bone
- Mechanism usually due to compression
- e.g., fall from height
- 10% associated with lumbar fx.
- 26% associated with other extremity injury
- Clinical: Swelling, pain, ecchymosis
- X-ray: Standard foot films usually demonstrate, Consider calcaneal views
- Treatment: Surgical, need to restore anatomy
Talar fracture
- Usually due to foot hyper-plantar flexion
- Fx. may involve dome, neck or body
- Talus covered by cartilage, blood supply tenuous: Fx. may lead to avascular necrosis
- Intense pain
- Inability to bear weight
- Localized tenderness and swelling
- May have loss of normal foot contour
- Caution “ankle sprain” misdx.
- Dx. with foot x-rays
- Ice, elevation, immobilization
- Nonsurgical, if non-displaced minor chip fx. of dome
- Surgery, if displaced fx. of neck or body
Midfoot: Cuboid fracture
- Usually due to crush injury
- Usually associated navicular or cuneiform injuries
- Pain/swelling/ tenderness
- Foot x-ray
- Conservative rx., if non-displaced
- ORIF, if displaced
Midfoot: Proximal 5th Metatarsal Fx.
- By far, the most common metatarsal fx.
- Often occurs with lateral ankle sprain
- Always check for tenderness at base of 5th MT when evaluating ankle sprain
- Ankle x-rays must visualize this area
- Usually due to inversion/avulsion of prox. bone by peroneus brevis tendon
- Treatment: Usually conservative, Immobilize, Crutches
Jones Fracture of 5th Metatarsal
- Not an avulsion fx.
- Involves diaphysis of 5th metatrasal
- Has higher incidence of non-union or delayed union
Forefoot fractures: stress fx
- Stress fractures of midshaft metatarsals
- Usually, 2nd and 3rd MT’s, which are relatively fixed
- 1st, 4th and 5th relatively mobile
- Due to excessive stress over time
- May not appear on x-ray for 2-3 wks.
- If suspected: Bone scan, Repeat xray in 2-3 wks.
- Tx: rest, possibly immobilize
Forefoot fractures: complete
- Complete midshaft metatarsal
- Usually crush mechanism
- Occasionally due to twisting mechanism
- Often more than one MT is fractured
- Rx: ice, immobilize with plaster/fiberglass
Forefoot fractures
- Phalanges (toes)
- Common; often see fracture-dislocation
- Usually due to direct trauma or hyper-extension
- Exam: pain/swelling, deformity if dislocated
Tx:
- reduce fx and/or dislocation
- Immobize with dynamic splinting (“buddy taping”)
- Stiff-soled shoes
- Great toe bears 1/3 of weight of body on that side: may require walking cast
- If unable to reduce, may require internal fixation (rare)
Metatarsalgia
- Nagging forefoot pain over middle metatarsal heads
- Usually due to faulty weight distribution
- e.g., weight gain, hallux valgus, flat foot
- Transverse arch becomes depressed
- Metatarsal heads bear disproportionate weight
- Also: gout, rheum. arthritis
- Treatment
- Symptomatic
- Directed at cause
Morton’s neuroma
-A neuropathy of interdigital nerve, usually proximal to bifurcation
-Usually nerve supplying 2nd & 3rd toes
-Nonspecific inflammation of nerve with proliferative connective tissue
-Usually middle-aged women
-Usually unilateral
-Sudden attacks of sharp or burning pain, radiating to toes
-At first, pain only with walking
-Later, pain even at rest
-Localized webspace tenderness, reproduces pain
-May palpate small mass in webspace
Management: Initial: steroid/lidocaine injection, Definitive: surgical excision
Hallux Rigidus
- Stiffness of MTP joint of great toe
- Caused by arthritis, local trauma, gout
- More common in men
- Pain with walking
- Tender MTP joint, pain with dorsiflexion
- X-ray: Arthritic changes: osteophytes, narrowed joint space
- Management: Rocker-soled shoes, NSAIDs, possibly surgery (joint replacement vs. fusion)
Hallux Valgus
-The most common foot deformity
-Great toe angles “inward” (valgus)
-More common in females
-Often familial
-Obvious deformity
-Prominent bunion
-Red, swollen
Management
-Conservative: Wide, padded shoes
-Surgical: Corrctive osteotomy
