Foot and Ankle Flashcards
ankle sprain vs fracture stats
- > 25K ankle sprains/day in US
- Inversion injuries are most common
- Sprain may also be associated with: peroneal tendon tear , subluxation, sprain of subtalar joint, fracture @ the base of the 5th metatarsal, avulsion fracture of the calcaneus or talus
ankle sprain vs fracture initial presentation
o Pain over injured ligaments
o Swelling or bruising
o Loss of function
o Patient may describe hearing a pop during the initial injury or a feeling of instability while ambulating.
ankle sprain vs fracture exam
Tenderness to palpation (TTP) over affected ligaments or bony areas if fracture occurred
- Always palpate proximally to r/o fracture of prox fibula or tibia and distally to r/o foot fracture
- Neurovascular exam to ensure intact
ankle sprain vs fracture diagnostics
X-ray- r/o fracture
- Can use Ottawa Ankle Rules to determine if x-rays are required
- 3 views of the ankle (lateral, anterior posterior (AP), oblique)
- Assess joint spaces for appropriate alignment (Mortise: where tibia and fibula articulate with talar dome)
ankle sprain vs fracture
o If no fracture visualized on X-ray, likely diagnosis is an ankle sprain
o Based on clinical findings you will have determined whether injury involves the lateral, medial or both sets of ankle ligaments
if pain is on lateral aspect of ankle
Classification of Lateral Ankle Sprains
- Grade I: Anterior talofibular ligament with no instability
- Grade II: Anterior talofibular ligament and calcaneofibular ligament with mild laxity of one or both ligaments.
- Grade III: injury and significant laxity of both anterior talofibular ligament and calcaneofibular ligament
Superficial Deltoid ligament: superficial deltoid lig primarily resists eversion of hindfoot;
which widens mortise and produces chronic ankle instability
if pain is on medial aspect of ankle
Danger! Review Xrays carefully
Clues that the joint may be unstable:
- May see small avulsion fracture of tibia where deltoid ligament attaches
- Oblique fracture of fibula may cause disruption of the deltoid ligament
- Look for lateral shifting of talus
- When found, refer to specialist for repair
o less than 4 mm o less than 4 mm o less than 4 mm o less than 4 mm o Less than 4mmm
in absence of a medial malleolar fracture deltoid ligament may be stretched or torn in all oblique frx of fibula;
medial ecchymosis appears after 24 hrs when the deltoid ligament has been disrupted)
ankle sprain treatment
o The goal is to prevent re-injury and allow tightening of ligaments to prevent chronic instability
Mild
- WBAT in ankle brace 3-4 weeks
- RICE
- NSAID’s
Severe
- Immobilization for 3-4 weeks: weight bearing as tolerated (WBAT) with crutches in controlled ankle motion boot (CAM boot) or non-weight bearing splint for those too painful.
- Rest, ice, NSAIDs
- At 3-4 weeks (usually 3) transition into ankle brace for 3 weeks and then wean out
- You can Rx physical therapy to start gentle ROM, then progress to strength and balance.
- Can take 8-12 weeks to heal.
ankle fracture
o Many different classifications of fracture patterns
o If joint is unstable, refer
o These will need referral: Maisonneuve Fracture: ankle fracture associated with fracture at proximal fibula, deltoid ligament tear and disruption of syndesmosis. Bimalleolar or trimalleolar fractures, Anything with widened mortise
o A ring usually breaks in two separate regions and this is often the case in the ankle joint. If there is a break in the tibia on the inner side, one has to look for a disruption somewhere between the fibula and the talus on the outer side. This may be a torn ligament which will not show on x-ray but is important none the less. The interosseous membrane between the tibia and the fibula must be considered an ankle ligament in this context. It is often torn in ankle injuries.
o The third malleolus is the back of the tibial joint surface which can be broken in some patterns of ankle fracture
ankle fracture treatment
Non operative
- Stable fracture
- NWB cast initially, change to weight bearing once evidence of healing bone on X-ray (typically 4-6 week range from initial DOI)
- Gradually increase weight bearing status and start Physical Therapy as needed
Operative
- Unstable fractures
- Typically ORIF (open reduction, internal fixation)
talus fractures
o Result from high energy trauma such as fall from height or MVA; consider compression fracture of lumbar spine in ddx
o Mechanism typically extreme forceful dorsiflexion
o Most common fracture site is the talar neck
o Tenuous blood supply so increased risk of avascular necrosis, worse with displacement
talus fractures exam
o Moderate ankle swelling and TTP over anterior ankle and often talar neck dorsally
o Possible varus/valgus deformity
o Assess neurovascular status
talus fractures diagnostics
o Begin with 3 view x-ray of ankle. Lateral, AP and oblique
o Consider CT of ankle if high suspicion and to characterize
Hawkins classification of talar neck fractures 1-4
o I-10% AVN, II- 40%, III-90%, IV – 100%
talus fractures treatment
All referred to orthopedic specialist
- Non-displaced treated non-operatively with serial x-rays. Still up to 10% chance of AVN
- Displaced treated with ORIF
midfoot (lisfranc) fracture/injury
- Traumatic disruption of the tarsometatarsal joints: fracture, dislocation or both
- Result from significant trauma or indirect mechanism (Originally described in soldiers whose horse fell on their foot)
- Critical injury to the 2nd tarsometatarsal joint (Stabilizing apex for other TMT joints as it “keys” into cuneiforms, Additionally no connective tissue holding 1st metatarsal to the 2nd metatarsal)
- However, there is no connective tissue holding the first metatarsal to the second metatarsal. A twisting fall can break or shift (dislocate) these bones out of place.
- Unrecognized Lisfranc injuries can have serious complications such as joint degeneration and compartment syndrome
- Falling forward over a plantar flexed foot like when missing a step on a staircase
- Often present as a “sprain” over dorsum of foot
- Mechanism is often axial loading verticle foot or torque to fixed foot
- Foot may be mild to moderately swollen, maximum tenderness/swelling over distal mid-foot
- Physical Exam: stabilize hindfoot and try to rotate forefoot (Positive = pain)
midfoot (lisfranc) fracture/injury diagnostics
o X-ray: standing AP, Lateral and Oblique of the foot. Stress/weight bearing views prn. (On AP: Medial aspect of 2nd MT should line up with medial aspect of middle cuneiform. Shift = Lisfranc injury, On oblique: Medial 4th MT should line up with medial cubiod surface. Shift = Lisfranc injury)
o If high degree of suspicion and x-ray unclear, MRI of foot should be obtained.
o Comparison views often helpful
o MRI or CT scan if no dx from xray
Midfoot (lisfranc) injuries treatment
Nondisplaced:
-8 weeks in NWB cast followed by use of rigid arch support for 3 months
Displaced >2mm:
- ORIF
- Remove fixation after 6 months with custom rigid orthotic for 6 additional months
- Can take up to 12 weeks to heal properly
o Adverse outcome when misdiagnosed or improperly treated: compartment syndrome, arthritis, instability
o ***When missed and delayed 6 weeks, ORIF no longer an option and joint must be FUSED - Maintain a high index of suspicion
