Orthopaedics: Ankle

Ankle

Evaluation of Ankle and Foot Complaints

Special Tests

·                 anterior drawer: examiner attempts to displace the foot anteriorly against a fixed tibia

·                 talar tilt: foot is stressed in inversion and Bllgle oftala.r rotation is evaluated by x-ray

X-Ray

·                 AP, lateral

·                 mortise view: ankle at 15° of internal rotation

o       gives true view of ankle joint

o       joint space should be symmetric with no talar tilt

·                 Ottawa Ankle Rules should guide use of x-ray

·                 ± CT to better characterize fractures

Ankle Fracture

Mechanism

·                 pattern of fracture depends on the position of the ankle when trauma occurs

·                 generally involves

o       lpsilateral ligamentous tears or transverse bony avulsion

o       contralateral shear fractures (oblique or spiral)

·                 classification systems

o       Danis-Weber

o       Lauge-Hansen: based on foot's position and motion relative to leg

Danis-Webar Classification (Figure 45)

·                 based on level offibular fracture relative to syndesmosis

·                 Type A (infra-syndesmotic)

o       pure inversion injury

o       avulsion of lateral malleolus below plafond or torn calcaneofibular ligament

o       ± shear fracture of medial malleolus

·                 Type B (trans-syndesmotic)

o       external rotation and eversion (most common)

o       ± avulsion of medial malleolus or rupture of deltoid ligament

o       spiral fracture of lateral malleolus starting at plafond

·                 Type C (supra-syndesmotic)

o       pure external rotation

o       avulsion of medial malleolus or tom deltoid ligament

o       ± posterior malleolus may be avulsed with posterior tibio-fibular ligament

o       fibular fracture is above plafond (called Maisonneuve fracture if at proximal fibule)

o       frequently tears syndesmosis

Treatment

·                 undisplaced: non-weight bearing below knee cast

·                 indications for ORIF

o       all fracture-dislocations

o       most of type B, and all of type C

o       trimalleolar (medial, posterior; lateral) fractures

o       talar tilt >10°

o       medial clear space on XR greater than superior clear space

o       open fracture/open joint injury

·                 high incidence of post-traumatic arthritis

Ligamentous Injuries

Medial Ligament Complex (deltoid ligament)

·                 eversion injury

·                 usually avulses medial or posterior malleolus and strains syndesmosis

Lateral Ligament Complex (ATF, CF. PTF)

·                 inversion injury

·                 ATF most severely injured if ankle is plantar flexed

·                 swelling and tenderness anterior to lateral malleolus

·                 ++ ecchymoses

·                 +ve ankle anterior drawer

·                 may have significant medial talar tilt on inversion stress x-ray

Treatment

·                 microscopic tear (Grade I)

o       rest, ice, compression, elevation (RICE)

·                 macroscopic tear (Grade II)

o       strap ankle in dorsi1leDon and eversion x 4--6 weeks

o       PT: strengthening and proprioceptive retraining

·                 complete tear (Grade III)

o       below knee walking cast 4-6 weeks

o       PT: strengthening and proprioceptive retraining

o       surgical intervention may be required if chronic symptomatic instability develops