Foot and Ankle
Core concepts
Foot and ankle questions test anatomic precision and biomechanics. Know the deltoid ligament complex, the syndesmosis (and the gravity stress view), and the lateral ligament anatomy (ATFL, CFL, PTFL). Master hallux valgus: the first metatarsal angle, intermetatarsal angle, and the choice between distal (Chevron), midshaft, and proximal osteotomies or fusion. Understand adult-acquired flatfoot (posterior tibial tendon dysfunction) staging and the role of the spring ligament. Know ankle arthritis management and the indications for arthrodesis versus arthroplasty. For trauma, distinguish stable and unstable ankle fractures (Weber and Lauge-Hansen), and recognize the Maisonneuve injury. Also review Achilles tendon rupture diagnosis (Thompson test) and the diabetic foot (Charcot staging, offloading, and infection).
Traps
The classic trap is missing a syndesmotic injury in a "normal" ankle film; use stress views and measure the tibiofibular clear space. Another is confusing posterior tibial tendon dysfunction with a rigid flatfoot from arthritis or tarsal coalition. Do not forget that a first MTP fusion is a reliable salvage for severe hallux valgus with arthritis.
Rule of thumb
If the ankle mortise is widened or the syndesmosis is suspect, stabilize the syndesmosis; a missed syndesmotic injury leads to chronic instability and arthritis.
Worked example
A 24-year-old with an isolated proximal fibula fracture and medial ankle pain: suspect a Maisonneuve fracture; obtain a full-length tibia/fibula film and stabilize the syndesmosis after reducing the ankle.