REIDER PART 2
19

Chaptek 7_Lower Leg, Foot, and Ankle 279

Figurę 7-50. Palpation of the dorsalis pedis pulse.

extensor retinaculum over the dorsum of the foot. Trauma, tight shoes, and space-occupying lesions are the most common causes of this condition, known as (interior tarsal tunnel syndrome. To check for anterior tarsal tunnel syndrome, the examiner should percuss the dor-sum of the foot in the vicinity of the dorsalis pedis artery in the same manner uscd to pcrform TinePs test. In the prcsencc of an anterior tarsal tunnel syndrome, such per-cussion usually generates a burning pain that radiates to the web space between the first and the second metatarsals, the area of primary sensory distribution of the deep peroneal nerve.

The tendons of the extensor digitorum longus and the

adjacent peroneus tertius lie just lateral to the dorsalis pedis artery. Just distal to the ankle joint, these tendons are restrained by the interior extcnsor retinaculum. The exten-sor digitorum tendons then fan out to each of the lateral four toes. These tendons are usually readiły visible and palpable, especiaUy when the patient is actively dorsiflexing the toes (see Fig. 7-7). Although the tendons themselves are rarely involved in a pathologic process other than laccration, pres-sure from shoes laced excessively tight can cause a tenosyn-ovitis on the dorsum of the foot surrounding the extensor digitorum longus tendons. This condition may cause diffuse tenderness and mild swelling around the extensor digitorum longus tendons in the vicinity of the tarsometatarsal joint.

Maximal passive plantar flexion of the ankle exposes the antcrolateral aspect of the talar dome to palpation (Fig. 7-51 A). With this maneuvcr, the antcrolateral por-tion of the talar dome becomes palpable and often visible between the lateral malleolus and the extensor digitorum longus tendon (Fig. 7-5IB). Oscillating the ankle while palpating can help orient the examiner. Tenderness of the talar dome may rcflect osteochondritis dissecans or a tran-schondral fracture of the dome of the talus.

While maintaining maximal plantar flexion of the ankle, the examiner may palpate the tarsal navicular and intervening talonavicular joint just distal to the ankle. Identification of the navicular tuberosity helps with ori-entation. Prominent osteophytes are palpable when advanced degeneration of the talonavicular joint is pres-ent. Tenderness of the body of the navicu!ar in an athlete should cause the examiner to suspect a navicular stress

Figurę 7-51. A and B, Palpation of the anterolateral aspect of the talar dome.