REIDER PART 204

264 Charter 7_Lower Leg, Foot> and Ankle

Figurę 7-25. Intractable plantar keratosis (arrow).

alignment of the forefoot to the hindfoot should be neu-tral. If the forefoot appears deviated laterally in relation to the hindfoot, then forefoot abduction (forefoot abductus) is considered to be present. Forefoot abduction is usually associated with pronation of the forefoot. Forefoot abduction can occur as a consequence of flatfoot, either congenital or acquired, or following a mid-foot fracture. If the forefoot seems deviated medially in relation to the hindfoot, forefoot adduction (forefoot adductus) is considered to be present (Fig. 7-31 A). Forefoot adduction may be the residuum of a pediatrie clubfoot or skewfoot deformity.

Figurę 7-26. Heloma molle of fourth toe.

Lower Leg. The anterior viewpoint is the best perspcc-tive for assessing tibial alignment. Normally, the tibia should appear straight. Tibia vara, or bowed tibia, may be due to a malunited fracture, metabolic disorders such as rickets, or congenital or developmental anomalies, such as Blount’s disease. Evaluation of tibial torsion, or rotational alignment, is described in the Alignment sec-tion of Chapter 5, Pelvis, Hip, and Thigh.

Medial Aspect

Arch. Inspecting the foot from its medial aspect allows the examiner to assess the alignment and the integrity of the medial longitudinal arch. Although there are no uni-versally accepted criteria for what constitutes a normal arch, the medial border of the foot from just behind the first metatarsal head to a point about 2 cm distal to the calcaneal tuberosity should be elevated from the floor when the subject is standing. The apex of this arch is usually about 1 cm. Jack described a generał system for grad-ing the morphology of the medial longitudinal arch. A grade I arch is subjectivcly normal or slightly depressed on weightbearing. In a grade II arch, the entire medial border of the foot touches the floor but its edge is straight. In a grade III arch, the entire medial border of the foot not oniy touches the floor but also bulges toward the examiner in a convex manner.

A foot with a high arch is called pes cavus (see Fig. 7-21 A). When present, it is usually bilateral. Pes cavus may be idiopathic or associated with a congenital anomaly, muscle imbalance, or neurologie disorder such as Charcot-Marie-Tooth disease. Unilateral pes cavus may be secondary to tethering of the spinał cord.

When the medial arch is minimal or entirely absent, pes planus is said to be present (see Fig. 7-2IB). Pes planus is morę common in some ethnic groups and may be genetically determined. Pes planus can also be acquired in the adult in association with trauma, contrac-ture of the Achilles tendon, degeneration and rupture of the posterior tibial tendon, or rheumatoid arthritis and other rheumatologic disorders. Although frank pes planus is readily observed, milder deformities are easy to overlook. In subtle cases, comparison with the other foot is important. Unilateral pes planus is usually associated with the too-many-toes deformity, which is described later as part of the posterior inspection.

Diabetic patients may present with an even morę profound deformity, in which the bottom of the foot has a convex or rocker bottom appearance where the longitudinal arch should be (see Fig. 7-31B). This deformity is due to the neuropathic Charcot arthropathy that is itself a consequence of the peripheral neuropathy common in diabetic patients. In Charcot’s arthropathy, the loss of protective sensation leads to progressivc deterioration of the articular structures of the foot. In the earlier stages of this disorder, the foot may have minimal deformity while showing swelling and erythema suggestive of an acute