REIDER PART 114

104 Chapter4 Hand and Wrist

Figurę 4-3. Paronychia (arrow).

Dorsal Aspect

The dorsal aspect of the hand and wrist is inspected with the patienfs forearm pronated.

Fingernails. Closest to the examiner are the fingernails, which protect the dorsal tips of the digits and assist in picking up fine objects. (Fig. 4-2). A smooth epony-chium, or cuticle, surrounds the base of the nail. Ideally, the nail itself should be smooth and oval. The nailbed itself, visible through the nail, should be a healthy pink, with the exception of a smali white crescent or lunula at the base of some nails. The color of a nail reflects the cir-culatory status of that particular digit; the color of the nails as a wholc may reflcct the circulatory status of the hand and the cardiovascular function of the patient.

Deformities of the nail are legion and may reflect injury to the nailbed or systemie disease. Common nail deformities include splitting owing to a previously lacer-

Figurę 4-4. Subungual hematoma.

ated nailbed and pitting owing to psoriatic arthritis. Fungal nail infections, morę common in the foot, may also leave the fingernails thickened and deformed. The appearance of the nails may reflect not only the patienfs health status but his or her occupation and personality as well. Swelling around the base of the fingernail, often asymmetric and accompanied by erythema, many times reflects an infection known as a paronychia (Fig. 4-3). Maroon discoloration at the base of the nail usually reflects a subungual hematoma, which often results from a direct blow to the fingertip. (Fig. 4-4) Subungual hematoma may be associated with an underlying fracture of the distal phalanx.

Digits. The digits themselves should appear straight, with transverse wrinklcs marking the locations of two inter-phalangcal joints. The thumb is composed of proximal and distal phalanges linked by an interphalangeal joint. Localized swelling may reflect a specific injury or a morę systemie disease process. Multiple bony nodules around the distal interphalangeal (DIP) joints are known as Heberden’s nodes (Fig. 4—5) and are typical of osteoarthritis. A tnucous cyst is a cystic lesion on the dor-sum of the finger arising from the DIP joint and may deform the fingernail (Fig. 4-6). It is associated with degenerative arthritis of the DIP joint and arises from the joint itself.

Degenerative changes in the proximal interphalangeal (PIP) joints may also occur in osteoarthritis. These firm, bony nodules are known as Bouchard^ nodes (Fig. 4-7). When these joints are involved with rheumatoid arthritis, thcrc are no nodes but the joint

Figurę 4-5. Heberdei^s nodes (arrows).