Musculoskeletal Injuries
Answers
292.The answer is d.(Tintinalli, pp 1665-1681.)Thescaphoidis the
most common carpal bone injured in a fall on the outstretched hand
(a “FOOSH”injury). On examination, patients exhibit tenderness at the
anatomic snuffbox and pain referred to the anatomic snuffbox with longitu-
dinal compression of the thumb. In the setting of a tender thumb, a thumb
splint should be applied until films can be repeated after 1 week since initial
films may not reveal the fracture. The application of the splint is especially
important, because of the scaphoid’s high risk for avascular necrosis.
(a)Triquetrum dorsal chip injury is the second most common carpal
bone fracture and occurs with a FOOSH or direct blow to the dorsum of the
hand.(b)Lunate fracture is the third most common carpal fracture. This
injury is also at risk for avascular necrosis and any suspected injury should
be placed in a thumb spica splint. (c)The capitate is the largest carpal bone
and comprises 5% to 15% of all carpal fractures. (e)The pisiform is the only
carpal bone with one articulation (the triquetrum). Anatomically it is impor-
tant because the deep branch of the ulnar nerve and artery pass in close
proximity to the radial surface of the bone. It is an uncommon fracture.
293.The answer is a.(Simon and Koenigsknecht, pp 1591-1592.)Pseudogout
is the most common cause of acute monoarticular arthritisin the elderly.It
affects woman and men equally, primarily after their sixth decade of life. It is
caused by the deposition of calcium pyrophosphate crystals.The knee is the
most commonly involved joint, followed by the wrist and ankle. The synovial
fluidreveals rhomboid-shaped crystalsthat are weakly positive birefrin-
gentunder polarized light. Treatment is generally supportive with NSAIDs.
Gout(b)occurs commonly in middle-aged men and elderly adults.
Uric acid crystals usually deposit in the lower extremities, particularly the
great toe (podagra). Evaluation of synovial fluid reveals needle-shaped
crystals that exhibit negative birefringence under polarized light. Septic
arthritis(c)is a medical emergency that most commonly affects the knee in
adults. Joint fluid generally reveals greater than 50,000 WBC/mm^3 with
mostly neutrophils. Rheumatoid arthritis (d)is an autoimmune disease
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