0071643192.pdf

ORTHOPEDICS

DIAGNOSIS

■ Joint aspiration is the key!

■ Send joint fluid for cell count, crystals, Gram stain, and culture.

■ Considerable overlap of WBC count exists between inflammatory and

infectious etiologies of arthritis. In particular, gout and pseudogout can

have WBC counts >70,000 (see Table 4.8).

■ Peripheral WBC, ESR, and CRP are neither sensitive nor specific but should

be obtained, as they can help with monitoring effectiveness of treatment.

■ X-ray may be helpful to diagnose trauma, tumor, avascular necrosis, or

osteomyelitis.

Sacroiliitis

Sacroiliitis is an inflammation of one or both of the sacroiliac joints.

Causes include

■ Spondylarthropathies, eg, ankylosing spondylarthritis

■ Trauma or overuse

■ Infection, eg, injection drug use

■ Pregnancy

■ Degenerative arthritis

SYMPTOMS

■ Generally vague

■ Low-grade fever

■ Pain in lower back, thighs, or buttocks, especially in the morning or after

prolonged rest

■ Limp

■ Decreased range of motion

EXAM

■ Tender sacroiliac joint

■ Lumbar X-ray: If patient has ankylosing spondylitis, will see bamboo

spine—the squaring off of the vertebral bodies.

■ Positive stork test: The examiner stands behind the patient with his

thumbs over the most posterior portion of the patient’s superior iliac spine.

The patient then flexes their hip and knee on one side to a minimum of

90° (like a stork) while standing straight with the other leg. A normal test is

when the thumb on the side of the bent knee moves caudad in relation to

the thumb with the straight leg. Cranial movement of the thumb suggests

sacroiliac dysfunction. Test both sides.

TABLE 4.8. Features of Synovial Fluid

TYPE WBC/lLCLARITY COLOR

Noninflammatory < 2000 Transparent Clear

Inflammatory 2000–75,000 Cloudy Yellow

Infectious >80,000 Cloudy Yellow

Do not use allopurinol for

acute gout attacks.