You are shown the knee x-ray of a 64 year-old man (see below). You are given
no information as to the patient's history, physical findings, or laboratory findings.
What is your diagnosis, what additional test(s) would you perform to confirm
your diagnosis, and what treatment, if any, do you recommend?
DIAGNOSIS: Chondrocalcinosis - AKA Calcium Pyrophosphate Deposition Disease (CPPD)
or pseudogout.
CPPD is estimated to affect 4 to 7% of the adult population in Europe and the
United States. In radiographic examinations that include the knee, pelvis and wrist,
CPPD is detected in 44% of patients older than 84 years of age; the prevalence doubles
with each decade over 60 years of age, and is often found in the context of osteoarthritis.
Persons with hemochromatosis, hyperparathyroidism, hypomagnesemia, hypophosphatasia,
and gout are at increased risk of developing CPPD. Mutations in the CCAL2 locus on
chromosome 5p and the CCAL1 locus on chromosome 8 have been identified in persons
with familial CPPD.
Acute onset CPPD resembles acute gout except for the distribution of joint involvement
- the knee and wrist in CPPD, the ankle and metatarsal joints in acute gout. Chronic
forms of CPPD often resemble and/or accompany osteoarthritis.
The diagnosis of CPDD is established by radiography (see image below) and by
demonstrating the presence of positively birefringent rhomboid-shaped crystals in
the affected joint's synovial fluid.
CPPD treatment options include intraarticular glucocorticoids, oral colchicine,
nonsteroidal antiinflammatory drugs, and low-to-moderate doses of oral glucocorticoids.
Calcium pyrophospate crystals are evident in the knee cartilage of the presented case.
BONUS QUESTION ANSWERS: True or False. 1. The murmur of aortic stenosis may radiate to the paraspinal region of the back. True. The murmur of aortic stenosis is widely radiating and may, rarely, even be detected over the elbow joint. 2. The murmur associated with a ruptured tendon of the posterior leaflet of the mitral valve radiates to the left axilla. False. The murmur radiates upward toward the cranium. The murmur associated with a ruptured tendon of the anterior leaflet radiates to the left axilla. 3. The murmur of aortic insufficiency resulting from an aortic aneurysm radiates along the right sternal border. True. In contrast, the murmur of aortic insufficiency due to valvular incompetence radiates to the mid-sternum. 4. The murmur of mitral stenosis decreases with exercise. False. The murmur of mitral stenosis can often be heard only after the patient has exercised. 5. Right-sided murmurs increase with inspiration. True.
Citation: Rosenthal A.K., Ryan, L.M. Calcium pyrophosphate deposition disease. N Engl J Med. 2016. 374(26): 2575-2584.