History
Presentations of calcium pyrophosphate deposition (CPPD) disease include the following [14] :
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Asymptomatic CPPD, as an incidental radiographic finding
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Acute pseudogout
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Pseudo-osteoarthritis
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Pseudo–rheumatoid arthritis
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Pseudo–neuropathic joints
Asymptomatic (lanthanic) CPPD
This is usually associated with radiographic findings of chondrocalcinosis in the absence of clinical manifestations and may be the most common form of CPPD.
The classic radiologic findings include chondrocalcinosis of the hyaline cartilage and fibrocartilage of the knees, the fibrocartilage of the triangular ligament of the wrist, the fibrocartilage of the symphysis pubis, and the acetabulum labrum of the hips.
Acute pseudogout
Acute pseudogout is characterized by acute monoarticular or oligoarticular arthritis. Pseudogout usually involves the knee or the wrist, although almost any joint can be involved, including the first metatarsophalangeal (MTP) joint, as occurs in patients with gout. This form of CPPD accounts for 25% of cases. Glucose levels are usually normal.
Clinical manifestations are similar to those of acute gouty arthritis—typically an acute monoarthritis with pain and swelling—although generally not as intense. Polyarticular attacks may occur on occasion. Pseudogout may be precipitated by medical illness such as myocardial infarction, congestive heart failure, or stroke or may occur after surgery. Trauma may also be a precipitating factor. Events that affect serum calcium levels also may precipitate attacks of pseudogout.
Occasionally, pseudogout may present as a pseudoseptic syndrome with acute arthritis, fever, and leukocytosis with a left shift.
Pseudo-osteoarthritis
Pseudo-osteoarthritis often involves the metacarpophalangeal (MCP) joints, wrists, elbows, and shoulders—joints unlikely to be involved in primary osteoarthritis. Most commonly, however, it affects the knees, and it can involve the proximal interphalangeal (PIP) joints and spine, as occurs in patients with primary osteoarthritis. Pseudo-osteoarthritis accounts for 50% of all CPPD cases. Approximately half of these patients also have associated pseudogout.
Pseudorheumatoid arthritis
Pseudorheumatoid arthritis in patients with CPPD involves symmetrical inflammation of the PIP and MCP joints. Clinically, these patients complain of morning stiffness and joint swelling. In a study from Finland, the prevalence of CPPD in 435 patients with early seronegative rheumatoid arthritis was 3.9% overall, but the percentage was 7.0% in patients age 60 years or older at baseline. [15]
Pseudoneuropathic joints
Neuropathic-like arthropathy, which is observed in fewer than 5% of patients with CPPD, most commonly involves the knee. This is a severe, destructive arthropathy. Unlike true neuropathic arthropathy, no clear underlying neurologic disorder is present. The presence of chondrocalcinosis can aid in making the diagnosis.
CPPD can present as spondylodiscitis. This was shown in 2 case reports, one in a 75-year-old woman who presented with neck pain and in whom magnetic resonance imaging showed spondylodiscitis based on contrast enhancement of C5-C6 vertebrae corpus, and the other in a 61-year-old woman with spondylodiscitis at the C5-C6 intervertebral disc. [16]
Physical Examination
The physical examination findings vary depending on the form of CPPD in a given patient, who may present with an acute arthritis or different patterns of chronic arthritis.
Acute pseudogout
Physical examination findings show an acutely inflamed joint with swelling, effusion, warmth, tenderness, and pain on range of motion similar to acute gouty arthritis. This typically occurs in the knee but may be present in the wrists, shoulders, ankles, hands, and feet.
Pseudo-osteoarthritis
Physical examination findings show a picture similar to osteoarthritis, sometimes with an unusual joint predilection. If a patient has osteoarthritis involving the MCP joints and wrists, consider CPPD associated with an underlying metabolic disease.
Pseudorheumatoid arthritis
Physical examination findings show a picture similar to rheumatoid arthritis, with synovitis in a symmetrical, polyarticular pattern, especially involving the wrists and MCP joints.
Complications
Common complications from CPPD include acute synovitis and chronic degenerative arthritis, which is expected from the various phenotypes (ie, pseudogout, pseudo-osteoarthritis, pseudorheumatoid arthritis). Joint destruction from a neuropathic-like arthropathy is very rare. In addition, case reports of invasive (tumoral or tophaceous) CPPD have been reported. Kudoh et al reported a case of tophaceous pseudogout of the temporomandibular joint extending to the base of the skull in a 38-year-old man. [17] Tumoral pseudogout of a PIP (proximal interphalangeal joint) with an enlarging calcified mass and secondary bony erosion was reported by Park et al. [18]
Coexistent infection with CPPD is a possible complication but the occurrence rate for this is not established. However, evaluation for coexistent infection should be performed when clinically indicated. Tuberculosis of the wrist accompanied by calcium pyrophosphate deposition was reported by Watanabe et al. [19]
Crowned dens syndrome (calcific deposits in the cruciform and alar ligaments surrounding the odontoid process of the second cervical vertebra [the dens], which appear as a 'crown' surrounding the top of the dens on imaging studies) may complicate CPPD. Patients with crowned dens syndrome typically present with localized pain at the base of skull/back of the neck, neck stiffness, and systemic evidence of inflammation (eg, fever and elevated levels of inflammatory markers). [20] Haikal et al reported that cervical computed tomography (CT) scans revealed crowned dens syndrome in 34 of 57 patients with CPPD, and recommended considering cervical CT in elderly patients with neck pain in the setting of CPPD. [21]
Odontoid fracture with nonunion rates are significantly higher in CPPD patients. This illustrates the importance of making the appropriate diagnosis and deciding on treatment. [22]
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Calcium pyrophosphate deposition disease. Radiograph of the knee showing chondrocalcinosis involving the meniscal cartilage, as well as evidence of osteoarthritis.
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Calcium pyrophosphate deposition disease. Radiograph of the wrist and hand showing chondrocalcinosis of the articular disc of the wrist and atypical osteoarthritis involving the metacarpophalangeal joints in a patient with underlying hemochromatosis.
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Calcium pyrophosphate deposition disease. Appearance of calcium pyrophosphate dihydrate crystals obtained from the knee of a patient with pseudogout. The crystals are rhomboid-shaped with weakly positive birefringence, as seen by compensated polarized microscopy. The black arrow indicates the direction of the compensator.
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Calcium pyrophosphate deposition disease. High-powered view of calcium pyrophosphate dihydrate crystals with compensated polarized microscopy. The black arrow indicates the direction of the compensator. Crystals parallel to the compensator are blue, while those perpendicular to the compensator are yellow.
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Calcium pyrophosphate deposition disease. High-powered view of calcium pyrophosphate dihydrate crystals with compensated polarized microscopy. The crystals parallel to the compensator were blue, while those perpendicular to the compensator were yellow. However, the crystals have been rotated 90%, resulting in a color change in both of them. The direction of the compensator was not changed and is indicated by the black arrow.
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Calcium pyrophosphate deposition disease. Ultrasonography of the wrist demonstrates chondrocalcinosis.
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Intraoperative photographs demonstrate extensive precipitate deposition of the calcium pyrophosphate crystals in the articular cartilage, meniscus, and synovium of a knee. Left images depict femoral and tibial surfaces. Right images depict anterior cruciate ligament.
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Intraoperative photographs demonstrate extensive precipitate deposition of the calcium pyrophosphate crystals in the articular cartilage, meniscus, and synovium of a knee. Upper left image depicts anterior horn medial meniscus. Lower left image depicts undersurface of meniscus. Upper right image depicts medial femoral condyle. Lower right image depicts synovium.
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Calcium pyrophosphate deposition disease. Ultrasound scan of the triangular fibrocartilage complex (TFCC) of the wrist shows thin hyperechoic bands parallel to the surface of the hyaline cartilage. Other findings include a punctate pattern consisting of several hyperechoic spots and homogeneous hyperechoic nodular or oval deposits in the articular surface.
