Discussion of the case
The elderly male patient with polyarthritis and non-inflammatory backache had normal ESR and CRP, and negative HLA-B27, RF, and ANA. The symptoms of backache were not suggestive of inflammatory origin. The pain worsened during activity and rest stiffness was minimal. The flexibility was impaired. The small joints of hands were involved and there was swelling in the knees and ankles, and all joints were tender. Since the inflammatory parameters were normal, the first possibility to be considered is degenerative arthritis. Since the symptoms were persisting for the past 5 years and there was a clinical sign of inflammation in the peripheral joints, it is necessary to rule out the chances of overlapping rheumatoid arthritis, ankylosing spondylitis (AS), and other inflammatory arthritis. In addition, the possibility of other diseases associated with calcification of the disc cannot be ruled out, as the patient's sacroiliac joint shows degenerative changes and the X-ray of the lumbar-sacral spine (Fig. 2) indicates extensive disc calcification.
Intervertebral disc calcification (IDC) has been noted in patients with systemic metabolic conditions like alkaptonuria, hemochromatosis, calcium pyrophosphate dihydrate crystal deposition disease, hyperparathyroidism, acromegaly, and amyloidosis. In some conditions like poliomyelitis, ankylosing spondylitis, juvenile chronic arthritis, and local trauma, it has also been noted as a part of immobilization or fusion of the spine.1,2 The prevalence of IDC in the general adult population has been reported to be around 5-6%.3 The presence of enthesial calcification reveals the possibility of having seronegative spondyloarthropathies like AS and psoriatic arthritis.
Another condition to be considered in the present case is skeletal fluorosis. The patients did not have any sign of fluorosis of a denture. The radiologic features of skeletal involvement include increased bone density (osteosclerosis), osteopenia/osteoporosis, trabecular blurring or haziness, ossification of the attachments of tendons ligaments, and muscles, interosseous membrane calcification, and ossification of the posterior longitudinal ligament. In the present case, the calcification was more in the intervertebral disc (IVD) and ligaments and the osteosclerotic lesions were not prominent. Generally, the occurrence of skeletal lesions without dental staining is rare.
Another possibility is degenerative arthritis and it needs to be differentiated from diffuse idiopathic skeletal hyperostosis (DISH) and AS. In DISH, the calcification is predominantly over the ligament, especially over the anterior and posterior regions than the spine.4 However, in the present case, the calcification being predominant in the IVD, it is difficult to classify the condition as DISH. In DISH, bone proliferation can be seen on the iliac crests, the ischial tuberosities, the pubis, the lateral acetabulum, and the greater and lesser trochanters.4 Resnick et al., have proposed the following criteria for DISH: 1)"flowing" ossification extending over four contiguous vertebrae; 2)relative preservation of intervertebral disc height concerning age, and 3)absence of apophyseal joint ankylosis or sacroiliac changes.8 The pattern of calcification and reduction of disc space noted in the present case suggests that the chance of DISH is less likely.
The small and large joint disease is suggestive of degenerative osteoarthritis. The reports indicate that early changes in osteoarthritis and the calcification of IVD can be a part of degeneration and disc desiccation.5 However, since the patient is aged >60 years, it is necessary to exclude metabolic diseases like alkaptonuria and calcium metabolic disease.
Final Diagnosis
Osteoarthritis of the spine and other joints
Follow-up
The patient was managed on nutrition supplements like glucosamine and had been recommended regular physiotherapy. The patient was symptomatically better.
Learning points
- The different causes of disc calcification need to be evaluated based on the clinical investigations.
- Status of sacroiliitis and the ligamental involvement in the form of calcifications are important in differentiating spine diseases.
- Characterization of syndesmophytes helps in ascertaining diagnosis.
- IVD calcification may occur in a good proportion of patients with the degenerative spine.
References
- Andres TL, Trainer TD. Intervertebral chondrocalcinosis: A coincidental finding possibly related to previous surgery. Arch Pathol Lab Med. 1980; 104(5): 269–271.
- Weinberger A, Myers AR. Intervertebral disc calcification in adults: a review. Semin Arthritis Rheum. 1978; 8(1): 69–75.
- Chanchairujira K, Chung CB, Kim JY, Papakonstantinou O, Lee MH, Clopton P, et al. Intervertebral disk calcification of the spine in an elderly population: radiographic prevalence, location, and distribution and correlation with spinal degeneration. Radiology. 2004; 230(2): 499–503.
- Olivieri ID, Angelo S, Palazzi C, Padula A, Mader R, Khan MA. Diffuse idiopathic skeletal hyperostosis: differentiation from ankylosing spondylitis. Curr Rheumatol Rep. 2009; 11(5): 321–328.
- Mithal A, Trivedi N, Gupta SK, Kumar S, Gupta RK. Radiological spectrum of endemic fluorosis: relationship with calcium intake. Skeletal Radiol 1993; 22(4): 257-261.
- Boillat MA, Garcia J, Velebit L. Radiological criteria of industrial fluorosis. Skeletal Radiol 1980; 5(3): 161-165
- Resnick D. Degenerative diseases of the vertebral column. Radiology. 1985; 156(1): 3–14.
- Utsinger PD, Resnick D, Shapiro R. Diffuse Skeletal Abnormalities in Forestier Disease. Arch Intern Med. 1976; 136(7): 763–768.
