High Rates of Degenerative Changes in the Lower Spine in Calcium Pyrophosphate Deposition Disease Compared to Degenerative Disc Disease.

Abstract

To assess the effect of calcium pyrophosphate deposition disease (CPPD; chondrocalcinosis) on the axial skeleton and compare it with degenerative disc disease (DDD). Conventional radiographs (CR) and magnetic resonance imaging (MRI) of patients with CPPD or DDD were retrospectively assessed by 2 independent readers for vacuum phenomena, disc calcification, endplate erosion, osteophytes, disc height changes, and spondylolisthesis. Available follow-up CR were assessed. CR from 140 patients with CPPD (1171 discovertebral units [DVU]) and 99 with DDD (803 DVU) were evaluated (mean [SD] age 74.4 [9.9] vs 71 [6.2] years; 20% vs 20.2% male individuals, respectively). Disc calcification, osteophytes, and erosions were noted significantly more frequently in CPPD vs DDD (16.5% vs 5.2%, 73.5% vs 59.8%, and 13.6% vs 3.2%, respectively; all <i>P</i> ≤ 0.002). Follow-up CR from 29 patients with CPPD and 46 with DDD were available. Significant progression of endplate erosions and osteophytes was seen (<i>P</i> ≤ 0.02) in both groups. CR follow-up in the CPPD group was shorter than that in DDD (median [IQR] 1.9 [0.6-3.0] vs 3.0 [1.6-4.7] years, respectively; <i>P</i> = 0.03), but CPPD compared with DDD showed more frequent radiographic erosive changes in the thoracic spine (6.8% vs 0.6%; <i>P</i> = 0.02) and lumbar disc calcification (5.8% vs 0.6%; <i>P</i> = 0.01). CPPD is associated with more severe and progressive structural changes in the lower spine compared to DDD. Differentiating CPPD from DDD has clinical implications, influencing both appropriate management strategies and clinical course estimation.