In this issue, Moon et al. provide a detailed report on two cases of Calcium pyrophosphate deposition disease (CPDD), causing compression of the spinal cord and conus medullaris requiring surgical decompression and reconstruction [1].Both cases presented on elderly patients, with known advanced degenerative disease of the spine. In both cases the mass was likely forming from the facet joint and both cases presented with a combination of severe pain and symptoms of neural compression (in different degrees, causing alteration of the spinal cord motor tracts in one case and unilateral lower limb pain mimicking radiculopathy in the second one). Both patients gained full resolution of symptoms and neurological function after surgery.A number of cases of CPDD affecting the spine have been described in the literature, but most reports include one or few cases, which suggests that CPDD requiring surgery is relatively unfrequent. This is in contrast with the finding of high prevalence (as high as 25%) of deposits of calcium pyrophosphate in the cervical spine of patients with pseudogout affecting peripheral joints [2].While the association of pseudogout with lumbar and cervical stenosis has been well described, some aspects of this condition deserve some attention. The prognosis of spinal canal decompression in patients with CPDD does not seem to be worse than that on patients with degenerative lumbar stenosis [3]. CPDD can also need to be distinguished from other spinal conditions, such as tumors [4], spinal infection [5], hematoma of the yellow ligament [6]. One of the two cases in this report presented with severe spinal sagittal misalignment that might be related to either the spinal cord compression or inflammation of the facet joints, and resolved after surgery, which suggests that CPDD can also be misinterpreted as spinal deformity of functional nature [7].
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.