Calcified Thoracic Disc - A descriptive classification with clinical and management implications.

Introduction and objective: Thoracic disc calcification is a radiological finding which may be incidental or diagnosed in patients presenting with myelopathy due to spinal cord compression. We performed a study to analyze the imaging patterns of calcified thoracic discs (CTDs).

Patients and methods: A retrospective review of the spinal and radiology database of a tertiary referral orthopedic hospital was conducted for the incidence of CTDs between 2007 and 2020. Patients' demographics and radiological findings were recorded. The relationship between disc size, morphology, spinal cord compression, and management was assessed.

Results: Fifty-one cases of CTDs were identified. The mean size of CTD was 806.2 mm³ (range: 144-2340). The most common level of disc calcification was T9-T10 (24%) in 12 patients. Thoracic disc calcifications in our series commonly involved disc "protrusion" in 67% (34 patients), followed by "mushroom" type in 31% (16 patients) and "extrusion" in 2% (1 patient). 37% (19 patients) had spinal cord compression with 12% (6 patients) undergoing surgical interventions. There was no statistically significant difference in the mean sizes of CTD between the groups with and without spinal cord compression (P = 0.566, independent sample t-test). Patients with "mushroom" type calcification were more likely to have surgical intervention (P = 0.01, Fisher's exact test).

Conclusion: Thoracic disc calcifications, while common, can still be underdiagnosed till late myelopathic deterioration. Care of the elderly physicians, spinal surgeons, and radiologists need to be aware of them to guide diagnosis and management. Our study demonstrates that disc morphology plays a vital role in myelopathic presentation and therefore determines the need for surgical intervention instead of the absolute size of disc calcification.