Pathological studies on calcification of the intervertebral discs

Area of Science:

• Orthopedics
• Rheumatology
• Biomineralization

Background:

• Intervertebral disc calcification is a common finding.
• The exact composition and prevalence of these calcifications, particularly in asymptomatic individuals, require further investigation.
• Understanding the crystalline nature of these deposits is crucial for differentiating them from other pathologies.

Purpose of the Study:

• To characterize the crystalline composition of calcified deposits in human intervertebral discs.
• To determine the prevalence of these deposits in a cadaveric population.
• To correlate microscopic findings with macroscopic observations.

Main Methods:

• Microradiography was used to detect linear and punctate calcified deposits in 35 human cadavers.
• Light microscopy and scanning electron microscopy (SEM) were employed to identify crystal types and morphology.
• Clinical and familial histories were reviewed to exclude known metabolic disorders.

Main Results:

• Calcified deposits were identified in 57% of cadavers via microradiography and 63% via light microscopy.
• Deposits were composed of calcium pyrophosphate dihydrate (CPPD) crystals (linear/flake-like) and dicalcium phosphate dihydrate (DCPD) crystals (punctate).
• SEM revealed CPPD crystals as rod-like, rectangular, or cuboid (4-10 μm), and DCPD crystals as prismatic (20-60 μm).

Conclusions:

• The study demonstrates a high prevalence of intervertebral disc calcification in the absence of clinical signs of articular chondrocalcinosis.
• The identified CPPD and DCPD crystals represent distinct types of biomineralization within the intervertebral discs.
• These findings contribute to the understanding of disc degeneration and crystal deposition diseases.