Lumbar disc herniation: Is there an association between histological and magnetic resonance imaging findings?
BACKGROUND
Although validated radiological scoring systems and histological scoring system of surgically removed degenerated disc are used in assessment of progression of intervertebral disc degeneration, there have not been many studies that integrate these two aspects of assessments. The data available in this respect are very limited. This clinical study was designed to find the correlation between quantitative radiological score (Pfirmann grading system and Modic changes [MC]) and quantitative histological degeneration score (HDS).


METHODS
A cohort of 77 patients (45 males, 32 females; mean age of 38 years [range 18-58 years]) who presented with complaints of discogenic pain or radiculopathy at single level were assessed radiologically. They were graded according to the radiological pattern. The surgically excised disc specimen was graded according to HDS. The degree of radiological changes were correlated with the degree of histological changes.


RESULTS
Though the overall HDS (0-15) did not show statistically significant correlation with Pfirmann grading system, there were positive association found between mucoid degeneration, chondrocyte proliferation with the Pfirmann grading and mucoid degeneration, which were statistically significant. Female sex also had a higher association with instability pattern.


CONCLUSIONS
The study shows that the Pfirmann grading system, MCs and HDS can reliably be used as scoring systems for assessing lumbar disc degeneration. The radiological assessment can be used as a noninvasive tool to assess the probable change in content rather than the microstructure of a disc undergoing degeneration.
Department of Orthopedics and Spine Surgery, Government Medical College, Thiruvananthapuram, Kerala, India, INdia.
Shiju A
SA
Majeed
Department of Orthopedics and Spine Surgery, Government Medical College, Thiruvananthapuram, Kerala, India, INdia.
N Arun Kumar
NA
Seshadrinath
Department of Pathology, Government Medical College, Thiruvananthapuram, Kerala, India.
Kavitha Ravi
KR
Binoy
Department of Pathology, Government Medical College, Thiruvananthapuram, Kerala, India.
Laila
L
Raji
Histological degeneration score; IV Disc displacement; Interventional disc; Modic changes; Pfirmann grading; disc; herniated; lumbar disc herniation; magnetic resonance imaging; surgical discectomy