Craniovertebral junction pathology in high cervical disc disease.

Objective: To establish predisposing factors of high cervical disc degeneration (HCDD) with an emphasis on the presence or absence of craniovertebral junction (CVJ) pathology by a retrospective analysis of clinical and radiologic parameters of patients operated at our institute.

Methods: Thirty-seven patients of C3-4 prolapsed intervertebral disc (PIVD) were compared with 45 patients of C5-6 PIVD. Nurick's grade was used for clinical assessment. Radiological parameters like congenital and osteoarthritic changes at CVJ along with measurement of stress levels in flexion and extension on X-rays were done.

Results: Mean age of C3-4 PIVD patients (48.16 years, range 26-65 years) was significantly higher than C5-6 PIVD patients (38.13 years, range 21-55 years) (p < 0.001). CVJ pathology was seen in significantly higher proportion in patients with C3-4 PIVD (18/37) in comparison to C5-6 PIVD (4/45) (p < 0.001). C3-4 PIVD patients presented with a poorer pre-op and post-op Nurick's grade. T2 hyperintense intramedullary signal change was seen in 91.8% (34/37) of C3-4 PIVD patients as compared to 66.67% (30/45) of C5-6 PIVD patients (p < 0.001).

Conclusion: CVJ pathology is a predisposing factor for HCDD. HCDD presents in a poorer Nurick's grade compared to lower cervical PIVD and majority of the patients have T2 hyperintense intramedullary signal changes in MRI. Presence of T2 hyperintense intramedullary signal changes is associated with poorer pre-op clinical status and poorer post-op outcome.