Devoted to diagnostic and interventional spine imaging and therapeutics

Library

Follow Up of Modic Changes in Patients Treated with Dynamic Neutralisation System for the Lumbar Spine 2008

General Spine

Fras Dakhil-Jerew, MRCS,
JOHN SHEPPERD, FRCS, Non ASSR Member

Scientific Paper

Purpose

In this study we describe changes in lumbar spine MRI following surgical treatment of degenerative disc disease (DDD) using Dynesys.
Modic changes have been described in DDD. Type I represents the inflammatory phase whereas Type II describes fatty changes within the vertebral marrow and endplate. Type III is more advanced degeneration and it indicates marked sclerosis adjacent to endplates.

Methods & Materials

Postoperative MRI has been compared to preoperative scans in 35 patients treated with Dynesys. Primary parameters assessed were Modic changes within treated disc levels and their adjacent segments. Secondary findings were disc bulge and degree of disc degeneration (modified Pearce classification) throughout the whole lumbar spine, facet joint degeneration, pedicle screw positions. Average time to postoperative MRI was 36 months.

Results

Within Dynesys-treated levels, the vast majority of our cohort had Modic change II which did not change following treatment. Few patients, however, progressed from Modic I to Modic II.

Similarly, most of the Dynesys-adjacent levels did not show Modic changes but there were few patients who progressed from Modic I to Modic II.

The commonest disc level operated upon was L4/5. It showed grade II generation which did not differ from postoperative position. Among the adjacent levels, there was slight progress with degenerative process at disc levels L2/3, L3/4 and L4/5.

Most of the preoperative disc bulge were moderate-severe whereas they were ranked as mild-none postoperatively.

Surprisingly the facet joints showed more degeneration as compared to preoperative state at both Dynesys and its adjacent levels.

Conclusion

Dynesys could halt the progress of Modic changes at the treated level(s) though few cases continued with the process of degeneration. This was parallel with the grade of disc degeneration which, in general, did not show further worsening.
Dynesys biomechanics favour shifting of the axis of rotation posteriorly which may explain why our patients had facet joint violation.

References

No financial issues to disclose