Effects of chondroitinase ABC on intradiscal pressure in sheep: an in vivo study.

STUDY DESIGN

In vivo intradiscal measurements of pressure in lumbar discs treated with chondroitinase ABC were performed.

OBJECTIVE

To determine the decrease in lumbar intradiscal pressure after chemonucleolysis by chondroitinase ABC in sheep.

SUMMARY OF BACKGROUND DATA

No previous study has assessed in vivo intradiscal pressure after chemonucleolysis. This study investigated the effect of chondroitinase ABC on intradiscal pressure in terms of a dose and time relation. It also included roentgenographic observations and evaluation of the correlation between disc space narrowing and decrease in intradiscal pressure.

METHODS

Chondroitinase ABC was injected in the lumbar intervertebral discs of sheep at doses of 1, 5, and 50 U. Phosphate buffered saline also was injected as a negative control measure. One week before injection, then 1 and 4 weeks afterward, intradiscal pressure was measured using a catheter microtip pressure transducer. Simultaneously, standard lateral roentgenographs were taken, and the disc height index was calculated.

RESULTS

The intradiscal pressure clearly was decreased 1 week after chondroitinase ABC injection. A further decrease was observed up to 4 weeks. This pressure decrease was dose dependent. The disc height indexes also decreased with time, but the state of the change was different from that of the changes in intradiscal pressure. No clear quantitative correlation was found between intradiscal pressure and disc height index.

CONCLUSIONS

Chondroitinase ABC can induce the reduction of intradiscal pressure in the lumbar spine.