Methods and devices for delivering therapeutic materials to the intervertebral disc

A method of delivering a therapeutic agent to a nucleus pulposus of an intervertebral disc, the method comprising:

• placing a needle in a retracted position in which a distal end of the needle entirely resides in a first channel of a probe that is disposed about at least a portion of the needle;
• placing the probe in a retracted position in which a distal end of the probe entirely resides in a second channel of a cannula, the cannula comprising a distal end with a beveled tip sharper than a tip of the needle and is disposed about at least a portion of the probe;
• inserting at least a portion of the delivery tool into a body towards an annulus fibrosus of the intervertebral disc, the delivery tool comprising the cannula, the probe and the needle;
• using the beveled tip of the cannula to penetrate through the annulus fibrosus while the needle and probe are in their retracted positions;
• causing the needle and probe to simultaneously slide within the second channel towards a free end of the cannula such that the probe and needle transitions from their respective retracted positions to respective extended positions in which at least a portion of the distal ends of the needle and probe protrude out from the cannula;
• using the probe to separate a portion of the annulus fibrosus from an endplate of the intervertebral disc;
• advancing the distal end of the needle out of the first channel of the probe and into the nucleus pulposus of the intervertebral disc;
• and
• using the needle to facilitate delivery of the therapeutic agent from the delivery tool to the nucleus pulposus of the intervertebral disc.