26 - Bone Graft Delivery to the Prepared Disk Space in MIS T-Lif and L-Lif...

#26 Bone Graft Delivery to the Prepared Disk Space in MIS T-Lif and L-Lif Procedures: A Problem Solved

MIS Techniques and Outcomes

Poster Presented by: J. Kleiner

Author(s):

J.B. Kleiner (1)
E.J. Grimberg (2)

(1) Spine Center of Innovation, The Medical Center of Aurora, Aurora, CO, USA
(2) Grimberg Tool Production, Golden, CO, USA

Abstract

Background: Bone graft (BG) delivery to the interbody space is a surgical challenge. A variety of strategies are available which empirically insert variable volumes of BG. Device jamming, cumbersome administration or use of off-label biologics has frustrated this step in arthrodesis.

Purpose: The objective of this report was to evaluate a BG delivery device in consecutive patients undergoing transverse lumbar interbody fusion (T-LIF) and lateral interbody fusion procedures (L-IF).

Study Design: Patients undergoing spinal fusion using either T-LIF or L-IF technique during the period January, 2011- March, 2011 had BG applied to the intradiscal space utilizing this device.

Patient Sample: 95 patients had BG applied using this tool; 72 T-LIF procedures from T12-S1, and 23 patients had L-IF procedures T12-L5. Male and female patients were equally matched and the age distribution ranged from 36-87 years. A total of 76 disks were treated with T-LIF, 66 of which were at the L4-5 or L5-S1 level. 32 disks were treated with L-IF, 22 of which were at the L2-3 or L3-4 level.

Outcome Measures: Evaluation of disk space filling with BG, arthrodesis status by X/R and visual analog pain level were used to assess response to treatment.

Methods: A slurry of BG material consisting of tricalcium phosphate, hyaluronic acid, local BG and bone marrow aspirate concentrate was mixed and administered through the device after microendoscopic disk debridement. The delivery device is a custom designed, patent-pending tool, which has an ovoid cross section, a tapered tip and biportal, lateral extrusion sites for BG egress. It has a volume 7ml volume. A detachable funnel allows for additional BG to be administered.

Results: The non-fluid BG material flowed through the device without jamming and the disk space was filled entirely. The tapered tip allowed for entrance into a collapsed disk space without endplate injury. Twice the volume of BG was delivered to each disk space relative to historical controls. Filling of the disk space with BG was evident on imaging studies. Clinical results using visual analog scale showed improvement commensurate with arthrodesis status. No complications were associated with the device. One patient has been found to have a pseudoarthrosis.

Conclusions: BG application is more efficient and complete with this delivery device. A collapsed disk space can be entered due to the tapered tip design and the disk space can be entirely filled with BG material beause of the biportal BG egress; this should substantially decrease pseudoarthrosis risk. Flow dynamics of non-fluid materials through this tool are substantially improved relative to conventional cylindrical applicators.