Maverick Study Abstract

Prospective Randomized Series Comparing Maverick™ Lumbar Total Disc Replacement (TDR) with Anterior Lumbar Interbody Fusion (ALIF)

Authors: Kenneth A. Pettine, M.D.; E. Jeffrey Donner, M.D.

Study Design: Prospective Randomized Controlled Trial

Introduction: The Maverick is a metal on metal two-piece TDR.  Unique design characteristics include a semi-constrained posterior center of rotation.  This study is an IDE clinical trial with a minimum of two year follow up comparing the Maverick (25 patients) with an ALIF utilizing an LT-CAGE® with INFUSE® Bone Graft (11 patients)

Methods: Patients were blindly randomized 2:1 (Maverick/ALIF). Indications for surgery were similar to lumbar fusion.  Inclusion/exclusion criteria will be discussed. All surgeries were one-level L4-5 (seven procedures) or L5-S1 (29 procedures). Average patient age was 43 in both groups (range 21 to 55), with an average B.M.I of 24 (range 21 to 27).  Surgical technique will be discussed.

Average operating time was 99 minutes (range 68 -118) for the Maverick and 60 minutes (range 53 – 112) for the ALIF.  Blood loss averaged 200cc for Maverick and 78cc for ALIF.

Average hospital stay for both groups was 1.6 days (range 1 to 4)

Time to unrestricted activity averaged 6 weeks in the Maverick group and 6 months in the ALIF group.

Results: Maverick pre-op Oswestry Disability Index (ODI) was 56: one year ODI 15: Two year ODI is 15 with an average improvement of 74%.  ALIF pre-op ODI mean was 58.  One year ODI was 35: Two year ODI was 41 for an average improvement of 29%.

Maverick pre-op mean Visual Analog Scale (VAS) was 7: One year VAS was 3: Two year VAS was 2 for an average improvement of 71%.  ALIF pre-op VAS was 8: One year VAS was 5: Two year VAS was 6 for an average improvement of 25%.

Eleven Maverick patients (44%) had an average pre-op ODI of 55, which decreased to an average ODI of one at two year follow up.  These patients are considered asymptomatic for any lumbar pain.  Twenty-one Maverick patients had a decrease of 15 ODI points meeting requirements of clinical success (84%).  Six ALIF patients had study requirements of clinical success (55%).

One Maverick patient required a re-operation for an infection 18 months post operation.  Three of eleven patients in the ALIF group required posterior fusion for pseudoarthrosis (27%).  One additional patient is awaiting posterior fusion.

Overall patient satisfaction was 95% ofr the Maverick TDR and 78% for the ALIF group.

Conclusions: These Maverick TDR results are similar to those reported by six other IDE sites.  These combined results of 173 Maverick patients indicate statistical superior clinical outcomes compared to ALIF at one and two year follow up.  In this study 44% of the maverick group (11 of 25) were asymptomatic at two year follow up.

Objectives: To evaluate the clinical outcomes of Maverick TDR with ALIF

References: Maverick ™ Total Disc Replacement: Initial report of 24-minth clinical outcomes from six investigational centers: Mathew F. Gamet, M.D., et al. Poster presented at N.A.S.S. 2006.