Biomechanical comparison of a 2-level Maverick disc replacement with a hybrid 1-level disc replacement & 1-level anterior lumbar interbody fusion

[Justin]

The Spine Journal
Volume 9, Issue 10, October 2009, Pages 830-835

Biomechanical comparison of a two-level Maverick disc replacement with a hybrid one-level disc replacement and one-level anterior lumbar interbody fusion (Technical Report)

Serkan Erkan MDa, b, Yamil Rivera MDb, Chunhui Wu PhDc, Amir A. Mehbod MDb and Ensor E. Transfeldt MDb

aDepartment of Orthopaedics and Traumatology, Celal Bayar University, School of Medicine, Izmir Cad. No.10, Manisa 45050, Turkey
bTwin Cities Spine Center, 913 East 26th Street, Suite 600, Minneapolis, MN 55404, USA
cFoundation for the Advancement of Spinal Knowledge, 913 East 26th Street, Suite 600, Minneapolis, MN 55404, USA. Copyright © 2009 Elsevier Inc. All rights reserved.

Background context

Multilevel lumbar disc disease (MLDD) is a common finding in many patients. Surgical solutions for MLDD include fusion or disc replacement. The hybrid model, combining fusion and disc replacement, is a potential alternative for patients who require surgical intervention at both L5–S1 and L4–L5. The indications for this hybrid model could be posterior element insufficiency, severe facet pathology, calcified ligamentum flavum, and subarticular disease confirming spinal stenosis at L5–S1 level, or previous fusion surgery at L5–S1 and new symptomatic pathology at L4–L5. Biomechanical data of the hybrid model with the Maverick disc and anterior fusion are not available in the literature.

Purpose

To compare the biomechanical properties of a two-level Maverick disc replacement at L4–L5, L5–S1, and a hybrid model consisting of an L4–L5 Maverick disc replacement with an L5–S1 anterior lumbar interbody fusion using multidirectional flexibility test.

Study design

An in vitro human cadaveric biomechanical study.

Methods

Six fresh human cadaveric lumbar specimens (L4–S1) were subjected to unconstrained load in axial torsion (AT), lateral bending (LB), flexion (F), extension (E), and flexion-extension (FE) using multidirectional flexibility test. Four surgical treatments—intact, one-level Maverick at L5–S1, two-level Maverick between L4 and S1, and the hybrid model (anterior fusion at L5–S1 and Maverick at L4–L5) were tested in sequential order. The range of motion of each treatment was calculated.

Results

The Maverick disc replacement slightly reduced intact motion in AT and LB at both levels. The total FE motion was similar to the intact motion. However, the E motion is significantly increased (approximately 50% higher) and F motion is significantly decreased (30%–50% lower). The anterior fusion using a cage and anterior plate significantly reduced spinal motion compared with the condition (p<.05). No significant differences were found between two-level Maverick disc prosthesis and the hybrid model in terms of all motion types at L4–L5 level (p>.05).

Conclusion

The Maverick disc preserved total motion but altered the motion pattern of the intact condition. This result is similar to unconstrained devices such as Charité. The motion at L4–L5 of the hybrid model is similar to that of two-level Maverick disc replacement. The fusion procedure using an anterior plate significantly reduced intact motion. Clinical studies are recommended to validate the efficacy of the hybrid model.

Maverick; Total disc replacement; Fusion; Biomechanics

[Fuzzy]

Thanks, Justin.

I am a living specimen of the hybrid procedure discussed above and in real life have more flexibility then I did before the procedure in all ways. And no more pain makes a big difference moving around every day.

[Justin]

Thanks, Justin.

I am a living specimen of the hybrid procedure discussed above and in real life have more flexibility then I did before the procedure in all ways. And no more pain makes a big difference moving around every day.

Thanks for sharing, Fuzzy. Your personal experience is priceless to Spine Patient around the world. :thumpup:

[Katie]

The hybrid was what Dr. Bitan wanted to do on me. I was never sure if he believed in the hybrid itself, or whether he was just limited to using single level ADR because of FDR restrictions.

I was happy to have either two level ADR or the hybrid. My last surgeon was hoping to use one ADR and two fusion from the L3/4, 4/5 and L5/S1. I would like to learn more about the comparisons with these two options.

Thanks again Justin.