In the Journal of Orthopedic Surgery and Research, Robert K. Eastlack, et al, published “Finite element analysis comparing a PEEK posterior fixation device versus pedicle screws for lumbar fusion.

Carlsbad, CA, April 1, 2024 – Spinal Elements, a spine technology company, announced a new publication on Karma Posterior Fixation system. This latest publication compares the stability and load transfer characteristics of Karma cortico-pedicular posterior fixation with those of a conventional pedicle screw system in fusion procedures at the L4-S1 levels using a validated finite element model.

The findings of the study demonstrate that Karma provides comparable stability and effective range of motion reduction to pedicle screws during flexion-extension, lateral bending, and torsion simulations. In addition, Karma exhibited higher anterior load transfer and less stress shielding compared to pedicle screws. These results suggest that Karma may enhance fusion rates by promoting stability and bone growth for interbody procedures. Overall, the results of this finite element analysis study highlight the potential clinical utility of Karma as a viable alternative to pedicle screws in lumbar fusion surgeries. Review the full publication at

Figure 1. L4-S1 spine, color scale (in mm) shows the deformation on lateral bending for the intact spine (left) Karma fixation (middle), and pedicle screw system (right).

Dr. Robert Eastlack, Orthopedic Spine Surgeon at Scripps Hospital commented, “Karma is a great alternative for my 1-2 level degenerative lumbar cases requiring posterior fixation. This data demonstrates the stability of Karma compared to pedicle screws with less stress shielding of the anterior or lateral interbody devices, providing a more natural distribution of loads through the anterior column.”

Karma is a metal-free, cortico-pedicular posterior fixation system designed to meet the unmet needs of the aging spine. It minimizes tissue trauma without the use of screws and rods while providing similar fixation to a pedicle screw system in degenerative spinal conditions. The Karma system provides a simple reproducible procedure using a single set of instruments and a universal PEEK fixation implant. Its extremely low-profile implant compares favorably versus larger metal posterior fixation devices. Karma is part of Spinal Elements’ portfolio of products that are intended to address the unintended consequences of spine surgery.

Ron Lloyd, CEO of Spinal Elements, stated, “This publication demonstrates the stability provided by Karma posterior fixation and lays the foundation for Karma as a clinical solution in spinal fusion procedures, especially for aging spine patients where surgeons are looking for alternatives to pedicle screw systems. As we expand the use of Karma in spine surgery, we look forward to continuing our clinical research and publishing the results.”

Special thanks to all the authors contributing to this publication: Robert K. Eastlack, Pierce D. Nunley, Kornelis A. Poelstra, Alexander R. Vaccaro, Marcus Stone, Larry E. Miller, Pierre Legay, Julien Clin and Aakash Agarwal.

About Spinal Elements

Spinal Elements is a Carlsbad, California-based medical device company focused on the design, development, and commercialization of a comprehensive portfolio of systems, products, and technologies for spine surgery procedures. A leading designer, developer, manufacturer, and marketer of innovative medical devices used in spinal surgical procedures, Spinal Elements combines leading medical device technologies, biologics, and instrumentation to create positive surgical outcomes that exceed surgeon and patient expectations. Spinal Elements has built a reputation delivering innovative and differentiated technologies that enable fundamental shifts in solutions for spine surgery. The company markets a complete portfolio of advanced spinal implant technologies. Learn more at

For more information about Spinal Elements, contact:

Rick Simmons
Chief Marketing Officer
Spinal Elements

About Kohlberg & Company 

Kohlberg is a leading U.S. middle market private equity firm based in Mount Kisco, New York. Over the firm’s 36-year history, the firm has organized 11 private equity vehicles totaling in aggregate over $14 billion. Since inception, the firm’s private equity investments have generated over $10 billion in realized returns with no realized losses since Fund VI (2007 vintage). The firm invests in leading middle market businesses that are identified through its rigorous thematic research and the firm’s White Paper Program in its six core practice areas. Learn more at

For more information about Kohlberg & Company, contact:
Sasha Kim

Kohlberg & Company, L.L.C.
545 Madison Avenue, 12th Fl.
New York, NY 10022
Phone: (646) 595-9438