Interspinous Device Controversies in Understanding Patient Selection: Inspan vs Coflex


L5-S1 Inspan Interspinous Interlaminar Thoracolumbar Fixation for Fusion and Spinal Stenosis compared to Coflex

“Inspan treats the facet and disc pain in all motions because it stabilizes the segment. Therefore, if you have a patient with facet pain, disc pain and spinal stenosis, Inspan treats all three conditions” says Professor Dr. Kingsley R Chin.

An Interview with Board-Certified Harvard Trained Orthopedic Spine Surgeon and Inventor, Professor Dr. Kingsley R Chin


  • HOW DOES INSPAN COMPARE TO COFLEX?


“I’m going to answer that not so much as a competitive comparison but based on treatment, diagnosis, and patient selection.”

Let’s start with patient selection and diagnosis. If the patient has spinal stenosis as the primary pathology and if you are going to perform a midline decompression and place an interspinous device under CPT code 22867, then both Coflex and Inspan could be used as devices for that treatment. The difference is that if you use Coflex, that device is acting as an extension block. When you go into flexion, or bend laterally or rotate, it’s not secure so it is going to have movement and stresses on the spinous processes and that is one of the drawbacks of dynamic extension blocks. Many of these devices, most notably X-Stop, Vertiflex Superion and Coflex, you will see spinous process erosions, spinous process fractures and implant dislocations that can be reviewed on the FDA MAUDE Database for incidences of reported device failures. You will see plenty of examples here but note that there may be several other cases beyond the ones reported.

  • PATIENT SELECTION AND BENEFITS FOR SPINAL STENOSIS?


The Inspan device increases the disc and foraminal heights, fixates and stabilizes the spinous processes and the laminas and therefore the facets. This means that the device treats spinal stenosis but also has a stabilizing impact on the segment in all motions whether in flexion, extension, lateral bending and rotation. This can be beneficial in a patient who is osteoporotic to avoid spinous process fractures, erosions and dislocations of the device. None of these have been reported with Inspan. The other patient selection criteria is facet-related back pain or discogenic mediated back pain. These patients if treated with Coflex or any extension block device, will not get the benefit of pain relief from disc or facets because you are maintaining the same amount of motion as before especially in flexion that is causing the pain. You may get some dampening on the facets in extension if they’re having some amount of back pain on extension. Inspan treats the facet and disc pain in all motions because it stabilizes the segment. Therefore, if you have a patient with facet pain, disc pain and spinal stenosis, Inspan treats all three conditions while Coflex will just be treating spinal stenosis in extension.

  • PATIENT SELECTION AND BENEFITS FOR FUSION?


Next is fusion, if you have a patient with grade 1 or grade 2 spondylolisthesis, severe facet degeneration, disc degeneration and spinal stenosis you can chose to fuse this patient with an interspinous fixation device instead of pedicle screws and interbody cages. You could consider using the Coflex device since they also have a fusion device in which you place a pin between the spinous processes to hold the device in place and the reason for that pin clearly is to avoid the patient having motion in flexion and other planes. Inspan also works well here because the device can achieve rigid fixation of the facets and the spinous processes, and it is a very powerful device for that. If you look at the Inspan footplates they are symmetrical, with very sharp and strong teeth configuration, also long enough such that when the two plates come together, they are fixating almost across the spinous processes. Inspan has been a proven solution for fusion with bone graft and so both devices could be used in these fusion cases instead of traditional pedicle screws but Inspan is a more rigid device than Coflex.

  • INDICATION FOR USE AND FDA APPROVAL?


Inspan is the first interspinous process device to be FDA cleared for both spinal stenosis and fusion from T1 to S1. Coflex is indicated for spinal stenosis from L1 to L5.

INSPAN

Indications For Use

The Inspan ScrewLES Fusion System is a posterior non-pedicle supplemental fixation system intended for use in the noncervical spine (T1-S1). It is intended for plate fixation/attachment to the spinous process for the purpose of achieving supplemental fusion for the following indications: spondylolisthesis, trauma (fracture or dislocation), tumor, degenerative disc disease (defined as discogenic pain with degeneration of the disc confirmed by history and radiographic studies), or lumbar spinal stenosis. The device is intended for use with bone graft material and is not intended for stand-alone use.

https://www.accessdata.fda.gov/cdrh_docs/pdf21/K213266.pdf

COFLEX

Approval Order Statement

Approval for the Coflex interlaminar technology. This device is indicated for use in one- or two-level lumbar stenosis from l1- l5 in skeletally mature patients with at least moderate impairment in function, who experience relief in flexion from their symptoms of leg/buttocks/ groin pain, with or without back pain, and who have undergone at least 6 month of non-operative treatment. The Coflex is intended to be implanted midline between adjacent lamina of 1 or 2 contiguous lumbar motion segments. Interlaminar stabilization is performed after decompression of stenosis at the affected level(s).

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpma/pma.cfm?id=P110008

  • PATIENT SELECTION SUMMARY – INSPAN VS COFLEX?


If you are trying to decide between Coflex and Inspan you should be looking at the two different operations – patients with stenosis and patients who require fusion. Patients with spinal stenosis and pain from the facets or discs should be considered for Inspan to treat the facet pain and the disc pain. If you have concerns about osteoporosis, spinous process fractures or erosions, go with Inspan. If you diagnose facet tropism where the facets are not symmetric on both sides, according to Dr. Scott Boden’s paper, those patients are going to have degeneration of the facets and may also lead to some spondylolisthesis. These patients require a posterolateral fusion, you can consider using Inspan or Coflex plus a biologic such as Nanofuse Biologics (synthetic bioactive glass plus demineralized bone matrix). If you are trying to have the strongest fixation of the facets, Inspan will be the winning choice.

The authors views are a perspective only, and not to be held responsible for any errors or omissions, or for the results obtained from the use of this information. All information in this article is provided “as is” and intended to be used for educational and informational purposes only. Past performance does not guarantee future results and none of the statements in this article are meant to provide any financial, investment, tax, or legal advice that should be independently verified.

About INSPAN, LLC

INSPAN, LLC is privately owned by the KICVentures Group and is focused on advancing the platform of patented interspinous interlaminar fixation technology. The Inspan device has a proven ten-year track record with thousands implanted since FDA clearance in 2010. There are no documented device-related failures or spinous process fractures that have plagued other competitive ISP devices. Click here to review Inspan’s FDA clearance and indications for use

https://myinspan.com/

About KICVentures Group

Our founders have been investing in spine surgery since 2000, which makes us the most experienced healthcare investment holding company with the largest portfolio of medical device technologies focused on solutions for less invasive outpatient spine surgery. Our investment strategy is to acquire or invent disruptive technologies using our own capital or partner with private individual investors. This allows us the freedom to make quick and nimble long-term decisions with leading physicians to advance clinical outcomes, such as when we acquired AxioMed Viscoelastic Disc Technologies, while the leading spine companies look the other way to invest in advancing spinal fusion.

https://www.kicventuresgroup.com/

AUTHORS

Aditya Humad is the Co-Founder & CFO of the KICVentures Group, and previously on Wall Street as an investment banker at JPMorgan Healthcare M&A. He studied Bioengineering at the University of Pennsylvania and Finance at the Wharton School of Business.

Dr. Kingsley R. Chin MBA is a board-certified Professor of Orthopedic Spine Surgery and honors graduate of Harvard Medical School and the Harvard Combined Orthopedic Residency Program. He did his spine fellowship with Dr. Henry H Bohlman. He was Chief of Spine Surgery at the University of Pennsylvania.

Dr. Jason A. Seale MBA is a medical doctor and entrepreneur. He is the clinical director at the LES Clinic.

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