Answer: Traction, a Screw and MiMedx | Orthopedics This Week

Answer: Traction, a Screw and MiMedx

Image created by RRY Publications, LLC. Source: MiMedx

Question: What are three fascinating new technologies or companies in orthopedics?

New product ideas and companies come across our collective desks at OTW every week. Three recent innovations in particular stand out. They are a traction system, a pedicle screw system (?!), and a tiny but rapidly growing biomaterials company in Georgia named MiMedx.

We’ll start with the blast from the past—an updated traction system for spine patients called the Standup Traction System (STS). Jud Carlson, an old friend of ours and one of the best known and regarded medical technology entrepreneurs in America, emailed us recently about the STS. The inventor is David Perrego, a chronic, low back pain patient of Dr. David A. Petersen in Clearwater, Florida. Perrego had run out of treatment options and with help from both Dr. Peterson and Dr. Al Gadomski developed the STS. In total, about 500 patients have been treated with this new upright traction system.

Dr. Peterson tested the STS on 57 of his own patients who presented with a wide variety of back problems ranging from mechanical low back pain to failed back syndrome to radiculopathy secondary to HNP to spondylolisthesis, gross spinal instability and multi-level degenerative disc disease.

The Standup Traction System is FDA approved, has a reimbursement code in place for clinical use of lumbar traction and Cigna pays for home lumbar traction.

Vertical traction is not a new idea. The Sister Kenny Institute showed that vertical lumbar traction was more effective than horizontal traction in the 1980s using an electromechanical bed that could be moved from horizontal to vertical. They tested vertical traction on 30 patients diagnosed with low back pain resulting from lumbar disc herniation, disc degeneration and segmental instability. In the Sister Kenny study, 30 healthy individuals were also given the same traction procedure. According to the Sister Kenny study report, patients who’d been treated with vertical traction achieved disc distraction that was approximately 3 mm which compares to 0.89mm for horizontal traction, reported in other studies in each intervertebral space in both groups.

Traction is a method for distracting the spine and decompressing the intervertebral disc by applying a drawing or pulling force in a highly precise manner.

Unlike traditional horizontal traction systems, vertical systems like the STS use the patient’s own body weight as the traction force and then use a fulcrum pad to direct the force of the body weight to specific spinal segments. Dr. Petersen treated a broad range of his patients three times per week for three weeks.

In Dr. Petersen’s study, the STS mechanically reduced inflammation for 88% of the patients undergoing treatment regardless of the cause of their back pain.

Dr. Petersen accepted virtually all comers to try traction in his study. The patients came from every walk of life, made no changes in their current lifestyle, diet, exercise programs, medication profiles or activity levels during the study period. Dr. Peterson accepted no payment for the study but he is a non-majority shareholder in the company that makes the traction system.

Each patient was treated in the STS with three sets of traction. The doctor placed the fulcrum pad at the area most consistent with the patient’s diagnosis. For example, a patient with pain at L4-5 would have the fulcrum pad placed at the level just above the L4-5 level to ensure that the force was being seen at the level of the patient’s problem. The traction continued for 30-90 seconds per set.

Since 65% of the patient’s body weight is focused at a specific spinal level, it is much more force than is generally seen during horizontal traction. One of the advantages of this approach is that the patients have total control over the amount of body weight that they apply.  They can go for full suspension, which applies 65%, or partial suspension.  They can also choose flexion or extension which adjusts the direction of the force.

The patients in the study ranged in age from under 20 years to over 71 years. As the following table illustrates, the range of complaints is very broad.

# of Patients
Treated With VTS

Primary Diagnosis


     DDD Multi-Level


     Low Back Pain


     Herniated Nucleus Pulpous


     Prior Surgery






     Failed Back Syndrome


     Gross Instability

Source: Dr. David Peterson

The results of using this new form of traction were impressive:

  • 88% of the patients reported both subjective and objective pain improvement.

  • 78% of the patients for whom surgery was their only presumed option had objective pain improvement.

  • 62% of the patients with radicular symptoms improved regardless of diagnostics or symptom duration.

For more information, drop Jud Carlson an email at: or call 561-756-2660.

The Expanding Orthopedics Pedicle Screw

A small Israeli start-up company, Expanding Orthopedics Inc. (EOI), has taken a technology developed by Israeli-based orthopedic surgeon Dr. Mark M. Levy and created an innovative new type of bone screw. Its first application is spine surgery, but this technology can be used in plenty of other places. With ten issued patents, this is a serious new twist on a well-established implant—the venerable bone screw.

How can the bone screw be improved? Levy’s invention does it two ways—better bone fixation but without burning any bridges and no need to use bone cement to hold the screw in place.

The design is terrifically clever. The key is the built-in operating mechanism. It allows the surgeon to open and close the wings of the screw. To use engineer-speak: the unique expansion mechanism allows for both deployment (expansion) for fixation and an active un-deployment for removal or repositioning of the screw.

The screw system is called “XPED” and it includes expandable screws, standard screws and instrumentation. XPED is starting to be used by a rapidly growing number of surgeons in Europe and Israel (it is CE marked). Initial reviews from surgeons who’ve used it in the EU are excellent with the longest follow up of about a year.

“Initial anchoring and long-term fixation of the pedicle screw within the vertebral body are crucial for successful spinal fusion”, said Ronald Rissel, M.D., Head of Spine Center, Stauferklinikum, Mutlangen, Germany. “A growing number of our patients undergoing spine fusion surgery suffer from an impaired bone condition as a result of chronic diseases, an unhealthy lifestyle and aging spine. In these patients, standard pedicle screws are sub-optimal, leading to a higher risk of screw loosening and resulting in a high re-operation rate. I expect the XPED expandable screw’s innovative design to provide enhanced anchoring and potentially improve patient outcome.”

Not only is the screw easy to place and easy to retract if necessary, it also holds extraordinarily well. The attached chart shows how much force is required to pull the XPED screw out versus a standard pedicle screw. No cement required to achieve this kind of pull out strength.

EOI’s CEO, Mr. Ofer Bokobza said: “The XPED Pedicle Screw System is a complete spinal implant system which defines a new standard of fixation with its enhanced anchoring capability. It allows the surgeons the flexibility to select the optimal fixation solution by indication and bone condition. The XPED’s 4-wing screw is designed to increases the contact area with the bone, thus facilitating improved, immediate bone anchoring. Additionally, it allows for natural bone in-growth process which provides secondary natural fixation. The XPED Pedicle Screw System is CE marked and commercially available across Europe.”

The system is not yet FDA cleared.

EOI announced recently that it had started a post-market, prospective study in Europe for the XPED system. Bokobza expects to enroll up to 50 patients in multiple centers. He also plans to follow the patients for up to 24 months post implantation using quality-of-life questionnaires and radiographic assessments. The renowned spine team of the Stauferklinikum in Germany is leading the study, with other centers due to join in the coming months.

Email Ofer Bokobza at for more information.

MiMedx Group, Inc.

Parker H. “Pete” Petit built two hugely successful companies from scratch—Healthdyne, Inc. and Matria Healthcare, Inc. He would eventually sell Matria Healthcare in a transaction valued over $1.2 billion and “retire.” In “retirement” Petit served as a director of Intelligent Systems Corp. and Logility, Inc. He was elected to the Georgia Technology Hall of Fame and funded a professional chair for Engineering in Medicine at Georgia Tech. He endowed the Petit Institute for Bioengineering and Biosciences at Georgia Tech and took numerous high profile board positions. But for “Pete” Petit, this wasn’t even living life at cruising speed.

So at a mere 69 years of age Petit came roaring out of retirement in 2009 at the request of a mutual friend of ours, Steve Gorlin, to take over a small struggling biologics company in Atlanta named MiMedx. Petit’s first move was to acquire Surgical Biologics, Inc., which is run by the immensely talented John Daniel and Randall Spencer.

MiMedx, whose stock trades under the symbol MDXG, announced early this year that it had raised $5 million and then a couple weeks back announced a key partnership with Affirmative Solutions—a national distributor of spine, biologic and other medical products to the U.S. Veterans Administration and the Department of Defense.

What makes MiMedx so special?

Besides “Pete” Petit, this spit fire of a company has one of the most interesting biomaterial portfolios of ANY company in orthopedics. Some of the larger firms should take notice—it’s got four power house product platform technologies in it.

CollaFix: This is a remarkable collagen technology which mimics in composition, structure and mechanical properties the musculoskeletal system. The technology is based on collagen fibers about the size of human hair which are fabricated in continuous lengths of spooled fibers. These are cross-linked which makes them incredibly strong, biocompatible and long lived after implantation yet the material remains resorbable and biocompatible. In a sense, CollaFix reminds us of a collagen-like Gore-Tex or GraftJacket.

HydroFix: HydroFix technology originated at the Georgia Institute of Technology in Atlanta, Georgia. In the late 1990's, several graduate students and Professor David Ku, M.D., Ph.D. discovered a method for producing a very durable, strong but also easily modifiable polymer hydrogel into virtually any shape. The material mimics the properties of soft tissue and it can be manufactured with material properties that are tailored to just about any orthopedic or vascular implant application. In specific formulations the material may prohibit cellular attachment and tissue in-growth.

AmnioFix: Our personal favorite, this is a biologic amniotic membrane which has been processed through Surgical Biologic’s proprietary Purion process and which combines cleaning, dehydration and sterilization to produce a safe, technically sterilized allograft utilized for soft tissue surgical repair and healing in various ophthalmic, orthopedic, spinal surgery, dental and sports medicine applications.

EpiFix: EpiFix, the branded tissue produced by MiMedx and processed through Purion, is a biologic implant specifically processed from amniotic tissue to offer a wide variety of wound healing and wound care options.

For more information about MiMedx please contact Pete Petit at 866-477-4219.


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