SI-BONE, Inc.Spine’s innovation rate may no longer be the juggernaut it once was. Independent auditing/actuarial firms (looking at you Milliman) may be trying to re-draw the boundaries of spine care. But none of that seems to be affecting a small company located just off the Junipero Serra Freeway at Winchester Blvd. in San Jose, California. The three-year-old firm appears to have uncovered an overlooked corner of the spinal implant market which, in size, maybe as large as 20% of all spine surgeries! Perhaps even as large as the market for vertebral compression fracture treatment.
SI-BONE and the SI Joint
The new company , SI-BONE, Inc. is being directed by a few experienced medical device hands and one veteran of the Silicon Valley electronics world. Jeffrey Dunn, formerly of INBONE, Active Decisions and before that Velogic (an internet performance company) is president and CEO. None other than Mr. Kyphon himself, Mark Reiley, M.D., is SI-BONE’s founder. In the supporting cast are Garret Mauldin, from INBONE, Jeffrey Polack, from Matrix Medica and St. Jude Medical and Kevin Shaw from St. Francis Medical and Medtronic.
SI-Bone’s iFuse Implant SystemDr. Reiley, aka: “Kyphon1” (as he calls himself in his emails), invented SI-BONE’s iFuse implant system to treat sacroiliac pain (see image to the right).
Sacroiliac pain? Isn’t that somewhere south of L5? The sacroiliac joint (SI) is a joint complete with synovial fluid and strong ligaments. It’s below L5 but above the remaining vestige of the human tail—er coccyx. And there are two of them. Two sacroiliac joints—left and right. Both are weight bearing and together they function to support the spine although, as time progresses they may not necessarily match—which is to say that as we age the characteristics of the sacroiliac joint change.
Because of effects of walking, jumping, skiing, skate boarding, horizontal tangoing, etc., the SI joint’s surfaces evolve from flat or planar early in life to distinct angular orientations (losing their planar or flat topography).
The SI joints can also develop an elevated ridge along the ilial surface and a depression along the sacral surface. The ridge and corresponding depression, along with the very strong ligaments, increase the sacroiliac joints’ stability and makes dislocations very rare.
Like most lower extremity joints, one of the SI joints’ functions is shock absorption (depending on the amount of available motion at the sacroiliac joint) for the spine, along with the job of torque conversion allowing the transverse rotations that take place in the lower extremity to be transmitted up the spine.
The SI joint, like all lower extremity joints, provides a “self-locking” mechanism (where the joint occupies or attains its most congruent position, also called the close pack position) that helps with stability during the push-off phase of walking. The joint locks (or rather becomes close packed) on one side as weight is transferred from one leg to the other, and through the pelvis the body weight is transmitted from the sacrum to the hip bone.
Like all joints, the SI is subject to degenerative processes and can become inflamed. When it does, the patient will report, typically, unilateral low back pain. Or buttock or thigh pain.
Prevalence of SI Abnormalities
What is the prevalence of sacroiliac joint inflammation?
Drs. O’Shea, Boyle, Salonen, Ammendolia, Peterson, Hsu and Inman tackled that precise question and published their answers March 30, 2010 in the American College of Rheumatology’s Journal of Arthritis Care and Research.
The investigators studied 315 patients (173 men, 142 women). One hundred patients (31.7%) had signs of SI joint abnormalities; 75 (23.8%) had signs of joint degeneration; and 25 (7.9%) had signs of joint inflammation. The investigators found that the incidence of degenerative SI disease was predominantly found in women (68%), whereas SI joint inflammation was found by the investigators predominantly in men (63%).
In women, the investigators found that there was no correlation between degenerative SI joint abnormalities and degenerative changes in the lumbar spine. Of the clinical descriptors evaluated, none were associated with the radiographic findings with the exception of buttock pain, which was associated with inflammatory sacroiliitis. Interestingly enough, the researchers found that neither being overweight nor pregnancy history was associated with degenerative changes in the SI joint.
According to the National Institute of Neurological Disorders and Stroke (a division of NIH), “Americans spend at least $50 billion each year on low back pain.” Low back pain is the most common cause of job-related disability and a leading contributor to missed work. Several leading orthopedic publications over the last few years have stated that anywhere from 15-25% of all low back pain is SI joint in origin.
According to a study by Bernard and Kirkaldy-Willis, over 22% of individuals who presented with lower back pain actually had sacroiliac (SI) joint pain. A wealth of published clinical literature indicates that SI joint pain frequently mimics discogenic or radicular low back pain, resulting in many patients receiving lumbar fusion instead of SI joint fixation/fusion.
A Unique Company
Frankly, this is the first time we at OTW have found a company that was specifically targeting SI joint pain and the diagnostics and implants to treat it.
Said CEO Jeffrey Dunn: “Treating SI joint degeneration and pain is an underserved need that could represent millions of patients. Even surgeons are not generally aware of either the diagnosis or treatment for SI disease. I was having dinner with a surgeon early in the development of this company and he said to me ‘Jeff, I don’t know what the hell you’re talking about. I don’t look below L5 and if I looked there I wouldn’t know how to diagnose it and if I found it I wouldn’t know what to do with it!’”
Continued Dunn, “So we are squarely focused on education. This company’s only about two things—education and clinical. “
SI-BONE, Inc. was founded in April 2008 as a spin out when Wright Medical bought Reiley’s INBONE Technologies. INBONE, with the ENDO-FUSE Intra-Osseos Fusion System, was founded by Mark Reiley, the inventor of kyphoplasty and the vertebral fracture treatment.
Using the ENDO-FUSE titanium technology (which has been used in more than 1, 000 patients), Dr. Reiley and the SI-BONE team developed kind of intramedullary implant to treat SI joint pain and instability. The implant is positioned in the space via a 1.5 inch incision and is significantly less invasive than the traditional sacroiliac (SI) joint fixation/fusion surgery.
Since founding in 2008 SI-BONE has grown rapidly. Said Dunn; “At this stage I can only say that we’re having a hell of lot fun. The team is very energized. We have about 50 people. A year ago we had five. Where do we want to take the company? Everyone in the company wants to work at this for a while. We’re helping patients. I mean it’s spectacular.”
Education and Patient Selection
But Dunn has no illusions about the difficulty of the task. “The key here is just like Kyphon. It’s education. Our sales force comes from such firms as Kyphon, NuVasive, Trans1 or St. Francis. They understand how hard the work is. That you have to do the early work. The education work. The diagnostic work. This isn’t about the surgery…this is a Mark Reiley invention [and] I can tell you that it works…it’s about can we educate 100, 000 medical professionals?”
And patient selection.
“I really think one of the biggest problems in spine is diagnosis, ” said Dunn. “With our approach when you do that injection into the SI joint, the diagnosis is pretty conclusive. That gives me confidence that our surgeons, if trained well, will start with the best patient selection.
This company is all about education. We start with the anatomy, then we go to diagnosis, we show how to do an injection, we show them how to do the provocative test. At the end of the day, patient satisfaction from spine surgery can’t be at 60%. Surgeons have to select the right patients and then we’ll all be happy—the patient, the hospital, the insurance company and the surgeon.”
SI-BONE is just three years old. But the enthusiasm (see related video) at this young company is palpable. We’ve got our eye on SI-BONE and we fully expect to be hearing and reporting big things as the years unfold.
