iFuse Implant System®
Minimally Invasive Sacroiliac Joint Surgery
Sacroiliac joint fixation is a surgical procedure in which the joint is fixed to its intended position and weightbearing function. With the iFuse Implant System, this is accomplished by inserting three or four small titanium implants across the sacroiliac joint to fix and stabilize it.
- Less invasive than traditional open surgery with no extensive soft tissue stripping
- Straightforward minimally invasive surgical (MIS) approach
- Implant profile and design minimizes rotation and micromotion
- Rigid titanium implants provide immediate post-op SI joint stability
- Porous plasma spray coating with irregular surface designed to support stable bone fixation/fusion
- Larger implant surface area designed to maximize post-surgical weight bearing capacity
- Biomechanically rigorous implant designed specifically to stabilize the heavily loaded SI joint
Frequently Asked Questions
Low back pain is a common symptom that affects many people during their lifetime. For some, low back pain can be an acute, short-term problem. Others experience chronic, long-term symptoms. There are many structures in the lower back and pelvic area that can cause pain. Most commonly, people think of a slipped disc or back injury as a cause of low back pain. Occasionally, hip problems can be confused with low back conditions. In fact, there are many causes of back pain, including arthritis of the back, osteoporosis, and a poorly aligned spine. Issues with the sacroiliac joint can be a significant contributor to pain in the lower back, pelvic region, buttocks, or legs.
The sacroiliac joint is located in the pelvis, linking the iliac bone (pelvis) to the sacrum (lowest part of the spine above the tailbone).
The function of the SI joint is to transfer weight and forces due to movement from your upper body through the pelvis to your legs and vice versa. Your pelvis acts as a central base through which large forces are transferred and dissipated. The primary role of the SI joint is to provide stability for the pelvis, and to bear the load of the upper body.
Potential causes of SI joint problems include degenerative disease, history of trauma, pregnancy/childbirth, and other unknown reasons. The SI joint may be disrupted due to lack of joint continuity (injury, traumatic event or repetitive trauma to the joint) or may suffer from sacroiliitis (swelling) resulting from a variety of causes.
The SI joint is a type of joint known as a synovial joint. This type of joint has free nerve endings that can cause chronic pain if the joint degenerates or does not move properly due to swelling and/or disruption. Problems with the SI joint have been long known to cause pain in the lower back and buttocks. Like any other joint in the body, the SI joint can become swollen or injured. When this happens, people can feel pain in their back or buttocks, especially with lifting, running or even walking.
It is commonly reported in clinical literature that up to 33% of all low back pain is caused by the SI joint.
Many people have low back pain associated with the SI joint that begins spontaneously. However; in just as many reported cases, SI joint pathology can be related to a specific event, often an injury. It is difficult to directly relate any specific functioning difficulty (including walking, sitting, standing, sleeping on the affected side, job activity, bowel movements, cough, sneeze, etc.) to the SI joint as a source of pain. One key indication is the specific location of the pain in the lowest back and buttock region.
Injury from accidents, including falling, is a predisposing factor for SI joint pain. Women may be at increased risk for SI joint problems because of their broader pelvises, the greater curve of their necks, and shorter limb lengths. In addition, pregnancy often leads to stretching of the pelvis, specifically in the sacroiliac ligaments.
If you have trouble sleeping comfortably, or frequently experience your knee giving way, pain in certain lying or bending positions, or tenderness in your buttocks, you may have SI joint disruption or dysfunction. Speak to your doctor about your symptoms.
Doctors do not always look for the SI joint as a source of lower back issues, although many articles have been written about it. Your back issues may have been previously diagnosed as related to the lumbar spine. However, if the source of your pain is difficult to assess, and/or image studies do not indicate a spine problem, this may indicate that the source of your problems is other than the lumbar spinal region.
The most important information you can give your doctor is the exact location of your pain and level of your functionality. Try to notice when the pain occurs and how intensely you feel it in various locations, including your low back, buttocks, and legs. Also, be sure to tell your doctor about any previous injury that may have either directly affected your pelvis, or caused you to walk asymmetrically, or may relate in any way to your functionality. Your doctor will consider all the information you provide, including any history of injury, location of your pain, and problems standing or sleeping. Your doctor will also give you a physical examination. You may be asked to stand or move in different positions and point to where you feel pain. Your doctor may manipulate your joints or feel for tenderness over your SI joint. All of these can help establish a diagnosis. In addition, X-rays, a CT scan, or MRI may be helpful in diagnosis. It is also important to remember that more than one condition (like a disc or hip problem) can co-exist with SI joint problems and your doctor will need to check for other factors that may be causing your symptoms. The most reliable method to accurately determine the cause of SI joint pain is to inject the SI joint with painkillers. Your doctor will deliver the injection with either fluoroscopic guidance or CT guidance to ensure that the needle is accurately placed in the sacroiliac joint. If, following the injection, your pain is decreased a significant amount, then it can be concluded that the SI joint is either the source, or a major contributor, to your low back pain. If the level of pain does not change after the injection, the SI joint is not the primary cause.
It is not always easy to diagnose SI joint issues. Sometimes your physical findings may indicate a sacroiliac joint problem, but issues may also be seen in your lumbar spine. Your doctor may discuss the difficulty of making a correct diagnosis in the presence of multiple abnormalities. To confirm the SI joint as the source of your symptoms, and specifically pain, injections are invaluable. Provocation tests are also helpful for localizing the symptom source.
There are several options for treating the sacroiliac joint. Some people respond to physical therapy, chiropractic manipulations, and exercises. Others require more interventional treatments including various oral medications, therapeutic injections, or radio frequency treatments. Usually symptom improvement using these therapies is temporary and treatments may need to be performed repeatedly to treat recurrent symptoms. Another option is a surgical procedure known as SI joint arthrodesis or SI joint fixation/fusion. This procedure stabilizes and fixes the joint, which is done to minimize joint motion.
Traditional SI joint fixation/fusion involves open surgery that may last up to several hours. Open surgery typically includes a significant incision to access the joint, removal of cortical tissue from the joint and use of bone grafts from another part of your body to help fuse the joint. Patients typically require a several day hospital stay. The minimally invasive surgical (MIS) iFuse Implant System® is now available. The MIS procedure requires a smaller incision and uses a guide pin to place the titanium implants across the SI joint. These small implants are designed to fix the SI joint and allow stable healing through significantly reduced micromotion. Almost all iFuse cases use three or four implants. A minimum of two 7.0mm implants must be used.
The iFuse Implant System is intended to fix the joint for treating SI joint conditions. These may include injuries or chronic conditions. The procedure has been used successfully on patients who were injured in a fall, had back pain after pregnancy, or job-related repetitive stress injuries.
Once the source of your symptoms has been diagnosed as SI joint in origin, your surgeon will discuss the iFuse Implant System with you. You may be an iFuse surgery candidate if your low back pain is predominantly below your L5 vertebra, your doctor does not find any neurological problems, and is able to determine through maneuvering your joint that your pain originates in the sacroiliac joint. To confirm your diagnosis, your doctor will administer a CT guided injection to your SI joint and verify that you experience significant pain relief from it. Some doctors may repeat the injection to be sure.
The iFuse Implants are small triangularshaped titanium devices about the size of your little finger. Titanium is a very strong but lightweight material chosen for its high level of biocompatibility.
The iFuse Implants have triangular cross-sections to prevent them from rotating once they have been implanted. They are also coated with a titanium plasma spray that creates a rough latticed structure on the surface of the implants. This helps to better secure the iFuse implants in the bone. The stiffness of the iFuse holds the joint in place.
The iFuse Implant System is used in a surgical procedure that is performed in an operating room with either general or spinal anesthesia. You will be lying face down while your surgeon uses the specially designed system to guide the instruments that prepare the bone and insert the implants. The surgical technique, iFuse implant, and supporting instrumentation are designed to offer maximum protection to your tissues and minimize soft tissue exposure. The entire procedure is performed through a small incision (approximately two inches), along the side of your buttock. During the procedure, fluoroscopy using an X-ray machine provides your surgeon with live imaging to ensure exact placement of the implants. Typically, three to four implants are placed, depending on your size.
You will need to use either crutches or a walker for up to 12 weeks. You will not be allowed to engage in weight-bearing activities on the fused side for 6 weeks. You should not travel by air for a minimum of 2 weeks after an iFuse surgery. This limitation on air travel is strictly a precaution, and has to do with decreasing what is already a low risk of clots forming in the veins of your legs. It is also recommended that you see your surgeon for a post-operative visit some where between 1 and 2 weeks following surgery. However each surgeon may have specific recommendations as patient situations may vary. If your doctor agrees, you can start partial weight-bearing activities for another 6 weeks. At 12 weeks, you will come back for more X-rays and, barring any complications and your doctor’s okay, you may resume full weight-bearing activities.
Your doctor will advise you on resuming your daily living activities as your symptoms allow. Depending on your occupation, you may be able to return to work at this time. You will need to have additional X-rays taken at 6 months and later at 1 year in order to assess your progress.
No, the iFuse Implants are not anticipated to affect the ability to have other surgeries.
The iFuse Implant System® may be safely used in patients with previous orthopedic surgeries and spinal implants. SI joint problems may coexist with lumbar spine or hip conditions. Sacroiliac problems may appear after lumbar spine surgery or hip replacements. The iFuse system can be used after either lumbar or hip surgeries, and even after both. Your doctor will determine whether your health, including any impact from previous surgeries, influences your being a candidate for MIS SI joint fixation/fusion surgery.
Major complications from this procedure are rare, but like any surgery you may undergo, there are always some risks. Postoperative bruising and local swelling are part of the expected surgical recovery. One example of a major complication that can occur is infection. Infection can happen with any interventional procedure. This is why antibiotics are typically used both before and after surgery. This greatly lessens the risk of infection.