Home › Blog › Leg Feels Disconnected? It May Be Your SI Joint

I always love hearing how patients describe what’s going on in their body. This last week, a patient with SI joint instability described her problem as her “leg feels disconnected.” This is such an accurate description that I thought it was worth exploring in a blog.

The SI (Sacroiliac) Joint

The SI joint is where the tailbone (sacrum) and the back of the hip meet. It’s part of a three-joint system that makes up the pelvic ring. There are two SI joints in the back and one joint in the front (symphysis pubis). All three of these joints work in concert to allow forces to travel from the leg to the spine. The joints are surrounded by thick and strong ligaments.

How the Leg Can Feel Disconnected from the Hip

So how can the patient report that her leg feels disconnected? The leg’s physical connection to the rest of the body is through the hip joint. As you can see to the right, the hip joint connects to the pelvis. If both an SI joint and the joint in the front (symphysis pubis) are lax (unstable) due to damaged ligaments, then the only physical connection of the leg to the body is also loose. Hence, the leg will feel disconnected from the rest of the body.

How Can This Be Fixed?

This patient had been successfully treated 4–5 years ago by using the growth factors derived from her platelets plus a proliferant to help these ligaments tighten. She went from having to wear an SI belt at all times to not having to wear one during normal activities. In fact, the only time she wears her SI belt now is when she’s skiing. She’s now wanting to take the next step and tighten the ligaments further so she can further increase her activities and try to get back to running.

While many of these patients end up with temporary relief from a steroid injection into the SI joint, this does nothing to address the instability causing the problem. Also, most physicians don’t understand that the symphysis pubis joint in the front of the pelvis is as important to treat as the SI joint. Hence, many doctors who offer prolotherapy (ligament injections) don’t treat that area. In fact, this patient was offered that several years ago but demurred. She’s now ready to take that step so we can get more of the pelvic-ring instability under control. So this time, we’ll not only inject the SI joint but use fluoroscopy to target the symphysis pubis as well.

The upshot? I love to hear how patients conceptualize their problem. The famous physician Sir William Osler once said that if you listen to the patient long enough, they’ll tell you exactly what’s wrong with them. In this case, the good doctor was right!

Chris Centeno, MD is a specialist in regenerative medicine and the new field of Interventional Orthopedics. Centeno pioneered orthopedic stem cell procedures in 2005 and is responsible for a large amount of the published research on stem cell use for orthopedic applications. View Profile