Synovial cysts commonly may arise throughout the body. Synovial cysts are sometimes called ganglion cysts. Synovial cysts that arise in the spinal canal can cause severe back and leg pain. They are usually small painful cysts located in the epidural space inside the spinal canal. They arise from degenerated “worn out” spinal facet joints. They have a fibrous wall and are filled with thick mucus fluid similar to synovial cysts found in other areas of the body.
As synovial cysts grow they cause pressure or “pinch” near by nerves producing pain. They can also produce numbness, tingling and weakness. They are usually slow growing but sometimes form rapidly.
Treatment of synovial cysts include: observation, epidural steroid injection, intra-cyst steroid injection to rupture the cyst and surgery. Surgery usually requires large incision with significant bone and ligament removal to enter the spinal canal and remove the cyst. Since the degenerated facet joint is the source of the cyst it is possible for the synovial cyst to recur. Future resections may entail partial or complete removal of the facet joint and lumbar fusion.
Today many of these synovial cysts can be removed through the spinal foramen with little to no bone removal with the spinal endoscope. Endoscope is a video camera connected to a high definition scope the size of a pen which can be placed into the spine to the synovial cyst for direct visualized removal. Patients often feel immediate pain relief and are able to return back to normal activity much faster then with traditional open spinal surgery.