A 44-yr-old man presented to a spine center complaining of a 3-wk history of low-back pain, which also went into his right buttock with pain and tingling down his right lower limb posteriorly to his ankle. He denied a history of trauma, surgery, or bowel/bladder issues. Anti-inflammatory medication helped the pain somewhat. His physical examination was consistent with a right L5 radiculopathy. His lumbar magnetic resonance imaging confirmed a right L4-L5 facet cyst (Fig. 1).
The option of a spinal injection procedure was discussed, and he wanted to proceed with that. The procedure performed was a right L5 spinal nerve injection, right zygapophysial (Z-joint) injection (L4-L5 intra-articular facet), and intentional rupture of the synovial facet cyst. After the right L5 spinal nerve injection was performed, the right L4-L5 Z-joint (facet) was identified under fluoroscopy. The overlying soft tissue was anesthetized. A 23-gauge 3.5-inch spinal needle was inserted into the right Z-joint. Withdrawal revealed serosanguinous fluid. Contrast material revealed an arthrogram and then filled the cyst (Fig. 2). We filled and drained the cyst repeatedly. After several milliliters were injected, the cyst filled completely, and resistance was noted preventing further injection. The joint was intentionally overpressurized. This increased his pain significantly in his back and right lower limb. It was his typical pain, but more severe. Then, the resistance dropped precipitously and his pain eased. This was presumably when the cyst ruptured. He felt fine in the recovery area with virtually no pain. He received postprocedural posture and home exercise instruction by a physical therapist. In follow-up, he remained virtually asymptomatic and quite pleased with this treatment. He had no numbness or tingling, and his pain level remained 0 of 10.
The Z-joint is a synovial joint that has also been known to produce cysts. Those cysts are thought to be a result of a degenerative cascade but may result in low back pain. Cysts encroach the neuroforamen and cause spinal nerve irritation and radiculopathy. L4-L5 is both the most mobile segment in the spine and the most common location for cysts.1 This case illustrates that facet joint cysts can be safely and effectively ruptured percutaneously under fluoroscopic guidance.
1. Doyle A, Merrilees M: Synovial cysts of the lumbar facet joints in a symptomatic population: Prevalence on magnetic resonance imaging. Spine