Hemorrhagic synovial cyst: the possible role of initial trauma and subsequent microtrauma in its pathogenesis: case report

Intraspinal synovial cysts are uncommon causes of back and radicular leg pain. Usually associated with degenerative spinal disease, these juxtafacet cysts are usually located in the lumbar spine and may rarely undergo intracystic hemorrhage. The pathogenesis of these cysts are unclear, and risk factors that may contribute to hemorrhagic complications are largely unknown. A 68-year-old man presented to the clinic 4 months after a fall on ice with persistent back pain and lumbar radiculopathy. A week after the initial clinic consultation, the patient presented to the emergency room with increased pain and worsening weakness in the left foot. An emergent magnetic resonance image showed thecal sac compression secondary to a large, juxtafacet cyst that was hyperintense on T1-weighted and hypointense on T2-weighted images. Lumbar decompressive laminectomies were performed at L3 and L4 with cyst removal and stabilization. We present the eighth reported case of a hemorrhagic juxtafacet cyst secondary to physical trauma, the second in which the patient's symptoms acutely worsened several months after the initial insult without new trauma. We also present summary statistics of the 31 cases of hemorrhagic juxtafacet cysts reported in the literature and propose a putative mechanism that may account for the development and progression of symptoms in some patients.