A challenge diagnosis of lumbar synovial facet cyst. A case report

Synovial cysts occur more frequently in the lumbar spine, especially at L4-5 level. Traditional open surgical management with posterolateral arthrodesis is the currently recommended treatment.

This is a 64-year-old woman with no prior pathological history. Initial clinical and radiological assessment concluded that there was advanced right coxarthrosis with a degenerative lumbar spine. The patient therefore had a total hip arthroplasty secondarily presented an intermittent neurogenic claudication without sphincter disorders. The MRI concluded at a compressive synovial facet cyst at the L4-L5 level. The patient underwent surgical treatment. At two years postoperatively, the walking distance was significantly improved while maintaining moderate lower back pain.

The diagnosis of synovial facet cysts of spine is a challenge that depends heavily on history, physical examination, and MRI. MRI will demonstrate not only the nature of the cystic lesion, but also its relationship to the root, the cord or the thecal sac. The L4-L5 level of the lumbar spine is the most common location of the synovial cyst of the facet joints. As in our case, surgical treatment combining posterolateral arthrodesis is currently recommended for these types of lesions. Surgical treatment, as in our case, is sometimes delayed when this pathology is associated with advanced osteoarthritis of the hips.

Improved imaging capabilities such as magnetic resonance imaging (MRI) have resulted in increased reporting, diagnostic yield and treatment of spinal synovial cysts. Surgical treatment combining posterolateral arthrodesis is the treatment for this lesion.