Treatment of Juxtafacet Cyst of the Lumbar Spine by Dynamic Interspinous Stabilization - a Case Report

Juxtafacet cysts of the lumbar spine cause low back pain and radicular leg pain in 1-10% of cases. Spinal instability appears to be the main causative factor in the etiopathogenesis of synovial cysts. None of the literature to date mentions referral to dynamic stabilization for treatment without surgical cyst excision. In this case report, we describe dynamic interspinous implantation for treatment of juxtafacet cyst for the first time. The aim of this report is to introduce interspinous implant insertion, quite a novel approach to surgical treatment that shifts treatment emphasis to achievement of spine stability through a percutaneous, minimally invasive technique. The patient, a 56-year-old male, presented with low back pain and right L5 nerve-root pain. MRI revealed degenerative spondylolisthesis (2-3 mm) and stenosis at segment L3/4 and a right L4/5 juxtafacet cyst. Six months later, the cyst had increased in size to 7x5x13 mm and despite intensive conservative treatment, the patient's symptoms became worse. We performed percutaneous, minimally invasive insertion of In-Space (Synthes, USA) interspinous implants from a lateral approach to the L3/4 and L4/5 level. Postoperatively and at 10-month follow-up, the patient reported complete resolution of radicular symptoms without complications. MRI of the lumbar spine nine months after surgery revealed complete resorption of the juxtafacet cyst. Obvious surgical removal of facet cysts makes possible direct decompression of the nerve root, but the cause of development of the cyst (facet degeneration and instability) remains without treatment. Interspinous implant is intended to stop the segmental extension and protect the posterior elements (mainly) by reducing stress on the facet joints. This is the mechanism that allows resorption of the juxtafacet cyst and relief of symptoms. The percutaneous, minimally invasive insertion of an In-Space interspinous implant is a considerate and safe method of dynamic stabilization, very well tolerated by the patient.