Percutaneous Rupture of Zygapophyseal Joint Synovial Cysts: A Prospective Assessment of Nonsurgical Management

Abstract

Background: Although lumbar zygapophyseal joint synovial cysts are fairly well recognized, they are an uncommon cause of lumbosacral radicular pain. Nonoperative treatments include percutaneous aspiration of the cysts under computed tomography or fluoroscopic guidance with a subsequent corticosteroid injection. However, there are mixed results in terms of long-term outcomes and cyst reoccurrence. This study prospectively evaluates percutaneous ruptures of zygapophyseal joint (Z-joint) synovial cysts for the treatment of lumbosacral radicular pain.

Objectives: Primary: To determine whether percutaneous rupture of symptomatic Z-joint synovial cysts leads to sustained improvements in radicular pain and function. Secondary: To assess the rates of cyst recurrence and progression to surgical intervention following percutaneous rupture of symptomatic Z-joint synovial cysts.

Design: Prospective cohort study.

Setting: Outpatient academic spine practice.

Participants: Adults with primary radicular pain due to a facet synovial cyst.

Methods: Participants underwent fluoroscopically guided percutaneous Z-joint synovial cyst ruptures under standard-of-care practice. Data on pain, physical function, satisfaction, and progression to surgery were collected at 2 weeks, 6 weeks, 3 months, 6 months, and 1 year after rupture. An intention-to-treat analysis was used for assessment of patient-reported outcome measures.

Main outcome measures: The Numerical Rating Scale, Oswestry Disability Index, and modified North American Spine Society questionnaires were used to measure pain, function, and satisfaction with the procedure, respectively.

Results: Thirty-five participants were included in the study, and data were analyzed by an independent researcher. Statistically significant changes in Oswestry Disability Index were reported at 2 weeks, 3 months, and 1 year postintervention (P = .034, .040, and .039, respectively). A statistically and clinically significant relief of current pain was reported at 2 weeks (P = .025) and 6 weeks (P = .014) with respect to baseline. Patients showed significant improvements for best pain at 6 weeks with respect to baseline (P = .031). Patients' worst pain showed the greatest amount of improvement with clinically meaningful changes at all time points compared with baseline. Patient-reported satisfaction was found nearly 70% of the time at all time points. Forty percent (14/35) of participants required repeat cyst rupture, and 31% (11/35) required surgical interventions.

Conclusions: There were statistically and clinically significant improvements in pain and function after percutaneous rupture of Z-joint synovial cysts. In addition, the outcomes support previous retrospective studies indicating that approximately 40% of patients will need surgery. This study provides further research to determine the utility of this procedure and to precisely define a subset of ideal candidates.

Level of evidence: Level II.