Facet Joint Cysts Causing Cauda Equina Compression

Ventral Lumbar Synovial Cyst Causing Cauda Equina Compression: Case Report and Literature Review

BACKGROUND

Juxtafacet spinal cysts are cystic synovial lesions that often are indistinguishable clinically or radiologically and require histopathology analysis to confirm the diagnosis. Lumbar synovial cysts usually arising from the synovium of the facet joints. They have been described posterolaterally or rarely in the posterior midline. However, we describe the first synovial cyst ventral to the dural sac.

CASE DESCRIPTION

We report a lumbar 3-4 lesion causing cauda equina compression in a 57-year-old man who presented with a 3-month history of low back pain and bilateral sciatica, intermittent urinary incontinence, and erectile dysfunction. Preoperative magnetic resonance imaging suggested prolapsed disc, after decompression, histological analysis of the fragment confirmed a synovial cyst.

CONCLUSIONS

Hitherto synovial cysts have not been reported anterior to the dural sac. We describe a lumbar ventral cystic mass with cauda equina compression that mimicked a disc prolapse due to synovial metaplasia. The patient had urgent decompression with subsequent resolution of the symptoms.

Fluoroscopic percutaneous lumbar zygapophyseal joint cyst rupture: a clinical outcome study

BACKGROUND CONTEXT

Lumbar zygapophyseal joint (Z-joint) synovial cysts can cause low back pain (LBP), spinal stenosis, and lower extremity radiculopathy. In the literature, there are several minimally invasive techniques described with mixed results. Typical recommended treatment is surgical resection of the cyst. Currently, there is little information available concerning the efficacy and outcome with treatment of Z-joint synovial cyst by percutaneous, fluoroscopic, contrast-enhanced distention, and rupture.

PURPOSE

To evaluate the therapeutic value and safety of Z-joint cyst rupture in symptomatic patients.

STUDY DESIGN/SETTING

Retrospective cohort study in an academic outpatient physiatric spine practice.

PATIENT SAMPLE

Thirty-two patients with moderate-to-severe LBP and leg pain (18 women and 14 men with an age range of 46-86 y; mean age, 66 y) with an average preprocedure symptom duration of 5 months. The patient's clinical symptoms correlated with magnetic resonance imaging studies documenting the presence of a synovial cyst at the corresponding level and side of symptoms. Patients had at least 6 months follow-up (range, 6-24).

OUTCOME MEASURES

Numerical Pain Rating Scale, Roland-Morris Disability Questionnaire, North American Spine Society four-point patient satisfaction survey, recurrence of synovial cyst requiring repeat rupture, and need for surgical intervention.

METHODS

Patients with symptomatic lumbar Z-joint synovial cyst were identified and their charts were reviewed. Patients included in the study either had symptomatic lumbar LBP or LBP with associated lower extremity radiculopathy. All patients in the study had magnetic resonance imaging's documenting Z-joint synovial cyst that corresponded with the patients' clinical symptoms. All patients received fluoroscopically guided, contrast-enhanced, percutaneous facet cyst distention and rupture followed by an intra-articular facet joint injection of 1 cc kenalog and 1 cc of 1% lidocaine. Seventeen of the patients also received a transforaminal epidural steroid injection just before facet cyst rupture. Telephone follow-up was conducted on all patients.

RESULTS

Excellent long-term (average follow-up 1 y; range, 6-24 mo) pain relief was achieved in 23 (72%) of 32 patients undergoing facet cyst rupture. Twelve patients (37.5%) had synovial cyst recurrence and 11 chose to undergo repeat rupture, which resulted in 5 patients (45%) obtaining complete relief of symptoms and 6 patients (55%) requiring surgical intervention for cyst removal. Fisher exact test demonstrated that all patients who did not have a cyst recurrence were a success and obtained complete relief of symptoms (p<.0002). Patients who underwent a repeat rupture had a 50% chance of a successful outcome. There was no statistical significance between a successful outcome and level of facet cyst rupture, the presence of spondylolisthesis, sex, age, or having a transforaminal epidural steroid injection at the time of the procedure. Wilcoxon signed-rank test demonstrated that the difference in Numerical Pain Rating Scale and Roland-Morris Disability Questionnaire scores before and after the procedure was statistically significant (p<.0001). No complications were reported.

CONCLUSIONS

Fluoroscopic percutaneous Z-joint cyst rupture appears to be a safe and effective minimally invasive treatment option. This procedure should be considered before surgical intervention.

Lumbar radiculopathy after zygapophyseal joint injection

We report a case of lumbar radiculopathy after zygapophyseal joint injections for chronic low back pain. The management of the patient and potential causes for the radiculopathy are discussed. The case acts as a reminder that the spinal nerve roots should be considered when performing intra-articular facet joint injections and demonstrates the importance of including nerve injury in the patient consent process as a rare, but significant complication.