High Rate of Revision Surgery After Limited Decompression of Lumbar Facet Cysts.

INTRODUCTION: The surgical treatment of lumbar facet cysts has long been debated. Some surgeons elect for limited decompression of such cysts while other surgeons elect for primary decompression and fusion over concerns for recurrence and instability. Previous studies have suggested the rate of revision surgery after facet cyst excision to be as low as 1%, whereas others have reported this rate to be markedly higher. In this study, we examined revision surgery rates and patient-reported outcomes and conducted a radiographic analysis to identify predictors of failure after limited decompression of lumbar facet cysts. METHODS: A retrospective review of the electronic medical records of patients treated at our institution using the Current Procedural Terminology code 63267 before January 2018 was conducted. The primary outcome measure was revision surgery at the index level for recurrence or instability or a minimum 2-year follow-up without revision surgery. Secondary outcome measures include radiographic assessments of preoperative and postoperative spondylolisthesis and patient-reported outcome measures. Using preoperative MRI studies, an analysis of facet angles at the surgical level was conducted and the presence, location, and amount of facet fluid were calculated. RESULTS: A total of 162 patients met inclusion criteria. Of these, 93 patients had a minimum 2-year follow-up. Of these, 19 had undergone a revision surgery at the index level for cyst recurrence or instability. The revision rate for this group was 20.4%. The median time to initial revision surgery was 2.2 years. The median time from index operation to last follow-up was 3.8 years. No differences were observed between the groups regarding the presence of preoperative spondylolisthesis, age, sex, body mass index, blood loss, or patient demographics. 60.2% of all procedures were done at the L4-5 level, but this level accounted for 73.7% of primary failures. A radiographic analysis showed facet angle >45° at L4-5 to be associated with risk of failure of primary decompression. The presence and absolute amount of fluid in the facets were not associated with risk of failure at the L4-5 level. DISCUSSION: Our revision rate of 20.4% is higher than what is commonly reported in the literature. The radiographic analysis shows that at the L4-5 level, a facet angle of >45° is associated with failure of primary decompression.

Routine Upright Imaging for Evaluating Degenerative Lumbar Stenosis: Incidence of Degenerative Spondylolisthesis Missed on Supine MRI.

STUDY DESIGN: A retrospective cohort. BACKGROUND: Degenerative spondylolisthesis (DS) with lumbar stenosis is a well-studied pathology and diagnosis is most commonly determined by a combination of magnetic resonance imaging (MRI) and standing radiographs. However, routine upright imaging is not universally accepted as standard in all practices. To the best of our knowledge, there has been no study investigating the incidence of missed diagnosis of DS evident only on standing lateral or dynamic radiographs when compared with sagittal alignment on MRI. OBJECTIVE: The authors hypothesize that supine MRI evaluation alone in lumbar degenerative disease will significantly underestimate the incidence of DS. Secondary hypothesis is that there will be no significant difference in detecting spondylolisthesis when comparing dynamic flexion-extension radiographs to standing lateral radiographs. METHODS: We retrospectively evaluated all patients presenting to spine clinic for degenerative lumbar conditions from July 2004 to July 2006 who had an MRI, upright lateral, and flexion-extension radiographs at our institution. The incidence of DS found on dynamic flexion-extension radiographs but not on MRI was determined. We then reviewed each and compared flexion-extension versus standing lateral views to determine whether there was any significant difference in detecting anterolisthesis. RESULTS: Of 416 patients with eligible studies, 109 were found to have DS at levels L4-L5, L5-S1, or L3-L4 based on flexion-extension radiographs. Of these, only 78 were found to have a corresponding spondylolisthesis on MRI, leaving 31/109 (28%) of DS levels undiagnosed on MRI. No additional anterolisthesis cases were detected on standing flexion-extension verses standing lateral radiographs. CONCLUSIONS: Routine standing lateral radiographs should be standard practice to identify DS, as nearly 1/3 of cases will be missed on supine MRI. This may have implications on whether or not an arthrodesis is performed on those patients requiring lumbar decompression. Flexion-extension radiographs demonstrated no added value compared with standing lateral x-rays for the purposes of diagnosing DS.

Incidence of dysphagia comparing cervical arthroplasty and ACDF.

STUDY DESIGN: Retrospective cohort from randomized prospective clinical trial. OBJECTIVE: Evaluate incidence of dysphagia between instrumented ACDF and a no-profile cervical disc arthroplasty. SUMMARY OF BACKGROUND DATA: Dysphagia is a well-known complication following anterior cervical discectomy and fusion (ACDF) and the etiology is multifactorial. One potential source for postoperative dysphagia involves the anterior profile of the implant used. Hence, a no-profile cervical disc arthroplasty could theoretically have fewer soft tissue adhesions and a lower incidence of dysphagia. The purpose of this study is to compare the incidence of dysphagia at least 1 year postoperatively following ACDF with anterior plating and a no-profile cervical disc arthroplasty. METHODS: A cohort of 87 patients meeting the inclusion criteria for the prospective, randomized, multicenter IDE trial of ProDisc-C versus ACDF were evaluated for dysphagia. Forty-five patients were randomized to receive cervical arthroplasty and 42 patients were randomized to the ACDF and plate group. The Bazaz-Yoo dysphagia questionnaire was administered in a blinded fashion after completion of at least 12 months follow-up. RESULTS: Follow-up averaged 18.2 months and included 76 (87%) of the 87 enrolled, with 38 of the original 45 in the arthroplasty group and 38 of the original 42 in the ACDF group. Six of 38 (15.8%) in the arthroplasty group versus 16 of 38 (42.1%) in the ACDF group reported ongoing dysphagia complaints. This was found to be statistically significant (P = .03). CONCLUSION: This study suggests a significantly lower rate of dysphagia with a no-profile cervical disc arthroplasty compared to instrumented ACDF for single level disc disease between C3-7. Though there are many potential etiologies, we hypothesize this is related to the lack of anterior hardware in the retropharyngeal space. Operative technique, operating time, and significant midline retraction did not seem to result in more dysphagia complaints. Future studies comparing cervical disc arthroplasty and no-profile fusion devices may help delineate the effect that anterior instrumentation profile has on postoperative dysphagia.