Krauss, William

Study design: Cohort study. Objective: This study aimed to evaluate influence of facet cysts on outcomes in patients undergoing lumbar decompression, and the influence of spinal fusion in patients undergoing decompression for facet cysts. Summary of Background Data: The impact of facet cysts on outcomes following lumbar spine surgery for degenerative spine disease remains unclear. Methods: Our multicenter institutional Neurosurgery Enterprise Registry was queried for patients who underwent lumbar decompression for degenerative spine conditions. Patients were divided into 2 cohorts: those with lumbar spine facet cysts and those without. Retrospective propensity-score matching was performed using 13 baseline variables to adjust for potential confounding factors, including age, sex, race, body mass index, and comorbidities. Secondary analysis comparing outcomes in patients with facet cysts cases undergoing decompression only versus those undergoing decompression and fusion was conducted. Results: A total of 6768 patients were reviewed, of which 188 (2.8%) had facet cysts, which underwent lumbar decompression during 2019–2023. After 3:1 matching, patients with facet cysts were compared with 564 patients without it. We found no significant differences in LOS, nonroutine discharge, postoperative complications, readmissions, and reoperations. In addition, in cases with facet cysts, decompression reported no increased risk for discharge opioids, readmissions, and reoperations, whereas fusion (in a separate cohort of 127 patients with facet cysts) was associated with an increased risk for nonroutine discharge (3.7% vs. 10.2%, P=0.021), complications (2.1% vs. 7.1%, P=0.042), and longer LOS (0.89±1.69 vs. 3.74±2.03 d, P<0.001) and operative time (138.78±62.99 vs. 273.07±111.51 min, P <0.001). Conclusions: The presence of facet cysts does not significantly affect outcomes of lumbar decompression for degenerative spine disease. Decompression alone for facet cysts can have better outcomes than decompression and fusion. The need for fusion should be weighted with its higher risks of complications, longer hospital stays, and nonroutine discharges.

ABSTRACTDegenerative disk disease of the spine is a major cause of back pain and disability. Optimization of regenerative medical therapies for degenerative disk disease requires a deep mechanistic understanding of the factors controlling the structural integrity of spinal tissues. In this investigation, we sought to identify candidate regulatory genes controlling extracellular matrix synthesis in spinal tissues. To achieve this goal we performed high throughput next generation RNA sequencing on 39 annulus fibrosus and 21 nucleus pulposus human tissue samples. Specimens were collected from patients undergoing surgical discectomy for the treatment of degenerative disk disease. Our studies identified associations between extracellular matrix genes, growth factors, and other important regulatory molecules. The fibrous matrix characteristic of annulus fibrosus was associated with expression of the growth factors platelet derived growth factor beta (PDGFB), vascular endothelial growth factor C (VEGFC), and fibroblast growth factor 9 (FGF9). Additionally we observed high expression of multiple signaling proteins involved in the NOTCH and WNT signaling cascades. Nucleus pulposus extracellular matrix related genes were associated with the expression of numerous diffusible growth factors largely associated with the transforming growth signaling cascade, including transforming factor alpha (TGFA), inhibin alpha (INHA), inhibin beta A (INHBA), bone morphogenetic proteins (BMP2, BMP6), and others. Clinical significance: this investigation provides important data on extracellular matrix gene regulatory networks in disk tissues. This information can be used to optimize pharmacologic, stem cell, and tissue engineering strategies for regeneration of the intervertebral disk and the treatment of back pain. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1356–1369, 2018.