Single-Level Minimally Invasive Transforaminal Lumbar Interbody Fusion Provides Sustained Improvements in Clinical and Radiological Outcomes up to 5 Years Postoperatively in Patients with Neurogenic Symptoms Secondary to Spondylolisthesis.

STUDY DESIGN: Retrospective review of prospective registry data. PURPOSE: To determine 5-year clinical and radiological outcomes of single-level instrumented minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in patients with neurogenic symptoms secondary to spondylolisthesis. OVERVIEW OF LITERATURE: MIS-TLIF and open approaches have been shown to yield comparable outcomes. This is the first study to assess MIS-TLIF outcomes using the minimal clinically important difference (MCID) criterion. METHODS: The outcomes of 56 patients treated by a single surgeon, including the Oswestry disability index (ODI), neurogenic symptom score, short-form 36 questionnaire (SF-36), and visual analog scale (VAS) scores for back pain (BP), and leg pain (LP), were collected prospectively for up to 5 years postoperatively. Radiological outcomes included adjacent segment degeneration, fusion, cage subsidence, and screw loosening rates. RESULTS: Our patients were predominantly female (71.4%) and had a mean age of 53.7±11.3 years and mean body mass index of 25.7±3.7 kg/m2. The mean operative time, blood loss, time to ambulation, and hospitalization were 167±49 minutes, 126±107 mL, 1.2±0.4 days, and 2.8±1.1 days, respectively. The mean fluoroscopic time was 58.4±33 seconds, and the mean postoperative intravenous morphine dose was 8±2 mg. Regarding outcomes, postoperative scores improved relative to preoperative scores, and this was sustained across various time points for up to 5 years (p<0.001). Improvements in ODI, SF-36, VAS-BP, and VAS-LP all met the MCID criterion. Notably, 5.4% of our patients developed clinically significant adjacent segment disease during follow-up, and 7 minor complications were reported. CONCLUSIONS: Single-level instrumented MIS-TLIF is suitable for patients with neurogenic symptoms secondary to lumbar spondylolisthesis and is associated with an acceptable complication rate. Both clinical and radiological outcomes were sustained up to 5 years postoperatively, with many patients achieving an MCID.

The Subaxial Cervical Spine Injury Classification System: an external agreement validation study.

BACKGROUND CONTEXT: In 2007, the Subaxial Cervical Spine Injury Classification (SLIC) system was introduced demonstrating moderate reliability in an internal validation study. PURPOSE: To assess the agreement on the SLIC system using clinical data from a spinal trauma population and whether the SLIC treatment algorithm outcome improved agreement on treatment decisions among surgeons. STUDY DESIGN: An external classification validation study. PATIENT SAMPLE: Twelve spinal surgeons (five consultants and seven fellows) assessed 51 randomly selected cases. OUTCOME MEASURES: Raw agreement, Fleiss kappa, and intraclass correlation coefficient statistics were used for reliability analysis. Majority rules and latent class modeling were used for accuracy analysis. METHODS: Fifty-one randomly selected cases with significant injuries of the cervical spine from a prospective consecutive series of trauma patients were assessed using the SLIC system. Neurologic details, plain radiographs, and computed tomography scans were available for all cases as well as magnetic resonance imaging in 21 cases (41%). No funds were received in support of this study. The authors have no conflict of interest in the subject of this article. RESULTS: The inter-rater agreement on the most severely affected level of injury was strong (κ=0.76). The agreement on the morphologic injury characteristics was poor (κ=0.29) and agreement on the integrity of the discoligamentous complex was average (κ=0.46). The inter-rater agreement on the treatment verdict after the total SLIC injury severity score was slightly lower than the surgeons' agreement on personal treatment preference (κ=0.55 vs. κ=0.63). Latent class analysis was not converging and did not present accurate estimations of the true classification categories. Based on these findings, no second survey for testing intrarater agreement was performed. CONCLUSIONS: We found poor agreement on the morphologic injury characteristics of the SLIC system, and its treatment algorithm showed no improved agreement on treatment decisions among surgeons. The authors discuss that the reproducibility of the SLIC system is likely to improve when unambiguous true morphologic injury characteristics are being implemented.

In the era of recombinant BMP, does additional anterior stabilization add value to a posterolateral fusion?

STUDY DESIGN: Retrospective cohort study. Clinical question or objective: Is there a benefit to additional transforaminal lumbar interbody fusion (TLIF) if a solid posterolateral (PL) fusion can be achieved with routine bone morphogenetic protein (BMP) use in low-grade spondylolisthesis? METHODS: We performed a retrospective review of patients who had undergone surgery for grade I or II lumbar spondylolisthesis stratified into two groups. Group 1 had 46 patients who underwent TLIF along with PL instrumented fusion. Group 2 had 40 patients who underwent PL instrumented fusion alone. In both groups, adequate posterior decompression with pedicle screw instrumentation was performed and rhBMP-7 was used. All patients were evaluated clinically using the Oswestry Disability Index (ODI) and by independent radiological examination at 3 and 12 months. RESULTS: At a minimum follow-up of 12 months, there was no statistically significant difference in the rate of fusion. In addition, there were no differences in the proportion of patients who had a minimal clinically significant difference in their ODI. There was a similar rate of complications between each cohort. CONCLUSIONS: The use of BMP was associated with a high rate of PL lumbar fusion. In the presence of a PL fusion, there appears to be little clinical benefit to additional anterior TLIF in degenerative spondylolisthesis. [Table: see text].