Should Surgery for Adult Degenerative Lumbar Deformity be Staged? No abstract available

Lumbar Spinal Stenosis and Degenerative Spondylolisthesis: A Review of the SPORT Literature The Spine Patient-Reported Outcomes Related Trial (SPORT) is arguably one of the most impactful and insightful studies conducted in spine surgery. Designed as a prospective, multicenter study with randomized and observational cohorts, SPORT has provided vast data on the pathogenesis, treatment effects, clinical outcomes, cost effectiveness of disk herniation, lumbar spinal stenosis, and degenerative spondylolisthesis. With regards to spinal stenosis and degenerative spondylolisthesis, SPORT has demonstrated a sustained benefit from surgical intervention at 2, 4, and 8 years postoperatively. Myriad subgroup analyses have subsequently been performed that have also resulted in clinically relevant findings. These analyses have assessed incidence and risk factors for reoperations and intraoperative complications, impact of patient comorbidities and host factors, influence of epidural injections, patient decision-making, and role of nonoperative therapy. This has resulted in significant findings that may allow spine surgeons to optimize patient outcomes while managing expectations appropriately.

Minimally Invasive Cervical Pedicle Screw Fixation (MICEPS) via a Posterolateral Approach Cervical pedicle screw (PS) fixation provides great mechanical strength; however, it needs wide soft tissue detachment and has vertebral artery damage risk. Minimally invasive cervical pedicle screw (MICEPS) fixation, a new method for cervical PS fixation through a posterolateral approach, was developed to reduce soft tissue damage and avoid lateral misplacement of screws. Sixty-seven patients with cervical injury underwent MICEPS fixation. They were positioned prone on a radiolucent carbon table with a carbon Mayfield frame. A reference frame was attached to the spinous process through a small skin incision. One or 2 lateral incisions were made for screw insertion under navigation guidance. After the nuchal fascia was cut, the lateral mass was exposed with blunt dissection between the levator scapulae and splenius muscles. A self-retaining tubular retractor with illumination was applied between split muscle fibers. A 1.4-mm K-wire was inserted using an electric driver under navigation guidance. Drill and tap and cannulated PSs were sequentially inserted over the K-wire; facet fusion via bone grafting can be performed at this time. The rod was placed to the screw head. This technique can reduce intraoperative bleeding and screw deviation rate, with neither of the misplaced screws deviating laterally in the MICEPS group.

Does Hospital Volume Affect Outcomes in Spine Surgeries? A Systematic Review Study Design: Systematic review. Objective: To assess the impact of hospital volume on postoperative outcomes in spine surgery. Summary of Background Data: Several strategies have recently been proposed to optimize provider outcomes, such as regionalization to higher volume centers and setting volume benchmarks. Materials and Methods: We performed a systematic review examining the association between hospital volume and spine surgery outcomes. To be included in the review, the study population had to include patients undergoing a primary or revision spinal procedure. These included anterior/posterior cervical fusions, anterior/posterior lumbar fusions, laminectomies, discectomies, spinal deformity surgeries, and surgery for spinal malignancies. We searched the Pubmed, OVID MEDLINE (1966–2018), Google Scholar, and Web of Science (1900–2018) databases in January 2018 using the search criteria (“Hospital volume” OR “volume” OR “volume-outcome” OR “volume outcome”) AND (“spine” OR “spine surgery” OR “lumbar” OR “cervical” OR “decompression” OR “deformity” OR “fusions”). There were no restrictions placed on study design, publication date, or language. The studies were evaluated with respect to the quality of methodology as outlined by the Grading of Recommendations Assessment, Development, and Evaluation system. Results: Twelve studies were included in the review. Studies were variable in defining hospital volume thresholds. Higher hospital volume was associated with statistically significant lower risks of postoperative complications, a shorter length of stay, lower cost of hospital stay, and a lower risk of readmissions and reoperations/revisions. Conclusions: Our findings suggest a trend toward better outcomes for higher volume hospitals; however, further study needs to be carried out to define objective volume thresholds for specific spine surgeries for hospitals to use as a marker of proficiency.

How to Write an Effective Results Section Developing a well-written research paper is an important step in completing a scientific study. This paper is where the principle investigator and co-authors report the purpose, methods, findings, and conclusions of the study. A key element of writing a research paper is to clearly and objectively report the study’s findings in the Results section. The Results section is where the authors inform the readers about the findings from the statistical analysis of the data collected to operationalize the study hypothesis, optimally adding novel information to the collective knowledge on the subject matter. By utilizing clear, concise, and well-organized writing techniques and visual aids in the reporting of the data, the author is able to construct a case for the research question at hand even without interpreting the data.

Factors Influencing Interbody Cage Subsidence Following Anterior Cervical Discectomy and Fusion Study Design: This is a prospective study. Objective: The purpose of this study was to analyze the factors influencing subsidence following anterior cervical discectomy and fusion (ACDF) using a stand-alone cage. Summary of Background Data: The relationship between cage subsidence and cage height and material has been reported in previous studies. Methods: Clinical and radiologic data from 78 patients, 105 levels, undergoing single-level and 2-level ACDF without plates from 2007 to 2015 were collected prospectively. Patients were followed for at least 12 months after surgery. Radiographs were obtained preoperatively, at 1 week, and at 1, 3, 6, and 12 months postoperatively to determine the presence of fusion and cage subsidence. Results: There was a correlation in cage height and subsidence (Spearman P<0.05). Cage subsidence was significantly shorter in the polyetheretherketone cages than in titanium cages (P<0.05). However, when cage height was <5 mm, the difference between the 2 groups was not significant. Large subsidence (>3 mm) was observed in 17 patients, 20 levels, many of whom exhibited sinking in the first month after surgery. Conclusions: The greater the cage height, the greater the risk of cage subsidence in ACDF. Polyetheretherketone cages are superior to titanium cages for the maintenance of intervertebral height in cases where cage height is >5.5 mm. Level of Evidence: Level 3.

Optical Topographic Imaging for Spinal Intraoperative 3-Dimensional Navigation in the Cervical Spine: Initial Preclinical and Clinical Feasibility Summary of Background Data: Computer-assisted 3-dimensional navigation may guide spinal instrumentation. Optical topographic imaging (OTI) is a novel navigation technique offering comparable accuracy and significantly faster registration workflow relative to current navigation systems. It has previously been validated in open posterior thoracolumbar exposures. Objective: To validate the utility and accuracy of OTI in the cervical spine. Study Design: This is a prospective preclinical cadaveric and clinical cohort study. Methods: Standard midline open posterior cervical exposures were performed, with segmental OTI registration at each vertebral level. In cadaveric testing, OTI navigation guidance was used to track a drill guide for cannulating screw tracts in the lateral mass at C1, pars at C2, lateral mass at C3–6, and pedicle at C7. In clinical testing, translaminar screws at C2 were also analyzed in addition. Planned navigation trajectories were compared with screw positions on postoperative computed tomographic imaging, and quantitative navigation accuracies, in the form of absolute translational and angular deviations, were computed. Results: In cadaveric testing (mean±SD) axial and sagittal translational navigation errors were (1.66±1.18 mm) and (2.08±2.21 mm), whereas axial and sagittal angular errors were (4.11±3.79 degrees) and (6.96±5.40 degrees), respectively. In clinical validation (mean±SD) axial and sagittal translational errors were (1.92±1.37 mm) and (1.27±0.97 mm), whereas axial and sagittal angular errors were (3.68±2.59 degrees) and (3.47±2.93 degrees), respectively. These results are comparable to those achieved with OTI in open thoracolumbar approaches, as well as using current spinal neuronavigation systems in similar applications. There was no radiographic facet, canal or foraminal violations, nor any neurovascular complications. Conclusions: OTI is a novel navigation technique allowing efficient initial and repeat registration. Accuracy even in the more mobile cervical spine is comparable to current spinal neuronavigation systems.

Sex-specific and Age-specific Analgesia for Early Postoperative Pain Management After Lumbar Decompressive Surgery: A Randomized Clinical Trial Study Design: This was a randomized clinical trial. Objective: To compare the efficacy and safety of nonsteroidal anti-inflammatory drug and opioid for acute pain management after lumbar decompressive surgery. Summary of Background Data: Multimodal analgesia is associated with synergistic effects while reducing opioid-related adverse effects. However, there is no consensus on the ideal multimodal analgesic regimen. We assumed that each agent in various multimodal regimens under different conditions may have different effects. Materials and Methods: This prospective randomized clinical trial recruited adult patients who underwent single-level lumbar decompressive surgery. Patients were randomized to receive our postoperative analgesic regimen including either nonsteroidal anti-inflammatory drug (celecoxib) or opioid (extended-release oxycodone) from postoperative day 3 to 14. The Visual Analog Scale (VAS) and Oswestry Back Pain Disability Index (ODI) were used to evaluate effectiveness preoperatively and on postoperative days 2, 3, 7, and 14, and at 6 months. Drug-related adverse effects were also recorded. Results: One hundred patients were enrolled and 93 patients (46 patients with celecoxib vs. 47 patients with oxycodone) were randomized. No differences were observed in patient demographics and preoperative VAS and ODI between the 2 groups. VAS and ODI were not different at all postoperative time points. However, subanalysis according to sex and age, revealed significant differences in efficacy: celecoxib was effective in female individuals and oxycodone was effective in male individuals on postoperative days 7 and 14; oxycodone was effective in patients aged above 65 years on postoperative days 7 and 14. Although nausea/vomiting and constipation were more common in the oxycodone group than in the celecoxib group, other adverse effects were not different. Conclusions: In patients who underwent single-level lumbar decompressive surgery, treatment with celecoxib and oxycodone for postoperative pain management showed no significant differences in efficacy. However, subanalysis showed that each drug was effective in different ages and sex groups. Level of Evidence: Level II.

Clinical Outcome After Anterior Lumbar Interbody Fusion With a New Osteoinductive Bone Substitute Material: A Randomized Clinical Pilot Study Study Design: Pilot, single-center, single-blinded, parallel-group, randomized clinical study. Objective: The aim of this study was to pilot a randomized clinical study to evaluate whether instrumented anterior lumbar interbody fusion (ALIF) with a new nanocrystalline hydroxyapatite embedded in a silica gel matrix (NH-SiO2) leads to superior radiologic and clinical outcomes at 12-month follow-up compared with instrumented ALIF with homologous bone. Summary of Background Data: ALIF completed with interbody cages is an established technique for performing arthrodesis of the lumbar spine. There is ongoing discussion about which cage-filling material is most appropriate. This is the first study to assess the efficacy of NH-SiO2 in ALIF surgery. Materials and Methods: This randomized, clinical, pilot trial included 2 groups of 20 patients with monosegmental or multisegmental degenerative disease of the lumbar spine who were suitable to undergo monosegmental or bisegmental ALIF fusion at the level L4/L5 and L5/S1 with a carbon fiber reinforced polymer ALIF cage filled with either NH-SiO2 or homogenous bone. Primary outcome was postoperative disability as measured by the Oswestry Disability Index (ODI). Secondary outcomes were postoperative radiographic outcomes, pain, and quality of life. Patients were followed 12 months postoperatively. Results: Mean (±SD) 12-month ODI was 24±17 in the NH-SiO2 group and 27±19 in the homologous bone group (P=0.582). Postoperative radiography, functional outcomes, and quality-of-life indices did not differ significantly between groups at any of the regularly scheduled follow-up visits. Conclusions: This clinical study showed similar functional, radiologic, and clinical outcomes 12 months postoperatively for instrumented ALIF procedures with the use of NH-SiO2 or homologous bone as cage filling. In the absence of any relevant differences in outcome, we postulate that the pivotal clinical study should be designed as an equivalence trial.

Correlation of Lower Instrumented Vertebra With Spinal Mobility and Health-related Quality of Life After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis Study Design: This is a retrospective single-center and single-surgeon study. Objective: We investigated the correlation between lower instrumented vertebra (LIV) and spinal mobility 2 years after posterior spinal fusion with pedicle screws for adolescent idiopathic scoliosis (AIS) for optimal LIV selection. Summary of Background: Spinal motion can become limited in scoliosis patients who undergo posterior spinal fusion. However, few reports exist on spinal mobility after posterior spinal fusion for AIS and the relationship between the LIV and mobility is unknown. We hypothesize that mobility limitation increases as the LIV is moved inferiorly. Data: Of 72 consecutive patients who received posterior spinal fusion using pedicle screws for AIS between October 2009 and August 2015, 66 patients (5 male and 61 female, mean age: 14.9 y) were enrolled. Materials and Methods: In total, 66 patients were retrospectively reviewed after stratification according to LIV level. Follow-up rate was 91.7%. Patients were examined for the fingertip-to-floor distance (FFD) before and 2 years after surgery. FFD was measured from the tips of the middle fingers to the floor with the barefoot subject bent maximally forward and the feet together and knees straight. Clinical outcome was assessed using Scoliosis Research Society-22 patient questionnaire (SRS-22r) scores and a visual analog scale for low back pain before and at 2 years postoperatively. Results: The median number of fused vertebrae was 9 (range: 4–15). The LIV was T11–12 in 15 patients, L1 in 11 patients, L2 in 10 patients, and L3 in 30 patients. The median decrease in FFD according to LIV at 2 years after surgery was T11–12: 0 cm, L1: 0 cm, L2: 5.5 cm, and L3: 10 cm. Thus, limited FFD became significantly more severe as the LIV was moved downwards (P<0.01). There were no significant correlations between limited FFD and SRS-22r or pain visual analog scale scores at 2 years postoperatively. Conclusions: FFD became significantly more restricted as the LIV was moved inferiorly but clinical results appeared unaffected by limited FFD.