Search

Objective  The suprasellar space is a common location for intracranial lesions. The position of the optic chiasm (prefixed vs. postfixed) results in variable sizes of operative corridors and is thus important to identify when choosing a surgical approach to this region. In this study, we aim to identify relationships between suprasellar anatomy and external cranial metrics to guide in preoperative planning. Methods  T2-weighted magnetic resonance images (MRIs) from 50 patients (25 males and 25 females) were analyzed. Various intracranial and extracranial metrics were measured. Statistical analysis was performed to determine any associations between metrics. Results  Interoptic space (IOS) size correlated with interpupillary distance (IPD; a  = 7.3, 95% confidence interval [CI] = 4.5-10.0, R 2  = 0.3708, p  = 0.0009). IOS size also correlated with fixation of the optic chiasm, for prefixed chiasms ( n  = 7), the mean IOS is 205.14 mm 2 , for normal chiasm position ( n  = 33) the mean IOS is 216.94 mm 2 and for postfixed chiasms ( n  = 10) the mean IOS is 236.20 mm 2 ( p  = 0.002). IPD correlates with optic nerve distance (OND; p  = 0.1534). Cranial index does not predict OND, IPD, or IOS. Conclusion  This study provides insight into relationships between intracranial structures and extracranial metrics. This is the first study to describe a statistically significant correlation between IPD and IOS. Surgical approach can be guided in part by the size of the IOS and its correlates. Particularly small intraoptic space may guide the surgeon away from a subfrontal approach., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Study Design: Retrospective cohort., Objectives: To determine how the number of fused intervertebral levels affects radiographic parameters and clinical outcomes in patients undergoing open posterolateral lumbar fusion (PLF) for low-grade degenerative spondylolisthesis., Methods: This was a retrospective cohort study on patients who underwent open PLF for low-grade spondylolisthesis at a single institution from 2011 to 2018. Patients were divided into groups based on number of levels fused during their procedure (1, 2, or 3 or more). Preoperative and postoperative spinopelvic radiographic parameters, patient-reported outcomes (Visual Analog Scale [VAS]-back, VAS-leg, Oswestry Disability Index [ODI]), and postoperative complications were compared., Results: Of the 316 patients eligible (203 one-level, 95 two-level, 18 three or more levels), change in initial postoperative to final pelvic incidence-lumbar lordosis was greatest in 2-level fusions ( P = .039), while 3 or more level fusions had worse final pelvic tilt measures ( P = .021). In addition, multilevel fusions had worse final VAS-back scores (2-level: P = .015; 3 or more levels: P = .011), higher rates of dural tears (2-level: P = .001), reoperation (2-level: P = .039), and discharge to facility (3 or more levels: P = .047) when compared with 1-level fusions., Conclusions: Patients in multilevel fusions experienced less improvement in back pain, had more complications, and were more commonly discharged to a facility compared with single-level PLF patients. These findings are important for operative planning, for setting appropriate preoperative expectations, and for risk stratification in patients undergoing posterior lumbar fusion for low-grade spondylolisthesis.

Background Context: Patients with back pain predominance (BPP) have traditionally been thought to derive less predictable symptomatic relief from lumbar fusion surgery., Purpose: To compare postoperative clinical outcomes as well as degree of improvement in clinical outcome measures between patients with BPP and patients with leg pain predominance (LPP) undergoing open posterior lumbar fusion., Study Design: Retrospective cohort study., Patient Sample: Analysis of patients who underwent an open posterior lumbar fusion for low-grade (Meyerding Grade I or II) degenerative or isthmic spondylolisthesis from 2011 to 2018 was conducted. Surgery was indicated after failure of conservative treatment to address radiculopathy and/or neurogenic claudication. Patients were excluded if they were under 18 years of age at the time of surgery, had less than 6 months of follow-up, presented with a lumbar vertebral body fracture, tumor, or infection, or underwent a fusion surgery that extended to the thoracic spine, high-grade spondylolisthesis, or concomitant deformity., Outcome Measures: Radiographs obtained at preoperative, immediate postoperative, and final visits were evaluated for presence or absence of fusion. Patient-reported outcomes were recorded at preoperative and final clinic visits that included: visual analog scale (VAS) back/leg pain, and Oswestry disability index (ODI). Achievement of minimal clinically important difference (MCID) was analyzed, along with rates of postoperative complication and reoperation., Methods: Preoperative and final patient-reported outcomes were obtained. Achievement of MCID was evaluated using following thresholds: ODI 14.9, VAS-back pain 2.1, VAS-leg pain 2.8. For analysis, patients were divided into two groups based on predominant location of pain: predominantly VAS-back pain (BPP) and predominantly VAS-leg pain (LPP)., Results: One hundred forty-one patients met inclusion criteria. Of these, 71 had LPP, and 70 had BPP. Patients with preoperative LPP experienced greater improvements in VAS-leg (p<.001) compared to those with BPP, whereas patients with preoperative BPP experienced greater improvements in VAS-back (p=.011) postoperatively compared to those with LPP. There were no differences in the final clinical outcomes. Additionally, LPP achieved MCID for VAS-leg (p=.027) at significantly higher proportion than BPP and BPP achieved MCID for VAS-back (p=.050) at significantly higher proportion than LPP., Conclusions: Patients with low-grade spondylolisthesis who underwent an open posterior lumbar fusion had improvement in symptoms regardless of presentation with BPP or LPP. In properly indicated patients, posterior spinal fusion is effective for those with BPP in the setting of experiencing both leg and back pain, and clinicians can use this information for perioperative discussions and surgical decision-making., (Copyright © 2019. Published by Elsevier Inc.)