Cort D. Lawton

Incidence of lumbar spine pedicle breach after percutaneous screw fixation: a radiographic evaluation of 601 screws in 151 patients.

Study Design: Prospective clinical study. Objectives: Although percutaneous pedicle screw fixation continues to be increasingly practiced, there remain few reports specifically addressing the accuracy and clinical safety of this technique. The goal of this study is to evaluate the accuracy of fluoroscopically guided pedicle screw placement in the lumbar spine. Summary of Background Data: Pedicle breach rates vary substantially in the literature. Pedicle breach rates have been reported to be as high as 29% with the traditional, open technique. With the use of computer-assisted 2-dimensional fluoroscopy, breach rates have been reported between 5% and 23%. Furthermore, in a series of 225 pedicles instrumented with 3-dimensional fluoroscopy, the reported breach rate was 1.8%. Methods: A total of 151 patients were evaluated after instrumented single-level or 2-level minimally invasive transforaminal lumbar interbody fusion with 601 screws placed for percutaneous fixation. The treated patients had an average age of 56.6 y (20–85 y) and there were 129 cases of single-level and 22 cases of 2-level. The levels of pedicle screw fixation included (level, patient numbers): L1/L2 (1), L2/L3 (2), L3/L4 (33), L4/L5 (101), L5/S1 (46). Radiographic results included postoperative computed tomographic scan. Patients were followed prospectively for potential clinical symptoms. Results: In a total of 601 instrumented pedicles, there were 37 pedicle breaches (6.2%). Of these, 22 (3.7%) were significant breaches (≥3 mm). The level of the breached pedicles were L3 (5/46, 10.2%), L4 (12/201, 7.0%), L5 (15/158, 9.5%), S1 (3/47, 3.4%). The side/location of breach was characterized as follows: medial (22), lateral (12), superior (2), and inferior (1). There were 2 symptomatic breaches, both associated with a medial breach at the L5 pedicle. Symptoms from these events were transient and did not require hardware repositioning. There were no other complications. Conclusions: Percutaneous pedicle screw fixation in the lumbar spine continues to be a technique embraced by modern spinal surgeons. The use of intraoperative fluoroscopic guidance is both a clinically safe and accurate method for instrumentation and is of comparable accuracy to other techniques. Although trajectory errors may occur, they are of rare clinical significance.

Leptomeningeal spinal metastases from glioblastoma multiforme: treatment and management of an uncommon manifestation of disease.

Glioblastoma multiforme (GBM) is one of the most common and aggressive primary brain tumors, composing 12%-20% of all intracranial tumors in adults. Average life expectancy is merely 12-14 months following initial diagnosis. Patients with this neoplasm have one of the worst 5-year survival rates among all cancers despite aggressive multimodal treatment consisting of maximal tumor resection, radiation therapy, and adjuvant chemotherapy. With recent advancements in management strategies, there has been improvement in the overall trend in patient outcomes; however, recurrence remains nearly inevitable. While most tumors recur locally, metastases to distal locations have become more common. Specifically, the last decade has seen an increased incidence of spinal metastases, representing an emerging complication in patients with intracranial GBM. However, the literature regarding prevention strategies and the presentation of spinal metastases has remained scarce. As local control of primary lesions continues to improve, more cases of spinal metastases are likely to be seen. In this review the authors present a new case of metastatic GBM to the L-5 nerve root, and they summarize previous cases of intracranial GBM with leptomeningeal spinal metastatic disease. They also characterize key features of this disease presentation and discuss areas of future investigation necessary for enhanced prevention and treatment of this complication.

Minimally invasive transforaminal lumbar interbody fusion: a perspective on current evidence and clinical knowledge.

This paper reviews the current published data regarding open transforaminal lumbar interbody fusion (TLIF) in relation to minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Introduction. MI-TLIF, a modern method for lumbar interbody arthrodesis, has allowed for a minimally invasive method to treat degenerative spinal pathologies. Currently, there is limited literature that compares TLIF directly to MI-TLIF. Thus, we seek to discuss the current literature on these techniques. Methods. Using a PubMed search, we reviewed recent publications of open and MI-TLIF, dating from 2002 to 2012. We discussed these studies and their findings in this paper, focusing on patient-reported outcomes as well as complications. Results. Data found in 14 articles of the literature was analyzed. Using these reports, we found mean follow-up was 20 months. The mean patient study size was 52. Seven of the articles directly compared outcomes of open TLIF with MI-TLIF, such as mean duration of surgery, length of post-operative stay, blood loss, and complications. Conclusion. Although high-class data comparing these two techniques is lacking, the current evidence supports MI-TLIF with outcomes comparable to that of the traditional, open technique. Further prospective, randomized studies will help to further our understanding of this minimally invasive technique.

Outcome following unilateral versus bilateral instrumentation in patients undergoing minimally invasive transforaminal lumbar interbody fusion: A single-center randomized prospective study

OBJECT Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is used to treat a wide variety of lumbar degenerative disorders. Although there are some reports showing efficacy of unilateral instrumentation during MIS-TLIF, a controlled randomized prospective study has not been done. METHODS Forty-one patients were randomly assigned to receive either bilateral or unilateral instrumentation following 1-level unilateral MIS-TLIF. Four patients were lost to follow-up in the unilateral group and 1 patient was lost to follow-up in the bilateral group. Preoperative and postoperative scores on a visual analog scale (VAS) for back pain and leg pain (VAS-BP and VAS-LP, respectively), Oswestry Disability Index (ODI), and 36-Item Short Form Healthy Survey version 2 (SF-36v2) were collected. Additionally, preoperative and postoperative segmental Cobb angles and radiographic evidence of fusion were analyzed. RESULTS There was no statistically significant difference in baseline demographic characteristics between the 2 groups. The VAS-BP, VAS-LP, ODI, and SF-36v2 physical component scores improved significantly after surgery in both groups (p < 0.05); there was no statistically significant between-groups difference in the degree of improvement. Blood loss was significantly higher in the bilateral instrumentation group and hospital stay was longer in the unilateral instrumentation group. There was no statistically significant between-groups difference with respect to change in segmental lordosis or fusion rate. The average duration of follow-up was 12.4 months for the bilateral instrumentation group and 11.4 months for the unilateral instrumentation group. CONCLUSIONS Clinical and radiographic outcomes of unilateral and bilateral instrumentation for unilateral MISTLIF are similar 1 year after surgery.

Clinical Outcomes of Microendoscopic Foraminotomy and Decompression in the Cervical Spine

OBJECTIVE Few reports have addressed long-term outcomes, as well as the safety and efficacy of the cervical microendoscopic foraminotomy (CMEF) and cervical microendoscopic diskectomy (CMED) procedures used in modern spine practice to treat degenerative disease of the cervical spine. Accordingly, we present long-term outcomes from a cohort of patients treated for foraminal stenosis or disk herniation with the CMEF or CMED procedure, respectively. METHODS A total of 38 patients were included in the study, with a mean follow-up of 24.47 ± 12.84 months. Patients were monitored prospectively with questionnaires consisting of a visual analog scale for the neck (VASN) and arm (VASA), and a neck disability index (NDI) form. Operative time, estimated blood loss, and hospitalization stay also were collected. Data were analyzed with Microsoft Office Excel 2007. RESULTS The mean 1 year follow-up scores all showed statistically significant improvements: NDI (P = 0.0019), VASN (P = 0.0017), VASA (P ≤ 0.0001). Similar results were seen at 2-year follow-up: NDI (P = 0.0011), VASN (P = 0.0022), and VASA (P ≤ 0.0001); and at 3- to 6-year follow-up: NDI (P = 0.0015), VASN (P = 0.0200), and VASA (P = 0.0034). The average operation time, hospitalization stay, and estimated blood loss were 154.27 ± 26.79 minutes, 21.22 ± 14.23 hours, and 27.92 mL, respectively. There were no statistically significant differences when patients were compared by age (over 50 vs. under 50), operative level (above C6 vs. below C6), or sex. One complication was reported in this study consisting of duratomy, which required no further intervention. CONCLUSION Posterior CMEF and CMED are safe and effective procedures for minimally invasive decompression in the cervical spine.

Evidence-based management of central cord syndrome

OBJECT Evidence-based medicine is used to examine the current treatment options, timing of surgical intervention, and prognostic factors in the management of patients with traumatic central cord syndrome (TCCS). METHODS A computerized literature search of the National Library of Medicine database, Cochrane database, and Google Scholar was performed for published material between January 1966 and February 2013 using key words and Medical Subject Headings. Abstracts were reviewed and selected, with the articles segregated into 3 main categories: surgical versus conservative management, timing of surgery, and prognostic factors. Evidentiary tables were then assembled, summarizing data and quality of evidence (Classes I-III) for papers included in this review. RESULTS The authors compiled 3 evidentiary tables summarizing 16 studies, all of which were retrospective in design. Regarding surgical intervention versus conservative management, there was Class III evidence to support the superiority of surgery for patients presenting with TCCS. In regards to timing of surgery, most Class III evidence demonstrated no difference in early versus late surgical management. Most Class III studies agreed that older age, especially age greater than 60-70 years, correlated with worse outcomes. CONCLUSIONS No Class I or Class II evidence was available to determine the efficacy of surgery, timing of surgical intervention, or prognostic factors in patients managed for TCCS. Hence, there is a need to perform well-controlled prospective studies and randomized controlled clinical trials to further investigate the optimal management (surgical vs conservative) and timing of surgical intervention in patients suffering from TCCS.

Evidence-based management of deep wound infection after spinal instrumentation

In this study, evidence-based medicine is used to assess optimal surgical and medical management of patients with post-operative deep wound infection following spinal instrumentation. A computerized literature search of the PubMed database was performed. Twenty pertinent studies were identified. Studies were separated into publications addressing instrumentation retention versus removal and publications addressing antibiotic therapy regimen. The findings were classified based on level of evidence (I-III) and findings were summarized into evidentiary tables. No level I or II evidence was identified. With regards to surgical management, five studies support instrumentation retention in the setting of early deep infection. In contrast, for delayed infection, the evidence favors removal of instrumentation at the time of initial debridement. Surgeons should be aware that for deformity patients, even if solid fusion is observed, removal of instrumentation may be associated with significant loss of correction. A course of intravenous antibiotics followed by long-term oral suppressive therapy should be pursued if instrumentation is retained. A shorter treatment course may be appropriate if hardware is removed.

Minimally Invasive Transforaminal Lumbar Interbody Fusion (TLIF) for Spondylolisthesis in 282 Patients: In Situ Arthrodesis versus Reduction

OBJECTIVE The benefits of spondylolisthesis reduction via minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) remain poorly understood. The purpose was to compare the complications, perioperative factors, and fusion rates in patients undergoing MI-TLIF for degenerative spondylolisthesis between those in whom reduction was or was not performed. METHODS INCLUSION CRITERIA 1) patients who underwent a 1, 2, or 3 level MI-TLIF and 2) had a preoperative diagnosis of degenerative spondylolisthesis (Meyerding grade >0). EXCLUSION CRITERIA >10° coronal curves, significant sagittal malalignment, infection, and preoperative hardware failure. Patients were grouped on the basis of those who underwent reduction of the spondylolisthesis by at least 1 Meyerding grade (RED) and those who did not (NORED). RESULTS A total of 282 patients were included: RED (162, 57.4%) and NORED (120, 42.6%). Mean ages (61.68 ± 10.43 vs. 61.88 ± 11.76 years, respectively, P > 0.05) and operative times (P > 0.05) were statistically similar. RED had a significantly larger EBL (280.2 ± 24.03 vs. 212.61 ± 17.54, P < 0.05). The length of hospital stay, intraoperative complications, postoperative medical and surgical complications, and disposition were statistically similar between groups (P > 0.05, for all). RED had a significantly higher percentage of patients with a successful fusion at 1 year than NORED (84.50% vs. 70.83%, P < 0.05). CONCLUSION Reduction of spondylolisthesis was not associated with an increase in operative time, length of stay, and perioperative and postoperative complications compared with fusion in situ. Reduction was associated with higher blood loss but also a higher rate of fusion success at 1 year. Overall, reduction did not incur additional risk and had positive perioperative outcomes.

Comparison of open and minimally invasive surgery for intradural-extramedullary spine tumors.

OBJECT Patients with symptomatic intradural-extramedullary (ID-EM) tumors may be successfully treated with resection of the lesion and decompression of associated neural structures. Studies of patients undergoing open resection of these tumors have reported high rates of gross-total resection (GTR) with minimal long-term neurological deficit. Case reports and small case series have suggested that these patients may be successfully treated with minimally invasive surgery (MIS). These studies have been limited by small patient populations. Moreover, there are no studies directly comparing perioperative outcomes between patients treated with open resection and MIS. The objective of this study was to compare perioperative outcomes in patients with ID-EM tumors treated using open resection or MIS. METHODS A retrospective review was performed using data collected from 45 consecutive patients treated by open resection or MIS for ID-EM spine tumors. These patients were treated over a 9-year period between April 2003 and October 2012 at Northwestern University and the University of Chicago. Statistical analysis was performed to compare perioperative outcomes between the two groups. RESULTS Of the 45 patients in the study, 27 were treated with the MIS approach and 18 were treated with the open approach. Operative time was similar between the two groups: 256.3 minutes in the MIS group versus 241.1 minutes in the open group (p = 0.55). Estimated blood loss was significantly lower in the MIS group (133.7 ml) compared with the open group (558.8 ml) (p < 0.01). A GTR was achieved in 94.4% of the open cases and 92.6% of the MIS cases (p = 0.81). The mean hospital stay was significantly shorter in the MIS group (3.9 days) compared with the open group (6.1 days) (p < 0.01). There was no significant difference between the complication rates (p = 0.32) and reoperation rates (p = 0.33) between the two groups. Multivariate analysis demonstrated an increased rate of complications in cervical spine tumors (OR 15, p = 0.05). CONCLUSIONS Thoracolumbar ID-EM tumors may be safely and effectively treated with either the open approach or an MIS approach, with an equivalent rate of GTR, perioperative complication rate, and operative time. Patients treated with an MIS approach may benefit from a decrease in operative blood loss and shorter hospital stays.

Total ankle arthroplasty versus ankle arthrodesis—a comparison of outcomes over the last decade

BackgroundThe surgical treatment of end-stage tibiotalar arthritis continues to be a controversial topic. Advances in surgical technique and implant design have lead to improved outcomes after both ankle arthrodesis (AA) and total ankle arthroplasty (TAA), yet a clear consensus regarding the most ideal form of treatment is lacking. In this study, the outcomes and complications following AA and TAA are compared in order to improve our understanding and decision-making for care and treatment of symptomatic tibiotalar arthritis.MethodsStudies reporting on outcomes and complications following TAA or AA were obtained for review from the PubMed database between January 2006 and July 2016. Results from studies reporting on a minimum of 200 total ankle arthroplasties or a minimum of 80 ankle arthrodesis procedures were reviewed and pooled for analysis. All studies directly comparing outcomes and complications between TAA and AA were also included for review. Only studies including modern third-generation TAA implants approved for use in the USA (HINTEGRA, STAR, Salto, INBONE) were included.ResultsA total of six studies reporting on outcomes following TAA and five reporting on outcomes following AA met inclusion criteria and were included for pooled data analysis. The adjusted overall complication rate was higher for AA (26.9%) compared to TAA (19.7%), with similar findings in the non-revision reoperation rate (12.9% for AA compared to 9.5% for TAA). The adjusted revision reoperation rate for TAA (7.9%) was higher than AA (5.4%). Analysis of results from ten studies directly comparing TAA to AA suggests a more symmetric gait and less impairment on uneven surfaces after TAA.ConclusionsPooled data analysis demonstrated a higher overall complication rate after AA, but a higher reoperation rate for revision after TAA. Based on the existing literature, the decision to proceed with TAA or AA for end-stage ankle arthritis should be made on an individual patient basis.