Topping-off technique for stabilization of lumbar degenerative instabilities in 322 patients

J Neurosurg Spine 32:366–372, 2020

Semi-rigid instrumentation (SRI) was introduced to take advantage of the concept of load sharing in surgery for spinal stabilization. The authors investigated a topping-off technique in which interbody fusion is not performed in the uppermost motion segment, thus creating a smooth transition from stabilized to free motion segments. SRI using the topping-off technique also reduces the motion of the adjacent segments, which may reduce the risk of adjacent segment disease (ASD), a frequently observed sequela of instrumentation and fusion, but this technique may also increase the possibility of screw loosening (SL). In the present study the authors aimed to systematically evaluate reoperation rates, clinical outcomes, and potential risk factors and incidences of ASD and SL for this novel approach.

METHODS The authors collected data for the first 322 patients enrolled at their institution from 2009 to 2015 who underwent surgery performed using the topping-off technique. Reoperation rates, patient satisfaction, and other outcome measures were evaluated. All patients underwent pedicle screw–based semi-rigid stabilization of the lumbar spine with a polyetheretherketone (PEEK) rod system.

RESULTS Implantation of PEEK rods during revision surgery was performed in 59.9% of patients. A median of 3 motion segments (range 1–5 segments) were included and a median of 2 motion segments (range 0–4 segments) were fused. A total of 89.4% of patients underwent fusion, 73.3% by transforaminal lumbar interbody fusion (TLIF), 18.4% by anterior lumbar interbody fusion (ALIF), 3.1% by extreme lateral interbody fusion (XLIF), 0.3% by oblique lumbar interbody fusion (OLIF), and 4.9% by combined approaches in the same surgery. Combined radicular and lumbar pain according to a visual analog scale was reduced from 7.9 ± 1.0 to 4.0 ± 3.1, with 56.2% of patients indicating benefit from surgery. After maximum follow-up (4.3 ± 1.8 years), the reoperation rate was 16.4%.

CONCLUSIONS The PEEK rod concept including the topping-off principle seems safe, with at least average patient satisfaction in this patient group. Considering the low rate of first-tier surgeries, the presented results seem at least comparable to those of most other series. Follow-up studies are needed to determine long-term outcomes, particularly with respect to ASD, which might be reduced by the presented approach.

Usefulness of Timed Up and Go (TUG) Test for Prediction of Adverse Outcomes in Patients Undergoing Thoracolumbar Spine Surgery

Neurosurgery 2019 DOI:10.1093/neuros/nyz480

Spine surgery rates have increased and the high postoperativemorbidity in these patients result in increased costs. Consequently, it is essential to identify patients at risk of adverse outcomes.

OBJECTIVE: To assess whether preoperative Timed Up and Go (TUG) test performance can predict high-grade postoperative complications.

METHODS: A prospective cohort study of patients undergoing elective thoracolumbar spine surgery in a tertiary care hospital between 2017 and 2018. Patients were assessed preoperatively and assigned to the slow-TUG group if unable to perform or test performance time was ≥18.4 s. Primary outcome: high-grade postoperative complications. Secondary outcomes: overall complications, length of stay (LOS), discharge to healthcare facility, readmission and emergency department (ED) presentation. Patients were followed-up until 6 wk after surgery.

RESULTS: One hundred three patients (mean age 62.95 ± 10.97 yr) were enrolled. Slow- TUG group were more likely to be classified as American Society of Anaesthesiology (ASA) class 3 (74.1% vs 47.4%, P=.02), non-independent (25.9% vs 5.3%, P<.01), and frail (92.3% vs 42.1%, P < .01). TUG was an independent predictor of high-grade complications (adjusted odds ratio (OR): 4.97, 95% CI: 1.18-22.47), overall complications (OR: 3.77, 95% CI: 1.33-11.81), discharge to a skilled-nursing facility (OR: 3.2, 95% CI: 1.00-10.70), readmission within 6 wk of surgery (OR: 9.14, 95% CI: 2.39-41.26) and LOS (adjusted incident rate ratio (IRR): 1.45, 95% CI: 1.16-1.80).

CONCLUSION: Compared to traditional risk factors, TUG is an important predictor of adverse postoperative outcomes and may be used preoperatively to identify high-risk thoracolumbar surgery patients.

 

Anterior Cervical Discectomy and Fusion in the Outpatient Ambulatory Surgery Setting: Analysis of 2000 Consecutive Cases

Neurosurgery 2019 DOI:10.1093/neuros/nyz514

In an effort to improve efficiency of care, ambulatory surgery centers (ASCs) have emerged as lower-cost options. Anterior cervical discectomy and fusion (ACDF) is one of the most prevalent spine surgeries performed and rarely requires overnight stays in the hospital, supporting its migration to the ASC. Recent analyses have called into question the safety of outpatient ACDF, potentially slowing its adoption. ASC-ACDF studies have largely been limited to small series, precluding an accurate assessment of safety.

OBJECTIVE: To analyze 2000 ASC-ACDF cases, describe patient selection and perioperative protocol, and report associated safety profile.

METHODS: A total of 2000 patients who underwent 1 to 3 level ACDF in a single ASC from 2006 to 2018 were included in this retrospective analysis. Patients were observed in a 4-h postanesthesia care unit (PACU) with a multimodal pain management regiment. Data were collected on patient demographics, comorbidities, operative details, and 30- and 90-d morbidity.

RESULTS: Of the 2000 patients, 10 (0.5%) required transfer to an inpatient setting within the 4-h observation. Reasons for transfer included hematoma (2), pain control (2), cerebrospinal fluid leak (1), and medical complications (5). Six patients (0.3%) underwent reoperation within 30 d. All-cause 30-d readmission was 1.9%.

CONCLUSION: An analysis of 2000 ACDF patients in an ASC setting with a standardized perioperative protocol demonstrates that surgical complications occur at a low rate (<1%) and can be appropriately diagnosed and managed in a 4-h PACU. In an effort to decrease healthcare costs, surgeons can safely perform ACDFs in an ASC utilizing patient selection criteria and perioperative management protocols similar to those reported here.

Kambin’s triangle: definition and new classification schema

J Neurosurg Spine 32:390–398, 2020

Kambin’s triangle is an anatomical corridor used to access critical structures in a variety of spinal procedures. It is considered a safe space because it is devoid of vascular and neural structures of importance. Nonetheless, there is currently significant variation in the literature regarding the exact dimensions and anatomical borders of Kambin’s triangle. This confusion was originally caused by leaving the superior articular process (SAP) unassigned in the description of the working triangle, despite Kambin identifying that structure in his original report. The SAP is the most relevant structure to consider when accessing the transforaminal corridor. Leaving the SAP unassigned has led to an open-handed application of the term “Kambin’s triangle.” That single eponym currently has two potential meanings, one meaning for endoscopic surgeons working through a corridor in the intact spine and a second meaning for surgeons accessing the disc space after a complete or partial facetectomy. Nevertheless, an anatomical corridor should have one consistent definition to clearly communicate techniques and use of instrumentation performed through that space. As such, the authors propose a new surgically relevant classification of this corridor. Assigning the SAP a border requires adding another dimension to the triangle, thereby transforming it into a prism. The term “Kambin’s prism” indicates the assignment of a border to all relevant anatomical structures, allowing for a uniform definition of the 3D space. From there, the classification scheme considers the expansion of the corridor and the extent of bone removal, with a particular focus on the SAP.

A New Piece of the Puzzle to Understand Cervical Sagittal Alignment: Utilizing a Novel Angle δ to Describe the Relationship among T1 Vertebral Body Slope, Cervical Lordosis, and Cervical Sagittal Alignment

Neurosurgery 2019 DOI:10.1093/neuros/nyz088

Cervical alignment has become increasingly important in the planning of spine surgery. A relationship between the slope of T1 (T1S), the cervical lordosis (CL), and the overall cervical sagittal vertical axis (cSVA) has previously been demonstrated, but the exact nature of this relationship is poorly understood. In this study, we derive theoretical and empirical equations to better understand how T1S and CL affect cSVA. The first equation was developed on a theoretical basis using inherent trigonometric relationships of the cervical spine. By treating the cervical spine as the arc of a circumference, and by taking into account the cervical height (CH), the geometric relationship between theT1S, CL, and cSVA was described via a trigonometric identity utilizing a novel angle δ subtended by the CH and cSVA (δ = T1S-CL/2). The second equation was developed on an empiric basis by performing a multiple linear regression on data obtained from a retrospective review of a large multicenter deformity database. The theoretical equation determined that the value of cSVA could be expressed as: cSVA = CH ∗ tan(π/180 ∗ (T 1S −CL/2)) . The empirical equation determined that value of cSVA could be expressed as: cSVA = (1.1 ∗ T 1) −(0.43 ∗ CL) + 6.69. In both, the sagittal alignment of the head over the shoulders is directly proportional to the T1S and inversely proportional to CL/2. These 2 equations may allow surgeons to better understand how the CL compensates for the T1S, to accurately predict the postoperative cSVA, and to customize cervical interbody grafts by taking into consideration each individual patient’s specific cervical spine parameters.

Posterior foraminotomy versus anterior decompression and fusion in patients with cervical degenerative disc disease with radiculopathy

J Neurosurg Spine 32:344–352, 2020

The long-term efficacy of posterior foraminotomy compared with anterior cervical decompression and fusion (ACDF) for the treatment of degenerative disc disease with radiculopathy has not been previously investigated in a population-based cohort.

METHODS All patients in the national Swedish Spine Register (Swespine) from January 1, 2006, until November 15, 2017, with cervical degenerative disc disease and radiculopathy were assessed. Using propensity score matching, patients treated with posterior foraminotomy were compared with those undergoing ACDF. The primary outcome measure was the Neck Disability Index (NDI), a patient-reported outcome score ranging from 0% to 100%, with higher scores indicating greater disability. A minimal clinically important difference was defined as > 15%. Secondary outcomes were assessed with additional patient-reported outcome measures (PROMs).

RESULTS A total of 4368 patients (2136/2232 women/men) met the inclusion criteria. Posterior foraminotomy was performed in 647 patients, and 3721 patients underwent ACDF. After meticulous propensity score matching, 570 patients with a mean age of 54 years remained in each group. Both groups had substantial decreases in their NDI scores; however, after 5 years, the difference was not significant (2.3%, 95% CI −4.1% to 8.4%; p = 0.48) between the groups. There were no significant differences between the groups in EQ-5D or visual analog scale (VAS) for neck and arm scores. The secondary surgeries on the index level due to restenosis were more frequent in the foraminotomy group (6/100 patients vs 1/100), but on the adjacent segments there was no difference between groups (2/100).

CONCLUSIONS In patients with cervical degenerative disc disease and radiculopathy, both groups demonstrated clinical improvements at the 5-year follow-up that were comparable and did not achieve a clinically important difference from one another, even though the reoperation rate favored the ACDF group. This study design obtains population-based results, which are generalizable.

Cost of Readmissions Following Anterior Cervical Discectomy and Fusion

Neurosurgery DOI:10.1093/neuros/nyz443

Postoperative readmissions are a significant driver of variation in bundled care costs associated with cervical spine surgery.

OBJECTIVE: To determine the factors predicting the cost of readmission episodes following elective anterior cervical discectomy and fusion (ACDF).

METHODS: We queried the Healthcare Cost and Utilization Project Nationwide Readmissions Database for patients undergoing elective ACDF during 2012 to 2015. Multivariable linear regression was performed to establish the factors associated with the cost of each 30-/90-d readmission episode.

RESULTS: A total of 139 877 and 113 418 patients met inclusion criteria for the evaluation of 30- and 90-d readmissions, respectively. Among these, the national rates of 30- and 90-d readmission after an elective ACDF were 3% and 6%, respectively. The median cost of a 30- and 90-d readmission episode was $6727 (IQR: $3844-$13 529) and $8507 (IQR: $4567- $17 460), respectively. Relative predictor importance analysis revealed that the number of procedures at index admission (IA), length of stay at IA, and time elapsed between index surgical admission and readmission were the top predictors of both 30- and 90-d readmission costs (all P < .001). Although cervical myelopathy accounted for only 3.6% of all 30-d readmissions, it accounted for the largest share (8%) of 30-d readmission costs.

CONCLUSION: In this analysis from a national all-payer database, we determined the factors associated with the cost of readmissions following elective ACDF. These results are important in assisting policymakers and payers with a better risk adjustment in bundled care payment systems and for surgeons in implementing readmission cost-reduction efforts.

Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion With Expandable Lordotic Devices

Neurosurgery, Volume 86, Issue 2, February 2020, Pages E147–E155

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is a well-accepted procedure for the treatment of degenerative lumbar disease. However, its ability to restore lumbar lordosis has been limited. Development of expandable lordotic interbody devices has challenged this limitation, furthering the scope ofminimally invasive surgery.

OBJECTIVE: To evaluate the radiographic and clinical effects of expandable lordotic interbody devices placed through an MIS-TLIF approach.

METHODS: We conducted a retrospective review of 32 1-level and 18 2-level MIS-TLIFs performed using lordotic expandable interbody devices. Lumbar radiographic measurements, Oswestry Disability Index scores (ODI), and Visual Analogue Scale scores (VAS)were obtained at preoperative, 6 wk follow up, and last follow up time points. Last follow up occurred at a mean of 11.5 ± 7.6 mo (mean ± SD).

RESULTS: At 6-wk follow-up, segmental lordosis, disc height, and foraminal height increased by an average of 3.4◦, 6.4 mm, and 4.4 mm, respectively. Only the 2-level group showed a significant increase in lumbar lordosis of 5.8◦. No significant changes occurred in sacral slope, pelvic tilt, or pelvic incidence. Average ODI and VAS decreased by −12.0 and −4.5, respectively. Postoperative lumbar lordosis inversely correlated with preoperative lordosis in patients with an initial Pelvic Incidence to Lumbar Lordosis mismatch (PI-LL) of >10◦, (r=−0.5, P = .009).

CONCLUSION: When applied across 2-levels, MIS-TLIF using expandable lordotic interbody devices produced a significant increase in lumbar lordosis. Preoperative lumbar lordosis was found to be a predictor of postoperative lumbar lordotic change in patients with sagittal imbalance.

Long-term outcomes of high-dose single-fraction radiosurgery for chordomas of the spine and sacrum

J Neurosurg Spine 32:79–88, 2020

The current treatment of chordomas is associated with significant morbidity, high rates of local recurrence, and the potential for metastases. Stereotactic radiosurgery (SRS) as a primary treatment could reduce the need for en bloc resection to achieve wide or marginal margins. Spinal SRS outcomes support the exploration of SRS’s role in the durable control of these conventionally radioresistant tumors. The goal of the study was to evaluate outcomes of patients with primary chordomas treated with spinal SRS alone or in combination with surgery.

METHODS Clinical records were reviewed for outcomes of patients with primary chordomas of the mobile spine and sacrum who underwent single-fraction SRS between 2006 and 2017. Radiographic local recurrence-free survival (LRFS), overall survival (OS), symptom response, and toxicity were assessed in relation to the extent of surgery.

RESULTS In total, 35 patients with de novo chordomas of the mobile spine (n = 17) and sacrum (n = 18) received SRS and had a median post-SRS follow-up duration of 38.8 months (range 2.0–122.9 months). The median planning target volume dose was a 24-Gy single fraction (range 18–24 Gy). Overall, 12 patients (34%) underwent definitive SRS and 23 patients (66%) underwent surgery and either neoadjuvant or postoperative adjuvant SRS. Definitive SRS was selectively used to treat both sacral (n = 7) and mobile spine (n = 5) chordomas. Surgical strategies for the mobile spine were either intralesional, gross-total resection (n = 5) or separation surgery (n = 7) and for the sacrum en bloc sacrectomy (n = 11). The 3- and 5-year LRFS rates were 86.2% and 80.5%, respectively. Among 32 patients (91%) receiving 24-Gy radiation doses, the 3- and 5-year LRFS rates were 96.3% and 89.9%, respectively. The 3- and 5-year OS rates were 90.0% and 84.3%, respectively. The symptom response rate to treatment was 88% for pain and radiculopathy. The extent or type of surgery was not associated with LRFS, OS, or symptom response rates (p > 0.05), but en bloc resection was associated with higher surgical toxicity, as measured using the Common Terminology Criteria for Adverse Events (version 5.0) classification tool, than epidural decompression and curettage/intralesional resection (p = 0.03). The long-term rate of toxicity ≥ grade 2 was 31%, including 20% grade 3 tissue necrosis, recurrent laryngeal nerve palsy, myelopathy, fracture, and secondary malignancy.

CONCLUSIONS High-dose spinal SRS offers the chance for durable radiological control and effective symptom relief with acceptable toxicity in patients with primary chordomas as either a definitive or adjuvant therapy.

 

 

Perioperative complications with multilevel anterior and posterior cervical decompression and fusion

J Neurosurg Spine 32:9–14, 2020

Cervical spondylotic myelopathy (CSM) is a progressive degenerative pathology that frequently affects older individuals and causes spinal cord compression with symptoms of neck pain, radiculopathy, and weakness. Anterior decompression and fusion is the primary intervention to prevent neurological deterioration; however, in severe cases, circumferential decompression and fusion is necessary. Published data regarding perioperative morbidity associated with these complex operations are scarce. In this study, the authors sought to add to this important body of literature by documenting a large single-surgeon experience of single-session circumferential cervical decompression and fusion.

METHODS A retrospective analysis was performed to identify intended single-stage anterior-posterior or posterioranterior- posterior cervical spine decompression and fusion surgeries performed by the primary surgeon (V.C.T.) at Rush University Medical Center between 2009 and 2016. Cases in which true anterior-posterior cervical decompression and fusion was not performed (i.e., those involving anterior-only, posterior-only, or delayed circumferential fusion) were excluded from analysis. Data including standard patient demographic information, comorbidities, previous surgeries, and intraoperative course, along with postoperative outcomes and complications, were collected and analyzed. Perioperative morbidity was recorded during the 90 days following surgery.

RESULTS Seventy-two patients (29 male and 43 female, mean age 57.6 years) were included in the study. Fourteen patients (19.4%) were active smokers, and 56.9% had hypertension, the most common comorbidity. The most common clinical presentation was neck pain in 57 patients (79.2%). Twenty-three patients (31.9%) had myelopathy, and 32 patients (44.4%) had undergone prior cervical spine surgery. Average blood loss was 613 ml. Injury to the vertebral artery was encountered in 1 patient (1.4%). Recurrent laryngeal nerve palsy was observed in 2 patients (2.8%). Two patients (2.8%) had transient unilateral hand grip weakness. There were no permanent neurological deficits. Dysphagia was encountered in 45 patients (62.5%) postoperatively, with 23 (32%) requiring nasogastric parenteral nutrition and 9 (12.5%) patients ultimately undergoing percutaneous endoscopic gastrostomy (PEG) placement. Nine of the 72 patients required a tracheostomy. The incidence of pneumonia was 6.9% (5 patients) overall, and 2 of these patients were in the tracheostomy group. Superficial wound infections occurred in 4 patients (5.6%). Perioperative death occurred in 1 patient. Reoperation was necessary in 10 patients (13.9%). Major perioperative complications (permanent neurological deficit, vascular injury, tracheostomy, PEG tube, stroke, or death) occurred in 30.6% of patients. The risk of minor perioperative complications (temporary deficit, dysphagia, deep vein thrombosis, pulmonary embolism, urinary tract infection, pneumonia, or wound infection) was 80.6%.

CONCLUSIONS Single-session anterior-posterior cervical decompression and fusion is an inherently morbid operation required in select patients with cervical spondylotic myelopathy. In this large single-surgeon series, there was a major perioperative complication risk of 30.6% and minor perioperative complication risk of 80.6%. This overall elevated risk for postoperative complications must be carefully considered and discussed with the patient preoperatively. In some situations, shared decision making may lead to the conclusion that a procedure of lesser magnitude may be more appropriate.

Lumbar disc extrusions reduce faster than bulging discs due to an active role of macrophages in sciatica

Acta Neurochirurgica (2020) 162:79–85

This retrospective observational histological study aims to associate the size and type of disc herniation with the degree of macrophage infiltration in disc material retrieved during disc surgery in patients with sciatica.

Methods Disc tissue of 119 sciatica patients was embedded in paraffin and stained with hematoxylin and CD68. Tissue samples were categorized as mild (0–10/cm2), moderate (10–100/cm2), and considerable (> 100/cm2) macrophage infiltration. All 119 patients received an MRI at baseline, and 108 received a follow-up MRI at 1-year. MRIs were reviewed for the size and type of the disc herniations, and for Modic changes in the vertebral endplates.

Results Baseline characteristics and duration of symptoms before surgery were comparable in all macrophage infiltration groups. The degree of macrophage infiltration was not associated with herniation size at baseline, but significantly associated with reduction of size of the herniated disc at 1-year post surgery. Moreover, the degree of macrophage infiltration was higher in extrusion in comparison with bulging (protrusion) of the disc. Results were comparable in patients with and without Modic changes.

Conclusion Macrophage infiltration was positively associated with an extruded type of disc herniation as well as the extent of reduction of the herniated disc during 1-year follow-up in patients with sciatica. This is an indication that the macrophages play an active role in reducing herniated discs. An extruded disc herniation has a larger surface for the macrophages to adhere to, which leads to more size reduction.

Safety of Outpatient Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-Analysis

Neurosurgery 86:30–45, 2020

Anterior cervical discectomy and fusion (ACDF) is being increasingly offered on an outpatient basis. However, the safety profile of outpatient ACDF remains poorly defined.

OBJECTIVE: To review the medical literature on the safety of outpatient ACDF.

METHODS: We systematically reviewed the literature for articles published before April 1, 2018, describing outpatient ACDF and associated complications, including incidence of reoperation, stroke, thrombolytic events, dysphagia, hematoma, and mortality. A random-effects analysis was performed comparing complications between the inpatient and outpatient groups.

RESULTS: We identified 21 articles that satisfied the selection criteria, of which 15 were comparative studies. Most of the existing studies were retrospective, with a lack of level I or II studies on this topic. We found no statistically significant difference between inpatient and outpatient ACDF in overall complications, incidence of stroke, thrombolytic events, dysphagia, and hematoma development. However, patients undergoing outpatient ACDF had lower reported reoperation rates (P < .001), mortality (P < .001), and hospitalization duration (P < .001).

CONCLUSION: Our meta-analysis indicates that there is a lack of high level of evidence studies regarding the safety of outpatient ACDF. However, the existing literature suggests that outpatient ACDF can be safe, with low complication rates comparable to inpatient ACDF in well-selected patients. Patients with advanced age and comorbidities such as obesity and significant myelopathy are likely not suitable for outpatient ACDF. Spine surgeons must carefully evaluate each patient to decide whether outpatient ACDF is a safe option. Higher quality, large prospective randomized control trials are needed to accurately demonstrate the safety profile of outpatient ACDF.

Stem cell injections for axial back pain: a systematic review of associated risks and complications with a case illustration of diffuse hyperplastic gliosis resulting in cauda equina syndrome

J Neurosurg Spine 31:906–913, 2019

Axial low-back pain is a disease of epidemic proportions that exerts a heavy global toll on the active workforce and results in more than half a trillion dollars in annual costs. Stem cell injections are being increasingly advertised as a restorative solution for various degenerative diseases and are becoming more affordable and attainable by the public. There have been multiple reports in the media of these injections being easily available abroad outside of clinical trials, but scientific evidence supporting them remains scarce. The authors present a case of a serious complication after a stem cell injection for back pain and provide a systematic review of the literature of the efficacy of this treatment as well as the associated risks and complications.

METHODS A systematic review of the literature was performed using the PubMed, Google Scholar, and Scopus online electronic databases to identify articles reporting stem cell injections for axial back pain in accordance with the PRISMA guidelines. The primary focus was on outcomes and complications. A case of glial hyperplasia of the roots of the cauda equina directly related to stem cell injections performed abroad is also reported.

RESULTS The authors identified 14 publications (including a total of 147 patients) that met the search criteria. Three of the articles presented data for the same patient population with different durations of follow-up and were thus analyzed as a single study, reducing the total number of studies to 12. In these 12 studies, follow-up periods ranged from 6 months to 6 years, with 50% having a follow-up period of 1 year or less. Most studies reported favorable outcomes, although 36% used subjective measures. There was a tendency for pain relief to wane after 6 months to 2 years, with patients seeking a surgical solution. Only 1 study was a randomized controlled trial (RCT).

CONCLUSIONS There are still insufficient data to support stem cell injections for back pain. Additional RCTs with longterm follow-up are necessary before statements can be made regarding the efficacy and safety.

 

Complications Associated with Surgery for Thoracic Disc Herniation: A Systematic Review and Network Meta-Analysis

World Neurosurgery Volume 132, December 2019, Pages 334-342

A systematic review and network meta-analysis (Prospero ID CRD42018106936) were performed.

Objective: The selection of the appropriate surgical approach for the management of thoracic disc herniation (TDH) is often challenging because of the frequency and variability of the associated complications. We evaluated the safety of the surgical approaches for TDH by estimating the mortality (Q1) and morbidity (Q2), and frequency of the most common complications (Q3).

Methods: We searched the medical literature for randomized controlled trials and observational studies reporting on the management of TDH. Postoperative complications were the outcome of interest. The absolute and relative risk estimates, along with the rank probability scores, were estimated for each approach, through a network meta-analysis. The results were read in the light of the quality of the available evidence.

Results: Fifteen studies with a total of 1036 patients fulfilled our eligibility criteria. Three deaths were reported. The overall morbidity was as high as 29%, largely attributed to medical (21%; 95% confidence interval [CI], 10%–38%), surgical site (11%; 95% CI, 5%–22%), cerebrospinal fluid–related (8%; 95% CI, 3%–8%), and neurologic complications (5%; 95% CI, 1%–24%). The anterior and lateral approaches were associated with a higher risk for medical and surgical complications compared with the posterolateral approach.

Conclusions: Surgery for TDH is associated with minimal mortality but significant morbidity, with large variations among the available approaches. An understanding of the perioperative complications rates is important to develop complication avoidance strategies and to aid accurate patient-to-doctor communication.

Review of Risks and Complications of Extreme Lateral Interbody Fusion (XLIF)

Surg Neurol Int 2019;10:237

Extreme lateral interbody fusions (XLIF) and Minimally Invasive (MIS) XLIF were developed to limit the vascular injuries associated with anterior lumbar interbody fusion (ALIF), and minimize the muscular/ soft tissue trauma attributed to transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF), and posterolateral lumbar fusion (PLF).

Methods: Nevertheless, XLIF/MIS XLIF pose significant additional risks and complications that include; multiple nerve injuries (e.g. lumbar plexus, ilioinguinal, iliohypogastric, genitofemoral, lateral femoral cutaneous, and subcostals (to the anterior abdominal muscles: abdominal oblique), and sympathectomy), major vascular injuries, bowel perforations/postoperative ileus, seromas, pseudarthrosis, subsidence, and reoperations.

Results: The risks of neural injury with XLIF/MIS XLIF (up to 30-40%) are substantially higher than for TLIF, PLIF, PLF, and ALIF. These neural injuries included: lumbar plexus injuries (13.28%); new sensory deficits (0-75% (21.7%-40%); permanent 62.5%); motor deficits (0.7-33.6%-40%); iliopsoas weakness (9%-31%: permanent 5%), anterior thigh/groin pain (12.5-34%), and sympathectomy (4%-12%). Additional non-neurological complications included; subsidence (10.3%-13.8%), major vascular injuries (0.4%), bowel perforations, recurrent seroma, malpositioning of the XLIF cages, a 45% risk of cage-overhang, pseudarthrosis (7.5%), and failure to adequately decompress stenosis. In one study, reviewing 20 publications and involving 1080 XLIF patients, the authors observed “Most (XLIF) studies are limited by study design, sample size, and potential conflicts of interest.”

Conclusion: Many new neurological deficits and other adverse events/complications are attributed to MIS XLIF/ XLIF. Shouldn’t these significant risk factors be carefully taken into consideration before choosing to perform MIS XLIF/XLIF?

Midline lumbar interbody fusion (MIDLIF) with cortical screws

Acta Neurochirurgica (2019) 161:2415–2420

A variety of surgical techniques can be used to achieve lumbar spinal fusion for management of degenerative conditions. Transforaminal lumbar interbody fusion (TLIF) is the most popular technique; however, midline lumbar interbody fusion (MIDLIF) is a valid alternative to the more traditional pedicle screw trajectory with potential advantages. The aim of this study is to evaluate the clinical outcomes from a cohort of patients submitted to MIDLIF in a single hospital during the surgical team’s initial learning period.

Methods The first 30 consecutive patients who underwent single- or two-level MIDLIF surgery for lumbar degenerative disease were included in this retrospective study. Patients’ demographics, surgical data, length of hospitalisation, and perioperative complications were analysed. Preoperative and postoperative radiographic parameters were obtained. Validated questionnaires, Core Outcome Measure Index for the back, Euro-QoL 5-Dimensional Questionnaire, and Oswestry Disability Index, were used for clinical assessment.

Results Mean surgery time was 278.53 ± 82.16 min and mean hospitalisation time was 6.17 ± 3.51 days. Six patients experienced complications, four of which being dural tears with no consequences, and two required reoperations during the mean follow-up of 25.23 ± 9.74 months. Preoperative and postoperative radiological parameters did not demonstrate significant differences. All clinical parameters significantly improved after surgery (p < 0.001). A complexity score was developed to more accurately compare the different procedures, and it strongly correlated with surgery duration (r = 0.719, p < 0.001). Furthermore, a moderate correlation was found between a developed Duration Index and the patient’s order number (r = − 0.539, p = 0.002).

Conclusions In our initial experience, MIDLIF showed to be effective in significantly improving the patients’ functional status, pain scores, and quality of life. The technique seems safe, with an acceptably low complication rate. Hence, MIDLIF can be considered as a promising alternative to more traditional TLIF and PLIF techniques even at the beginning of the learning curve.

Total uncinectomy of the cervical spine with an osteotome

J Neurosurg Spine 31:831–834, 2019

Total uncinate process resection or uncinectomy is often required in the setting of severe foraminal stenosis or cervical kyphosis correction. The proximity of the uncus to the vertebral artery, nerve root, and spinal cord makes this a challenging undertaking. Use of a high-speed burr or ultrasonic bone dissector can be associated with direct injury to the vertebral artery and thermal injury to the surrounding structures. The use of an osteotome is a safe and efficient method of uncinectomy.

Here the authors describe their technique, which is illustrated with an intraoperative video.

Outcomes of endoscopic discectomy compared with open microdiscectomy and tubular microdiscectomy for lumbar disc herniations: a meta-analysis

J Neurosurg Spine 31:802–815, 2019

Endoscopic discectomy (ED) has been advocated as a less-invasive alternative to open microdiscectomy (OM) and tubular microdiscectomy (TM) for lumbar disc herniations, with the potential to decrease postoperative pain and shorten recovery times. Large-scale, objective comparisons of outcomes between ED, OM, and TM, however, are lacking. The authors’ objective in this study was to conduct a meta-analysis comparing outcomes of ED, OM, and TM.

METHODS The PubMed database was searched for articles published as of February 1, 2019, for comparative studies reporting outcomes of some combination of ED, OM, and TM. A meta-analysis of outcome parameters was performed assuming random effects.

RESULTS Twenty-six studies describing the outcomes of 2577 patients were included. Estimated blood loss was significantly higher with OM than with both TM (p = 0.01) and ED (p < 0.00001). Length of stay was significantly longer with OM than with ED (p < 0.00001). Return to work time was significantly longer in OM than with ED (p = 0.001). Postoperative leg (p = 0.02) and back (p = 0.01) VAS scores, and Oswestry Disability Index scores (p = 0.006) at latest follow-up were significantly higher for OM than for ED. Serum creatine phosphokinase (p = 0.02) and C-reactive protein (p < 0.00001) levels on postoperative day 1 were significantly higher with OM than with ED.

CONCLUSIONS Outcomes of TM and OM for lumbar disc herniations are largely equivalent. While this analysis demonstrated that several clinical variables were significantly improved in patients undergoing ED when compared with OM, the magnitude of many of these differences was small and of uncertain clinical relevance, and several of the included studies were retrospective and subject to a high risk of bias. Further high-quality prospective studies are needed before definitive conclusions can be drawn regarding the comparative efficacy of the various surgical treatments for lumbar disc herniations.

 

Heterotopic ossification and radiographic adjacent-segment disease after cervical disc arthroplasty

J Neurosurg Spine 31:660–669, 2019

Cervical disc arthroplasty (CDA) is an accepted motion-sparing technique associated with favorable patient outcomes. However, heterotopic ossification (HO) and adjacent-segment degeneration are poorly understood adverse events that can be observed after CDA. The purpose of this study was to retrospectively examine 1) the effect of the residual exposed endplate (REE) on HO, and 2) identify risk factors predicting radiographic adjacent-segment disease (rASD) in a consecutive cohort of CDA patients.

METHODS A retrospective cohort study was performed on consecutive adult patients (≥ 18 years) who underwent 1- or 2-level CDA at the University of Calgary between 2002 and 2015 with > 1-year follow-up. REE was calculated by subtracting the anteroposterior (AP) diameter of the arthroplasty device from the native AP endplate diameter measured on lateral radiographs. HO was graded using the McAfee classification (low grade, 0–2; high grade, 3 and 4). Change in AP endplate diameter over time was measured at the index and adjacent levels to indicate progressive rASD.

RESULTS Forty-five patients (58 levels) underwent CDA during the study period. The mean age was 46 years (SD 10 years). Twenty-six patients (58%) were male. The median follow-up was 29 months (IQR 42 months). Thirty-three patients (73%) underwent 1-level CDA. High-grade HO developed at 19 levels (33%). The mean REE was 2.4 mm in the high-grade HO group and 1.6 mm in the low-grade HO group (p = 0.02). On multivariable analysis, patients with REE > 2 mm had a 4.5-times-higher odds of developing high-grade HO (p = 0.02) than patients with REE ≤ 2 mm. No significant relationship was observed between the type of artificial disc and the development of high-grade HO (p = 0.1). RASD was more likely to develop in the lower cervical spine (p = 0.001) and increased with time (p < 0.001). The presence of an artificial disc was highly protective against degenerative changes at the index level of operation (p < 0.001) but did not influence degeneration in the adjacent segments.

CONCLUSIONS In patients undergoing CDA, high-grade HO was predicted by REE. Therefore, maximizing the implant-endplate interface may help to reduce high-grade HO and preserve motion. RASD increases in an obligatory manner following CDA and is highly linked to specific levels (e.g., C6–7) rather than the presence or absence of an adjacent arthroplasty device. The presence of an artificial disc is, however, protective against further degenerative change at the index level of operation.

Surgical correction of severe adult lumbar scoliosis (major curves ≥ 75°): retrospective analysis with minimum 2-year follow-up

J Neurosurg Spine 31:548–561, 2019

Prior reports have demonstrated the efficacy of surgical correction for adult lumbar scoliosis. Many of these reports focused on mild to moderate scoliosis. The authors’ objective was to report their experience and to assess outcomes and complications after deformity correction for severe adult scoliosis.

METHODS The authors retrospectively analyzed consecutive adult scoliosis patients with major thoracolumbar/lumbar (TL/L) curves ≥ 75° who underwent deformity correction at their institution. Those eligible with a minimum 2 years of follow-up were included. Demographic, surgical, coronal and sagittal plane radiographic measurements, and healthrelated quality of life (HRQL) scores were analyzed.

RESULTS Among 26 potentially eligible patients, 22 (85%) had a minimum 2 years of follow-up (range 24–89 months) and were included in the study (mean age 57 ± 11 years; 91% women). The cohort comprised 16 (73%), 4 (18%), and 2 (9%) patients with adult idiopathic scoliosis, de novo degenerative scoliosis, and iatrogenic scoliosis, respectively. The surgical approach was posterior-only and multistage anterior-posterior in 18 (82%) and 4 (18%) patients, respectively. Three-column osteotomy was performed in 5 (23%) patients. Transforaminal and anterior lumbar interbody fusion were performed in 14 (64%) and 4 (18%) patients, respectively. All patients had sacropelvic fixation with uppermost instrumented vertebra in the lower thoracic spine (46% [10/22]) versus upper thoracic spine (55% [12/22]). The mean fusion length was 14 ± 3 levels. Preoperative major TL/L and lumbosacral fractional (L4–S1) curves were corrected from 83° ± 8° to 28° ± 13° (p < 0.001) and 34° ± 8° to 13° ± 6° (p < 0.001), respectively. Global coronal and sagittal balance significantly improved from 5 ± 4 cm to 1 ± 1 cm (p = 0.001) and 9 ± 8 cm to 2 ± 3 cm (p < 0.001), respectively. Pelvic tilt significantly improved from 33° ± 9° to 23° ± 10° (p < 0.001). Significant improvement in HRQL measures included the following: Scoliosis Research Society (SRS) pain score (p = 0.009), SRS appearance score (p = 0.004), and SF-12/ SF-36 physical component summary (PCS) score (p = 0.026). Transient and persistent neurological deficits occurred in 8 (36%) and 2 (9%) patients, respectively. Rod fracture/pseudarthrosis occurred in 6 (27%) patients (supplemental rods were utilized more recently in 23%). Revisions were performed in 7 (32%) patients.

CONCLUSIONS In this single-center surgical series for severe adult scoliosis (major curves ≥ 75°), a posterior-only or multistage anterior-posterior approach provided major curve correction of 66% and significant improvements in global coronal and sagittal spinopelvic alignment. Significant improvements were also demonstrated in HRQL measures (SRS pain, SRS appearance, and SF-12/SF-36 PCS). Complications and revisions were comparable to those of other reports involving less severe scoliosis. The results of this study warrant future prospective multicenter studies to further delineate outcomes and complication risks for severe adult scoliosis correction.