Predictors of Clinical Failure after Endoscopic Lumbar Spine Surgery During the Initial Learning Curve.

OBJECTIVE: This study aims to identify clinical factors that may predict failed endoscopic lumbar spine surgery to guide surgeons with patient selection during the initial learning curve. METHODS: This is an Australasian prospective analysis of the first 105 patients to undergo lumbar endoscopic spine decompression by 3 surgeons. Modified MacNab outcomes, visual analog scale (VAS) and Oswestry Disability Index (ODI) scores were utilized to evaluate clinical outcomes at 6 months postoperatively. Descriptive statistics and ANOVA t tests were performed to measure statistically significant (P < 0.05) associations between variables using GraphPad Prism v10. RESULTS: Patients undergoing endoscopic lumbar surgery via an interlaminar or transforaminal approach have overall good/excellent modified MacNab outcomes and a significant reduction in postoperative VAS and ODI scores. Regardless of the anatomic location of disc herniations, good/excellent modified MacNab outcomes and significant reductions in VAS and ODI were reported post-operatively, however, not in patients with calcified disc herniations. Patients with central and foraminal stenosis overall reported poor/fair modified MacNab outcomes, however, there were significant reductions in VAS and ODI scores postoperatively. Patients with subarticular stenosis or an associated spondylolisthesis reported good/excellent modified MacNab outcomes and significant reductions in VAS and ODI scores postoperatively. Patients with disc herniation and concurrent degenerative stenosis had generally poor/fair modified MacNab outcomes. CONCLUSIONS: The outcomes of endoscopic spine surgery are encouraging with low complication and reoperation rates. However, patients with calcified disc herniations, central canal stenosis, or disc herniation with concurrent degenerative stenosis present challenges during the initial learning curve and may benefit from traditional open or other minimally invasive techniques.

A tale of two robots: Operating times and learning curves in robot-assisted lumbar fusion.

Robotic assistance technologies are being incorporated into minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) to minimize radiation exposure to the patient and operating staff. However, they introduce new issues including increased operating time and difficult incorporation into surgical workflow. This study, conducted with 42 patients under the care of one neurosurgeon in Sydney, Australia, investigates the operating time increase with three different robotic modalities, and the learning curves they pose to the surgeon. Between the comparable modalities of freehand MIS-TLIF and Mazor Renaissance® CT to Fluoro, there was a significant increase in time from patient draping to insertion of the final K-wire (p = 0.0019), and a non-significant increase in time per K-wire (p = 0.55) using Mazor Renaissance®. Comparing the ROSA® and Mazor Renaissance® Scan and Plan, there were significant increases in drape to final K-wire time and time per K-wire using ROSA® assistance (p = 0.000068 and p = 0.011). ROSA® also had a steeper learning curve compared to both Mazor Renaissance® modalities, which were similar. Our study shows that Mazor Renaissance® modalities are superior to ROSA® in minimizing extra operating time, and also have easier learning curves; however, both modalities increase operating time compared with freehand MIS-TLIF. This study, to our knowledge, is the first to compare multiple robotic techniques in MIS-TLIF. Though these results highlight important differences between robotic modalities that are crucial for spinal surgeons to understand, the low sample size and variability in data reveal the need for larger, multi-centre studies in this field.

Outcomes of direct lateral interbody fusion (DLIF) in an Australian cohort.

BACKGROUND: Direct lateral interbody fusion (DLIF) mitigates many of the vascular complications and bony resections associated with other interbody fusion techniques. However, there are concerns regarding postoperative neural complications and that indirect decompression of the foramen has not been consistently demonstrated. This study prospectively assessed the clinical and radiological outcomes and the complication rates of the DLIF approach. METHODS: A prospective review was conducted of the first 50 consecutive DLIF cases of a single neurosurgeon between 2010 and 2014. Clinical outcomes were assessed using Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) and Roland Morris Disability Questionnaire (RMDQ) surveys. Radiological outcomes, including spondylolisthesis, disc height, local disc angle, lumbar lordosis and foraminal height and width, were measured using Surgimap Spine software at the preoperative, 6 weeks, 6 months, and 12 months postoperative follow-up. Complication rates were also reported. RESULTS: A total of 50 patients (84 levels) were treated with DLIF. The mean patient age was 68.2±9.8 years and 62.0% were female. At latest follow-up, mean VAS pain score improved from 7.7±1.5 to 1.9±0.9 (P<0.0001), mean ODI improved from 42.1±14.5 to 16.9±6.7 (P<0.0001) and mean RMDQ score improved from 12.1±5.2 to 6.2±4.7 (P<0.0001). Mean spondylolisthesis reduced from 7.5%±6.5% to 1.3%±1.1% at 6 weeks (P<0.0001), 0.95%±0.74% at 6 months (P<0.0001) and recurred to 1.9%±1.7% at 12 months postoperatively (P=0.0006). Mean anterior disc height improved from 7.3±3.2 to 11.6±2.5 mm at 6 weeks (P<0.0001), 12.2±3.3 mm at 6 months (P<0.0001) and 9.8±2.1 mm at 12 months (P=0.0032) postoperatively. Mean posterior disc height improved from 4.4±2.0 to 6.8±2.1 mm at 6 weeks (P<0.0001), 6.6±2.5 mm at 6 months (P=0.0003), and 5.9±1.4 mm at 12 months (P=0.0039) postoperatively. Mean local disc angle improved from 7.0°±3.7° to 9.2°±3.3° at 6 weeks (P=0.0072), 10.4°±3.9° at 6 months (P=0.0013) and 8.2°±2.9° at 12 months (P=0.2487) postoperatively. No significant postoperative changes in lumbar lordosis were observed. Mean foraminal height improved from 18.3±3.5 to 21.5±3.9 mm at 6 weeks (P=0.0004), 20.6±3.4 mm at 6 months (P=0.0266), and 18.7±1.9 mm at 12 months (P=0.8021) postoperatively. Mean foraminal width improved from 7.9±2.0 to 10.2±2.8 mm at 6 weeks (P=0.0001), 9.4±2.6 mm at 6 months (P=0.0219) and 8.3±1.6 mm at 12 months (P=0.5734) postoperatively. Fusion rate at 6 and 12 months was 62.2% and 89.2%, respectively. A total of 6 patients (12%) had postoperative complications. Three patients (6%) had pain-related psoas muscle weakness and 3 patients (6%) had sensory neural complications that had resolved entirely by 8 and 16 weeks postoperatively, respectively. CONCLUSIONS: The study provides encouraging short and medium-term clinical and radiological results for DLIF. In this patient series, there was a low complication rate with no permanent neural injury reported.

Craniotomy Versus Decompressive Craniectomy for Acute Subdural Hematoma: Systematic Review and Meta-Analysis.

BACKGROUND: Acute subdural hematoma (SDH) is a major cause of morbidity after severe traumatic brain injury. Surgical evacuation of the hematoma, either via craniotomy or craniectomy, is the mainstay of treatment in patients with progressive neurologic deficits or significant mass effect. However, the decision to perform either procedure remains controversial. METHODS: A literature search using major online databases and a manual search of references on the topic of craniotomy and craniectomy for evacuation of subdural hematoma until September 2016 was performed. The outcome variables were analyzed which included residual SDH, revision rate, and clinical outcome. RESULTS: Six comparison studies, with a total number of 2006 craniotomy and 451 craniectomy patients, fulfilled the inclusion criteria. Patients who underwent craniectomy scored significantly lower on the Glasgow Coma Scale at the time of initial presentation. Postoperatively, the rate of residual SDH was significantly lower in the craniectomy group than the craniotomy group (P = 0.004), with no difference in the revision rate. The odds of a poor outcome at follow-up was found to be lower in the craniotomy group (50.1% vs. 60.1%, respectively; P = 0.004). Similarly, mortality rates was lower in the craniotomy group than the craniectomy group (P = 0.004). CONCLUSIONS: The safety and efficacy of craniotomy versus decompressive craniectomy in treatment of acute SDH remain controversial. In this study, craniectomy was associated with worse clinical presentation and postoperative outcome compared with craniotomy. However, craniectomy was associated with lower rate of residual SDH after treatment.

Laminectomy and fusion vs laminoplasty for multi-level cervical myelopathy: a systematic review and meta-analysis.

BACKGROUND: Surgical approaches for multi-level cervical spondylotic myelopathy (CSM) include posterior cervical surgery via laminectomy and fusion (LF) or expansive laminoplasty (EL). The relative benefits and risks of either approach in terms of clinical outcomes and complications are not well established. A systematic review and meta-analysis was conducted to address this topic. METHODS: Electronic searches were performed using six databases from their inception to January 2016, identifying all relevant randomized controlled trials (RCTs) and non-RCTs comparing LF vs EL for multi-level cervical myelopathy. Data was extracted and analyzed according to predefined endpoints. RESULTS: From 10 included studies, there were 335 patients who underwent LF compared to 320 patients who underwent EL. There was no significant difference found postoperatively between LF and EL groups in terms of postoperative JOA (P = 0.39), VAS neck pain (P = 0.93), postoperative CCI (P = 0.32) and Nurich grade (P = 0.42). The total complication rate was higher for LF compared to EL (26.4 vs 15.4 %, RR 1.77, 95 % CI 1.10, 2.85, I 2 = 34 %, P = 0.02). Reoperation rate was found to be similar between LF and EL groups (P = 0.52). A significantly higher pooled rate of nerve palsies was found in the LF group compared to EL (9.9 vs 3.7 %, RR 2.76, P = 0.03). No significant difference was found in terms of operative time and intraoperative blood loss. CONCLUSIONS: From the available low-quality evidence, LF and EL approaches for CSM demonstrates similar clinical improvement and loss of lordosis. However, a higher complication rate was found in LF group, including significantly higher nerve palsy complications. This requires further validation and investigation in larger sample-size prospective and randomized studies.

Anterior Lumbar Interbody Fusion With and Without an "Access Surgeon": A Systematic Review and Meta-analysis.

STUDY DESIGN: A systematic review and meta-analysis. OBJECTIVE: The aim of this study was to investigate the outcomes of anterior lumber interbody fusion (ALIF) with and without an "access surgeon." SUMMARY OF BACKGROUND DATA: Anterior approaches for spine operations have become increasingly popular but may often involve unfamiliar anatomy and territory for spine surgeons, potentially placing the patient at risk to a greater proportion of approach-related complications. Thus, many spine surgeons require or prefer the assistance of an "access surgeon" to perform the exposure. However, there has been much debate about the necessity of an "access surgeon." METHODS: A systematic search of six databases from inception to April 2016 was performed by two independent reviewers. Meta-analysis was used to pool overall rates, and compare the outcomes of ALIF with an access surgeon and without. RESULTS: A total of 58 (8028 patients) studies were included in this meta-analysis. The overall intraoperative complications were similar with and without an "access surgeon." The overall pooled rate of arterial injuries [no access 0.44% vs. access 1.16%, odds ratio (OR) 2.67, P < 0.001], retrograde ejaculation (0.41% vs. 0.96%, OR 2.34, P = 0.005), and ileus (1.93% vs. 2.26%, OR 2.45, P < 0.001) was higher with an "access surgeon." However, the overall pooled rates of peritoneal injury (0.44% vs. 0.16%, OR 0.36, P = 0.034) and neurological injury (0.99% vs. 0.11%, OR 0.11, P < 0.001) were lower with an "access surgeon." Total postoperative complications (5.95% vs. 4.08%, OR 0.67, P < 0.001) were lower with an "access surgeon" along with prosthesis complications (1.59% vs. 0.89%, OR 0.56, P < 0.001) and reoperation rates (2.28% vs. 1.31%, OR 0.57, P < 0.001). CONCLUSION: Compared with no access surgeon, the use of an access surgeon was associated with similar intraoperative complication rates, higher arterial injuries, retrograde ejaculation, ileus, and lower prosthesis complications, reoperation rates, and postoperative complications. In cases wherein exposure may be difficult, support from an "access surgeon" should be available. LEVEL OF EVIDENCE: 1.

Treating multi-level cervical disc disease with hybrid surgery compared to anterior cervical discectomy and fusion: a systematic review and meta-analysis.

PURPOSE: The traditional surgical approach to treat multi-level cervical disc disease (mCDD) has been anterior cervical discectomy and fusion (ACDF). There has been recent development of other surgical approaches to further improve clinical outcomes. Collectively, when elements of these different approaches are combined in surgery, it is known as hybrid surgery (HS) which remains a novel treatment option. A systematic review and meta-analysis was conducted to compare the outcomes of HS versus ACDF for the treatment of mCDD. METHODS: Relevant articles were identified from six electronic databases from their inception to January 2016. RESULTS: From 8 relevant studies identified, 169 patients undergoing HS were compared with 193 ACDF procedures. Operative time was greater after HS by 42 min (p < 0.00001), with less intraoperative blood loss by 26 mL (p < 0.00001) and shorter return to work by 32 days (p < 0.00001). In terms of clinical outcomes, HS was associated with greater C2-C7 range of motion (ROM) preservation (p < 0.00001) and less functional impairment (p = 0.008) after surgery compared to ACDF. There was no significant difference between HS and ACDF with respect to postoperative pain (p = 0.12). The postoperative course following HS was not significantly different to ACDF in terms of length of stay (p = 0.24) and postoperative complication rates (p = 0.18). CONCLUSIONS: HS is a novel surgical approach to treat mCDD, associated with a greater operative time, less intraoperative blood loss and comparable if not superior clinical outcomes compared to ACDF. While it remains a viable consideration, there is a lack of robust clinical evidence in the literature. Future large prospective registries and randomised trials are warranted to validate the findings of this study.

Diagnostic criteria in amyotrophic lateral sclerosis: A multicenter prospective study.

OBJECTIVE: To assess the sensitivity and specificity of the Awaji and revised El Escorial diagnostic criteria (rEEC) in amyotrophic lateral sclerosis (ALS). METHODS: We conducted a large prospective multicenter study, recruiting 416 patients (253 male, 163 female) between January 1, 2012, and August 31, 2015, to compare the diagnostic accuracy of Awaji and rEEC in accordance with standards of reporting of diagnostic accuracy criteria. RESULTS: The sensitivity of the Awaji criteria (57%, 50.0%-63.3%) was higher when compared to rEEC (45%, 38.7%-51.7%, p < 0.001), translating to a 12% gain in sensitivity. The specificity of the both criteria were identical, 99.5%, indicating the number needed to test in order to diagnose one extra case of ALS was 1.8 (1.5-2) for Awaji criteria and 2.4 (2-2.6) for rEEC. The Awaji criteria exhibited a higher sensitivity across subgroups, including bulbar (p < 0.001) and limb-onset (p < 0.001) patients. The inclusion of the possible diagnostic category as a positive finding enhanced sensitivity of the Awaji criteria and rEEC, particularly in early stages of ALS, while maintaining specificity. CONCLUSION: The present study established a higher sensitivity of Awaji criteria when compared to rEEC, with diagnostic benefits evident in bulbar and limb-onset disease. Inclusion of possible as a positive finding enhanced sensitivity of both criteria, while maintaining specificity, and should be considered in clinical practice and future therapeutic trials. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that the Awaji criteria have a higher sensitivity and the same specificity as the rEEC in identifying patients with ALS.

Histological analysis of surgical samples and a proposed scoring system for infections in intervertebral discs.

Back pain remains one the most prevalent types of pain and disability worldwide. Infection is estimated to be the underlying cause in approximately 0.01% of patients. Despite recent evidence demonstrating prominent infection rates, a standardised algorithm for diagnosis of disc infection is lacking. Histopathological evaluation can aid in confirming inflammatory changes and also in identifying degenerative changes. Hence, standardising practice through a clear scoring system with regards to inflammation and degeneration may have some utility in the clinical setting. To our knowledge no such systems exist specifically for intervertebral disc infection. A literature review of current methods of scoring inflammation and degeneration in spine surgery and orthopaedic surgery was performed. Based on the current evidence, a scoring system for disc inflammatory and degenerative changes was proposed. We propose four domains for consideration: (1) granulation tissue, (2) dense fibrosis, (3) chronic inflammatory cells, and (4) neutrophil count. The non-standardised nature of diagnosing infections and degeneration in the spinal surgery literature means that this scoring system is currently of particular value. Based on a literature review, our proposed method for diagnosis incorporates a combination of histopathological criteria expected to increase diagnostic sensitivity in the setting of disc infection. Overall, scoring can be applied to surgically obtained material and integrated directly into routine pathological practice.

Bilateral versus unilateral instrumentation in spinal surgery: Systematic review and trial sequential analysis of prospective studies.

Lumbar fusion surgical intervention is often followed by bilateral pedicle screw fixation. There has been increasing support for unilateral pedicle screw fixation in an attempt to reduce complications and costs. The following study assesses the efficacy and complications of bilateral versus unilateral pedicle screw fixation in open and minimally invasive lumbar interbody fusion techniques. A systematic review with meta-analysis and trial sequential analysis was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and recommendations. In comparison with existing meta-analyses, trial sequential analysis was implemented to reduce the potential for type I error. Of the 1310 citations screened, four observational studies and 13 randomised controlled trials were used comprising 574 bilateral cases and 549 unilateral cases. Statistical analysis showed no difference in fusion rates, total complications, dural tear rates, Visual Analogue Scale (VAS) score for back pain, VAS for leg pain, Oswestry Disability Index scores, and length of stay between bilateral and unilateral instrumentation. Unilateral instrumentation was significantly shorter in duration (P<0.00001) and led to significantly lower blood volume loss (P=0.0002). These results were the same for both open and minimally invasive surgical approaches. Unilateral pedicle screw fixation appears to have similar post-operative outcomes as bilateral fixation and improved efficacy in regards to procedure duration and blood volume loss.

Rates of local procedural-related structural injury following clipping or coiling of anterior communicating artery aneurysms.

BACKGROUND: Surgical clipping and endovascular coiling yield similar functional outcomes for the treatment of saccular aneurysms of the anterior communicating (ACOM) artery. However, surgical treatment may be associated with greater rates of cognitive impairment due to injury of adjacent structures. We aimed to quantify the rates of injury (infarction/hemorrhage) for both clipping and coiling of ACOM aneurysms. METHODS: This was a retrospective dual-center radiological investigation of a consecutive series of patients with ruptured and unruptured ACOM aneurysms treated between January 2011 and October 2014. Post-treatment CT or MRI was assessed for new ischemic or hemorrhagic injury. Injury relating to the primary hemorrhage or vasospasm was differentiated. Univariate analysis using χ(2) tests and multivariate analysis using binary logistic regression was used. RESULTS: 66 patients treated with clipping were compared with 93 patients treated with coiling. 32/66 (48.5%) patients in the clipping group suffered treatment-related injury (31 ischemic, 1 hemorrhagic) compared with 4/93 (4.4%) patients in the coiling group (3 ischemic, 1 hemorrhagic) (p<0.0001). For patients with subarachnoid hemorrhage, the multivariate OR for infarction for clipping over coiling was 24.42 (95% CI 5.84 to 102.14), p<0.0001. The most common site of infarction was the basal forebrain (28/66 patients, 42.4%), with bilateral infarction in 4. There was injury of the septal/subcallosal region in 12/66 patients (18%). CONCLUSIONS: Clipping of ACOM aneurysms is associated with significantly higher rates of structural injury than coiling, and this may be a reason for superior cognitive outcomes in patients treated with coiling in previously published studies.

DISC (Degenerate-disc Infection Study With Contaminant Control): Pilot Study of Australian Cohort of Patients Without the Contaminant Control.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To evaluate if degenerative disc-related back or neck pain and/or radicular symptoms are caused by infection with low virulent bacterial organisms. SUMMARY OF BACKGROUND DATA: The potential relationship between disc infection and disc degeneration-related symptoms remains controversial, with contradictory evidence available in the literature. Several studies have demonstrated the presence of infected extruded nucleus tissue from first-time disc herniation, implicating the role of disc microbial infection in disc degeneration. The current study is a pilot study evaluating if high infection rates are prevalent in the Australian degenerate disc cohort. METHODS: Institutional ethics approval was obtained (HREC 13/218). The pilot project was a single spine center prospective cohort of patients undergoing spine surgery for degenerate disc disease. In each case, disc material was obtained and prolonged aerobic and anaerobic cultures performed as per methods used by Stirling et al. RESULTS: To date, a total of 168 patients have been enrolled, with male: female = 1:1. Surgical caseload includes 17.9% anterior cervical fusion, 35.0% anterior lumbar fusion, 40.7% lumbar discectomy, and 5.7% posterior lumbar fusions; 34.1% patients presented with neck pain, 31.6% with arm pain, 59.3% with leg pain, and 64.2% with back pain, and 20.2% of the patients received transforaminal or epidural or facet joint injections prior to surgery. In this pilot study, 19.6% were culture positive, with P. acnes predominant in 50%. Disc-only cultures were positive in 27.8% of lumbar cases and 18.5% of cervical cases, with predominant organisms being P. acnes. CONCLUSION: Similar to the infection rates from previous studies, this Australian cohort had 19.6% infection rates when disc-only cultures are performed. P. acnes is the predominant organism followed by Streptococcus sp. It is imperative to perform contaminant controls as such high infection with skin bugs is a significant finding. LEVEL OF EVIDENCE: 4.

Lateral lumbar interbody fusion for sagittal balance correction and spinal deformity.

We conducted a systematic review to assess the safety and clinical and radiological outcomes of the recently introduced, direct or extreme lateral lumbar interbody fusion (XLIF) approach for degenerative spinal deformity disorders. Open fusion and instrumentation has traditionally been the mainstay treatment. However, in recent years, there has been an increasing emphasis on minimally invasive fusion and instrumentation techniques, with the aim of minimizing surgical trauma and blood loss and reducing hospitalization. From six electronic databases, 21 eligible studies were included for review. The pooled weighted average mean of preoperative visual analogue scale (VAS) pain scores was 6.8, compared to a postoperative VAS score of 2.9 (p<0.0001). The weighted average preoperative and postoperative coronal segmental Cobb angles were 3.6 and 1.1°, respectively. The weighted average preoperative and postoperative coronal regional Cobb angles were 19.1 and 10.0°, respectively. Regional lumbar lordosis also significantly improved from 35.8 to 43.3°. Sagittal alignment was comparable pre- and postoperatively (34 mm versus 35.1mm). The weighted average operative duration was 125.6 minutes, whilst the mean estimated blood loss was 155 mL. The weighted average hospitalization length was 3.6 days. Whilst the available data is limited, minimally invasive XLIF procedures appear to be a promising alternative for the treatment of scoliosis, with improved functional VAS and Oswestry disability index outcomes and restored coronal deformity. Future comparative studies are warranted to assess the long term benefits and risks of XLIF compared to anterior and posterior procedures.