Daniel B. Scherman

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.

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 χ2 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.

Anterior Lumbar Interbody Fusion (ALIF) 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

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

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.

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.

Clinical presentation and surgical outcomes of an intramedullary C2 spinal cord cavernoma: a case report and review of the relevant literature

BACKGROUND The spinal cord intramedullary cavernoma (SCIC) is a rare form of hemangioma that typically behaves as a space-occupying lesion resulting in neurological symptoms, including bladder and bowel dysfunction. To date, there have been few reports characterizing the clinical presentations and surgical outcomes of cavernomas at the C2 spinal level or the potential for resolution of bladder and bowel symptoms postoperatively. This case details the clinical course of a patient with a C2 cavernoma with an atypical neurological presentation and rapid improvement in both bladder and bowel function postoperatively. This case reviews the relevant literature and describes the patients clinical presentation, radiological and pathological findings and post-surgical progress. METHODS A 56-year-old male presented with sensory changes in his right hand, which rapidly progressed over ensuing weeks to bilateral sensory changes in the upper and lower limbs, gait imbalance, urinary and faecal incontinence and loss of temperature perception. He subsequently developed significant weakness in the upper limbs. A MRI identified a hematoma in the cervical cord at the C2 level. Given his rapid neurological decline and the social and clinical implications of his bladder and bowel instability, a surgical approach to therapy was adopted. RESULTS Postoperatively, there was steady improvement in motor and sensory function and a complete return of bladder and bowel function. CONCLUSIONS Intramedullary spinal cord cavernomas, although rare, can cause significant neurological deficits and morbidity. Surgical excision can provide significant benefits, including restoration of bladder and bowel function.

Adjacent segment degeneration and disease following cervical arthroplasty: a systematic review and meta-analysis

Anterior cervical discectomy and fusion (ACDF) has been the gold standard for the relief of symptoms associated with cervical degenerative disc disease. However, consequent to the fusion resulting in cervical immobilization, many complications, including adjacent segment degeneration and disease, have been identified (1-3). Unlike ACDF, cervical arthroplasty preserves motion at both the index and adjacent disc levels and as such, potentially minimizes adjacent segment degeneration and disease.