Endovascular thrombectomy for tandem acute ischemic stroke associated with cervical artery dissection: a systematic review and meta-analysis.

PURPOSE: Strokes associated with cervical artery dissection have been managed primarily with antithrombotics with poor outcomes. The additive role of endovascular thrombectomy remains unclear. The objective was to perform systematic review and meta-analysis to compare endovascular thrombectomy and medical therapy for acute ischemic stroke associated with cervical artery dissection. METHODS: Studies from six electronic databases included outcomes of patient cohorts with acute ischemic stroke secondary to cervical artery dissection who underwent treatment with endovascular thrombectomy. A meta-analysis of proportions was conducted with a random effects model. Modified Rankin score at 90 days (mRS 0-2) was the primary outcome. Other outcomes included proportion of patients with thrombolysis in cerebral infarction (TICI) 2b-3 flow, 90-day mortality rate, and 90-day symptomatic intracerebral hemorrhage (sICH) rate. RESULTS: Six studies were included, comprising 193 cases that underwent thrombectomy compared with 59 cases that were managed medically. Successful recanalization with a pooled proportion of thrombolysis in cerebral infarction (TICI) 2b-3 flow in the thrombectomy group was 74%. Favorable outcome (mRS 0-2) was superior in the pooled thrombectomy group (62.9%, 95% CI 55.8-69.5%) compared with medical management (41.5%, 95% CI 29.0-55.1%, P = 0.006). The pooled rate of 90-day mortality was similar for endovascular vs medical (8.6% vs 6.3%). The pooled rate of symptomatic intracranial haemorrhage (sICH) did not significantly differ (5.9% vs 4.2%, P = 0.60). CONCLUSIONS: Current data suggest that endovascular thrombectomy may be an option in patients with acute ischemic stroke due to cervical artery dissection. This requires further confirmation in higher quality prospective studies.

Complications of cervical total disc replacement and their associations with heterotopic ossification: a systematic review and meta-analysis.

PURPOSE: Although cervical total disc replacement (CTDR) is perceived as a safe procedure, no review to date has quantified the complication rates. Of note, heterotopic ossification (HO), one of the complications of CTDR, is hypothesised to cause adjacent segment degeneration (ASDegeneration). This association has not been proven in meta-analysis. Hence, this systematic review and meta-analysis aims to investigate the pooled prevalence of complications following CTDR among studies that concomitantly reported the rate of HO, and the associations between HO and other complications, including ASDegeneration. METHODS: Literatures search was conducted in Embase, MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials. Complications were stratified into ≥ 1 and < 2 years, ≥ 2 and < 5 years, and ≥ 5 years follow-up. Subgroup and meta-regression analyses were performed. RESULTS: Fifty-three studies were included, composed of 3223 patients in total. The pooled prevalence of post-operative complications following CTDR was low, ranging from 0.8% in vascular adverse events to 4.7% in dysphagia at short-term follow-up. The rate of ASDegeneration was significantly higher at long-term follow-up (pooled prevalence 36.0%, 95% confidence interval [CI] 22.8-49.1%) than that at mid-term follow-up (pooled prevalence 7.3%, 95% CI 2.8-11.8%). Multivariate meta-regression analysis demonstrated that ASDegeneration was independently and inversely correlated with age (p = 0.007) and positively correlated with HO (p = 0.010) at mid-term follow-up. At long-term follow-up, ASDegeneration was still positively correlated with HO (p = 0.011), but not age. Furthermore, dysphagia was inversely associated with HO (p = 0.016), after adjustment for age and length of follow-up. CONCLUSION: In conclusion, HO is associated with ASDegeneration and dysphagia.

Correction to: 3D-printed spine surgery implants: a systematic review of the efficacy and clinical safety profile of patient-specific and off-the-shelf devices.

Unfortunately, 3rd author's first name was incorrectly published in the original publication. The complete correct name is given below.

3D-printed spine surgery implants: a systematic review of the efficacy and clinical safety profile of patient-specific and off-the-shelf devices.

PURPOSE: Three-dimensional printing (3DP), or additive manufacturing, is an emergent fabrication technology for surgical devices. As a production method, 3DP enables physical realisation of surgical implants from geometrically complex digital-models in computer-aided design. Spine surgery has been an innovative adopter of 3DP technology for both patient-specific (PS) and market-available 'Off-The-Shelf' (OTS) implants. The present study assessed clinical evidence for efficacy and safety of both PS and OTS 3DP spinal implants through review of the published literature. The aim was to evaluate the clinical utility of 3DP devices for spinal surgery. METHODS: A systematic literature review of peer-reviewed papers featured on online medical databases evidencing the application of 3DP (PS and OTS) surgical spine implants was conducted in accordance with PRISMA guidelines. RESULTS: Twenty-two peer-reviewed articles and one book-chapter were eligible for systematic review. The published literature was limited to case reports and case series, with a predominant focus on PS designs fabricated from titanium alloys for surgical reconstruction in cases where neoplasia, infection, trauma or degenerative processes of the spine have precipitated significant anatomical complexity. CONCLUSION: PS and 3DP OTS surgical implants have demonstrated considerable utility for the surgical management of complex spine pathology. The reviewed literature indicated that 3DP spinal implants have also been used safely, with positive surgeon- and patient-reported outcomes. However, these conclusions are tentative as the follow-up periods are still relatively short and the number of high-powered studies was limited. Single case and small case series reporting would benefit greatly from more standardised reporting of clinical, radiographic and biomechanical outcomes. These slides can be retrieved under Electronic Supplementary Material.

Clinical outcomes of locking stand-alone cage versus anterior plate construct in two-level anterior cervical discectomy and fusion: a systematic review and meta-analysis.

BACKGROUND: Two-level cervical degenerative disc disease (cDDD) can be effectively treated by anterior cervical discectomy and fusion (ACDF) similarly to single-level cDDD. Traditionally an anterior plate construct (APC) approach has been utilized, but ACDF without plate with a locking stand-alone cage (LSC) approach has emerged as an alternative option. The aim of this study was to compare the clinical outcome of LSC and APC in contiguous two-level ACDF used to treat cDDD the current literature. METHODS: Searches of seven electronic databases from inception to March 2018 were conducted following preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Extracted data were analysed using meta-analysis of proportions. RESULTS: The nine observational studies that satisfied all criteria described a pooled cohort of 687 contiguous two-level cDDD cases managed by ACDF, with 302 (44%) and 385 (56%) managed by LSC and APC approaches, respectively. When compared with APC, LSC was associated with significantly increased subsidence likelihood (OR 2.75; p < 0.001), greater disc height (MD 0.60 mm; p = 0.04) and reduced cervical lordosis (MD - 2.52°; p = 0.04) at last follow-up. Operative outcomes, fusion rates, functional scores and postoperative dysphagia rates were comparable. CONCLUSION: Although significant radiological differences were most evident, the comparability between LSC and APC in contiguous two-level ACDF with respect to all other clinical outcomes does not implicate one approach as clearly superior to the other in two-level ACDF. Larger, randomized studies with longer follow-up are required to delineate outcomes further to validate the findings of this study. These slides can be retrieved under Electronic Supplementary Material.

Antifibrinolytic agents for paediatric scoliosis surgery: a systematic review and meta-analysis.

STUDY DESIGN: Systematic review and meta-analysis of randomised controlled trials. OBJECTIVE: The purpose of this study is to perform a systematic review and meta-analysis of antifibrinolytic agents for paediatric spine surgery. BACKGROUND: Bleeding is an important consideration in paediatric scoliosis surgery; blood loss leads directly to higher morbidity and mortality. Antifibrinolytics are an attractive non-invasive method of reducing bleeding as evidenced in arthroplasty, cardiac surgery and adult scoliosis surgery. METHODS: A thorough database search of Medline, PubMed, EMBASE and Cochrane was performed according to PRISMA guidelines, and a systematic review was performed. RESULTS: Five randomised controlled trials were identified in this meta-analysis, consisting of a total of 285 spine surgery patients with subgroups of tranexamic acid (n = 101), epsilon aminocaproic acid (n = 61) and control (n = 123). This meta-analysis found that antifibrinolytics lead to statistically significant reductions in peri-operative blood loss (MD - 379.16, 95% CI [- 579.76, - 178.57], p < 0.001), intra-operative blood loss (MD - 516.42, 95% CI [- 1055.58, 22.74], p < 0.001), reduced fresh frozen plasma requirements (MD - 307.77, 95% CI [- 369.66, - 245.88], p < 0.001) and reduced post-operative blood loss (MD - 185.95, 95% CI [- 336.04, - 35.87], p = 0.02). CONCLUSION: This meta-analysis concludes that antifibrinolytics lead to statistically significant reductions in peri-operative blood loss, intra-operative blood loss, reduced fresh frozen plasma requirements and reduced post-operative blood loss with TXA. These slides can be retrieved under Electronic Supplementary Material.

The role of wearables in spinal posture analysis: a systematic review.

BACKGROUND: Wearables consist of numerous technologies that are worn on the body and measure parameters such as step count, distance travelled, heart rate and sleep quantity. Recently, various wearable systems have been designed capable of detecting spinal posture and providing live biofeedback when poor posture is sustained. It is hypothesised that long-term use of these wearables may improve spinal posture. RESEARCH QUESTIONS: To (1) examine the capabilities of current devices assessing spine posture, (2) to identify studies implementing such devices in the clinical setting and (3) comment on the clinical practicality of integration of such devices into routine care where appropriate. METHODS: A comprehensive systematic review was conducted in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines (PRISMA) across the following databases: PubMed; MEDLINE; EMBASE; Cochrane; and Scopus. Articles related to wearables systems able to measure spinal posture were selected amongst all published studies dated from 1980 onwards. Extracted data was collected as per a predetermined checklist including device types, study objectives, findings and limitations. RESULTS: A total of 37 articles were extensively reviewed and analysed in the final review. The proposed wearables most commonly used Inertial Measurement Units (IMUs) as the underlying technology. Wearables measuring spinal posture have been proposed to be used in the following settings: post-operative rehabilitation; treatment of musculoskeletal disorders; diagnosis of pathological spinal posture; monitoring of progression of Parkinson's Disease; detection of falls; workplace occupational health and safety; comparison of interventions. CONCLUSIONS: This is the first and only study to specifically review wearable devices that monitor spinal posture. Our findings suggest that currently available devices are capable of assessing spinal posture with good accuracy in the clinical setting. However, further validation regarding the long-term use of these technologies and improvements regarding practicality is required for commercialisation.

The role of wearable devices and objective gait analysis for the assessment and monitoring of patients with lumbar spinal stenosis: systematic review.

BACKGROUND: The purpose of this systematic review was to evaluate the accuracy and reliability of wearable devices for objective gait measurement of Lumbar Spinal Stenosis (LSS) patients, with a focus on relevant gait metrics. METHODS: Systematic searches were conducted of five electronic databases to identify studies that assessed gait metrics by wearable or portable technology. Data was collected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement guidelines. RESULTS: Four articles were identified for inclusion in this review. The objectives, methodology and quality of the studies varied. No single gait metric was investigated in all four studies, making comparison difficult. The most relevant metrics reported included gait cycle, gait velocity, step length and cadence, which were reported in two studies. Two studies explored gait symmetry. Differences between LSS patients and normal healthy subjects are demonstrable using wearable technology. CONCLUSIONS: The measurements of gait cycle, cadence, step length, gait velocity, and number of steps with wearable devices can be used in the gait measurement of LSS patients for initial assessment, and objective outcomes following interventions. However, data and analysis are limited, and further studies are necessary to comment on reliability.

Relationship between sagittal balance and adjacent segment disease in surgical treatment of degenerative lumbar spine disease: meta-analysis and implications for choice of fusion technique.

STUDY DESIGN: Meta-analysis. OBJECTIVE: To conduct a meta-analysis investigating the relationship between spinopelvic alignment parameters and development of adjacent level disease (ALD) following lumbar fusion for degenerative disease. ALD is a degenerative pathology that develops at mobile segments above or below fused spinal segments. Patient outcomes are worse, and the likelihood of requiring revision surgery is higher in ALD compared to patients without ALD. Spinopelvic sagittal alignment has been found to have a significant effect on outcomes post-fusion; however, studies investigating the relationship between spinopelvic sagittal alignment parameters and ALD in degenerative lumbar disease are limited. METHODS: Six e-databases were searched. Predefined endpoints were extracted and meta-analyzed from the identified studies. RESULTS: There was a significantly larger pre-operative PT in the ALD cohort versus control (WMD 3.99, CI 1.97-6.00, p = 0.0001), a smaller pre-operative SS (WMD - 2.74; CI - 5.14 to 0.34, p = 0.03), and a smaller pre-operative LL (WMD - 4.76; CI - 7.66 to 1.86, p = 0.001). There was a significantly larger pre-operative PI-LL in the ALD cohort (WMD 8.74; CI 3.12-14.37, p = 0.002). There was a significantly larger postoperative PI in the ALD cohort (WMD 2.08; CI 0.26-3.90, p = 0.03) and a larger postoperative PT (WMD 5.23; CI 3.18-7.27, p < 0.00001). CONCLUSION: The sagittal parameters: PT, SS, PI-LL, and LL may predict development of ALD in patients' post-lumbar fusion for degenerative disease. Decision-making aimed at correcting these parameters may decrease risk of developing ALD in this cohort. These slides can be retrieved under Electronic Supplementary Material.

Annular closure device for disc herniation: meta-analysis of clinical outcome and complications.

BACKGROUND: Lumbar intervertebral disc herniation is a common cause of lower back and leg pain, with surgical intervention (e.g. discectomy to remove the herniated disc) recommended after an appropriate period of conservative management, however the existing or increased breach of the annulus fibrosus persists with the potential of reherniation. Several prosthesis and techniques to reduce re-herniation have been proposed including implantation of an annular closure device (ACD) - Barricaid™ and an annular tissue repair system (AR) - Anulex-Xclose™. The aim of this meta-analysis is to assist surgeons determine a potential approach to reduce incidences of recurrent lumbar disc herniation and assess the current devices regarding their outcomes and complications. METHODS: Four electronic full-text databases were systematically searched through September 2017. Data including outcomes of annular closure device/annular repair were extracted. All results were pooled utilising meta-analysis with weighted mean difference and odds ratio as summary statistics. RESULTS: Four studies met inclusion criteria. Three studies reported the use of Barricaid (ACD) while one study reported the use of Anulex (AR). A total of 24 symptomatic reherniation were reported among 811 discectomies with ACD/AR as compared to 51 out of 645 in the control group (OR: 0.34; 95% CI: 0.20,0.56; I2 = 0%; P < 0.0001). Durotomies were lower among the ACD/AR patients with only 3 reported cases compared to 7 in the control group (OR: 0.54; 95% CI: 0.13, 2.23; I2 = 11%; P = 0.39). Similar outcomes for post-operative Oswestry Disability Index and visual analogue scale were obtained when both groups were compared. CONCLUSION: Early results showed the use of Barricaid and Anulex devices are beneficial for short term outcomes demonstrating reduction in symptomatic disc reherniation with low post-operative complication rates. Long-term studies are required to further investigate the efficacy of such devices.

Prior Lumbar Spinal Fusion is Associated With an Increased Risk of Dislocation and Revision in Total Hip Arthroplasty: A Meta-Analysis.

BACKGROUND: The biomechanical relationship between the lumbar spine and the hip is well-documented. It follows that fusing the lumbar spine would have implications on the outcomes of total hip arthroplasty (THA). This study aimed to determine the effect of preexisting lumbar spinal fusion surgery on the outcomes of THA by synthesizing the available evidence via systematic review and meta-analysis. METHODS: A systematic review with meta-analysis was performed in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic searches were performed in 6 different databases for studies comparing outcomes in patients after THA with or without a history of lumbar fusion. Studies were required to report at least one outcome out of dislocation, revision due to hip instability or patient-reported outcomes. RESULTS: Patients with a history of lumbar spinal fusion are at a significantly increased risk of dislocation (relative risk 2.03, P < .00001) and revision (relative risk 3.36, P = .006) after THA. Patient-reported outcomes were also poorer in patients with prior lumbar fusion compared with those without, although meta-analysis could not be performed due to heterogeneity in the outcome measure used between studies. CONCLUSION: Previous lumbar spinal fusion increases risk of dislocation and revision, and may negatively impacts patient-reported outcomes after THA. Orthopaedic surgeons should pay particular attention to these patients and could use patient-specific planning, instrumentation, and targeted counselling to optimize clinical and subjective outcomes. Future studies could clarify the impact of prior fusion on patient-reported outcomes after THA.

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.

Radiological and clinical outcomes of novel Ti/PEEK combined spinal fusion cages: a systematic review and preclinical evaluation.

PURPOSE: The primary objective of this paper was to provide a systematic review of the available clinical studies of Ti/PEEK combined cages in spinal interbody fusion surgeries, focusing on their radiological and clinical outcomes. A secondary aim was to provide a review and evaluation of the in vitro and preclinical studies reported on Ti/PEEK-coated implants. METHODS: A systematic search of the literature was performed in March 2015 via three databases: Medline, Embase and Cochrane library. The following key search terms were combined with synonyms to identify relevant articles: "spinal fusion," "PEEK," "titanium" and "cage." RESULTS: The novelty of this intervention translates into a paucity of clinical trials, albeit the results of the seven clinical studies that met the criteria for inclusion are promising. All studies reported rate of fusion as a primary outcome. Two studies reported slightly improved fusion in the experimental Ti/PEEK combination cohort, one study identical fusion (91.7 %) and three studies excellent fusion (96, 100 and 94 %) in the Ti/PEEK cohort, although no differences reached statistical significance. CONCLUSIONS: Clinical studies at this early stage demonstrate that Ti/PEEK implants are safe and efficacious, exhibiting similar fusion rates and clinical outcomes compared to the current standard PEEK. There is clinical evidence substantiating the improved radiographic fusion of Ti/PEEK, albeit the differences were not significant. This field is promising, gaining substantial popularity, and further clinical trials are needed in the future to establish Ti/PEEK cages as a mainstay of clinical practice.

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.

The role of specialist units to provide focused care and complication avoidance following traumatic spinal cord injury: a systematic review.

OBJECTIVE: Current recommendations for traumatic spinal cord injury treatment recommend immediate transfer to a spinal injury unit (SIU) where available following patient stabilisation. Although transfer is dependent on a variety of factors, the largest review was unable to justify implementation of such units on the basis of insufficient and lack of quality data in favour of care at the SIU as opposed to non-SIU centres. Our study sought to investigate: are subspecialty spinal injury units (SIUs) able to provide superior care compared with traditional trauma/rehab units? Is the standard of care of acute spinal cord injured patients to be managed in SIU's? METHOD: A literature search was conducted across five major databases using the key terms: "spinal cord injury" AND "Spinal Injury Unit" OR "spinal rehabilitation" OR "spinal injury centre" OR "specialist care" OR "care requirements." RESULTS: After review of over 500 studies, only 9 met inclusion criteria, 3 of which were past reviews. There were no relevant RCT's obtained. Standardised roles of global SIU units are needed to deliver equitable and high quality care as current evidence demonstrates variable standards of care and service (mean LOS range: 16-174 days). There is low quality evidence supporting earlier admission into SIU units being associated with improved neurological outcome, complication rates and reduced LOS, despite variations in the definition of "early admission" across studies. CONCLUSIONS: Our review demonstrates a lack of standardisation within SIU on a global scale, with significantly different outcomes reported across published studies. New and higher quality evidence directly comparing SIU to non-SIU based care is required. Earlier transfer (<24 h) to SIU following initial injury and stabilisation is advised.

Cost-utility of minimally invasive versus open transforaminal lumbar interbody fusion: systematic review and economic evaluation.

PURPOSE: To assess the cost-utility and perioperative costs of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) versus open-TLIF for degenerative lumbar pathologies. METHODS: Relevant articles were identified from six electronic databases. Predefined end points were extracted and meta-analysis conducted from the identified studies. RESULTS: For each study, the direct hospital cost for MI-TLIF was found to be less than that of open-TLIF. When these outcomes were pooled, direct hospital costs were found to be significantly lower in the MI-TLIF group [weighted mean difference (WMD), -$2820; I (2) = 61 %; P < 0.00001]. MI-TLIF was also associated with shorter hospitalization (WMD, 0.99; 95 % CI -1.81, -0.17; I (2) = 96 %; P = 0.02), trend toward reduced complications (relative risk 0.53; 95 % CI 0.23, 1.06; I (2) = 0 %; P = 0.07), and reduced blood loss (WMD, -246.40 mL; I (2) = 98 %; P = 0.003), but was not associated with a significant difference in operation time (WMD, -67.05; 95 % CI -169.44, 35.35; I (2) = 100 %; P = 0.20). CONCLUSIONS: From the limited evidence, the available data suggest a trend of significantly reduced perioperative costs, length of stay, and blood loss for minimally invasive compared with open surgical approaches for TLIF. MI-TLIF may represent an opportunity for optimal utilization and allocation of health-care resources from both a hospital and societal perspective.

Minimally invasive versus open transforaminal lumbar interbody fusion for treatment of degenerative lumbar disease: systematic review and meta-analysis.

PURPOSE: While open TLIF (O-TLIF) remains the mainstay approach, minimally invasive TLIF (MI-TLIF) may offer potential advantages of reduced trauma to paraspinal muscles, minimized perioperative blood loss, quicker recovery and reduced risk of infection at surgical sites. This meta-analysis was conducted to provide an updated assessment of the relative benefits and risks of MI-TLIF versus O-TLIF. METHODS: Electronic searches were performed using six databases from their inception to December 2014. Relevant studies comparing MI-TLIF and O-TLIF were included. Data were extracted and analysed according to predefined clinical end points. RESULTS: There was no significant difference in operation time noted between MI-TLIF and O-TLIF cohorts. The median intraoperative blood loss for MI-TLIF was significantly lower than O-TLIF (median: 177 vs 461 mL; (weighted mean difference) WMD, -256.23; 95% CI -351.35, -161.1; P < 0.00001). Infection rates were significantly lower in the minimally invasive cohort (1.2 vs 4.6%; relative risk (RR), 0.27; 95%, 0.14, 0.53; I2) = 0%; P = 0.0001). VAS back pain scores were significantly lower in the MI-TLIF group compared to O-TLIF (WMD, -0.41; 95% CI -0.76, -0.06; I2 = 96%; P < 0.00001). Postoperative ODI scores were also significantly lower in the minimally invasive cohort (WMD, -2.21; 95% CI -4.26, -0.15; I2 = 93%; P = 0.04). CONCLUSIONS: In summary, the present systematic review and meta-analysis demonstrated that MI-TLIF appears to be a safe and efficacious approach compared to O-TLIF. MI-TLIF is associated with lower blood loss and infection rates in patients, albeit at the risk of higher radiation exposure for the surgical team. The long-term relative merits require further validation in prospective, randomized studies.

The design evolution of interbody cages in anterior cervical discectomy and fusion: a systematic review.

BACKGROUND: Anterior cervical discectomy with fusion is a common surgical procedure for patients experiencing pain and/or neurological deficits due to cervical spondylosis. Although iliac crest bone graft remains the gold standard today, the associated morbidity has inspired the search for alternatives, including allograft, synthetic and factor/cell-based grafts; and has further led to a focus on cage fusion technology. Compared to their graft counterparts, cage interbody implants have enhanced biomechanical properties, with designs constantly improving to maximise biocompatibility and osseointegration. We present a systematic review examining the historical progress of implant designs and performance, as well as an update on the currently available designs, and the potential future of cervical interbody implants. METHODS: We performed a systematic review using the keywords "cervical fusion implant design", with no limits on year of publication. Databases used were PubMed, Medline, Embase and Cochrane. In addition, the search was extended to the reference lists of selected articles. RESULTS: 180 articles were reviewed and 64 articles were eligible for inclusion. Exclusion criteria were based around study design, implant information and patient cohorts. The evolution of cage implant design has been shaped by improved understanding of ideal anatomy, progress in materials research and continuing experimentation of structural design. Originally, designs varied primarily in their choice of structure, however long-term studies have displayed the overall advantages of non-threaded, wedge shaped cages in complementing healthy anatomical profiles, and thus focus has shifted to refining material utilisation and streamlining anterior fixation. CONCLUSIONS: Evolution of design has been dramatic over the past decades; however an ideal cage design has yet to be realised. Current research is focusing on the promotion of osseointegration through bioactiviation of surface materials, as well as streamlining anterior fixation with the introduction of integrated screws and zero profile designs. Future designs will benefit from a combination of these advances in order to achieve ideal disc heights, cervical alignments and fusions.