Degenerative disc and facet joint disease of the lumbar spine is common in the ageing population, and is one of the most frequent causes of disability. Lumbar spondylosis may result in mechanical back pain, radicular and claudicant symptoms, reduced mobility and poor quality of life. Surgical interbody fusion of degenerative levels is an effective treatment option to stabilize the painful motion segment, and may provide indirect decompression of the neural elements, restore lordosis and correct deformity. The surgical options for interbody fusion of the lumbar spine include: posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), minimally invasive transforaminal lumbar interbody fusion (MI-TLIF), oblique lumbar interbody fusion/anterior to psoas (OLIF/ATP), lateral lumbar interbody fusion (LLIF) and anterior lumbar interbody fusion (ALIF). The indications may include: discogenic/facetogenic low back pain, neurogenic claudication, radiculopathy due to foraminal stenosis, lumbar degenerative spinal deformity including symptomatic spondylolisthesis and degenerative scoliosis. In general, traditional posterior approaches are frequently used with acceptable fusion rates and low complication rates, however they are limited by thecal sac and nerve root retraction, along with iatrogenic injury to the paraspinal musculature and disruption of the posterior tension band. Minimally invasive (MIS) posterior approaches have evolved in an attempt to reduce approach related complications. Anterior approaches avoid the spinal canal, cauda equina and nerve roots, however have issues with approach related abdominal and vascular complications. In addition, lateral and OLIF techniques have potential risks to the lumbar plexus and psoas muscle. The present study aims firstly to comprehensively review the available literature and evidence for different lumbar interbody fusion (LIF) techniques. Secondly, we propose a set of recommendations and guidelines for the indications for interbody fusion options. Thirdly, this article provides a description of each approach, and illustrates the potential benefits and disadvantages of each technique with reference to indication and spine level performed.

Systematic review with meta-analysis. To assess the relative merits of minimally invasive unilateral laminectomy for bilateral decompression (ULBD) versus open laminectomy, a systematic review and meta-analysis of all available evidence was performed. Lumbar spinal stenosis is one of the most common pathologies in the increasingly elderly population that results in claudication, back and leg pain, and disability. The conventional approach for decompression is open laminectomy. In recent years, there has been a surge in microendoscopic procedures, which aim to minimize invasiveness. Despite the increasing use of these minimally invasive techniques, few studies have directly compared the safety, efficacy, and outcomes of these procedures with conventional laminectomy. There is a lack of robust clinical evidence, with most reports limited to single-center, inadequately powered, noncomparative studies. Relevant articles were identified from six electronic databases. Predefined endpoints were extracted and meta-analyzed from the identified studies. Satisfaction rates were significantly higher in the minimally invasive group (84% vs. 75.4%; P = 0.03), whereas back pain Visual Analog Scale scores were lower (P < 0.00001). Minimally invasive laminectomy operative duration was 11 minutes longer than the open approach (P = 0.001), however this may not have clinical significance. However, there was less blood loss (P < 0.00001) and shorter hospital stay (2.1 days; P < 0.0001). Dural injuries and cerebrospinal fluid leaks were comparable, but reoperation rates were lower in the minimally invasive cohort (1.6% vs. 5.8%; P = 0.02); however this was not significant when only randomized evidence was considered. The pooled evidence suggests ULBD may be associated with less blood loss and shorter stay, with similar complication profiles to the open approach. These findings warrant verification in large prospective registries and randomized trials. 1.

Three-dimensional printing (3DP), also known as “Additive Manufacturing”, is a rapidly growing industry, particularly in the area of spinal surgery. Given the complex anatomy of the spine and delicate nature of surrounding structures, 3DP has the potential to aid surgical planning and procedural accuracy. We perform a systematic review of current literature on the applications of 3DP in spinal surgery. Six electronic databases were searched for original published studies reporting cases or outcomes for 3DP surgical models, guides or implants for spinal surgery. The findings of these studies were synthesized and summarized. These searches returned a combined 2,411 articles. Of these, 54 were included in this review. 3DP is currently used for surgical planning, intra-operative surgical guides, customised prostheses as well as “Off-the-Shelf” implants. The technology has the potential for enhanced implant properties, as well as decreased surgical time and better patient outcomes. The majority of the data thus far is from low-quality studies with inherent biases linked with the excitement of a new field. As the body of literature continues to expand, larger scale studies to evaluate advantages and disadvantages, and longer-term follow up will enhance our knowledge of the effect 3DP has in spinal surgery. In addition, issues such as financial impact, time to design and print, materials selection and bio-printing will evolve as this rapidly expanding field matures.