Lumbar degenerative disease is a common problem in an aging society. Oblique lateral interbody fusion (OLIF) is a minimally invasive surgical (MIS) technique that utilizes a retroperitoneal antepsoas corridor to treat lumbar degenerative disease. OLIF has theoretical advantages over other lumbar fusion techniques, such as a lower risk of lumbar plexus injury than direct lateral interbody fusion (DLIF). Previous studies have reported favorable clinical and radiological outcomes of OLIF in various lumbar degenerative diseases. The use of OLIF is increasing, and evidence on OLIF is growing in the literature. The indications for OLIF are also expanding with the help of recent technical developments, including stereotactic navigation systems and robotics. In this review, we present current evidence on OLIF for the treatment of lumbar degenerative disease, focusing on the expansion of surgical indications and recent advancements in the OLIF procedure.

Spinal metastasis is a common issue causing significant pain and disability in cancer patients. A multidisciplinary approach consisting of chemotherapy, radiotherapy, and surgical treatment is used for treating patients with metastatic spinal tumors. Due to recent advancements in medical and radiation oncology, like tumor genetics and stereotactic radiotherapy, this treatment strategy would change inevitably. Therefore, the decision-making systems developed for assisting physicians and surgeons to choose the most appropriate treatment for each patient with spinal metastasis need to evolve. In this review, the recent developments, validations, and modifications of these systems, as well as suggestions for future systems have been discussed. Recently, separation surgery combined with stereotactic radiotherapy (hybrid therapy) has gained popularity. Additionally, the evidence for hybrid therapy presented in the literature has been reviewed.

This review comprehensively examines the evolution and current state of interbody cage technology for lumbar interbody fusion (LIF). This review highlights the biomechanical and clinical implications of the transition from traditional static cage designs to advanced expandable variants for spinal surgery. The review begins by exploring the early developments in cage materials, highlighting the roles of titanium and polyetheretherketone in the advancement of LIF techniques. This review also discusses the strengths and limitations of these materials, leading to innovations in surface modifications and the introduction of novel materials, such as tantalum, as alternative materials. Advancements in three-dimensional printing and surface modification technologies form a significant part of this review, emphasizing the role of these technologies in enhancing the biomechanical compatibility and osseointegration of interbody cages. In addition, this review explores the increase in biodegradable and composite materials such as polylactic acid and polycaprolactone, addressing their potential to mitigate long-term implant-related complications. A critical evaluation of static and expandable cages is presented, including their respective clinical and radiological outcomes. While static cages have been a mainstay of LIF, expandable cages are noted for their adaptability to the patient’s anatomy, reducing complications such as cage subsidence. However, this review highlights the ongoing debate and the lack of conclusive evidence regarding the superiority of either cage type in terms of clinical outcomes. Finally, this review proposes future directions for cage technology, focusing on the integration of bioactive substances and multifunctional coatings and the development of patient-specific implants. These advancements aim to further enhance the efficacy, safety, and personalized approach of spinal fusion surgeries. Moreover, this review offers a nuanced understanding of the evolving landscape of cage technology in LIF and provides insights into current practices and future possibilities in spinal surgery.

Objectives: Oblique lateral interbody fusion is considered a useful surgical option for various lumbar degenerative diseases with favorable clinical results and few complications. However, clinical outcomes following oblique lateral interbody fusion stratified according to the preoperative diagnosis have not been fully evaluated in a large cohort. The purpose of the present study was to evaluate the clinical outcomes following oblique lateral interbody fusion for lumbar degenerative disease and to identify differences in outcomes when stratified according to preoperative diagnosis.Methods: All patients receiving oblique lateral interbody fusion for lumbar degenerative diseases were included in the current study and were stratified into four diagnostic groups: (i) degenerative spondylolisthesis; (ii) spondylolytic spondylolisthesis; (iii) spinal stenosis without spondylolisthesis and instability; and (iv) deformity. Clinical outcomes were assessed using multiple patient‐reported questionnaires. Radiologic outcomes, including cage subsidence and completion of fusion, were also evaluated.Results: Overall, 169 patients with 262 operative levels were included in the study. All clinical scoring items showed significant improvement at 1 year postoperatively for all diagnostic groups. Net and percent improvement, and a proportion of patients reaching a threshold for substantial clinical benefit were not significantly different between the diagnostic groups in all scoring items, except for lower extremity radiating pain of the deformity group. Although the deformity group had the highest overall complication rate, neurologic complications were more frequent in the spondylolytic spondylolisthesis group. The rate of complete fusion and cage subsidence for individual levels at 1 year postoperatively was 62.7% and 32.6% respectively, with no significant difference between the diagnostic groups.Conclusions: The large single‐institution prospective cohort of the present study showed favorable clinical outcomes following oblique lateral interbody fusion for lumbar degenerative disease, even in spinal stenosis without spondylolisthesis and instability.

Spinal metastasis is the most common metastatic skeletal disease in cancer patients. Metastatic epidural spinal cord compression (MESCC), which occurs in 5–14% of cancer patients, is an oncological emergency because it may cause a permanent neurological deficit. Separation surgery followed by stereotactic ablative radiotherapy (SABR), so-called “hybrid therapy,” has shown effectiveness in local control of spinal metastasis and has become an integral treatment option for patients with MESCC. Therefore, we performed a meta-analysis and meta-regression analysis to clarify the local progression rate of hybrid therapy and the risk factors for local progression. We searched PubMed, EMBASE, Scopus, Cochrane Library, and Web of Science databases from inception to December 2021. Meta-analyses of proportions were used to analyze the data using a random-effects model to calculate the pooled 1-year local progression rate and confidence interval. Subgroup analyses were performed using meta-analyses of odds ratio (OR) for comparisons between groups. We also conducted a meta-regression analysis to identify the factors that caused heterogeneity. A total of 661 patients from 13 studies (10 retrospective and 3 prospective) were included in the final meta-analysis. The quality of the included studies assessed using the Newcastle − Ottawa scale ranged from poor to fair (range, 4–6). The pooled local progression rate was 10.2 % (95 % confidence interval [CI], 7.8–12.8 %; I² = 30 %) and 13.7 % (95 % CI, 9.3–18.8 %; I² = 55 %) at postoperative 1 and 2 years, respectively. The subgroup analysis indicated that patients with a history of prior radiotherapy (OR, 5.14; 95 % CI, 1.71–15.51) and lower radiation dose per fraction (OR, 4.57; 95 % CI, 1.88–11.13) showed significantly higher pooled 1-year local progression rates. In the moderator analysis, the 1-year local progression rate was significantly associated with the proportion of patients with a history of prior radiotherapy (p = 0.036) and those with colorectal cancer as primary origin (p < 0.001). The pooled 1-year local progression rate of hybrid therapy for MESCC was 10.2%. In subgroup and moderator analyses, a lower radiation dose per fraction, history of prior radiotherapy, and colorectal cancer showed a significant association with the 1-year local progression rate.