Comparison of hidden blood loss and clinical efficacy of percutaneous endoscopic transforaminal lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion.

PURPOSE: Hidden blood loss (HBL) is a growing area of interest for spinal surgeons. Simultaneously, spine surgeons' pursuit of minimally invasive spine surgery has never ceased, as evidenced by the increasing number of articles comparing percutaneous endoscopic transforaminal lumbar interbody fusion (Endo-TLIF) and minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF). However, there has been no comparison of HBL between Endo-TLIF and Mis-TLIF. This study aimed to compare HBL, visible blood loss (VBL), and total blood loss (TBL) following Endo-TLIF and Mis-TLIF and evaluate the clinical significance of these procedures. METHODS: Between October 2017 and October 2019, 370 patients underwent lumbar interbody fusion at our institution and were followed up for at least 24 months. Our study included 41 Endo-TLIF and 43 Mis-TLIF cases. We recorded each patient's age, height, weight, and haematocrit and calculated the TBL, which was used to indirectly obtain the HBL. Additionally, we compared the clinical outcomes of these two groups, including visual analogue scores for the lumbar spine and leg (VAS-Back; VAS-Leg), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) scores, disease type, operative segment, and intervertebral fusion and complication rates. RESULTS: Endo-TLIF had significantly lower HBL, VBL, and TBL values than Mis-TLIF (P < 0.05 for all). Although Endo-TLIF contained significantly less HBL than Mis-TLIF, the HBL to TBL ratio was statistically greater in Endo-TLIF (91%) than in Mis-TLIF (87%). Concerning clinical outcomes, VAS-Back, VAS-Leg, ODI, JOA, and Endo-TLIF demonstrated greater improvement rates than Mis-TLIF one week post-operatively. However, at the final follow-up, VAS-Back, VAS-Leg, ODI, and JOA scores all demonstrated a trend toward sustained improvement, with no statistically significant between-procedure difference. There were no statistically significant between-procedure differences in disease type, surgical segment, and complication or fusion rates. CONCLUSION: Endo-TLIF significantly reduced HBL, VBL, and TBL compared to Mis-TLIF and improved short-term clinical outcomes; however, long-term clinical outcomes and fusion rates remained comparable between the two groups, as did the incidence of peri-operative complications.

Percutaneous endoscopic-assisted direct repair of pars defect without general anesthesia could be a satisfying treatment alternative for young patient with symptomatic lumbar spondylolysis: a technique note with case series.

BACKGROUND: Multiple surgical procedures are applied in young patients with symptomatic lumbar spondylolysis when conservative treatments fail. Although the optimal surgical procedure option is controversial, the treatment paradigm has shifted from open surgery to minimally invasive spine surgery. To date, a limited number of studies on the feasibility of percutaneous endoscopic-assisted direct repair of pars defect have been carried out. Herein, for the first time, we retrospectively explore the outcomes of pars defect via percutaneous endoscopy. METHODS: We retrospectively examined young patients with spondylolysis treated using the percutaneous endoscopic-assisted direct repair of pars defect supplemented with autograft as well as percutaneous pedicle screw fixation between September 2014 and December 2018. Six patients with a mean age of 18.8 years were enrolled in the study. We used preoperatively computed tomographic (CT) scans to evaluate the size of pars defect, and graded disc degeneration using Pfirrmann's classification through magnetic resonance images (MRI). We assessed the clinical outcomes using the Oswestry Disability Index (ODI), 36-Item Short-Form Health Survey (SF-36) as well as Visual Analogue Scale for back pain (VAS-B). RESULTS: Our findings revealed that pain intensity and function outcomes, including VAS-B, ODI, and SF-36 (PCS and MCS) scores, were markedly improved after surgery and at the final follow-up visit. The change in the gap distance of the pars defect was remarkably significant after surgery and during the follow-up period. Only one of the 12 pars repaired was reported as a non-union at the final follow-up visit. Moreover, no surgery-related complications were reported in any of the cases. CONCLUSION: Percutaneous endoscopic-assisted direct repair of pars defect without general anesthesia, a minimally invasive treatment option, supplemented with autograft and percutaneous pedicle screw fixation, could be a satisfying treatment alternative for young patients with symptomatic lumbar spondylolysis.

miR-33a Mediates the Anti-Tumor Effect of Lovastatin in Osteosarcoma by Targeting CYR61.

BACKGROUND/AIMS: Preventing cell metastasis is an effective therapeutic strategy to treat osteosarcoma and improve prognosis. Statins have been found to have anticancer effects in addition to their cholesterol-lowering action. As a new target of statins, cysteine-rich 61 (CYR61) was recently identified to promote cell migration and metastasis in osteosarcoma. However, the underlying mechanisms mediating the regulation of CYR61 expression by statins remain unknown. METHODS: Human osteosarcoma cell lines MG63 and SaOS2 were used to clarify the effect of lovastatin on CYR61 expression. Real-time PCR was performed to detect mRNA or microRNA (miRNA) levels and western blot was performed to detect protein levels. Cell invasive ability was determined using Transwell assays. Lentivirus encoding CYR61 cDNA or sterol regulatory element-binding protein 2 (SREBP-2) shRNA was used to upregulate CYR61 expression or downregulate SREBP-2 expression. Binding of the CYR61 3' untranslated region (UTR) and miR-33a was analyzed by luciferase reporter assay. RESULTS: We found that lovastatin treatment decreased CYR61 expression, inhibited cell invasion and altered epithelial-to-mesenchymal-transition (EMT)-related protein expression, while CYR61 overexpression abolished the effect of lovastatin. Moreover, lovastatin increased the expression of SREBP-2 and miR-33a, which were then downregulated by SREBP-2 silencing. Bioinformatics analysis indicated that the CYR61 3'UTR harbored a potential miR-33a binding site and luciferase reporter assay demonstrated that CYR61 was a target of miR-33a in osteosarcoma cells. Furthermore, miR-33a could inhibit cell invasion and alter EMT-related protein expression. SREBP-2 silencing or miR-33a inhibitor upregulated CYR61 expression and reversed the effects of lovastatin on cell invasion and EMT-related proteins. CONCLUSION: Our findings suggest lovastatin suppresses osteosarcoma cell invasion through the SREBP-2/miR-33a/CYR61 pathway.

Coexistence of intervertebral disc herniation with intradural schwannoma in a lumbar segment: a case report.

BACKGROUND: Lumbar intervertebral disc herniation and spinal tumor are major pathologies that may cause back pain and radiculopathy. Neurological symptoms resulting from disc herniation and intradural spinal tumor together, however, are very rare. CASE PRESENTATION: We report a case of lumbar disc herniation which coexists with intradural schwannoma at the same spinal level in a 67-year-old man. The patient presented with persistent low back pain, sciatica, and weakness of the lower limbs. Contrast lumbar spine magnetic resonance (MR) imaging clearly delineated an intradural lesion and an extradural herniated disc at L3/4 level. Using a single posterior approach, both pathologies were addressed. Pathological studies confirmed the intradural lesion was schwannoma. CONCLUSION: The case report highlights a rare concomitance of two symptomatic pathologies in a lumbar spine, which deserves clinical attention. Complete history, careful physical examination, and investigative measures, such as contrast MR imaging, are helpful to establish throughout diagnoses.

MicroRNA-191 promotes osteosarcoma cells proliferation by targeting checkpoint kinase 2.

MicroRNAs (miRNAs) are small noncoding RNAs of 19-25 nt that can regulate gene expression at a posttranscriptional level. Increasing evidence indicates that miRNAs participate in almost every step of cellular processes and are often aberrantly expressed in human cancer. The aim of this study was to investigate the functional significance of miR-191 and to identify its possible target genes in osteosarcoma cells. Here, we found that the expression level of miR-191 was increased in osteosarcoma tissues in comparison with the adjacent normal tissues. The enforced expression of miR-191 was able to promote cell proliferation in Saos-2 and MG62 cells, while miR-191 antisense oligonucleotides blocked cell proliferation. At the molecular level, our results further revealed that expression of tumor suppressor gene, checkpoint kinase 2, was negatively regulated by miR-191. Therefore, we consider that miR-191 act as an onco-MicroRNA for osteosarcoma and it would offer a new way in molecular targeting cancer treatment.

Association between duration of playing video games and bone mineral density in Chinese adolescents.

The aim of the study was to investigate the association between duration of playing video games and bone mineral density (BMD) in Chinese adolescents. Three hundred eighty-four Chinese adolescents aged 14-18 yr (148 males and 236 females) were analyzed. Anthropometric measurements were obtained using standard procedures. Total body and regional BMD were measured using dual-energy X-ray absorptiometry. Duration of playing video games, defined as hours per day, was measured by a self-report questionnaire. We examined the association between duration of playing video games and BMD using multiple linear regression analysis. After adjustment for age, sex, pubertal stage, parental education, body mass index, adolescents with longer video game duration were more likely to have lower legs, trunk, pelvic, spine, and total BMD (p < 0.05). We concluded that duration of video game was negatively associated with BMD in Chinese adolescents. These findings provide support for reducing duration of playing video games as a possible means to increase BMD in adolescents. Future research is needed to elucidate the underlined mechanisms linking playing video games and osteoporosis.

Associations of fat mass and fat distribution with bone mineral density in Chinese obese population.

The purpose of the study was to investigate the associations of fat mass (FM) and fat distribution with bone mineral density (BMD) in Chinese obese population. Three hundred and forty-seven Chinese obese females and 339 males aged 20-39 years were analyzed. Lean mass (LM), FM, percent body fat (%BF), android FM, gynoid FM, and total and regional BMD were measured using dual-energy X-ray absorptiometry. Fat distribution was assessed by android-to-gynoid FM ratio (AOI). As a result, increased central body fat had an inverse association with total and leg BMD in females but not in males. Increased FM and %BF were positively associated with arm, trunk, and pelvic BMD in Chinese obese females. Increased FM was positively associated with total, rib, and trunk BMD in Chinese obese males. The results remained almost unchanged after adjusting for LM, and LM was significantly positively associated with spine BMD in female group. FM was positively associated with trunk BMD in male group after adjusting for LM. AOI was inversely associated with total and leg BMD, and %BF was positively associated with arm, trunk, and pelvic BMD when replacing FM with %BF in female group. The results remained almost unchanged after adjusting for LM. There is no significant association in male group when replacing FM with %BF. In conclusion, our findings demonstrate that there are different associations of FM and fat distribution with BMD, and AOI has a negative association with BMD.

Effect of Tranexamic Acid on Hidden Blood Loss in Percutaneous Endoscopic Transforaminal Lumbar Interbody Fusion: A Retrospective Study.

Purpose: Percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) has become one of the most popular minimally invasive surgeries today. However, the issue of hidden blood loss (HBL) in this surgery has received little attention. This study aims to examine the HBL in PE-TLIF surgery and the effect of tranexamic acid (TXA) on blood loss. Methods: In our research, We conducted a retrospective analysis of 300 patients who underwent PE-TLIF from September 2019 to August 2023. They were divided into 2 groups based on whether they received intravenous TXA injection before surgery. The variables compared included: demographic data, pre-and postoperative hemoglobin (HB), hematocrit (HCT), platelets (PLT), red blood cells (RBC), total blood loss (TBL), visible blood loss (VBL), HBL, operation time, postoperative hospital stay, inflammatory markers, coagulation parameters, and adverse events. Results: Regarding demographic characteristics, besides the operation time, no significant differences were observed between the two groups. Compared with the control group, the TXA group showed a significant reduction trend in TBL, HBL, and VBL (P < 0.05). On the first day after surgery, there were significant differences in prothrombin (PT), activated partial thromboplastin time (APTT), and D-dimer (D-D) levels between the two groups. Similarly, HCT also found similar results on the third day after surgery. No adverse events occurred in either group. Conclusion: Research has found that there is a significant amount of HBL in patients undergoing PE-TLIF. Intravenous injection of TXA can safely and effectively reduce perioperative HBL and VBL. Additionally, compared to the control group, the TXA group shows a significant reduction in operation time.

Determining the learning curve for percutaneous endoscopic lumbar interbody fusion for lumbar degenerative diseases.

PURPOSE: Percutaneous endoscopic lumbar interbody fusion (PELIF) is one of the least invasive procedures for lumbar degenerative disorders (LDD). There is limited knowledge of the learning curve for PELIF. METHODS: A total of 93 consecutive patients who underwent PELIF performed by a single spine surgeon for LDD failed with conservative treatment were retrospectively reviewed. The case series was split into three groups based on timing: A (earliest third of patients); B (middle third of patients); and C (latest third of patients). The following were also recorded: operating time, X-ray exposure time, complications, radiologic fusion rates, pre- and postoperative patient-reported outcome measures (PROMs) scores (visual analogue scale (VAS) for back pain, VAS for leg pain, Japanese Orthopaedic Association, Oswestry Disability Index and MacNab criteria), length of hospital stay, and need for revision surgeries. A learning curve was then developed by a logarithmic curve-fit regression analysis. RESULTS: The operative time gradually decreased over time, and an asymptote was reached after about 25 cases. Compared with group B or C, group A had significantly longer operative time, significantly longer length of hospital stay, needed significantly more x-ray exposure time. Though not significantly different, there are fewer complications and revision surgeries over time. There is no significant difference over time in PROMs scores except for the VAS back scores. CONCLUSIONS: PELIF is an alternative for minimal invasive surgery for LDD, PELIF presents a learning curve to the practicing spine surgeon with regard to operative time, x-ray exposure time, length of hospital stay, clinical PROMs and radiographic outcomes and complications. The presented PELIF learning curve provided valuable insight to surgeons interested in performing this surgery.

Cross-sectional analysis of the correlation between serum uric acid and trabecular bone score: NHANES 2005-2008.

Serum uric acid (SUA) has been discovered to be associated with bone mineral density (BMD), but its relationship with trabecular bone score (TBS) remains unclear. Thus, the aim of our study was to investigate the association between SUA levels and TBS. Our study included 5895 individuals over 20 years old (3061 men and 2834 women) from NHANES 2005-2008. To analyze the association between SUA and TBS, multivariate linear regression models with covariate adjustments were applied. Furthermore, population description, stratified analysis, single factor analysis, smooth curve fitting, interaction analysis, and threshold effect and saturation effect analysis were also conducted. After adjusting for covariates, SUA showed a strong negative relationship with total TBS (ß = 0.319; 95% CI 0.145-0.494; P < 0.001). The relationship between SUA levels and total TBS was found to be nonlinear, with inflection points at 4.8 mg/dL for the overall population, 4.2 mg/dL for women, and 5.7 mg/dL for non-Hispanic whites, indicating a saturation effect. Additionally, no interactions were found in any of the subgroups. Our study found a negative association between SUA and total TBS in adults. Maintaining SUA at a saturated level can benefit in preventing osteoporosis and fractures.

Frequency and Type of Ponticulus Posticus and Lateralis in a Chinese Population: A CT-Based Analysis of 4047 Cases.

AIM: To investigate the prevalence and type of ponticulus posticus (PP) and ponticulus lateralis (PL) in the Chinese population by analyzing computed tomography (CT) scans, and to uncover the pathogenesis of PP and PL. MATERIAL AND METHODS: A total of 4,047 cases were included in this study. We evaluated cervical spine CT scans with three dimensional reconstructions and collected age, gender, and presence of PP and PL in each case. If either or both were present, location and type were recorded. RESULTS: The overall prevalence of PP was 8.01%. The age of patients with PP was significantly higher than those without. Men had a higher prevalence of PP than women. The presence of PP was more common on the left side than the right. According to our previous classification, the most common type of a PP was AC (32.41%), followed by CC (20.06%) and CA (16.98%). The overall prevalence of PL was 4.67%, with no differences between age groups, genders or by location. The most common type of PL was AC (43.92%), followed by CA (35.98%) and CC (20.11%). The prevalence of PP and PL occurring in the same patient was 1.26%. CONCLUSION: Based on cervical spine CT scans of 4,047 Chinese patients, we found that the prevalence of PP and PL were 8.01% and 4.67%, respectively. PP was more common in older patients, which strongly suggests that PP may be a congenital osseous anomaly of the atlas that mineralizes during aging.

Publication Trends and Hot Spots in Subacromial Impingement Syndrome Research: A Bibliometric Analysis of the Web of Science Core Collection.

Background: In recent years, the research on subacromial impingement syndrome (SIS) has gradually increased. Although the research directions are diverse, the overall research status and trend are not clear. Objective: The aim of our study was to use bibliometric analysis to identify the trends in SIS-related research and to analyze the most highly cited scientific publications on SIS. Methods: All data were retrieved from the Web of Science Core Collection database, and the year of publications, countries, journals, institutions and total number of citations were extracted and analyzed. The results related to countries, institutions and keywords were then analyzed using VOSviewer software and bibliometrics online analysis platform. And, we also identified the 100 most cited articles on SIS. Results: A total of 548 articles related to AIS were identified. The frequency of publication on SIS has increased substantially over time. Among all countries, Turkey has contributed the most publications on SIS (n=118). The institution with the most articles was Istanbul University (n=17). Journal of Shoulder and Elbow Surgery topped the list of journals and has published 19 SIS-related publications. The hotspot of research changed from the former arthroscopic surgery to physical therapy and rehabilitation. Conclusion: The scientific research on SIS has rapidly expanded in recent years. This study represents the first bibliometric analysis of SIS, gives us a systematic and comprehensive summary into the development of SIS.

A Worldwide Bibliometric Analysis of Published Literature on Osteoporosis Vertebral Compression Fracture.

Background: With the aging population growth in the world, the prevalence of osteoporotic vertebral compression fracture (OVCF) is rapidly increasing and receiving widespread attention. Although there are numerous articles on the topic, the research status and hotspot analysis are unclear. Objective: The goal of this study is to identify trends in the OVCF field and to analyze the most highly cited original articles published in the Web of Science Index on OVCF using bibliometric analysis. Methods: All OVCF data were obtained from the Web of Science Core Collection, and the number of citations, institutions, journals, countries, and years of publication in this field were visually analyzed using VOSviewer, the bibliometrics online analysis platform, and Excel software. Simultaneously, the top 100 most cited articles were extracted and analyzed. Results: A total of 756 publications were related to OVCF were included from 1900 to 2022. In recent years, the number of articles on OVCF significantly increased. They are mainly from 41 countries/regions and 202 journals, led by China and the United States. Among all countries, China had the most significant contribution on OVCF (n = 363), and it also was cited most often (n = 3337). The institution with the most articles was Soochow University (n = 40). Osteoporosis International was the journal with most studies and has published 50 on this field. The journal of Spine was cited most often (n = 1968). The most productive periods were from 2016 to 2020, which received 294 articles and 4868 citations. After the analysis, the "vertebroplasty" and "kyphoplasty" of OVCF have been the most common research hotspots. Conclusion: This study represents an updated bibliometric analysis of OVCF. The aim is to identify current research hotspots and future trends to guide clinicians and researchers in this field.

Identification and comparison of novel circular RNAs with associated co-expression and competing endogenous RNA networks in postmenopausal osteoporosis.

BACKGROUND: Circular RNAs (circRNAs) are emerging as crucial regulators in various human diseases. So far, the expression profile and regulatory mechanism of circRNAs in postmenopausal osteoporosis (PMOP) are less studied and should be deciphered urgently. Herein, we aimed to reveal key circRNAs affecting PMOP and clarify their compounding regulatory actions. METHODS: To reveal key circRNAs affecting PMOP and clarify their compounding regulatory actions, whole transcriptome sequencing and bioinformatics analysis were performed to identify differentially expressed circRNAs (DECs). The expression pattern and regulatory networks of DECs in peripheral blood mononuclear cells (PBMCs) were unearthed. RESULTS: A total of 373 DECs comprising 123 intronic, 100 antisense, 70 exonic, 55 intergenic, and 25 sense-overlapping circRNAs were identified. Among these, 73 circRNAs were upregulated and 300 were downregulated. These DECs exerted pivotal functions in the pathogenesis of PMOP as demonstrated by Gene Ontology (GO) annotation and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The circRNA-miRNA-mRNA co-expression network comprising 28 DECs, 145 miRNAs, and 175 differentially expressed mRNAs predicted the possible mechanism of the pathogenesis and progression of PMOP. CONCLUSION: The results of the present study provided a further comprehension of circRNA-associated competing endogenous RNA regulatory mechanism in PMOP. The steadily expressed and disease-specific DECs may serve as promising diagnostic and prognostic biomarkers for PMOP.

miRNA-296-5p functions as a potential tumor suppressor in human osteosarcoma by targeting SND1.

BACKGROUND: The pathogenesis of osteosarcoma (OS) is still unclear, and it is still necessary to find new targets and drugs for anti-OS. This study aimed to investigate the role and mechanism of the anti-OS effects of miR-296-5p. METHODS: We measured the expression of miR-296-5p in human OS cell lines and tissues. The effect of miR-296-5p and its target gene staphylococcal nuclease and tudor domain containing 1 on proliferation, migration, and invasion of human OS lines was examined. The Student's t test was used for statistical analysis. RESULTS: We found that microRNA (miR)-296-5p was significantly downregulated in OS cell lines and tissues (control vs. OS, 1.802 ±â€Š0.313 vs. 0.618 ±â€Š0.235, t = 6.402, P < 0.01). Overexpression of miR-296-5p suppressed proliferation, migration, and invasion of OA cells. SND1 was identified as a target of miR-296-5p by bioinformatic analysis and dual-luciferase reporter assay. Overexpression of SND1 abrogated the effects induced by miR-296-5p upregulation (miRNA-296-5p vs. miRNA-296-5p + SND1, 0.294 ±â€Š0.159 vs. 2.300 ±â€Š0.277, t = 12.68, P = 0.003). CONCLUSION: Our study indicates that miR-296-5p may function as a tumor suppressor by targeting SND1 in OS.

Bibliometric and Visualized Analysis of Scientific Publications on Ossification of the Posterior Longitudinal Ligament Based on Web of Science.

BACKGROUND: In recent years, there has been increasing study of ossification of the posterior longitudinal ligament (OPLL), leading to many articles on this topic. We aimed to identify trends in OPLL-related research and to analyze the most highly cited scientific articles on OPLL. METHODS: We searched the Web of Science Core Collection database for all articles on OPLL. The years of publication, countries, journals, institutions, and total citations were extracted and analyzed. Results related to countries, institutions, and keywords were subjected to co-occurrence analysis using VOSviewer software. The top 100 most-cited articles on OPLL were analyzed. RESULTS: A total of 876 articles related to OPLL were identified. The frequency of publication on OPLL has increased substantially over time. Among all countries, Japan has contributed the most articles on OPLL (n = 349). The most productive institution has been Hirosaki University (n = 57). Spine topped the list of journals and has published 120 OPLL-related articles, which received 4221 total citations. The surgical treatment of OPLL has been the most common research focus in the OPLL literature. CONCLUSIONS: The scientific literature on OPLL has rapidly expanded in recent years. This study represents the first bibliometric analysis of scientific articles on OPLL and can serve as a useful guide to clinicians and researchers in the field.

The 100 Most-Cited Publications in Endoscopic Spine Surgery Research.

STUDY DESIGN: A bibliometric review of the literature. OBJECTIVE: Our objective was to identify and analyze the 100 most-cited publications in the field of endoscopic spine surgery (ESS). METHODS: In order to determine the top cited 100 articles, a 3-step approach was employed. First, the 100 most-cited ESS studies were identified using the key phrase "endoscopic spine surgery." Then, 8 keywords were identified from the 100 studies of step 1 were used to conduct a second round searching in all databases of the Web of Science. Finally, when the results of the first and second steps were overlapped, duplicated studies were removed. The 100 top-cited articles were used for further analysis. RESULTS: The citation number of the top 100 most-cited articles ranged from 44 to 236 with a mean value of 84.4. The most productive periods were from 2001 to 2010. The majority of publications came from Spine and Neurosurgery, where Spine holds the largest number of 35 articles, followed by Neurosurgery with 13 articles. Overall, 10 countries contributed to the 100 articles, with the most productive country being the United States, followed by Germany and Korea. CONCLUSION: This bibliometric study is meant to produce a list of intellectual milestones in the field of ESS. This article's identification of the most influential articles in the field of ESS gives us a unique and comprehensive insight into the development of ESS in the past several decades.

Percutaneous Transforaminal Endoscopic Lumbar Interbody Fusion for Degenerative Lumbar Diseases: A Consecutive Case Series with Mean 2-Year Follow-Up.

BACKGROUND: Conventional open surgical procedures may cause massive dissections of the spine, higher perioperative complications, prolonged hospitalization, protracted rehabilitation programs and recovery. Percutaneous endoscopic lumbar interbody fusion (PELIF) is an evolving treatment option. OBJECTIVES: To present the detailed procedure and preliminary clinical and radiologic results of PELIF for degenerative lumbar diseases. STUDY DESIGN: A retrospective cohort study. SETTING: A university affiliated tertiary hospital. METHODS: The medical records of patients with degenerative lumbar diseases who underwent PELIF between January 2016 and December 2017 were retrospectively reviewed. Surgical level, surgical time, blood loss, hospital length of stay, and perioperative complications were discussed. Patients were also evaluated for pain by the Visual Analog Scale (VAS), and functional assessment by the Oswestry Disability Index (ODI) and the 36-Item Short Form Health Survey (SF-36), including Physical Component Summary (PCS) and Mental Component Summary (MCS) preoperatively, postoperatively, and during the follow-up period. RESULTS: Thirty-nine consecutive patients (25 men and 14 women) with a mean age of 59.0 years (range, 39-77 years) were enrolled. The average surgical time was 213.8 ± 31.7 minutes (range, 185-324 minutes). Mean estimated blood loss was 25.0 ± 12.6 mL (range, 15-50 mL). At the latest follow-up visit, the VAS scores for back pain, leg pain, ODI, and SF-36 (MCS/PCS) scores improved 89.5%, 95.0%, 71.2%, and 37.5%/58%, respectively. Reoperations were performed in one patient for residual disc mass and one for misplacement of pedicle screw. Fusion was achieved in all patients. LIMITATIONS: The presented results are preliminary and should be interpreted taking the limitations into account, including nonrandomized design, relatively small sample size, and less intensive follow-up period. CONCLUSIONS: The presented PELIF technique seems to be a promising surgical alternative for the treatment of patients with specific degenerative lumbar diseases. Randomized studies with larger sample size and long-term follow-up duration are needed to validate the superiorities of this versatile surgery. KEY WORDS: Endoscopic, minimally invasive spine surgery, lumbar interbody fusion, disc herniation, spondylolisthesis.

Top 100 Cited Articles on Spinal Disc Arthroplasty Research.

STUDY DESIGN: A bibliometric review of current literature. OBJECTIVE: The purpose of this study was to identify and analyze the 100 most cited articles in spinal disc arthroplasty (SDA) research. SUMMARY OF BACKGROUND DATA: In the last several decades, SDA has been widely performed all over the world, with increasing popularity of cervical disc arthroplasty (CDA). While there is a large number of articles on this topic, to our knowledge, there is no bibliometric analysis yet. METHODS: All databases from the Web of Science were searched in a three-step approach. The information of the 100 most cited studies was collected, including title, first and last author, year of publication, journal, total citations, geographic origin, subspecialty, and types of artificial intervertebral disc for further analysis. RESULTS: The 100 most-cited articles were published from 1966 to 2015 in 9 different journals and were cited from 66 to 346 times. A total of 11 countries contributed to the 100 articles and the United States topped the list, with 54 articles, followed by Germany and France, with 10 and nine articles, respectively. There were more studies in CDA (n = 53) than lumbar disc arthroplasty (n = 35). Most of the studies reported clinical and radiographic outcomes (n = 33). The most productive periods were from 2006 to 2010. The majority of publications were in Spine, which published 43 articles. In total, 12 authors published more than two articles on the list. CONCLUSION: Of the top 100 most cited articles on SDA, cervical papers outnumbered lumbar articles and the United States had 55 articles, with no other countries having more than 10. Our paper can help readers determine which of the thousands of articles on this topic are the most impactful and important ones to be familiar with. LEVEL OF EVIDENCE: 3.

Percutaneous transforaminal endoscopic decompression for the treatment of intraspinal tophaceous gout: A case report.

RATIONALE: Intraspinal tophaceous gout is relatively rare condition presenting with major clinical manifestations, such as spinal cord or nerve roots compressions (radiculopathy). It is usually difficult to differentiate intraspinal tophaceous gout, lumbar disc herniation, stenosis of spinal canal, ossification of ligamentum flavum, and other degenerative spinal disorders from each other. PATIENT CONCERNS: A 64-year-old man was admitted with a history of progressive low back pain for 11 months. He also presented with radiculopathy and numbness of his left lower extremity. DIAGNOSES: Preoperative computed tomography (CT) and magnetic resonance imaging (MRI) showed L4/5 disc herniation and lateral recess stenosis on the left side. During the operation of percutaneous transforaminal endoscopic decompression, intraspinal chalky white material was seen. Post-operative pathologic results confirmed the diagnosis of gouty tophi. INTERVENTIONS: Percutaneous transforaminal endoscopic decompression was performed as treatment. Intraspinal chalky white material was seen. We removed most of the chalky white material and extruded nucleus. OUTCOMES: His symptom subsided rapidly and no deterioration was noted 1 year post-operatively. LESSONS: Although intraspinal tophaceous gout is not commonly seen, clinicians should take it into consideration as a possible differential diagnosis when the patient exhibits axial pain or neurological deficits with risk factors of gout. We identified and treated this case with percutaneous transforaminal endoscopic decompression for the first time and got an excellent outcome. Percutaneous transforaminal endoscopic surgery proved to be an effective and minimally invasive alternative for identifying and treating intraspinal tophaceous gout.