Comparative study of percutaneous endoscopic lumbar decompression and traditional revision surgery in the treatment of symptomatic adjacent segment degeneration.

OBJECTIVE: The objective of this study is to evaluate and compare the surgical outcomes and complications of Percutaneous Endoscopic Lumbar Decompression (PELD) and traditional revision surgery in treating symptomatic Adjacent Segment Degeneration (ASD). This comparison aims to delineate the advantages and disadvantages of these methods, assisting spine surgeons in making informed surgical decisions. METHODS: 66 patients with symptomatic ASD who failed conservative treatment for more than 1 month and received repeated lumbar surgery were retrospectively collected in the study from January 2015 to November 2018, with the average age of 65.86 ± 11.04 years old. According to the type of surgery they received, all the patients were divided in 2 groups, including 32 patients replaced the prior rod in Group A and 34 patients received PELD at the adjacent level in Group B. Patients were followed up routinely and received clinical and radiological evaluation at 3, 6, 12 months and yearly postoperatively. Complications and hospital costs were recorded through chart reviews. RESULTS: The majority of patients experienced positive surgical outcomes. However, three cases encountered complications. Notably, Group B patients demonstrated superior pain relief and improved postoperative functional scores throughout the follow-up period, alongside reduced hospital costs (P < 0.05). Additionally, significant reductions in average operative time, blood loss, and hospital stay were observed in Group B (P < 0.05). Notwithstanding these benefits, three patients in Group B experienced disc re-herniation and underwent subsequent revision surgeries. CONCLUSIONS: While PELD offers several advantages over traditional revision surgery, such as reduced operative time, blood loss, and hospital stay, it also presents a higher likelihood of requiring subsequent revision surgeries. Future studies involving a larger cohort and extended follow-up periods are essential to fully assess the relative benefits and drawbacks of these surgical approaches for ASD.

A posterior-only approach for ankylosing spondylitis (AS) with thoracolumbar pseudoarthrosis: a clinical retrospective study.

BACKGROUND: Surgical treatment has been recommended by most surgeons to treat pseudarthrosis in ankylosing spondylitis (AS). However, there is still some debate on the necessity of anterior fusion. There is very limited literature on the treatment and surgical outcomes of thoracolumbar pseudarthrosis in AS patients treated through a posterior-only approach. METHODS: From January 1, 2012 to December 31, 2017, a total of 42 cases diagnosed with thoracolumbar pseudarthrosis in AS patients with moderate kyphosis were included in this study. All of the patients received posterior-only kyphosis correction, internal fixation and fusion without anterior fusion, and underwent at least 2 years of follow-up. Clinical and radiographic results and complications were assessed. RESULTS: All of the patients were followed up for an average of 35.3 months (range, 24-48 months), and they achieved successful bone graft fusion at the pseudarthrosis sites. Satisfactory radiographic changes were achieved in these patients. The Cobb angles of global kyphosis (GK) were corrected from 53.2 ± 5.4 degrees preoperatively to 33.2 ± 4.3 degrees postoperatively, and to 36.1 ± 5.3 degrees at the latest follow-up. The Cobb angles of local kyphosis (LK) were corrected from 43.3 ± 4.6 degrees preoperatively to 26.8 ± 3.3 degrees postoperatively, and to 28.2 ± 3.6 degrees at the latest follow-up. The mean sagittal vertical axis (SVA) were corrected from 7.6 ± 4.2 cm preoperatively to 4.3 ± 2.1 cm postoperatively, and to 4.8 ± 2.3 cm at the latest follow-up. No serious neurological complication or deep wound infection was found in these 42 patients. CONCLUSION: Posterior-only kyphosis correction and fixation without anterior fusion can achieve excellent bone fusion and satisfactory improvement in AS patients with thoracolumbar pseudarthrosis. This method may be a good choice for treating thoracolumbar pseudarthrosis in AS patients with moderate kyphosis.

Surgical treatment of atlantoaxial subluxation by intraoperative skull traction and C1-C2 fixation.

BACKGROUND: Atlantoaxial subluxation (AAS) is a not rare abnormality between the atlas (C1) and axis (C2). For AAS patients with persistent neck pain and neurologic symptoms, surgical intervention is a good choice. Nevertheless, there were still few reports about the use of intraoperative skull traction and different fixation methods in treatment of AAS. METHODS: From January 2012 to December 2018, a total of 86 cases were admitted to our hospital and diagnosed as AAS. All the patients received atlantoaxial reduction with the help of intraoperative skull traction and C1-C2 fixation. Clinical and radiological parameters were collected through chart review. RESULTS: There were 86 cases included in this study. The mean operative time was 153.9 ± 73.9 min, and the mean amount of intraoperative blood loss was 219.1 ± 195.6 ml. 81 patients underwent posterior reduction, internal fixation and fusion. 5 patients underwent anterior release, followed by posterior internal fixation and fusion. 82 patients got satisfactory postoperative outcomes while complications occurred in 4 patients. Significant neurologic improvement was observed in these patients. Bone fusion was achieved on the midline sagittal reconstructed CT images at the latest follow-up in all these patients except 1 case. All the patients were followed up for 34.84 ± 15.86 months at average (range 12-60 months). The mean ADI value was 7.55 ± 1.67 mm at average preoperatively, and improved to 4.03 ± 1.21 mm postoperatively, and to 4.21 ± 0.99 mm at the latest follow-up. The mean A-A angle was 15.48 ± 9.82 degrees at average preoperatively, and improved to 21.61 ± 10.43 degrees postoperatively, and to 19.73 ± 8.13 degrees at the latest follow-up. The mean A-A height was 35.61 ± 7.66 mm at average preoperatively, and improved to 40.08 ± 8.5 mm postoperatively, and to 38.83 ± 6.97 mm at the latest follow-up. There were complications in 4 patients, including pedicle misplacement, pedicle screw fracture, infection and one death. CONCLUSION: Intraoperative skull traction can effectively facilitate the surgical procedures for ASS caused by different etiologies. Further research will be needed to investigate the safety and effectiveness of this method in the future.

Metal-organic framework derived hollow nitrogen-doped carbon sphere with cobalt phosphide in carbon nanotube for efficient oxygen evolution.

The sluggish kinetics of the electrocatalytic oxygen evolution reaction (OER) pose a significant challenge in the field of overall water splitting. Transition metal phosphides have emerged as promising catalysts for OER by modulating the charge distribution of surrounding atoms. In this study, we employed self-sacrificing templates to fabricate hollow N-doped carbon spheres containing small-sized Co2P embedded within carbon nanotubes through high-temperature calcination and phosphorization, referred to as HNCS-CNT-CoP. The obtained HNCS-CNT-CoP electrocatalyst exhibited excellent OER performance in an alkaline electrolyte due to the optimization of OH* adsorption energy and the large specific surface area created by the hollow structure. It demonstrated a low overpotential of 302 mV at a current density of 10 mA cm-2 and a low Tafel slope of 68.5 mV dec-1, attributed to the electron transport facilitated by the in situ formed carbon nanotubes. Furthermore, theoretical calculations revealed a suitable reaction energy (1.17 eV) in the critical formation of Co2P-*OOH for HNCS-CNT-CoP, significantly lower than the the rate-determining step of HNCS-CNT-Co (10.08 eV). These findings highlight the significance of hollow structures and Co2P-doping in the design of highly active non-noble metal OER electrocatalysts, enabling the reduction of energetic reaction barriers for future applications.

Comparison of Percutaneous Endoscopic Transforaminal and Interlaminar Approaches in Treating Adjacent Segment Disease Following Lumbar Decompression Surgery: A Clinical Retrospective Study.

BACKGROUND: Adjacent segment disease (ASD) is a common complication following posterior disc decompression and fusion surgery. Percutaneous endoscopic lumbar decompression surgery (PELD) has been used to treat ASD through either a transforaminal or interlaminar approach. However, to our limited knowledge there are no reports comparing the 2 approaches for treating ASD. OBJECTIVE: To evaluate clinical outcomes of PELD in treating ASD and comparing the surgical results and complications between the 2 approaches. This may be helpful for spinal surgeons when decision-making ASD treatment. STUDY DESIGN: A clinical retrospective study. SETTING: This study was conducted at the Department of Orthopedics of the Affiliated Hospital of Qingdao University. METHODS: From January 2015 through December 2019, a total of 68 patients with ASD who underwent PELD after lumbar posterior decompression with fusion surgery were included in this study. The patients were divided into a percutaneous endoscopic transforaminal decompression (PETD) group and a percutaneous endoscopic interlaminar decompression (PEID) group according to the approach used. The demographic characteristics, radiographic and clinical outcomes, and complications were recorded in both groups through a chart review. RESULTS: Of the 68 patients, 40 underwent PEID and 28 patients underwent PETD. Compared with their preoperative Visual Analog Scale (VAS) pain score and Oswestry Disability Index (ODI) score, all patients had significant postoperative improvement at 3 months, 6 months, one year and at the latest follow-up. There were no significant statistical differences in the VAS and ODI scores between PETD and PEID groups with a P value > 0.05. There was a significant statistical difference in the average fluoroscopy times between the PETD and PEID groups with a P value = 0.000. Revision surgery occurred in 8 patients: 6 patients who underwent PETD and 2 patients who underwent PEID. The revision rate showed a significant statistical difference between the 2 approaches with a P value = 0.039. LIMITATIONS: Firstly, the number of patients included in this study was small. More patients are needed in a further study. Secondly, the follow-up time was limited in this study. There is still no conclusion about whether the primary decompression with instruments will increase the reoperation rate after a PELD, and a longer follow-up is needed in the future. Thirdly, this study was a clinical retrospective study. Randomized or controlled trials are needed in the future in order to achieve a higher level of evidence. Fourthly, there were debates about PELD approach choices for ASDs, which may affect the comparison results between PETD and PEID. In our study, the approaches were mainly determined by the level and types of disc herniation, and the surgeons' preference. More patients with an ASD with different levels and types of disc herniation and surgical approaches are needed in the future to eliminate these biases. CONCLUSION: Percutaneous endoscopic lumbar decompression surgery is a feasible option for ASD following lumbar decompression surgery with instruments. Compared with PETD, PEID seems to be a better approach to treat symptomatic ASDs.

Clinical and Radiological Risk Factors of Early Recurrent Lumbar Disc Herniation at Six Months or Less: A Clinical Retrospective Analysis in One Medical Center.

BACKGROUND: Recurrent LDH (rLDH) is one of the most common causes of unsatisfactory outcomes after discectomy, which usually needs secondary surgery and leads to physical and psychological suffering for patients and substantial costs for society. OBJECTIVES: This study was conducted to analyze the risk factors of early rLDH (<= 6 months) and to reduce the incidence of early rLDH. STUDY DESIGN: A clinical retrospective study. METHODS: A total of 1,228 patients received percutaneous endoscopic lumbar discectomy surgery from January 2013 through December 2016; there was a minimum 5-year follow-up. Seventy-seven of them (6.27%) developed recurrences and were included in this study. According to the differences in recurrent time, patients were divided into 2 groups (<= 6 months and > 6 months). Clinical and radiological parameters were retrospectively collected through chart review and preoperative imaging. All related risk factors were collected and analyzed relative to the time of recurrent herniation. RESULTS: Patients with rLDH at <= 6 months and > 6 months were 49 and 28, respectively. Recurrence most often occurred within 6 months postoperatively, which was 63.6% of the total patients with rLDH. Of those risk factors, Modic changes, disc height index (DHI), and facet orientation (FO) showed significant statistical differences P = 0.003, P = 0.036, and P = 0.007, respectively). A logistic regression analysis was performed and showed there was an independent significant relationship between Modic changes (P = 0.042) and FO (P = 0.005) and early rLDH. LIMITATIONS: First, this was a retrospective nonrandomized study, and the number of patients with rLDH included in this study was relatively small. Second, limited risk factors were assessed in this study, and some relevant risk factors that were identified as significant independent predictors in other studies were not included in this study, such as canal diameter, annular defect size, migrated disc, and foraminoplasty. Third, this study compared the clinical and radiological parameters of patients with rLDH at different times, and one case-control study is needed for further study, especially in terms of standardized sampling and data classification. CONCLUSION: This study demonstrated that the recurrence rate of LDH at 5-year follow-up was 6.27% and there was a significant statistical relationship between FO, DHI, and Modic changes and early rLDH. Surgeons should take FO angles, DHI, and Modic change into consideration before surgery to achieve a satisfactory postoperative outcome and a relatively lower early recurrence rate. More patients and further investigation should be taken to assess the risk factors for early rLDH.