Percutaneous kyphoplasty combined with zoledronic acid for the treatment of primary osteoporotic vertebral compression fracture: a prospective, multicenter study.

INTRODUCTION: To explore the therapeutic efficacy of percutaneous kyphoplasty (PKP) combined with zoledronic acid (ZOL) in postmenopausal women and adult men with osteoporotic vertebral compression fracture (OVCF). MATERIALS AND METHODS: A total of 238 patients with OVCF were randomly assigned to the control or ZOL group: 119 patients were treated with only PKP (control group), and 119 were treated with ZOL infusion after PKP (ZOL group). Clinical, radiological and laboratory indices were evaluated at follow-up. RESULTS: The visual analog scale (VAS) score and Oswestry Disability Index (ODI) were significantly higher in both groups post-treatment than at baseline (all p < 0.01). The bone mineral density (BMD) of the proximal femoral neck and height of the injured vertebra were significantly increased after treatment compared with before treatment, and the Cobb angle of the injured vertebra was significantly decreased in both groups (all p < 0.01). However, the bone metabolism indices (type I procollagen amino-terminal peptide (PINP), beta type I collagen carboxy-terminal peptide (ß-CTX), and osteocalcin in the N-terminal molecular fragment (NMID)) were significantly lower post-treatment than at baseline in only the ZOL group (all p < 0.01). The VAS score, ODI, BMD, PINP level, ß-CTX level, NMID level, vertebral height and Cobb angle of the injured vertebra were significantly higher in the ZOL group than in the control group (all p < 0.01). There were no significant differences in the postoperative bone cement leakage rate between the two groups. At follow-up, new OVCFs were experienced by 16 patients in the control group and 2 patients in the ZOL group (p < 0.01). CONCLUSION: The therapeutic efficacy of PKP combined with ZOL for primary OVCF is clinically beneficial and warrants further study.

A review of the hemivertebrae and hemivertebra resection.

Hemivertebra (HV) is a congenital spinal abnormality. Most hemivertebrae have normal growth plates so create a progressive deformity with growth leading to asymmetric loads on adjacent vertebrae which also show an asymmetric growth. We review the condition and its treatment.

A comparison of a new zero-profile, stand-alone Fidji cervical cage and anterior cervical plate for single and multilevel ACDF: a minimum 2-year follow-up study.

PURPOSE: To compare perioperative parameters, clinical outcomes, radiographic parameters, and complication rates of the new zero-profile, stand-alone Fidji cervical cage with those of the stand-alone cages with a titanium plate for anterior cervical discectomy and fusion (ACDF) for the surgical treatment of single- and multilevel cervical degenerative disc disease (DDD). METHODS: Between October 2009 and December 2013, 152 consecutive patients [86 males and 52 females; mean age 51.0 years (range 30-69 years)] with cervical DDD, who underwent surgery and were followed for more than 2 years, were enrolled in this study and divided into the cage group and plate group. The study compared perioperative parameters, surgery-related and implant-related complication rates, clinical outcomes, and radiologic parameters. RESULTS: The clinical and radiologic results in both groups were satisfactory after a minimum 2-year follow-up. No significant differences between the cage group and plate group in terms of improvement in the 36-Item Short Form Health Survey, visual analogue scale, Neck Disability Index, Japanese Orthopedic Association scores, disc height, mean fusion time, fusion rate, adjacent segment degeneration, and restoration of cervical lordosis, but the cage group was associated with a lower risk of postoperative dysphagia, shorter operation time, less blood loss, less cost of index surgery, and relatively greater simplicity than the plate group. CONCLUSIONS: The zero-profile, stand-alone Fidji cervical cage for ACDF is an effective, reliable, and safe alternate to the conventional method for the treatment of cervical DDD. However, there is no definitive evidence that Fidji cervical cage has better intermediate-term outcomes than the stand-alone cages with a titanium plate for ACDF.

A cost-utility analysis of Dynesys dynamic stabilization versus instrumented fusion for the treatment of degenerative lumbar spine diseases.

BACKGROUND: Symptomatic chronic low back and leg pain resulting from lumbar spine degenerative disorders is highly prevalent in China, and for some patients, surgery is the final option for improvement. Several techniques for spinal non-fusion have been introduced to reduce the side-effects of fusion methods and hasten postoperative recovery. In this study, the authors have evaluated the cost-effectiveness of Dynesys posterior dynamic stabilization system (DY) compared with lumbar fusion techniques in the treatment of single-level degenerative lumbar spinal conditions. METHODS: A total of 221 patients undergoing single-level elective primary surgery for degenerative lumbar pathology were included. 2-Year postoperative health outcomes of Visual Analogue Scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), 36-Item Short Form Health Survey (SF-36) and EuroQol-5 Dimensions (EQ-5D) questionnaires were recorded. 2-Year back-related medical resource use, missed work, and health-state values (Quality-adjusted life-year [QALY]) were assessed. Cost-effectiveness was determined by the incremental cost per QALY gained. RESULTS: At each follow-up point, both cohorts were associated with significant improvements in VAS scores, ODI, SF-36 scores and EQ-5D QALY scores, which persisted at the 2-year evaluation. The 2-year total mean cost per patient were significantly lower for Dynesys system ($20,150) compared to fusion techniques ($25,581, $27,862 and $27,314, respectively) (P < 0.001). Using EQ-5D, the mean cumulative 2-year QALYs gained were statistically equivalent between the four groups (0.28, 0.27, 0.30 and 0.30 units, respectively) (P = 0.74). Results indicate that patients implanted with the DY system derive lower total costs and more utility, on average, than those treated with fusion. CONCLUSIONS: The Dynesys dynamic stabilization system is cost effective compared to instrumented lumbar fusion for treatment of single-level degenerative lumbar disorders. It is not possible to state whether DY or lumbar fusion is more cost-effective after 2 years.

The E3 ligase RNF185 negatively regulates osteogenic differentiation by targeting Dvl2 for degradation.

Osteoblast plays a pivotal role in bone metabolism and bone remodeling by mediating bone formation and regulating the activity of osteoclast. Clarifying the regulators and regulation mechanisms of osteogenic differentiation of mesenchymal stem cells (MSCs) and pre-osteoblasts will provide tremendous promise for bone repair and bone regeneration. RNF185 was identified as a candidate of endogenous suppressors of osteogenic specification in human mesenchymal stem cells (hMSCs). Here we show that RNF185 down regulates osteogenic differentiation of mouse calvaria-derived MC3T3-E1 cells, confirmed by quantitative real-time-PCR (qRT-PCR) and alkaline phosphatase (ALP) activity. Further we confirm that RNF185 interacts with dishevelled2 (Dvl2), a key mediator of Wnt signaling pathway. Overexpression of RNF185 decreases the exogenous and endogenous level of Dvl2, promotes the ubiquitination and degradation of Dvl2 and inhibits Wnt signaling, which is evident from the down-regulation of ß-catenin mediated transcriptional activity. And Dvl2 reverses the effect of RNF185 on osteogenic differentiation of MC3T3-E1 cells. Taken together, our results indicate that RNF185 negatively regulates osteogenesis through the degradation of Dvl2 and down-regulation of canonical Wnt signaling pathway and suggest a possible therapeutic target in osteoporosis.

Neonatal bee venom exposure induces sensory modality-specific enhancement of nociceptive response in adult rats.

OBJECTIVE: Previous studies have shown that inflammatory pain at the neonatal stage can produce long-term structural and functional changes in nociceptive pathways, resulting in altered pain perception in adulthood. However, the exact pattern of altered nociceptive response and associated neurochemical changes in the spinal cord in this process is unclear. METHOD: In this study, we used an experimental paradigm in which each rat first received intraplantar bee venom (BV) or saline injection on postnatal day 1, 4, 7, 14, 21, or 28. This was followed 2 months later by a second intraplantar bee venom injection in the same rats to examine the difference in nociceptive responses. RESULTS: We found that neonatal inflammatory pain induced by the first BV injection significantly reduced baseline paw withdrawal mechanical threshold, but not baseline paw withdrawal thermal latency, when rats were examined 2 months from the first BV injection. Neonatal inflammatory pain also exacerbated mechanical, but not thermal, hyperalgesia in response to the second BV injection in these same rats. Rats exposed to neonatal inflammation also showed up-regulation of spinal NGF, TrkA receptor, BDNF, TrkB receptor, IL-1ß, and COX-2 expression following the second BV injection, especially with prior BV exposure on postnatal day 21 or 28. CONCLUSION: These results indicate that neonatal inflammation produces sensory modality-specific changes in nociceptive behavior and alters neurochemistry in the spinal cord of adult rats. These results also suggest that a prior history of inflammatory pain during the developmental period might have an impact on clinical pain in highly susceptible adult patients.

Biomechanical effects of different instrumented segments and trunk shifts on distal adjacent segments after congenital scoliosis posterior hemivertebrectomy: Preliminary results of a single case.

Objective: The present study aims to discuss the biomechanical effects of the sagittal vertical axis and different instrumented segments on distal adjacent segments after congenital scoliosis posterior hemivertebrectomy. Method: A case of congenital scoliosis caused by hemivertebra was selected for the reconstruction of the preoperative and postoperative 3D computed tomography data of the full spine. A finite element model of different fusion lengths and postoperative trunk shift (TS) values was established using the finite element method to compare the biomechanical effects of different models on the distal adjacent segment. Result: In the L1-L3 and T12-L1-L3-L4 fusion modes, the horizontal shift of the 1st vertebra below the lowest instrumented vertebra (LIV) increased with the trunk shift (TS) expansion after operation, and the imbalance between the left and right vertical stress of the 1st intervertebral disc below the LIV increased. With the decrease in fused segments in cases of TS = 10 mm and TS = 5 mm, the 1st vertebra below the LIV was subjected to a greater unbalanced force in the horizontal direction, and the 1st intervertebral disc below the LIV was subjected to a smaller imbalance between the left and right vertical stress after operation. Conclusion: When treating congenital scoliosis with hemivertebrectomy and pedicle screw fixation, fused segments can be properly extended and the postoperative TS shortened with a view of reducing the imbalance between the left and right stress of the 1st intervertebral disc below the LIV as well as the horizontal shift of the 1st vertebra below the LIV.

Two-Stage Deep Learning Model for Diagnosis of Lumbar Spondylolisthesis Based on Lateral X-Ray Images.

BACKGROUND: Diagnosing early lumbar spondylolisthesis is challenging for many doctors because of the lack of obvious symptoms. Using deep learning (DL) models to improve the accuracy of X-ray diagnoses can effectively reduce missed and misdiagnoses in clinical practice. This study aimed to use a two-stage deep learning model, the Res-SE-Net model with the YOLOv8 algorithm, to facilitate efficient and reliable diagnosis of early lumbar spondylolisthesis based on lateral X-ray image identification. METHODS: A total of 2424 lumbar lateral radiographs of patients treated in the Beijing Tongren Hospital between January 2021 and September 2023 were obtained. The data were labeled and mutually identified by 3 orthopedic surgeons after reshuffling in a random order and divided into a training set, validation set, and test set in a ratio of 7:2:1. We trained 2 models for automatic detection of spondylolisthesis. YOLOv8 model was used to detect the position of lumbar spondylolisthesis, and the Res-SE-Net classification method was designed to classify the clipped area and determine whether it was lumbar spondylolisthesis. The model performance was evaluated using a test set and an external dataset from Beijing Haidian Hospital. Finally, we compared model validation results with professional clinicians' evaluation. RESULTS: The model achieved promising results, with a high diagnostic accuracy of 92.3%, precision of 93.5%, and recall of 93.1% for spondylolisthesis detection on the test set, the area under the curve (AUC) value was 0.934. CONCLUSIONS: Our two-stage deep learning model provides doctors with a reference basis for the better diagnosis and treatment of early lumbar spondylolisthesis.

Anterior decompression with single segmental spinal interbody fusion for Denis type B thoracolumbar burst fracture: a midterm follow-up study.

PURPOSE: Our goal was to observe the midterm results of a case series of Denis type B thoracolumbar burst fracture treated with anterior decompression with single segmental spinal Interbody fusion. METHODS: Twenty patients with Denis type B thoracolumbar burst fractures underwent anterior decompression with single segmental spinal Interbody fusion. They underwent clinical and radiologic follow-up for at least three years after the surgery. RESULTS: The mean follow-up period lasted 57 months. To the last follow-up, there were no cases of internal fixation loosening, failure and other complications. Titanium mesh or interbody bone grafts were in good position. Spinal kyphosis was not observed. Interbody fusion was achieved for all cases. The average fusion time was 4.5 months. Based on visual analogue scale (VAS) pain scores, percentage of vertebral body height loss and Cobb angle, the difference was statistically significant between the preoperative period and postoperative one year or final follow-up (P < 0.05). Results at postoperative one year and final follow-up were better than the preoperative period. However, the difference was not significant between postoperative one year and final follow-up (P > 0.05). CONCLUSIONS: Good midterm results on clinical and radiologic evaluation of anterior decompression with single segmental spinal Interbody fusion for suitable patients with Denis type B thoracolumbar burst fracture can be achieved. The incident rate of relative complications is low.

Percutaneous Pedicle Screw Fixation with Percutaneous Endoscopic Transforaminal Lumbar Interbody Fusion in the Treatment of Degenerative Lumbar Spondylolisthesis with Instability.

OBJECTIVE: To evaluate the safety and efficacy of percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) in patients with L4-L5 degenerative lumbar spondylolisthesis (DLS) with instability. METHODS: The clinical data of 27 patients with L4-L5 DLS who underwent PE-TLIF from September 2019 to April 2022 were retrospectively reviewed. A minimum of 12 months of follow-up visits was provided to all patients. The demographics, perioperative, and clinical outcomes were reviewed based on the visual analog scale (VAS), Oswestry Disability Index (ODI), and modified MacNab criteria. Brantigan criteria estimated the result of interbody fusion at 12 months. RESULTS: The mean age was 70.70 ± 8.91 (55-83) years. The mean ± standard deviation values of the preoperative visual analog scale for back pain, leg pain, and Oswestry Disability Index were 7.37 ± 1.01, 7.26 ± 0.94, and 66.22 ± 7.49, respectively. The values improved to 1.66 ± 0.62, 1.74 ± 0.52, and 19.55 ± 5.56 at 12 months postoperatively (P ＜ 0.05). The modified MacNab criteria revealed that 88.89% (24/27) of patients achieved good-to-excellent outcomes. The interbody fusion rate was 100% at the final follow-up. CONCLUSIONS: In patients with L4-L5 DLS with instability, PE-TLIF under conscious sedation and local anesthesia could be an effective supplement for open decompression and fusion.

[Observation of early clinical efficacy of unilateral biportal endoscopy technique in the treatment of lumbar postoperative adjacent segmental diseases].

OBJECTIVE: To investigate early clinical efficacy of unilateral biportal endoscopy technique for the treatment of lumbar postoperative adjacent segmental diseases. METHODS: Fourteen patients with lumbar postoperative adjacent segmental diseases were treated with unilateral biportal endoscopy technique from June 2019 to June 2020. Among them, there were 9 males and 5 females, aged from 52 to 73 years old, and the interval between primary and revision operations ranged from 19 to 64 months. Adjacent segmental degeneration occurred after lumbar fusion in 10 patients and after lumbar nonfusion fixation in 4 patients. All the patients received unilateral biportal endoscopy assisted posterior unilateral lamina decompression or unilateral approach to the contralateral decompression. The operation time, postoperative hospital stay and complications were observed. The visual analogue scale (VAS) of low back pain and leg pain, Oswestry Disability Index (ODI), modified Japanese Orthopaedic Association (mJOA) score were recorded before operation and at 3 days, 3 months, and 6 months after operation. RESULTS: All procedures were successfully completed. Surgical duration ranged from 32 to 151 min. Postoperative CT showed adequate decompression and preservation of most joints. Out of bed walking 1 to 3 days after surgery, postoperative hospital stay was 1 to 8 days, and postoperative follow-up was 6 to 11 months. All 14 patients returned to normal life within 3 weeks after surgery, and VAS, ODI, and mJOA scores improved significantly at 3 days and 3, 6 months after surgery. One patient occurred cerebrospinal fluid leak after operation, received local compression suture, and the wound healed after conservative treatment. One patient occurred postoperative cauda equina neurologic deficit, which was gradually recovered about 1 month after rehabilitation therapy. One patients advented transient pain of lower limbs after surgery, and the symptoms were relieved after 7 days of treatment with hormones, dehydration drugs and symptomatic management. CONCLUSION: Unilateral biportal endoscopy technique has a good early clinical efficacy in the treatment of lumbar postoperative adjacent segmental diseases, which may provide a new minimally invasive, non-fixation option for the treatment of adjacent segment disease.

Os odontoideum associated with a retro-odontoid cyst treated with posterior C1-C3 fixation: A case report and literature review.

Background: Os odontoideum is a rare abnormality of the upper cervical spine, and os odontoideum associated with a retro-odontoid cyst has been described as a marker of local instability. Case description: This paper reports a case of a 52-year-old female patient who was diagnosed with os odontoideum associated with a retro-odontoid cyst. The patient underwent posterior C1-C3 fixation without surgical removal of the cyst. Magnetic resonance imaging (MRI) two days later revealed that the retro-odontoid cyst was still present and that there were no significant changes to it when compared with the preoperative MRI. Conclusion: Retro-odontoid cysts associated with unstable os odontoideum can lead to symptomatic spinal cord compression. Posterior C1-C3 fixation can restore atlantoaxial stability by allowing the gradual resorption of the cyst and ensuring spinal cord decompression. Fixation can also avoid the surgical risk associated with a high-riding vertebral artery.

An Analysis of the Risk Factors for Adding-on Phenomena After Posterior Hemivertebral Resection and Pedicle Screw Fixation for the Treatment of Congenital Scoliosis Caused by Hemivertebral Malformation.

Objective: To retrospectively analyze the risk factors for adding-on phenomena (AOP) after posterior hemivertebral resection (PHR) and pedicle screw fixation for the treatment of congenital scoliosis (CS) caused by hemivertebral (HV) malformation. Methods: Patients with CS who underwent surgery and were followed up for more than five years were included in this study. The d general data, such as gender, age, HV segment, Risser sign, and triangular cartilage, postoperative complications, and imaging data at different periods, including the standard anteroposterior and lateral x-rays of the total spine were collected. Results: In total, 58 patients were included in this study, of which 10 experienced AOP and 48 did not. The results of the single-factor analysis showed that there were statistically significant differences between the patients with AOP and those without in terms of the HV direction, lowest instrumented vertebra (LIV)-upper instrumented vertebra (UIV) (P < 0.05), and postoperative trunk shift (P < 0.05). The results of the logistic regression analysis showed that the HV direction and the postoperative trunk displacement distance were the main risk factors for postoperative AOP. The area under the receiver operating characteristic curve was 0.842 (P < 0.001). The best cut-off value of the adding-on index as an indicator of the occurrence of AOP after surgery was 0.67. When the adding-on index was >0.67, the incidence of postoperative AOP was 90.0%, and the non-occurrence rate was 22.9%. Conclusion: PHR and pedicle screw fixation is an effective way to treat HV malformation in CS. The HV direction, LIV-UIV, and postoperative TS are risk factors for AOP in patients with CS treated with PHR and pedicle screw fixation. The adding-on index has a high degree of accuracy for the prediction of the occurrence of AOP after PHR and pedicle screw fixation.

Clinical comparison of percutaneous transforaminal endoscopic discectomy and unilateral biportal endoscopic discectomy for single-level lumbar disc herniation.

Purpose: To compare the clinical outcomes of percutaneous transforaminal endoscopic discectomy (PTED) and unilateral biportal endoscopic discectomy (UBE) for the treatment of single-level lumbar disc herniation (LDH). Materials and methods: From January 2020 to November 2021, 62 patients with single-level LDH were retrospectively reviewed. All patients underwent spinal surgeries at the Affiliated Hospital of Chengde Medical University and Beijing Tongren Hospital, Capital Medical University. Among them, 30 patients were treated with UBE, and 32 were treated with PTED. The patients were followed up for at least one year. Patient demographics and perioperative outcomes were reviewed before and after surgery. The Oswestry Disability Index (ODI), visual analog scale (VAS) for back pain and leg pain, and modified MacNab criteria were used to evaluate the clinical outcomes. x-ray examinations were performed one year after surgery to assess the stability of the lumbar spine. Results: The mean ages in the UBE and PTED groups were 46.7 years and 48.0 years, respectively. Compared to the UBE group, the PTED group had better VAS scores for back pain at 1 and 7 days after surgery (3.06 ± 0.80 vs. 4.03 ± 0.81, P < 0.05; 2.81 ± 0.60 vs. 3.70 ± 0.79, P < 0.05). The UBE and PTED groups demonstrated significant improvements in the VAS score for leg pain and ODI score, and no significant differences were found between the groups at any time after the first month (P > 0.05). Although the good-to-excellent rate of the modified MacNab criteria in the UBE group was similar to that in the PTED group (86.7% vs. 87.5%, P > 0.05), PTED was advantageous in terms of the operation time, estimated blood loss, incision length, and length of postoperative hospital stay. Conclusions: Both UBE and PTED have favorable outcomes in patients with single-level LDH. However, PTED is superior to UBE in terms of short-term postoperative back pain relief and perioperative quality of life.

Reconstruction of the Anterior Cruciate Ligament Using Ruler-Assisted Positioning of the Femoral Tunnel Relative to the Posterior Apex of the Deep Cartilage: A Single-Center Case Series.

The techniques available to locate the femoral tunnel during anterior cruciate ligament (ACL) reconstruction have notable limitations. To evaluate whether the femoral tunnel center could be located intraoperatively with a ruler, using the posterior apex of the deep cartilage (ADC) as a landmark. This retrospective case series included consecutive patients with ACL rupture who underwent arthroscopic single-bundle ACL reconstruction at the Department of Orthopedics, Beijing Tongren Hospital between January 2014 and May 2018. During surgery, the ADC of the femoral lateral condyle was used as a landmark to locate the femoral tunnel center with a ruler. Three-dimensional computed tomography (CT) was performed within 3 days after surgery to measure the femoral tunnel position by the quadrant method. Arthroscopy was performed 1 year after surgery to evaluate the intra-articular conditions. Lysholm and International Knee Documentation Committee (IKDC) scores were determined before and 1 year after surgery. The final analysis included 82 knees of 82 patients (age = 31.7 ± 6.1 years; 70 males). The femoral tunnel center was 26 ± 1.5% in the deep-shallow (x-axis) direction and 31 ± 3.1% in the high-low (y-axis) direction, close to the "ideal" values of 27 and 34%. Lysholm score increased significantly from 38.5 (33.5-47) before surgery to 89 (86-92) at 1 year after surgery (p < 0.001). IKDC score increased significantly from 42.5 (37-47) before surgery to 87 (83.75-90) after surgery (p < 0.001). Using the ADC as a landmark, the femoral tunnel position can be accurately selected using a ruler.

Long-term clinical observation of patients with acute and chronic complete spinal cord injury after transplantation of NeuroRegen scaffold.

Spinal cord injury (SCI) often results in an inhibitory environment at the injury site. In our previous studies, transplantation of a scaffold combined with stem cells was proven to induce neural regeneration in animal models of complete SCI. Based on these preclinical studies, collagen scaffolds loaded with the patients' own bone marrow mononuclear cells or human umbilical cord mesenchymal stem cells were transplanted into SCI patients. Fifteen patients with acute complete SCI and 51 patients with chronic complete SCI were enrolled and followed up for 2 to 5 years. No serious adverse events related to functional scaffold transplantation were observed. Among the patients with acute SCI, five patients achieved expansion of their sensory positions and six patients recovered sensation in the bowel or bladder. Additionally, four patients regained voluntary walking ability accompanied by reconnection of neural signal transduction. Among patients with chronic SCI, 16 patients achieved expansion of their sensation level and 30 patients experienced enhanced reflexive defecation sensation or increased skin sweating below the injury site. Nearly half of the patients with chronic cervical SCI developed enhanced finger activity. These long-term follow-up results suggest that functional scaffold transplantation may represent a feasible treatment for patients with complete SCI.

Periprosthetic joint infection after total knee arthroplasty: a bibliometrics analysis.

BACKGROUND: Total knee arthroplasty (TKA) has brought hope to patients with malignant knee joint diseases. Infection is one of the serious complications after TKA, and the purpose of this study was to use bibliometrics to analyze the current research status of infection after this surgery, to unmask any deficiencies with current research, and to provide references for future researchers. METHODS: We used the Science Citation Index Expanded (SCI-E) database in the Web of Science Core Collection (WOSCC) as the data source, using the search terms "total knee arthroplasty" and "infection" respectively. The "And" operation was performed on the search results of the two subject terms, and the intersection of the two search results was taken as the final search result. CiteSpace software was used to analyze the results. RESULTS: The search results consisted of 5,600 documents, with a total citation frequency of 148,871. The average number of citations for each literature was 26.58, and the h-index was 142. The top five countries in the number of publications were the United States, China, Germany, the United Kingdom, and Spain, while the top five centrally ranked countries were the United States, the Netherlands, Germany, the United Kingdom, and France. The top five institutions with the number of publications were Thomas Jefferson Univ, Mayo Clin, Hosp Special Surg, Rush Univ, and Cleveland Clin, while the top institutions for centrality were Thomas Jefferson Univ, Tel Aviv Univ, Univ Melbourne, and Rush Univ. The top five authors of the number of published articles were Parvizi J, Mont MA, Valle CJD, Chen AF, and Hanssen AD, and the top three authors for centrality were Parvizi J, Mont MA, and Valle CJD. The main journals were J Bone Joint Surg Am, Clin Orthop Relat R, J Arthroplasty, J Bone Joint Surg Br, and Int Orthop, and the top five keywords used were total knee arthroplasty, total hip arthroplasty, replacement, infection, and arthroplasty. CONCLUSIONS: There is a lack of studies with high-level evidence. The focus of related research in recent years has not changed significantly. More randomized controlled studies are required to provide evidence-based medicine.

Comparison of Percutaneous Transforaminal Endoscopic Discectomy and Microendoscopic Discectomy for the Surgical Management of Symptomatic Lumbar Disc Herniation: A Multicenter Retrospective Cohort Study with a Minimum of 2 Years' Follow-Up.

BACKGROUND: Percutaneous transforaminal endoscopic discectomy (PTED) and microendoscopic discectomy (MED) are alternative minimally invasive procedures for the treatment of symptomatic lumbar disc herniation (LDH). However, insufficient literature exists to highlight the differences between the procedures. OBJECTIVES: This study intended to clarify whether PTED results in better clinical outcomes compared with MED in the surgical management of single-level LDH. STUDY DESIGN: A multicenter retrospective cohort study. SETTING: This study took place in 2 spinal minimally invasive centers in Beijing, China. METHODS: A multicenter retrospective study was conducted in consecutive patients diagnosed with symptomatic LDH receiving PTED or MED in 2 spinal minimally invasive centers from April 2009 to July 2016. A total of 1,053 patients were recruited, of which 632 underwent PTED and 421 underwent MED. All patients were followed with a minimum of 2 years; a set of clinical outcomes were extracted and analyzed. RESULTS: The operation time was similar between groups (71.2 ± 15.1 minutes in the PTED group and 69.4 ± 12.5 minutes in the MED group; P = 0.518); length of incision was significantly shorter; intraoperative blood loss was less in the PTED group (P < 0.001); hospital stay was 3.6 ± 1.5 days in the PTED group and 5.4 ± 2.8 days in the MED group with significant differences detected (P = 0.018); however, intraoperative fluoroscopy was longer with significantly higher cost with the PTED group (P < 0.001). Transient dysesthesia and wound complications were more common in the MED group (P = 0.039 and P = 0.026, respectively); however, no significant differences were found with total complications (P = 0.139). Significant lower Visual Analog Scale pain score (back and leg) were detected on day 1 postoperatively (P = 0.007 and P = 0.018, respectively). No significant differences were found at all other time points (P > 0.05). Significantly better Oswestry Disability Index (ODI) score was detected postoperatively at 1 month in the PTED group (19.6 ± 9.8 vs. 27.2 ± 9.3; P = 0.016); ODI score at other time points did not differ significantly between groups (P > 0.05). Modified MacNab criteria showed that most patients experienced excellent and good results with no significant differences between groups (P = 0.511). LIMITATION: This was a multicenter retrospective study wherein the surgeons may have introduced bias to the study. CONCLUSIONS: Both PTED and MED present to be an acceptable long-term efficacy for the treatment of LDH. Although PTED is associated with longer intraoperative fluoroscopy and a little more cost, it should still be considered superior to MED considering the benefits of lesser invasion, shorter hospital stays, quicker pain relief, and functional recovery.

[The role of capsaicin-sensitive primary afferents in experimental sciatic pain].

OBJECTIVES: To determine the effect of destroying capsaicin-sensitive primary afferents (CSPA) fibers on paw withdrawal mechanical threshold (PWMT) induced by the direct compression of L5 nerve root with autologous disc. METHODS: The procedure used autologous disc of the rats from the coccygeal intervertebral discs to apply direct pressure to the L5 dorsal root. PWMT was measured at the different time points post-surgery and pre-surgery. The changes in spatial expression pattern of c-fos protein in the spinal cord were also determined at 3 weeks when PWMT decreased to the peak. RESULTS: The pretreatment with capsaicin produced a complete prevention of mechanical hyperalgesia induced by disc compression. The direct compression of L5 nerve root produced an obvious expression of fos-like immunoreactivity neurons in the dorsal horn of the spinal cord, which was significantly decreased by pretreatment with capsaicin. CONCLUSIONS: The study shows that CSPA fibers, which mainly terminated in superficial layers of dorsal horn, may play a key role in mechanical hyperalgesia in the new sciatica model.

Risk factors for non-fusion segment disease after anterior cervical spondylosis surgery: a retrospective study with long-term follow-up of 171 patients.

BACKGROUND: The purpose of this study was to investigate the incidence and causes of non-fusion segment disease (NFSD), both adjacent and non-adjacent to a fused segment, after anterior cervical arthrodesis. METHODS: This is a single-center study. Between January 1998 and January 2011, two surgeons' 171 patients who had an anterior cervical decompression and fusion were followed clinically for more than 5 years. The correlation between the incidence of symptomatic non-fusion segment disease and the following clinical parameters (age at operation, fusion levels,) and radiological parameters (number of patients who had a plate, anterior cervical decompression and fusion (ACDF) or corpectomies, preoperative and postoperative cervical spine alignment, Pavlov's ratio at the C5 level, and preoperative existence of a non-fusion segment degeneration on magnetic resonance imaging) was evaluated. RESULTS: Of the 171 patients reviewed, 16 patients had non-fusion segment disease (9.36%), of which 12 had adjacent segment disease and 4 had non-adjacent segment disease. Postoperative cervical lordosis in the non-fusion segment disease group was significantly smaller than that of the disease-free group (P < 0.001). Fusion levels in the NFSD group were 1.69 whereas 2.26 in disease-free group (P = 0.005). The incidences of disc degeneration in unfused segments was more severe in the NFSD group than in the disease-free group (P = 0.004). The results of binary logistic regression showed that the major factor affecting NFSD is postoperative cervical lordosis (P = 0.000) followed by disc degeneration (P = 0.024). The other parameters did not show a statistically significant difference. CONCLUSIONS: The incidence of symptomatic non-fusion segment disease after anterior cervical arthrodesis has multifactorial causes. Postoperative cervical lordosis and disc degeneration in non-fusion segments were major factors in the incidence of NFSD.