Study DesignRetrospective Cohort Study.ObjectivesIn this study, we aimed to evaluate the risk factors associated with cancer-specific survival (CSS) of patients with spinal and pelvic diffuse large B-cell lymphoma (SP-DLBCL) and construct a competing risk-based model for predicting 3- and 5-year CSS.MethodsData on patients diagnosed between 2010 and 2019 were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. The total dataset was randomly divided into the training and testing datasets at a ratio of 7:3. Factors associated with CSS were identified by competing risk regression for the construction of a nomogram on the training dataset. Further, the testing dataset was used to validate the performance of the nomogram.ResultsCompeting risk regression revealed that age, Ann Arbor Stage, and chemotherapy were independent prognostic factors for CSS. The nomogram exhibited satisfactory agreement on calibration plots for the training and testing datasets. The nomogram performed well on the training and testing datasets, exhibiting a good clinical net benefit. Thus, a nomogram-based web calculator was constructed for clinical application.ConclusionIn this study, we evaluated the risk factors of CSS in patients with SP-DLBCL using competing risk regression analysis. The established nomogram and web-based tool performed well and could be used widely in clinical practice.

Tissue biopsy is the gold standard for differentiating osteoporotic vertebral compression fractures from malignant lesions. However, the necessity of routine biopsies during percutaneous vertebroplasty and kyphoplasty is debated due to the low malignancy detection rates. This study aims to identify key predictors of positive biopsy outcomes in patients undergoing these procedures, with the goal of refining biopsy selection criteria to enhance diagnostic yield and improve clinical decision-making. We conducted a retrospective cohort study involving 295 patients who underwent percutaneous vertebroplasty and kyphoplasty with biopsy between June and December 2023. Clinical data, including age, gender, fracture aetiology, imaging findings, and biopsy results, were collected. Binary logistic regression analysis was employed to identify significant predictors of positive biopsy outcomes. The biopsy results revealed an overall malignancy rate of 1.01

Study Design. Retrospective analysis. Objective. This study aimed to establish nomograms for predicting overall survival (OS) and cancer-specific survival (CSS) in patients with solitary plasmacytoma of the spine (SPS). Summary of Background Data. SPS is a rare type of malignant spinal tumor. A systematic study of prognostic factors associated with survival can provide guidance to clinicians and patients. Consideration of other causes of death (OCOD) in CSS will improve clinical practicability. Methods. A total of 1078 patients extracted from the SEER database between 2000 and 2018 were analyzed. Patients were grouped into training and testing data sets (7:3). Factors associated with OS and CSS were identified by Cox regression and competing risk regression, respectively, for the establishment of nomograms on a training data set. The testing data set was used for the external validation of the performance of the nomograms using calibration curves, Brier’s scores, C-indexes, time-dependent receiver operating characteristic curves, and decision curve analysis (DCA). Results. Age and grade were identified as factors associated with both OS and CSS, along with marital status, radiation for OS, and chemotherapy for CSS. Heart disease, cerebrovascular disease, and diabetes mellitus were found to be the 3 most common causes of OCOD. The nomograms showed satisfactory agreement on calibration plots for both training and testing data sets. Integrated Brier score, C-index, and overall area under the curve on the testing data set were 0.162/0.717/0.789 and 0.173/0.709/0.756 for OS and CSS, respectively. DCA curves showed a good clinical net benefit. Nomogram-based web tools were developed for clinical application. Conclusion. This study provides evidence for risk factors and prognostication of survival in SPS patients. The novel nomograms and web-based tools we developed demonstrated good performance and might serve as accessory tools for clinical decision-making and SPS management. Level of Evidence. 3

Our team designed a novel two-medium compatible bichannel endoscopy system for spinal surgery, V-shape bichannel endoscopy (VBE) system. Hereby, this study will introduce minimally invasive transforaminal lumbar interbody fusion (TLIF) with VBE system and report its preliminary clinical results. Fifty-two participants, who accepted VBE-assisted TLIF surgery (VBE-TLIF) in our hospital were included in this study. The duration of operation, off-bed time, and days of hospitalization were recorded. Besides, the patient’s preoperative and postoperative pain were evaluated via visual analog scale (VAS), the functional status was evaluated via Oswestry dysfunction index (ODI) and modified MacNab criteria. Patients were asked to follow-up in the outpatient department at the 3rd, 6th, 12th, and 24th month after surgery. X-ray or CT was examined to evaluate the internal fixation position and interbody fusion result. All patients received unilateral decompression with an average operation duration of 178.49 ± 27.49 min. After the surgery, their VAS score of leg pain and back pain reduced significantly. At the last follow-up, the VAS score of leg pain and back pain was 0.80 ± 0.69 and 0.86 ± 0.75 separately. The difference shows statistically significant with p < 0.05. At the last follow-up, the ODI was 15.20 ± 5.75. According to modified MacNab criteria, 39 patients rated their function as excellent, and 10 patients were good. The overall satisfaction rate reached 94

Implant failure caused by unsatisfying osseointegration is still a noteworthy clinical problem. Strontium (Sr) has been confirmed to be a bioactive element that facilitates bone growth. In this study, Sr was surface incorporated in titanium (Ti) implant with different contents. The XRD results demonstrated that Sr existed mainly in the form of SrTiO3. All Sr-contained implants showed sustainable Sr2+ release behavior. Meanwhile, the Sr2+ release rate was proportional to the Sr content. The in vitro immersing test showed that the apatite-forming ability on the implant surface was decreased with the increase of Sr content. Conversely, the cell experiments manifested that implants with high content of Sr were more favorable to cell spreading, proliferation, osteogenic differentiation, and extracellular matrix mineralization. The in vivo implant experiment revealed that Sr-incorporation could improve osseointegration, new bone formation and mineralization, and bone-implant bonding strength. In addition, Ti5Sr, which possessed a combined good osteogenic activity and apatite-forming ability, exhibited the best in vivo overall performance. In summary, we first put forward the competitive effect of osteogenic activity and apatite-forming ability on bone-implant osseointegration, which would provide a new strategy for implant design.

Purpose To evaluate the clinical features of and risk factors for recurrent lumbar disc herniation (rLDH) after percutaneous endoscopic lumbar discectomy (PELD) in our clinical practice. Methods A total of 942 consecutive patients who underwent single-level PELD from January 2013 to August 2019 were included. Patients were divided into the recurrence group and the nonrecurrence group. Patient characteristics, radiographic parameters and surgical variables were compared between the two groups. Univariate analysis and multiple logistic regression analysis were adopted to determine the risk factors for recurrence after PELD. Results The prevalence of rLDH was 6.05%. Age, sex, tobacco use, duration of low back pain, body mass index (BMI), occupational lifting, herniated disc type, facet joint degeneration, operation time and time to ambulation were significantly different between the two groups. Univariate analysis showed that age ( P < 0.001), sex ( P = 0.019), BMI ( P = 0.001), current smoking ( P < 0.001), occupational lifting ( P < 0.001), facet joint degeneration ( P = 0.001), operation time ( P = 0.002), and time to ambulation ( P < 0.001) could be significantly associated with the incidence of rLDH after PELD. Multivariate analysis suggested that an older age ( P < 0.001), the male sex ( P = 0.017), a high BMI ( P < 0.001), heavy work ( P = 0.003), grade II facet joint degeneration ( P < 0.001) and early ambulation ( P < 0.001) were significantly related to rLDH after PELD. Conclusions An older age, the male sex, a higher BMI, heavy work, grade II facet joint degeneration, and early ambulation are independent significant risk factors for rLDH after PELD. Great importance should be attached to these risk factors to prevent rLDH. We suggest that patients control their weight, avoid heavy work, ambulate at an appropriate time, and perform strengthening rehabilitation exercises to reduce the incidence of rLDH.

Abstract Purpose To describe the cervical spine morphology and explore its relationship to global sagittal alignment parameters in the asymptomatic adolescent population. Methods A total of 111 adolescent subjects were included. Sagittal alignment parameters, including C7 Slope, C2-C7 Cobb, C2-7 plumb line (PL), C2-S1 Sagittal Vertical Axis (SVA), C7-S1 SVA, T5-12 Cobb, T10-L2 Cobb, L1-S1 Cobb, pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS), were obtained from lateral radiographs. Results Forty-four males and sixty-seven females with a mean age of 16.12 ± 2.40 years were included in this study. The mean values of C7 Slope, C2-7 Cobb and C2-7PL were 20.45 ± 8.88°, -7.72 ± 12.10°, and 13.53 ± 11.63 mm, respectively. C2-7 Cobb, C7 Slope showed significant differences between the male and female groups. Correlation analysis showed that C7 slope was significantly correlated with C2-7 Cobb (r = -0.544, P < 0.001), C2-S1 SVA (r = 0.335, P < 0.001), and C7-S1 SVA (r = 0.310, P = 0.001), but not lumbosacral parameters(L5-S1 Cobb, PI, PT, SS). Using a modified method of Toyama to describe the cervical spine morphology, there were 37 cases (33.3%) in the Lordotic group, and C7 slope, C2-7 Cobb and C2-7PL showed significant differences between groups. According to C2-C7 Cobb, there were 80 Lordotic cases (72.1%). C7 slope and C2-7PL were significantly different between the two groups. Conclusion The cervical spine morphology of asymptomatic adolescents varies widely, from lordotic to kyphotic. Combining different classification methods provides a better understanding of the morphology of the cervical spine. C7 slope is an important predictor of global sagittal balance and C2-7PL is a key parameter for restoring cervical lordosis, which should be considered pre-operatively and for conservative treatment. Cervical regional sagittal alignment parameters are not correlated with lumbosacral parameters, and C2-7 Cobb, C7 Slope showed significant differences between males and females.

ObjectiveThe study introduced uniportal‐bichannel spinal endoscopic system (UBiSES) and explored the feasibility of applying UBiSES to conduct lumbar foraminoplasty in percutaneous endoscopic transforaminal discectomy (PETD).MethodsThis is a cohort study. 36 patients confirmed as L5/S1 lumbar disc herniation (LDH) in our hospital from March, 2019 to November, 2019 were enrolled. 36 patients were divided into two groups named the UBiSES group (n = 18, male: female = 8:10) and the TESSYS group (n = 18, male: female = 10:8). The average age of the UBiSES group and the TESSYS group were 40.94 ± 12.39 years old and 39.78 ± 13.02 years old respectively. PETD via uniportal‐bichannel foraminoplasty assisted by UBiSES was adopted on the UBiSES group while PETD via conventional foraminoplasty was performed on the TESSYS group. One experienced surgeon with more than 4000 cases of lumbar surgery performed PETD on all patients. The demographic data, the duration of working cannula placement (minutes), decompression time (minutes), radiation exposure time (seconds), complications, Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) scores and modified MacNab criteria were recorded and analyzed. The magnetic resonance imaging (MRI) and computed tomography (CT) were conducted to evaluate the radiographic improvement.ResultsPETD via lumbar foraminoplasty was successfully performed in all cases. The follow‐up points were 3 months, 6 months, and 12 months. The average follow‐up period of all patients was 15.78 ± 2.29 months. There was no statistic difference in age (P = 0.81), sex (P = 0.51) and follow‐up (P = 0.14) between two groups. The duration of working cannula placement was 19.08 ± 2.30 min in the UBiSES group and 24.90 ± 4.71 min in the TESSYS group and there was significant difference between two groups (P < 0.05). There was no statistic difference in decompression time between the UBiSES group (44.18 ± 5.70 min) and the TESSYS group (47.46 ± 5.96 min) (P = 1.70). The radiation exposure time was 28.00 ± 4.70 s in the UBiSES group and 40.50 ± 5.73 s in the TESSYS group respectively, and has significant difference between two groups (P < 0.05). Furthermore, there was significant different in the duration of working cannula placement and radiation exposure time in male or female between the UBiSES group and the TESSYS group (P < 0.05). For male or female, no difference observed in decompression time and follow‐up period between two groups. Postoperative VAS of low back and leg at every follow‐up point (1 day, 3 months, 6 months, 12 months) was improved significantly in both groups compared with their preoperative VAS (P < 0.05). The postoperative ODI (3 months, 6 months, 12 months) has decreased significantly in both the UBiSES group and the TESSYS group compared with their preoperative ODI (P < 0.05). 94.44% patients received an excellent or good recovery in the UBiSES group and 88.89% for the TESSYS group. There was no poor result reported in both groups. The radiographic images showed satisfactory foraminoplasty and sufficient decompression of nerve in both groups. No postoperative complications were observed during follow‐ups in the UBiSES group. Two patients in the TESSYS group experienced postoperative dysesthesia and the symptom was disappeared in 5 days and 7 days respectively with dexamethasone and neurotrophic drugs treatment.ConclusionsThe original designed UBiSES could effectively and safely enlarge the foramen with an extensive surgical view and space under full‐time and real‐time visualization and get satisfactory efficacy.

Initial implant-associated infection and later poor osseointegration are the main obstacles for bone implant success. Therefore, it is essential to endow implants with sequential antibacterial and osteogenic properties. However, bacteria and host cells share similar response mechanisms to external environments, so up to now, designing such implants remains a challenge. Here, we proposed a novel strategy of tailoring a time-varying surface alkaline microenvironment for sequential anti-infection and osteointegration, which was realized by constructing a two-layer hierarchical coating on the titanium with Ca-O-Ti as the inner layer and MgO as the outer layer. At the early stage of bone implantation, the outer MgO film rapidly generates a local strong alkaline microenvironment that disrupts bacterial energy metabolism and kills bacteria; at the later stage, the inner Ca-O Ti layer maintains a long-term local weak alkaline microenvironment, which promotes stem cell adhesion, proliferation, and osteogenic differentiation to achieve successful osteointegration. The results of an in vivo experiment using a rat osteomyelitis model confirmed that the hierarchical coating inhibited infection and promoted the formation of new bone. This study demonstrates the potential of tailoring a time-varying alkaline microenvironment for sequential anti-infection and osteointegration, as a promising and safe strategy for the surface modification of bone implants.

BACKGROUND Percutaneous endoscopic lumbar discectomy (PELD) has become one of the most popular minimally invasive surgeries for lumbar disc herniation (LDH), however, very highly migrated LDH is still a tricky issue for PELD. This study reported a new endoscopic discectomy strategy for the treatment of very highly migrated LDH between the L4/5 and L5/S1 level. MATERIAL AND METHODS The current study retrospectively analyzed 12 patients who accepted PELD for very highly migrated LDH between the L4/5 and L5/S1 level. Under local anesthesia, the transforaminal approach was chosen for the L4/5 level and the interlaminar approach was chosen for the L5/S1 level. The 10-point visual analogue scale (VAS) was used to assess back pain (VAS-Back) and leg pain (VAS-Leg). Oswestry disability index (ODI) and Modified Mac Nab Criteria were adopted as the functional evaluation methods. All patients were followed in the outpatient department for at least 12 months after their operation. RESULTS Our study showed that very highly migrated disc between L4/5 and L5/S1 level could be removed completely by this strategy. Except for 1 case of postoperative dysesthesia and 1 case of dural tear, no severe complication occurred. At the last follow-up, the average VAS-Back score of the study patients was reduced from 5.17±2.12 to 2.08±1.08 (P<0.05) and the average VAS-Leg score was reduced from 7.25±1.48 to 1.33±0.89 (P<0.05). The average ODI scores improved from 48.50±10.59 to 13.00±2.76 (P<0.05). According to the Modified Mac Nab Criteria, 83.33% of patients (10 out of 12 patients) received an excellent or good recovery and no poor result was reported. No recurrence was observed during follow up. CONCLUSIONS PELD via a transforaminal and interlaminar combined approach provides an alternative option for select patients with very highly migrated LDH between the L4/5 and L5/S1 level.

Objectives Transforaminal percutaneous endoscopic discectomy (TPED) is one of the most commonly used minimally invasive spine surgeries around the world. However, conventional surgical planning and intraoperative procedures for TPED have relied on surgeons’ experience, which limits its standardization and popularization. Virtual reality (VR) is a novel technology for pre‐surgical planning in various fields of medicine, while isocentric navigation can guide intraoperative procedures for TPED. The present study aimed to explore the feasibility of applying VR combined with isocentric navigation in TPED on cadavers. Methods The surgical levels were L 3 /L 4 and L 4 /L 5 as well as L 5 /S 1 of both sides of each cadaver specimen. First, the surgeon manually conducted the above procedures on the left side of every specimen without preoperative simulation and isocentric navigation (Group A). Then the same surgeon conducted the VR simulation for surgical planning of the right side (Group B). After VR simulation, the same surgeon made the percutaneous punctures and placed the working channel on the right side of the specimen at all levels. Results At the L 3 /L 4 level, the puncture‐channel time was 11.36 ± 2.13 min in Group A and 11.29 ± 2.23 min in Group B ( t = 0.097, P = 0.938). The exposure time was 17.21 ± 2.91 s in Group A and 14.64 ± 1.60 s in Group B ( t = 2.534, P = 0.025). At the L 4 /L 5 level, the puncture‐channel time was 13.86 ± 3.90 min in Group A and 11.93 ± 2.95 min in Group B ( t = 2.291, P = 0.039). Exposure time was 20.64 ± 3.84 s in Group A and 16.43 ± 2.47 s in Group B ( t = 6.118, P < 0.01). There were 7 patients undergoing foraminotomy in Group A and 3 patients undergoing foraminotomy in Group B ( t = 2.280, P = 0.236). At the L 5 /S 1 level, the puncture‐channel time was 18.21 ± 1.85 min in Group A and 15.71 ± 3.20 min in Group B ( t = 2.476, P = 0.028). Exposure time was 26.07 ± 3.17 s in Group A and 22.50 ± 2.68 s in Group B ( t = 2.980, P = 0.011). There were 14 patients receiving foraminotomy in Group A and 13 patients receiving foraminotomy in Group B ( t = 1.000, P = 1.000). Conclusions Virtual reality combined with isocentric navigation is feasible in TPED. It enables precise surgical planning and improves intraoperative procedures, and has the potential for application in clinical practice.

OBJECTIVE: In percutaneous endoscopic transforaminal discectomy (PETD), surgeons are exposed to intraoperative radiographic radiation over a long-term career, which may he correlated with high risk of iatrogenic radiation hazards. The purpose of this prospective cohort study was to assess the impact of concentric stereotactic technique on radiation exposure to surgeons in PETD. METHODS: Patients who underwent conventional PETD were regarded as group A, whereas those undergoing PETD with concentric stereotactic technique were considered as group B. The primary outcomes were cumulative radiation dose to the surgeon's eye, thyroid gland, and breast. RESULTS: A total of 34 patients were treated in group A and 30 patients were treated in group B. The cumulative radiation dose of the eye per operation was 0.017 (0.58/34) mSv in group A and 0.010 (0.31/30) mSv in group B, which meant a reduction of 41.18/0. The cumulative radiation dose of the thyroid gland per operation was 0.018 (0.60/34) mSv in group A and 0.011 (0.33/30) mSv in group B, which meant a reduction of 38.89%. The cumulative radiation dose of the chest per operation was 0.039 (1.33/34) mSv in group A and 0.023 (0.70/30) mSv in group B, which meant a reduction of 41.03%. There were no significant differences in hospital stay, visual analog scale score of waist and leg pain, Oswestry Disability Index score, MacNab satisfaction, and complications between the 2 groups (P> 0.05). CONCLUSIONS: The concentric stereotactic technique can effectively reduce radiation exposure to surgeons by about 40%.

OBJECTIVES: The present study introduced ultrasound volume navigation (UVN) to reduce the radiation exposure and puncture time of percutaneous transpedicular puncture in percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP). METHODS: We retrospectively reviewed the medical records of patients with osteoporotic vertebral compression fracture who had undergone PVP or PKP guided by UVN or fluoroscopy from September 2017 to December 2017. RESULTS: We enrolled 10 patients (6 women, 4 men) with 24 pedicles involved in the present study. Significant reductions in fluoroscopy frequency (2.58 vs. 17.42; P < 0.01), exposure time (2.36 vs. 15.69 seconds; P < 0.01), and puncture time (4.13 vs. 1921 minutes; P < 0.01) for each pedicle were observed in the UVN group compared with the fluoroscopy group. Obvious correlations among fluoroscopy frequency, exposure time, and puncture time for each pedicle were observed (P < 0.01). The visual analog scale scores and Oswestry Disability Index were both significantly improved after the procedures. All patients achieved excellent or good clinical outcomes. No complications were observed in any patient. CONCLUSIONS: UVN could obviously reduce the radiation exposure and puncture time of percutaneous transpedicular puncture in PVP and PKP.

Purpose To compare the efficacy and safety of two different surgical incisions for minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the management of two-level degenerative lumbar diseases. Methods We conducted a retrospective study of 129 patients, who underwent two-level MIS-TLIF for degenerative lumbar diseases from September 2014 to December 2015. Sixty-two patients underwent MIS-TLIF with unilateral long decompression incision (group A) and 67 patients underwent MIS-TLIF with bilateral short decompression incision (group B). Demographics and peri-operative clinical data were collected from medical records. Radiographic fusion, visual analog scale for leg pain (VAS-LP), back pain (VAS-BP), the Oswestry Disability Index (ODI), and MacNab satisfaction were compared between two groups. Results Patients in group A experienced significantly longer operative time (P=0.019), more estimated blood loss (P=0.002), and radiation exposure (P<0.001) than those in group B. However, no statistical differences were detected between two groups in blood transfusion (P=0.845) or hospital stay (P=0.690). Besides, VAS-BP, VAS-LP, and ODI significantly improved in both groups after the surgery, but no significant differences were observed between two groups pre-operatively, three day post-operatively, or at the last follow-up. Moreover, there were no distinct differences between two groups in total complication rate (P=0.653), fusion rate (P=0.822), or MacNab satisfaction (P=1.000) at the last follow-up. Conclusions In two-level degenerative lumbar diseases, based on the bilateral decompression via unilateral approach technique, MIS-TLIF with bilateral short decompression incision could significantly reduce radiation exposure, shorten operative time, decrease blood loss, and achieve comparable clinical outcomes when compared to unilateral long decompression incision.

OBJECTIVE: Ultrasound volume navigation (UVN) has been widely used for accurate guidance and decreased radiation exposure. However, few studies have focused on the clinical significance of UVN in guiding percutaneous puncture in percutaneous transforaminal endoscopic discectomy (PTED). We evaluated UVN to guide percutaneous puncture in PTED. METHODS: We retrospectively reviewed the medical records of 12 patients (8 men and 4 women), who had undergone PTED with the help of UVN or fluoroscopic guidance for lumbar disc herniation from November 2017 to December 2017. RESULTS: The age of these 12 patients range was 26-71 years, and the body mass index range was 18.19-26.91 kg/m(2). Of the 12 patients, 6 were in UVN group and 6 were in fluoroscopy group. The mean number of punctures was 1.00 in UVN group and 3.83 in fluoroscopy group. The mean exposure time was 3.60 and 13.80 seconds in UVN and fluoroscopy groups, respectively. The mean operation time was 48.17 minutes and 61.33 minutes in UVN and fluoroscopy groups, respectively. A positive relationship was found between operation time and exposure time (P < 0.05). All patients achieved excellent or good clinical outcomes. The Oswestry Disability Index and visual analog scales for leg pain and back pain all showed significant improvement after the procedure (P < 0.05). None of patients experienced a complication. CONCLUSIONS: UVN decreased the number of puncture attempts, radiation exposure, and operation time compared with fluoroscopic guidance in PTED. Therefore, UVN is a feasible and efficient method for guiding percutaneous puncture in PTED.

Background: The use of percutaneous endoscopic lumbar discectomy (PELD) is increasing in the treatment of lumbar disc herniations (LDH). Nerve and vessel injury may happen during the establishment of the transforaminal working channel. Also, there is usually exposure to intraop radiation when the C-arm is used to help establish the location of the transforaminal working channel. Objective: To evaluate the accuracy and safety of the volume navigation technique for guiding transforaminal puncture in cadaver and clinical patient treatment. Study Design: Cadaver experiment and comparative clinical research. Setting: Changhai Hospital, the Second Military Medical University. Method: Volume navigation guided transforaminal puncture was performed in 15 cadavers. The registration error, time of overall puncture, ultrasound (US) observed distance between needle tip and target (DNT), and puncture error were recorded. Clinical research was performed in 63 patients who had undergone PELD. Comparative research was done between 2 groups. Those who had transforaminal puncture carried out under C-arm guidance (n = 30), and those patients whose transforaminal puncture was carried out under volume navigation guidance (n = 33). Puncture times and frequency of fluoroscopy were recorded. Both groups were evaluated with Oswestry Disability Index (ODI), and visual analog scale (VAS) before surgery at 1, 3, and 6 months, and 1 year post-surgery. Results: In the cadaver experiment, mean registration error was 2.66 +/- 1.10 mm; DNT 20.08 +/- 1.32 mm; puncture error 2.91 +/- 1.29 mm; overall time of puncture 22.10 +/- 5.20 min. In the clinical patient research, puncture times and frequency of fluoroscopy were significantly lower in the volume navigation group compared with the C-arm group (P < 0.001). There were no significant differences between the 2 groups in ODI and VAS scores (P > 0.05) at different time points. Limitations: The correlation between the registration errors and the puncture errors requires further analysis. Also, due to the relatively small number of cases studied, additional cases need to be collected to obtain reliable results. Conclusion: The volume navigation technique can be used for PELD because it helps to guide percutaneous posterolateral transforaminal puncture accurately with reduced puncture times and intraop radiation.

OBJECTIVE: To evaluate short-term efficacy and safety of percutaneous transforaminal endoscopic discectomy (PTED) in treatment of symptomatic adjacent segment disease (ASD) after lumbar fusion in elderly patients >65 years old. METHODS: Patients >65 years old who underwent PIED for ASD after lumbar fusion between January 2013 and September 2016 were retrospectively evaluated. Demographics and perioperative clinical data were collected from medical records. MacNab classification, visual analog scale, Oswestry Disability Index, and Japanese Orthopaedic Association scores as well as 36-Item Short-Form Health Survey were used to assess the efficacy of PTED. RESULTS: We evaluated 25 consecutive patients >65 years old with ASD (11 men, 14 women; mean age 74.65 +/- 9.61 years). Mean follow-up time was 37.14 + 11.60 months. Of patients, 84.0% (21/25) had excellent or good clinical outcomes, 12.0% (3/25) had fair outcomes, and 4.0% (1/25) had poor outcomes. Complications included 1 dural laceration, 1 postoperative dysesthesia, and 1 recurrence. For patient-reported outcomes, significant improvements were observed postoperatively compared with preoperatively in visual analog scale (P < 0.05), Oswestry Disability Index (P < 0.05), Japanese Orthopaedic Association (P < 0.05), and 36-Item Short-Form Health Survey (P < 0.05). CONCLUSIONS: PTED demonstrated satisfactory shortterm efficacy and safety in management of ASD after lumbar fusion in patients >65 years old. PTED may be an alternative choice for elderly patients with ASD after lumbar fusion.

[Objective] To investigate effect of using concentric sphere navigation device (CSND) on radiation exposure and radiation-related disease in percutaneous transforaminal endoscopic lumbar discectomy (PTELD).[Method]This study retros pectively assessed the medical records of 127 patients who underwent PTELD from October2015 to August 2016.Of them,64 patients who received the puncture using CSND were regarded as the navigation group,while the remaining 63 patients who underwent the conventional puncture methods were considered as the routine group.Puncture times,fluoroscopic times,time of radiation exposure,operation time,estimated radiation dose and risk of relative disease were compared between the 2 groups.[Result] There were statistically significant differences between the navigation group and the routine group in the average puncture times (1.59±0.66 versus 4.83±1.76,P＜0.001),the total fluoroscopic times (27.38±5.11 versus 36.97± 7.52,P＜0.001),the total exposure time (26.27 ±4.75 s versus 33.51 ±7.08 s,P＜0.001) and the operation time (62.91± 10.03 min versus 69.84± 10.49 min,P＜0.001).In addition,the navigation group was significantly inferior to the routine group in the estimated radiation dose (0.49t0.09 mSv versus 0.63±0.14 mSv,P＜0.001),the estimated risk of cancer [(26.75± 4.89) ×10-9 versus (34.39±7.50) ×10-9,P＜0.001] and the estimated risk of genetic diseases [(0.97±0.18) ×10-9 versus (1.25±0.27) × 10-9,P＜0.001].However,there was no significant difference in ratios of satisfaction and complication between the two groups (P＞0.05).[Conclusion] The concentric sphere navigation device does significantly improve the puncture accuracy,decrease the operation time and radiation exposure as well,which might reduce the risks of cancer and genetic disease.

BACKGROUND:Posterolateral endoscopic trasforaminal discectomy (PELD) requires an ideal percutaneous puncture to place the working channel for endoscopic discectomy. The conventional blinded puncture relies on the surgeon's experience and repeated fluoroscopy, which may increase radiation exposure. This study aimed to introduce isocentric navigation to plan trajectory and guide punctures in PELD.METHODS:Technical note and clinical outcomes of patients undergoing PELD with isocentric navigation were recorded in this report.RESULTS:Four patients (3 female, 1 male) were included in this study. Age ranged from 21 to 67 years, and the body mass index ranged from 18.71 to 23.15 kg/m2. All of the included patients received just one puncture, and the radiation exposure time ranged from 15 to 40 seconds. The operation time ranged from 58 to 75 minutes, and no significant complications were observed. All patients reported significant pain relief and improved surgical outcomes, as assessed by the Oswestry Disability Index and Macnab criteria.CONCLUSIONS:Isocentric navigation is feasible in planning the trajectory and guiding the punctures in PELD and could be considered as a potential practical tool to facilitate surgery.

Abstract The conventional location methods for minimally invasive spinal surgery (MISS) were mainly based on repeated fluoroscopy in a trial-and-error manner preoperatively and intraoperatively. Localization system mainly consisted of preoperative applied radiopaque frame and intraoperative guiding device, which has the potential to minimize fluoroscopy repetition in MISS. The study aimed to evaluate the efficacy of a novel lumbar localization system in reducing radiation exposure to patients. Included patients underwent minimally invasive transforaminal lumbar interbody fusion (MISTLIF) or percutaneous transforaminal endoscopic discectomy (PTED). Patients treated with novel localization system were regarded as Group A, and patients treated without novel localization system were regarded as Group B. For PTED, The estimated effective dose was 0.41 ± 0.13 mSv in Group A and 0.57 ± 0.14 mSv in Group B (P < .001); the fluoroscopy exposure time of PTED was 22.18 ± 7.30 seconds in Group A and 30.53 ± 7.56 seconds in Group B (P < .001); The estimated cancer risk of radiation exposure was 22.68 ± 7.38 (10–6) in Group A and 31.20 ± 7.96 (10–6) in Group B (P < .001). For MISTLIF, the estimated effective dose was 0.45 ± 0.09 mSv in Group A and 0.58 ± 0.09 mSv in Group B (P < .001); The fluoroscopy exposure time was 25.41 ± 5.52 seconds in Group A and 32.82 ± 5.03 seconds in Group B (P < .001); The estimated cancer risk was 24.90 ± 5.15 (10–6) in Group A and 31.96 ± 5.04 (10–6) in Group B (P < .001). There were also significant differences in localization time and operation time between the 2 groups either for MISTLIF or PTED. The lumbar localization system could be a potential protection strategy for minimizing radiation hazards.