The Spectrum of Presumed Tubercular Uveitis in a Referral Eye Clinic in Qatar.

PURPOSE: To analyze the clinical spectrum of patients with presumed tubercular uveitis in a referral eye clinic in Qatar. METHODS: We retrospectively reviewed the clinical records of 50 patients (80 eyes) diagnosed with presumed ocular tuberculosis who presented to the uveitis clinic, department of Ophthalmology Hamad Medical Corporation, Qatar, from January 2014 till December 2019. RESULTS: Mean age at presentation was 34.5 ± 9.3 years. Forty one patients were males (82%) and 30 patients had bilateral involvement (60%). Forty eyes (50%) had posterior uveitis, 21 eyes (26.3%) intermediate uveitis, 11 eyes (13.7%) panuveitis, and 8 eyes (10%) anterior uveitis. Ocular findings included vitritis in 82.5% of eyes, retinal vasculitis in 46.3% (92% of which were occlusive in nature), multifocal choroiditis in 18.8%, serpiginous-like choroiditis in 11.3%, Most common complications at presentation or during follow-up included macular edema in 32 eyes (40%), preretinal or optic disc neovascularization in 29 eyes (36.3%) and vitreous hemorrhage in 17 eyes (21.3%). Anti-tubercular treatment was provided to 46 patients (92%). Systemic corticosteroids and corticosteroid sparing agents were associated, respectively, in 39 patients (78%) and 14 patients (28%). After 1 year of follow up, inflammation was controlled, with a significant improvement in visual acuity (p < 0.0001). CONCLUSIONS: In Qatar, tubercular uveitis has a broad spectrum of ocular features, with posterior and intermediate uveitis being the most common anatomic forms. Vitritis, multifocal choroiditis without or with a serpiginous-like pattern, and occlusive retinal vasculitis are the most common ocular findings. Main sight-threatening ocular complications are macular edema, posterior segment neovascularization, and vitreous hemorrhage.

Magnetic Resonance Imaging-Related Anatomic and Functional Parameters for the Diagnosis and Prognosis of Chiari Malformation Type I: A Systematic Review and Meta-analysis.

OBJECTIVE: Imaging parameters of Chiari malformation type I (CMI) development are not well established. This study aimed to collect evidence of general or specific imaging measurements in patients with CMI, analyze indicators that may assist in determining the severity of CMI, and guide its diagnosis and treatment. METHODS: A comprehensive search was conducted across various databases including the Cochrane Library, PubMed, MEDLINE, Scopus, and Embase, covering the period from January 2002 to October 2023, following predefined inclusion criteria. Meta-analyses were performed using RevMan (ver. 5.4). We performed a quantitative summary and systematic analysis of the included studies. This study was registered in the PROSPERO (International Prospective Register of Systematic Reviews) prior to initiation (CRD42023415454). RESULTS: Thirty-three studies met our inclusion criteria. The findings indicated that out of the 14 parameters examined, 6 (clivus length, basal angle, Boogard's angle, supraocciput lengths, posterior cranial fossa [PCF] height, and volume) exhibited significant differences between the CMI group and the control group. Furthermore, apart from certain anatomical parameters that hold prognostic value for CMI, functional parameters like tonsillar movement, obex displacement, and cerebrospinal fluid dynamics serve as valuable indicators for guiding the clinical management of the disease. CONCLUSION: We collated and established a set of linear, angular, and area measurements deemed essential for diagnosing CMI. However, more indicators can only be analyzed descriptively for various reasons, particularly in prognostic prediction. We posit that the systematic assessment of patients' PCF morphology, volume, and other parameters at a 3-dimensional level holds promising clinical application prospects.

An Analysis of Optic Disc Parameters in Patients with Peripheral Retinal Tears Following Acute Posterior Vitreous Detachment: A Cross-Sectional Study.

Background: To investigate association between optic disc parameters analyzed by optical coherence tomography (OCT) and occurrence of peripheral retinal tears in patients with symptomatic posterior vitreous detachment (PVD). Methods: This cross-sectional study enrolled 75 patients with symptoms of acute PVD, who were allocated into two groups based on whether a peripheral retinal tear occurred or not. Results: When comparing the average retinal nerve fiber layer (RNFL) thickness (µm) between retinal tear and control groups, it was shown that patients with a retinal tear have a significantly higher (87.18 [95% confidence interval (CI), 84.47 to 89.9] vs 81.14 [95% CI, 77.81 to 84.46], P = 0.005) average RNFL thickness. Furthermore, we observed a significant difference (0.13, 0.06 to 0.22 vs 0.07, 0.04 to 0.1, P = 0.036, Mann-Whitney U-test) in the size of cup volume (mm3) between the tear and control groups, respectively. Linear regression showed a significant decrease (P = 0.029) in average RNFL thickness with increasing age, but without a significant difference between the two groups. There was no statistically significant difference between the tear and control groups in terms of rim area, disc area, and average cup-to-disc ratio. Conclusion: Patients with a higher average RNFL thickness and larger cup volume measured by OCT were more prone to develop a peripheral retinal tear. Increased peripapillary average RNFL thickness due to trauma and subsequent inflammation, possibly related to the more adherent posterior hyaloid membrane to the retina, may also indicate strengthened adhesions in the areas of the peripheral retina where retinal tears occur. OCT analysis of the optic nerve head may be used in everyday clinical practice as a predictor of the development of peripheral retinal tears in patients with symptomatic PVD.

A comparative cohort study of surgical approaches for adult spinal deformity at a minimum 2-year follow-up.

STUDY DESIGN: This study was a retrospective multi-center comparative cohort study. MATERIALS AND METHODS: A retrospective institutional database of operative adult spinal deformity patients was utilized. All fusions > 5 vertebral levels and including the sacrum/pelvis were eligible for inclusion. Revisions, 3 column osteotomies, and patients with < 2-year clinical follow-up were excluded. Patients were separated into 3 groups based on surgical approach: 1) posterior spinal fusion without interbody (PSF), 2) PSF with interbody (PSF-IB), and 3) anteroposterior (AP) fusion (anterior lumbar interbody fusion or lateral lumbar interbody fusion with posterior screw fixation). Intraoperative, radiographic, and clinical outcomes, as well as complications, were compared between groups with ANOVA and χ2 tests. RESULTS: One-hundred and thirty-eight patients were included for study (PSF, n = 37; PSF-IB, n = 44; AP, n = 57). Intraoperatively, estimated blood loss was similar between groups (p = 0.171). However, the AP group had longer operative times (547.5 min) compared to PSF (385.1) and PSF-IB (370.7) (p < 0.001). Additionally, fusion length was shorter in PSF-IB (11.4) compared to AP (13.6) and PSF (12.9) (p = 0.004). There were no differences between the groups in terms of change in alignment from preoperative to 2 years postoperative. There were no differences in clinical outcomes. While postoperative complications were largely similar between groups, operative complications were higher in the AP group (31.6%) compared to the PSF (5.4%) and PSF-IB (9.1) groups (p < 0.001). CONCLUSION: While there were differences in intraoperative outcomes (operative time and fusion length), there were no differences in postoperative clinical or radiographic outcomes. AP fusion was associated with a higher rate of operative complications.

Perioperative complications and cost of posterior decompression with fusion in thoracic spine for ossification of the posterior longitudinal ligament and ossification of the ligamentum flavum -a comparative study using a national inpatient database.

BACKGROUND: Although posterior decompression with fusion (PDF) are effective for treating thoracic myelopathy, surgical treatment has a high risk of various complications. There is currently no information available on the perioperative complications in thoracic ossification of the longitudinal ligament (T-OPLL) and thoracic ossification of the ligamentum flavum (T-OLF). We evaluate the perioperative complication rate and cost between T-OPLL and T-OLF for patients underwent PDF. METHODS: Patients undergoing PDF for T-OPLL and T-OLF from 2012 to 2018 were detected in Japanese nationwide inpatient database. One-to-one propensity score matching between T-OPLL and T-OLF was performed based on patient characteristics and preoperative comorbidities. We examined systemic and local complication rate, reoperation rate, length of hospital stays, costs, discharge destination, and mortality after matching. RESULTS: In a total of 2,660 patients, 828 pairs of T-OPLL and T-OLF patients were included after matching. The incidence of systemic complications did not differ significantly between the T-OPLL and OLF groups. However, local complications were more frequently occurred in T-OPLL than in T-OLF groups (11.4% vs. 7.7% P = 0.012). Transfusion rates was also significantly higher in the T-OPLL group (14.1% vs. 9.4%, P = 0.003). T-OPLL group had longer hospital stay (42.2 days vs. 36.2 days, P = 0.004) and higher medical costs (USD 32,805 vs. USD 25,134, P < 0.001). In both T-OPLL and T-OLF, the occurrence of perioperative complications led to longer hospital stay and higher medical costs. While fewer patients in T-OPLL were discharged home (51.6% vs. 65.1%, P < 0.001), patients were transferred to other hospitals more frequently (47.5% vs. 33.5%, P = 0.001). CONCLUSION: This research identified the perioperative complications of T-OPLL and T-OLF in PDF using a large national database, which revealed that the incidence of local complications was higher in the T-OPLL patients. Perioperative complications resulted in longer hospital stays and higher medical costs.

Cerebral hypometabolism in a pediatric patient with clinically resolved posterior reversible encephalopathy syndrome.

A 4-year-old boy with Nuclear factor-kappa B Essential Modulator deficiency syndrome presented with encephalopathy post haematopoietic stem cell transplantation. MRI demonstrated T2/FLAIR-hyperintensities in the posterior cerebral cortex concerning for posterior reversible encephalopathy syndrome. Clinical improvement was appreciated following withdrawal of the suspected offending pharmacological agent (Cyclosporine). An 18F-FDG PET/CT performed 2 months later to screen for post-transplant lymphoproliferative disease demonstrated markedly reduced FDG uptake in the posterior cerebral cortex, involving the parietal and occipital lobes. We describe, to the best of our knowledge, the first case of profound cerebral hypometabolism in a child with clinically resolved posterior reversible encephalopathy syndrome.

A rare case of a huge malignant pleural mesothelioma presenting in the posterior mediastinum.

We report a case of a 69-year-old woman with pleural mesothelioma presenting in the posterior mediastinum with a maximum diameter of 25 cm. She had a chronic cough and a pleural effusion was noted on chest X-ray. The examination of the effusion showed high hyaluronic acid levels, and mesothelioma was suspected. A chest computed tomography scan showed a huge mediastinal mass, which caused rapid progression of respiratory failure and compression of the heart. Sufficient tissue samples could not be obtained before death. The patient died approximately 1 month after the initial visit, and a pathological autopsy was performed. The diagnosis of malignant pleural mesothelioma was made. Malignant pleural mesothelioma with a huge posterior mediastinal mass such as in this case is considerably rare; however, it is a rapidly progressing form of the disease and is reported here as an important differential diagnosis for mediastinal tumours.

Posterior wall ablation for persistent atrial fibrillation: Very-high-power short-duration versus standard-power radiofrequency ablation.

Background: Posterior wall ablation (PWA) is commonly added to pulmonary vein isolation (PVI) during catheter ablation (CA) of persistent atrial fibrillation (AF). Objective: The purpose of this study was to compare PVI plus PWA using very-high-power short-duration (vHPSD) vs standard-power (SP) ablation index-guided CA among consecutive patients with persistent AF and to determine the voltage correlation between microbipolar and bipolar mapping in AF. Methods: We compared 40 patients undergoing PVI plus PWA using vHPSD to 40 controls receiving PVI plus PWA using SP. The primary efficacy endpoint was recurrence of atrial tachyarrhythmias after a 3-month blanking period. The primary safety outcome was a composite of major complications within 30 days after CA. In the vHPSD group, high-density mapping of the posterior wall was performed using both a multipolar catheter and microelectrodes on the tip of the ablation catheter. Results: PVI was more commonly obtained with vHPSD compared to SP ablation (98%vs 75%; P = .007), despite shorter procedural and fluoroscopy times (P <.001). Survival free from recurrent atrial tachyarrhythmias at 18 months was 68% and 47% in the vHPSD and SP groups, respectively (log-rank P = .071), without major adverse events. The vHPSD approach was significantly associated with reduced risk of recurrent AF at multivariable analysis (hazard ratio 0.39; P = .030). Microbipolar voltage cutoffs of 0.71 and 1.69 mV predicted minimum bipolar values of 0.16 and 0.31 mV in AF, respectively, with accuracies of 0.67 and 0.88. Conclusion: vHPSD PWA plus PVI may be faster and as safe as SP CA among patients with persistent AF, with a trend for superior efficacy. Adapted voltage cutoffs should be used for identifying atrial low-voltage areas with microbipolar mapping.

Effect of surface-modified intraocular lenses on long-term postoperative inhibition of posterior capsule opacification.

We compared the posterior capsule opacification incidences at 5 years postoperatively and the neodymium-yttrium-aluminum-garnet capsulotomy rates at 10 years postoperatively for two types of intraocular lenses with different optical properties and shapes. This randomized, controlled, prospective, single-blinded study with intra-individual comparisons was conducted between July 21, 2009, and August 31, 2011, at the Dokkyo Medical University Hospital, Tochigi, Japan. Thirty patients (60 eyes) underwent bilateral cataract surgery and received a XY1 intraocular lens in one eye and a FY-60AD intraocular lens in the other. Both intraocular lenses are acrylic and manufactured by HOYA. The XY1 lens is a single-piece, tinted intraocular lens featuring an ultraviolet/ozone treatment on the posterior surface of the lens optic, aimed at enhancing posterior capsule adhesion to prevent posterior capsule opacification. Conversely, the FY-60AD is a tinted intraocular lens with modified polymethylmethacrylate C-loops and no ultraviolet/ozone treatment of the optic. Scheimpflug images were taken using EAS-1000 (NIDEK Co., Ltd., Aichi, Japan), and the scattered light intensity (computer compatible tape) on the posterior surface of the intraocular lens was calculated and evaluated as the posterior capsule opacification. The scattered light values of the XY1 and FY-60AD groups were 6.50 ± 5.69 and 11.64 ± 5.30 computer compatible tape, respectively, at 5 years postoperatively. The cumulative survival incidence after neodymium-yttrium-aluminum-garnet laser capsulotomy was 74.8 % in the XY1 group and 13.8 % in the FY-60AD group at 10 years postoperatively. The surface-modified intraocular lens XY1 reduced the incidence of posterior capsule opacification even 10 years after surgery. Surface modification to increase the adhesion between the intraocular lens and the capsule effectively prevents posterior capsule opacification.

Transforaminal versus posterior lumbar interbody fusion for symptomatic single-level spondylolisthesis (LIFT): a multicentre controlled, patient blinded, randomised non-inferiority trial.

Background: The effectiveness of transforaminal lumbar interbody fusion (TLIF) compared to posterior lumbar interbody fusion (PLIF) in patients with single-level spondylolisthesis has not been substantiated. To address the evidence gap, a well-powered randomized controlled non-inferiority trial comparing the effectiveness of TLIF with PLIF, entitled the Lumbar Interbody Fusion Trial (LIFT), was conducted. Methods: In a multicenter randomized controlled non-inferiority trial among five Dutch hospitals, 161 patients were randomly allocated to either TLIF or PLIF (1:1), stratified according to study site. Patients and statisticians were blinded for group assignment. All patients were over 18 years old with symptomatic single-level degenerative, isthmic or iatrogenic lumbar spondylolisthesis, and eligible for lumbar interbody fusion surgery through a posterior approach. The primary outcome was change in disability measured with the Oswestry Disability Index (ODI) from preoperative to one year postoperative. The non-inferiority limit was set to 7.0 points based on the MCID of ODI. Secondary outcomes were change in quality-adjusted life years (QALY) assessed with EuroQol 5 Dimensions, 5 Levels (EQ-5D-5L) and Short Form Health Survey (SF-36), as well as back and leg pain (Numerical rating scale, NRS), anxiety and depression (Hospital Anxiety Depression Scale; HADS), perioperative blood loss, duration of surgery, duration of hospitalization, and complications. Trial registration: Netherlands Trial Registry, number 5722 (registration date March 30, 2016), Lumbar Interbody Fusion Trial (LIFT): A randomized controlled multicenter trial for surgical treatment of lumbar spondylolisthesis. Findings: Patients were included between August 2017 and November 2020. The total study population was 161 patients. Total loss-to-follow-up after one year was 16 patients. Per-protocol analysis included 66 patients in each group. In the TLIF group (mean age 61.6, 36 females), ODI improved from 46.7 to 20.7, whereas in the PLIF group (mean age 61.9, 41 females), it improved from 46.0 to 24.9. This difference (-4.9, 90% CI -12.2 to +2.4) did not reach the non-inferiority limit of 7.0 points in ODI. A significant difference in the secondary outcome measurement, QALY (SF-36), was observed in favor of TLIF (P < 0.05). However, this was not clinically relevant. No difference was found for all other secondary outcome measurements; PROMs (EQ-5D, NRS leg/back, HADS), perioperative blood loss, duration of surgery, duration of hospitalization, and perioperative and postoperative complications. Interpretation: For patients with single-level spondylolisthesis, TLIF is non-inferior to PLIF in terms of clinical effectiveness. Disability (measured with ODI) did not differ over time between groups. Funding: No funding was received for this trial.

Correlation between bony structures of the posterior cranial fossa and the occurrence of hemifacial spasm.

Objective: To quantitatively study the measurement data related to the bony posterior cranial fossa and explore the correlation between bony posterior cranial fossa morphology and the occurrence of hemifacial spasm. Methods: A total of 50 patients with hemifacial spasm who attended the Department of Neurosurgery of China-Japan Friendship Hospital from October 2021 to February 2022 were included, and 60 patients with minor head trauma excluding skull fracture and intracranial abnormalities were included as controls. Cranial multilayer spiral CTs (MSCTs) were performed in both groups, and multiplanar reconstruction (MPR) was used as a postprocessing method to measure data related to the posterior cranial fossa in both groups. Results: Compared with the control group, the anteroposterior diameter (labeled AB) and the height (labeled BE) of the bony posterior cranial fossa, the anteroposterior diameter of the foramen magnum (labeled BC), the length of the clivus (labeled AB), and the length of the posterior occipital (labeled CD) in the HFS group were all reduced, and the differences were statistically significant. BE is positively correlated with AB and CD, with a stronger correlation observed between BE and AB (r = 0.487, p < 0.01). AB is negatively correlated with AD (r = -0.473, p < 0.01). The remaining correlations between the data were not statistically significant. There was no overlap in the 95% confidence interval for any of the measurements between the hemifacial spasm group and the control group. Conclusion: There is a correlation between the posterior cranial fossa and hemifacial spasm.

Direct anterior compared to posterior approach for hip hemiarthroplasty following femoral neck fractures.

The differences in complication rates between the direct anterior and posterior approaches for hemiarthroplasty in elderly patients with femoral neck fractures are not yet fully understood. Dislocation, a severe complication associated with increased mortality and often requiring additional surgery, may occur less frequently with the direct anterior approach compared to the posterior approach. Careful consideration of patient demographics is essential when planning the surgical approach. Future research in this area should focus on robust randomized controlled trials involving elderly patients recovering from femoral neck fractures.

Intraoperative and Postoperative Ultrasonographic Spinal Cord Evaluation of Cervical Double-Door Laminoplasty.

BACKGROUND: Ultrasonography is a useful tool for the localization, morphology, and characterization of lesions and is increasingly being applied to spinal cord evaluation in cervical spine diseases. However, in conventional cervical laminoplasty, detailed evaluation is difficult because of ultrasound attenuation. Therefore, the purpose of this study was to perform a cervical laminoplasty using a modified surgical technique and evaluate the spinal cord. METHODS: The spinal cord was evaluated intraoperatively and one week postoperatively in 11 patients with cervical compressive myelopathy. Double-door laminoplasty was selected as the surgical method, and the shape and placement of the bone graft between the expanded laminas were devised to reduce ultrasonic attenuation, such that there was a large space in which the dura mater was visible. RESULTS: Intraoperative and postoperative spinal cord decompression, claudication, and pulsation were confirmed in all cases. A more precise diagnosis was possible using ultrasound attenuation using the grafted bone between the laminas as an indicator. CONCLUSION: Intraoperative and postoperative spinal cord decompression status and wave patterns of modified cervical double-door laminoplasty can be evaluated using ultrasonography. Ultrasound-based evaluations of the spinal cord may provide new insights.

Tacrolimus-induced posterior reversible encephalopathy syndrome following liver transplantation.

In this editorial, we talk about a compelling case focusing on posterior reversible encephalopathy syndrome (PRES) as a complication in patients undergoing liver transplantation and treated with Tacrolimus. Tacrolimus (FK 506), derived from Streptomyces tsukubaensis, is a potent immunosuppressive macrolide. It inhibits T-cell transcription by binding to FK-binding protein, and is able to amplify glucocorticoid and progesterone effects. Tacrolimus effectively prevents allograft rejection in transplant patients but has adverse effects such as Tacrolimus-related PRES. PRES presents with various neurological symptoms alongside elevated blood pressure, and is primarily characterized by vasogenic edema on neuroimaging. While computed tomography detects initial lesions, magnetic resonance imaging, especially the Fluid-Attenuated Inversion Recovery sequence, is superior for diagnosing cortical and subcortical edema. Our discussion centers on the incidence of PRES in solid organ transplant recipients, which ranges between 0.5 to 5 +ACU-, with varying presentations, from seizures to visual disturbances. The case of a 66-year-old male status post liver transplantation highlights the diagnostic and management challenges associated with Tacrolimus-related PRES. Radiographically evident in the parietal and occipital lobes, PRES underlines the need for heightened vigilance among healthcare providers. This editorial emphasizes the importance of early recognition, accurate diagnosis, and effective management of PRES to optimize outcomes in liver transplant patients. The case further explores the balance between the efficacy of immunosuppression with Tacrolimus and its potential neurological risks, underlining the necessity for careful monitoring and intervention strategies in this patient population.

Assessment of average femoral component rotation for balancing functionally aligned total knee replacement in varus deformity: Robotic image guidance study.

Introduction and purpose: Ensuring proper femoral component alignment post-Total Knee Arthroplasty (TKA) is crucial for normal patellofemoral (PF) kinematics. However, the customary 3° external rotation relative to the Posterior Condylar Axis (PC Axis) may not universally apply, and the expected final femoral component rotation remains unclear in functionally aligned knees. This study examines the relation between the Transepicondylar Axis (TEA) and PC axis, known as Posterior Condylar Angle (PCA) in Indian patients along with factors influencing PCA, and the feasibility of reproducing patient-specific PCA using image-guided Cuvis joint robot. Methods: Forty patients (52 Knees) with primary osteoarthritis and varus deformity were prospectively evaluated. Native PCA was determined using CT-based J planner. Pre-operative patellar shape, PF tilt, PF shift, final femoral component rotation (representing post-operative PCA), final patellar tracking, and post-operative functional and radiological assessment at 3 months were recorded. Results: Study participants averaged 64.3 years of age, with a female-to-male ratio of 23 to 17. Varus deformities varied, with IA2 being most prevalent, and sagittal plane deformities included fixed flexion (34.6 %) and hyperextension (44.2 %). The average PCA was 1.9° (range: 0°-7.3°), with most knees (41 out of 52) below 3°. The majority had Wiberg type 1 patellae, with pre-operative patellar tilt averaging 5.63°, reducing post-operatively to 4.43°. Most patients (37 out of 40) achieved excellent Knee Society functional scores at the 3-month mark. Complications included one case of delayed wound healing and one femoral array pin breakage. Notably, our study revealed a significant deviation in PCA from the commonly reported 3° in Western literature, underscoring the need for region-specific considerations in TKA planning. Conclusion: PCA of our population is statistically different from customary 3° followed with jig system. Image guided Robotics helps to identify patients specific PCA and reproducing the same was more commonly possible in patients with reducible Varus deformity.

A digital technique for occlusal design of a posterior full crown based on physiological tooth displacement and occlusion of adjacent teeth.

This article presents a digital technique to construct a virtual occlusion in the maximal intercuspal position (MIP), considering physiological tooth displacement and reducing intermesh penetrations between occlusal surfaces, in order to design more precise and accurate occlusal contacts of a posterior full crown.

The tooth survival of non-surgical root-filled posterior teeth and the associated prognostic tooth-related factors: A systematic review and meta-analysis.

BACKGROUND: Analysis of the survival of root-filled posterior teeth and the associated prognostic tooth-related factors will enable clinicians to predict the outcome of root canal treatment. OBJECTIVES: To investigate (i) the survival of root-filled posterior teeth and (ii) the tooth-related factors that may affect their survival. METHODS: Randomized controlled trials, comparative studies and observational studies assessing survival rates of root-filled posterior teeth with a minimum 4-year follow-up period were identified through an electronic search of the following databases up to January 2023: The Cochrane Central Register of Controlled Trials, Medline via PubMed, the Cochrane Database of Systematic Reviews, Embase, Web of Science and NIHR centre for reviews and dissemination. Two reviewers (SP and ML) independently selected the final studies based on pre-defined inclusion criteria. The Newcastle Ottawa Scale and the Cochrane Risk of Bias Tool for Randomized Trials were used to assess the risk of bias. Pooled weighted survival rates were analysed using a random effects meta-analysis model using DerSimonean and Laird methods. Descriptive analysis of studies describing any prognostic tooth-related factors was conducted. RESULTS: Of the 72 studies identified, data from 20 studies were included in the survival meta-analysis, and data from 13 of these studies were included in the descriptive analysis of tooth-related factors; 12 studies were retrospective, 7 were prospective, and one was a randomized control trial. The pooled survival rates at 4-7 years and 8-20 years of root-filled posterior teeth regardless of tooth type was 91% (95% CI, 0.85; 0.95) and 87% (95% CI, 0.77; 0.93), respectively. The prognostic tooth-related factors mentioned in the included studies were (i) remaining coronal tooth structure, (ii) ferrule, (iii) crown-to-root ratio (iv) tooth type and location (v) periodontal disease (vi) proximal contacts and (vii) cracks. CONCLUSIONS: The meta-analysis suggests that root canal treatment has a high medium to long term survival outcome. The narrative summary identified 7 factors that affect tooth survival. However, there is a paucity of evidence, and more research is needed in this area. REGISTRATION: PROSPERO Registration: CRD42021227213.

Research on the mechanism of leader-follower product sales competition based on market access restrictions and forward contract considerations.

Market access restrictions have been the focus of attention for various market players, but there are fewer studies on the competitive mechanism of market access restrictions on firms' product sales. This paper investigates the competitive mechanism of leader-follower product sales based on market access restrictions and forward contracts. First, the mechanism of leader-follower sales decisions based on market access restrictions and forward contracts is clarified. Second, it models the forward default risk suffered by followers and the profit rate of leader-follower based on market access restrictions and forward considerations by Bayes' posterior probability method. Moreover, it severely explores the impact mechanisms of the degree of market access restrictions on leaders and followers when followers do not adopt and adopt forwards and makes a simulation analysis. The results show that: (i) When followers do not employ forward contracts, the less restrictive degree of market access increases the supply of leaders, and leaders' competition for product sales further leads to a decrease in the provision of followers. (ii) When followers use forwards, leaders' and followers' expected discounted profit rates decrease with the total supply of products in the market increases. (iii) If the degree of market access restrictions is low, the followers suffer an increased forward default risk, resulting in their rate of revenue decrease. The findings of this paper have some practical significance and policy implications for the regulator to adjust the degree of market access restriction in each restricted access area, to establish a reasonable and efficient competitive environment for product sales, as well as for firms to choose the optimal way of competing for product sales.

Effect of Residual Pain After Posterior Fusion Surgery for Lumbar Degenerative Disorders on Health-Related Quality of Life: A Two-Year Follow-Up Using Patient-Reported Outcome Measures.

STUDY DESIGN: This is a prospective cohort study. PURPOSE: The present study aimed to investigate the effects of residual pain after fusion surgery for lumbar degenerative diseases on quality of life (QOL). OVERVIEW OF LITERATURE: Residual symptoms after spinal surgery often restrict patients' activities of daily living and reduce their QOL. However, few studies have comprehensively addressed physical, psychological, and social factors. METHODS: The study population included a cohort of 208 patients (mean age: 67.9 years) who had undergone posterior interbody fusion for lumbar degenerative disease between 2012 and 2019. We asked the patients to complete the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and Short Form Health Survey (SF-36) preoperatively, as well as at six, 12, and 24 months postoperatively. The presence of residual postoperative pain (RPP) was determined using the low back pain score of the JOABPEQ at six months postoperatively, and patients with an improvement of < 20 points compared to preoperative assessment were classified as RPP+ based on a previous study. RESULTS: In all patients, there was a notable postoperative improvement in all JOABPEQ and SF-36 domains compared to preoperative scores. The RPP+ group comprised 60 patients (69.6 years), while the RPP- group comprised 148 patients (67.2 years). In the RPP+ group, the lumbar function in the JOABPEQ and general health in the SF-36 showed limited postoperative enhancement. The pace of improvement in the role-emotional, role-physical, social functioning, vitality, and mental health scores was slower in the RPP+ group compared to the RPP- group. CONCLUSIONS: In the current study, we found that the presence of residual pain at six months postoperatively affected QOL improvement up to 24 months after surgery. Lingering postoperative pain substantially impacted functional incapacity, social engagement, and psychological well-being. Notably, the lumbar function in the JOABPEQ and general health in the SF-36 showed distinct progression patterns in the RPP+ group.