Dual-Mobility Acetabular Components in Primary Total Hip Arthroplasty Do Not Increase the Risk of Complication Compared to Conventional Articulations: A Matched Cohort Comparative Analysis.

Background: A recent National Joint Registry report suggests a higher local complication risk for dual-mobility (DM) total hip arthroplasty (THA) compared to conventional articulation THA. This report may be subject to data heterogeneity with multiple confounders. Controlling for these factors by matching demographic characteristics may give different results. We aim to compare 2-year local complication rates between matched DM and conventional THAs in primary hip osteoarthritis. Methods: Data were collected for consecutive primary THAs undertaken via a posterior approach. The conventional articulation and DM cohorts were matched 3:1 for age, gender, American Society of Anesthesiology grade, body mass index, and operative time using a propensity score and nearest neighbor matching method. Outcome measures were 2-year local complication rates, reoperation rates, systemic complication rates, and mortality rates. Demographic and outcome data were compared, and cumulative survival rates (%) were assessed using Kaplan-Meier methodology with a 2-year local complication as the endpoint. Statistical significance was set at P < .05. Results: Four hundred twelve THAs were included: 309 conventional and 103 DM articulations. There were no statistically significant differences between DM and conventional articulation THAs for local complications (7 [6.8%] vs 23 [7.4%], P = .820), reoperations (3 [2.9%] vs 4 [1.3%], P = .374), systemic complications (3 [2.9%] vs 4 [1.3%], P = .374), or 90-day mortality (1 [1%] vs 2 [0.6%], P = 1.000). Kaplan-Meier survival analysis demonstrated similar 2-year survival rates for conventional THAs compared to DM THAs (93.3% [standard error, 0.014] vs 91.9% [standard error, 0.031], P = .906). Conclusions: This matched study shows that there is no difference in local complication rates between DM and conventional THA articulations.

Risk factors for periprosthetic femoral fracture risk around a cemented polished taper-slip stem using an osteoporotic composite bone model.

This biomechanical study aimed to determine if variations in stem material, stem geometry, stem offset and cement viscosity affect mechanical resistance to postoperative periprosthetic fracture (PFF) after hip arthroplasty with a commonly used cemented polished taper-slip (PTS) stem (CPT, Zimmer Biomet) in a novel osteoporotic composite femoral bone model. Thirty-six osteoporotic composite femoral models were tested using a standardised in-vitro loading technique to simulate a typical PFF. Outcome measures were torque to failure (N), fracture energy (N/m2) and rotation to failure (°). Comparisons were made by stem material (cobalt chrome vs stainless steel), stem geometry (CPT stem vs Exeter stem), stem offset (standard offset vs extra extended offset) and cement viscosity (high viscosity vs low viscosity). Statistical comparisons were carried out with significance set at p < 0.05. All tested samples produced clinically representative fracture patterns with varying degrees of bone and cement comminution. There was no statistically significant difference in torque to failure, fracture energy or rotation to failure between any of the compared variables (all p > 0.05). This is the first biomechanical study on mechanical resistance to PFF using osteoporotic composite bone models. For the CPT stem, it confirms that stem material, stem offset, stem geometry and cement viscosity do not affect mechanical resistance to PFF in an osteoporotic bone model.

Cemented femoral stem design and postoperative periprosthetic fracture risk following total hip arthroplasty.

Polished taper-slip (PTS) cemented stems have an excellent clinical track record and are the most common stem type used in primary total hip arthroplasty (THA) in the UK. Due to low rates of aseptic loosening, they have largely replaced more traditional composite beam (CB) cemented stems. However, there is now emerging evidence from multiple joint registries that PTS stems are associated with higher rates of postoperative periprosthetic femoral fracture (PFF) compared to their CB stem counterparts. The risk of both intraoperative and postoperative PFF remains greater with uncemented stems compared to either of these cemented stem subtypes. PFF continues to be a devastating complication following primary THA and is associated with high complication and mortality rates. Recent efforts have focused on identifying implant-related risk factors for PFF in order to guide preventative strategies, and therefore the purpose of this article is to present the current evidence on the effect of cemented femoral stem design on the risk of PFF.

"Wearable Sensors to Guide Remote Rehabilitation Following Knee Arthroplasty Surgery".

Background: Total knee arthroplasty requires effective rehabilitation to achieve optimal results, but institutions often rely on unsupervised home exercises due to cost constraints. Wearable sensors have become increasingly popular as a potential method of monitoring patients remotely to ensure efficacy and compliance. This review assesses the current evidence for their use in remotely monitored rehabilitation following knee arthroplasty. Methods: A systematic review of the literature from 1st January 2000 to 17th February 2022 was undertaken. Devices were categorised as joint-specific or physical activity sensors. Studies were classified as those providing remotely supervised rehabilitation as an additional or as an alternative intervention. Results: Remotely supervised rehabilitation using wearable sensors demonstrated similar outcomes when provided as an alternative to standard care in most studies. One group found improved outcomes for knee-specific sensors compared with standard care. There were improved physical activity and healthcare resource use outcomes described in the literature where sensors were used in addition to standard care. Discussion: This review found evidence for the use of wearable sensors in remotely supervised rehabilitation following knee arthroplasty surgery. This included methodological heterogeneity, differing definitions of standard care, and variable follow-up periods. Robust randomised control trial data with a longer follow-up period are needed.

Which Unified Classification System type B periprosthetic fractures around cemented polished tapered stems should not be fixed?

The Unified Classification System (UCS), or Vancouver system, is a validated and widely used classification system to guide the management of periprosthetic femoral fractures. It suggests that well-fixed stems (type B1) can be treated with fixation but that loose stems (types B2 and B3) should be revised. Determining whether a stem is loose can be difficult and some authors have questioned how to apply this classification system to polished taper slip stems which are, by definition, loose within their cement mantle. Recent evidence has challenged the common perception that revision surgery is preferable to fixation surgery for UCS-B periprosthetic fractures around cemented polished taper slip stems. Indications for fixation include an anatomically reducible fracture and cement mantle, a well-fixed femoral bone-cement interface, and a well-functioning acetabular component. However, not all type B fractures can or should be managed with fixation due to the risk of early failure. This annotation details specific fracture patterns that should not be managed with fixation alone.

A multicentre comparative analysis of fixation versus revision surgery for periprosthetic femoral fractures following total hip arthroplasty with a cemented polished taper-slip femoral component.

AIMS: The aim of this study was to compare open reduction and internal fixation (ORIF) with revision surgery for the surgical management of Unified Classification System (UCS) type B periprosthetic femoral fractures around cemented polished taper-slip femoral components following primary total hip arthroplasty (THA). METHODS: Data were collected for patients admitted to five UK centres. The primary outcome measure was the two-year reoperation rate. Secondary outcomes were time to surgery, transfusion requirements, critical care requirements, length of stay, two-year local complication rates, six-month systemic complication rates, and mortality rates. Comparisons were made by the form of treatment (ORIF vs revision) and UCS type (B1 vs B2/B3). Kaplan-Meier survival analysis was performed with two-year reoperation for any reason as the endpoint. RESULTS: A total of 317 periprosthetic fractures (in 317 patients) with a median follow-up of 3.6 years (interquartile range (IQR) 2.0 to 5.4) were included. The fractures were type B1 in 133 (42.0%), B2 in 170 (53.6%), and B3 in 14 patients (4.4%). ORIF was performed in 167 (52.7%) and revision in 150 patients (47.3%). The two-year reoperation rate (15.3% vs 7.2%; p = 0.021), time to surgery (4.0 days (IQR 2.0 to 7.0) vs 2.0 days (IQR 1.0 to 4.0); p < 0.001), transfusion requirements (55 patients (36.7%) vs 42 patients (25.1%); p = 0.026), critical care requirements (36 patients (24.0%) vs seven patients (4.2%); p < 0.001) and two-year local complication rates (26.7% vs 9.0%; p < 0.001) were significantly higher in the revision group. The two-year rate of survival was significantly higher for ORIF (91.9% (standard error (SE) 0.023%) vs 83.9% (SE 0.031%); p = 0.032) compared with revision. For B1 fractures, the two-year reoperation rate was significantly higher for revision compared with ORIF (29.4% vs 6.0%; p = 0.002) but this was similar for B2 and B3 fractures (9.8% vs 13.5%; p = 0.341). The most common indication for reoperation after revision was dislocation (12 patients; 8.0%). CONCLUSION: Revision surgery has higher reoperation rates, longer surgical waiting times, higher transfusion requirements, and higher critical care requirements than ORIF in the management of periprosthetic fractures around polished taper-slip femoral components after THA. ORIF is a safe option providing anatomical reconstruction is achievable.Cite this article: Bone Joint J 2023;105-B(2):124-134.

The American Society of Pain and Neuroscience (ASPN) Evidence-Based Clinical Guideline of Interventional Treatments for Low Back Pain.

Introduction: Painful lumbar spinal disorders represent a leading cause of disability in the US and worldwide. Interventional treatments for lumbar disorders are an effective treatment for the pain and disability from low back pain. Although many established and emerging interventional procedures are currently available, there exists a need for a defined guideline for their appropriateness, effectiveness, and safety. Objective: The ASPN Back Guideline was developed to provide clinicians the most comprehensive review of interventional treatments for lower back disorders. Clinicians should utilize the ASPN Back Guideline to evaluate the quality of the literature, safety, and efficacy of interventional treatments for lower back disorders. Methods: The American Society of Pain and Neuroscience (ASPN) identified an educational need for a comprehensive clinical guideline to provide evidence-based recommendations. Experts from the fields of Anesthesiology, Physiatry, Neurology, Neurosurgery, Radiology, and Pain Psychology developed the ASPN Back Guideline. The world literature in English was searched using Medline, EMBASE, Cochrane CENTRAL, BioMed Central, Web of Science, Google Scholar, PubMed, Current Contents Connect, Scopus, and meeting abstracts to identify and compile the evidence (per section) for back-related pain. Search words were selected based upon the section represented. Identified peer-reviewed literature was critiqued using United States Preventive Services Task Force (USPSTF) criteria and consensus points are presented. Results: After a comprehensive review and analysis of the available evidence, the ASPN Back Guideline group was able to rate the literature and provide therapy grades to each of the most commonly available interventional treatments for low back pain. Conclusion: The ASPN Back Guideline represents the first comprehensive analysis and grading of the existing and emerging interventional treatments available for low back pain. This will be a living document which will be periodically updated to the current standard of care based on the available evidence within peer-reviewed literature.

Erenumab for episodic migraine.

In this review, the authors provide an overview of erenumab, a monoclonal antibody used for the preventative treatment of episodic migraine by targeting the CGRP pathway. Randomized controlled trials have shown that erenumab is associated with a statistically significant decrease in monthly migraine days in patients with episodic migraine at monthly doses of 70 or 140 mg when given for a period of 9-12 weeks. Post hoc analyses have also shown long-term maintenance of efficacy. Clinical trials have found erenumab at doses of both 70 and 140 mg to have a favorable safety profile. Erenumab faces significant limitations because of its high financial cost. Additional long-term real-world data are needed to understand the role of erenumab in the treatment of migraine.

In this review, the authors give an overview of erenumab, an injectable medication used to prevent migraine headaches. Erenumab has been proven to be significantly effective in patients with episodic migraines when used at doses of 70 or 140 mg. Furthermore, studies have shown sustained benefit starting as early as the first week of treatment as well as improvement in patients' quality of life. Erenumab has been found to be as safe as placebo in some studies, but there have been some reports of a link to high blood pressure and constipation. However, because of its high cost, patients still face significant barriers to access to erenumab. Additional long-term real-world data are needed to understand the current role of erenumab in the treatment of migraine.

Steroid in Chronic Subdural Hematoma: An Updated Systematic Review and Meta-Analysis Post DEX-CSDH Trial.

BACKGROUND: Chronic subdural hematoma (CSDH) is a neurologic condition characterized as a hematoma in the subdural space with a period >3 weeks that primarily affects the elderly. Glucocorticoid, especially dexamethasone, either alone or combined with surgery, has been used to manage CSDH. We aimed to perform an updated systematic review and meta-analysis of the literature regarding the role of steroids in CSDH. METHODS: We searched the electronic databases PubMed, PubMed Central, Scopus, and Embase for relevant articles until December 2020. Study characteristics, quality, and end points were extracted, and analysis was performed by RevMan 5.4. RESULTS: The odds for subdural hematoma recurrence were decreased by 61% in the steroid group (odds ratio [OR], 0.39; confidence interval [CI], 0.19-0.79) compared with the control group. There was no significant difference in mortality during the study period (OR, 0.66; CI, 0.20-2.18), modified Rankin Scale score 0-3 (OR, 0.87; CI, 0.31-2.40), and modified Rankin Scale score 4-6 (OR, 1.15; CI, 0.42-3.18) between the 2 groups. However, pooling data from 3 studies showed 2.7 times higher odds of occurring adverse effects in steroid groups using the fixed-effect model (OR, 2.70; CI, 1.71-4.28). The treatment success was similar between the steroid and control groups (OR, 2.39; CI, 0.94-6.04). CONCLUSIONS: Treatment with steroids was associated with a lesser recurrence of CSDH. However, there was no benefit of steroid treatment in CSDH compared with nonsteroid treatment in terms of mortality and treatment success and some but significantly increased risk of adverse events.

A systematic review of full endoscopic versus micro-endoscopic or open discectomy for lumbar disc herniation.

Aim: Endoscopic discectomies provide several advantages over other techniques such as traditional open lumbar discectomy (OLD) including possibly decreased complications, shorter hospital stay and an earlier return to work. Methods: An electronic database search including MEDLINE/PubMed, EMBASE, Scopus, Cochrane Database of Systematic Reviews and Cochrane Controlled trials (CENTRAL) were reviewed for randomized controlled trials (RCTs) only. Results: A total of nine RCTs met inclusion criteria. Three showed benefit of endoscopic discectomy over the comparator with regards to pain relief, with the remaining six studies showing no difference in pain relief or function. Conclusion: Based on review of the nine included studies, we can conclude that endoscopic discectomy is as effective as other surgical techniques, and has additional benefits of lower complication rate and superior perioperative parameters.

Lay abstract This systematic review investigates the use of a common surgical procedure, endoscopic discectomy, for the surgical treatment of lumbar disc herniation. It is a type of minimally invasive spine surgery (MISS) procedure, which has been shown to be not only effective in outcomes, but also optimal for peri-operative parameters, such as post-operative hospital stay, time duration of surgery and blood loss during the procedure. We utilized five search databases to collect data on only randomized controlled studies that investigated endoscopic discectomy compared with another surgical technique. Our results include nine randomized controlled trials, three of which showed improvement in pain scores for endoscopic discectomies. Consequently, in combination with the optimal peri-operative measures, it is concluded that endoscopic discectomy is a reasonable procedure to treat lumbar disc herniation surgically.

Periprosthetic femoral fracture type and location are influenced by the presence of an ipsilateral knee arthroplasty implant: A case-control study of 84 interprosthetic femoral fractures.

BACKGROUND: This multicentre case-control study compares Vancouver Classification System (VCS) grade and Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) fracture type in interprosthetic femoral fractures (IPFFs) between primary total hip arthroplasty (THA) and ipsilateral total knee arthroplasty (TKA) to periprosthetic femoral fracture (PFF) without ipsilateral TKA. METHODS: Data were collected following institutional approval. Eighty-four IPFFs were assessed for VCS grade and AO/OTA type. Each IPFF case (84) was matched to five PFF controls (360) by age, gender and stem fixation philosophy (SMD<0.1). VCS grade and AO/OTA type were compared between the IPFF and PFF groups using weighted proportions and medians. RESULTS: Median (IQR) age of IPFF patients was 81.75 (76.57-85.33) years and 61 (72.6%) were female. The commonest VCS grade was B1 (34, 40.5%). The commonest AO/OTA type was spiral (51.8% of VCS B fractures; 50.0% of VCS C fractures). A greater proportion of fractures occurred distal to the stem in IPFF patients versus PFF patients (33.3% versus 18.2%, p = 0.003). VCS grade was significantly different between groups (p = 0.015). For VCS C fractures, twice as many AO/OTA transverse and wedge fractures occurred in the IPFF group compared to the PFF group (25.0% versus 12.6% and 7.1% versus 3.3%, respectively) although the overall difference was not statistically significant (p = 0.407). CONCLUSION: The presence of an ipsilateral TKA affects the location of PFF with more fractures occurring distal to the stem. A greater proportion of bending type fractures occurred when an ipsilateral TKA was present. These unstable fractures often require more complex surgery.

Reliability and validity of the Unified Classification System for postoperative periprosthetic femoral fractures around cemented polished taper-slip stems.

AIMS: This aim of this study was to assess the reliability and validity of the Unified Classification System (UCS) for postoperative periprosthetic femoral fractures (PFFs) around cemented polished taper-slip (PTS) stems. METHODS: Radiographs of 71 patients with a PFF admitted consecutively at two centres between 25 February 2012 and 19 May 2020 were collated by an independent investigator. Six observers (three hip consultants and three trainees) were familiarized with the UCS. Each PFF was classified on two separate occasions, with a mean time between assessments of 22.7 days (16 to 29). Interobserver reliability for more than two observers was assessed using percentage agreement and Fleiss' kappa statistic. Intraobserver reliability between two observers was calculated with Cohen kappa statistic. Validity was tested on surgically managed UCS type B PFFs where stem stability was documented in operation notes (n = 50). Validity was assessed using percentage agreement and Cohen kappa statistic between radiological assessment and intraoperative findings. Kappa statistics were interpreted using Landis and Koch criteria. All six observers were blinded to operation notes and postoperative radiographs. RESULTS: Interobserver reliability percentage agreement was 58.5% and the overall kappa value was 0.442 (moderate agreement). Lowest kappa values were seen for type B fractures (0.095 to 0.360). The mean intraobserver reliability kappa value was 0.672 (0.447 to 0.867), indicating substantial agreement. Validity percentage agreement was 65.7% and the mean kappa value was 0.300 (0.160 to 0.4400) indicating only fair agreement. CONCLUSION: This study demonstrates that the UCS is unsatisfactory for the classification of PFFs around PTS stems, and that it has considerably lower reliability and validity than previously described for other stem types. Radiological PTS stem loosening in the presence of PFF is poorly defined and formal intraoperative testing of stem stability is recommended. Cite this article: Bone Joint J 2021;103-B(8):1339-1344.

Risk factors influencing fracture characteristics in postoperative periprosthetic femoral fractures around cemented stems in total hip arthroplasty : a multicentre observational cohort study on 584 fractures.

AIMS: This study evaluates risk factors influencing fracture characteristics for postoperative periprosthetic femoral fractures (PFFs) around cemented stems in total hip arthroplasty. METHODS: Data were collected for PFF patients admitted to eight UK centres between 25 May 2006 and 1 March 2020. Radiographs were assessed for Unified Classification System (UCS) grade and AO/OTA type. Statistical comparisons investigated relationships by age, gender, and stem fixation philosophy (polished taper-slip (PTS) vs composite beam (CB)). The effect of multiple variables was estimated using multinomial logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs). Surgical treatment (revision vs fixation) was compared by UCS grade and AO/OTA type. RESULTS: A total of 584 cases were included. Median age was 79.1 years (interquartile range 72.0 to 86.0), 312 (53.6%) patients were female, and 495 (85.1%) stems were PTS. The commonest UCS grade was type B1 (278, 47.6%). The most common AO/OTA type was spiral (352, 60.3%). Metaphyseal split fractures occurred only with PTS stems with an incidence of 10.1%. Male sex was associated with a five-fold reduction in odds of a type C fracture (OR 0.22 (95% CI 0.12 to 0.41); p < 0.001) compared to a type B fracture. CB stems were associated with significantly increased odds of transverse fracture (OR 9.51 (95% CI 3.72 to 24.34); p < 0.001) and wedge fracture (OR 3.72 (95% CI 1.16 to 11.95); p = 0.027) compared to PTS stems. Both UCS grade and AO/OTA type differed significantly (p < 0.001 and p = 0.001, respectively) between the revision and fixation groups but a similar proportion of B1 fractures underwent revision compared to fixation (45.3% vs 50.6%). CONCLUSION: The commonest fracture types are B1 and spiral fractures. PTS stems are exclusively associated with metaphyseal split fractures, but their incidence is low. Males have lower odds of UCS grade C fractures compared to females. CB stems have higher odds of bending type fractures (transverse and wedge) compared to PTS stems. There is considerable variation in practice when treating B1 fractures around cemented stems. Cite this article: Bone Jt Open 2021;2(7):466-475.

Treatment of knee osteoarthritic pain with platelet-rich plasma: a systematic review of clinical studies.

Introduction: Knee osteoarthritis is a degenerative joint disease that is secondary to degradation of articular cartilage, reformation of subchondral bone through degradation and proliferation as well as presence of synovitis. Materials & methods: This systematic review was conducted and reported as per Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Results: A total of 30 of the 48 comparators showed statistically significant superiority with platelet-rich plasma (PRP) compared with a control, while the other 16 comparators showed no significant difference between PRP and the comparator. Conclusion: We can only recommend PRP for patients with early-stage osteoarthritis (I or II) and who are aged below 65, based on our findings. Based on the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) recommendations, while studies reviewed were randomized controlled studies, and therefore, high grade, due to variance in imprecision, risk of bias and inconsistency among the 37 studies, it would be reasonable to rate this paper as subjectively moderate.

Postoperative periprosthetic femoral fracture around total hip replacements: current concepts and clinical outcomes.

The rising incidence of postoperative periprosthetic femoral fracture (PFF) presents a significant clinical and economic burden.A detailed understanding of risk factors is required in order to guide preventative strategies.Different femoral stems have unique characteristics and management strategies must be tailored appropriately.Consensus regarding treatment of PFFs around well-fixed stems is lacking, but revision surgery may provide more predictable outcomes for unstable fracture patterns and fractures around polished taper-slip stems.Future research should focus on implant-related risk factors, treatment of concurrent metabolic bone disease and the use of large endoprostheses. Cite this article: EFORT Open Rev 2020;5:558-567. DOI: 10.1302/2058-5241.5.200003.

Intraosseous Anesthesia Using Dynamic Navigation Technology.

INTRODUCTION: This study presents a novel method to deliver intraosseous anesthesia using dynamic navigation technology. The study aimed to evaluate its safety and 3-dimensional (3D) accuracy in comparison to traditional freehand injection of intraosseous anesthesia. METHODS: Six identical sets of 3D-printed surgical jaw models (TrueJaw; DELendo, Santa Barbara, CA) comprising simulated alveolar and dental anatomy with 54 interradicular sites were used in this study. The injection sites were equally distributed based on the range of the inter-radicular distance (ie, 1.5-2.5 mm, 2.5-3.5 mm, and 3.5-4.5 mm). A board-certified endodontist randomly completed intraosseous drilling at inter-radicular sites of varying distance using freehand technique and the Navident dynamic navigation system (ClaroNav, Toronto, Ontario, Canada) with the X-Tip system (Dentsply Sirona, York, PA). The rate of root perforation associated with inter-radicular distance was compared between the 2 groups using the Fisher exact test. Two-dimensional (2D) and 3D horizontal, vertical, and angulation discrepancies between the planned and dynamically navigated guide sleeves were digitally measured using superimposed cone-beam computed tomographic scans. Analysis of variance models were used to determine if the interdental distance was associated with the accuracy measures from the dynamic navigation system. The significance level was set at 0.05. RESULTS: The rate of root perforation was significantly higher for the freehand group than the dynamic navigation (22% vs 0%, P < .05). For dynamic navigation, the 2D entry deviation was 0.71 mm (95% confidence interval [CI], 0.56-0.87). The mean 2D horizontal deviation was 0.96 mm (95% CI, 0.79-1.14), and the mean 2D vertical deviation was 0.70 mm (95% CI, 0.55-0.84). The 3D deviation at the tip was on an average 1.23 mm (95% CI, 1.05-1.42). The overall 3D angular deviation was on average 1.36° (95% CI, 1.15-1.56). The inter-radicular distance was not significantly associated with any 2D or 3D discrepancies. CONCLUSIONS: Successful and accurate drilling of dynamically navigated intraosseous delivery occurred in 100% of injection sites irrespective of the inter-radicular distance. It was significantly safer in comparison to freehand intraosseous drilling to prevent injury of the roots of the adjacent teeth in close proximity.

Dynamically Navigated versus Freehand Access Cavity Preparation: A Comparative Study on Substance Loss Using Simulated Calcified Canals.

INTRODUCTION: The aim of this in vitro study was to compare the speed, qualitative precision, and quantitative loss of tooth structure with freehand and dynamically navigated access preparation techniques for root canal location in 3-dimensional-printed teeth with simulated calcified root canals. METHODS: Forty maxillary and mandibular central incisors (tooth #9 and tooth #25) were 3-dimensionally printed to simulate canal calcification. Under simulated clinical conditions, access preparations were randomly performed with contemporary freehand and dynamically navigated techniques. Qualitative precision and quantitative loss of tooth structure were assessed on postoperative cone-beam computed tomographic scans using ITK-SNAP open-source segmentation (http://www.itksnap.org/). The associations between jaw, technique, volume of substance loss, and operating time were determined using analysis of variance models with Tukey-adjusted post hoc pair-wise comparisons. The kappa statistic was used to determine agreement between 2 independent, blinded raters on the qualitative assessment of the drill path. The association between the technique and jaw and qualitative assessment scoring was compared using the Fisher exact test. The significance level was set at .05. RESULTS: Dynamically navigated accesses resulted in significantly less mean substance loss in comparison with the freehand technique (27.2 vs 40.7 mm3, P < .05). Dynamically navigated accesses were also associated with higher optimal precision (drill path centered) to locate calcified canals in comparison with the freehand technique (75% vs 45%, P > .05). Mandibular teeth were associated with a negligible difference in substance loss between the access techniques (19.0 vs 19.1 mm3, P > .05). However, qualitatively the freehand technique was still prone to 30% higher chance of suboptimal precision (drill path tangentially transported) in locating calcified canals. Overall, dynamically navigated accesses were prepared significantly faster than freehand preparations (2.2 vs 7.06 minutes, P < .05). CONCLUSIONS: Within the limitations of this in vitro study, overall dynamically navigated access preparations led to significantly less mean substance loss with optimal and efficient precision in locating simulated anterior calcified root canals in comparison with freehand access preparations.

A Systematic Literature Review of Peripheral Nerve Stimulation Therapies for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of peripheral nerve stimulation (PNS) for pain. DESIGN: Grade the evidence for PNS. METHODS: An international interdisciplinary work group conducted a literature search for PNS. Abstracts were reviewed to select studies for grading. Inclusion/exclusion criteria included prospective randomized controlled trials (RCTs) with meaningful clinical outcomes that were not part of a larger or previously reported group. Excluded studies were retrospective, had less than two months of follow-up, or existed only as abstracts. Full studies were graded by two independent reviewers using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: Peripheral nerve stimulation was studied in 14 RCTs for a variety of painful conditions (headache, shoulder, pelvic, back, extremity, and trunk pain). Moderate to strong evidence supported the use of PNS to treat pain. CONCLUSION: Peripheral nerve stimulation has moderate/strong evidence. Additional prospective trials could further refine appropriate populations and pain diagnoses.

Minimally invasive lumbar decompression: a review of indications, techniques, efficacy and safety.

Lumbar spinal stenosis is a common degenerative spine condition. In properly selected patients, minimally invasive lumbar decompression (mild®) may be an option to improve outcomes. This review provides an in-depth description of the mild procedure and a comprehensive examination of safety and efficacy. Two randomized controlled trials, together with 11 other controlled clinical studies, have established the efficacy of mild, which is a minimally invasive procedure that does not involve implants and has demonstrated excellent efficacy and safety. With an established safety profile equivalent to epidural steroid injections, and efficacy that has been shown to be superior to such injections, mild can reasonably be positioned early in the treatment algorithm for these patients. Based on extensive review of the literature, robust safety and efficacy through 2 years, and in accordance with minimally invasive spine treatment guidelines, mild is recommended as the first intervention after failure of conservative measures for lumbar spinal stenosis patients with neurogenic claudication and ligamentum flavum hypertrophy.