Advanced convolutional neural network modeling for fuel cell system optimization and efficiency in methane, methanol, and diesel reforming.

Fuel cell systems (FCSs) have been widely used for niche applications in the market. Furthermore, the research community has worked on using FCSs for different sectors, such as transportation, stationary power generation, marine and maritime, aerospace, military and defense, telecommunications, and material handling. The reformation of various fuels, such as methanol, methane, and diesel can be utilized to generate hydrogen for FCSs. This study introduces an advanced convolutional neural network (CNN) model designed to accurately forecast hydrogen yield and carbon monoxide volume percentages during the reformation processes of methane, methanol, and diesel. Moreover, the CNN model has been tailored to accurately estimate methane conversion rates in methane reforming processes. The proposed CNN models are created by combining the 3D-CNN and 2D-CNN models. The Keras Tuner approach in Python is employed in this study to find the ideal values for different hyperparameters such as batch size, learning rate, time steps, and optimization method selection. The accuracy of the proposed CNN model is evaluated by using the root mean square error (RMSE), mean absolute percentage error (MAE), mean absolute error (MAE), and R2. The results indicate that the proposed CNN model is better than other artificial intelligence (AI) techniques and standard CNN for performance estimation of reforming processes of methane, diesel, and methanol. The results also show that the suggested CNN model can be used to accurately estimate critical output parameters for reforming various fuels. The proposed method performs better in CO prediction than the support vector machine (SVM), with an R2 of 0.9989 against 0.9827. This novel methodology not only improves performance estimation for reforming processes but also provides a valuable tool for accurately estimating output parameters across various fuel types.

Evaluation of Differences in Patellar Height After Patellar Stabilization Procedures Not Intended to Address Patella Alta: A Multicenter Study.

Background: Recent studies have reported conflicting results as to whether isolated medial patellofemoral ligament reconstruction (MPFLr) leads to decreased patellar height. Purpose: To investigate if patellar stabilization surgery not intended to address patella alta influences patellar height. Study Design: Cohort study; Level of evidence, 3. Methods: A multicenter retrospective chart review was conducted, and patients who underwent MPFLr, medializing tibial tuberosity osteotomy (TTO), and/or trochleoplasty between 2016 and 2020 were included. The Caton-Deschamps index (CDI) was calculated from radiographs obtained preoperatively, 2 weeks postoperatively, and 3 months postoperatively. The preoperative CDI value was compared with the 2-week postoperative and 3-month postoperative values according to stabilization procedure (isolated MPFLr, isolated TTO, MPFLr + TTO, MPFLr + trochleoplasty, and MPFLr + trochleoplasty + TTO) using the paired t test. Analyses of the 1-bundle versus 2-bundle MPFLr technique and the presence of lateral retinacular release or lateral retinacular lengthening were conducted on the isolated MPFLr and combined MPFLr + TTO cohorts. Results: A total of 356 knees were included. Statistically significant pre- to postoperative decreases in CDI were seen in all stabilization procedures analyzed (P≤ .017 for all). Within the isolated MPFLr cohort, this significant decrease was seen at 2 weeks postoperatively with the 2-bundle technique (ΔCDI = -0.09; P < .001) but not with the 1-bundle technique (ΔCDI = -0.01; P = .621). Conclusion: The different surgical techniques analyzed in the current study affected patellar height, even when a distalizing TTO was not performed. The decrease was dependent on surgical technique, with a 2-bundle MPFLr leading to a statistically significant decrease and a 1-bundle MPFLr effecting no change.

The Effect of Aspiration and Corticosteroid Injection After ACL Injury on Postoperative Infection Rate.

BACKGROUND: Injecting bioactive substances into the knee is common in orthopaedic practice, and recently it has been shown to mitigate risk factors for posttraumatic osteoarthritis. Therefore, understanding the influence of these injections on postoperative infection rate is imperative. HYPOTHESIS: Postinjury aspiration and corticosteroid injection (CSI) of the knee before anterior cruciate ligament (ACL) reconstruction (ACLR) would not increase the risk of postoperative infection. STUDY DESIGN: Cohort Study; Level of evidence, 3. METHODS: All patients between the ages of 10 and 65 years who underwent primary bone-patellar tendon-bone ACLR by 1 fellowship-trained sports medicine orthopaedic surgeon between January 1, 2011, and September 8, 2020, at 1 of 2 major academic centers were evaluated for inclusion. A total of 693 patients were included, with 273 patients receiving postinjury and preoperative aspiration and CSI. A postoperative infection was defined as a patient returning to the operating room for an intra-articular washout. The intervals-measured in days-between the CSI and ACLR and between ACLR and the final follow-up were recorded. To further evaluate the infection risk in each cohort (total cohort; aspiration and injection cohort; no aspiration and injection cohort), the upper 95% confidence bound for the infection risk was calculated for each cohort. RESULTS: There were no postoperative infections in the 693 patients included in this study. The upper 95% confidence bounds were 0.4%, 1.1%, and 0.7% for the total cohort, the cohort that underwent aspiration and injection, and the cohort that did not, respectively. The median number of days between the surgical date and that of the aspiration and injection was 34 days, and the mean follow-up for the entire cohort was 337.4 days (95% CI, 307.6-367.3). CONCLUSION: Postinjury and preoperative aspiration and CSI is a safe intervention that can be used before ACLR. Future studies with larger sample sizes, longer patient follow-ups, and multiple surgeons would be helpful to both better understand infection risk and better identify the influence of CSI on preventing posttraumatic osteoarthritis.

Factors Associated With Increased Opioid Prescriptions Following Anterior Cruciate Ligament Reconstruction in Opioid-Naïve Patients.

Purpose: To identify the mean morphine milligram equivalent (MME) opioid prescriptions for opioid-naïve patients undergoing isolated anterior cruciate ligament reconstruction (ACLR) between 4 weeks before surgery and the first 90 days after surgery and to describe opioid prescriptions filled per patient and mean MMEs per year within 90 days following ACLR. Methods: Exclusion criteria were patients having concurrent other cruciate or collateral ligament repair or reconstruction, meniscus procedures (repair and debridement), any cartilage procedure, lower-extremity osteotomy, or knee procedures for fracture, infection, or neoplasms; patients with substance use disorder or chronic pain also were excluded. Opioid use between 4 weeks before surgery and the first 90 days after surgery was recorded. Prescribing physician specialty also was tracked. The correlation of patient factors and prescriber specialty of MME were compared using the Student's t-test. Significance was defined at P < .05. Results: Opioid-naïve patients undergoing isolated ACLR were included. Isolated arthroscopic ACLRs performed between 2010 and Q3 2020 in opioid-naïve patients were identified within the PearlDiver M91 national database. A total of 37,200 patients were identified. Mean MME per patient was 340.9 ± 198.2, with an average MME per day of 59.9. Factors associated with increased opioid use during the 90 days following ACLR were older age (P < .001) and preoperative diagnosis of depression (P < .001). Orthopaedic surgeons were primarily responsible for the number of opioid prescriptions after ACLR (n = 29,326, 73.0%) but 27% (n = 10,797) of prescriptions came from nonorthopaedic surgeon medical providers who prescribed significantly greater MMEs of opioids than orthopaedic surgeons (456.5 vs 339.2, P < .001) per patient. Lastly, decreasing yearly opioid prescriptions per patient (2.4 to 1.6 prescriptions) and the mean MME per patient (428.4 to 257.1) occurred from 2010 to 2020. Conclusions: Older age and preoperative diagnosis of depression are associated with greater opioid doses after ACLR. In addition, the vast majority of opioid prescriptions are written by orthopaedic surgeons on the day of ACLR and decreased considerably by four weeks after surgery. Patients receiving opioid prescriptions by nonorthopaedic surgeon medical providers receive significantly greater doses. Level of Evidence: Level IV, retrospective cohort study.

Incidence of Early Adverse Events After Tibial Tubercle Osteotomy.

Background: Tibial tubercle osteotomy (TTO) is a commonly utilized surgical procedure for the treatment of patellofemoral instability. Although midterm and long-term outcomes are known, perioperative complications have not been consistently reported. Purpose: To identify the incidence and predictors of adverse events in the first 90-day perioperative period after TTO. Study Design: Case series; Level of evidence, 4. Methods: Patients undergoing primary TTO between January 1, 2010, and December 31, 2019, were included. Readmissions in the first 90 days after surgery were collected, and data were collected for the following variables: age, sex, smoking status, body mass index, laterality, preoperative diagnosis, presence of trochlear dysplasia, tourniquet use, TTO procedure, tibial tubercle distalization, trochleoplasty, chondral procedure, number of screws, and use of an epidural catheter. Predictors of readmission for any reason were identified using multivariable logistic regression analysis. Results: A total of 345 TTO procedures were included in the final analysis. The incidence of readmissions for any reason was 20.6% (71/345). The most common reason for readmission was postoperative pain (26/345 [7.5%]), followed by wound complications (19/345 [5.5%]) and epidural catheter-related complications (overall: 16/345 [4.6%]; specific: 16/167 [9.6%]. The incidence of major complications was 2.0% (7/345). The number of patients with each major complication was as follows: 1 for deep vein thrombosis, 2 for pulmonary embolism, 1 for septic arthritis, 1 for tibial tubercle fracture, and 2 for loss of fixation. Female sex and smoking were associated with readmission for pain. Conclusion: The incidence of major complications after TTO was very low (2.0%), but 20.6% of cases required readmission, primarily for an indwelling epidural catheter (3.5%) and postoperative pain (7.5%). Concomitant soft tissue procedures and the number of screws were associated with readmission after TTO. Utilizing individualized postoperative pain management and preoperative discussions about expected pain may help to avoid readmission for pain after TTO.

Examining the Schenck KD I Classification in Patients With Documented Tibiofemoral Knee Dislocations: A Multicenter Retrospective Case Series.

Background: Acute tibiofemoral knee dislocations (KDs) with a single cruciate ligament remaining intact are rare and can be classified as Schenck KD I. The inclusion of multiligament knee injuries (MLKIs) has contributed to a recent surge in Schenck KD I prevalence and has convoluted the original definition of the classification. Purpose: To (1) report on a series of true Schenck KD I injuries with radiologically confirmed tibiofemoral dislocation and (2) introduce suffix modifications to further subclassify these injuries based on the reported cases. Study Design: Case series; Level of evidence, 4. Methods: A retrospective chart review identified all Schenck KD I MLKIs at 2 separate institutions between January 2001 and June 2022. Single-cruciate tears were included if a concomitant complete disruption of a collateral injury was present or injuries to the posterolateral corner, posteromedial corner, or extensor mechanism. All knee radiographs and magnetic resonance imaging scans were retrospectively reviewed by 2 board-certified orthopaedic sports medicine fellowship-trained surgeons. Only documented cases consistent with a complete tibiofemoral dislocation were included. Results: Of the 227 MLKIs, 63 (27.8%) were classified as KD I, and 12 (19.0%) of the 63 KD I injuries had a radiologically confirmed tibiofemoral dislocation. These 12 injuries were subclassified based on the following proposed suffix modifications: KD I-DA (anterior cruciate ligament [ACL] only; n = 3), KD I-DAM (ACL + medial collateral ligament [MCL]; n = 3), KD I-DPM (posterior cruciate ligament [PCL] + MCL; n = 2), KD I-DAL (ACL + lateral collateral ligament [LCL]; n = 1), and KD I-DPL (PCL + LCL; n = 3). Conclusion: The Schenck classification system should only be used to describe dislocations with bicruciate injuries or with single-cruciate injuries that have clinical and/or radiological evidence of tibiofemoral dislocation. Based on the presented cases, the authors recommend the suffix modifications for subclassifying Schenck KD I injuries with the goal of improving communication, surgical management, and the design of future outcome studies.

Opioid Prescription Patterns 90 Days After Arthroscopic Rotator Cuff Repair: A 10-Year National Database Analysis.

Background: Arthroscopic rotator cuff repair (ARCR) is a common procedure that typically requires opioid prescription for postoperative pain management. Purpose: To investigate the current prescription patterns and factors influencing 90-day postoperative opioid prescription trends for opioid-naïve patients who underwent ARCR. Study Design: Case series; Level of evidence, 4. Methods: Opioid-naïve adult patients who underwent ARCR between January 2010 and September 2020 and had a record of opioid prescriptions during the 90-day postoperative period were identified in the PearlDiver Mariner91 national administrative database. Exclusions included patients with prior shoulder procedures, a history of chronic pain, and opioid prescription records dated earlier than 4 weeks before surgery. Covariates included age group, sex, Elixhauser Comorbidity Index, and prescriber specialty (orthopaedic or nonorthopaedic). The primary outcome-90-day postoperative morphine milligram equivalents (MMEs) prescribed per patient-was compared using univariate and multivariate regression analyses, and 90-day postoperative opioid prescription trends over the 10-year study period were analyzed with linear regression. Results: In total, 55,345 ARCR cases were identified. The mean ± SD amount prescribed within the first 90 days was 742.4 ± 256.5 MMEs, and the median was 487.5 MMEs. Multivariate linear regression analysis predicted higher 90-day postoperative MMEs for female patients and younger patients (P < .01 for both). From 2010 to 2020, there was a 66% decrease in mean MME prescribed per patient (▵ = 660.4 MME; P < .01), with a mean reduction of 55.1 MME per patient per year. In 2020, the mean 90-day postoperative amount prescribed was 341.1 MME, which is equivalent to 51 tablets of 5-mg oxycodone (Percocet). Conclusion: Female sex and younger age were predictors of more MME being prescribed after ARCR. While opioid prescriptions following ARCR have substantially decreased over the past decade, the amount prescribed warrants further attention.

Do Patellar Tendon Repairs Have Better Outcomes than Quadriceps Tendon Repairs? A Prospective Cohort Analysis.

Patellar tendon (PT) and quadriceps tendon (QT) ruptures represent significant injuries and warrant surgical intervention in most patients. Outcome data are predominantly retrospective analyses with low sample sizes. There are also minimal data comparing QT and PT repairs and the variables impacting patient outcomes. The level of evidence of the study is level II (prognosis). From the prospective OME cohort, 189 PT or QT repairs were performed between February 2015 and October 2019. Of these, 178 were successfully enrolled (94.2%) with 1-year follow-up on 141 (79.2%). Baseline demographic data included age, sex, race, BMI, years of education, smoking status, and baseline VR-12 MCS score. Surgical and follow-up data included surgeon volume, fixation technique, baseline, and 1-year Knee Injury and Osteoarthritis Outcome Score-Pain (KOOS-Pain), Knee Injury and Osteoarthritis Outcome Score-Physical Function (KOOS-PS), and 1-year Patient Acceptable Symptom State (PASS) scores and complications. Multivariable regression analysis was utilized to identify prognosis and significant risk factors for outcomes-specifically, whether KOOS-Pain or KOOS-PS were different between QT versus PT repairs. There were 59 patients in the PT cohort and 82 patients in QT cohort. Baseline demographic data demonstrated that PT cohort was younger (45.1 vs. 59.5 years, p <0.001), included significantly fewer patients of White race (51.7 vs. 80.0%, p = 0.001), lesser number of years of education (13.9 vs. 15.2 years, p = 0.020), a higher percentage of "high" surgeon volume (72.9% vs. 43.9%, p = 0.001) and 25.4% of PT repairs had supplemental fixation (QT had zero, p <0.001). Multivariable analysis identified gender (female-worse, p = 0.001), years of education (higher-better, p = 0.02), and baseline KOOS-Pain score (higher-better, p <0.001) as the risk factors that significantly predicted KOOS-Pain score. The risk factors that significantly predicted KOOS-PS were gender (female worse, p = 0.033), race (non-White-worse, p <0.001), baseline VR-12 MCS score (higher-better, p <0.001), and baseline KOOS-PS score (higher better, p = 0.029). KOOS-Pain and KOOS-PS scores improved after both QT and PT repairs. Patient reported pain and function at 1 year were similar between PT and QT repairs after adjusting for known risk factors. Multivariable analysis identified female gender and low baseline KOOS scores as predictors for worse outcomes.

Posteromedial tibial plateau bone bruises are associated with medial meniscal ramp lesions in patients with concomitant anterior cruciate ligament ruptures: a systematic review & meta-analysis.

OBJECTIVE: To determine if posteromedial tibial plateau (PMTP) bone bruising on pre-operative MRI is significantly associated with a ramp lesion identified during arthroscopy in patients with concomitant ACL ruptures. METHODS: PubMed, CINAHL, Scopus, Web of Sciences, EMBASE, and Cochrane Library were searched systematically for studies that investigated the association between PMTP bone bruises on preoperative MRI and ramp lesions confirmed during arthroscopy. Eight studies met inclusion criteria. The Methodological Index for Nonrandomized Studies (MINORS) checklist was used to assess quality. A meta-analysis was performed to analyze odds of a ramp lesion after PMTP bone bruising identified on magnetic resonance imaging (MRI). Publication bias was assessed by funnel plot and Egger's linear regression test. RESULTS: There are 2.05 greater odds of medial meniscal ramp lesions in patients with an ACL rupture when PMTP bone bruising is found on preoperative MRI (95% CI, 1.29-3.25; p = 0.002). Heterogeneity of the pooled studies may be substantial (I2 = 65%; p = 0.006). Funnel plot analysis and Egger's linear regression test (p > 0.5) determined no publication bias among the studies included in the meta-analysis. CONCLUSION: Patients with acute ACL injuries and PMTP bone bruising on MRI have 2.05 times greater odds of a concomitant medial meniscal ramp lesion than those without this bone bruise pattern.

Posteromedial Tibial Bone Bruise After Anterior Cruciate Ligament Injury: An MRI Study of Bone Bruise Patterns in 208 Patients.

Background: Bone bruise patterns after anterior cruciate ligament (ACL) rupture may predict the presence of intra-articular pathology and help explain the mechanism of injury. Lateral femoral condyle (LFC) and lateral tibial plateau (LTP) bone bruises are pathognomic to ACL rupture. There is a lack of information regarding medial tibial plateau (MTP) and medial femoral condyle (MFC) bone bruises. Purpose: To summarize the prevalence and location of MTP bone bruises with acute ACL rupture and to determine the predictors of MTP bone bruises. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Inclusion criteria were patients who underwent ACL reconstruction between February 2015 and November 2017, magnetic resonance imaging (MRI) within 90 days of injury, and participation in the database. Exclusion criteria included previous ipsilateral surgery, multiligamentous injuries, and incomplete imaging. Due to the large number of cases remaining (n = 600), 150 patients were selected randomly from each year included in the study, for a total of 300 patients. Two readers independently reviewed injury MRI scans using the Costa-Paz bone bruise grading system. Logistic regression was used to identify factors associated with MTP bone bruises. Results: Included were 208 patients (mean age, 23.8 years; mean body mass index, 25.6). The mechanism of injury was noncontact in 59% of injuries, with over half from soccer, basketball, and football. The median time from injury to MRI scan was 12 days. Of the 208 patients, 98% (203/208) had a bone bruise, 79% (164/208) had an MTP bone bruise, and 83% (172/208) had bruises in both medial and lateral compartments. The most common pattern, representing 46.6% of patients (97/208), was a bruise in all 4 locations (MFC, LFC, MTP, and LTP). Of the 164 MTP bruises, 160 (98%) involved the posterior third of the plateau, and 161 were grade 1. The presence of an MFC bruise was the only independent risk factor for an MTP bruise (odds ratio, 3.71). The resulting nomogram demonstrated MFC bruise, sport, and mechanism of injury were the most important predictors of an MTP bruise. Conclusion: MTP bruise after acute ACL rupture was as prevalent as lateral bruises. The presence of a posterior MTP bruise suggested anterior tibial translation at the time of injury and could portend more medial compartment pathology at the time of injury than previously recognized.

Factors Associated With Pain and Function Before Medial Patellofemoral Ligament Reconstruction.

Background: Medial patellofemoral ligament (MPFL) reconstruction is performed to treat recurrent patellar instability. Measurement of joint pain and function at the time of surgery has been demonstrated to be a predictor of the final outcomes in many surgical procedures. Purpose/Hypothesis: The purpose of this study was to evaluate the relationship between baseline patient characteristics, mental health, and intraoperative findings and patient-reported knee pain and function at the time of MPFL reconstruction. We hypothesized that patient characteristics and associated pathology would be associated with the degree of pain and dysfunction. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Included were skeletally mature patients who underwent unilateral open MPFL reconstruction between 2015 and 2020 at a single institution. Baseline descriptive information was collected, and the following outcome measures were administered preoperatively: the Veterans RAND 12-Item Health Survey Mental Component Score (VR-12 MCS) and the Knee injury and Osteoarthritis Outcome Score (KOOS) Pain, Physical Function Short Form (PS), and Quality of Life (QoL) subscales. Intraoperative findings were collected in a standardized format. Patient characteristics, preoperative variables, intraoperative findings, and VR-12 MCS were used as risk factors, and multivariate analysis was conducted to assess for relationships with the KOOS subscale scores. Results: In total, 201 patients with patella dislocations were included in this analysis. Intraoperatively, 122 patients (60.7%) had either normal cartilage or grade 1 or 2 cartilage injury, 79 patients (39.3%) had grade 3 or 4 cartilage injury, 35 patients (17.4%) had a loose body, and 3 patients (1.49%) had evidence of synovitis. Younger age (P = .012), male sex (P < .001), never having smoked (P = .029), and lower baseline VR-MCS (P < .001) were significantly associated with higher baseline KOOS Pain scores. Older age (P = .035), female sex (P = .003), higher body mass index (P = .005), and lower baseline VR-12 MCS (P < .001) were significantly associated with higher baseline KOOS PS scores. Younger age (P = .003), male sex (P < .001), lower baseline VR-12 MCS (P < .001), and no dysplasia (P = .023) were significantly associated with higher baseline KOOS QoL scores. Conclusion: Patient age, sex, and baseline VR-12 MCS were associated with all 3 baseline KOOS subscale scores, whereas intraoperative findings outside of trochlear dysplasia were not associated with any of the KOOS subscale scores.

Brain stroke classification and segmentation using encoder-decoder based deep convolutional neural networks.

Accurate diagnosis of brain stroke, classification and segmentation of the stroke are extremely important for physicians to focus on specific points of the brain and apply the right treatment to patients. Encoder-decoder deep learning-based methods have been effectively integrated into many artificial intelligence applications. On the other hand, such networks have many disadvantages due to sampling methods, learning methodologies, and efficient operations. In this study, U-Net, one of the encoder-decoder deep learning-based convolutional neural networks (CNNs), has been developed and proposed for the classification and segmentation of brain stroke. A convolutional deep network architecture is proposed with an optimized dimensional U-Net (D-UNet) by blocking and adaptively sequencing the convolution layers and then optimizing the number of activation functions and hyperparameters. The proposed method examines the computed tomography (CT) images from the dataset used to determine whether there is a brain stroke. It can determine if a stroke is caused by ischemia or hemorrhage once it has occurred. Additionally, the proposed method can precisely reveal the region overlaid by the radiologist and segment the existing stroke. The proposed method is compared with other existing CNN-type architectures by performing various experiments on the same real dataset via Python scripts. The results show that the proposed model performs well, with accuracy rates for stroke classification of 98.9% and ischemia and hemorrhage classification of 98.5%, respectively. Moreover, the segmentation of brain strokes using the proposed model yielded an intersection over union (IoU) rate of 95.2%.

Arthroscopic Synovectomy for Tenosynovial Giant Cell Tumor/Pigmented Villonodular Synovitis in the Posterior Knee Using the Posterior Trans-Septal Portal Technique.

Tenosynovial giant cell tumor (T-GCT) and pigmented villonodular synovitis (PVNS) are interchangeable terms for an uncommon benign proliferation of synovial tissue1-6. Although neoplastic and inflammatory origins have been hypothesized, the etiology of this condition is unknown. There is controversy regarding surgical treatment, as the open and arthroscopic approaches to synovectomy have shown comparable reported outcomes in the literature5-7. However, direct comparison of these 2 operative methods is problematic because of selective bias in the existing literature and the lack of any prospective, randomized controlled trials. In the posterior aspect of the knee, arthroscopic synovectomy is technically challenging because of anatomical blind spots when viewing this space from an anterior portal in a trans-notch fashion10-15. Additionally, incomplete arthroscopic synovectomies increase PVNS recurrence rates, making it imperative to remove the entire lesion8. The trans-septal portal (TSP) technique utilizes both posteromedial and posterolateral portals to create an intra-articular portal through the posterior septum that separates the 2 posterior compartments of the knee10-15. This portal allows working instruments to be passed back-and-forth across the posterior septum and increases the visualization of both the posterosuperior synovial lining of the condyles and the synovial reflection behind the posterior cruciate ligament, enabling a thorough assessment for arthroscopic PVNS resection10-16. In this video article, we describe a posterior arthroscopic synovectomy with use of a TSP for PVNS within the posterior compartment of the knee. Description: The patient is positioned such that the contralateral leg will not obstruct the ability to work in the posteromedial portal. Diagnostic arthroscopy is performed through standard anteromedial and anterolateral portals. Next, with visualization from the anterolateral portal and the knee in 90° of flexion, the posteromedial portal is created with use of a transilluminated spinal needle. The posterolateral portal is made in the same fashion as the posteromedial portal, with use of a trans-notch view from the anteromedial portal. With the arthroscope in the posteromedial portal, a blunt instrument or motorized shaver can be placed through the posterolateral portal to perforate the posterior septum and create the TSP. The mass can then be identified, biopsied, and removed with use of a motorized shaver or tissue grasper. Arthroscopic exploration through the TSP can then be done to confirm adequate excision. Alternatives: Alternatives include synovectomy either by arthrotomy, arthroscopy via a posteromedial or posterolateral portal with trans-notch views, or a combination of both. To limit the risk of recurrent diffuse PVNS, radiosynovectomy with yttrium-90 or phosphorus-32, either combined with surgery or alone, has been described2,17. External beam radiation has also been utilized, but radiation toxicity is seen as a major limitation17. Macrophage-colony stimulating factor (M-CSF) or CSF-1 inhibitors have recently been developed. In 2019, the FDA approved the use of CSF-1 inhibitors, and they are considered an acceptable treatment for patients who are not candidates for surgical resection17. Rationale: Advantages involve increased posterior anatomy visualization to ensure adequate synovectomy, more working capacity for instruments, and decreased disruption of anatomical planes and scar tissue formation around neurovascular structures compared with open dissection10-16. Expected Outcomes: Excellent clinical results (defined by return to full knee function) have been reported for the TSP technique for PVNS synovectomy. In a study of 10 cases of posterior-knee PVNS masses removed via arthroscopic synovectomy with use of a TSP, Shekhar et al. reported good functional outcomes and no operative complications2. Keyhani et al. reported a series of 21 patients who underwent the same procedure for diffuse PVNS with similar findings9. Patients can expect to retain close to full knee function following this procedure2,9. Baseline magnetic resonance imaging is recommended for all patients at 3 to 6 months after excision, as asymptomatic recurrence can occur, and patients should be followed for a minimum of 2 years post-excision2,3,7,9,18. Important Tips: Keeping the knee in 90° of flexion provides the furthest distance from the saphenous vein on the medial side, the peroneal nerve on the lateral side, and the popliteal artery near the posterior septum when making the posterior portals10-16.Transillumination of the posterior portals is recommended10-16.Perforation of the septum should be in the posterolateral to posteromedial direction, allowing surgeons to have a wider "safe zone" to decrease the chance of vascular injury to the popliteal artery14. Acronyms and Abbreviations: CSF = colony-stimulating factorMCL = medial collateral ligamentMRI = magnetic resonance imagingPL = posterolateralPM = posteromedialPA = popliteal arteryROM = range of motionTS = trans-septalIKDC = International Knee Documentation Committee.

Preoperative Magnetic Resonance Imaging Offers Questionable Clinical Utility, Delays Time to Hip Arthroscopy, and Lacks Cost-Effectiveness in Patients Aged ≤40 Years With Femoroacetabular Impingement Syndrome: A Retrospective 5-Year Analysis.

PURPOSE: To assess the clinical utility of preoperative magnetic resonance imaging (MRI) and quantify the delay in surgical care for patients aged ≤40 years undergoing primary hip arthroscopy with history, physical examination, and radiographs concordant with femoroacetabular impingement syndrome (FAIS). METHODS: From August 2015 to December 2020, 1,786 consecutive patients were reviewed from the practice of 1 fellowship-trained hip arthroscopist. Inclusion criteria were FAIS, primary surgery, and age ≤40 years. Exclusion criteria were MRI contraindication, reattempt of conservative management, or concomitant periacetabular osteotomy. After nonoperative treatment options were exhausted and a surgical plan was established, patients were stratified by those who presented with versus without MRI. Those without existing MRI received one, and any deviations from the surgical plan were noted. All preoperative MRIs were compared with office evaluation and intraoperative findings to assess agreement. Demographic data, Hip Disability and Osteoarthritis Outcome Score (HOOS)-Pain, and time from office to MRI or arthroscopy were recorded. RESULTS: Of the patients indicated by history, physical examination, and radiographs alone (70% female, body mass index 24.8 kg/m2, age 25.9 years), 198 patients presented without MRI and 934 with MRI. None of the 198 had surgical plans altered after MRI. Patients in both groups had MRI findings demonstrating anterosuperior labral tears that were visualized and repaired intraoperatively. Mean time from office to arthroscopy for patients without MRI versus those with was 107.0 ± 67 and 85.0 ± 53 days, respectively (P < .001). Time to MRI was 22.8 days. No difference between groups was observed among the 85% of patients who surpassed the HOOS-Pain minimal clinically important difference (MCID). CONCLUSION: Once indicated for surgery based on history, physical examination, and radiographs, preoperative MRI did not alter the surgical plan for patients aged ≤40 years with FAIS undergoing primary hip arthroscopy. Moreover, preoperative MRI delayed time to arthroscopy. The necessity of routine preoperative MRI in the young primary FAIS population should be challenged.

Design Features and Rationale of the BEAR-MOON (Bridge-Enhanced ACL Restoration Multicenter Orthopaedic Outcomes Network) Randomized Clinical Trial.

BACKGROUND: BEAR (bridge-enhanced anterior cruciate ligament [ACL] restoration), a paradigm-shifting technology to heal midsubstance ACL tears, has been demonstrated to be effective in a single-center 2:1 randomized controlled trial (RCT) versus hamstring ACL reconstruction. Widespread dissemination of BEAR into clinical practice should also be informed by a multicenter RCT to demonstrate exportability and compare efficacy with bone--patellar tendon-bone (BPTB) ACL reconstruction, another clinically standard treatment. PURPOSE: To present the design and initial preparation of a multicenter RCT of BEAR versus BPTB ACL reconstruction (the BEAR: Multicenter Orthopaedic Outcomes Network [BEAR-MOON] trial). Design and analytic issues in planning the complex BEAR-MOON trial, involving the US National Institute of Arthritis and Musculoskeletal and Skin Diseases, the US Food and Drug Administration, the BEAR implant manufacturer, a data and safety monitoring board, and institutional review boards, can usefully inform both clinicians on the trial's strengths and limitations and future investigators on planning of complex orthopaedic studies. STUDY DESIGN: Clinical trial. METHODS: We describe the distinctive clinical, methodological, and operational challenges of comparing the innovative BEAR procedure with the well-established BPTB operation, and we outline the clinical motivation, experimental setting, study design, surgical challenges, rehabilitation, outcome measures, and planned analysis of the BEAR-MOON trial. RESULTS: BEAR-MOON is a 6-center, 12-surgeon, 200-patient randomized, partially blinded, noninferiority RCT comparing BEAR with BPTB ACL reconstruction for treating first-time midsubstance ACL tears. Noninferiority of BEAR relative to BPTB will be claimed if the total score on the International Knee Documentation Committee (IKDC) subjective knee evaluation form and the knee arthrometer 30-lb (13.61-kg) side-to-side laxity difference are both within respective margins of 16 points for the IKDC and 2.5 mm for knee laxity. CONCLUSION: Major issues include patient selection, need for intraoperative randomization and treatment-specific postoperative physical therapy regimens (because of fundamental differences in surgical technique, initial stability construct, and healing), and choice of noninferiority margins for short-term efficacy outcomes of a novel intervention with evident short-term advantages and theoretical, but unverified, long-term benefits on other dimensions.

Treatment options for complex shoulder osteoarthritis with posterior humeral head subluxation and glenoid bone loss (Walch B): A systematic review.

Background: Shoulder osteoarthritis (OA) with eccentric (B) glenoids has generally been associated with poor patient-reported outcomes and increased complications. The purpose of this study was to outline all the described treatment options and their outcomes and complications in order to better guide treatment. Methods: This systematic review was performed according to the Preferred Reporting Items for Systematic review and Meta-analysis guidelines. Searches were performed up to December 19, 2019, using Medline, EMBASE, Scopus, and Cochrane databases. Inclusion criteria included studies for glenohumeral OA reporting posterior humeral head subluxation and/or posterior glenoid erosion. Studies were excluded if they were review papers, abstracts, or conference papers; had heterogeneity of included Walch types; or were not written in English. Results: Twenty-one studies met inclusion criteria. The mean follow-up duration was 47.5 months (range, 14-300), and the mean patient age 62 years (38-88). Six different discernible techniques were identified: asymmetric reaming with onlay glenoid (AROG) in 267 shoulders, posterior glenoid bone grafting (PGBG) with onlay glenoid in 79 shoulders, augmented glenoid (AG) in 160 shoulders, reverse shoulder arthroplasty (RSA) with or without bone grafting in 118 shoulders, hemiarthroplasty with concentric reaming (HACR) in 57 shoulders, and humeral head arthroplasty with inlay glenoid (HAIG) in 36 shoulders. All techniques reported improved patient outcomes and range of motion. Short-term (<5 years) studies reported glenoid loosening leading to revisions in 3% of AROG, 2.7% PGBG, 0.8% AG, 1.4% RSA, and 0% HAIG shoulders. HACR had a high revision rate (12.3%) due to persistent pain and stiffness. Midterm (>5 years) studies demonstrated increased rates of glenoid loosening with AROG (14.5%), PGBG (21% loose, 23.8% "at risk"), and AG (18.9% "at risk"), as well as increased rates of subluxation or revision due to instability. HAIG did not demonstrate loosening, subluxation, or revision at 55.2 months. Conclusion: Various techniques exist to manage complex primary glenohumeral OA with posterior subluxation and posterior glenoid erosion. Glenoid component survival is a concern with ASOG, PGBG, and AG. HACR has the highest early revision rate. RSA offers promising short-term and midterm results likely due to the advantage of more secure fixation as well as a constrained design to prevent posterior subluxation. HAIG has the lowest complication and revision rates although further long-term studies are needed.

BTA-MM: Burst traffic awareness-based adaptive mobility model with mobile sinks for heterogeneous wireless sensor networks.

Using mobile sink increases the coverage time and energy expenditure when there is a burst traffic condition in wireless sensor networks (WSNs). Hence, it is essential to handle burst traffic using mobile sinks in an energy-efficient mobility manner. In most studies, mechanisms of the clustering and routing have not taken into account burst traffic. In fact, the number of studies with integrated mobile sink nodes, burst traffic awareness, multi-criteria cluster head (CH) selection, and mobile sink routing is negligible. For this purpose, a novel burst traffic awareness adaptive mobility scheme is proposed based on heterogeneous clustered WSNs, namely Burst Traffic Awareness-Mobility Model (BTA-MM). In the proposed scheme, the network area is first divided into two cluster groups. The CH selection is performed for each round by the average residual energy an d node load, taking into account the network coverage. An adaptive Gauss-Markov-burst traffic combination model is proposed in the study. In the proposed model, the mobile sinks collect all data in a single-hop communication as soon as they join the coverage intersection points (CIPs) of the CHs. The mobility model utilizes the adaptive minimum-weighted cost of the nodes. Once the burst packets are perceived in a CH, the data packets are backed up on the nearest and highest energy node in the cluster. Then, the mobile sink suddenly updates its trajectory towards the node, including the burst data traffic. Performance analysis of the proposed scheme was performed in NS-2 simulation environment. The most notable of the performance results is that the proposed method increased the network lifetime 42.5% more than any other method and also reduced the control overhead and average mobile path length by 72.5% and 35.9%, respectively. Also, the simulation results showed that the proposed method significantly reduced the average energy consumption 34.2% more than any other method, and increased the packet delivery rate 4.5% more than any other method, even in burst traffic.

Twenty-Year Outcomes After Anterior Cruciate Ligament Reconstruction: A Systematic Review of Prospectively Collected Data.

BACKGROUND: Several long-term (≥20 years) follow-up studies after anterior cruciate ligament (ACL) reconstruction have been published in recent years, allowing for a systematic evaluation of outcomes. PURPOSE: To summarize outcomes at ≥20 years after ACL reconstruction and identify patient and surgical factors that affect these results. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: Prospective studies of primary ACL reconstructions with hamstring or bone-patellar tendon-bone (BTB) autograft via an arthroscopic or a mini-open technique and with a mean follow-up of ≥20 years were identified. When possible, the mean scores for each outcome measure were calculated. Factors identified in individual studies as predictive of outcomes were described. RESULTS: Five studies met the inclusion and exclusion criteria with a total of 2012 patients. The pooled mean follow-up for patient-reported outcome measures was 44.2% (range, 29.6%-92.7%) and in-person evaluation was 33.2% (range, 29.6%-48.9%). Four studies (n = 584) reported graft tears at a mean rate of 11.8% (range, 2%-18.5%) and 4 studies (n = 773) reported a contralateral ACL injury rate of 12.2% (range, 5.8%-30%). Repeat non-ACL arthroscopic surgery (4 studies; n = 177) to the ipsilateral knee occurred in 10.4% (range, 9.5%-18.3%) and knee arthroplasty (1 study; n = 217) in 5%. The pooled mean of the International Knee Documentation Committee subjective knee function (IKDC) score was 79.1 (SD, 21.8 [3 studies; n = 644]). In 2 studies (n?= 221), 57.5% of patients continued to participate in strenuous activities. The IKDC-objective score was normal or nearly normal in 82.3% (n = 496; 3 studies), with low rates of clinically significant residual laxity. Moderate-severe radiographic osteoarthritis (OA) (IKDC grade C or D) was present in 25.9% of patients (n = 605; 3 studies). Medial meniscectomy is associated with increased risk of radiographic OA. Radiographic OA severity is associated with worse patient-reported knee function, but the association with knee pain is unclear. CONCLUSION: Currently available prospective evidence for ACL reconstruction with hamstring or BTB autograft provides several insights into outcomes at 20 years. The rates of follow-up at 20 years range from 30% to 93%. IKDC-objective scores were normal or nearly normal in 82% and the mean IKDC-subjective score was 79 points.

Outcomes of Pediatric Posterior Cruciate Ligament Reconstruction: A Systematic Review.

BACKGROUND: Little has been reported in the literature regarding surgical treatment of posterior cruciate ligament (PCL) injuries in pediatric patients. PURPOSE/HYPOTHESIS: The purpose was to evaluate presentation, injury pattern, outcomes, and complications of surgically managed PCL injuries in pediatric patients. It was hypothesized that pediatric patients would have good patient-reported outcomes and no significant radiographic changes or complications. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A literature search was performed using PubMed, Medline, EMBASE, Scopus, and Cochrane databases between 1975 and December 16, 2019. Search terms included "posterior cruciate ligament," "peel-off injury," "avulsion," "PCL," "pediatric," "skeletally immature," and "adolescent." Included were studies on pediatric patients with PCL injuries managed operatively. Exclusion criteria included case reports, studies not reporting clinical results, reviews, abstract or conference papers, or papers not in the English language. Quality assessment was performed on all included studies using the MINORS (Methodological Index for Non-Randomized Studies) criteria. RESULTS: Four articles comprising 43 knees in 42 patients met the criteria and were included. Motor vehicle accidents were the most common mechanism of injury (39.5%; n = 17/43), followed by sports-related injuries (35%; n = 15/43). All studies commented on tear pattern, with the following distribution: 42% (n = 18/43) midsubstance tears, 37% (n = 16/43) tibial avulsions, and 21% (n = 9/43) femoral avulsions. Overall, good patient-reported outcomes (Knee injury and Osteoarthritis Outcome Score and Pediatric International Knee Documentation Committee, Tegner, and Lysholm scores) and return to activity, as well as satisfactory posterior stability (KT-1000 arthrometer, posterior drawer test, and kneeling radiographs) and range of motion, were reported. There was no significant leg-length discrepancy or angular deformity reported. Arthrofibrosis was reported in 7% of postoperative knees and was the most commonly reported complication. Osteoarthritis was reported in 21% (n = 9/43) of knees. The average MINORS score was 7 (range, 6-8) for noncomparative studies and 10 for comparative studies. CONCLUSION: Good patient-reported outcomes and return to activity can be obtained using repair or reconstruction. This evidence was limited by the quality of the included studies and overall small sample size; however, this review serves as a baseline for futures studies on PCL repair/reconstruction in pediatric patients.

Clinical and Radiographic Outcomes of Total Shoulder Arthroplasty With a Nonspherical Humeral Head and Inlay Glenoid in Elite Weight Lifters: A Prospective Case Series.

BACKGROUND: Weight lifting after total shoulder arthroplasty (TSA) can place significant stresses on implants that could lead to instability, loosening, and increased wear. A TSA system with nonspherical humeral head resurfacing and inlay glenoid-which improves the biomechanics and thus reduces instability, wear, and potential loosening-may be able to tolerate repetitive loads from weight lifting. PURPOSE: To determine clinical and radiographic outcomes after TSA in weight lifters. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We prospectively enrolled 16 weight lifters (mean ± SD age, 57.2 ± 7.8 years; 15 male) undergoing primary anatomic TSA (n = 17 shoulders, 1 staged bilateral) with nonspherical humeral head resurfacing and inlay glenoid replacement for glenohumeral osteoarthritis between February 2015 and February 2019. Exclusion criteria were rotator cuff deficiency, revision TSA, post-traumatic arthritis, and inflammatory arthritis. Outcome measures included the rate of return to weight lifting, results of patient-reported outcome measures (Penn Shoulder Score, Kerlan-Jobe Orthopaedic Clinic, and 12-Item Veterans RAND Health Survey), radiographic outcomes, and complication rate. RESULTS: Follow-up was obtained on all patients at a mean of 38 months (range, 14-63 months). All patients returned to competitive weight lifting at 15.6 ± 6.9 weeks. Compared to the preoperative weight lifting level, at last follow-up patients reported performance at the following level: lighter weight, 1 (6%); same weight, 8 (50%); heavier weight, 7 (44%). Preoperative eccentric posterior glenoid wear was common (71% Walch B2 classification; 12/17), but posterior humeral subluxation improved at follow-up according to the Walch index (mean, 55.5% preoperative vs 48.5% postoperative; P < .001) and contact point ratio (mean, 63.9% preoperative vs 50.1% postoperative; P < .001). Pre- to postoperative improvements were seen in Penn Shoulder Score (44.3 vs 82.6; P < .001), Kerlan-Jobe Orthopaedic Clinic (50.6 vs 91.1; P < .001), and 12-Item Veterans RAND Health Survey physical component score but not mental component score. No signs of radiographic loosening were detected in follow-up images, nor were there any postoperative instability episodes or revision surgeries. CONCLUSION: There were substantial improvements in shoulder function and a high rate of return to weight lifting after TSA with a nonspherical humeral head resurfacing and inlay glenoid component. Radiographically, the humeral head centralized on the glenoid after surgery, and there was no evidence of component loosening at a mean 38-month follow-up.