Altered purine metabolism at reperfusion affects clinical outcome in lung transplantation.

INTRODUCTION: Lung transplantation is an established treatment for patients with end-stage lung disease. However, ischaemia reperfusion injury remains a barrier to achieving better survival outcomes. Here, we aim to investigate the metabolomic and transcriptomic profiles in human lungs before and after reperfusion, to identify mechanisms relevant to clinical outcome. METHODS: We analysed 67 paired human lung tissue samples collected from 2008 to 2011, at the end of cold preservation and 2 hours after reperfusion. Gene expression analysis was performed with R. Pathway analysis was conducted with Ingenuity Pathway Analysis. MetaboAnalyst and OmicsNet were used for metabolomics analysis and omics data integration, respectively. Association of identified metabolites with transplant outcome was investigated with Kaplan-Meier estimate and Cox proportional hazard models. RESULTS: Activation of energy metabolism and reduced antioxidative biochemicals were found by metabolomics. Upregulation of genes related to cytokines and inflammatory mediators, together with major signalling pathways were revealed by transcriptomics. Purine metabolism was identified as the most significantly enriched pathway at reperfusion, based on integrative analysis of the two omics data sets. Elevated expression of purine nucleoside phosphorylase (PNP) could be attributed to activation of multiple transcriptional pathways. PNP catabolised reactions were evidenced by changes in related metabolites, especially decreased levels of inosine and increased levels of uric acid. Multivariable analyses showed significant association of inosine and uric acid levels with intensive care unit length of stay and ventilation time. CONCLUSION: Oxidative stress, especially through purine metabolism pathway, is a major metabolic event during reperfusion and may contribute to the ischaemia reperfusion injury of lung grafts.

Tranexamic Acid Administration in Arthroscopic Surgery Is a Safe Adjunct to Decrease Postoperative Pain and Swelling: A Systematic Review and Meta-analysis.

PURPOSE: To systematically screen the literature in an effort to critically examine the effect of tranexamic acid (TXA) in patients undergoing arthroscopic surgery, specifically pertaining to pain, blood loss, length of surgery, and both major and minor complications. METHODS: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Revised Assessment of Multiple Systematic Reviews (R-AMSTAR) guidelines, 3 databases (MEDLINE, EMBASE, and Cochrane) were searched April 2020 and screened in duplicate using inclusion and exclusion criteria for studies on the given subject. Study findings were reviewed, and meta-analysis was then performed on sufficiently congruent data using a random-effects model. RESULTS: There were 7 eligible randomized controlled trials, with 724 total patients, undergoing anterior cruciate ligament reconstruction (4 studies, 537 patients), meniscectomy (1 study, 45 patients), femoroacetabular impingement (1 study, 70 patients), or rotator cuff repair (1 study, 72 patients). The mean age throughout the included studies was 33.9 years, with a mean of 27.7% female patients. There was a 1% drop out rate at 3 months postoperatively. There were significantly lower visual analog scale scores at 2 weeks postoperatively in the TXA groups (mean difference: -1.65, 95% confidence interval [CI] -3.41 to 0.10, P = .06, I2 = 97%). Furthermore, there was a significant decrease in the number of patients requiring joint aspiration in the TXA groups (risk ratio 0.27, 95% CI 0.12-0.56, I2 = 0%, P = .0006). The drainage output in TXA groups was also significantly decreased (mean difference: -61.14 mL, 95% CI -104.43 to -17.85, I2 = 94%, P = .006). Furthermore, there was a statistically significant decrease in hemarthrosis grade (Coupens & Yates) at 2 weeks postoperatively (Mean difference: -0.76, 95% CI -0.97 to -0.54, I2 = 0%, P < .0001). Finally, there was no significant difference in operating time, across all studies (Mean difference: 0.53, 95% CI -3.43 to 4.50, I2 = 57%, P < .79). The use of TXA showed no increased incidence of deep vein thrombosis, infection, arthrofibrosis, or other major complications or adverse reactions between the TXA and control groups. CONCLUSIONS: This systematic review and meta-analysis of randomized controlled trialss found that the use of TXA significantly improves pain scores up to 6 weeks postoperatively, decreases drainage output, decreases the need for joint aspirations, decreases incidence of hemarthrosis, increases visual clarity and technical ease, and has no increased incidence of other complications, at no loss to operative time. These findings indicate that TXA may be a useful adjunct in arthroscopic knee and shoulder surgery. LEVEL OF EVIDENCE: II.

Transcriptomic investigation reveals donor-specific gene signatures in human lung transplants.

INTRODUCTION: Transplantation of lungs from donation after circulatory death (DCD) in addition to donation after brain death (DBD) became routine worldwide to address the global organ shortage. The development of ex vivo lung perfusion (EVLP) for donor lung assessment and repair contributed to the increased use of DCD lungs. We hypothesise that a better understanding of the differences between lungs from DBD and DCD donors, and between EVLP and directly transplanted (non-EVLP) lungs, will lead to the discovery of the injury-specific targets for donor lung repair and reconditioning. METHODS: Tissue biopsies from human DBD (n=177) and DCD (n=65) donor lungs, assessed with or without EVLP, were collected at the end of cold ischaemic time. All samples were processed with microarray assays. Gene expression, network and pathway analyses were performed using R, Ingenuity Pathway Analysis and STRING. Results were validated with protein assays, multiple logistic regression and 10-fold cross-validation. RESULTS: Our analyses showed that lungs from DBD donors have upregulation of inflammatory cytokines and pathways. In contrast, DCD lungs display a transcriptome signature of pathways associated with cell death, apoptosis and necrosis. Network centrality revealed specific drug targets to rehabilitate DBD lungs. Moreover, in DBD lungs, tumour necrosis factor receptor-1/2 signalling pathways and macrophage migration inhibitory factor-associated pathways were activated in the EVLP group. A panel of genes that differentiate the EVLP from the non-EVLP group in DBD lungs was identified. CONCLUSION: The examination of gene expression profiling indicates that DBD and DCD lungs have distinguishable biological transcriptome signatures.

No decrease in incidence of arthroscopic meniscectomy in a Canadian province.

PURPOSE: Arthroscopic meniscectomy (APM) is the most common procedure in orthopedic surgery, despite increasing evidence questioning its benefit over conservative management for treatment of degenerative meniscal tears. The purpose of this study is to determine the epidemiology and trends of APM in Saskatchewan, a Canadian province, over a 20 year period. METHODS: Physician billing codes were used to identify patients who underwent APM in Saskatchewan between January 1, 1998 and December 31, 2017. Records were obtained from eHealth Saskatchewan, a provincial health database. Data was analyzed for overall incidence and age-specific trends of APM. RESULTS: A total of 35,099 APMs were performed during the study period. The population of Saskatchewan ranged from 992,314 to 1,150,782 (median 1,017,368) during this time interval, with 81 orthopedic surgeons performing APM. Overall incidence rate of APM did not change significantly over time. No decrease was observed in patients presumed to have degenerative tears (≥ 50 years). The number of meniscectomies in patients ≥ 50 years was significantly greater during the second decade of study compared to the first (OR 1.48, p < 0.01). Conversely, the increase in incidence rate among older patients was not statistically significant (R2 = 0.125, n.s.). CONCLUSION: Overall incidence rate of APM in Saskatchewan has not decreased during the last 20 years. Furthermore, APM frequency increased over time for individuals ≥ 50 years. Several regional factors may have contributed to these findings, including the large proportion of Saskatchewan residents engaged in physically demanding work and barriers to accessing physiotherapy services. Given recent evidence disputing the benefit of APM over conservative measures, this study highlights the need for improved dissemination of evidence, as well as the importance of an individualized treatment plan to address patient-specific factors. LEVEL OF EVIDENCE: Level IV.

Editorial Commentary: Anterior Capsular Reconstruction for Subscapularis Deficiency: The Definitive Treatment or a Helpful Adjunct?

Anterior glenohumeral instability in the setting of irreparable subscapularis deficiency represents a difficult clinical scenario for the treating shoulder surgeon. Anterior capsular reconstruction with humeral dermal allograft improved glenohumeral translation stability and range of motion to near-normal values whereas pectoralis major tendon transfer was unable to do so. However, placement of a static spacer does not restore the dynamic force couple or shoulder kinematics. Further research is needed to evaluate the functional outcomes using this reconstruction technique.

Subpectoral Biceps Tenodesis With PEEK Interference Screw: A Biomechanical Analysis of Humeral Fracture Risk.

PURPOSE: To quantify the torsional load to fracture for subpectoral biceps tenodesis with interference screw fixation. METHODS: We randomized 28 specimens from 14 matched-pair full-length humeri (mean age, 55.3 years) into 3 groups: (1) empty ream group (ERG), (2) screw-only group (SOG), and (3) screw-plus-biceps tendon group (SBG). In each group, 1 humerus of each matched pair was prepared according to group allocation and the contralateral humerus remained intact as a control. In the ERG, an 8-mm unicortical hole was reamed 1 cm proximal to the inferior border of the pectoralis major tendon insertion; in the SOG, the humerus was filled with an 8-mm × 12-mm PEEK (polyether ether ketone) screw; and in the SBG, the humerus was filled with a PEEK screw and the cadaveric long head of the biceps tendon. Humeri were tested under torsional displacement at a rate of 1°/s until fracture. Maximum torque, energy to maximum torque, and linear stiffness were used to assess humerus strength. RESULTS: Compared with contralateral intact specimens, the maximum torque to fracture was reduced by 28% in the ERG (P = .005), 30% in the SOG (P = .014), and 20% in the SBG (P = .046). Energy to maximum torque was similarly reduced in the ERG (P = .007), SOG (P = .023), and SBG (P = .049). Stiffness was increased by 4% in the ERG (P = .498), 9% in the SOG (P = .030), and 4% in the SBG (P = .439). CONCLUSIONS: Drilling an 8-mm unicortical hole in zone 3 of the bicipital tunnel for open subpectoral biceps tenodesis reduces the torsional load to humeral fracture up to 28% at time 0. The addition of a PEEK tenodesis screw alone reduced the maximum torque by 30%, and the addition of a screw with the long head of the biceps tendon reduced the maximum torque by 20%. The total load to fracture was reduced in all settings. Stiffness was not significantly different for the ERG and SBG, but stiffness was significantly higher for the SOG compared with the intact matched humeri at time 0. CLINICAL RELEVANCE: When performing a biceps tenodesis, humeral fracture susceptibility is increased with an applied torsional load at time 0. Thus providers must be aware of this reduced integrity when a subpectoral biceps tenodesis is used.

Level of evidence and authorship trends of clinical studies in knee surgery, sports traumatology, arthroscopy, 1995-2015.

PURPOSE: There is increasing emphasis on publication quality and internationalization of author groups in orthopaedic literature. The purpose of this review was to evaluate the type of studies and the level of evidence (LOE) published in knee surgery, sports traumatology, arthroscopy (KSSTA) from 1995 to 2015. The secondary aim was to analyze trends in authorship characteristics in KSSTA. METHODS: Two reviewers reviewed the table of contents of KSSTA and identified original papers from 1995, 2000, 2005, 2010, and 2015. The reviewers graded LOE from Levels I to IV using guidelines from the University of Oxford's Centre for Evidence-Based Medicine. For each article, the total number of authors and country of author group were also analyzed. RESULTS: A total of 880 papers were analyzed. The proportions in LOE have stayed consistent throughout the study period (n.s.). There has been a significant increase in the number of published articles and the number of Level I and II studies (P < 0.01). Therapeutic articles were the most common type. The mean number of authors per KSSTA article significantly increased from 3.9 to 5.7 over the 20-year period (P < 0.01). The number of represented countries increased yearly and academic institutions from 40 different nationalities published articles in the Journal. Of the examined years, the percent of articles with international collaboration was 17.6%. CONCLUSION: The proportion of LOE I and II articles published in KSSTA remains consistently high. Therapeutic studies are the most frequently published articles. There is an increase in international groups publishing in KSSTA. LEVEL OF EVIDENCE: IV.

The Anterolateral Ligament is Not the Whole Story: Reconsidering the Form and Function of the Anterolateral Knee and its Contribution to Rotatory Knee Instability.

The heterogeneity of available cadaveric, histologic, and radiographic results related to the anterolateral ligament (ALL) does not support its existence as a discrete anatomic structure. Moreover, focusing narrowly on the ALL in isolation, what has previously been referred to as "ALL myopia," obscures a thorough appreciation for the stability contributions of both capsular and extracapsular structures. We consider injury to the soft tissues of the anterolateral knee-the anterolateral complex-just one component of what is frequently found to be a spectrum of pathology observed in the rotationally unstable, anterior cruciate ligament (ACL)-deficient knee. Increased lateral tibial slope, meniscal root tears, and "ramp" lesions of the medial meniscocapsular junction have all been implicated in persistent rotatory knee instability, and the restoration of rotational stability requires a stepwise approach to the assessment of each of these entities. Through an appreciation for the multifactorial nature of rotatory knee instability, surgeons will be better equipped to perform durable ACL reconstructions that maximize the likelihood of optimal clinical outcomes for patients. The purposes of this review are to provide an update on the relevant anatomy of the anterolateral knee soft tissues and to explain the multifactorial nature of rotatory knee instability in the setting of ACL deficiency.

Variability in Outcome Reporting for Operatively Managed Anterior Glenohumeral Instability: A Systematic Review.

PURPOSE: The purpose of this study was to quantify the degree of variability in outcomes assessed after surgery for anterior shoulder instability in recent high-impact literature. METHODS: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, an extensive review of the literature during a 5-year period from January 2011 through December 2015 was performed across 6 orthopaedic journals with high impact factors to identify all studies investigating outcomes after anterior shoulder instability. Studies reporting clinical outcomes for patients with anterior glenohumeral instability after surgical treatment with at least 1-year follow-up were included. Several metrics were collected from each manuscript: (1) range of motion (ROM), (2) quantitative strength, (3) physical examination testing, (4) imaging, (5) patient-reported outcomes (PROs), (6) complications (including recurrent instability), (7) patient satisfaction, and (8) return to preinjury level of activity or sport. Variability in outcome measures was then qualitatively assessed. RESULTS: Sixty-eight studies were included for final analysis ranging from Level I to IV evidence. Fifty-nine percent reported ROM, and 18% measured strength. Other clinical exam maneuvers were assessed in 44%, with 40% assessing apprehension. Imaging was used in 62%, including X-rays, magnetic resonance imaging, and computed tomography scans. On average, 2.25 PROs were assessed. In total, 28 different PROs were used to assess outcomes. The 3 most commonly reported PROs were the Rowe scale at 46%, the Western Ontario Shoulder Instability Index at 31%, and the Constant Shoulder Score at 26%. Twenty-five percent included patient satisfaction in their assessment of outcomes. Recurrence was assessed by 59%, and return to preinjury level of activity was reported by 37% of the studies. CONCLUSIONS: There is substantial variability in outcome reporting for high-impact anterior shoulder instability literature with 28 different outcome tools used, making it difficult to compare outcomes between studies. Agreeing upon a uniform measure to assess outcomes would allow for clearer interpretation of the literature as well as the potential to draw conclusions from pooled data. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

Three-Dimensional Magnetic Resonance Imaging Quantification of Glenoid Bone Loss Is Equivalent to 3-Dimensional Computed Tomography Quantification: Cadaveric Study.

PURPOSE: To assess the ability of 3-dimensional (3D) magnetic resonance imaging (MRI, 1.5 and 3 tesla [T]) to quantify glenoid bone loss in a cadaveric model compared with the current gold standard, 3D computed tomography (CT). METHODS: Six cadaveric shoulders were used to create a bone loss model, leaving the surrounding soft tissues intact. The anteroposterior (AP) dimension of the glenoid was measured at the glenoid equator and after soft tissue layer closure the specimen underwent scanning (CT, 1.5-T MRI, and 3-T MRI) with the following methods (0%, 10%, and 25% defect by area). Raw axial data from the scans were segmented using manual mask manipulation for bone and reconstructed using Mimics software to obtain a 3D en face glenoid view. Using calibrated Digital Imaging and Communications in Medicine images, the diameter of the glenoid at the equator and the area of the glenoid defect was measured on all imaging modalities. RESULTS: In specimens with 10% or 25% defects, no difference was detected between imaging modalities when comparing the measured defect size (10% defect P = .27, 25% defect P = .73). All 3 modalities demonstrated a strong correlation with the actual defect size (CT, ρ = .97; 1.5-T MRI, ρ = .93; 3-T MRI, ρ = .92, P < .0001). When looking at the absolute difference between the actual and measured defect area, no significance was noted between imaging modalities (10% defect P = .34, 25% defect P = .47). The error of 3-T 3D MRI increased with increasing defect size (P = .02). CONCLUSIONS: Both 1.5- and 3-T-based 3D MRI reconstructions of glenoid bone loss correlate with measurements from 3D CT scan data and actual defect size in a cadaveric model. Regardless of imaging modality, the error in bone loss measurement tends to increase with increased defect size. Use of 3D MRI in the setting of shoulder instability could obviate the need for CT scans. CLINICAL RELEVANCE: The goal of our work was to develop a reproducible method of determining glenoid bone loss from 3D MRI data and hence eliminate the need for CT scans in this setting. This will lead to decreased cost of care as well as decreased radiation exposure to patients. The long-term goal is a fully automated system that is as approachable for clinicians as current 3D CT technology.

Biomechanical Analysis of Latarjet Screw Fixation: Comparison of Screw Types and Fixation Methods.

PURPOSE: To compare the initial fixation stability, failure strength, and mode of failure of 5 different screw types and fixation methods commonly used for the classic Latarjet procedure. METHODS: Thirty-five fresh-frozen cadaveric shoulder specimens were allocated into 5 groups. A 25% anteroinferior glenoid defect was created, and a classic Latarjet coracoid transfer procedure was performed. All grafts were fixed with 2 screws, differing by screw type and/or fixation method. The groups included partially threaded solid 4.0-mm cancellous screws with bicortical fixation, partially threaded solid 4.0-mm cancellous screws with unicortical fixation, fully threaded solid 3.5-mm cortical screws with bicortical fixation, partially threaded cannulated 4.0-mm cancellous screws with bicortical fixation, and partially threaded cannulated 4.0-mm captured screws with bicortical fixation. All screws were stainless steel. Outcomes included cyclic creep and secant stiffness during cyclic loading, as well as load and work to failure during the failure test. Intergroup comparisons were made by a 1-way analysis of variance. RESULTS: There were no significant differences among different screw types or fixation methods in cyclic creep or secant stiffness after cyclic loading or in load to failure or work to failure during the failure test. Post-failure radiographs showed evidence of screw bending in only 1 specimen that underwent the Latarjet procedure with partially threaded solid cancellous screws with bicortical fixation. The mode of failure for all specimens analyzed was screw cutout. CONCLUSIONS: In this biomechanical study, screw type and fixation method did not significantly influence biomechanical performance in a classic Latarjet procedure. When performing this procedure, surgeons may continue to select the screw type and method of fixation (unicortical or bicortical) based on preference; however, further studies are required to determine the optimal method of treatment. CLINICAL RELEVANCE: Surgeons may choose the screw type and fixation method based on preference when performing the Latarjet procedure.

Midterm results of osteochondral allograft transplantation to the humeral head.

BACKGROUND: This study evaluated clinical outcomes of osteochondral allograft (OCA) transplantation for humeral head osteochondral defects. We hypothesized that patients with isolated humeral head disease would achieve favorable results and that patients with bipolar disease would experience inferior outcomes. METHODS: We identified patients who underwent humeral head OCA transplantation. Subjective questionnaire data were obtained preoperatively and at a minimum of 2 years postoperatively. Radiographs were evaluated for graft incorporation. Failure was defined by conversion to shoulder arthroplasty, American Shoulder and Elbow Surgeons score <50, or dissatisfaction with the surgical result. RESULTS: Twenty patients (65% male) met inclusion criteria. Patients were an average age of 24.8 ± 8.1 years. Eleven patients underwent concomitant glenoid surgery (microfracture or meniscal allograft resurfacing). Follow-up was available for 18 patients (90%) at mean of 67 months. All grafts incorporated except 2. Four patients underwent shoulder arthroplasty at mean of 25 months postoperatively (all after pain pump chondrolysis). Eleven of the 20 patients were satisfied (all dissatisfied patients underwent glenoid surgery). Significant improvements (P < .001) were seen for the visual analog scale (from 6.1 to 1.5), Simple Shoulder Test (from 32 to 73), American Shoulder and Elbow Surgeons score (from 39 to 76), and the physical component of the 12-Item Short Form Survey (from 38 to 48). Pain pump patients who did not progress to arthroplasty experienced inferior satisfaction (40% vs. 87.5%, P = .04) and a trend toward inferior outcomes compared with the rest of the cohort. CONCLUSION: OCA transplantation is a viable option for young patients with isolated humeral chondral injury. Patients with bipolar disease or a history of intra-articular pain pump have increased failure and decreased subjective outcomes.

Pectoralis major transfer for treatment of irreparable subscapularis tear: a systematic review.

PURPOSE: Irreparable ruptures of the subscapularis tendon lead to impaired function of the shoulder and presents a surgically complex problem. Transfer of the pectoralis major tendon has been reported as a possible treatment option. The purpose of this systematic review is to critically examine the outcomes of pectoralis major transfers for the treatment of irreparable subscapularis tears. METHODS: A systematic review of the literature was performed using search of electronic databases. No language restrictions were applied. Case reports, review articles, and operative techniques without outcome data were excluded. All the outcomes reported by each study were analyzed and when possible, data were pooled to generate frequency-weighted values to summarize outcomes. RESULTS: Eight studies with a total 195 shoulders were included in this systematic review. The mean age of patients was 58.8 years (range 18-81 years) and the mean follow-up was 33.4 months (range 6-80 months). Constant scores improved from a mean pre-operative score of 37.8 ± 6.8, to a mean postoperative score of 61.3 ± 6.5 (p < 0.0001). Pain scores could not be pooled as different scales were used. Nevertheless, a trend in pain reduction was noted in all papers. Functional outcomes were less favorable in patients with massive rotator cuff tears or previous shoulder replacements. Moreover, the Constant scores were significantly higher in patients following subcoracoid transfer of the pectoralis major tendon compared to patients who received supracoracoid transfer (p < 0.001). The overall reported incidence of postoperative nerve palsy is low (one transient musculocutaneous nerve palsy and one axillary nerve dysfunction out of 195 cases). CONCLUSIONS: The systematic review based on frequency-weighted means demonstrated improvement in shoulder function, strength and pain relief after pectoralis major transfer for irreparable subscapularis tear. LEVEL OF EVIDENCE: IV.

Topographic analysis of the capitellum and distal femoral condyle: finding the best match for treating osteochondral defects of the humeral capitellum.

PURPOSE: The purpose of this study was to determine the donor zone of most congruent topographic match by comparing 4 donor sites from the femur with 4 potential recipient sites of osteochondritis dissecans at the capitellum. METHODS: Computed tomography was performed on 5 right elbows and 6 right medial and 6 right lateral distal femoral hemicondyles, which included the femoral notch. Three-dimensional computed tomography models were created and exported into point-cloud models. A local coordinate map of the distal humerus and distal femoral articular surfaces was created. The capitellum was compared with the medial and lateral distal femoral condyles, with 2 donor zones in each condyle (medial trochlea and medial intercondylar notch or lateral trochlea and lateral intercondylar notch). In each capitellum 4 combinations of 10-mm defects were simulated (central and lateral, 30° and 45° anterior to shaft of humerus), resulting in 480 capitellum-femur comparative combinations being tested. The capitellum surfaces were virtually placed on a point on the femoral articular surface in 3-dimensional space. The least distances (i.e., the shortest distance from the point in question to the corresponding point in space) between the point clouds on the distal humerus and distal femoral articular surfaces were calculated. RESULTS: There was a less than 0.1-mm difference in the topographic articular surface match among the 4 commonly used donor sites of the distal femur and 4 recipient sites of the capitellum. However, the best match for any given 10-mm capitellar defect (central 30°, central 45°, lateral 30°, and lateral 45°) was the same such that the lateral trochlea on the femur always yielded the best fit compared with the 3 other graft locations (P < .005). CONCLUSIONS: Our results indicate that there is a less than 0.1-mm difference in the topographic articular surface match among the 4 commonly used donor sites of the distal femur and the capitellum. The findings suggest that all 4 donor sites provide close articular matching for the capitellum articular surface, with the lateral trochlea articular surface providing the best match. CLINICAL RELEVANCE: These data suggest that a single donor plug may be obtained from multiple sites in the knee and placed into capitellar lesions with an excellent topographic articular surface match. The findings of our study will be useful to surgeons when managing capitellar osteochondritis dissecans lesions.

Disorders of the long head of the biceps tendon.

The functional importance of the long head of the biceps tendon is a source of debate. Despite the controversy concerning its functional role, the long head of the biceps tendon is a recognized pain generator in the shoulder. Because long head of the biceps tendinopathy is commonly associated with other shoulder pathologies, a thorough assessment and examination are critical to making the correct diagnosis and choosing a management plan. If nonsurgical treatment has failed, biceps tenotomy and biceps tenodesis can provide pain relief. Biceps tenodesis is reserved for young, higher demand patients; requires more rehabilitation time; and has a higher cost. All-arthroscopic proximal tenodesis and distal open subpectoral tenodesis have advantages and disadvantages. Although recent midterm reports suggest slightly better revision and complication rates with subpectoral tenodesis, more studies are needed to verify these findings. Persistent shoulder symptoms after biceps tenodesis commonly occur secondary to missed or untreated associated shoulder pathologies but also may result from mechanical failure of the tenodesis.

Clinical outcomes following revision anterior shoulder arthroscopic capsulolabral stabilization.

INTRODUCTION: Traditionally surgeons have treated failed shoulder instability with open capsulolabral repair. Despite improved instrumentation, technique and familiarity in shoulder arthroscopy, few studies have reported the outcomes of arthroscopic revision shoulder instability repair. The purpose of this study was to assess clinical outcomes in patients following revision shoulder arthroscopic anterior capsulolabral stabilization. MATERIALS AND METHODS: Sixty-two patients (63 shoulders) with failure of primary instability repairs were treated with revision arthroscopic anterior shoulder stabilization at a mean follow-up of 46.9 ± 16.8 months (range 18-78). Clinical outcomes were evaluated using validated patient-reported outcome questionnaires including the American Shoulder and Elbow Surgeons score, Simple Shoulder Test, visual analog pain scale and Western Ontario Shoulder Instability Index. In addition, patients were queried for recurrent instability events (subluxation or dislocation) or revision surgery. RESULTS: At final follow-up, the mean postoperative Western Ontario Shoulder Instability normalized score was 80.1 ± 18.7 (range 15.0-100). There were clinically significant improvements in American Shoulder and Elbow Surgeons scores, Simple Shoulder Test scores and ten-point visual analog scale for pain (P < 0.001). Recurrent instability occurred in 12 shoulders (19.0 %), with number of prior surgeries and hyperlaxity found to be significant risk factor for failure (P < 0.001 and P = 0.04, respectively). CONCLUSION: Revision arthroscopic anterior stabilization of the shoulder can result in satisfactory outcomes in appropriately selected patients who have failed previous capsulolabral repair. An increased number of prior surgeries and hyperlaxity are predictive of poor outcome. STUDY DESIGN: Case series, LOE IV.

Evaluating the quality of Internet information for femoroacetabular impingement.

PURPOSE: The Internet has become a ubiquitous source of medical information for both the patient and the physician. However, the quality of this information is highly variable. We evaluated the quality of Internet information available for femoroacetabular impingement (FAI). METHODS: Four popular search engines were used to collect 100 Web sites containing information on FAI. Web sites were evaluated based on authorship, various content criteria, and the presence of Health On the Net Code of Conduct (HONcode) certification. By use of a novel evaluation system for quality, Web sites were also classified as excellent, high, moderate, poor, or inadequate and were subsequently analyzed. Web sites were evaluated as a group, followed by authorship type, by HONcode certification, and by quality level. RESULTS: Of the Web sites, 73 offered the ability to contact the author, 91 offered a considerable explanation of FAI, 54 provided surgical treatment options, 58 offered nonsurgical treatment options, 27 discussed possible complications, 11 discussed eligibility criteria, 31 discussed rehabilitation, 67 discussed a differential diagnosis, and 48 included peer-reviewed citations. We categorized 40 Web sites as academic, 33 as private, 9 as industry, 9 as public education, and 9 as blogs. Our novel quality evaluation system classified 16 Web sites as excellent, 18 as high, 17 as moderate, 18 as poor, and 31 as inadequate. Only 8% of all evaluated Web sites contained HONcode certification. CONCLUSIONS: We found that the quality of information available on the Internet about FAI was dramatically variable. A significantly large proportion of Web sites were from academic sources, but this did not necessarily indicate higher quality. Sites with HONcode certification showed as much variability in quality as noncertified sites. CLINICAL RELEVANCE: This study increases clinician competence in the available Internet information about FAI and helps them to confidently guide patients to formulate appropriate medical decisions based on high-quality information.

Clinical and functional outcomes after anterior cruciate ligament reconstruction using cortical button fixation versus transfemoral suspensory fixation: a systematic review of randomized controlled trials.

PURPOSE: To compare clinical and functional outcomes after anterior cruciate ligament (ACL) reconstruction using cortical button versus transfemoral suspensory fixation. METHODS: This systematic review was conducted following the Cochrane handbook guidelines and PROSPERO registration. Only Level I and II randomized controlled trials comparing cortical button and transfemoral suspensory fixation in hamstring ACL reconstruction were included. A literature search was performed using electronic databases. The methodologic quality of included studies was assessed using The Cochrane Collaboration's risk-of-bias tool. All outcomes reported by each study were evaluated. Primary outcome measures were postoperative International Knee Documentation Committee (IKDC) and Lysholm knee scores. Statistical analysis was performed using RevMan software (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen). Dichotomous data were reported as risk ratio and 95% confidence intervals. Heterogeneity was assessed using I(2). RESULTS: Five studies involving 317 patients were included. The mean follow-up period was 21.7 ± 7.0 months (range, 12 to 38 months). The mean age of participants was 26.7 ± 1.89 years (range, 16 to 48 years). The Lysholm score, Tegner activity score, and IKDC score were compiled. Clinical assessment was performed by Lachman testing, assessment of side-to-side differences on KT-1000 (MEDmetric, San Diego, CA) testing, and measurements of thigh atrophy, as well as imaging (radiography and computed tomography) to assess for femoral tunnel widening. Pooled statistical analysis was possible only for postoperative IKDC and Lysholm scores. No significant differences were found between the cortical button and transfemoral fixation groups. Included studies did not report differences in clinical outcomes between the 2 groups. Radiographic results suggest increased femoral tunnel widening in the cortical button group. However, tunnel widening was not found to affect clinical results. CONCLUSIONS: The present evidence suggests that there are no short- to medium-term differences in knee-specific outcome measures between patients treated with cortical button femoral graft fixation and those treated with suspensory transfemoral fixation when undergoing ACL reconstruction. In addition, radiologic evidence of tunnel widening does not seem to affect short- to medium-term clinical outcomes. LEVEL OF EVIDENCE: Level II, systematic review of Level I and II studies.

Engineering Bipolar Interfaces for Water Electrolysis Using Earth-Abundant Anodes.

Developing efficient and low-cost water electrolyzers for clean hydrogen production to reduce the carbon footprint of traditional hard-to-decarbonize sectors is a grand challenge toward tackling climate change. Bipolar-based water electrolysis combines the benefits of kinetically more favorable half-reactions and relatively inexpensive cell components compared to incumbent technologies, yet it has been shown to have limited performance. Here, we develop and test a bipolar-interface water electrolyzer (BPIWE) by combining an alkaline anode porous transport electrode with an acidic catalyst-coated membrane. The role of TiO2 as a water dissociation (WD) catalyst is investigated at three representative loadings, which indicates the importance of balancing ionic conductivity and WD activity derived from the electric field for optimal TiO2 loading. The optimized BPIWE exhibits negligible performance degradation up to 500 h at 400 mA cm-2 fed with pure water using earth-abundant anode materials. Our experimental findings provide insights into designing bipolar-based electrochemical devices.

Use of metabolomics to identify strategies to improve and prolong ex vivo lung perfusion for lung transplants.

BACKGROUND: Normothermic ex vivo lung perfusion (EVLP) allows for functional assessment of donor lungs; thus has increased the use of marginal lungs for transplantation. To extend EVLP for advanced organ reconditioning and regenerative interventions, cellular metabolic changes need to be understood. We sought to comprehensively characterize the dynamic metabolic changes of the lungs during EVLP, and to identify strategies to improve EVLP. METHODS: Human donor lungs (n = 50) were assessed under a 4-hour Toronto EVLP protocol. EVLP perfusate was sampled at first (EVLP-1h) and fourth hour (EVLP-4h) of perfusion and were submitted for mass spectrometry-based untargeted metabolic profiling. Differentially expressed metabolites between the 2 timepoints were identified and analyzed from the samples of lungs transplanted post-EVLP (n = 42) to determine the underlying molecular mechanisms. RESULTS: Of the total 312 detected metabolites, 84 were up-regulated and 103 were down-regulated at EVLP-4h relative to 1h (FDR adjusted p < .05, fold change ≥ |1.1|). At EVLP-4h, markedly decreased energy substrates were observed, accompanied by the increase in fatty acid ß-oxidation. Concurrently, accumulation of amino acids and nucleic acids was evident, indicative of increased protein and nucleotide catabolism. The uniform decrease in free lysophospholipids and polyunsaturated fatty acids at EVLP-4h suggests cell membrane remodeling. CONCLUSIONS: Untargeted metabolomics revealed signs of energy substrate consumption and metabolic by-product accumulation under current EVLP protocols. Strategies to supplement nutrients and to maintain homeostasis will be vital in improving the current clinical practice and prolonging organ perfusion for therapeutic application to further enhance donor lung utilization.