Posterior Shoulder Instability, Part I-Diagnosis, Nonoperative Management, and Labral Repair for Posterior Shoulder Instability-An International Expert Delphi Consensus Statement.

PURPOSE: To establish consensus statements on the diagnosis, nonoperative management, and labral repair for posterior shoulder instability. METHODS: A consensus process on the treatment of posterior shoulder instability was conducted, with 71 shoulder/sports surgeons from 12 countries participating on the basis of their level of expertise in the field. Experts were assigned to 1 of 6 working groups defined by specific subtopics within posterior shoulder instability. Consensus was defined as achieving 80% to 89% agreement, whereas strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement. RESULTS: Unanimous agreement was reached on the indications for nonoperative management and labral repair, which include whether patients had primary or recurrent instability, with symptoms/functional limitations, and whether there was other underlying pathology, or patient's preference to avoid or delay surgery. In addition, there was unanimous agreement that recurrence rates can be diminished by attention to detail, appropriate indication and assessment of risk factors, recognition of abnormalities in glenohumeral morphology, careful capsulolabral debridement and reattachment, small anchors with inferior placement and multiple fixation points that create a bumper with the labrum, treatment of concomitant pathologies, and a well-defined rehabilitation protocol with strict postoperative immobilization. CONCLUSIONS: The study group achieved strong or unanimous consensus on 63% of statements related to the diagnosis, nonoperative treatment, and labrum repair for posterior shoulder instability. The statements that achieved unanimous consensus were the relative indications for nonoperative management, and the relative indications for labral repair, as well as the steps to minimize complications for labral repair. There was no consensus on whether an arthrogram is needed when performing advanced imaging, the role of corticosteroids/orthobiologics in nonoperative management, whether a posteroinferior portal is required. LEVEL OF EVIDENCE: Level V, expert opinion.

Posterior Shoulder Instability Part II - Glenoid Bone-Grafting, Glenoid Osteotomy, and Rehabilitation/Return to Play - An International Expert Delphi Consensus Statement.

PURPOSE: The purpose of this study was to establish consensus statements on glenoid bone-grafting, glenoid osteotomy, rehabilitation, return to play, and follow-up for posterior shoulder instability. METHODS: A consensus process on the treatment of posterior shoulder instability was conducted, with 71 shoulder/sports surgeons from 12 countries participating based on their level of expertise in the field. Experts were assigned to one of 6 working groups defined by specific subtopics within posterior shoulder instability. Consensus was defined as achieving 80-89% agreement, whereas strong consensus was defined as 90-99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement. RESULTS: All of the statements relating to rehabilitation, return to play, and follow-up achieved consensus. There was unanimous consensus that the following criteria should be considered: restoration of strength, range of motion, proprioception, and sport-specific skills, with a lack of symptoms. There is no minimum time point required to return to play. Collision athletes and military athletes may take longer to return because of their higher risk for recurrent instability, and more caution should be exercised in clearing them to return to play, with elite athletes potentially having different considerations in returning to play. The relative indications for revision surgery are symptomatic apprehension, multiple recurrent instability episodes, further intra-articular pathologies, hardware failure, and pain. CONCLUSION: The study group achieved strong or unanimous consensus on 59% of statements. Unanimous consensus was reached regarding the criteria for return to play, collision/elite athletes having different considerations in return to play, indications for revision surgery, and imaging only required as routine for those with glenoid bone-grafting/osteotomies at subsequent follow-ups. There was no consensus on optimal fixation method for a glenoid bone-block, the relative indications for glenoid osteotomy, whether fluoroscopy is required or if the labrum should be concomitantly repaired. LEVEL OF EVIDENCE: Level V Expert Opinion.

Reaching Minimal Clinically Important Difference, Substantial Clinical Benefit, and Patient-Acceptable Symptomatic State for Patient-Reported Outcome Measures following Arthroscopic Rotator Cuff Repair Does Not Correlate with Patient Satisfaction.

Purpose: Minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) serve as metrics to gauge orthopedic treatment efficacy based on anchoring questions that do not account for a patient's satisfaction with their surgical outcome. This study evaluates if reaching MCID, SCB, or PASS values for American Shoulder and Elbow Surgeons score (ASES), Single Alpha Numeric Evaluation (SANE), Simple Shoulder Test (SST), and Visual Analog Score (VAS) for pain following arthroscopic rotator cuff repair (RCR) correlates with overall patient satisfaction. Methods: This was a single-institution, retrospective study of patients who underwent RCR from 2015 to 2019. Pre-operative and 2 year postoperative ASES, SANE, SST, and VAS scores were recorded. Patients underwent a survey to assess: (1) what is your overall satisfaction with your surgical outcome? (scale 1 to 10); (2) if you could go back in time, would you undergo this operation again? (yes/no); (3) for the same condition, would you recommend this operation to a friend or family member? (yes/no). Spearman correlation coefficients were run to assess relationship between reaching MCID, SCB, or PASS and satisfaction. Results: Ninety-two patients were included. Mean preoperative ASES was 51.1 ± 16.9, SANE was 43.3 ± 20.9, SST was 5.4 ± 2.9, and VAS was 4.6 ± 2.1. Mean 2 year ASES was 83.9 ± 18.5, SANE was 81.7 ± 27.0, SST was 9.8 ± 3.2, and VAS was 1.4 ± 1.9. Mean patient satisfaction was 9.0 ± 1.9; 89 (96.7%) patients would undergo surgery again and recommend surgery. Correlation for reaching PASS for SANE and satisfaction was moderate. Correlation coefficients were very weak for all other outcome metrics. Conclusions: Reaching MCID, SCB, and PASS in ASES, SANE, SST, or VAS following RCR did not correlate with a patient's overall satisfaction or willingness to undergo surgery again or recommend surgery. Further investigation into the statistical credibility and overall clinical value of MCID, SCB, and PASS is necessary.

Following Anterior Cruciate Ligament Reconstruction With Bone-Patellar Tendon-Bone Autograft, the Incidence of Anterior Knee Pain Ranges From 5.4% to 48.4% and the Incidence of Kneeling Pain Ranges From 4.0% to 75.6%: A Systematic Review of Level I Studies.

Purpose: To (1) perform a systematic review of level I randomized controlled trials (RCTs) detailing the incidence of anterior knee pain and kneeling pain following anterior cruciate ligament reconstruction (ACLR) with bone-patellar tendon-bone (BPTB) autograft and (2) investigate the effect of bone grafting the patellar harvest site on anterior knee and kneeling pain. Methods: A systematic review of level I studies from 1980 to 2023 was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The primary outcome evaluated was the presence of donor site morbidity in the form of anterior knee pain or kneeling pain. A secondary subanalysis was performed to assess for differences in the incidence of postoperative pain between patient groups undergoing ACLR with BPTB receiving harvest site bone grafting and those in whom the defect was left untreated. Results: Following full-text review, 15 studies reporting on a total of 696 patients met final inclusion criteria. Patients were followed for an average of 4.78 years (range, 2.0-15.3), and the mean age ranged from 21.7 to 38 years old. The incidence of anterior knee pain, calculated from 354 patients across 10 studies, ranged from 5.4% to 48.4%. The incidence of postoperative pain with kneeling was determined to range from 4.0% to 75.6% in 490 patients from 9 studies. Patients treated with bone grafting of the BPTB harvest site had no significant difference in incidence of any knee pain compared with those who were not grafted, with incidences of 43.3% and 40.2%, respectively. Conclusions: Based on the current level I RCT data, the incidences of anterior knee pain and kneeling pain following ACLR with BPTB autograft range from 5.4% to 48.4% and 4.0% to 75.6%, respectively. Level of Evidence: Level I, systematic review of RCTs.

Editorial Commentary: Evaluation for Cartilage Lesions on Magnetic Resonance Imaging Continues to Improve: Artificial Intelligence Applications May Result in Higher Sensitivity and Specificity.

Accurate detection of cartilage lesions of the knee is required to offer patient-specific care and can alter surgical intervention options. To date, diagnostic arthroscopy remains the gold standard yet often requires the need for staged operative procedure for treatment. Magnetic resonance imaging (MRI) is the most accurate imaging modality with high specificity, yet even with recent advances, MRI has limited specificity. Newer scanners (3 T) and updated scanning sequences (3-dimensional MRI and quantitative MRI) are most sensitive in characterizing cartilage lesions of the knee, but these resources are not available to all users. Promising new avenues for patient-specific MRI scans along with the utilization of artificial intelligence will more accurately identify and quantify lesion size, location, and depth.

Anterior Cruciate Ligament Reconstruction: Fixation Techniques.

Anterior cruciate ligament reconstruction (ACLR) is among the most common procedures performed by orthopaedic sports medicine surgeons and has inherent challenges due to the complex anatomy and biomechanical properties required to reproduce the function and stability of the native ACL. Awareness of the anatomic and biomechanical factors, including graft selection and tunnel placement, along with graft tensioning and fixation techniques, is vital in achieving a successful clinical outcome. Common techniques for ACLR graft fixation include intratunnel fixation with interference screws, suspensory fixation, or hybrid fixation strategies, along with several supplemental fixation techniques. Interference screw fixation may decrease graft-tunnel motion, tunnel widening, and graft creep and may be performed with metallic, PEEK (polyether ether ketone), or bioabsorbable screws. Suspensory fixation techniques primarily include suture-buttons, anchors, staples, and screws/washers. Suspensory fixation allows adequate biomechanical strength, although some techniques have been linked to increased graft-tunnel motion and potential tunnel widening. Supplemental fixation techniques may be performed in the setting of concerns for adequacy of primary fixation and includes the use of suture anchors, staples, and screw/washer devices. Regardless of the implant chosen for fixation, secure fixation is paramount to avoid displacement of the graft and allow for integration into the bone tunnel and facilitates early postoperative rehabilitation. It is important for orthopaedic sports medicine surgeons performing primary and revision ACLR to be familiar with multiple fixation techniques.

Acute Anterior Cruciate Ligament Reconstruction Performed Within 10 Days of Injury Does Not Increase Risk of Postoperative Arthrofibrosis: A Systematic Review and Meta-analysis.

BACKGROUND: The optimal timing of anterior cruciate ligament (ACL) reconstruction (ACLR) remains a controversial topic. Previous reviews have demonstrated that there are no differences between early and delayed ACLR; however, these studies have been limited by heterogeneous definitions of acute ACL injury. PURPOSE: To evaluate postoperative patient functional outcomes and risk for arthrofibrosis after acute arthroscopic ACLR performed ≤10 days after injury. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using multiple medical databases. Inclusion criteria were studies that evaluated postoperative range of motion outcomes for patients undergoing ACLR ≤10 days after initial ACL injury. For included comparative studies comparing patient groups undergoing ACLR ≤10 days and patients undergoing "delayed" ACLR after ≥3 weeks of initial injury, quantitative analysis was performed to assess for differences in postoperative arthrofibrosis, reoperation rates, and patient-reported outcomes between groups. DerSimonian-Laird binary random-effects models were constructed to quantitatively describe the association between the ACLR time period and patient outcomes by generating effect estimates in the form of odds ratios with 95% CIs. Qualitative analysis was performed to describe variably reported patient outcomes and the risk of arthrofibrosis after ACLR for noncomparative studies. RESULTS: Screening yielded 6 full-text articles with 448 patients who underwent ACLR (296 ACLR <10 days, 152 ACLR >3 weeks), with a pooled mean age of 28.1 years. For studies amenable to quantitative analysis, there were no significant differences between ACLR performed ≤10 days and ACLR performed at the 3-week point or after in terms of postoperative stiffness (3 studies; odds ratio, 1.27; P = .508), Tegner scores (2 studies; mean difference, -0.056; P = .155), or reoperation for stiffness (3 studies; odds ratio, 0.869; P = .462). The overall incidence of postoperative arthrofibrosis after 12 months of follow-up was 11 of 296 (3.7%) for ACLRs performed ≤10 days versus 6 of 152 (3.9%) for those performed at the 3-week point or after. CONCLUSION: ACLR performed ≤10 days after the inciting injury does not increase the risk of postoperative arthrofibrosis and demonstrates similar patient-reported outcomes compared with ACLR performed at the 3-week point or after.

Nanostructure of Locally Concentrated Ionic Liquids in the Bulk and at Graphite and Gold Electrodes.

The physical properties of ionic liquids (ILs) have led to intense research interest, but for many applications, high viscosity is problematic. Mixing the IL with a diluent that lowers viscosity offers a solution if the favorable IL physical properties are not compromised. Here we show that mixing an IL or IL electrolyte (ILE, an IL with dissolved metal ions) with a nonsolvating fluorous diluent produces a low viscosity mixture in which the local ion arrangements, and therefore key physical properties, are retained or enhanced. The locally concentrated ionic liquids (LCILs) examined are 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (HMIM TFSI), 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate (HMIM FAP), or 1-butyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate (BMIM FAP) mixed with 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether (TFTFE) at 2:1, 1:1, and 1:2 (w/w) IL:TFTFE, as well as the locally concentrated ILEs (LCILEs) formed from 2:1 (w/w) HMIM TFSI-TFTFE with 0.25, 0.5, and 0.75 m lithium bis(trifluoromethylsulfonyl)imide (LiTFSI). Rheology and conductivity measurements reveal that the added TFTFE significantly reduces viscosity and increases ionic conductivity, and cyclic voltammetry (CV) reveals minimal reductions in electrochemical windows on gold and carbon electrodes. This is explained by the small- and wide-angle X-ray scattering (S/WAXS) and atomic force microscopy (AFM) data, which show that the local ion nanostructures are largely retained in LCILs and LCILEs in bulk and at gold and graphite electrodes for all potentials investigated.

The COVID-19 Pandemic Increased the Use of Virtual Fellowship Interviews, Reduced Case Volume, and Limited Sideline Coverage Opportunities During Sports Medicine Surgeon Training.

As one-year orthopaedic sports medicine fellowships rely heavily on elective cases and sports coverage, the COVID-19 pandemic necessitated fellowship programs to temporarily transition to virtual mediums for fellow education. Early in the pandemic, there was uncertainty as to how programs would address concerns of trainee readiness, adequate education, and accompanying psychological impact. However, with a return to prepandemic elective procedure volumes and sideline sports coverage responsibilities, sports medicine fellowships have regained some of their traditional education opportunities. Moreover, the implementation of novel training resources, including virtual didactics, augmented reality surgical skills labs, and telehealth medicine training are poised to outlast the current public health crisis and further supplement fellowship education. This article seeks to report on current evidence-based strategies and developments across several critical aspects of sports medicine training during the COVID-19 pandemic.

A cage-specific hydrate equilibrium model for robust predictions of industrially-relevant mixtures.

Understanding the thermophysical properties and phase behaviour of gas hydrates is essential for industrial applications ranging from energy transport and storage, CO2 capture and sequestration, to gas production from hydrates found on the seabed. Current tools for predicting hydrate equilibrium boundaries typically use van der Waals-Platteeuw-type models which are over-parameterised containing terms with limited physical basis. Here we present a new model for hydrate equilibrium calculations with 40% fewer parameters than existing tools but with equivalent accuracy, including for multicomponent gas mixtures and/or systems with thermodynamic inhibitors. By eliminating multi-layered shells from the model's conceptual basis and focusing on Kihara potential parameters for guest-water interactions specific to each hydrate cavity type, this new model provides insight into the physical chemistry governing hydrate thermodynamics. The model retains the improved description of the empty lattice developed recently by Hielscher et al. but couples the hydrate model with a Cubic-Plus-Association Equation of State (CPA-EOS) to describe fluid mixtures with many more components including inhibitors such as methanol and mono-ethylene glycol used by industry. An extensive database of over 4000 data points was used to train and evaluate the new model and compare its performance against existing tools. The absolute average deviation in temperature (AADT) achieved with the new model is 0.92 K for multicomponent gas mixtures, compared with 1.00 K for the widely-known model of Ballard and Sloan, and 0.86 K for the CPA-hydrates model implemented in the MultiFlash 7.0 software package. With fewer, more physically justified parameters, this new cage-specific model provides a robust basis for improved hydrate equilibrium predictions particularly for industrially-important, multi-component mixtures containing thermodynamic inhibitors.

Perioperative Gabapentin May Reduce Opioid Requirement for Early Postoperative Pain in Patients Undergoing Anterior Cruciate Ligament Reconstruction: A Systematic Review of Randomized Controlled Trials.

PURPOSE: To evaluate the efficacy of perioperative gabapentin or pregabalin treatment on postoperative pain and opioid requirement reduction in patients undergoing anterior cruciate ligament reconstruction (ACLR). METHODS: A systematic review of randomized control trials was conducted evaluating the effect of gabapentin or pregabalin on postoperative pain and opioid requirement for patients undergoing ACLR. The primary outcomes assessed were postoperative pain scores and opioid requirements. Secondary outcomes were complications, side effects, dosage, and timing of intervention. RESULTS: The initial search query identified 151 studies and 6 studies were included after full-text articles were reviewed. Three studies investigated the use of gabapentin and three studies investigated pregabalin. All three gabapentin studies reported significantly decreased or equivalent pain scores while also significantly reducing or removing total opioid consumption compared to control groups. Pregabalin demonstrated inconsistent efficacy for pain control and opioid consumption parameters across three studies. One study (pregabalin, n = 1) reported significantly increased incidence of dizziness with pregabalin compared to placebo. CONCLUSIONS: There is moderate evidence demonstrating that preoperative gabapentin may be safe and effective in reducing postoperative pain and opioid consumption after ACLR. Gabapentin may be considered when employed as part of a multimodal analgesia regimen; however, the optimal protocol has yet to be determined. Currently, there is limited evidence demonstrating the efficacy of pregabalin on pain and opioid consumption in the setting of ACLR. LEVEL OF EVIDENCE: Level I, systematic review of Level I Studies.

Preclinical Use of FGF-18 Augmentation for Improving Cartilage Healing Following Surgical Repair: A Systematic Review.

OBJECTIVE: To evaluate the efficacy of fibroblast growth factor-18 (FGF-18) augmentation for improving articular cartilage healing following surgical repair in preclinical (in vivo) animal models. DESIGN: A systematic review was performed evaluating the efficacy of FGF-18 augmentation with cartilage surgery compared with cartilage surgery without FGF-18 augmentation in living animal models. Eligible intervention groups were FGF-18 treatment in conjunction with orthopedic procedures, including microfracture, osteochondral auto/allograft transplantation, and cellular-based repair. Outcome variables were: International Cartilage Repair Society (ICRS) score, modified O'Driscoll histology score, tissue infill score, qualitative histology, and adverse events. Descriptive statistics were recorded and summarized for each included study. RESULTS: In total, 493 studies were identified and 4 studies were included in the final analysis. All studies were randomized controlled trials evaluating in vivo use of recombinant human FGF-18 (rhFGF-18). Animal models included ovine (n = 3) and equine (n = 1), with rhFGF-18 use following microfracture (n = 3) or osteochondral defect repair (n = 1). The rhFGF-18 was delivered via intra-articular injection (n = 2), collagen membrane scaffold (n = 1), or both (n = 1). All studies reported significant, positive improvements in cartilage defect repair with rhFGF-18 compared with controls based on ICRS score (n = 4), modified O'Driscoll score (n = 4), tissue infill (n = 3), and expression of collagen type II (n = 4) (P < 0.05). No adverse events were reported with the intra-articular administration of this growth factor, indicating short-term safety and efficacy of rhFGF-18 in vivo. CONCLUSION: This systematic review provides evidence that rhFGF-18 significantly improves cartilage healing at 6 months postoperatively following microfracture or osteochondral defect repair in preclinical randomized controlled trials.

Superior Capsule Reconstruction Using Acellular Dermal Allograft Secured at 45° of Glenohumeral Abduction Improves the Superior Stability of the Glenohumeral Joint in Irreparable Massive Posterosuperior Rotator Cuff Tears.

PURPOSE: The purpose of the current study was to create a dynamic cadaveric shoulder model to determine the effect of graft fixation angle on shoulder biomechanics following SCR and to assess which commonly used fixation angle (30° vs 45° of abduction) results in superior glenohumeral biomechanics. METHODS: Twelve fresh-frozen cadaveric shoulders were evaluated using a dynamic shoulder testing system. Humeral head translation, subacromial and glenohumeral contact pressures were compared among 4 conditions: 1) Intact, 2) Irreparable supra- and infraspinatus tendon tear, 3) SCR using acellular dermal allograft (ADA) fixation at 30° of abduction, and 4) SCR with ADA fixation at 45° of abduction. RESULTS: SCR at both 30° (0.287 mm, CI: -0.480 - 1.05 mm; P < .0001) and 45° (0.528 mm, CI: -0.239-1.305 mm; P = .0006) significantly decreased superior translation compared to the irreparably torn state. No significant changes in subacromial peak contact pressure were observed between any states. The average glenohumeral contact pressure increased significantly following creation of an irreparable RCT (373 kPa, CI: 304-443 vs 283 kPa, CI 214-352; P = .0147). The SCR performed at 45° (295 kPa, CI: 226-365, P = .0394) of abduction significantly decreased the average glenohumeral contact pressure compared to the RCT state. There was no statistically significant difference between the average glenohumeral contact pressure of the intact state and SCR at 30° and 45°. CONCLUSION: SCR improved the superior stability of the glenohumeral joint when the graft was secured at 30° or 45° of glenohumeral abduction. Fixation at 45° of glenohumeral abduction provided more stability than did fixation at 30°. CLINICAL RELEVANCE: Grafts attached at 45° of glenohumeral abduction biomechanically restore the glenohumeral stability after SCR using ADA better than fixation at 30° of glenohumeral abduction.

Impact of the COVID-19 Pandemic on Sports Medicine Patient Care.

The COVID-19 pandemic has necessitated new practices in sports medicine patient care. Telehealth has been validated as a reliable tool for consultations and physical examinations and increases access to care in a cost-efficient manner. Social distancing and avoiding team members who have tested positive are the most effective ways to reduce spread. For screening, daily self-reported symptom checklists and fever monitoring help identify potentially infected athletes who should be instructed to isolate and seek care. Polymerase chain-reaction (PCR) testing for the virus via nasopharyngeal swab is not recommended for screening and should be reserved for symptomatic individuals with fever, cough, or shortness of breath. Face masks and personal protective equipment (PPE) may be beneficial in high-risk settings, but there is little evidence to support use in athletic populations. Median return to play after COVID-19 in elite athletes has been reported as 18 days (range: 12 to 30), with 27% not fully available at 28 days. Chest pain at diagnosis was the only symptom associated with time loss longer than 28 days. Finally, canceled competitions or time loss results in grief, stress, and frustration for athletes, as well as loss of a social support network and routine training regimens. Mental health support services may be indicated.

Biomechanical comparison of anterior cruciate ligament reconstruction fixation methods and implications on clinical outcomes.

Anterior cruciate ligament reconstruction (ACLR) is one of the more common surgeries encountered by orthopaedic surgeons, which has its inherent challenges due to the complex anatomy and biomechanical properties required to reproduce the function and stability of the native ACL. Multiple biomechanical factors from graft choice and tunnel placement to graft tensioning and fixation methods are vital in achieving a successful clinical outcome. Common methods of ACLR graft fixation in both the primary and revision setting are classified into compression/interference, suspensory, or hybrid fixation strategies with multiple adjunct methods of fixation. The individual biomechanical properties of these implants are crucial in facilitating early post-operative rehabilitation, while also withstanding the shear and tensile forces to avoid displacement and early graft failure during graft osseointegration. Implants within these categories include the use of interference screws (IFSs), as well as suspensory fixation with a button, posts, surgical staples, or suture anchors. Outcomes of comparative studies across the various fixation types demonstrate that compression fixation can decrease graft-tunnel motion, tunnel widening, and graft creep, at the risk of damage to the graft by IFSs and graft slippage. Suspensory fixation allows for a minimally invasive approach while allowing similar cortical apposition and biomechanical strength when compared to compression fixation. However, suspensory fixation is criticized for the risk of tunnel widening and increased graft-tunnel motion. Several adjunct fixation methods, including the use of posts, suture-anchors, and staples, offer biomechanical advantages over compression or suspensory fixation methods alone, through a second form of fixation in a second plane of motion. Regardless of the method or implant chosen for fixation, technically secure fixation is paramount to avoid displacement of the graft and allow for appropriate integration of the graft into the bone tunnel. While no single fixation technique has been established as the gold standard, a thorough understanding of the biomechanical advantages and disadvantages of each fixation method can be used to determine the optimal ACLR fixation method through an individualized patient approach.

Return to Sport Rates and Subjective Outcomes Are Similar After Open or Endoscopically Assisted Compartment Release for Chronic Lower-Extremity Exertional Compartment Syndrome.

Purpose: To retrospectively compare return to sport rates and subjective outcomes of patients who underwent open or endoscopic compartment release for the surgical management of chronic exertional compartment syndrome. Methods: This was a retrospective review of patients who underwent lower-extremity fasciotomy for chronic exertional compartment syndrome from June 2012 to June 2020. Eligibility included patients 15 to 45 years of age who identified as an athlete and had at least 6 months of follow-up. Fasciotomies for trauma or infection were excluded. One surgeon exclusively performed each type of surgery. Postoperative outcome measures included the Lower Extremity Functional Scale, the Marx Activity Scale, and a return to play survey. Results: In total, 24 patients (13 endoscopically assisted fasciotomies, 11 open fasciotomies) had a mean follow-up of 3.8 ± 2.1 years; 19 patients returned to their sporting activity. No significant difference existed between return to play rates (P = .630) or return to play times (P = .351). There were no significant differences between the groups in the Lower Extremity Functional Scale score, Marx Activity Scale score, Single Assessment Numeric Evaluation score, pain score at rest, and during sporting activity. Overall satisfaction rates were found to be significantly greater in the endoscopically assisted fasciotomy group (P = .041). Conclusions: In this small sample of heterogenous groups of patients, we found no significant differences in return to sport rates or subjective results after surgery. Patients experienced a high subjective recurrence rate. The endoscopically assisted fasciotomy group reported greater subjective patient satisfaction compared with the open fasciotomy group. Level of Evidence: Level III, comparative study, retrospective.

Surface-Enhanced Raman Scattering Imaging of Cetylpyridinium Chloride Adsorption to a Solid Surface.

Surface active agents (surfactants) have found a variety of critical technological applications, from helping infant lungs breathe to fugitive dust control at industrial sites. Surfactant molecules adsorb to an interface and facilitate a decrease in the surface free energy (interfacial tension) between two immiscible phases. However, a limited number of methods (e.g., holography and fluorescence microscopy) achieved visualization of surfactant molecule distribution in multiphase systems qualitatively. To probe the efficacy and/or adsorption density of surfactants at such interfaces quantitatively, we demonstrate here a direct observation of surfactant adsorption by surface-enhanced Raman scattering (SERS). This work details the development of a research platform to study surfactant adsorption using Raman imaging. The imaging and analysis were successfully benchmarked against conventional interfacial tension measurements and thermodynamic theory employed to estimate surfactant adsorption at equilibrium. This in situ Raman-based experimental method provides a platform to interrogate structure-function relationships that inform the design process for new surfactant species.

Clinical and Patient-Reported Outcomes for Acute Acromioclavicular Joint Fixation are Similar With or Without Allograft Augmentation.

Purpose: To compare functional outcomes, complications, and revision rates between allograft reconstruction and graftless fixation techniques for the treatment of Rockwood grades III-V acute acromioclavicular (AC) joint separation. Methods: Patients who underwent graftless or allograft surgery acutely (≤6 weeks from injury) for Rockwood type III-V AC joint separations from 2012 to 2018 were retrospectively reviewed. Clinic notes and operative reports were identified to confirm the surgical technique and presence of complications including revision, infection, and fracture. In addition, postoperative radiographs were assessed to determine any instances of loss of adequate reduction, and several patient-reported outcomes were collected. Results: In total, 115 patients (52 allograft, 63 graftless) were included in this study with a mean follow-up of 3.8 ± 2.5 years. There were no differences between allograft and graftless patients regarding rates of loss of reduction >5 mm (11.1% graftless vs 21.2% allograft), revision (3.2% vs 1.9%), infection (1.6% vs 3.9%), fracture (3.2% vs 7.7%), or total complication (7.9% vs 9.6%) rates (all P > .05). Patient-reported outcome measures also did not significantly differ between groups. Multivariate analysis found that increased time from injury to repair and increased Rockwood injury grade (grades IV and V) were associated with increased CC distance at postoperative follow-up (P = .008, .050, and .047, respectively). Conclusion: Multivariate analysis found that patients who underwent acute AC joint fixation without allograft augmentation had similar functional outcomes, complications, and revision rates compared with patients who underwent AC joint reconstruction with allograft. Level of Evidence: Level III, retrospective comparative study.

Qualitative and Quantitative Anatomic Descriptions of the Coracoclavicular and Acromioclavicular Ligaments: A Systematic Review.

Purpose: To summarize the quantitative and qualitative anatomy of the acromioclavicular (AC) and coracoclavicular (CC) ligaments of the AC joint. Methods: A systematic review of the literature evaluating the quantitative and qualitative anatomy of the CC and AC ligaments of the AC joint was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Results: The conoid ligament (CL) arises from the posterior coracoid precipice and courses with a tapered inferior apex to insert on the conoid tubercle of the posteroinferior clavicle. The trapezoid ligament originates from the anterior-superior coracoid with medially extending fibers anterior to the conoid's C-shaped footprint and runs with the CL to insert along the trapezoid line on the inferior aspect of the anterior clavicle, anterolateral to the conoid tubercle. The AC capsule's superoposterior bundle and the CL are robust stabilizing ligaments characterized by prominent attachment sites to the posteroinferior clavicle. Conclusions: Clear and consistent quantitative and qualitative descriptions of the CC ligaments (CL and trapezoid ligament) have been well defined; however, quantitative data on the capsuloligamentous anatomy of AC ligaments (superoposterior and anteroinferior) ligaments) remain limited. Clinical Relevance: There are high complication and failure rates after AC joint stabilization. To improve patient outcomes, the anatomy of the CC and AC joints needs to be better understood.