Axon-like active signal transmission.

Any electrical signal propagating in a metallic conductor loses amplitude due to the natural resistance of the metal. Compensating for such losses presently requires repeatedly breaking the conductor and interposing amplifiers that consume and regenerate the signal. This century-old primitive severely constrains the design and performance of modern interconnect-dense chips1. Here we present a fundamentally different primitive based on semi-stable edge of chaos (EOC)2,3, a long-theorized but experimentally elusive regime that underlies active (self-amplifying) transmission in biological axons4,5. By electrically accessing the spin crossover in LaCoO3, we isolate semi-stable EOC, characterized by small-signal negative resistance and amplification of perturbations6,7. In a metallic line atop a medium biased at EOC, a signal input at one end exits the other end amplified, without passing through a separate amplifying component. While superficially resembling superconductivity, active transmission offers controllably amplified time-varying small-signal propagation at normal temperature and pressure, but requires an electrically energized EOC medium. Operando thermal mapping reveals the mechanism of amplification-bias energy of the EOC medium, instead of fully dissipating as heat, is partly used to amplify signals in the metallic line, thereby enabling spatially continuous active transmission, which could transform the design and performance of complex electronic chips.

Xiphoid nucleus of the midline thalamus controls cold-induced food seeking.

Maintaining body temperature is calorically expensive for endothermic animals1. Mammals eat more in the cold to compensate for energy expenditure2, but the neural mechanism underlying this coupling is not well understood. Through behavioural and metabolic analyses, we found that mice dynamically switch between energy-conservation and food-seeking states in the cold, the latter of which are primarily driven by energy expenditure rather than the sensation of cold. To identify the neural mechanisms underlying cold-induced food seeking, we used whole-brain c-Fos mapping and found that the xiphoid (Xi), a small nucleus in the midline thalamus, was selectively activated by prolonged cold associated with elevated energy expenditure but not with acute cold exposure. In vivo calcium imaging showed that Xi activity correlates with food-seeking episodes under cold conditions. Using activity-dependent viral strategies, we found that optogenetic and chemogenetic stimulation of cold-activated Xi neurons selectively recapitulated food seeking under cold conditions whereas their inhibition suppressed it. Mechanistically, Xi encodes a context-dependent valence switch that promotes food-seeking behaviours under cold but not warm conditions. Furthermore, these behaviours are mediated by a Xi-to-nucleus accumbens projection. Our results establish Xi as a key region in the control of cold-induced feeding, which is an important mechanism in the maintenance of energy homeostasis in endothermic animals.

Design, Synthesis, and In Vitro and In Vivo Evaluation of Cereblon Binding Bruton's Tyrosine Kinase (BTK) Degrader CD79b Targeted Antibody-Drug Conjugates.

Antibody-drug conjugates (ADCs) are an established modality that allow for targeted delivery of a potent molecule, or payload, to a desired site of action. ADCs, wherein the payload is a targeted protein degrader, are an emerging area in the field. Herein we describe our efforts of delivering a Bruton's tyrosine kinase (BTK) bifunctional degrader 1 via a CD79b mAb (monoclonal antibody) where the degrader is linked at the ligase binding portion of the payload via a cleavable linker to the mAb. The resulting CD79b ADCs, 3 and 4, exhibit in vitro degradation and cytotoxicity comparable with that of 1, and ADC 3 can achieve more sustained in vivo degradation than intravenously administered 1 with markedly reduced systemic exposure of the payload.

Is hip capsule morphology associated with hip pain in patients without another structural correlate?

OBJECTIVE: The goals of this study were (i) to assess the association between hip capsule morphology and pain in patients without any other MRI abnormalities that would correlate with pain and (ii) to investigate whether hip capsule morphology in hip pain patients is different from that of controls. METHODS: In this study, 76 adults with hip pain who did not show any structural abnormalities on MRI and 46 asymptomatic volunteers were included. Manual segmentation of the anterior and posterior hip capsules was performed. Total and mean anterior hip capsule area, posterior capsule area, anterior-to-posterior capsule area ratio, and medial-to-lateral area ratio in the anterior capsule were quantified. Differences between the pain and control groups were evaluated using logistic regression models. RESULTS: Patients with hip pain showed a significantly lower anterior-to-posterior area ratio as compared with the control group (p = 0.002). The pain group's posterior hip capsule area was significantly larger than that of controls (p = 0.001). Additionally, the ratio between the medial and lateral sections of the anterior capsule was significantly lower in the pain group (p = 0.004). CONCLUSIONS: Patients with hip pain are more likely to have thicker posterior capsules and a lower ratio of the anterior-to-posterior capsule area and thinner medial anterior capsules with a lower ratio of the medial-to-lateral anterior hip capsule compartment, compared with controls. CLINICAL RELEVANCE STATEMENT: During MRI evaluations of patients with hip pain, morphology of the hip capsule should be assessed. This study aims to be a foundation for future analyses to identify thresholds distinguishing normal from abnormal hip capsule measurements. KEY POINTS: • Even with modern image modalities such as MRI, one of the biggest challenges in handling hip pain patients is finding a structural link for their pain. • Hip capsule morphologies that correlated with hip pain showed a larger posterior hip capsule area and a lower anterior-to-posterior capsule area ratio, as well as a smaller medial anterior capsule area with a lower medial-to-lateral anterior hip capsule ratio. • The hip capsule morphology is correlated with hip pain in patients who do not show other morphology abnormalities in MRI and should get more attention in clinical practice.

Editorial Commentary: Prolonged Joint Effusion After Hip Arthroscopy May Be Associated With Persistent Symptoms.

Research to investigate causes for continued symptoms in patients who undergo hip arthroscopic treatment is an opportunity to improve outcomes. A disconcertingly large number of patients (47%-66%) show a joint effusion/synovitis on magnetic resonance imaging at 6 to 12 months after hip arthroscopy for femoroacetabular impingement syndrome, and a recent study shows that this is associated with inferior 2-year clinical outcomes compared to patients without effusions. Perhaps the effusions are associated with comorbid structural abnormalities such as cartilage degeneration, capsule defect, labral reinjury, adhesions, or microinstability/hyperlaxity. In theory, interventions to treat the effusion, such as intra-articular injections or anti-inflammatory medications (which also prophylax against heterotopic ossification), will produce sustained clinical improvement.

Editorial Commentary: Capsular Management During Hip Arthroscopy Is Recommended, But a Limited Capsulotomy in Male Patients May Heal Without Closure.

The hip capsule consists of the iliofemoral, ischiofemoral, and pubfemoral ligaments. The iliofemoral ligament is an important part of the anterior hip capsule that functions to stabilize the joint but is commonly incised in order to obtain access during hip arthroscopy, as described in techniques such as interportal, T, puncture, and periportal capsulotomy. For the most commonly used interportal capsulotomy, recent literature has advocated for closure of the capsule at the end of the surgery to avoid iatrogenic instability or microinstability. Systematic reviews and cohort studies have reported significantly better patient-reported outcomes after hip arthroscopy for femoroacetabular impingement syndrome with capsule closure compared to without capsule closure. However, recent high-level evidence from a randomized controlled trial demonstrated that in a predominantly male cohort there was no difference in patient-reported outcomes improvements or complications between patients undergoing hip arthroscopy for femoroacetabular impingement syndrome through an interportal capsulotomy who were randomized to receive capsule closure versus no capsule closure. Of note, male patients have inherently tighter and more stable joints than female patients and therefore are at lower risk for postoperative instability or microinstability from an interportal capsulotomy that does not properly heal. Also, if the capsule is not violated below the 3-o'clock position (for a right hip, or 9 o'clock for a left hip), there may be less risk to destabilizing the hip joint. A limited interportal capsulotomy in male patients could lead to healing in an unrepaired state.

Increasing Hip Arthroscopy Case Volume Is Associated With Increased Risk for Revision Surgery but Not Conversion to Total Hip Arthroplasty or 90-Day Hospitalizations: A Cross-Sectional Analysis of 468 Surgeons.

PURPOSE: To analyze the effects of surgeon-specific factors, including case volume, career duration, fellowship training, practice type, and region of practice, on rates of 2-year revision surgery, conversion to total hip arthroplasty (THA), and 90-day hospitalizations following hip arthroscopy. METHODS: The PearlDiver Mariner Database was used to query patients undergoing hip arthroscopy between 2015 and 2018. Surgeons performing these procedures were identified, and surgeon-specific demographics and variables were collected from publicly available data. Patients were followed for 2 years to assess for reoperations, including revision hip arthroscopy and conversion to THA, as well as 90-day hospitalizations, including emergency department visits and hospital readmissions. International Classification of Diseases, Tenth Revision codes were used to track the laterality of revision hip procedures. Associations between surgeon-specific factors and postoperative outcomes were assessed through univariate and multivariate analyses. RESULTS: In total, 20,834 patients underwent hip arthroscopy procedures by 468 surgeons. Multivariate analysis with logistic regression adjusted for patient-related factors (age, sex, obesity, Charlson Comorbidity Index, and smoking status) identified increasing surgeon case volume to be associated with increased risk for 2-year revision hip arthroscopy (P < .001), but not 2-year conversion to THA or 90-day hospitalizations. Nonsports medicine fellowship-trained surgeons were associated with greater risk for 2-year THA conversion (P < .001) and 90-day hospital readmissions (P < .01). Surgeons practicing in an academic setting demonstrated greater risk for 90-day hospital readmissions (P < .001). Surgeons practicing in the West region of the United States were more likely to incur 2-year revision hip arthroscopy procedures compared to surgeons in the South, Midwest or Northeast (P < .001). CONCLUSIONS: Increasing surgeon hip arthroscopy case volume is associated with an increased risk for 2-year revision hip arthroscopy but not conversion to THA or 90-day hospitalizations. Further, non-sports medicine fellowship-trained surgeons were associated with higher risk for 2-year THA conversion after hip arthroscopy. LEVEL OF EVIDENCE: Level III, retrospective cohort analysis.

No Differences in 2-Year Reoperation Rates for Meniscus Allograft Transplant With Concomitant Cartilage Restoration or Osteotomy: A National Database Study.

PURPOSE: To investigate reoperation rates after meniscus allograft transplant (MAT), comparing rates with and without concomitant articular cartilage and osteotomy procedures using a national insurance claims database. METHODS: We performed a retrospective cohort study of patients who underwent MAT from 2010 to 2021 with a minimum 2-year follow-up using the PearlDiver database. Using Current Procedural Terminology and International Classification of Diseases codes, we identified patients who underwent concomitant procedures including chondroplasty or microfracture, cartilage restoration defined as osteochondral graft or autologous chondrocyte implantation (ACI), or osteotomy. Univariate logistic regressions identified risk factors for reoperation. Reoperations were classified as knee arthroplasty, interventional procedures, or diagnostic or debridement procedures. RESULTS: The study included 750 patients with an average age of 29.6 years (interquartile range: 21.0-36.8) and average follow-up time was 5.41 years (SD: 2.51). Ninety-day, 2-year, and all-time reoperation rates were 1.33%, 14.4%, and 27.6%, respectively. MAT with cartilage restoration was associated with increased reoperation rate at 90 days (odds ratio: 4.88; 95% confidence interval: 1.38-19.27; P = .015); however, there was no significant difference in reoperation rates at 2 years or to the end of follow-up. ACI had increased reoperation rates at 90 days (odds ratio: 6.95; 95% confidence interval: 1.45-25.96; P = .006), with no difference in reoperation rates 2 years postoperatively or to the end of follow-up. Osteochondral autograft and allograft were not associated with increased reoperation rates. CONCLUSIONS: In our cohort, 14.4% of patients had a reoperation within 2 years of MAT. Nearly 1 in 4 patients undergoing MAT had concomitant cartilage restoration, showing that it is commonly performed on patients with articular cartilage damage. Concomitant osteochondral autograft, osteochondral allograft, chondroplasty, microfracture, and osteotomy were not associated with any significant difference in reoperation rates. ACI was associated with increased reoperation rates at 90 days, but not later. LEVEL OF EVIDENCE: Level IV, retrospective cohort study.

Preoperative Hip Injection Response Does Not Reliably Predict 2-Year Postoperative Outcomes After Hip Arthroscopy for Femoroacetabular Impingement.

PURPOSE: To determine whether response to preoperative local anesthetic or corticosteroid intra-articular injections can predict 2-year postoperative outcomes in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS). METHODS: We performed a retrospective analysis of patients undergoing hip arthroscopy for FAIS at a single institution from 2014 to 2020. Patients who underwent preoperative intra-articular hip injections were classified based on injection type (local anesthetic or corticosteroid) and whether they experienced pain relief after injection (responders or nonresponders). Responders were matched 2:1 to nonresponders by age, body mass index, and sex. Patient-reported outcomes (PROs) including the Hip Disability and Osteoarthritis Outcome Score (HOOS), 12-Item Short-Form Health Survey (SF-12) Mental Component Summary score, SF-12 Physical Component Summary score, and visual analog scale pain score were collected preoperatively and 2 years postoperatively. Mean score change and minimal clinically important difference (MCID) achievement were calculated and compared between groups. RESULTS: The matched cohort included 126 total patients (42 nonresponders and 84 responders; 74.6% female sex; age [mean ± standard deviation], 30.9 ± 9.9 years; body mass index, 24.7 ± 3.7) with no differences in demographic or radiographic hip variables. Both groups showed significant 2-year postoperative score improvements across all PROs, except the SF-12 Mental Component Summary score, which remained unchanged. There was no difference in mean score change or MCID achievement across all PROs between the corticosteroid injection responder and nonresponder groups. In the local anesthetic group, MCID achievement was similar across all PROs, except the visual analog scale pain score, which showed a greater percentage of MCID achievement among local anesthetic nonresponders (89.5%) than in responders (55.0%, P = .03). Significant ceiling effects were most readily apparent within the injection responder group, with greater percentages of patients achieving maximal 2-year postoperative survey scores (HOOS-Activities of Daily Living, 36.9%; HOOS-Pain, 19.0%; HOOS-Quality of Life, 15.5%; and HOOS-Sport, 32.1%). CONCLUSIONS: Response to preoperative injection with either corticosteroid or local anesthetic did not predict 2-year outcomes after hip arthroscopy in patients with FAIS. LEVEL OF EVIDENCE: Level III, retrospective matched-cohort study.

Socioeconomic Factors Including Patient Income, Education Level, and Health Insurance Influence Postoperative Secondary Surgery and Hospitalization Rates Following Hip Arthroscopy.

PURPOSE: To evaluate a large cross-sectional sample of patients utilizing administrative database records and analyze the effects of income, insurance type, and education level on outcomes after hip arthroscopy, including 2-year revision surgery, conversion to total hip arthroplasty (THA), and 90-day hospitalizations. METHODS: Current Procedural Terminology codes were used to query the PearlDiver Mariner database from October 2015 to January 2020 for patients undergoing hip arthroscopy with a minimum 2-year follow-up. Patients were categorized by mean family income in their zip code of residence (MFIR), health insurance type, and educational attainment in their zip code of residence (EAR). Two-year revision arthroscopy, conversion to THA, and 90-day hospital readmissions or emergency department (ED) visits were analyzed along socioeconomic strata. RESULTS: Multivariate analysis of 33,326 patients revealed that patients with MFIR between $30,000 and $70,000 had lower odds of 2-year revision arthroscopy (odds ratio [OR], 0.63; P < .001), THA conversion (OR, 0.76; P = .050), and 90-day readmission (OR, 0.53; P = .007) compared to MFIR >$100,000. Compared to patients with commercial insurance, patients with Medicare had lower odds of revision arthroscopy (OR, 0.60; P = .035) and THA conversion (OR, 0.46, P < .001) but greater odds of 90-day readmission (OR, 1.74; P = .007). Patients with Medicaid had higher odds of 90-day ED visits (OR, 1.84; P < .001). Patients with low EAR had higher odds of revision arthroscopy (OR, 1.42; P = .005) and THA conversion (OR, 1.58; P = .002) compared to those with high EAR. CONCLUSIONS: Following hip arthroscopy, patients residing in areas with lower mean family income were less likely to undergo reoperations and readmissions. Medicare patients showed lower reoperation but higher readmission odds, while Medicaid patients showed higher odds of ED visits. Additionally, higher educational attainment in the zip code of residence is protective against future reoperation. LEVEL OF EVIDENCE: Level III, retrospective case series.

Concomitant Medial Collateral Ligament Injury Increases the Risk of Revision Anterior Cruciate Ligament Reconstruction.

PURPOSE: To compare rates of revisions between patients with isolated anterior cruciate ligament (ACL) reconstruction and those who had concomitant medial collateral ligament (MCL) injuries managed either operatively or nonoperatively at the time of index anterior cruciate ligament reconstruction (ACLR). METHODS: Using laterality-specific International Classification of Diseases, Tenth Revision (ICD-10) and Current Procedural Terminology (CPT) codes, we queried the PearlDiver-Mariner Database for all patients who underwent ACLR between 2016 and 2020. Patients were included if they were ages 15 or older and had a minimum of 2 years of follow-up after index ACLR. Patients were then divided into cohorts by presence or absence of concomitant MCL injury. The cohort of concomitant MCL injuries was further subdivided into those with MCL injuries managed nonoperatively, with MCL repair, or with MCL reconstruction at the time of index ACLR. Multivariate regression was performed between cohorts to evaluate for factors associated with revision ACLR. RESULTS: We identified 47,306 patients with isolated ACL injuries and 10,846 with concomitant MCL and ACL injuries. In total, 93% of patients with concomitant MCL injuries had their MCL treated nonoperatively; however, the annual proportion of patients being surgically managed for their MCL injury increased by 70% from 2016 to 2020. Concomitant MCL injury patients had greater odds of undergoing revision ACLR compared with patients with isolated ACL injuries (odds ratio 1.50, 95% confidence interval 1.36-1.66, P < .001). Among patients with concomitant MCL injuries, surgically managed patients had a greater risk of revision ACLR compared with nonoperatively managed MCL injuries (odds ratio 1.39, 95% confidence interval 1.01-1.86, P = .034). CONCLUSIONS: Despite an increase in operatively managed concomitant MCL injuries, most concomitant MCL injuries were still managed nonoperatively at the time of ACLR. Patients with concomitant MCL injuries, particularly those managed operatively, at the time of ACLR are at increased risk of requiring revision ACLR compared with those with isolated ACL injuries. LEVEL OF EVIDENCE: Level III, retrospective comparative case series.

Low Volume and Early Career Surgeons have Higher Risk for Reoperation and Complications following Anterior Cruciate Ligament Reconstruction.

PURPOSE: The purpose of this study was to characterize the population of surgeons performing ACLRs in the United States and investigate the relationships between surgeon volume, career duration, and practice setting on surgical outcomes. METHODS: A large nationwide insurance database was queried for patients undergoing primary ACLR. Provider gender, degree type (allopathic vs. osteopathic), practice setting (academic versus private as defined by ACGME affiliation), surgeon volume per year, and career duration were obtained. Reoperations, hospitalizations, and emergency department visits were recorded. The relationships between surgeon-specific factors and postoperative outcomes were investigated through univariable and multivariable analyses controlling for patient factors such as age, gender and comorbidities. RESULTS: 54,498 patients underwent ACLR by 3,782 surgeons between 2015 and 2019 with a minimum 2-year follow up. 97.2% of the surgeons were male and 90.9% had an allopathic degree. Multivariate analysis controlling for patient variables including age, gender and comorbidities revealed surgeons with low yearly ACLR case volume demonstrated higher risk for revision ACLR while surgeons with high yearly case volume had lower revision ACLR rates (p = 0.02, p =0.003). Additionally, low case volume per year had higher rates of emergency department visits (p = 0.01). Early career surgeons had higher rates of both ACLR and non-ACLR arthroscopic reoperations (p < 0.001, p = 0.006) as well as increased emergency department visits (p <0.001). Academic affiliation was independently associated with greater non-ACLR reoperations (p < 0.001), emergency department visits (p = 0.007) and hospital readmissions (0.006). CONCLUSION: Patients undergoing ACLR by early career surgeons and surgeons with low yearly ACLR case volume were at increased risk for revision ACLR and post-operative ED visits.

Acetabular cartilage delamination: performance of MRI using arthroscopy as the standard of reference.

BACKGROUND: Femoroacetabular impingement (FAI) frequently leads to acetabular chondral delamination. Early identification and treatment of these cases is crucial to prevent further damage to the hip. PURPOSE: To evaluate the accuracy of morphological signs of cartilage acetabular delamination in non-arthrographic magnetic resonance imaging (MRI) using intra-articular arthroscopic findings in patients undergoing FAI surgery. MATERIAL AND METHODS: All hip MRI scans were assessed individually by three independent radiologists. Images were assessed for signs of delamination including the presence of a linear area of bright signal intensity along the acetabular subchondral bone and an area of darker tissue at the surface of the acetabular cartilage. All FAI patients underwent surgery; arthroscopy served as the standard of reference. RESULTS: The mean age of participants was 36.1±10.9 years with 36 (48.6%) women. In the FAI group, arthroscopic surgery showed acetabular chondral delamination in 37 hips. In all hips (including the controls), MRI signs of acetabular cartilage delamination showed an average sensitivity across the three raters of 73.0% with a specificity of 71.0%. In a separate analysis of only the FAI patients, a slightly higher sensitivity (77.7%) but lower specificity (66.7%) was demonstrated. The interrater reliability showed a moderate agreement (average [k]) across the raters (0.450). CONCLUSION: Performance of non-arthrographic MRI in diagnosing acetabular chondral delamination showed good results, yet inter-observer reproducibility among different radiologists was only moderate. Our results suggest that an increased level of awareness, for signs of delamination using MRI, will be helpful for detecting chondral delamination in patients with a history of FAI.

Editorial Commentary: Rates of 5-Year Secondary Surgery After Hip Arthroscopy May Be Higher Than Reported: The Highs and Lows of the Administrative Database Study.

Administrative claims databases have great power for clinical research, especially when used to evaluate trends from large cohorts. However, it should be noted that in these types of studies, patients in a database are treated at different time points, so some patients do not reach long-term follow-up by the end of the study period. Thus, such analyses require more stringent inclusion and exclusion criteria, which may significantly reduce the size of the included cohort. Recent research using the PearlDiver database has reported that the 5-year secondary surgery rate after hip arthroscopy is 4.9%. However, our research using the PearlDiver Mariner data set showed a 2-year reoperation rate after hip arthroscopy of 15%, and although most secondary surgical procedures occur within the first 2 years after hip arthroscopy, the 5-year reoperation rate may be higher. Readers should remain alert to the limitations of large database analyses.

Editorial Commentary: Hip Arthroscopy in Patients With Early Degeneration Who Receive Intra-Articular Bone Marrow Aspirate Concentrate Can Achieve Outcomes Similar to Nonarthritic Patients.

The management of patients with early joint degeneration is challenging. In this setting, biologic interventions, from platelet-rich plasma to bone marrow aspirate concentrate (BMAC) to hyaluronic acid, may be beneficial. Recent research, with 2-year follow-up, shows that patients with early degenerative changes (Tönnis grade 1 or 2) who received intra-articular injection of BMAC after hip arthroscopy procedure had improvements in outcomes similar to nonarthritic patients (Tönnis 0) with symptomatic labral tears who underwent arthroscopy and did not receive BMAC. Although confirmatory investigation using patients with early degenerative changes as a control is required, it is possible that with BMAC, patients with early degenerative changes of their hip could achieve functional outcomes similar to patients with nonarthritic hips.

Hypermobile Patients With Femoroacetabular Impingement Syndrome Can Be Effectively Treated Utilizing Hip Arthroscopy With Periportal Capsulotomy Closure: A Matched Cohort Analysis Compared to Patients Without Joint Hypermobility.

PURPOSE: To assess the 2-year outcomes of arthroscopic treatment with periportal capsulotomy closure for femoroacetabular impingement syndrome (FAIS) in patients with generalized ligamentous laxity (GLL). METHODS: A retrospective analysis was performed from a prospectively collected database of FAIS patients undergoing hip arthroscopy. FAIS patients with GLL were identified as having Beighton score ≥4. FAIS patients with GLL were treated with arthroscopic labral repair, osteochondroplasty, via periportal capsulotomy with subsequent capsular closure. These patients were matched by age, sex, and body mass index (BMI) with a cohort of FAIS patients without GLL who underwent the same procedure via periportal capsulotomy without capsular closure. Preoperatively, and 2 years postoperatively, patients completed patient-reported outcomes (PRO) scores, including the Hip Disability and Osteoarthritis Outcome Score (HOOS), 12-item Short-Form survey (SF-12) and the visual analog scale (VAS). RESULTS: Forty patients (5 male, 35 female) with FAIS and GLL were included (age: 29.7 ± 9.0; BMI: 23.3 ± 4.1). FAIS patients with GLL demonstrated similar significant PRO score improvements compared to a matched cohort of FAIS patients without GLL at 2 years after surgery (VAS Pain: (-)2.5 ± 3.0, (-)2.7 ± 2.7; SF-12 PCS: 17.7 ± 14.2, 16.7 ± 15.0; HOOS-Symptoms: 26.3 ± 24.0, 20.6 ± 18.1; HOOS-Pain: 29.8 ± 20.4, 24.4 ± 9.0; HOOS-ADL: 24.9 ± 18.4, 22.0 ± 19.9; HOOS-Sports: 43.6 ± 26.1, 33.1 ± 29.8; and HOOS-QOL: 44.2 ± 27.6, 41.7 ± 27.1, respectively). Both cohorts achieved minimal clinically important differences (MCID) for each HOOS subscore at equivalent high rates (70-88%). CONCLUSIONS: Patients with GLL in the setting of FAIS can be effectively treated with arthroscopy via periportal capsulotomy and capsular closure. These patients demonstrate significant improvements in PRO scores at 2 years, similar to normal laxity FAIS patients undergoing arthroscopic treatment via periportal capsulotomy without capsular closure. LEVEL OF EVIDENCE: Level III, retrospective comparative therapeutic trial.

Utilization of Autologous Chondrocyte Implantation in the Knee Is Increasing While Reoperation Rates Are Decreasing Despite Increasing Preoperative Comorbidities.

PURPOSE: The primary purpose of this study was to assess the use of autologous chondrocyte implantation (ACI) procedures in the knee during last decade, and the secondary aims of the study were to determine reoperation rates after ACI and to identify associated risk factors. METHODS: A retrospective cohort study from 2010-2020 was performed using the PearlDiver database. The database was queried for the Current Procedural Terminology (CPT) code for ACI performed in any knee location, including the patellofemoral and tibiofemoral joints. Reoperation was defined as interventional knee procedures or total knee arthroplasty after ACI. Reoperations were identified using CPT and International Classification of Diseases codes. Univariate and multivariate logistic regression were used to identify risk factors for reoperation. Significance was defined as P < .05. RESULTS: Among the 2010 patients included in this study, there were 90-day and overall reoperation rates of 2.24% and 30.4%, respectively, with an average follow up of 4.8 ± 3.3 years. The most common reoperations included chondroplasty, meniscectomy, and microfracture. There was an increased rate of ACI performed from 2017-2019 (5.53/100,000) compared to 2014-2016 (4.16/100,000; P < .001). ACI surgeries performed in 2017-2019 were associated with decreased risk of reoperation within 2 years relative to 2014-2016 (odds ratio [OR] = 0.70; 95% confidence interval [CI], 0.52-0.94; P = .019). In the entire ACI cohort, older age (OR = 1.07; 95% CI, 1.05-1.09; P < .001) and tobacco use (OR = 2.13; 95% CI, 1.06-3.94; P = .022) were associated with increased risk of conversion to arthroplasty. Male sex was associated with decreased overall reoperation rates (OR = 0.73; 95% CI, 0.60-0.89; P = .002). CONCLUSIONS: There has been increasing use of ACI in the knee with decreased risk of reoperation since 2017 and the introduction of matrix-associated autologous chondrocyte implantation. Older age and tobacco use were predictors of increased risk of conversion to arthroplasty. Male sex was associated with decreased risk of reoperation. LEVEL OF EVIDENCE: Level IV, retrospective cohort design; database study.

Incidence of Venous Thromboembolism After Hip Arthroscopy Is Low With or Without Prophylaxis but Risk Factors Include Oral Contraceptive Use, Obesity, and Malignancy.

PURPOSE: To determine the incidence of and risk factors for symptomatic venous thromboembolism (VTE) after hip arthroscopy (HA) and thromboprophylaxis prescription utilization for this procedure. METHODS: The PearlDiver Mariner database was queried using Current Procedural Terminology codes to identify adult patients (aged ≥ 18 years) who underwent HA between 2010 and 2020. Patient demographic information, including age, oral contraceptive use, and medical comorbidities, as well as perioperative thromboprophylaxis utilization, was recorded using International Classification of Diseases codes and National Drug Codes. The incidence of postoperative VTE within 90 days was determined. Multivariate logistic regression was used to identify predictors of perioperative thromboprophylaxis utilization and risk factors for VTE. RESULTS: The queried records identified 60,181 patients who met the inclusion criteria. Of these patients, 367 (0.6%) experienced VTE, including deep venous thrombosis (0.5%) and/or pulmonary embolism (0.2%). Approximately 2.1% of patients used thromboprophylaxis, including aspirin (1.1%), low-molecular-weight heparin (0.9%), and oral factor Xa inhibitors (0.1%). Oral contraceptive pill use (adjusted odds ratio [aOR], 2.16; 95% confidence interval [CI], 1.34-3.46), obesity (aOR, 1.37; 95% CI, 1.05-1.79), and a history of malignancy (aOR, 1.69; 95% CI, 1.12-2.54) were associated with increased odds of experiencing VTE. Perioperative thromboprophylaxis (aOR, 0.52; 95% CI, 0.19-1.39) was not significantly associated with decreased odds of experiencing VTE. However, obesity (aOR, 1.17; 95% CI, 1.00-1.38) and hypertension (aOR, 1.17; 95% CI, 1.02-1.36) were associated with increased odds of thromboprophylaxis prescription utilization. CONCLUSIONS: Although the overall risk of symptomatic VTE after HA remains low, oral contraceptive use, obesity, and a history of malignancy are associated with increased odds of thromboembolic events within 90 days. Routine thromboprophylaxis after HA may not be indicated in all patients but can be considered based on patient-specific risk factors. LEVEL OF EVIDENCE: Level III, retrospective prognostic comparative trial.

Pre-existing Mental Health Diagnoses Are Associated With Higher Rates of Postoperative Complications, Readmissions, and Reoperations Following Arthroscopic Rotator Cuff Repair.

PURPOSE: To investigate the association between preoperative mental health disorders and postoperative complications, readmissions, and ipsilateral revision procedures among patients undergoing arthroscopic rotator cuff repair (RCR). METHODS: A retrospective cohort study from 2010 to 2020 was performed using the PearlDiver database. Current Procedural Terminology and International Classification of Diseases codes were used to compare patients with and without mental health disorders who underwent arthroscopic RCR. Mental health disorders evaluated in this study include depressive disorder, major depressive disorder, major depressive affective disorder, bipolar disorder, dysthymic disorder, adjustment disorder, separation anxiety disorder, and posttraumatic stress disorder. Patients were matched at a 1:1 ratio based on age, sex, Charlson Comorbidity Index, body mass index, and tobacco use. Rates of complications and subsequent surgeries were compared between patients with and without a preoperative diagnosis of a mental health disorder. RESULTS: The 1-year preoperative prevalence of a mental health disorder from 2010 to 2020 was 14.6%. After 1:1 matching, patients with a mental health disorder who underwent arthroscopic RCR were nearly twice as likely to undergo a revision procedure (odds ratio 1.94, 95% confidence interval 1.76-2.14, P < .001) and more than twice as likely to experience conversion to shoulder arthroplasty (odds ratio 2.29, 95% confidence interval 1.88-2.80, P < .001) within 2 years of initial arthroscopy when compared with patients without a mental disorder. Patients with a mental disorder also experienced increased risk for 90-day readmission (1.9% vs 0%, P < .001) as well as multiple postoperative medical complications. CONCLUSIONS: Patients with pre-existing mental health diagnoses experience increased rates of 90-day postoperative complications and readmissions following arthroscopic RCR. In addition, patients with mental health diagnoses are more likely to undergo revision repair and conversion to shoulder arthroplasty within 2 years of the index procedure. LEVEL OF EVIDENCE: Level III.

Delayed ACL reconstruction increases rates of concomitant procedures and risk of subsequent surgery.

PURPOSE: To utilise a large cross-sectional database to analyse the effects of time duration between diagnosis of anterior cruciate ligament (ACL) tear and ACL reconstruction (ACLR) on concomitant procedures performed and subsequent surgery within 2 years. METHODS: An analysis from 2015 to 2018 was performed using the Mariner PearlDiver Patient Records Database. Current Procedural Terminology (CPT), and International Classification of Diseases (ICD-10) codes identified patients with a diagnosis of ACL tear who underwent subsequent ACLR. Patients were stratified in biweekly and bimonthly increments based on the time duration between initial diagnosis of ACL tear and surgical treatment. Chi-squared analysis was used to compare categorical variables, and trend analysis was performed with Cochran-Armitage independence testing. RESULTS: Of 11,867 patients who underwent ACLR, 76.1% underwent surgery within 2 months of injury diagnosis. Patients aged 10-19 were most likely to undergo surgery within 2 months of injury diagnosis (83.5%, P < 0.0001). As duration from injury diagnosis to ACLR increased from < 2 months to > 6 months, rates of concomitant meniscectomy increased from 9.1% to 20.5% (P < 0.0001). The overall 2-year subsequent surgery rate was 5.3%. The incidence of revision ACLR was highest for patients who underwent surgery > 6 months after diagnosis (P < 0.0001), whilst the incidence of ipsilateral lysis of adhesions and manipulation under anaesthesia (MUA) was highest for patients who underwent surgery < 2 months after diagnosis (P < 0.0001). ACLR at 6-8 weeks after diagnosis demonstrated the lowest risk for concomitant procedures as well as 2-year subsequent surgery. CONCLUSION: The majority of patients undergo ACL reconstruction within 2 months of initial ACL tear diagnosis. Delayed surgery greater than 6 months after the diagnosis of an ACL rupture leads to increased need for concomitant meniscectomy as well as higher risk for revision ACLR within 2 years, but immediate surgery may increase risk for knee arthrofibrosis. LEVEL OF EVIDENCE: IV.