Faculty Bibliography

BACKGROUND:Synovial fluid (SF) biomarkers demonstrate time-dependent variation after acute knee injury, and it is postulated that persistently elevated inflammatory markers may mediate worse long-term outcomes. PURPOSE/OBJECTIVE:This study investigated the relationship between biomarkers in SF at the time of meniscectomy and long-term patient-reported outcomes in patients with acute versus chronic meniscal injuries. STUDY DESIGN/METHODS:Cohort study; Level of evidence, 3. METHODS:This retrospective analysis included patients who underwent knee SF aspiration on the day of arthroscopic meniscectomy between October 2011 and October 2020 with minimum 4-year follow-up. SF aspirated from the operative knee was analyzed for 10 pro- and anti-inflammatory biomarkers. Patients completed the visual analog scale for pain, Lysholm Knee Questionnaire, Tegner Activity Scale, and Knee injury and Osteoarthritis Outcome Score-Physical Function Short-form (KOOS-PS) before surgery and at follow-up. Patients were categorized as having acute (<6 weeks) or chronic (>1 year) symptoms. K-means clustering analysis was performed using biomarker levels to group patients into distinct cohorts. RESULTS:= .020) than the low-inflammation cohort. CONCLUSION/CONCLUSIONS:In patients with chronic meniscal injury, those with a more proinflammatory SF biomarker profile at the time of meniscectomy had worse outcomes than those who had a low inflammatory profile. In acute meniscal injuries, most patients demonstrate a high inflammatory profile, which was not associated with a difference in long-term outcomes.

BACKGROUND:While both short- and long-term outcomes after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) have been reported, the predictive relationship between the two has yet to be established. PURPOSE/OBJECTIVE:To determine whether the degree of improvement in patient-reported outcomes observed at 1 year postoperatively predicts long-term outcomes at 10 years after primary hip arthroscopy for FAIS. STUDY DESIGN/METHODS:Cohort study; Level of evidence, 3Methods:Patients who underwent primary hip arthroscopy for FAIS by a single surgeon at a single institution with 10-year follow-up were identified. Outcomes were assessed using the modified Harris Hip Score (mHHS) and Nonarthritic Hip Score (NAHS) at baseline and 1, 2, 5, and 10 years postoperatively. Patients were classified as either high improvement (HI) or low improvement (LI) based on if they achieved the median 1-year change in mHHS from baseline. Chart review was performed to collect surgical details such as operative procedures, complications, and revision surgery. Outcomes were compared between groups over time using repeated-measures analysis of variance. Failure rates were determined using Kaplan-Meier and Mantel-Cox log-rank analyses. RESULTS:= .002). CONCLUSION/CONCLUSIONS:Patients who experienced greater improvement in the first year after hip arthroscopy had superior 10-year outcome scores, fewer complications, and lower rates of reoperation compared with those who experienced minimal improvement in the same period.

BACKGROUND:Meniscal injuries trigger a local inflammatory response mediated by intra-articular mediators. Proinflammatory cytokines and chemokines can lead to cartilage degradation and subchondral bone changes, contributing to posttraumatic osteoarthritis. The role that age plays in this inflammatory response is unclear. PURPOSE/OBJECTIVE:To investigate age-dependent variation in cytokine types and concentrations in knee synovial fluid after meniscal injury. STUDY DESIGN/METHODS:Cohort study; Level of evidence, 3. METHODS:Patients undergoing arthroscopic knee surgery for isolated meniscal injury were prospectively enrolled between July 2011 and April 2024. Synovial fluid was aspirated from the operative knee, and concentrations of 10 biomarkers were measured. Patients at least 9 years after surgery were invited to complete patient-reported outcome (PRO) surveys. Multivariable linear regression assessed pairwise relationships between age at surgery, log-normalized biomarker concentrations, and PROs, while adjusting for relevant covariates. Conditional process analysis was used to explore age-biomarker relationships, with symptom duration as a moderator and baseline Outerbridge grade as a mediator. RESULTS:The study included 160 patients for biomarker analysis with a mean ± SD age of 50.2 ± 12.5 years. Forty-seven patients who reached a minimum 9 years of follow-up completed PRO surveys. Mean follow-up was 10.2 ± 1.3 years. Regression analysis revealed positive associations between age and log-normalized concentration of preoperative IL-6. Moderator analysis found age to be positively associated with IL-6, VEG-F, and IL-1Ra in chronic meniscal injuries. Mediator analysis found an indirect positive relationship between age and MIP-B, VEGF, and MMP-3 and an indirect negative relationship between age and TIMP-1 and TIMP-2. Preoperative TIMP-1 was positively associated with 10-year Knee injury and Osteoarthritis Outcome Score-Physical Function Short Form score and elevated in treatment responders. CONCLUSION/CONCLUSIONS:Age at surgery was associated with higher concentrations of proinflammatory biomarkers and lower concentrations of anti-inflammatory biomarkers in the synovial fluid before meniscal surgery. Anti-inflammatory markers were associated with improved long-term PROs. These findings suggest an age-related intensification of the proinflammatory response and inhibition of the anti-inflammatory response that may contribute to long-term functional decline in older patients after meniscal surgery. There is potential for age-specific immunomodulatory therapeutic strategies to manage inflammation and mitigate the progression toward posttraumatic osteoarthritis in older patients.

PURPOSE/OBJECTIVE:The purpose of this study was to evaluate patient-reported outcomes (PROs) and survivorship in obese patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) at 10-year follow-up. METHODS:A retrospective review was conducted of patients who underwent arthroscopy for FAIS from 2010-2013. Patients were assessed at baseline, 1 month, 6 months, 1-, 2-, 5-, and 10 years using the modified Harris Hip Score (mHHS) and Nonarthritic Hip Score (NAHS). Patients were categorized based on BMI into normal, overweight, and obese cohorts. Minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS) were calculated for both PROs. Improvements from baseline were analyzed and differences between groups were evaluated while controlling for age. Survival to revision surgery was assessed with Kaplan-Meier survival curves. RESULTS:144 patients (65.2% female) with a mean age of 38.8 ± 13.0 years and an average follow-up of 11.6 (range 10.0-13.8) years were included, and categorized into normal weight (59.7%), overweight (26.4%), and obese (13.9%). All groups showed significant improvement in PROs at 10 years compared to baseline (p=0.007). Obese patients had lower postoperative scores (mHHS: 72.8 vs. 90.1, p=0.009; NAHS: 68.4 vs.. 88.6, p=0.003) and improvement in scores from baseline (mHHS: 23.4 vs. 37.7, p=0.013; NAHS: 18.4 vs. 40.0, p=0.004) at 10-year follow-up, as well as lower achievement of mHHS PASS (60.0% vs 87.2%, p=0.015), NAHS PASS (50.0% vs. 89.5%, p<.001) and NAHS MCID (70.0% vs. 93.0%, p=0.008). Obese patients also had a higher rate of conversion to THA (17.4% vs 3.3%, p=0.012). The overall complication rate was 4.2% compared to 10% in the obese group, with obese patients experiencing a superficial infection more frequently (p=0.002). CONCLUSION/CONCLUSIONS:Although obese patients still have significantly improved outcomes compared to baseline, at 10-year follow-up they have inferior outcomes compared to nonobese patients and higher rates of conversion to THA. LEVEL OF EVIDENCE/METHODS:Level III, retrospective comparative study.

PURPOSE/OBJECTIVE:To identify the risk of anterior cruciate ligament (ACL) injury in adolescent athletes based on sex, sport, and sport affiliation. METHODS:A literature search was performed using 3 online databases (PubMed, Cochrane Library, and EMBASE) from database inception to November 2023 per the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included studies consisted of Level I or II studies reporting on ACL injury exposures in time (hours) or injuries per 1,000 athlete-exposures (AEs) (1 game or practice) in adolescent athletes. Exclusion criteria consisted of non-English studies, case reports, animal/cadaveric studies, and review articles. Methodological quality and bias assessment of the included studies was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. ACL injuries were analyzed and pooled to calculate incidence rates (IRs), per-season risk, and relative risk (RR) based on sex, sport, and sport affiliation (club sport participation vs school sport participation). RESULTS:A total of 1,389 ACL injuries over 19,134,167 AEs were identified (IR, 0.075; 95% confidence interval [CI], 0.071-0.079). Of these, 670 ACL injuries were reported in female athletes over 7,549,892 AEs (IR, 0.089; 95% CI, 0.087-0.091) with 719 in males over 11,584,275 AEs (IR, 0.062; 95% CI, 0.058-0.067). The greatest RR for ACL injury in females was in soccer (RR, 3.12; 95% CI, 2.58-3.77) for AEs. The greatest per-season risk of ACL injuries reported in female athletes occurred in soccer (1.08%), basketball (1.03%), and gymnastics (1.01%). The greatest per-season risk of ACL injuries reported in male athletes occurred in football (0.82%), lacrosse (0.64%), and soccer (0.35%). Club sport participation, in both AEs (RR, 3.94; 95% CI, 3.19-4.87) and hours of exposure (RR, 1.57; 95% CI, 1.07-2.28), demonstrated an increased risk of ACL injury. CONCLUSIONS:The risk of ACL injuries was 1.56-fold greater in adolescent female athletes compared with male athletes. The highest-risk sport for females was soccer. Participation in club sports possessed higher rates of injury compared with school sports. LEVEL OF EVIDENCE/METHODS:Level II; meta-analysis of Level I and II studies.

Hip arthroscopy is an effective procedure with rapidly improving techniques and implants. Routine labral and capsular repair are broadly agreed upon as standard of care in most cases, which is now supported by long-term outcome studies. A crucial component of patient postoperative success is physical therapy. While accelerated programs are appealing, biomechanical studies have consistently demonstrated decreased stability at time-zero following hip arthroscopy, particularly labral repairs. Therefore, though we want to help our patients get back to their lives as soon as possible, it remains our responsibility to protect their hip in the early postoperative period. If, in ideal laboratory conditions, we cannot restore stability to an intact state, then we must presuppose that the suction seal improves as the capsule, and more importantly, the labrum, heals after surgical manipulation. This means we are not able to rely solely on the strength of our repair, and there is a distinct period where the repaired hip is particularly vulnerable. Most hip arthroscopy protocols utilize a protective period, ranging from 4-8 weeks, where there is an emphasis on passive range of motion only, with a strict moratorium on "pushing beyond pain."

PURPOSE/OBJECTIVE:This study aims to evaluate patient-reported outcomes (PROs) and reoperation rates in patients undergoing primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) over a minimum 10-year follow-up stratified by sex, age, and body mass index (BMI). METHODS:Primary hip arthroscopies performed for FAIS between 2010 and 2013, with a minimum 10-year follow-up, were reviewed. Procedures consisting of microfracture, or labral debridement without repair, were excluded. Ten-year PROs were assessed using the modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS). Patients were categorized into three groups by age (<30, 30-44, >45 years) and BMI (<25.0, 25.0-29.9, ≥30). Minimum clinically important difference (MCID) was set to half the preoperative standard deviation of the cohort. Reoperation rates and PROs were compared, and regression analysis identified independent predictors of PROs. RESULTS:At minimum 10-year follow-up (mean: 11.6 [10.0-13.9] years), 59.2% follow-up was achieved, representing 154 hips (141 patients). The cohort had a mean age of 38.5 years, BMI of 24.4, and was 68.2% female. At follow-up, 91.6% of the cohort achieved MCID with a 9.7% re-operation rate. In the middle-aged group, males had higher mHHS (mean, 92.8 vs. 85.2, P = 0.015) and NAHS (mean, 91.6 vs. 83.4, P = 0.008) scores compared to females. In the BMI ≥30 group, males had higher mHHS (mean, 83.3 vs. 66.4, P = 0.030) and NAHS scores (mean, 83.0 vs. 58.5, P = 0.035). Only 72.7% of females with BMI ≥30 achieved MCID for mHHS and NAHS, compared to BMI < 25 (96.6% and 94.9%, respectively) and 25-29.9 (87.5% and 83.3%) (mHHS: P = 0.016; NAHS: P = 0.038). Similarly, 78.8% of females aged ≥ 45 achieved MCID for NAHS, compared to 92.9% of those aged < 30 and 97.1% of those 30-44 (P = 0.040). Multivariable regression identified older age (mHHS: P=0.019; NAHS: P=0.042) and higher BMI (mHHS: P=0.007; NAHS: P<0.001) as independently predictive of worse 10-year PROs. CONCLUSION/CONCLUSIONS:Older age and greater BMI independently predicted poorer long-term functional outcomes after hip arthroscopy for FAIS. Female sex, while not independently predictive, may make patients more susceptible to the negative effects of older age and BMI. No significant association was observed for reoperation rates. LEVEL OF EVIDENCE/METHODS:Level IV, retrospective therapeutic case series.

PURPOSE/OBJECTIVE:To compare pre- and post-operative findings between patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) with lateral impingement versus those without lateral impingement METHODS: Patients who underwent primary hip arthroscopy for FAIS between 2012-2017 with minimum 5-year follow-up were included. Alpha angle (AA) was measured on preoperative AP and 90° Dunn radiographs. Patients with AA > 60° on Dunn view but not AP view (no lateral impingement) were propensity matched by sex, age, and BMI in a 1:3 ratio to patients with AA > 60° on both views (lateral impingement). Demographic characteristics, radiographic and intraoperative findings, reoperation rates, and patient-reported outcomes (PROs) were compared between groups. Categorical variables were compared us Fisher's exact testing and continuous variable using two-tailed student's t tests. RESULTS:Sixty patients with lateral impingement (65.0% female, age: 35.3 ± 13.0 years) were matched to 180 patients without lateral impingement (65.0% female, age: 34.7 ± 12.5 years, p ≥ 0.279). Lateral impingement patients had larger preoperative AAs on both Dunn (71.0° ± 8.8° vs. 67.6° ± 6.1°, p = 0.001) and AP radiographs (79.0° ± 12.1° vs. 48.2° ± 6.5°, p < 0.001). However, there were no differences in postoperative AAs on either view (Dunn: 39.0° ± 6.1° vs. 40.5° ± 5.3°, AP: 45.8° ± 9.0° vs. 44.9° ± 7.0°, p ≥ 0.074). Labral tears began more superiorly in patients with lateral impingement (12:00 ± 0:49 vs. 12:17 ± 0:41, p = 0.030), and theydemonstrated higher rates of acetabular and femoral cartilage damage (p = 0.030 for both); however, there were no differences in PROs or reoperation rates between the groups at 5-year follow-up. CONCLUSIONS:Although cam deformities located laterally and anterolaterally are larger than those located anterolaterally alone, both can be resected adequately, resulting in similar postoperative radiographic measurements, PROs, and survivorship.

Acetabular cartilage delamination (ACD) can result in focal chondral defects, increasing contact stresses and contributing to osteoarthritis. This is commonly associated with femoroacetabular impingement, particularly with cam deformities due to shearing of the cam on the acetabulum. Additionally, ACD associated with labral tears or chondrolabral separation, when untreated, can compromise labral repair outcomes. ACD is often missed on preoperative magnetic resonance imaging and magnetic resonance arthrography, which show a sensitivity of <80%. Thus, given the ubiquity of ACD in patients undergoing femoroacetabular impingement surgery, a single-stage treatment option is essential. Acetabular shape, depth, and constraint, coupled with the thinness of acetabular cartilage, make treatment technically difficult, particularly arthroscopically. Treatment generally falls within 3 categories: repair, repair with augmentation, or cell-based cartilage transplantation. Currently, we most commonly employ primary repair and incorporate the cartilage flap into the labral repair. The chondral nail described by Zhu et al. is an intriguing off-the-shelf, single-stage technique that merits further investigation.

PURPOSE/OBJECTIVE:To evaluate knee intra-articular cytokine concentrations in patients undergoing isolated meniscectomy and determine if these concentrations are associated with clinical outcomes. METHODS:Concentrations of ten biomarkers were quantified in synovial fluid aspirated from the operative knees of patients who underwent isolated meniscectomy from 10/2011-12/2019. Patients completed a survey at final follow-upincluding VAS, Lysholm, Tegner, and KOOS Physical Function Short Form (KOOS-PS). Failure was defined as subsequent TKA or non-achievement of the Patient Acceptable Symptom State (PASS) for knee pain defined as VAS > 27/100. Regression analysis investigating the relationship between cytokine concentrations and failure was performed. RESULTS:[25.5, 32.4], and a mean follow-up of 8.0 ± 2.2 years. There were no demographic or clinical differences between failures (n = 41) and non-failures (n = 59) at baseline. Monocyte Chemotactic Protein 1 (MCP-1) concentration was significantly higher in failures than in non-failures (344.3 pg/ml vs. 268.6 pg/ml, p = 0.016). In a regression analysis controlling for age, sex, BMI, symptom duration, length of follow-up, and ICRS grade, increased MCP-1 was associated with increased odds of failure (p = 0.002). CONCLUSIONS:The concentration of MCP-1 on the day of arthroscopic meniscectomy was predictive of failure as defined by an unacceptable pain level at intermediate- to long-term follow-up. This finding may help identify patients at high risk for poor postoperative outcomes following isolated meniscectomy and serve as a target for future postoperative immunomodulation research.