Seasonal Variation of Pediatric Septic Arthritis in the United States: A PHIS Database Study.

BACKGROUND: The presence of seasonal patterns in pediatric septic arthritis cases is a common orthopaedic teaching. Seasonal variation has been seen in centers outside of the United States and with other inflammatory and infectious joint-related conditions within the country, but it is unknown if a seasonal pattern exists among different regions of the United States. The purpose of this study was to examine the seasonal variation of septic arthritis within specific regions across the United States. METHODS: The Pediatric Health Information System database was queried for all patients 19 years or younger who were treated for septic arthritis. Data from 34 pediatric hospitals in the Pediatric Health Information System initiative were included. Centers were organized by geographical region, and season of presentation was determined using equinoxes/solstices. χ 2 tests were performed to detect seasonal differences in septic arthritis for the entire cohort and separated by geographical region. Proportion differences along with 95% CIs were provided. RESULTS: Between 2016 and 2019, there were 5764 cases of septic arthritis. Median age at diagnosis was 6.2 years (range: 0 to 19.0 y). Each season contributed 24% to 25% of the total septic arthritis cases, and there were no significant differences detected between the 4 seasons ( P =0.66). There was no seasonal variation seen in the Midwest, South, or West ( P =0.71, 0.98, 0.36, respectively). However, there was seasonal variation in the Northeast ( P =0.05), with fall and summer having a higher percentage of cases (28%) than the winter (21%). CONCLUSIONS: This study showed no clear seasonal variation in septic arthritis in children across the United States using a national database of pediatric hospital centers. However, there is regional seasonal variation in the Northeast, which may relate to climate differences. With no clear seasonal variation across the United States, continued diligence is needed in diagnosing septic arthritis throughout the year. LEVEL OF EVIDENCE: Prognostic II.

Intrarater and Interrater Reliability of Radiographic Characteristics in Skeletally Immature Patients With Anterior Cruciate Ligament Tears: A PLUTO Study Group Reliability Study.

BACKGROUND: Radiographic measurements of limb alignment in skeletally immature patients with anterior cruciate ligament (ACL) tears are frequently used for surgical decision-making, preoperative planning, and postoperative monitoring of skeletal growth. However, the interrater and intrarater reliability of these radiographic characteristics in this patient population is not well documented. HYPOTHESIS: Excellent reliability across 4 raters will be demonstrated for all digital measures of length, coronal plane joint orientation angles, mechanical axis, and tibial slope in skeletally immature patients with ACL tears. STUDY DESIGN: Cohort study (diagnosis). METHODS: Three fellowship-trained orthopaedic surgeons and 1 medical student performed 2 rounds of radiographic measurements on digital imaging (lateral knee radiographs and long-leg radiographs) of skeletally immature patients with ACL tears. Intrarater and interrater reliability for continuous radiographic measurements was assessed with intraclass correlation coefficients (ICCs) across 4 raters with 95% CIs for affected and unaffected side measurements. Interrater reliability analysis used an ICC (2, 4) structure and intrarater reliability analysis used an ICC (2, 1) structure. A weighted kappa coefficient was calculated for ordinal variables along with 95% CIs for both interrater and intrarater reliability. Agreement statistic interpretations are based on scales described by Fleiss, and Cicchetti and Sparrow: <0.40, poor; 0.40 to 0.59, fair; 0.60 to 0.74, good; and >0.74, excellent. RESULTS: Radiographs from a convenience sample of 43 patients were included. Intrarater reliability was excellent for nearly all measurements and raters. Interrater reliability was also excellent for nearly all reads for all measurements. CONCLUSION: Radiographic reliability of long-leg radiographs and lateral knee x-rays in skeletally immature children with ACL tears is excellent across nearly all measures and raters and can be obtained and interpreted as reliable and reproducible means to measure limb length and alignment. LEVEL OF EVIDENCE: Level III.

Better Patient Care Through Physician Extenders and Advanced Practice Providers.

Physician extenders and advanced practice providers (APPs) are now common in most adult and pediatric orthopaedic clinics and practices. Their utilization, with physician leadership, can improve patient care, patient satisfaction, and physician satisfaction and work/life balance in addition to having financial benefits. Physician extenders can include scribes, certified athletic trainers, and registered nurses, while APPs include nurse practitioners and physician assistants/associates. Different pediatric orthopaedic practices or divisions within a department might benefit from different physician extenders or APPs based on particular skill sets and licensed abilities. This article will review each of the physician extender and APP health care professionals regarding their training, salaries, background, specific skill sets, and scope of practice. While other physician extenders such as medical assistants, cast technicians, and orthotists/prosthetists have important roles in day-to-day clinical care, they will not be reviewed in this article. In addition, medical trainees, including medical students, residents, fellows, and APP students, have a unique position within some academic clinics but will also not be reviewed in this article. With the many different local, state, and national regulations, a careful understanding of the physician extender and APP roles will help clinicians optimize their ability to improve patient care.

Male and Female Adolescent Athletes' Readiness to Return to Sport After Anterior Cruciate Ligament Injury and Reconstruction.

OBJECTIVE: The purpose of this study was to examine whether readiness to return to sport (RTS) differed between adolescent male and female athletes after anterior cruciate ligament reconstruction (ACLR). DESIGN: Longitudinal, prospective cohort. SETTING: Outpatient office associated with tertiary-care hospital. PATIENTS: A total of 93 adolescent athletes, 17 years of age and younger, who underwent ACLR surgery with a hamstring autograft were included. INDEPENDENT VARIABLES: Male and female athletes. MAIN OUTCOME MEASURES: Anterior cruciate ligament-return to sport after injury (ACL-RSI) completed at 3 time points: (1) preoperatively (Pre-op), (2) approximately 3 months into rehabilitation (Post-op 1), and (3) during RTS phases of recovery (Post-op 2). RESULTS: There was a significant main effect for both sex (P < 0.010) and time (P < 0.0001) with male athletes having higher ACL-RSI scores than female athletes at all 3 time points; however, there was no significant time by sex interaction. All ACL-RSI scores increased significantly across time, regardless of sex. There were no statistically significant differences between ACL-RSI scores at all 3 time points between individuals who did and did not receive physician clearance. CONCLUSIONS: This study provides a longitudinal depiction of adolescent athletes' readiness to RTS after ACL injury throughout recovery. Both male and female athletes demonstrated diminished ACL-RSI scores before undergoing surgery, with increasing scores at both postoperative time points for both sexes. Overall, female athletes reported lower readiness to RTS at all 3 time points compared with male athletes.

Nationwide Ethnic/Racial Differences in Surgical Treatment of Discoid Meniscus in Children: A PHIS Database Study.

BACKGROUND: Discoid meniscus, a congenital meniscus variant, may have greater incidence in Asian populations. No US population-based studies have examined the discoid meniscus ethnic/racial distribution. In pediatric patients undergoing meniscus surgery, it is hypothesized that ethnic/racial variability exists in patients with discoid meniscus and this variability is different than in patients with medial meniscus tears. METHODS: The Pediatric Health Information System was queried from 48 hospitals to examine patients 18 years of age and younger between 2015 and 2019, using International Classification of Diseases, 10th Revision, Clinical Modification codes. A cohort of patients treated surgically for discoid meniscus was compared with a cohort of patients treated surgically for medial meniscal tear. These 2 populations were compared based on age, sex, ethnicity/race, Current Procedural Terminology code, insurance, urban versus rural, and region of country. Univariate testing and multivariable logistic modeling were used to test for associations. RESULTS: A discoid meniscus cohort of 399 children (median age, 13.0 y) was compared with a medial meniscus tear cohort of 3157 children (median age, 16.0 y) (P<0.001). Hispanic/Latino children accounted for 36.8% of the discoid lateral meniscus and 22.7% of the medial meniscus populations (P<0.001). Among pediatric patients that had surgery for discoid lateral meniscus or medial meniscus, Hispanic/Latino children had 2.36 times the odds of surgery for discoid meniscus compared with White patients after adjusting for age and insurance (P<0.001). Asian children also had 2.41 times the odds of surgery for discoid meniscus compared with White patients (P=0.017). CONCLUSIONS: This study shows a significant association of ethnicity/race with discoid versus medial meniscus surgical treatment in children. Among pediatric patients undergoing surgery for discoid meniscus, Hispanic/Latino and Asian patients were a significantly larger percentage of the population than White patients. Hispanic/Latino children made up a greater percentage of the population having surgery for a torn discoid meniscus versus a torn medial mensicus. When evaluating pediatric patients, younger age and Asian or Hispanic/Latino ethnicity should increase attention to the possibility of a discoid meniscus. LEVEL OF EVIDENCE: Level IV.

Lack of Sleep and Sports Injuries in Adolescents: A Systematic Review and Meta-analysis.

BACKGROUND: Although sleep has been identified as an important modifiable risk factor for injury, the effect of decreased sleep on sports injuries in adolescents is poorly studied. The objective of this study was to quantitatively and qualitatively review published literature to examine if a lack of sleep is associated with sports injuries in adolescents and to delineate the effects of chronic versus acute lack of sleep. METHODS: PubMed (includes MEDLINE) and EMBASE databases were systematically searched using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were included if they reported statistics regarding the relationship between sleep and sports injury in adolescents aged 19 years or younger published between January 1, 1997 and December 21, 2017. From these included studies, the following information was extracted: bibliographic and demographic information, reported outcomes related to injury and sleep, and definitions of injury and decreased sleep. A random effects model was then created to quantify the odds of injury with decreased sleep in adolescents. RESULTS: Of 907 identified articles, 7 met inclusion criteria. Five studies reported that adolescents who chronically slept poorly were at a significantly increased likelihood of experiencing a sports or musculoskeletal injury. Two studies reported on acute sleep behaviors. One reported a significant positive association between acutely poor sleep and injury, whereas the other study reported no significant association. In our random effects model, adolescents who chronically slept poorly were more likely to be injured than those who slept well (OR, 1.58; 95% CI, 1.05-2.37; P=0.03). CONCLUSIONS: Chronic lack of sleep in adolescents is associated with greater risk of sports and musculoskeletal injuries. Current evidence cannot yet definitively determine the effect of acute lack of sleep on injury rates. LEVEL OF EVIDENCE: Level IV-systematic review of level II studies and one level IV study.

All-Epiphyseal Anterior Cruciate Ligament Femoral Tunnel Drilling: Avoiding Injury to the Physis, Lateral Collateral Ligament, Anterolateral Ligament, and Popliteus-A 3-Dimensional Computed Tomography Study.

PURPOSE: To investigate the relation of the at-risk structures (distal femoral physis, lateral collateral ligament, anterolateral ligament, popliteus, and articular cartilage) during all-epiphyseal femoral tunnel drilling. A second purpose was 2-fold: (1) to develop recommendations for tunnel placement and orientation that anatomically reconstruct the anterior cruciate ligament (ACL) while minimizing the risk of injury to these at-risk structures, and (2) to allow for maximal tunnel length to increase the amount of graft in the socket to facilitate healing. METHODS: Three-dimensional models of 6 skeletally immature knees (aged 7-11 years) were reconstructed from computed tomography and used to simulate all-epiphyseal femoral tunnels. Tunnels began within the ACL footprint and were directed laterally or anterolaterally, with the goal of avoiding injury to at-risk structures. The spatial relation between the ideal tunnel and these structures was evaluated. Full-length tunnels and partial length condyle sockets were simulated in the models using the same trajectories. RESULTS: An anterolateral tunnel could be placed to avoid direct injury to lateral structures. The safe zone on the anterolateral aspect of the femur was larger than that of a tunnel with a direct lateral trajectory (median 127 mm2 vs 83 mm2, P = .028). Anterolateral tunnels were longer than direct lateral tunnels (median 30 mm vs 24 mm, P = .041). Safe angles for anterolateral tunnels were 34° to 40° from the posterior condylar axis; direct lateral tunnels were drilled 4° to 9° from the posterior condylar axis. Sockets could be placed without direct injury to structures at risk with either orientation. CONCLUSIONS: An all-epiphyseal ACL femoral tunnel can be placed without causing direct injury to at-risk structures. A tunnel angled anterolaterally from the ACL origin is longer and has a larger safe zone compared with the direct lateral tunnel. CLINICAL RELEVANCE: The largest safe zone for femoral all-epiphyseal ACL drilling was (1) anterior to the lateral collateral ligament origin, (2) distal to the femoral physis, and (3) proximal to the popliteus tendon origin. A direct lateral tunnel may also be used, but has a smaller safe zone. Sockets or partial length tunnels may have a lower risk of injury to at-risk structures.

Back Pain in a Pediatric Emergency Department: Etiology and Evaluation.

OBJECTIVES: Back pain is an uncommon chief complaint in the pediatric emergency department (ED). However, there are serious underlying conditions requiring prompt diagnosis and treatment. While the etiology is usually benign, variation exists in the evaluation. The study purpose was to describe pediatric patients who presented to the ED with back pain and evaluate for associations with laboratory and radiologic abnormalities indicative of underlying musculoskeletal pathology. METHODS: A retrospective review was conducted of patients aged birth to 18 years who presented to a pediatric ED with a chief complaint of back pain during a 1-year period. Primary outcome was discharge diagnosis, categorized as nonpathologic back pain, pathologic back pain, and other etiologies. Descriptive statistics were used. RESULTS: Two-hundred thirty-two patient encounters were reviewed, with 177 included in data analysis. A nonpathologic diagnosis of back pain was found in 76.8% of visits. Back pain and back or muscle strain were the most common diagnoses. Pathologic back pain diagnoses represented 2.3% of visits. Radiologic imaging was performed in 37.9%. Positive findings were noted in 16.9% of radiographs; no abnormalities were noted on computed tomography scan or magnetic resonance imaging. Laboratory studies were conducted in 35%. Abnormal plain radiographs were associated with a pathologic diagnosis of back pain (P < 0.001). CONCLUSIONS: Most pediatric patients presenting to the ED with back pain were found to have a nonpathologic etiology and were discharged. Among those with a pathologic back pain diagnosis, abnormal radiograph findings were the only statistically significant factor, whereas laboratory studies, computed tomography scans, and magnetic resonance imaging scans were less indicative.

Anterolateral Ligament of the Knee Shows Variable Anatomy in Pediatric Specimens.

BACKGROUND: Anterior cruciate ligament (ACL) reconstruction failure rates are highest in youth athletes. The role of the anterolateral ligament in rotational knee stability is of increasing interest, and several centers are exploring combined ACL and anterolateral ligament reconstruction for these young patients. Literature on the anterolateral ligament of the knee is sparse in regard to the pediatric population. A single study on specimens younger than age 5 years demonstrated the presence of the anterolateral ligament in only one of eight specimens; therefore, much about the prevalence and anatomy of the anterolateral ligament in pediatric specimens remains unknown. QUESTIONS/PURPOSES: We sought to (1) investigate the presence or absence of the anterolateral ligament in prepubescent anatomic specimens; (2) describe the anatomic relationship of the anterolateral ligament to the lateral collateral ligament; and (3) describe the anatomic relationship between the anterolateral ligament and the physis. METHODS: Fourteen skeletally immature knee specimens (median age, 8 years; range, 7-11 years) were dissected (12 male, two female specimens). The posterolateral structures were identified in all specimens, including the lateral collateral ligament and popliteus tendon. The presence or absence of the anterolateral ligament was documented in each specimen, along with origin, insertion, and dimensions, when applicable. The relationship of the anterolateral ligament origin to the lateral collateral ligament origin was recorded. RESULTS: The anterolateral ligament was identified in nine of 14 specimens. The tibial attachment point was consistently located in the same region on the proximal tibia, between the fibular head and Gerdy's tubercle; however, the femoral origin of the anterolateral ligament showed considerable variation with respect to the lateral collateral ligament origin. The median femoral origin of the anterolateral ligament was 10 mm (first interquartile 6 mm, third interquartile 13) distal to the distal femoral physis, whereas its median insertion was 9 mm (first interquartile 5 mm, third interquartile 11 mm) proximal to the proximal tibial physis. CONCLUSIONS: The frequency of the anterolateral ligament in pediatric specimens we observed was much lower than other studies on adult specimens; future studies might further investigate the prevalence, development, and functional role of the anterolateral ligament of the knee. CLINICAL RELEVANCE: This study expands our understanding of the anterolateral ligament and provides important anatomic information to surgeons considering anterolateral ligament reconstruction concomitantly with primary or revision ACL reconstruction in pediatric athletes.

The association of tibial slope and anterior cruciate ligament rupture in skeletally immature patients.

PURPOSE: The purpose of our study was to investigate the relation between posterior tibial slope and anterior cruciate ligament (ACL) rupture in patients with open physes. METHODS: A retrospective case-control study was performed comparing skeletally immature patients with an ACL rupture with an age-matched control group. Posterior tibial slope was measured on plain lateral radiographs in both groups by blinded readers, at 2 separate time intervals, using a previously examined and accepted technique. RESULTS: Thirty-two patients were included in the study group (mean age, 13 years; age range, 9 to 17 years) and compared with 32 patients in the control group (mean age, 13 years; age range, 9 to 16 years). The mean posterior tibial slope in the ACL-injured population was 10.0° ± 3° versus 8.5° ± 3° in the control group (P = .0128). Statistical significance was seen in comparisons of slope measurements between the ACL-injured and control groups for 2 of the 3 readers (readers 1 and 3) at both time points (P = .0348 and P = .0051 for reader 1 and P = .0009 and P = .0059 for reader 3). Intrarater reliability proved superior with values correlating with moderate to good reliability, whereas inter-rater reliability values corresponded with fair to moderate reliability. The average posterior tibial slope was 9.5° (range, 3° to 14°) for female patients and 9.8° (range, 2° to 16°) for male patients. CONCLUSIONS: On the basis of the results of this study, the data support the notion that a moderate association may exist between an increased posterior tibial slope and ACL injury in pediatric patients with open physes. LEVEL OF EVIDENCE: Level III, case-control study.

Knee Pain and Patellofemoral Symptoms in Patients With Cerebral Palsy.

BACKGROUND: Knee pain in cerebral palsy (CP) is associated with increased patellofemoral forces present when walking with flexed knees. In typically developing children, knee pain and patellofemoral dysfunction are associated with obesity, genu valgum, femoral anteversion, and external tibial torsion. These problems are also common in CP, and may contribute to knee problems in this population. The purposes of this study were to define the prevalence of knee pain and patellofemoral dysfunction in children with CP, and to identify physical and gait characteristics (using 3-dimensional gait analysis data) that predispose them to such problems. METHODS: Retrospective review of 121 children with CP, Gross Motor Function Classification System level I to IV, who underwent computerized gait analysis testing. Demographics, range of motion, body mass index and hip, knee, and ankle kinematics were compared between subjects with and without knee pain. RESULTS: Twenty-five of 121 subjects (21%) reported knee pain at the time of testing. Three of 121 subjects (2%) had a history of patellar subluxation/dislocation. Age and sex were significantly related to presence of knee pain. The likelihood of knee pain was almost 5 times higher in females (odds ratio=4.9, [95% confidence interval, 1.8-13.3], P=0.002), with a prevalence of 40% (17/42) in females versus 10% (8/79) in males. The likelihood of knee pain increased with age by approximately 13% per year (odds ratio=1.13, [95% confidence interval, 1.00-1.28], P=0.058). Malignant malalignment syndrome showed a potential relationship to more severe knee pain (P=0.05), which warrants further investigation. Body mass index, pes valgus, and degree of stance knee flexion showed no statistically significant relationships to knee pain (P>0.16). CONCLUSIONS: The prevalence of knee pain in ambulatory patients with CP is approximately 21%. Patellar subluxation (2%) and dislocation are rare in these patients. Knee pain is not always related to crouch, femoral anteversion, external tibial torsion, genu valgum, or pes valgus. Knee pain in these patients is more prevalent in females, and increases with increasing age. LEVEL OF EVIDENCE: Level III-case-control study.

Anterior ankle impingement: diagnosis and treatment.

Anterior ankle impingement is a common clinical condition characterized by chronic anterior ankle pain that is exacerbated on dorsiflexion. Additional symptoms include instability; limited ankle motion; and pain with squatting, sprinting, stair climbing, and hill climbing. Diagnosis is typically confirmed with plain radiographs. Nonsurgical management includes physical therapy, strengthening exercises, activity modification, bracing, and anti-inflammatory medication. Although arthroscopic treatment is sufficient in some patients, most require an open approach to address related pathology. We advocate aggressive range of motion as well as weight bearing postoperatively. Further study is needed to confirm current understanding of anterior ankle impingement and to better define treatment options and prevention strategies.

Tibial tunnel placement accuracy during anterior cruciate ligament reconstruction: independent femoral versus transtibial femoral tunnel drilling techniques.

PURPOSE: This study aimed to compare the accuracy of tibial tunnel placement using independent femoral (IF) versus transtibial (TT) techniques. METHODS: Ten matched pairs of cadaveric knees were randomized so that one knee in the pair underwent arthroscopic TT drilling of the femoral tunnel and the other underwent IF drilling through an accessory medial portal. For both techniques, an attempt was made to place the femoral and tibial tunnels as close to the center of the respective anterior cruciate ligament (ACL) footprints as possible. Preoperative and postoperative computed tomography using a technique optimized for ligament evaluation allowed comparison of the anatomic ACL tibial footprint to the tibial tunnel aperture. The percentage of tunnel aperture contained within the native footprint, as well as the distance from the center of the tunnel aperture to the center of the footprint, was measured. Additionally, graft obliquity relative to the tibial plateau was evaluated in the sagittal plane. RESULTS: The percentage of tibial tunnel aperture contained within the native footprint averaged 71.6% ± 17.2% versus 52.1% ± 23.4% (P = .04) in the IF and TT groups, respectively. The distance from the center of the footprint to the center of the tibial tunnel aperture was 3.50 ± 1.6 mm and 4.40 ± 1.7 mm (P = .27) in the IF and TT groups, respectively. TT drilling placed 6 of 10 tunnels posterior to the center of the footprint versus 3 of 10 tunnels in IF drilling. The graft obliquity angles were 54.8° in TT specimens and 47.5° in IF specimens (P = .09). CONCLUSIONS: This study adds to the literature suggesting that TT drilling with an 8-mm reamer has deleterious effects on tibial tunnel aperture and position. IF drilling, which does not involve repeated reaming of the tibial tunnel, is associated with the placement of a higher percentage of the tunnel aperture within the native tibial footprint. There was not a significant difference between the IF and TT techniques in their ability to place the center of the tibial aperture near the center of the footprint or in graft obliquity. CLINICAL RELEVANCE: ACL reconstruction has continued to evolve in an attempt to restore the functional anatomy and biomechanical behavior of the knee. Tibial tunnel characteristics-such as location, aperture topography, and tunnel obliquity-are important factors to consider in ACL reconstruction. This study compares tibial tunnels after IF and TT techniques.

Chronic lack of sleep is associated with increased sports injuries in adolescent athletes.

BACKGROUND: Much attention has been given to the relationship between various training factors and athletic injuries, but no study has examined the impact of sleep deprivation on injury rates in young athletes. Information about sleep practices was gathered as part of a study designed to correlate various training practices with the risk of injury in adolescent athletes. METHODS: Informed consent for participation in an online survey of training practices and a review of injury records was obtained from 160 student athletes at a combined middle/high school (grades 7 to 12) and from their parents. Online surveys were completed by 112 adolescent athletes (70% completion rate), including 54 male and 58 female athletes with a mean age of 15 years (SD=1.5; range, 12 to 18 y). The students' responses were then correlated with data obtained from a retrospective review of injury records maintained by the school's athletic department. RESULTS: Multivariate analysis showed that hours of sleep per night and the grade in school were the best independent predictors of injury. Athletes who slept on average <8 hours per night were 1.7 times (95% confidence interval, 1.0-3.0; P=0.04) more likely to have had an injury compared with athletes who slept for ≥8 hours. For each additional grade in school, the athletes were 1.4 times more likely to have had an injury (95% confidence interval, 1.2-1.6; P<0.001). CONCLUSION: Sleep deprivation and increasing grade in school appear to be associated with injuries in an adolescent athletic population. Encouraging young athletes to get optimal amounts of sleep may help protect them against athletic injuries. LEVEL OF EVIDENCE: Level III.

Synovial fluid findings in children with knee monoarthritis in lyme disease endemic areas.

BACKGROUND: Although Lyme and septic arthritis of the knee may have similar clinical presentations, septic arthritis requires prompt identification and treatment to avoid joint destruction. We sought to determine whether synovial fluid cell counts alone can discriminate between Lyme, septic, and other inflammatory arthritis. METHODS: We conducted a retrospective cohort study of children aged 1 to 18 years with knee monoarthritis who presented to 1 of 2 pediatric emergency departments located in Lyme endemic areas. We included children who had both a synovial fluid culture and an evaluation for Lyme disease. Septic arthritis was defined as a positive synovial fluid culture or synovial fluid pleocytosis (white blood cell [WBC] ≥40,000 cells/µL) with a positive blood culture. Lyme arthritis was defined as positive Lyme serology without a positive bacterial culture. All other children were considered to have other inflammatory arthritis. We compared the synovial fluid counts by arthritis type. RESULTS: We identified 384 children with knee monoarthritis, of whom 19 (5%) had septic arthritis, 257 (67%) had Lyme arthritis and 108 (28%) had other inflammatory arthritis. Children with other inflammatory arthritis had lower synovial WBC and absolute neutrophil count, as well as percent neutrophils, than those with either Lyme or septic arthritis. There were no significant differences in the synovial fluid WBC, absolute neutrophil count, and percent neutrophils for children with Lyme and septic arthritis. CONCLUSIONS: In Lyme endemic areas, synovial fluid results alone do not differentiate septic from Lyme arthritis. Therefore, other clinical or laboratory indicators are needed to direct the care of patients with knee monoarthritis.

Effect of Age and Sex on Anterior Cruciate Ligament Functional Tests Approximately 6 Months After Anterior Cruciate Ligament Reconstruction.

Purpose: To examine age- and sex-related differences in postoperative functional outcomes at approximately 6 months after anterior cruciate ligament reconstruction (ACLR). Methods: In this study, patients who underwent primary ACLR performed a series of return-to-sport functional tests at 5 to 8 months after surgery. Functional tests included strength tests (knee extensors, knee flexors, hip abductors, and hip extensors), a balance test (Y-balance composite score), and hop tests (single, triple, crossover, and 6-m timed hop tests). Limb symmetry was calculated to compare the reconstructed limb with the uninvolved limb. A 2-way multivariate analysis of covariance was used, and effect size was calculated for data analysis. Results: A total of 176 subjects were included in this study. There were no significant interaction between age and sex on return-to-sport functional tests after ACLR. Also, no main effects of age and sex on return-to-sport functional tests were found in our data. Conclusions: Age and sex do not significantly affect functional test performance after ACLR 6 months postoperatively. Level of Evidence: Level III, retrospective review of prospective cohort study.

Prevalence and Predictors of Concomitant Meniscal Surgery During Pediatric and Adolescent ACL Reconstruction: Analysis of 4729 Patients Over 20 Years at a Tertiary-Care Regional Children's Hospital.

Background: The rate of concomitant meniscal procedures performed in conjunction with anterior cruciate ligament (ACL) reconstruction is increasing. Few studies have examined these procedures in high-risk pediatric cohorts. Hypotheses: That (1) the rates of meniscal repair compared with meniscectomy would increase throughout the study period and (2) patient-related factors would be able to predict the type of meniscal operation, which would differ according to age. Study Design: Cohort study (prevalence); Level of evidence, 2. Methods: Natural language processing was used to extract clinical variables from notes of patients who underwent ACL reconstruction between 2000 and 2020 at a single institution. Patients were stratified to pediatric (5-13 years) and adolescent (14-19 years) cohorts. Linear regression was used to evaluate changes in the prevalence of concomitant meniscal surgery during the study period. Logistic regression was used to determine predictors of the need for and type of meniscal procedure. Results: Of 4729 patients (mean age, 16 ± 2 years; 54.7% female) identified, 2458 patients (52%) underwent concomitant meniscal procedures (55% repair rate). The prevalence of lateral meniscal (LM) procedures increased in both pediatric and adolescent cohorts, whereas the prevalence of medial meniscal (MM) repair increased in the adolescent cohort (P = .02). In the adolescent cohort, older age was predictive of concomitant medial meniscectomy (P = .031). In the pediatric cohort, female sex was predictive of concomitant MM surgery and of undergoing lateral meniscectomy versus repair (P≤ .029). Female sex was associated with decreased odds of concomitant LM surgery in both cohorts (P≤ .018). Revision ACLR was predictive of concomitant MM surgery and of meniscectomy (medial and lateral) in the adolescent cohort (P < .001). Higher body mass index was associated with increased odds of undergoing medial meniscectomy versus repair in the pediatric cohort (P = .03). Conclusion: More than half of the young patients who underwent ACLR had meniscal pathology warranting surgical intervention. The prevalence of MM repair compared with meniscectomy in adolescents increased throughout the study period. Patients who underwent revision ACLR were more likely to undergo concomitant meniscal surgeries, which were more often meniscectomy. Female sex had mixed effects in both the pediatric and adolescent cohorts.

Prevalence and Predictors of Concomitant Meniscal and Ligamentous Injuries Associated With ACL Surgery: An Analysis of 20 Years of ACL Reconstruction at a Tertiary Care Children's Hospital.

BACKGROUND: There is an increasing rate of procedures being performed for concomitant injuries during anterior cruciate ligament (ACL) surgery. Few studies have examined risk factors for these associated injuries in young patients. HYPOTHESIS: There are patient-related factors predictive of concomitant knee pathology that differ between age-based cohorts. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Natural language processing was used to extract clinical variables from available notes of patients undergoing ACL surgery between 2000 and 2020 at a single institution (5174 ACL surgeries; mean age, 17 ± 4 years; 53.1% female; accuracy, >98%). Patients were stratified to pediatric (5-13 years), adolescent (14-19 years), and young adult (20-35 years) cohorts. Logistic regression was used to determine predictors of concomitant injury to the menisci, medial collateral ligament (MCL), posterolateral corner (PLC), and posterior cruciate ligament (PCL). RESULTS: Between 2000 and 2020, 54% of pediatric, 71% of adolescent, and 70% of adult patients had ≥1 concomitant soft tissue injury. In children and adolescents, increased age was consistently predictive of sustaining a concomitant injury (P < .02). Female children had increased odds of concomitant medial meniscal injury, while female adults had decreased odds (P≤ .046). Adolescent and adult female patients had decreased odds of concomitant lateral meniscal injury (P≤ .027). Female children had increased odds of injury to the MCL (P = .015), whereas female children and adolescents had decreased odds of PCL injury (P≤ .044). Adolescents undergoing revision ACL surgery had increased odds of meniscal injury (P≤ .001) and decreased odds of concomitant MCL injury (P = .028). Increased body mass index (BMI) was associated with increased odds of concomitant medial meniscal injury in all cohorts (P≤ .041), lateral meniscal injury in adults (P = .045), and PLC injury in children (P = .016). Contact injuries were associated with increased odds of MCL injury in adolescents (P = .017) and PLC injury in adolescents and adults (P < .014). CONCLUSION: These findings support the hypothesis, as there were multiple factors that significantly affected the risk of concomitant injuries that differed between cohorts. Increased age, BMI, and contact injury history were generally associated with increased odds of sustaining a concomitant injury, whereas female sex and revision ACL surgery had mixed effects. Further studies are essential to investigate the sex-based differences in risk for concomitant injuries and to develop tailored treatment plans that minimize the risk of secondary ACL injury.

Preliminary results of a novel single-stage cartilage restoration technique: particulated juvenile articular cartilage allograft for chondral defects of the patella.

PURPOSE: To evaluate outcomes and magnetic resonance imaging (MRI) findings after use of particulated juvenile cartilage for the treatment of focal Outerbridge grade 4 articular cartilage defects of the patella. METHODS: From 2007 to 2011, 16 patients (2 bilateral) underwent a novel single-stage articular cartilage restoration procedure using particulated juvenile articular cartilage allograft. We enrolled 15 knees (13 patients) in this study. The mean age at surgery was 26.4 ± 9.1 years, and the mean postoperative follow-up was 28.8 ± 10.2 months. A musculoskeletal radiologist evaluated each knee with postoperative MRI for the International Cartilage Repair Society cartilage repair assessment score, graft hypertrophy, bony changes around the graft, and percent fill of the defect. All patients also completed the Knee Injury and Osteoarthritis Outcome Score, International Knee Documentation Committee Subjective Knee Evaluation, and Kujala clinical outcome survey (scale, 0 to 100), as well as the Tegner activity scale and visual analog pain scale (scale, 0 to 10). RESULTS: The mean International Cartilage Repair Society cartilage repair assessment score on MRI was 8.0 ± 2.8, a nearly normal assessment. Of 15 knees, 11 (73%) were found to have normal or nearly normal cartilage repair. Three patients had mild graft hypertrophy whereas 2 had gross graft hypertrophy, 2 of whom required arthroscopic debridement because of symptoms. The mean fill of the defect at follow-up was 89% ± 19.6%, with 12 of 15 knees (80%) showing at least 90% defect coverage. The mean clinical outcome score at follow-up was 73.3 ± 17.6 for the International Knee Documentation Committee evaluation, and the mean scores for each subdomain of the Knee Injury and Osteoarthritis Outcome Score were as follows: 84.2 ± 14.2 for pain, 85.0 ± 12.3 for symptoms and stiffness, 88.9 ± 12.9 for activities of daily living, 62.0 ± 25.1 for sports and recreation, and 60.8 ± 28.6 for quality of life. The median score for the Kujala survey was 79 (range, 55 to 99). The median score on the Tegner activity scale was 5 (range, 3 to 9), and the mean score on the visual analog scale was 1.9 ± 1.4, indicating minimal pain. CONCLUSIONS: Preliminary results suggest that cartilage restoration using particulated juvenile articular cartilage allograft offers a viable option for patients with focal grade 4 articular cartilage defects of the patella.

Anterior cruciate ligament reconstruction femoral tunnel characteristics using an accessory medial portal versus traditional transtibial drilling.

PURPOSE: To evaluate anterior cruciate ligament femoral tunnel characteristics using an accessory medial (AM) portal and transtibial (TT) drilling. METHODS: Ten matched pairs of cadaveric knees underwent arthroscopic AM portal or TT femoral drilling with 8-mm reamers. All knees underwent computed tomography scanning and were evaluated for tunnel aperture area, shape as described by the length of the long and short axes, location of the tunnel relative to the anterior and inferior aspects of the articular surface with the knee in extension, tunnel angle in the coronal and axial planes, and tunnel length. RESULTS: The femoral tunnel aperture area was 50.5 ± 4.8 mm(2) for AM portal drilling and 51.9 ± 4.6 mm(2) for TT drilling (P = .5). The femoral tunnel aperture long axis was 8.5 ± 1.1 mm for AM portal drilling and 9.2 ± 1.3 mm for TT drilling (P = .2), and the short axis was 8.0 ± 0.5 mm for AM portal drilling and 8.0 ± 0.5 mm for TT drilling (P = .8). The femoral tunnel aperture was 5.0 ± 1.4 mm from the anterior wall for AM portal drilling and 9.9 ± 1.7 mm for TT drilling (P < .001), and it was 7.6 ± 2.4 mm from the inferior articular surface for AM portal drilling and 8.9 ± 2.2 mm for TT drilling (P = .2). The femoral tunnel orientation in the coronal plane was 42.1° ± 4.8° for AM portal drilling and 60.9° ± 6.7° for TT drilling (P < .001), and the orientation in the axial plane was 20.9° ± 4.4° for AM portal drilling and 22.7° ± 13.5° for TT drilling (P = .7). The femoral tunnel length was 35.6 ± 2.8 mm for AM portal drilling and 40.3 ± 7.9 mm for TT drilling (P = .1). CONCLUSIONS: The use of an AM portal creates a tunnel more anterior and more horizontal than tunnels created by a TT technique. CLINICAL RELEVANCE: The femoral tunnel characteristics may have an effect on the strain placed on the graft, the graft bending angle, whether enough graft can be placed into the tunnel, and, ultimately, the ability of the body to fully heal the graft.