Osseous and Cartilaginous Trochlear Development in the Pediatric Knee: A Cadaveric Computed Tomography Study.

Background: The anatomy of the trochlea plays a significant role in patellar stability. The developmental anatomy of the trochlea and its relationship to patellar stability remains poorly understood. Purpose: To describe the developmental changes of the osseous and cartilaginous trochlear morphology in skeletally immature specimens. Study Design: Descriptive laboratory study. Methods: A total of 65 skeletally immature cadaveric knees between the ages of 2 months and 11 years were evaluated using computed tomography scans. The measurements in the axial plane of both cartilage and bone include medial, central, and lateral trochlear height; sulcus height; medial and later trochlear facet length; trochlear sulcus angle; patellar sulcus angle; condylar height asymmetry; and trochlear facet asymmetry. Additional measurements included trochlear depth and lateral trochlear inclination angle. In the sagittal plane, measurements included curvilinear trochlear length, direct trochlear length, condylar height, and patellar sulcus angle. Results: Analysis of trochlear morphology using condylar height, condylar height asymmetry, and trochlear depth all increased with increasing age. The osseous and cartilaginous sulcus angles became deeper with age until age 8 and then plateaued. This corresponded with an increase in trochlear depth that also plateaued around age 8. Osseous condylar asymmetry increased with age but flipped from a larger medial condyle to a larger lateral condyle around age 8. The continued growth of the trochlea with age was further demonstrated in all measures in the sagittal view. Conclusion: This cadaveric analysis demonstrated that there is an increase in condylar height as age increased by all measurements analyzed. These changes in condylar height continued to be seen through age 11, suggesting a still-developing trochlea past this age. By age 8, a plateau in sulcus angle, and sulcus depth suggests more proportionate growth after this point. Similar changes in trochlear and patellar shape with age suggests that the 2 structures may affect each other during development. Clinical Relevance: This information can help design, develop, and determine timing of procedures that may alter the anatomy and stabilize the trochlear and patellofemoral joint.

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.

Knee Flexion Angle of Fixation During Anterolateral Ligament Reconstruction or Lateral Extra-articular Tenodesis: A Systematic Review and Meta-analysis of Lateral Extra-articular Reinforcement Techniques Performed in Conjunction With ACL Reconstruction.

Background: Anterolateral ligament reconstruction (ALLR) or lateral extra-articular tenodesis (LET) is being used more frequently in conjunction with anterior cruciate ligament reconstruction (ACLR). However, the knee flexion angle at which fixation of ALLR or LET is performed during the procedure is quite variable based on existing technique descriptions. Purpose/Hypothesis: The purpose of this study was to identify whether flexion angle at the time of ALLR/LET fixation affected postoperative outcomes in a clinical population. It was hypothesized that ALLR/LET fixation at low versus high flexion angles would lead to no statistically significant differences in patient-reported outcome measures and graft failure rates. Study Design: Systematic review; Level of evidence, 4. Methods: The PubMed, Embase, and Cochrane Library databases were searched according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify published clinical studies of ACLR with ALLR/LET in which the knee flexion angle at the time of ALLR/LET was reported. A priori, low flexion was defined as 0° to 30°, and high flexion was defined as 60° to 90°. Studies were excluded if the flexion angle was between 31° and 59° because these angles constituted neither low nor high flexion angles and including them in an analysis of high versus low flexion angle at fixation would have biased the study results toward the null. The overall risk of bias was assessed using the Newcastle-Ottawa Scale. The pooled results of the studies were analyzed using the International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores, along with reported graft failure rates. Results: A total of 32 clinical studies (5230 patients) met inclusion criteria: 22 studies (1999 patients) in the low-flexion group and 10 studies (3231 patients) in the high-flexion group. The median Newcastle-Ottawa Scale score was 6. Comparisons of patients with a low flexion angle versus a high flexion angle demonstrated no differences in the IKDC (P = .84), Lysholm (P = .67), or Tegner (P = .44) scores or in graft failure (3.4% vs 4.1%, respectively; P = .69). Conclusion: The results of this review indicated that ACLR performed in conjunction with ALLR/LET provides good to excellent patient-reported outcomes and low graft failure rates when ALLR/LET fixation is performed in either low or high knee flexion.

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.

Tibial Spine Fractures in the Child and Adolescent Athlete: A Systematic Review and Meta-analysis.

BACKGROUND: Tibial spine fractures (TSFs) are uncommon injuries that may result in substantial morbidity in children. A variety of open and arthroscopic techniques are used to treat these fractures, but no single standardized operative method has been identified. PURPOSE: To systematically review the literature on pediatric TSFs to determine the current treatment approaches, outcomes, and complications. STUDY DESIGN: Meta-analysis; Level of evidence, 4. METHODS: A systematic review of the literature was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) guidelines using PubMed, Embase, and Cochrane databases. Studies evaluating treatment and outcomes of patients <18 years old were included. Patient demographic characteristics, fracture characteristics, treatments, and outcomes were abstracted. Descriptive statistics were used to summarize categorical and quantitative variables, and a meta-analytic technique was used to compare observational studies with sufficient data. RESULTS: A total of 47 studies were included, totaling 1922 TSFs in patients (66.4% male) with a mean age of 12 years (range, 3-18 years). The operative approach was open reduction and internal fixation in 291 cases and arthroscopic reduction and internal fixation in 1236 cases; screw fixation was used in 411 cases and suture fixation, in 586 cases. A total of 13 nonunions were reported, occurring most frequently in Meyers and McKeever type III fractures (n = 6) and in fractures that were treated nonoperatively (n = 10). Arthrofibrosis rates were reported in 33 studies (n = 1700), and arthrofibrosis was present in 190 patients (11.2%). Range of motion loss occurred significantly more frequently in patients with type III and IV fractures (P < .001), and secondary anterior cruciate ligament (ACL) injury occurred most frequently in patients with type I and II fractures (P = .008). No statistically significant differences were found with regard to rates of nonunion, arthrofibrosis, range of motion loss, laxity, or secondary ACL injury between fixation methods (screw vs suture). CONCLUSION: Despite variation in TSF treatment, good overall outcomes have been reported with low complication rates in both open and arthroscopic treatment and with both screw and suture fixation. Arthrofibrosis remains a concern after surgical treatment for TSF, but no significant difference in incidence was found between the analysis groups. Larger studies are necessary to compare outcomes and form a consensus on how to treat and manage patients with TSFs.

Risk Factors for Suboptimal Outcome of FAI Surgery in the Adolescent Patient.

BACKGROUND: Surgical treatment for adolescent patients with femoroacetabular impingement (FAI) is increasing. The purpose of this study was to determine the clinical outcomes of FAI surgery in a multicenter cohort of adolescent patients and to identify predictors of suboptimal outcomes. METHODS: One hundred twenty-six adolescent hips (114 patients < 18 years of age) undergoing surgery for symptomatic FAI were studied from a larger multicenter cohort. The group included 74 (58.7%) female and 52 male hips (41.3%) with a mean age of 16.1 (range 11.3 to 17.8). Clinical outcomes included the modified Harris Hip Score (mHHS), Hip disability and Osteoarthritis Outcome Score (5 domains), and University of California Los Angeles activity score. Failure was defined as revision surgery or clinical failure (inability to reach minimally clinical important differences or patient acceptable symptoms state for the mHHS). Statistical analysis was used to identify factors significantly associated with failure. RESULTS: There was clinically important improvement in all patient-reported outcomes for the overall group, but an 18.3% failure rate. This included a revision rate of 8.7%. Females were significantly more likely than males to be classified as a failure (25.7 vs. 7.7%, P =0.01), in part because of lower preoperative mHHS (59.1 vs. 67.0, P < 0.001). Mild cam deformity (alpha angle <55 degrees) was present in 42.5% of female hips compared with 17.3% male hips. Higher alpha angles were inversely correlated with failure. Alpha angles >63 have a failure rate of 8.3%, between 55 and 63 degrees, 12.0% failure rate, and <55 degrees (mild cam) failure rate of 37.5%. Patients who participated in athletics had a 10.3% failure rate compared with nonathletes at 25.0% ( P =0.03, RR (relative risk) 2.4). CONCLUSIONS: Adolescent patients undergoing surgical treatment for FAI generally demonstrate significant improvement. However, female sex, mild cam deformities, and lack of sports participation are independently associated with higher failure rates. These factors should be considered in surgical decision-making and during patient counseling. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

The Effects of Residual Femoral Deformity on Computed Contact Mechanics in Patients Treated With In Situ Fixation for Slipped Capital Femoral Epiphysis.

OBJECTIVE: In situ fixation for treatment of slipped capital femoral epiphysis (SCFE) can stabilize the epiphysis and prevent further joint deformation but often leaves residual deformity that may adversely affect intra-articular contact mechanics. The purpose of this study was to investigate the relationship between residual deformity and contact mechanics in the post-SCFE hip. METHODS: Patient-specific hip models were created for 19 patients with SCFE treated with in situ fixation. For each model, discrete element analysis was used to compute cumulative acetabular and femoral contact stress exposure during a walking gait cycle. Slip severity was evaluated for each patient using the two-dimensional Southwick angle and a novel three-dimensional (3D) assessment of multiplanar femoral deformity (3D slip angle). RESULTS: Of the SCFE cases, 2/7 mild (Southwick angle ≤30 degrees) had peak cumulative femoral exposures equivalent to that of severe (Southwick angle ≥60 degrees) cases. Severe SCFE cases had higher peak ( P = 0.015) and mean ( P = 0.028) femoral contact stress exposure and lower cumulative femoral contact area ( P = 0.003) than mild (Southwick angle ≤30 degrees) SCFE cases. Mean femoral contact stress exposure was also higher in severe SCFE cases than in moderate SCFE cases ( P = 0.027). Acetabular and femoral contact mechanics metrics typically demonstrated stronger correlations with 3D slip angle than two-dimensional Southwick angle. CONCLUSIONS: Increased slip severity adversely impacts intra-articular femoral contact mechanics. Contact mechanics metrics demonstrate higher correlations with 3D slip angle, indicating that this novel measurement may better describe global deformity and its relationship to intra-articular mechanics; however, the modest strength of these correlations may also imply that global impingement-generating deformity is not the primary factor driving contact mechanics in the post-SCFE hip. CLINICAL RELEVANCE: Greater slip severity adversely impacts contact mechanics in the post-SCFE hip. However, focal regions of high contact stress were seen even in mild SCFE deformities, suggesting some type of deformity correction should be considered even for mild slips to alleviate secondary impingement, address focal incongruities, and reduce osteoarthritis development/progression.

Introducing Skeletally-Mature Anterior Cruciate Ligament Reconstruction Technique Using Reinforcement (SATURN) With Iliotibial Band Autograft.

Anterior cruciate ligament (ACL) injuries are increasingly common in the adolescent age group. Recent literature has endorsed combining ACL reconstruction with lateral extra-articular procedures to minimize residual rotatory knee instability and reduce the risk of reinjury in this age group. This technique describes a single-bundle combined anatomical ACL reconstruction and lateral extra-articular reinforcement performed with a single iliotibial band autograft. Also this technique allows for the ACL reconstruction and lateral extra-articular stabilization to be performed through a single surgical incision while obtaining autograft tissue without disruption of the extensor or hamstring mechanisms.

Comparable Injury to the Indirect Head of the Rectus Femoris During Interportal and Periportal Capsulotomy: A Cadaveric Study.

Background: There is concern for maintaining the integrity of the reflected head of the rectus femoris during arthroscopic hip joint access. Because of the proximity to the indirect head of the rectus femoris (IHRF), capsulotomy technique and capsular closure during routine hip arthroscopy may play a role in postoperative tendinitis. Purpose: To quantify the extent of injury sustained to the IHRF during interportal versus periportal capsulotomy for routine arthroscopic hip joint access. Study Design: Controlled laboratory study. Methods: A cadaveric study was conducted using 20 fresh-frozen cadaveric hips, in which hip joint access through a periportal capsulotomy (n = 10) or interportal capsulotomy (n = 10) was performed. Capsular closure followed by a layered dissection to the capsuloligamentous complex of the hip joint was then performed to localize the IHRF. Suture proximity to the tendon, tendon disruption, and the IHRF footprint was documented to the nearest 0.01 mm using digital calipers. Statistical analysis was performed using unpaired Student t tests. Results: The mean capsulotomy length for the interportal specimens was 19.27 ± 3.25 mm, and the mean medial and lateral capsulotomy length for the periportal specimens was 4.47 ± 1.60 and 4.26 ± 0.89 mm, respectively. There was violation of the tendon in 3 of 10 interportal specimens and 4 of 10 periportal specimens. There was no significant difference in the closest suture measured to the IHRF for specimens with versus without tendon violation, for either interportal or periportal capsulotomy. Conclusion: We found comparable outcomes with regard to violation of the IHRF between interportal and periportal capsulotomy, with no significant difference in suture proximity to the IHRF in specimens with or without tendon violation. There remains no consensus on the ideal method by which to avoid iatrogenic damage to the IHRF. Clinical Relevance: Our findings provide insight that may lead to future advances in surgical care, such that protection of the tendon during routine hip arthroscopy may allow for improved postoperative rehabilitation and strength.

Efficacy of regional anesthesia in hip preservation surgeries: a systematic review.

The purpose of this study was to review the current literature on perioperative pain management in hip arthroscopy, periacetabular osteotomy and surgical hip dislocation. A systematic review of the literature published from January 2000 to December 2022 was performed. Selection criteria included published randomized controlled trials, prospective reviews and retrospective reviews of all human subjects undergoing hip preservation surgery. Exclusion criteria included case reports, animal studies and studies not reporting perioperative pain control protocols. Thirty-four studies included hip arthroscopy in which peripheral nerve blocks were associated with a significant reduction in pain score (P = 0.037) compared with general anesthesia alone. However, no pain control modality was associated with a significant difference in postanesthesia care unit opioid use (P = 0.127) or length of stay (P = 0.251) compared with general anesthesia alone. Falls were the most common complication reported, accounting for 37% of all complications. Five studies included periacetabular osteotomy and surgical hip dislocation in which peripheral nerve blocks were associated with an 18% reduction in pain on postoperative Day 2, a 48% reduction in cumulative opioid use on postoperative Day 2 and a 40% reduction in hospital stay. Due to the low sample size of the periacetabular osteotomy and surgical hip dislocation studies, we were unable to determine the significant difference between the means. Due to significant between-study heterogeneity, additional studies with congruent outcome measures need to be conducted to determine the efficacy of regional anesthesia in hip arthroscopy, periacetabular osteotomy and surgical hip dislocation.

Anterior Displacement of Tibial Spine Fractures: Does Anatomic Reduction Matter?

Background: Operative treatment of displaced tibial spine fractures consists of fixation and reduction of the fragment in addition to restoring tension of the anterior cruciate ligament. Purpose: To determine whether residual displacement of the anterior portion of a tibial spine fragment affects the range of motion (ROM) or laxity in operatively and nonoperatively treated patients. Study Design: Cohort study; Level of evidence, 3. Methods: Data were gathered from 328 patients younger than 18 years who were treated for tibial spine fractures between 2000 and 2019 at 10 institutions. ROM and anterior lip displacement (ALD) measurements were summarized and compared from pretreatment to final follow-up. ALD measurements were categorized as excellent (0 to <1 mm), good (1 to <3 mm), fair (3 to 5 mm), or poor (>5 mm). Posttreatment residual laxity and arthrofibrosis were assessed. Results: Overall, 88% of patients (290/328) underwent operative treatment. The median follow-up was 8.1 months (range, 3-152 months) for the operative group and 6.7 months (range, 3-72 months) for the nonoperative group. The median ALD measurement of the cohort was 6 mm pretreatment, decreasing to 0 mm after treatment (P < .001). At final follow-up, 62% of all patients (203/328) had excellent ALD measurements, compared with 5% (12/264) before treatment. Subjective laxity was seen in 11% of the nonoperative group (4/37) and 5% of the operative group (15/285; P = .25). Across the cohort, there was no association between final knee ROM and final ALD category. While there were more patients with arthrofibrosis in the operative group (7%) compared with the nonoperative group (3%) (P = .49), this was not different across the ALD displacement categories. Conclusion: Residual ALD was not associated with posttreatment subjective residual laxity, extension loss, or flexion loss. The results suggest that anatomic reduction of a tibial spine fracture may not be mandatory if knee stability and functional ROM are achieved.

Outcomes of Adolescent T-condylar Fractures: Kids Do Not Always Make You Look Good.

BACKGROUND: Optimal treatment for pediatric and adolescent T-condylar fractures remains poorly understood. We sought to assess how functional outcomes and range of motion (ROM) after surgical fixation of T-condylar fractures are affected by patient and surgical factors. METHODS: This is a retrospective cohort study of 52 patients with operatively treated T-condylar fractures at a single tertiary pediatric referral center between 2003 and 2021. All patients younger than 18 at the time of injury with a radiographically confirmed diagnosis were included. RESULTS: Fifty-two T-condylar fractures were included, with a mean patient age of 12.9 years (SD, 2.8). The cohort was 65% male. Nine (19%) fractures were open, 46% (24/52) were AO type C2, and 33% (17/52) occurred in skeletally mature individuals. The surgical approach was through olecranon osteotomy in 29% (15/52) of patients, and fixation included anatomically specific plates and screws in 42% (22/52) of patients. In our cohort, 46% (24/52) achieved good outcomes based on Jarvis ROM criteria and 42% (22/52) achieved good to excellent results based on Roberts functional criteria. The median loss of ROM was 58 degrees at 6 weeks, 20 degrees at 3 and 6 months, and 8 degrees at 1 year postoperatively. We observed a complication rate of 54% (28/52). Patients undergoing adult-type plate fixation had better postoperative range of motion at 6 weeks (ROM loss 52 vs. 80 degrees, P =0.03) and 3 months (10 vs. 35 degrees P =0.004) compared with pediatric-type fixation and trended towards better functional outcomes. We did not identify significant differences in functional outcome scores or complication rates with respect to surgical approach or skeletal maturity. CONCLUSIONS: Surgical fixation of pediatric and adolescent T-condylar fractures achieved a good to excellent functional outcome in only a minority of patients (46% Jarvis / 42% Roberts) with a high rate of postoperative complications (54%). Future work is needed to elucidate optimal treatment to minimize complications and achieve the best functional outcomes in these challenging fractures. LEVEL OF EVIDENCE: Level-IV.

Fixation Strategy Does Not Affect Risk of Growth Disturbance After Surgical Treatment of Pediatric Tibial Spine Fracture.

Purpose: To characterize growth abnormalities after surgical treatment of tibial spine fractures and to investigate risk factors for these abnormalities. Methods: A retrospective analysis of children who underwent treatment of tibial spine fractures between January 2000 and January 2019 was performed, drawing from a multicenter cohort among 10 tertiary care children's hospitals. The entire cohort of surgically treated tibial spine fractures was analyzed for incidence and risk factors of growth disturbance. The cohort was stratified into those who were younger than the age of 13 years at the time of treatment in order to evaluate the risk of growth disturbance in those with substantial growth remaining. Patients with growth disturbance in this cohort were further analyzed based on age, sex, surgical repair technique, implant type, and preoperative radiographic measurements with χ2, t-tests, and multivariate logistic regression. Results: Nine patients of 645 (1.4%) were found to have growth disturbance, all of whom were younger than 13 years old. Patients who developed growth disturbance were younger than those without (9.7 years vs 11.9 years, P = .019.) There was no association with demographic factors, fracture characteristics, surgical technique, hardware type, or anatomic placement (i.e., transphyseal vs physeal-sparing fixation) and growth disturbance. Conclusions: In this study, we found an overall low incidence of growth disturbance after surgical treatment of tibial spine fractures. There was no association with surgical technique and risk of growth disturbance. Level of Evidence: Level III, retrospective comparative study.

Effect of Age and Sex on Psychological Readiness and Patient-Reported Outcomes 6 Months After Primary ACL Reconstruction.

Background: Successful return to sport after anterior cruciate ligament (ACL) reconstruction (ACLR) can be affected by a patient's physical and psychological state throughout the rehabilitation process. Purpose: To prospectively compare differences in patients at 6 months after primary ACLR with the ACL-Return to Sport after Injury (ACL-RSI), International Knee Documentation Committee (IKDC) or pediatric (Pedi)-IKDC, Hospital for Special Surgery Pediatric Functional Activity Brief Scale (Pedi-FABS), and Patient-Reported Outcomes Measurement Information System-Psychological Stress Experiences (PROMIS-PSE) scores. Study Design: Prospective cohort study; Level of evidence, 2. Methods: Patients enrolled were 8 to 35 years old who underwent primary ACLR and had their 6-month follow-up appointments between December 2018 and March 2020. Patients were divided into 3 age groups as follows: (1) preadolescents (10-14 years); (2) adolescents (15-18 years); and (3) adults (>18 years). Outcomes on the ACL-RSI, IKDC/Pedi-IKDC, Pedi-FABS, and PROMIS-PSE were compared according to age group, graft type (hamstring, patellar tendon, quadriceps, or iliotibial band autograft), and sex. Results: A total of 176 patients (69 male, 107 female), with a mean age of 17.1 ± 3.1 years were included in the study. The mean ACL-RSI scores were significantly different among age groups (preadolescents, 75 ± 18.9; adolescents, 61.5 ± 20.4; and adults, 52.5 ± 19.8 [P < .001]) and graft types (P = .024). The IKDC and PROMIS-PSE scores were also significantly different among age groups (P < .001 and P = .044, respectively) and graft types (P = .034 and P < .001, respectively), with the iliotibial graft and the younger age group performing the best. There was no significant difference in the Pedi-FABS either by age group (P = .127) or graft type (P = .198). Female patients had lower ACL-RSI scores and higher (worse) scores on PROMIS-PSE than their male counterparts (P = .019 and P < .001, respectively), with no sex-based differences on IKDC or Pedi-FABS scores. The ACL-RSI and IKDC were positively correlated (Spearman r = 0.57; P < .001), while the ACL-RSI and PROMIS-PSE were negatively correlated (Pearson r = -0.34; P < .001). Conclusion: This study suggests that psychological profiles and subjective perceptions of knee function 6 months after ACLR may vary in patients of different ages and between the sexes. Preadolescent patients had better scores on a majority of patient-reported outcomes compared with adolescent and adult patients.

Screws or Sutures? A Pediatric Cadaveric Study of Tibial Spine Fracture Repairs.

BACKGROUND: Tibial spine fractures are common in the pediatric population because of the biomechanical properties of children's subchondral epiphyseal bone. Most studies in porcine or adult human bone suggest that suture fixation performs better than screw fixation, but these tissues may be poor surrogates for pediatric bone. No previous study has evaluated fixation methods in human pediatric knees. PURPOSE: To quantify the biomechanical properties of 2-screw and 2-suture repair of tibial spine fracture in human pediatric knees. STUDY DESIGN: Controlled laboratory study. METHODS: Cadaveric specimens were randomly assigned to either 2-screw or 2-suture fixation. A standardized Meyers-Mckeever type 3 tibial spine fracture was induced. Screw-fixation fractures were reduced with two 4.0-mm cannulated screws and washers. Suture-fixation fractures were reduced by passing 2 No. 2 FiberWire sutures through the fracture fragment and the base of the anterior cruciate ligament. Sutures were secured through bony tunnels over a 1-cm tibial cortical bridge. Each specimen was mounted at 30° of flexion. A cyclic loading protocol was applied to each specimen, followed by a load-to-failure test. Outcome measures were ultimate failure load, stiffness, and fixation elongation. RESULTS: Twelve matched pediatric cadaveric knees were tested. Repair groups had identical mean (8.3 years) and median (8.5 years) ages and an identical number of samples of each laterality. Ultimate failure load did not significantly differ between screw (mean ± SD, 143.52 ± 41.9 7 N) and suture (135.35 ± 47.94 N) fixations (P = .760). Screws demonstrated increased stiffness and decreased elongation, although neither result was statistically significant at the .05 level (21.79 vs 13.83 N/mm and 5.02 vs 8.46 mm; P = .076 and P = .069, respectively). CONCLUSION: Screw fixation and suture fixation of tibial spine fractures in human pediatric tissue were biomechanically comparable. CLINICAL RELEVANCE: Suture fixations are not biomechanically superior to screw fixations in pediatric bone. Pediatric bone fails at lower loads, and in different modes, compared with adult cadaveric bone and porcine bone. Further investigation into optimal repair is warranted, including techniques that may reduce suture pullout and "cheese-wiring" through softer pediatric bone. This study provides new biomechanical data regarding the properties of different fixation types in pediatric tibial spine fractures to inform clinical management of these injuries.

Quantitative MRI Biomarkers to Predict Risk of Reinjury Within 2 Years After Bridge-Enhanced ACL Restoration.

BACKGROUND: Quantitative magnetic resonance imaging (qMRI) methods were developed to establish the integrity of healing anterior cruciate ligaments (ACLs) and grafts. Whether qMRI variables predict risk of reinjury is unknown. PURPOSE: To determine if qMRI measures at 6 to 9 months after bridge-enhanced ACL restoration (BEAR) can predict the risk of revision surgery within 2 years of the index procedure. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Originally, 124 patients underwent ACL restoration as part of the BEAR I, BEAR II, and BEAR III prospective trials and had consented to undergo an MRI of the surgical knee 6 to 9 months after surgery. Only 1 participant was lost to follow-up, and 4 did not undergo MRI, leaving a total of 119 patients for this study. qMRI techniques were used to determine the mean cross-sectional area; normalized signal intensity; and a qMRI-based predicted failure load, which was calculated using a prespecified equation based on cross-sectional area and normalized signal intensity. Patient-reported outcomes (International Knee Documentation Committee subjective score), clinical measures (hamstring strength, quadriceps strength, and side-to-side knee laxity), and functional outcomes (single-leg hop) were also measured at 6 to 9 months after surgery. Univariate and multivariable analyses were performed to determine the odds ratios (ORs) for revision surgery based on the qMRI and non-imaging variables. Patient age and medial posterior tibial slope values were included as covariates. RESULTS: In total, 119 patients (97%), with a median age of 17.6 years, underwent MRI between 6 and 9 months postoperatively. Sixteen of 119 patients (13%) required revision ACL surgery. In univariate analyses, higher International Knee Documentation Committee subjective score at 6 to 9 months postoperatively (OR = 1.66 per 10-point increase; P = .035) and lower qMRI-based predicted failure load (OR = 0.66 per 100-N increase; P = .014) were associated with increased risk of revision surgery. In the multivariable model, when adjusted for age and posterior tibial slope, the qMRI-based predicted failure load was the only significant predictor of revision surgery (OR = 0.71 per 100 N; P = .044). CONCLUSION: Quantitative MRI-based predicted failure load of the healing ACL was a significant predictor of the risk of revision within 2 years after BEAR surgery. The current findings highlight the potential utility of early qMRI in the postoperative management of patients undergoing the BEAR procedure.

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.

Preoperative Risk Factors for Subsequent Ipsilateral ACL Revision Surgery After an ACL Restoration Procedure.

BACKGROUND: Anterior cruciate ligament (ACL) revision surgery is challenging for both patients and surgeons. Understanding the risk factors for failure after bridge-enhanced ACL restoration (BEAR) may help with patient selection for ACL restoration versus ACL reconstruction. PURPOSE: To identify the preoperative risk factors for ACL revision surgery within the first 2 years after BEAR. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Data from the prospective BEAR I, II, and III trials were used to determine the preoperative risk factors for ACL revision surgery. All patients with a complete ACL tear (aged 13-47 years, depending on the trial), who met all other inclusion/exclusion criteria and underwent a primary BEAR procedure within 30 to 50 days from the injury (dependent on the trial), were included. Demographic data (age, sex, body mass index), baseline patient-reported outcomes (International Knee Documentation Committee [IKDC] subjective score, Marx activity score), preoperative imaging results (ACL stump length, notch size, tibial slope), and intraoperative findings (knee hyperextension, meniscal status) were evaluated to determine their contribution to the risk of ipsilateral ACL revision surgery. RESULTS: A total of 123 patients, with a median age of 17.6 years (interquartile range, 16-23 years), including 67 (54%) female patients, met study criteria. Overall, 18 (15%) patients required ACL revision surgery in the first 2 years after the BEAR procedure. On bivariate analyses, younger age (P = .011), having a contact injury at the time of the initial tear (P = .048), and increased medial tibial slope (MTS; P = .029) were associated with a higher risk of ipsilateral revision surgery. Multivariable logistic regression analyses identified 2 independent predictors of revision: patient age and MTS. The odds of ipsilateral revision surgery were decreased by 32% for each 1-year increase in age (odds ratio, 0.684 [95% CI, 0.517-0.905]; P = .008) and increased by 28% for each 1° increase in MTS (odds ratio, 1.280 [95% CI, 1.024-1.601]; P = .030). Sex, baseline IKDC or Marx score, knee hyperextension, and meniscal status were not significant predictors of revision. CONCLUSION: Younger age and higher MTS were predictors of ipsilateral ACL revision surgery after the BEAR procedure. Younger patients with higher tibial slopes should be aware of the increased risk for revision surgery when deciding to undergo ACL restoration.

Moderate and High Sport Specialization Level in Ice Hockey Athletes Is Associated With Symptomatic Cam Deformity.

BACKGROUND: There is a known association between ice hockey and cam deformity in growing athletes. Similarly, the association between sport specialization and overuse injury in youth athletes has been well established. Limited research exists examining the relationship between cam deformity and sport specialization. HYPOTHESIS/PURPOSE: Our hypothesis was that there would be a positive association with cam deformity and sport specialization category. STUDY DESIGN: Retrospective chart review and cross-sectional questionnaire study. LEVEL OF EVIDENCE: Level 4. METHODS: Study participants included athletes aged 15 to 25 years with symptomatic femoroacetabular impingement (FAI) and considered ice hockey as their primary sport. All participants had completed Dunn lateral radiographs or hip magnetic resonance imaging as part of their clinical evaluation. All participants completed a survey regarding sport specialization level. Multivariable linear regression analysis controlling for sex was used to analyze the association between degree of sport specialization, age of sport specialization, position played, and level played. Comparisons in radiographic parameters across ice hockey groups were conducted using Student t tests and chi-square tests. RESULTS: Sixty-six ice hockey participants made up the cohort. The majority reported high sport specialization (41/66, 62%). The mean age of sport specialization was 10.7 years (SD 3.5). Participants with moderate specialization had 25 times the odds of a cam deformity (odds ratio [OR] 25.2; 95% CI 1.5-410.7; P = 0.02) and those with high specialization had 9 times the odds of cam deformity (OR 9.3; 95% CI 1.2-74.2; P = 0.04) compared with those with a low degree of specialization, controlling for patient sex. No association was detected between the age of specialization and the likelihood of cam deformity when controlling for patient sex. CONCLUSION: Level of sport specialization was associated with a cam deformity in this cohort of youth ice hockey athletes. CLINICAL RELEVANCE: This study suggests that an association exists.

Lyme Arthritis in the Pediatric Knee: Clinical and Magnetic Resonance Imaging Differentiators.

Lyme disease is the most prevalent tick-borne illness in the United States, especially endemic in the Northeast and Upper Midwest. Distinguishing Lyme arthritis (LA), the most common manifestation of the disease in children, from septic arthritis (SA) can be challenging because of overlap in clinical presentations. This study examined the role of magnetic resonance imaging (MRI) as an adjunct to clinical and laboratory features used to differentiate between LA and SA in children and adolescents. Methods: The medical records and MRI scans of children who presented between 2009 and 2019 with an acute knee effusion ultimately diagnosed as LA or SA were retrospectively reviewed. Data collection included clinical information on the modified Kocher criteria (weight-bearing, fever, blood serology including white blood-cell [WBC] count, C-reactive protein [CRP], and erythrocyte sedimentation rate [ESR]), MRI findings, and serology confirmation of LA or bacterial SA. A total of 87 cases of confirmed LA and 9 cases of SA were identified. Results: The 2 cohorts had substantial clinical overlap with regard to the ability to bear weight, fever, and joint aspirate WBC count. Differences between the 2 groups in several MRI characteristics, specifically vastus lateralis myositis, subcutaneous edema, and lymphadenopathy, were significant. A multivariate analysis demonstrated that weight-bearing, CRP of <3 mg/L, absence of subcutaneous edema, myositis of multiple muscles including the vastus lateralis, and lymphadenopathy were predictive of LA. Conclusions: LA should be strongly suspected in endemic areas of the United States when children present with a knee effusion. The addition of MRI criteria to clinical and laboratory findings significantly improved the predictive value for identifying LA. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.