Magnetic Resonance Imaging Indirect Signs for Anterior Instability of the Lateral Meniscus in Pediatric and Adolescent Patients.

BACKGROUND: Anterior instability (AI) of the LM is potentially debilitating in young patients. The use of magnetic resonance imaging (MRI) to diagnose AI is limited due to the lack of reliable and accurate MRI findings. The ability to identify AI preoperatively would potentially improve the diagnosis and treatment of this pathology. This study presents a novel MRI finding ("phantom sign") for the detection of AI of the LM and demonstrates its reliability and accuracy. METHODS: Three independent blinded reviewers performed retrospective review of preoperative MRI for all patients who underwent LM repair between July 1, 2019, and March 31, 2022, at a single center. Positive phantom sign was defined as abnormal signal intensity on MRI of the anterior horn of the LM on the coronal sequence at the anterior tibial insertion of the anterior cruciate ligament (ACL). Preoperative MRI was also evaluated for other signs of LM anterior instability. Intrarater and inter-rater reliability was assessed for rater scoring of presence of pathology on MRI. Predictive ability of each imaging finding with at least good (ICC 0.6 or above) reliability was also evaluated based on documented intraoperative findings. RESULTS: Fifty-five preoperative MRIs of arthroscopically treated LM tears were reviewed. Median age was 15 years (range 6 to 20), and 21 patients (38.2%) were female. Twenty-seven patients (49.1%) had a discoid meniscus. LM AI was present on arthroscopy for 25 knees (45.45%), and among these, 21 had discoid morphology. Interrater reliability was substantial for phantom sign (ICC 0.71, 97.5% CI: 0.55-0.82), posterior displacement (ICC 0.71, 97.5% CI: 0.55-0.82), and posterior "megahorn" (ICC 0.76, 97.5% CI: 0.62-0.85). On predictive analysis, phantom signs were 98% sensitive and 76.7% specific for LM AI. Posterior displacement and posterior megahorn were specific for AI (both 93.34%), though with limited sensitivity (32% and 28.6%, respectively). CONCLUSIONS: Phantom sign is a reliable and sensitive MRI finding for anterior instability, even in the absence of frank displacement on preoperative MRI. A positive finding should prompt a thorough arthroscopic evaluation of the anterior horn of the LM. LEVEL OF EVIDENCE: Level III-case control study.

Reliability of MRI Interpretation of Discoid Lateral Meniscus: A Multicenter Study.

Background: Discoid lateral meniscus (DLM) has a varied and complex morphology that can be challenging to assess and treat. Preoperative magnetic resonance imaging (MRI) is frequently used for diagnosis and surgical planning; however, it is not known whether surgeons are reliable and accurate in their interpretation of MRI findings when defining the pathomorphology of DLM. Hypothesis: Surgeons experienced in treating DLM are able to reliably interpret DLM pathology using MRI. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Knee MRI scans from 44 patients (45 knees) were selected from a pool of surgically treated patients with DLM. Five reviewers (fellowship-trained pediatric sports medicine surgeons) performed independent review of each MRI scan using the PRiSM Discoid Meniscus Classification. Inter- and intraobserver reliability of the rating factors-primary (width, height, presence of peripheral instability or tear) and secondary (location of instability or tear, tear type)-was assessed using the Fleiss κ coefficient, designed for multiple readers with nominal variables (fair reliability, 0.21-0.40; moderate, 0.41-0.60; substantial, 0.61-0.80; excellent, 0.81-1.00). Reliability is reported as κ (95% CI). Results: Interobserver reliability in assessing most primary and secondary characteristics ranged from substantial (meniscal width) to moderate (peripheral instability, anterior instability, posterior instability, and posterior tear). Intraobserver reliability for most characteristics ranged from substantial (peripheral instability, presence of tear, anterior instability, posterior instability, and posterior tear) to moderate (meniscal width, anterior tear, and tear type). Notable exceptions were presence of tear, anterior tear, and tear type-all with fair interobserver reliability. Height had poor interobserver reliability and fair intraobserver reliability. Conclusion: Orthopaedic surgeons reliably interpret MRI scans using the PRiSM Discoid Meniscus Classification for the majority of DLM characteristics but vary in their assessment of height and presence and type of tear. MRI evaluation may be helpful to diagnose discoid by width and identify the presence of instability: 2 major factors in the decision to proceed with surgery. Arthroscopic evaluation should be used in conjunction with MRI findings for complete DLM diagnosis.

Patellar Sleeve Avulsion Fracture Repair: Suture Anchor Technique With Suture Cerclage Augmentation.

Patella sleeve fractures are rare injuries that occur in pediatric patients. For minimally displaced fractures, nonoperative treatment with immobilization is possible. When fractures are displaced, surgical repair is indicated. Previously described operative techniques include transosseous sutures and tension band wiring. We describe a surgical technique to repair distal pole and patella sleeve avulsion fractures in pediatric patients using intraosseous suture anchors with suture cerclage augmentation.

Discoid Meniscus.

Discoid meniscus is the most common congenital variant of the meniscus. Its variability in pathology leads to a spectrum of clinical presentations in patients. Treatment must be tailored to the specific pathology of the discoid meniscus. Imaging studies such as radiographs and magnetic resonance imaging can be useful in confirming the diagnosis, but may be the most accurate in determining specific pathology. Thorough intraoperative evaluation of the discoid is critical to appropriate surgical management. Rim preservation and repair is preferred to prevent degenerative changes in the knee.

Reliability of a New Arthroscopic Discoid Lateral Meniscus Classification System: A Multicenter Video Analysis.

BACKGROUND: The discoid lateral meniscus (DLM) is one of the most common congenital anomalies of the knee. The pathomorphology of DLM varies. Current classification systems are inadequate to describe the spectrum of abnormality. PURPOSE: A study group of pediatric orthopaedic surgeons from 20 academic North American institutions developed and tested the reliability of a new DLM classification system. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: After reviewing existing classifications, we developed a comprehensive DLM classification system. Four DLM features were evaluated: meniscal width, meniscal height, peripheral stability, and meniscal tear. Stepwise arthroscopic examination using anteromedial and anterolateral viewing portals was established for evaluating these features. Three senior authors who were not observers selected 50 of 119 submitted videos with the best clarity and stepwise examination for reading. Five observers performed assessments using the new classification system to assess interobserver reliability, and a second reading was performed by 3 of the 5 observers to assess intraobserver reliability using the Fleiss κ coefficient (fair, 0.21-0.40; moderate, 0.41-0.60; substantial, 0.61-0.80; excellent, 0.81-1.00). RESULTS: Interobserver reliability was substantial for most rating factors: meniscal width, meniscal height, peripheral stability, tear presence, and tear type. Interobserver reliability was moderate for tear location. Intraobserver reliability was substantial for meniscal width and meniscal height and excellent for peripheral stability. Intraobserver agreement was moderate for tear presence, type, and location. CONCLUSION: This new arthroscopic DLM classification system demonstrated moderate to substantial agreement in most diagnostic categories analyzed.

ACL Growth With Age in Pediatric Patients: An MRI Study.

BACKGROUND: There is limited knowledge of morphologic changes of the anterior cruciate ligament (ACL) during childhood. The purpose of the study is to describe normal ACL growth in pediatric patients. METHODS: We performed retrospective review of patients under 19 years of age with at least 2 serial magnetic resonance imaging (MRI) examinations of the same knee without ACL tear. The parameters measured included length of the ACL, width of the ACL in sagittal and coronal planes, physeal status, ACL-tibial inclination angle, Notch Width Index, ACL tibial attachment width and midpoint, and anterior to posterior length and height of the tibial epiphysis. Pearson correlation coefficients were calculated to determine the strength of correlation of each parameter relative to age. Growth curves were calculated for individual parameters, producing a predictive model for growth of the ACL over time. RESULTS: One hundred forty-seven patients (365 MRIs) were included. The average age at initial MRI was 12.2 years (range: 1.2 to 18.4 y). The Pearson correlation coefficient for each parameter was statistically significant relative to age. Younger patients had more oblique, anteriorly attached ACLs. Three distinct phases of growth were observed: patients age 1.5 to 5.75 years average 2.25 mm of growth per year; patients aged 6 to 11.5 average 1.46 mm of growth per year; growth slows at age 11.75, stopping by 18.5 years. The growth model for ACL sagittal width increased 0.45 mm/y from age 1.5 to 14.5 after which it plateaus, whereas coronal width increased 0.22 mm/y from age 1.5 to 18.75. CONCLUSIONS: In the pediatric patient, the ACL grows in length and width in a predictable manner until age 18. This model aids clinicians in predicting normal ACL parameters for anatomic reconstruction procedures in the skeletally immature patient. LEVEL OF EVIDENCE: Level IV.

Postoperative Pain After Surgical Treatment of Ankle Fractures: A Prospective Study.

BACKGROUND: Postoperative pain after fixation of ankle fractures has a substantial effect on surgical outcome and patient satisfaction. Patients requiring large amounts of narcotics are at higher risk of long-term use of pain medications. Few prospective studies investigate patient pain experience in the management of ankle fractures. METHODS: We prospectively evaluated the pain experience in 63 patients undergoing open reduction and internal fixation of ankle. The Short-Form McGill Pain Questionnaire was administered preoperatively and postoperatively (PP) at 3 days (3dPP) and 6 weeks (6wPP). Anticipated postoperative pain (APP) was recorded. RESULTS: No significant differences were found between PP, APP, and 3dPP; however, 6wPP was markedly lower. Significant correlations were found between PP and APP and between preoperative and postoperative Short-Form McGill Pain Questionnaire scores. PP and APP were independent predictors of 3dPP; however, only APP was predictive of 6wPP. Sex, age, and inpatient versus outpatient status were not notable factors. No statistically significant differences were found in pain scores between fracture types. CONCLUSIONS: Both preoperative pain severity and anticipated postoperative pain are predictive of postoperative pain levels. Orthopaedic surgeons should place a greater focus on the postoperative management of patient pain and expectations after surgical procedures.

Nonoperative management of stable pediatric osteochondritis dissecans of the capitellum: predictors of treatment success.

BACKGROUND: Osteochondritis dissecans (OCD) of the capitellum is a rare but potentially debilitating condition. We sought to determine the healing potential of stable capitellar OCD treated nonoperatively, as well as factors predictive of successful nonoperative management. METHODS: We performed a retrospective review of patients younger than 19 years who presented with stable OCD of the capitellum and were treated nonoperatively for a minimum of 2 months. The average clinical and radiographic follow-up period was 12.1 months (range, 3.1-63.7 months). A multivariable logistic regression model was used to determine independent predictors of healing. RESULTS: The study included 89 patients (93 elbows), including 49 male patients (55%); the mean age was 12.7 years (range, 8.9-18.6 years). Of the 93 elbows, 50 (53.8%) had successfully healed at a mean of 8.3 months. The symptom duration was significantly shorter in the healing group than the nonhealing group (5.3 ± 4.4 months vs 8.8 ± 9.0 months, P = .02). There were no significant differences in age, physeal status, sex, hand dominance, or sport. Hefti stage I lesions had a higher rate of healing (64.3%) than stage II (31.4%, P = .004), as did OCDs without cyst-like lesions (CLLs, 62.0%) compared with those with CLLs (20.8%, P = .001). The normalized lesion area was significantly larger in the nonhealing group (26.9% vs 18.6%, P < .001). A smaller normalized area and the absence of CLLs were independent predictors of healing. CONCLUSIONS: Over half of stable capitellar OCD lesions have the potential to heal with activity restriction. Smaller lesions without CLLs are more likely to heal with nonoperative treatment.