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.

Tarsal Navicular Bone Stress Injuries: A Multicenter Case Series Investigating Clinical Presentation, Diagnostic Approach, Treatment, and Return to Sport in Adolescent Athletes.

BACKGROUND: Tarsal navicular bone stress injuries (BSIs) are considered "high risk" because of prolonged healing times and higher rates of nonunion in adult populations but, to our knowledge, have not been comprehensively examined in adolescent athletes. PURPOSE: To describe the characteristics of tarsal navicular BSIs in adolescents. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A retrospective analysis of patients aged 10 to 19 years with a radiographically diagnosed tarsal navicular BSI was performed at 8 academic centers over a 9-year study period. Age, sex, body mass index (BMI), primary sport, physical examination findings, imaging, treatment, surgical technique, return-to-sport time, and complications were analyzed. RESULTS: Among 110 patients (mean age, 14.7 ± 2.7 years; 65% female), common primary sports were cross-country/track and field (29/92 [32%]) and gymnastics/dance (25/92 [27%]). Grade 4 BSIs were identified in 44% (48/110) of patients, with fracture lines present on radiography or magnetic resonance imaging. Nonoperative treatment (mean age, 14.4 ± 2.6 years), consisting of protected weightbearing and either a protective boot (69/88 [78%]) or a cast (19/88 [22%]), was trialed in all patients and was successful in 94 patients (85%). Operative treatment (mean age, 17.1 ± 1.4 years) was ultimately pursued for 16 patients (15%). Patients who required surgery had a higher BMI and a higher percentage of fracture lines present on imaging (nonoperative: 36/94 [38%]; operative: 14/16 [88%]). The median time to return to weightbearing, running, and full sport was significantly longer in duration for the operative group than the nonoperative group (P <.05). Complications associated with surgery included 1 case each of delayed union, nonunion, and painful implants, the latter of which required secondary surgery. CONCLUSION: Adolescent tarsal navicular BSIs were identified most commonly in female patients in leanness sports. Adolescents who required surgery were more likely to be older, have higher BMIs, and have grade 4 BSIs, and they returned to sport within a median of 5 months after single- or double-screw fixation with a low risk of postoperative complications. A better understanding of the presenting signs and symptoms and appropriate diagnostic imaging of navicular BSIs may lead to an earlier diagnosis and improved outcomes.

Medial Discoid Meniscus in Children: A Multicenter Case Series of Clinical Features and Operative Results.

BACKGROUND: The discoid medial meniscus is a rare congenital anomaly of the knee. The literature is limited to small case series. PURPOSE/HYPOTHESIS: Our purpose is to report the clinical manifestations and operative treatments of discoid medial menisci in children from multiple centers in North America. We hypothesized that symptoms and signs, arthroscopic findings, surgical treatments, and outcomes are similar to those for symptomatic discoid lateral menisci. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A retrospective review identified patients with a diagnosed discoid medial meniscus confirmed at surgery across 8 children's hospitals between January 2000 and June 2021. The literature on discoid lateral menisci was reviewed and summarized for comparison. RESULTS: A total of 21 patients (9 female, 12 male) with 22 discoid medial menisci were identified. The mean ± SD age at the time of diagnosis was 12.8 ± 3.8 years. The most common symptoms and signs were locking and/or clunking, present in 12 of 22 knees (55%), similar to that reported in patients with discoid lateral menisci. Twelve discoid medial menisci were complete (55%); 8, incomplete (36%); and 2, indeterminate (9%). Tears were present in 13 knees, most commonly horizontal cleavage (54%). Five discoid medial menisci were unstable (23%): 3 for posterior tears and 2 for rim insufficiency. All 22 knees underwent arthroscopic saucerization, and of the 13 torn menisci, 7 (54%) were repaired. The median follow-up was 24 months (range, 2-82 months). Four knees underwent reoperation. All knees that required reoperation had undergone repair for a posteriorly located tear. There was a significant association between operative repair and need for reoperation (P = .0048). High rates of peripheral instability were also noted in case series of patients with discoid lateral menisci. CONCLUSION: Patient presentations and treatments for those with discoid medial menisci were similar to those reported for patients with discoid lateral menisci. Knees with discoid medial menisci also demonstrated instability attributed to peripheral insufficiency and posterior tears. Tears were present in over half of knees with discoid medial menisci, and reoperation was more common in knees that underwent repair of tears than those without repair.

Meniscus Repair in Pediatric Athletes.

Meniscus tears are common in the pediatric population, typically occur after noncontact injuries, and can be diagnosed clinically with MRI confirmation. Surgery should be offered to patients with loss of range of motion, persistent symptoms, or displaced/complex tears. Given poor long-term outcomes reported after meniscectomy, repair should be attempted when possible as pediatric menisci are well vascularized and have better outcomes after repair than their adult counterparts. The location of the tear is an important determining factor when deciding on the type of repair to use. Pediatric meniscus repair techniques will be discussed noting differences between pediatric and adult procedures. Further studies are needed to explore the role of biologics and define postoperative protocols.

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.

Treatment Decisions in Pediatric Sports Medicine: Do Personal and Professional Bias Affect Decision-Making?

BACKGROUND: Personal and professional biases can affect decision-making regarding important issues in pediatric sports medicine. Gaining insight into the opinions of health care professionals who specialize in pediatric sports medicine will provide information that may be useful for directing ongoing research in this field. HYPOTHESIS: It was hypothesized that surgeons would demonstrate bias toward early surgical intervention versus nonsurgeons. In addition, it was hypothesized that youth sports medicine professionals who were parents of a child with a previous major sports injury or concussion would be less likely to allow their child to play American tackle football or return to football after a concussion. STUDY DESIGN: Cross-sectional study. METHODS: An online survey was provided to the active members of the Pediatric Research in Sports Medicine Society. We used both professional background information and responses to questions related to personal experiences with youth sports injuries to determine potential factors associated with underlying biases. Survey responses among subgroups were compared using the Fisher exact test. The Pearson correlation coefficient was used to evaluate years in practice versus opioid use. RESULTS: Of the survey participants, 62.5% were pediatric surgeons, and 37.5% represented different nonsurgical youth sports medicine professions. Surgeons were less likely than nonsurgeons to agree to allow their child to return to football after sustaining a concussion and completing a concussion protocol (48% vs 76%, P = .013). Surgeons were more likely than nonsurgeons to agree to both elective shoulder stabilization after a first-time dislocation and elective drilling of a stable knee osteochondritis dissecans (OCD) before nonoperative treatment (41% vs 10%, P = .003 and 52% vs 23%, P = .013, respectively). Those who reported having a child with a concussion history were more likely to support him or her returning to football after a concussion (65% vs 33%, P = .026). CONCLUSION: Surgeons were more likely to favor elective shoulder-stabilization surgery after a first-time dislocation and drilling of a stable knee OCD instead of nonoperative management. Personal experience of having a child who sustained a major sports injury or concussion did not demonstrate a bias against participation in football or return to football after a concussion.

MR Imaging of Osteoid Osteoma: Pearls and Pitfalls.

Osteoid osteoma (OO) is a benign bone neoplasm consisting of a central prostaglandin-secreting nidus surrounded by a zone of reactive sclerosis. The diagnosis is suspected in children and young adults with longstanding nighttime pain that is relieved by salicylates or nonsteroidal anti-inflammatory drugs. Early studies suggested that computed tomography had a higher sensitivity and specificity in the diagnosis of OO compared to magnetic resonance imaging (MRI). More recent literature suggests MRI done with dynamic postcontrast imaging to be equal to or slightly better at detecting the nidus of OOs, particularly the ones in atypical locations. Being able to evaluate for OO utilizing MRI is important given that the majority of these lesions occur in younger patients, in whom there is greater concern to limit ionizing radiation. Furthermore, patients with atypical OOs often receive an MRI if radiographs are not suggestive of the diagnosis. Therefore, it is important for radiologists to be aware of the imaging features that can help make the diagnosis on MRI.

Magnetic resonance imaging evaluation of osteoid osteoma: utility of the dark rim sign.

BACKGROUND: While typical patterns of osteoid osteoma have been described on CT, MRI findings can overlap among different diseases, and atypical patterns exist. In this study, we assessed the presence of a novel dark rim sign and its utility in the MRI diagnosis of osteoid osteoma. OBJECTIVE: The purpose of this retrospective study was to assess the utility of the dark rim sign seen on MRI in children with osteoid osteoma. MATERIALS AND METHODS: MRI studies from 36 pediatric patients with osteoid osteoma and a control group of patients with either osteomyelitis or stress fracture were analyzed and then compared for the presence of the dark rim sign. Patients from the osteoid osteoma group were further divided based on nidus location and evaluated for the presence of the dark rim sign. RESULTS: The relationship between the dark rim sign and osteoid osteoma was statistically significant (P<0.001). A dark rim sign was identified in 25 of the 36 patients with osteoid osteoma. None of the control patients had a dark rim sign. The dark rim sign had 69.4% sensitivity, 100% specificity, 100% positive predictive value and 72.5% negative predictive value for detecting osteoid osteoma. The relationship between dark rim sign and nidus location was statistically significant (P<0.001) such that endosteal and medullary osteoid osteomas were more likely to have a dark rim sign than intracortical osteoid osteomas. CONCLUSION: When the nidus of an osteoid osteoma is in an endosteal or medullary location, the dark rim sign may aid in the diagnosis.

Single stage en bloc resection of a recurrent metastatic osteosarcoma of the pediatric lumbar spine through multiple exposures - a novel approach.

To obtain a wide resection and safe margins in recurrent spine osteosarcoma, the surgical approach can include - posterior only, combined posterior and anterior, and combined posterior and anterior with a return to posterior in multiple stages. In our case, we used a novel approach of multiple extensile exposures circumferentially in a single stage with a single surgical prep. We present the case of a 9-year-old female with a history of metastatic osteosarcoma, who previously underwent an attempted en bloc resection with an L3 corpectomy and left below knee amputation. At 1 year follow-up, she developed a recurrent solitary spine lesion at the previous surgical resection site. An additional attempt at complete surgical resection was performed with a complex en bloc L2, L3, L4 corpectomy with removal of deep spinal implants and anterior and posterior spinal fusion with instrumentation and revision decompressive laminectomy. The patient had a good functional outcome without neurological deficits, except those resulting from resection of involved lumbar nerve roots. At last follow-up of 5 months, there was no local recurrence or distant metastasis. This approach for revision resection of recurrent spinal osteosarcoma can be performed successfully with clean margins in a safe manner.

Can VEPTR(®) control progression of early-onset kyphoscoliosis? A cohort study of VEPTR(®) patients with severe kyphoscoliosis.

BACKGROUND: Kyphoscoliosis is considered a relative contraindication to treatment with the Vertical Expandable Prosthetic Titanium Rib (VEPTR(®); Synthes Inc, Paoli, PA). Nevertheless, patients do present with early-onset kyphoscoliosis and thoracic insufficiency syndrome, and no suitable alternative treatments are currently available. However, it is unclear whether VEPTR(®) is reasonable for treating patients with kyphoscoliosis. QUESTIONS/PURPOSES: We determined whether VEPTR(®) controls progression in patients with kyphoscoliosis and, if so, what methods might be used to improve control of deformity progression in these patients. PATIENTS AND METHODS: We retrospectively reviewed 14 patients who had VEPTR(®) treatment of early-onset kyphoscoliosis. Degrees of kyphosis and scoliosis before, during, and after treatment were measured, and levels of instrumentation, thoracic dimensions, and complications were recorded. Minimum followup was 1.7 years (average, 5.8 years; range, 1.7-12.8 years). RESULTS: While scoliosis was stabilized, kyphosis increased a mean of 22° at last followup. Supple kyphosis became rigid during treatment. Proximal cradle cutout was a recurring problem. Distal anchors placed too proximally had inadequate lever arms to control kyphosis. CONCLUSIONS: Progression of kyphosis can be minimized during VEPTR(®) treatment by early extension of the construct to the second ribs bilaterally, distal extension of hybrid constructs to the pelvis, use of bilateral hybrid VEPTR(®) implants, and use of redesigned VEPTR(®) constructs that enhance fixation at the upper end. While our early results suggest these devices control progression of kyphosis, longer followup with more patients will be required to confirm the concept in these patients.