Diagnostic Value of Ultrasound in Children with Discoid Lateral Meniscus Using Either an Intracavitary Convex Array Probe or a Linear Array Probe

Abstract

This prospective study aimed to assess the usefulness of an intracavitary convex array probe (ICAP) in visualizing the lateral meniscus (LM) and improving the diagnostic utility of ultrasound (US) when diagnosing or screening for discoid lateral meniscus (DLM) in children. We included 105 knees (66 patients) that had symptomatic or asymptomatic DLM. We extracted and retrospectively reviewed data regarding patient demographics, medical records, magnetic resonance imaging (MRI), ultrasonographic features and arthroscopic findings. The inner edge of the LM visualized using an ICAP was significantly clearer than that visualized using a linear array probe, and the difference was significant (p < 0.01). The edges were better visualized in patients aged <8 y than in those aged >8 y, and the difference was significant (p < 0.001). The average widths of the LM body using an ICAP and MRI were 19.85 § 3.63 and 24.46 § 4.94 mm, respectively, and the wider the meniscal width, the greater was the deviation between the US and MRI measurements, which were positively correlated (r = 0.612, p < 0.001). With the use of MRI measurements and an ICAP, meniscal widths in poorly visualized LMs were greater than those in clearly visualized LMs, but this difference was not significant (p = 0.161). US scans using an ICAP and MRI were highly consistent in assessing the shape of the menisci (k = 0.849, p < 0.001). US scan using an ICAP is a non-invasive, convenient and low-cost modality for diagnosing or screening for DLM in the pediatric population, especially in children aged <8 y.

Chinese Experts Consensus and Practice Guideline on Discoid Lateral Meniscus

“…However, this qualitative description is more subjective and influenced by the examiner's experience. By an Intracavitary Conventional Array Probe or a Linear Array Probe, assessing quantitatively the morphology of lateral meniscus is reliable, noninvasive, convenient, and cost‐effective for diagnosing or screening DLM in children 119 . Yang et al 120 proposed the ultrasonic quantitative diagnostic criteria for DLM based on the angle formed by the upper and lower arc‐shaped surface of the meniscus at the free rim.…”

“…The real-time dynamic observation, the unique advantages of ultrasound, may enable it to become a reliable new method for diagnosing DLM and its classification and lesions. 41,[118][119][120]199 In recent years, there are many studies about the diagnosis of X-ray on DLM and its classification, but X-ray can only be used as an indicative diagnostic method because its diagnostic value is influenced by measuring error and the distance between the X-ray tube and knee joint. [17][18][19][123][124][125][126][127][128][129] The key points of DLM treatment are restoring the normal shape, retaining the appropriate width and thickness, and preserving the remnant meniscus's stability.…”

“…The accuracy of ultrasonography in diagnosing meniscus lesions is comparable to that of MRI, but the diagnosis of DLM and its classification and lesions is potential and still in the preliminary exploration stage. The real‐time dynamic observation, the unique advantages of ultrasound, may enable it to become a reliable new method for diagnosing DLM and its classification and lesions 41,118–120,199 . In recent years, there are many studies about the diagnosis of X‐ray on DLM and its classification, but X‐ray can only be used as an indicative diagnostic method because its diagnostic value is influenced by measuring error and the distance between the X‐ray tube and knee joint 17–19,123–129 …”

“…By an Intracavitary Conventional Array Probe or a Linear Array Probe, assessing quantitatively the morphology of lateral meniscus is reliable, noninvasive, convenient, and costeffective for diagnosing or screening DLM in children. 119 Yang et al 120 proposed the ultrasonic quantitative diagnostic criteria for DLM based on the angle formed by the upper and lower arc-shaped surface of the meniscus at the free rim. The cut-off value of the anterior horn angle, body angle, and posterior horn angle in diagnosing DLM were 28.45 , 27.85 , and 29.15 , respectively.…”

Feasibility and efficacy of ultrasound in the diagnosis of discoid lateral meniscus and its classification in children: protocol for a prospective, multicentre, diagnostic test study

“… 17 Coincidentally, the width of the DLM in children that can be observed through ultrasound is 19.85±3.63 mm. 26 Therefore, measuring the width and angle α of the lateral meniscus in children using ultrasound can distinguish NLM from DLM and IDLM from CDLM. Ultrasound examinations will be performed as previously described.…”