[Medial discoid meniscus in a pediatric patient. Case report and review of the literature]

Discoid meniscus is a congenital morphological variant of the meniscus, which tends to occur more frequently in its lateral form than in the medial form. This anomaly is characterized by central hypertrophy of the meniscus and a larger diameter than the normal meniscus, resulting in an abnormal shape and greater coverage of the tibial plateau. The clinical presentation of this condition varies depending on the stability of the meniscus. In pediatric patients, in particular, it is common to experience progressive and atraumatic symptoms, such as pain and limited mobility. Diagnosis is based on imaging studies, with magnetic resonance imaging being the preferred tool, where the "bowtie sign" is a classic finding. Surgery is recommended for symptomatic patients, with a focus on preserving the peripheral portion of the meniscus. Saucerization is the most commonly used technique, followed by stability assessment to determine if additional procedures are required. In this case, a 9-year-old patient with a medial discoid meniscus presented symptoms following trauma. Despite this atypical presentation, a successful outcome was achieved through arthroscopic surgery, underscoring the importance of accurate diagnosis and proper management of this condition in pediatric patients. Understanding the anatomical and pathophysiological characteristics of the discoid meniscus is essential for an effective therapeutic approach.

Relationship Between Age and Pathology With Treatment of Pediatric and Adolescent Discoid Lateral Meniscus: A Report From the SCORE Multicenter Database

BACKGROUND

Surgical treatment options of discoid lateral meniscus in pediatric patients consist of saucerization with or without meniscal repair, meniscocapular stabilization, and, less often, subtotal meniscectomy.

PURPOSE

To describe a large, prospectively collected multicenter cohort of discoid menisci undergoing surgical intervention, and further investigate corresponding treatment of discoid menisci.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A multicenter quality improvement registry (16 institutions, 26 surgeons), Sports Cohort Outcomes Registry, was queried. Patient characteristics, discoid type, presence and type of intrasubstance meniscal tear, peripheral rim instability, repair technique, and partial meniscectomy/debridement beyond saucerization were reviewed. Discoid meniscus characteristics were compared between age groups (<14 and >14 years old), based on receiver operating characteristic curve, and discoid morphology (complete and incomplete).

RESULTS

In total, 274 patients were identified (mean age, 12.4 years; range, 3-18 years), of whom 55.6% had complete discoid. Meniscal repairs were performed in 55.1% of patients. Overall, 48.5% of patients had rim instability and 36.8% had >1 location of peripheral rim instability. Of the patients, 21.5% underwent meniscal debridement beyond saucerization, with 8.4% undergoing a subtotal meniscectomy. Patients <14 years of age were more likely to have a complete discoid meniscus (P < .001), peripheral rim instability (P = .005), and longitudinal tears (P = .015) and require a meniscal repair (P < .001). Patients ≥14 years of age were more likely to have a radial/oblique tear (P = .015) and require additional debridement beyond the physiologic rim (P = .003). Overall, 70% of patients <14 years of age were found to have a complete discoid meniscus necessitating saucerization, and >50% in this young age group required peripheral stabilization/repair.

CONCLUSION

To preserve physiological "normal" meniscus, a repair may be indicated in >50% of patients <14 years of age but occurred in <50% of those >14 years. Additional resection beyond the physiological rim may be needed in 15% of younger patients and 30% of those aged >14 years.

Medial Discoid Meniscus: A Rare Case Report

The meniscus is a glossy white structure found in the knee between the femoral condyle and tibial plateau in the medial and lateral aspects of both knees. The main purposes of the meniscus are to enhance joint congruity and stability, transmit load, and absorb stress. A rare type of anomaly of the meniscus shape is called discoid meniscus, which presents as an atypical shape also known as disk cartilage. This report presents a 13-year-old male with a history of left knee pain after a fall. The pain was stabby in nature with a decrease in range of motion in the left knee and positive McMurray and Apley's tests on examination. The patient was treated by arthroscopic saucerization, and the procedure was successful. The patient had a good postoperative outcome after two months of follow-up.

Efficacy of short-term splint immobilization in the treatment of pediatric discoid lateral meniscus after saucerization management

There are no universal guidelines for rehabilitation after saucerization for children with discoid lateral meniscus. This study determined if short-term knee splint immobilization and delayed rehabilitation produces the same benefit as early rehabilitation after saucerization in children, in terms of knee function and pain intensity. A retrospective review was performed by categorizing patients into 2 groups depending on whether a splint immobilization was adopted postoperatively: for group A, rehabilitation began early without splint immobilization after surgery, and for group B, a knee splint was immobilized for 2 weeks. Numerical rating scale scores were collected in patients 1, 3, and 7 days, Lysholm scores were measured at 4 and 8 weeks postoperatively, and the gradual return to normal activities was documented. Forty-eight patients and 53 knees were included: group A had 30 patients with 31 knees, and group B had 18 patients with 22 knees. There was no improvement in numerical rating scale scores on the 1st (P=.519), 3rd (P=.421), and 7th (P=.295) postoperative days in group B. The Lysholm scores of group A (62.94 ± 8.68) was higher than that of group B (46.68 ± 9.82) measured 4 weeks following surgery, but there was no difference at 8 weeks (P=.237), and both groups had similar time to return to normal activities (P=.363). For discoid lateral meniscus patients who underwent isolated saucerization, short-term splint immobilization did not significantly help relieve postoperative pain. There was a comparable time-course for return to normal activities in both study groups.

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.

The discoid lateral meniscus in children: a narrative review of pathology, diagnosis and treatment

Background and Objective

The discoid lateral meniscus (DLM) is a congenital abnormality of the meniscal shape, characterized by a typical central hypertrophy and a diameter larger than a regular meniscus, potentially leading to knee pain and symptoms, especially in children. The present study provides an update and a general review of this uncommon meniscal pathology. The incidence of discoid meniscus is about 0.4-17% for the lateral and 0.1-0.3% for the medial, although, being often asymptomatic, the true prevalence is unknown. We aim to enhance awareness on this subject to medical care provider.

Methods

A literature search was performed on PubMed, including articles written in English until October 2021.

Key Content and Findings

The articles regarding etiology, diagnosis and management of DLM in children or in patients younger than 18 years were reviewed using the narrative approach.

Conclusions

Recent literature has shown that DLM is one of the most frequent congenital anomalies of the knee encountered during childhood. While asymptomatic children with incidental finding can be managed nonoperatively, symptomatic painful DLM should be addressed surgically, restoring typical anatomy using saucerization, tear repair, and stable fixation of the meniscus. The risk of osteoarthritis progression seems to be higher in children with operated DLM, imposing prolonged follow-up and cartilage preserving strategies for these patients.

Risk Factors Associated With Knee Joint Degeneration After Arthroscopic Reshaping for Juvenile Discoid Lateral Meniscus

BACKGROUND

Although arthroscopic meniscal reshaping for discoid lateral meniscus (DLM) has better outcomes than total or subtotal meniscectomy, degenerative changes on radiographs are still seen in some patients with meniscal reshaping.

PURPOSE

To assess the risk factors associated with knee joint degeneration after reshaping surgery for juvenile DLM.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Forty patients (45 knees) with a mean age of 12.0 years who underwent arthroscopic meniscal reshaping for DLM were enrolled at a mean of 39.6 months after surgery. For all patients, meniscal saucerization was performed first. Then, if the residual meniscus was unstable, stabilization was provided with suture fixation. At final follow-up, we obtained radiographs to assess degenerative changes to the knee joint using the classification by Tapper and Hoover. Residual meniscal width and meniscal extrusion (defined as a relative percentage of extrusion [RPE]) were measured with magnetic resonance imaging (MRI). Then, the correlation between radiographic evidence of degenerative changes (Tapper and Hoover grade), residual meniscal width, and RPE were assessed with Pearson and Spearman correlation analyses. Logistic regression analysis was used to examine whether preoperative characteristics correlated with degeneration and residual meniscal width.

RESULTS

The mean residual meniscal width was 4.6 mm (range, 3.8-6.0 mm), and the mean ± SD RPE was 25.5% ± 21.8% at the final follow-up. There were 28 knees with Tapper and Hoover grade 0, 10 knees with grade 1, and 7 knees with grade 2. The residual meniscal width and RPE were significantly correlated with Tapper and Hoover grade (ρ = -0.489, P = .0007; ρ = 0.414, P = .005, respectively). The residual meniscal width was also significantly correlated with RPE ( r = -0.416, P = .004). The receiver operating characteristic curve showed that a 5.0-mm residual meniscal width was the cutoff value leading to evidence of degeneration. Multiple logistic regression analysis showed that an anterocentral shift on preoperative MRI was a risk factor for degeneration (odds ratio, 27.2; 95% CI, 1.1-360.5; P = .012) and residual meniscal width less than 5.0 mm (odds ratio, 20.9; 95% CI, 1.5-281; P = .022).

CONCLUSION

Smaller meniscal width and greater severity of meniscal extrusion correlated with knee joint degeneration. An anterocentral shift on preoperative MRI was a risk factor for degenerative changes and smaller residual meniscal width.

Effect of triggering and entrapment on tendon gliding properties following digital flexor tendon laceration: in vitro study on turkey tendon

The optimal management of partial flexor tendon laceration is controversial and remains a clinical challenge. Abnormal tendon gliding (triggering and entrapment) was assessed at the A2 pulley in 40 turkey tendons in three groups: intact, partially divided (palmar or lateral), and trimmed. Testing was of gliding resistance and friction coefficient at 30° and 70° of flexion, loaded with 2 and 4 N. We observed for triggering and entrapment. The changes in gliding properties were compared and analysed using Wilcoxon matched pair testing. A significant difference was found in the change in gliding properties of intact to lacerated and lacerated to trimmed tendons and between tendons that glided normally compared with those exhibiting triggering or entrapment. This suggests that palmar and lateral lacerations which, through clinical examination and visualization, are found to glide normally should be treated with early mobilization. However, partial lacerations that exhibit triggering or entrapment should be trimmed.