Surgical Management of Medial Discoid Meniscus in Pediatric and Adolescent Patients

Abstract

Background: Medial discoid meniscus (MDM) is an exceedingly rare anatomic abnormality that presents similarly to other meniscal pathologies. Symptomatic MDM is typically managed arthroscopically with mixed short-term and long-term outcomes, although the existing knowledge about MDM is limited. The purpose of this study was to describe the presentation and surgical treatment of MDM in pediatric and adolescent patients. Methods: Medical records of 12 knees with MDM in 8 pediatric and adolescent patients treated between 1991 and 2016 were reviewed retrospectively for patient characteristics, clinical manifestations, radiographic findings, operative techniques, and surgical outcomes. Results: Of the 446 knees diagnosed arthroscopically with discoid menisci, lateral discoid meniscus was noted in 434 knees (97.3%) and MDM was present in 12 knees (2.7%). The MDM series included 8 patients of mean age 13.8 years (range: 7.8 to 19.8), of which 5 were males (63%), and 4 (50%) had bilateral involvement. Of the 11 knees with available clinical records, all cases presented symptomatically (pain, mechanical symptoms); 10 (91%) had concurrent physical exam findings. On intraoperative examination, discoid morphologies were described as complete in 4/8 knees (50%) or incomplete in 4/8 (50%), with associated instability in 6/12 (50%). Meniscal tears were reported in 9 cases (75%)-primarily, horizontal cleavage tears. Saucerization was performed in 11 knees (92%), with medial meniscal repair in 7 (58%), when indicated. Retear of the medial meniscus occurred in 4/11 knees (36%) at a mean of 25.8 months postoperation; 2 knees required revisions. One knee developed arthrofibrosis and underwent arthroscopic lysis of adhesions. Conclusions: MDM is a rare diagnosis, representing 3% of all discoid menisci, with a nonspecific clinical manifestation. Operative management of symptomatic MDM typically involves saucerization and meniscal repair, when indicated, for concurrent tears. Symptom resolution is common short-term, but long-term outcomes include recurrent meniscal tears. Subsequent observational studies are important to evaluate long-term outcomes, such as arthritic changes, with the advancement of arthroscopic techniques for meniscal preservation. Level of Evidence: Level IV-retrospective case series.

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

“…{{ Bilateral discoid medial menisci were previously reported in 1 of 4 patients, 18 1 patient, 36 3 of 4 patients, 38 2 of 2 patients, 44 and 4 of 8 patients. 17 Our rate of bilateral discoid medial menisci was substantially lower at 1 of 21 patients. We did have 1 patient with discoid medial and lateral menisci, as did Jeannopoulos, 24 and 1 of 13 patients also had a discoid lateral meniscus as well as a discoid 20 34/39 3/39 6/39 Sabbag (2018) 35 60 12/60 Kang (2019) 25 47/60 23/60 15/60 36/60 Hampton (2021) 21 27/32 2/32 19/32 Hesse (2021) 23 71/78 30/71 Lins (2021) 27 25/30 {{ medial meniscus in the same knee in the study by Chen et al 10 Specifically, Chen et al 10 reported on 13 operatively treated patients with discoid medial menisci over a 43-year period at 1 hospital.…”

“…A 2021 retrospective case series at 1 institution reported 8 patients with discoid medial menisci in 12 knees, with tears in 75% of knees, a majority of which were horizontal cleavage tears. 17 Furthermore, 2 patients (16.7%) required reoperation after saucerization and meniscal tear repair. This is consistent with the 17.4% of cases that required reoperation in our study.…”

Young Children with a Bucket-Handle Tear to the Discoid Lateral Meniscus Successfully Treated Using Arthroscopic Saucerization and Repair: Two Case Reports

“…Therefore, long leg casts were applied for the first month after surgery. Otherwise, the rehabilitation protocol was not different from the suggestions by the previous studies [ 17 , 18 ].…”

Arthroscopic Saucerization and Repair of a Torn Medial Discoid Meniscus

“…Other symptoms reported include locking of the knee, pain in flexion and extension, effusion, positive McMurray’s test, and reduced range of motion. 4 , 5 Repairing a torn posterior horn is important, given its role as a secondary stabilizer, as well as to protect the cartilage. 6 A medial discoid meniscus may have its anterior horn anomalously inserted on the anterior cruciate ligament ( Fig 9 ).…”

“…Four cases sustained retears and 1 developed arthrofibrosis, while all other patients were asymptomatic at final follow-up. 5 …”