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Ipsilateral Medial and Lateral Discoid Meniscus with Medial Meniscus Tear
Kengo Shimozaki1, Junsuke Nakase1, Yoshinori Ohashi1
1Department of Orthopaedic Surgery, Kanazawa University, 13-1 Takara-Machi, Kanazawa-Shi, Ishikawa-Ken 920-8641, Japan.
Introduction:
Discoid meniscus is a well-documented knee pathology, and there are many cases of medial or lateral discoid meniscus reported in the literature. However, ipsilateral concurrent medial and lateral discoid meniscus is very rare, and only a few cases have been reported. Herein, we report a case of concurrent medial and lateral discoid meniscus.
Case Report:
A 27-year-old Japanese man complained of pain on medial joint space in his right knee that was diagnosed as a complete medial and lateral discoid meniscus. In magnetic resonance imaging, although the lateral discoid meniscus had no tear, the medial discoid meniscus had a horizontal tear. Arthroscopic examination of his right knee similarly revealed that the medial discoid meniscus had a horizontal tear. In addition, the discoid medial meniscus also had an anomalous insertion to the anterior cruciate ligament, and there was also mild fibrillation of the medial tibial cartilage surface. We performed arthroscopic partial meniscectomy for the torn medial discoid meniscus but not for the asymptomatic lateral discoid meniscus. The latest follow-up at 18 months indicated satisfactory results.
Conclusion:
We report a rare case of ipsilateral medial and lateral discoid meniscus with medial meniscus tear. The medial discoid meniscus with tear was treated with partial meniscectomy, whereas the lateral discoid meniscus without tear was only followed up.
Insights
Concurrent medial and lateral discoid meniscus is a rare knee condition. This case highlights successful arthroscopic partial meniscectomy for a torn medial discoid meniscus, with observation of the asymptomatic lateral discoid meniscus.
Area of Science:
- Orthopedic Surgery
- Knee Anatomy
- Diagnostic Imaging
Background:
- Discoid meniscus is a congenital anomaly of the knee meniscus.
- While isolated medial or lateral discoid menisci are documented, concurrent ipsilateral presentation is exceptionally rare.
- This report details an extremely uncommon case of simultaneous medial and lateral discoid menisci.
Observation:
- A 27-year-old male presented with right knee medial joint space pain.
- Magnetic resonance imaging (MRI) and arthroscopic examination revealed a complete medial and lateral discoid meniscus.
- The medial discoid meniscus exhibited a horizontal tear and anomalous anterior cruciate ligament insertion, while the lateral discoid meniscus was intact.
Findings:
- Arthroscopic partial meniscectomy was performed on the symptomatic, torn medial discoid meniscus.
- The asymptomatic lateral discoid meniscus was managed conservatively with observation.
- At 18-month follow-up, the patient reported satisfactory outcomes after treatment for the medial meniscus tear.
Implications:
- This case underscores the importance of thorough diagnostic evaluation for concurrent discoid menisci.
- It suggests a tailored treatment approach, addressing symptomatic tears while monitoring asymptomatic anomalies.
- Further research into the natural history and optimal management of combined medial and lateral discoid menisci is warranted.
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