Arthroscopic Management of Giant Meniscal Cysts Among Young Patients: An Average Three-Year MRI Follow-Up

Objective To describe an arthroscopic technique for giant meniscal cyst excision with preservation of the functional meniscus, report the short- and medium-term outcomes, and assess magnetic resonance imaging (MRI) for follow-up imaging evaluations. Methods A total of 54 consecutive patients with symptomatic meniscal cysts were admitted to the Second Xiangya Hospital of Central South University between 2014 and 2019. Nine patients with giant meniscus cysts (six females and three males) were included in this study. The age range of the patients was 6-34 years. All patients underwent a complete physical examination, X-ray, Doppler ultrasound, and MRI of the knee preoperatively. After an arthroscopic diagnosis of a meniscal rupture with a giant meniscal cyst, partial meniscectomy, ablation of the cyst, and suturing of the retainable meniscus were performed. Lysholm and International Knee Documentation Committee (IKDC) scores were used preoperatively and at the most recent follow-up. Clinical outcomes were classified into four categories: excellent, good, fair, and poor. During the last visit, all patients underwent MRI to assess the recurrence of the cyst and meniscal suture healing. Results Preoperative MRI and arthroscopic examination revealed giant meniscal cysts combined with meniscal tears and congenital discoid meniscus, and all giant meniscal cysts occurred in the lateral meniscus. The main types of meniscal tears were horizontal and complex tears. The cysts were unicystic in one case and multicystic in eight cases. The mean size of the cysts on the MRI was 5.86 cm x 2.24 cm x 2.48 cm. The mean follow-up periods were 37.5 (19-60) months. Clinical outcomes were excellent in six patients and good in three patients. The postoperative scores were significantly improved compared to the preoperative scores (Lysholm: 90.78 +/- 4.60 vs. 54.56 +/- 7.25; IKDC: 96.2 +/- 3.46 vs. 61.69 +/- 3.36; p <0.01). No recurrence of the cyst was indicated on the MRI, and there was good healing of the torn meniscus. Conclusions Arthroscopic cystectomy combined with the meniscus suture technique was effective to eradicate residual cyst cavities, and traffic orifices be highly recommended.