Surgical management of the discoid meniscus

Discoid meniscus is the most frequent intraarticular paediatric knee congenital condition. Only symptomatic patients require surgical attention with arthroscopy. The incidence of discoid meniscus repair is increasing.

Typical presentation is an insidious popping or snapping when mobilizing the knee. The older individuals can experience pain and effusion. Restricted knee motion suggests a meniscal rim instability. MRI confirms the diagnosis, with shape and volume criteria, and helps planning surgery. The most common tear pattern of the discoid meniscus is a horizontal tear. Regarding meniscal rim instability, MRI strongly correlates with arthroscopy.

Treatment includes saucerization, which consists of a gentle central meniscectomy to restore normal shape and volume, and repair when needed. Repair is indicated in case of peripheral detachment of the meniscal rim and when central meniscectomy has revealed a meniscal tear within the remaining tissue. Meniscectomy is only appropriate in case a tear is irreparable. Short term clinical outcome is excellent although revision rate can reach 44 % at 20 years.

Surgical management of the discoid meniscus has transitioned from a resection-focused approach to one centred on preservation and functional repair. The results of rim preserving arthroscopic saucerization are favourable, yet with a substantial arthroscopic revision rate. Risk factors for failure and revision should be further investigated.

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