Is formal decompression necessary for parameniscal cysts associated with meniscal tears?

BACKGROUND: Meniscal tears and associated parameniscal cysts have good outcomes after partial meniscectomy and cyst evacuation. Good outcomes have been noted after partial meniscectomy with recurrent cysts. This investigation asks if partial meniscectomy without meniscal cyst decompression is sufficient for positive patient outcome.

METHODS: Sixteen patients treated between 2005 and 2010 for a meniscal cyst and concomitant meniscal tear. Inclusion criteria were meniscal tear and parameniscal cyst per MRI, no prior surgery on the affected knee, and Outerbridge classification of I/II. Two patients were excluded. Fourteen patients completed the study until final follow-up. Lysholm knee scores were documented at 6 months post-operatively and at final follow-up. Re-evaluation or second surgery of the treated knee was documented.

RESULTS: Eight lateral cysts and six medial cysts were diagnosed. Eight cysts were associated with a horizontal cleavage tear, while six menisci had a complex tear with a horizontal cleavage component. The average cyst size was 1.3 cm (0.5 to 3.5) at the largest diameter. At 6 months, the average Lysholm knee score was 94.1. At mean 5 years, the average score was 89.1. Patients with medial cysts, cysts greater than 1.0 cm, horizontal cleavage tears, or without simultaneous chondroplasty scored higher in the short and medium-term than their respective counterparts.

CONCLUSIONS: Excellent short and medium-term outcomes can be achieved following partial meniscectomy without cyst decompression for patients with meniscal cysts and associated meniscal tears.

LEVEL OF EVIDENCE: Level IV.