Table 1: PRiSM (Pediatric Research in Sports Medicine)

classification system for lateral discoid meniscus.17

Component

Description

Width

W0

Normal

W1

Incomplete, wider than normal, covering < 90% of the tibial plateau

W2

Almost complete/full, covering ≥ 90% of the tibial plateau

Height

H0

Normal, similar to a normal meniscus

H1

Abnormal, greater than a normal meniscus

Instability

S0

Normal stability

SA

Abnormal stability in the anterior half of the meniscus

SP

Abnormal stability in the posterior half of the meniscus

SAP

Abnormal stability in the anterior and posterior meniscus

Tear type

T0

No tear or tear in the central/flatten zone

THA

Horizontal in the anterior half

THP

Degenerative/complex/radial

THAP

Tear location

TDA

Radial, complex, or degenerative tear in the anterior half

TDP

Radial, complex, or degenerative tear in the posterior half

TDAP

Radial, complex, or degenerative tear in the anterior and posterior halves