Excludes2

  1. M23 Internal derangement of knee

    Excludes1

    • ankylosis (M24.66)
    • deformity of knee (M21.-)
    • osteochondritis dissecans (M93.2)

    Excludes2

    • current injury - see injury of knee and lower leg (S80-S89)
    • recurrent dislocation or subluxation of joints (M24.4)
    • recurrent dislocation or subluxation of patella (M22.0-M22.1)
    1. M23.0 Cystic meniscus

      1. M23.00 Cystic meniscus, unspecified meniscus

        Inclusion term(s):

        • Cystic meniscus, unspecified lateral meniscus
        • Cystic meniscus, unspecified medial meniscus
        • M23.000 Cystic meniscus, unspecified lateral meniscus, right knee
        • M23.001 Cystic meniscus, unspecified lateral meniscus, left knee
        • M23.002 Cystic meniscus, unspecified lateral meniscus, unspecified knee
        • M23.003 Cystic meniscus, unspecified medial meniscus, right knee
        • M23.004 Cystic meniscus, unspecified medial meniscus, left knee
        • M23.005 Cystic meniscus, unspecified medial meniscus, unspecified knee
        • M23.006 Cystic meniscus, unspecified meniscus, right knee
        • M23.007 Cystic meniscus, unspecified meniscus, left knee
        • M23.009 Cystic meniscus, unspecified meniscus, unspecified knee
      2. M23.01 Cystic meniscus, anterior horn of medial meniscus

        • M23.011 Cystic meniscus, anterior horn of medial meniscus, right knee
        • M23.012 Cystic meniscus, anterior horn of medial meniscus, left knee
        • M23.019 Cystic meniscus, anterior horn of medial meniscus, unspecified knee
      3. M23.02 Cystic meniscus, posterior horn of medial meniscus

        • M23.021 Cystic meniscus, posterior horn of medial meniscus, right knee
        • M23.022 Cystic meniscus, posterior horn of medial meniscus, left knee
        • M23.029 Cystic meniscus, posterior horn of medial meniscus, unspecified knee
      4. M23.03 Cystic meniscus, other medial meniscus

        • M23.031 Cystic meniscus, other medial meniscus, right knee
        • M23.032 Cystic meniscus, other medial meniscus, left knee
        • M23.039 Cystic meniscus, other medial meniscus, unspecified knee
      5. M23.04 Cystic meniscus, anterior horn of lateral meniscus

        • M23.041 Cystic meniscus, anterior horn of lateral meniscus, right knee
        • M23.042 Cystic meniscus, anterior horn of lateral meniscus, left knee
        • M23.049 Cystic meniscus, anterior horn of lateral meniscus, unspecified knee
      6. M23.05 Cystic meniscus, posterior horn of lateral meniscus

        • M23.051 Cystic meniscus, posterior horn of lateral meniscus, right knee
        • M23.052 Cystic meniscus, posterior horn of lateral meniscus, left knee
        • M23.059 Cystic meniscus, posterior horn of lateral meniscus, unspecified knee
      7. M23.06 Cystic meniscus, other lateral meniscus

        • M23.061 Cystic meniscus, other lateral meniscus, right knee
        • M23.062 Cystic meniscus, other lateral meniscus, left knee
        • M23.069 Cystic meniscus, other lateral meniscus, unspecified knee
    2. M23.2 Derangement of meniscus due to old tear or injury

      Inclusion term(s):

      • Old bucket-handle tear
      1. M23.20 Derangement of unspecified meniscus due to old tear or injury

        Inclusion term(s):

        • Derangement of unspecified lateral meniscus due to old tear or injury
        • Derangement of unspecified medial meniscus due to old tear or injury
        • M23.200 Derangement of unspecified lateral meniscus due to old tear or injury, right knee
        • M23.201 Derangement of unspecified lateral meniscus due to old tear or injury, left knee
        • M23.202 Derangement of unspecified lateral meniscus due to old tear or injury, unspecified knee
        • M23.203 Derangement of unspecified medial meniscus due to old tear or injury, right knee
        • M23.204 Derangement of unspecified medial meniscus due to old tear or injury, left knee
        • M23.205 Derangement of unspecified medial meniscus due to old tear or injury, unspecified knee
        • M23.206 Derangement of unspecified meniscus due to old tear or injury, right knee
        • M23.207 Derangement of unspecified meniscus due to old tear or injury, left knee
        • M23.209 Derangement of unspecified meniscus due to old tear or injury, unspecified knee
      2. M23.21 Derangement of anterior horn of medial meniscus due to old tear or injury

        • M23.211 Derangement of anterior horn of medial meniscus due to old tear or injury, right knee
        • M23.212 Derangement of anterior horn of medial meniscus due to old tear or injury, left knee
        • M23.219 Derangement of anterior horn of medial meniscus due to old tear or injury, unspecified knee
      3. M23.22 Derangement of posterior horn of medial meniscus due to old tear or injury

        • M23.221 Derangement of posterior horn of medial meniscus due to old tear or injury, right knee
        • M23.222 Derangement of posterior horn of medial meniscus due to old tear or injury, left knee
        • M23.229 Derangement of posterior horn of medial meniscus due to old tear or injury, unspecified knee
      4. M23.23 Derangement of other medial meniscus due to old tear or injury

        • M23.231 Derangement of other medial meniscus due to old tear or injury, right knee
        • M23.232 Derangement of other medial meniscus due to old tear or injury, left knee
        • M23.239 Derangement of other medial meniscus due to old tear or injury, unspecified knee
      5. M23.24 Derangement of anterior horn of lateral meniscus due to old tear or injury

        • M23.241 Derangement of anterior horn of lateral meniscus due to old tear or injury, right knee
        • M23.242 Derangement of anterior horn of lateral meniscus due to old tear or injury, left knee
        • M23.249 Derangement of anterior horn of lateral meniscus due to old tear or injury, unspecified knee
      6. M23.25 Derangement of posterior horn of lateral meniscus due to old tear or injury

        • M23.251 Derangement of posterior horn of lateral meniscus due to old tear or injury, right knee
        • M23.252 Derangement of posterior horn of lateral meniscus due to old tear or injury, left knee
        • M23.259 Derangement of posterior horn of lateral meniscus due to old tear or injury, unspecified knee
      7. M23.26 Derangement of other lateral meniscus due to old tear or injury

        • M23.261 Derangement of other lateral meniscus due to old tear or injury, right knee
        • M23.262 Derangement of other lateral meniscus due to old tear or injury, left knee
        • M23.269 Derangement of other lateral meniscus due to old tear or injury, unspecified knee
    3. M23.3 Other meniscus derangements

      Inclusion term(s):

      • Degenerate meniscus
      • Detached meniscus
      • Retained meniscus
      1. M23.30 Other meniscus derangements, unspecified meniscus

        Inclusion term(s):

        • Other meniscus derangements, unspecified lateral meniscus
        • Other meniscus derangements, unspecified medial meniscus
        • M23.300 Other meniscus derangements, unspecified lateral meniscus, right knee
        • M23.301 Other meniscus derangements, unspecified lateral meniscus, left knee
        • M23.302 Other meniscus derangements, unspecified lateral meniscus, unspecified knee
        • M23.303 Other meniscus derangements, unspecified medial meniscus, right knee
        • M23.304 Other meniscus derangements, unspecified medial meniscus, left knee
        • M23.305 Other meniscus derangements, unspecified medial meniscus, unspecified knee
        • M23.306 Other meniscus derangements, unspecified meniscus, right knee
        • M23.307 Other meniscus derangements, unspecified meniscus, left knee
        • M23.309 Other meniscus derangements, unspecified meniscus, unspecified knee
      2. M23.31 Other meniscus derangements, anterior horn of medial meniscus

        • M23.311 Other meniscus derangements, anterior horn of medial meniscus, right knee
        • M23.312 Other meniscus derangements, anterior horn of medial meniscus, left knee
        • M23.319 Other meniscus derangements, anterior horn of medial meniscus, unspecified knee
      3. M23.32 Other meniscus derangements, posterior horn of medial meniscus

        • M23.321 Other meniscus derangements, posterior horn of medial meniscus, right knee
        • M23.322 Other meniscus derangements, posterior horn of medial meniscus, left knee
        • M23.329 Other meniscus derangements, posterior horn of medial meniscus, unspecified knee
      4. M23.33 Other meniscus derangements, other medial meniscus

        • M23.331 Other meniscus derangements, other medial meniscus, right knee
        • M23.332 Other meniscus derangements, other medial meniscus, left knee
        • M23.339 Other meniscus derangements, other medial meniscus, unspecified knee
      5. M23.34 Other meniscus derangements, anterior horn of lateral meniscus

        • M23.341 Other meniscus derangements, anterior horn of lateral meniscus, right knee
        • M23.342 Other meniscus derangements, anterior horn of lateral meniscus, left knee
        • M23.349 Other meniscus derangements, anterior horn of lateral meniscus, unspecified knee
      6. M23.35 Other meniscus derangements, posterior horn of lateral meniscus

        • M23.351 Other meniscus derangements, posterior horn of lateral meniscus, right knee
        • M23.352 Other meniscus derangements, posterior horn of lateral meniscus, left knee
        • M23.359 Other meniscus derangements, posterior horn of lateral meniscus, unspecified knee
      7. M23.36 Other meniscus derangements, other lateral meniscus

        • M23.361 Other meniscus derangements, other lateral meniscus, right knee
        • M23.362 Other meniscus derangements, other lateral meniscus, left knee
        • M23.369 Other meniscus derangements, other lateral meniscus, unspecified knee
    4. M23.4 Loose body in knee

      1. M23.40 Loose body in knee, unspecified knee

      2. M23.41 Loose body in knee, right knee

      3. M23.42 Loose body in knee, left knee

    5. M23.5 Chronic instability of knee

      1. M23.50 Chronic instability of knee, unspecified knee

      2. M23.51 Chronic instability of knee, right knee

      3. M23.52 Chronic instability of knee, left knee

    6. M23.6 Other spontaneous disruption of ligament(s) of knee

      1. M23.60 Other spontaneous disruption of unspecified ligament of knee

        • M23.601 Other spontaneous disruption of unspecified ligament of right knee
        • M23.602 Other spontaneous disruption of unspecified ligament of left knee
        • M23.609 Other spontaneous disruption of unspecified ligament of unspecified knee
      2. M23.61 Other spontaneous disruption of anterior cruciate ligament of knee

        • M23.611 Other spontaneous disruption of anterior cruciate ligament of right knee
        • M23.612 Other spontaneous disruption of anterior cruciate ligament of left knee
        • M23.619 Other spontaneous disruption of anterior cruciate ligament of unspecified knee
      3. M23.62 Other spontaneous disruption of posterior cruciate ligament of knee

        • M23.621 Other spontaneous disruption of posterior cruciate ligament of right knee
        • M23.622 Other spontaneous disruption of posterior cruciate ligament of left knee
        • M23.629 Other spontaneous disruption of posterior cruciate ligament of unspecified knee
      4. M23.63 Other spontaneous disruption of medial collateral ligament of knee

        • M23.631 Other spontaneous disruption of medial collateral ligament of right knee
        • M23.632 Other spontaneous disruption of medial collateral ligament of left knee
        • M23.639 Other spontaneous disruption of medial collateral ligament of unspecified knee
      5. M23.64 Other spontaneous disruption of lateral collateral ligament of knee

        • M23.641 Other spontaneous disruption of lateral collateral ligament of right knee
        • M23.642 Other spontaneous disruption of lateral collateral ligament of left knee
        • M23.649 Other spontaneous disruption of lateral collateral ligament of unspecified knee
      6. M23.67 Other spontaneous disruption of capsular ligament of knee

        • M23.671 Other spontaneous disruption of capsular ligament of right knee
        • M23.672 Other spontaneous disruption of capsular ligament of left knee
        • M23.679 Other spontaneous disruption of capsular ligament of unspecified knee
    7. M23.8 Other internal derangements of knee

      Inclusion term(s):

      • Laxity of ligament of knee
      • Snapping knee
      1. M23.8X Other internal derangements of knee

        • M23.8X1 Other internal derangements of right knee
        • M23.8X2 Other internal derangements of left knee
        • M23.8X9 Other internal derangements of unspecified knee
    8. M23.9 Unspecified internal derangement of knee

      1. M23.90 Unspecified internal derangement of unspecified knee

      2. M23.91 Unspecified internal derangement of right knee

      3. M23.92 Unspecified internal derangement of left knee

Abbreviations used here:

NEC Not elsewhere classifiable
This abbreviation in the Tabular List represents “other specified”. When a specific code is not available for a condition, the Tabular List includes an NEC entry under a code to identify the code as the “other specified” code.

NOS Not otherwise specified
This abbreviation is the equivalent of unspecified.