FA33

ICD-11 MMS 2026-01

Internal derangement of knee

Description

Internal derangement of the knee (IDK) is a chronic disorder of the knee due to a torn, ruptured or deranged meniscus of the knee, or a partial or complete cruciate rupture, with or without injury to the capsular ligament, resulting in ongoing or intermittent signs and symptoms such as pain, instability, or abnormal mobility of that knee. If indicated that derangement is due to trauma, code to Injury, poisoning and certain other consequences of external causes, regardless of time past since injury.

Excludes

  • FA31 – deformity of knee
  • FA32 – Disorders of patella
  • FA32.0 – recurrent dislocation or subluxation patella
  • FA34.4 – Ankylosis of joint
  • http://id.who.int/icd/entity/2016483996 – Injuries to the knee or lower leg

Exclusions from above levels

  • http://id.who.int/icd/entity/1989556002 – Conditions associated with the spine
  • 01 – Certain infectious or parasitic diseases
  • 05 – Endocrine, nutritional or metabolic diseases
Show allHide
  • 18 – Complications of pregnancy, childbirth and the puerperium
  • 19 – Certain conditions originating in the perinatal period
  • 22 – Injury, poisoning or certain other consequences of external causes
  • DA0E.8 – Temporomandibular joint disorders

Child codes

  • FA33.0 – Cystic meniscus
  • FA33.1 – Discoid meniscus
  • FA33.2 – Derangement of meniscus due to old tear or injury
  • FA33.3 – Loose body in knee
  • FA33.4 – Chronic instability of knee
  • FA33.Y – Other specified internal derangement of knee
  • FA33.Z – Internal derangement of knee, unspecified

Sibling codes

  • FA30 – Acquired deformities of fingers or toes
  • FA31 – Other acquired deformities of limbs
  • FA32 – Disorders of patella
  • FA34 – Certain specified joint derangements
  • FA35 – Wear of articular bearing surface of joint prosthesis
  • FA36 – Effusion of joint
  • FA37 – Certain joint disorders, not elsewhere classified
  • FA38 – Arthropathy in diseases classified elsewhere

Foundation entity

Internal derangement of knee – http://id.who.int/icd/entity/1686749305

Allowed postcoordination axes

Part of: 15: Diseases of the musculoskeletal system or connective tissue