This coding is relevant for suspected meniscal tears and when symptoms are suggestive of osteoarthritis.


Estimated activity
  • 80,315 episodes during 2018/19
  • Age/sex std rate per 100,000 – 135.2
  • Reduction opportunity based on 25th percentile of activity across CCGs: not calculated
  • Variation (age/sex std rates):
    • N-fold – 107.4
    • 10th percentile – 4.2
    • 25th percentile – 12.6
    • 50th percentile – 51.7
    • 90th percentile – 447.0

Procedure codes

U133: MRI bone/joint:

With site codes –

Z84.6 Knee joint

O13.2 Knee NEC


Diagnosis codes

Note – these diagnosis codes have been provided, but not reflected in the coding logic and example SQL code below, as the sparseness of OP diagnosis data means that this is less helpful in an OP setting. It is included here for information.

 M170: Primary gonarthrosis, bilateral

M171 Other primary gonarthrosis, incl:

Primary gonarthrosis:

  • NOS
  • Unilateral

M179: Gonarthrosis, unspecified


M000, 1,2, 8 &9 infection

M050-9 rheumatoid

M060-9 inflammatory

M070-9 reactive

M020-9 arthropathies

M030-9 post infection

M100-9 gout

M120-9 other arthropathies

M130-9 other arthritis

M140-9 diabetic/ neuropathic

M150-9 polyarthrosis

M172, 3, 4 & 5: gonarthrosis resulting from trauma or other secondary

C402, 408, 409 neoplasm

D162 neoplasm

C765 neoplasm

(Note – cancer diagnoses are a global exclusion)


Any other criteria (e.g. patient age)

Adult (aged >=19 years)


Will the procedure be carried out in OP or as APC?



Coding logic

Procedure code in any position is:


With procedure in any position:

Z84.6 OR



Patient age >=19 years

SQL code

opa.Der _ Procedure _ All like '%U133%'
and (opa.Der _ Procedure _ All like '%Z846%'
or opa.Der _ Procedure _ All like '%O132%')
ISNULL(opa.Age _ at _ Start _ of _ Episode _ SUS,opa.Der _ Age _ at _ CDS _ Activity _ Date)between 19 and 120

Global cancer exclusion

((opa.der _ diagnosis _ all not like '%C[0-9][0-9]%'
and opa.der _ diagnosis _ all not like '%D0%'
and opa.der _ diagnosis _ all not like '%D3[789]%'
and opa.der _ diagnosis _ all not like '%D4[012345678]%')
OR opa.Der _ Diagnosis _ All IS NULL)