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Osteoarthritis N002

Document
Last amended 
19 September 2017
Current RMA Instruments
Consolidated Reasonable Hypothesis SOP
13 of 2010 as amended by 35 of 2011
Consolidated Balance of Probabilities SOP
14 of 2010 as amended by 36 of 2011
Changes from previous instruments

SOP Bulletin 150

ICD Coding
  • ICD-9-CM: 715
  • ICD-10-AM: M15, M16, M17, M18 or M19.
Brief description

Osteoarthritis is a degenerative joint disease involving the loss of articular (joint) cartilage and associated changes to the underlying bone and joint margins.  It results from mechanical joint stress.  It results in pain, stiffness and loss of function in the affected joint.

Confirming the diagnosis

To confirm the diagnosis there needs to be both:

  • evidence of clinical symptoms and signs (pain, impaired function and stiffness) in the affected joint;

AND

  • Imaging (X-ray, CT, MRI) or arthroscopic evidence of degenerative cartilage loss or osteophyte (bony spur) formation.

Radiological evidence alone is insufficient for diagnosis, clinical manifestations (symptoms and signs) must be present.

The relevant medical specialist is an orthopaedic surgeon or rheumatologist.

Additional diagnoses covered by these SOPs
  • degenerative joint disease (except spondylosis)
  • osteoarthrosis (except in the spine)
Additional conditions that may be covered
  • degenerative labral tear - A degenerative labral tear may be an associated feature of osteoarthritis of the hip joint or the gleno-humeral joint in the shoulder.  A degenerative labral tear of the hip may also be an associated feature of femoroacetabular impingement syndrome, or may be an incidental radiological finding.  If a degenerative labral tear is present in conjunction with osteoarthritis of the hip or shoulder, it should generally be considered to be part of the osteoarthritis.
  • degenerative meniscal tear - A degenerative meniscal tear may be an associated feature of osteoarthritis of the knee, or may be an incidental radiological finding.  If a degenerative meniscal tear is present in conjunction with osteoarthritis of the knee, it should generally be considered to be part of the osteoarthritis.
Conditions not covered by these SOPs   
  • acute articular cartilage tear*                
  • acute traumatic chondral defect* (acute articular cartilage tear SOP)
  • osteoarthritis of the spine* (cervical spondylosis, thoracic spondylosis, or lumbar spondylosis SOPs)
  • osteochondritis dissecans#                  
  • osteoporosis*                                              
  • rheumatoid arthritis*                                                            

* another SOP applies  - the SOP has the same name unless otherwise specified

# non-SOP condition

Clinical onset

Once the diagnosis has been confirmed (including by having imaging or arthroscopic evidence of cartilage loss/osteophytes in that joint), it may be possible to back-date clinical onset based on the relevant associated symptoms, particularly pain.  The nature and pattern of the symptoms (location, temporal connection, persistence etc.) needs to be consistent with a degenerative origin.  Clinical onset may be pointed to by symptoms that commenced (and then persisted) from days up to a some months before confirmation of diagnosis.  However, joint pain is a non-specific symptom, with other possible causes.  Time of clinical onset should generally not be based on earlier symptom episodes, particularly if intermittent.  The clinical onset will not be at the time of an initiating trauma/injury.  The degeneration takes time to develop following a trauma.  If multiple joints are involved, the time of clinical onset is likely to be different for each joint.

Clinical worsening

The natural history of osteoarthritis is to slowly progress and worsen.  Conventional medical therapy and operative treatment other than joint replacement may alleviate symptoms but will not slow or reverse the condition.

Further comments on diagnosis

Generally, each claimed joint that is affected by osteoarthritis will need to be individually diagnosed and determined, so that each of the causal factors can be considered in relation to that joint.

If, having examined the evidence, it is apparent that two or more joints can be accepted using the same causal factor then such joints can be collectively diagnosed (eg, both knees affected and obesity factor met - diagnose as osteoarthritis both knees).

The diagnosis for each joint or group of joints should describe the site/s involved.  The term generalised osteoarthritis should not be used.