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Thoracic Spondylosis N030

Last amended 
22 December 2020
Current RMA Instruments
Reasonable Hypothesis SOP64 of 2014
Balance of Probabilities SOP 65 of 2014
Changes from previous Instruments

SOP Bulletin 176

ICD Coding
  • ICD-9-CM Codes: 721.2,721.41,722.51,721.4,722.5,722.6
  • ICD-10-AM Codes: M47.14, M47.15, M47.24, M47.25, M47.84, M47.85, M47.94, M47.95, M51.3
Brief description

Thoracic spondylosis is a degenerative disease affecting the joints in the thoracic spine, i.e. the intervertebral discs and the facet joints (zygapophyseal joints).  It results from mechanical joint stress.  It results in upper to mid back pain and stiffness.  The thoracic spine includes all thoracic vertebra from T1 to T12 as well as the thoraco-lumbar junction (T12/L1).

Confirming the diagnosis

The diagnosis requires both clinical manifestations (symptoms and signs) and evidence of relevant bone/joint pathology (osteophytes, disc space narrowing, facet joint degeneration).  Imaging (X-ray, CT, MRI) evidence is required by the SOP definition and should be used to confirm the pathological changes, unless it can't be obtained (see comments below).  

The relevant medical specialist is an orthopaedic surgeon, neuro/spinal surgeon, or rheumatologist.

Additional diagnoses covered by these SOPs
  • Degenerative disc disease of the thoracic spine.
  • Disc desiccation of the thoracic spine.
  • Facet joint osteoarthritis of the thoracic spine.
  • Osteoarthritis of the throacic spine.
Conditions which may be covered by these SOPs
  • Thoracic disc prolapse or herniation – An isolated thoracic disc prolapse is covered by the intervertebral disc prolapse SOP. However, if the thoracic disc prolapse occurs in the presence of pre-existing thoracic spondylosis, it is likely that the new thoracic disc prolapse is an integral manifestation of the thoracic spondylosis rather than a separate disease.
  • Thoracic spinal stenosis – The stenosis may be a separate additional pathology or may be an integral manifestation of the thoracic spondylosis rather than a separate disease. Separate thoracic spinal stenosis may be due to congenital/developmental anomaly, disc prolapse, or other space occupying lesions such as neoplasia.
Conditions not covered by these SOPs 
  • Ankylosing spondylitis*                                  
  • Diffuse Idiopathic Skeletal Hyperostosis (DISH) #
  • Isolated bulging of a disc# – A disc bulge without any other concomitant signs of disc pathology such as disc desiccation, annular tears, endplate changes, osteophytes, is likely to be a physiological change and hence not a disease or injury.
  • Musculoligamentous strain or sprain of the thoracic spine* - Sprain and strain SOP   
  • Scheuermann’s disease#

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

# non-SOP condition

Clinical onset

Once the diagnosis has been confirmed it may be possible to back-date clinical onset based on the relevant associated symptoms.  Back pain is a non-specific symptom, with other possible causes. The nature and pattern of the symptoms (location, temporal connection, persistence etc.) needs to be consistent with a degenerative origin.  Difficulties in assessing onset may arise where a prior acute back injury, or surgery (e.g. for a disc prolapse) has occurred and symptoms have persisted subsequently.  The time to develop clinically apparent spondylosis post injury is variable and dependent on factors such as the nature and extent of the injury and age.  Most commonly, spondylosis onset following a joint injury occurs between ages 40 and 50.  Onset may be as soon as 5 years post injury, particularly if of older age at the time of injury, but is more likely to be 10 years or more (and up to several decades later), particularly if the injury occurred at a young age (<25). The clinical onset will not be at the time of an initiating trauma/injury.  The degeneration takes time to develop following a trauma.

Imaging evidence of joint degeneration does not establish a clinical onset, as clinical manifestations from the degeneration are required.  However, in the case of a prior injury or joint disorder, in the absence of a change in symptoms, and where a diagnosis of spondylosis has been made, date of first imaging showing degeneration may provide the only available marker for the time of clinical onset.

Clinical worsening

The natural history of thoracic spondylosis is for the degenerative changes to slowly progress and worsen.  The symptoms may fluctuate over time and may improve in some cases.  Conventional medical therapy and operative treatment may alleviate symptoms but will not slow or reverse the condition.

Further comments on diagnosis

In exceptional circumstances the diagnosis may be confirmed without imaging, in a person > 50 years, with typical clinical manifestations, and in whom imaging cannot reasonably be undertaken or obtained.