Ontario WSIAT – Pre-existing Degenerative Disc Disease – A Surprise, a Missed Opportunity


Pre-existing, Asymptomatic DDD Conditions

Not Grounds for Impairment-Rating Reductions

(As a Matter of Interpretation)


If the Ontario WSIB thought that through its November 2014 publication of its Operational Policy on “Determining the Degree of Permanent Impairment” – Policy No. 18-05-03 – it had authorized its adjudicators to reduce permanent impairment ratings for NEL purposes on the basis of pre-existing but asymptomatic degenerative disc diseases, it appears to have thought wrong.

In Decision No. 468/17, dated May 4, 2017, and in the three earlier decisions cited by 468/17, the Appeals Tribunal (WSIAT) has concluded that Policy 18-05-03 does not, on its own terms, in fact authorize the reduction of permanent impairment ratings on the basis of the existence of pre-existing, asymptomatic degenerative disc disease.


The Tribunal’s main points are these:

That for such reductions to be permitted, Policy 18-05-03 specifically requires that “the pre-existing condition, on its own, would result in an impairment rating [under the prescribed rating schedule (AMA Guides)]”.

That, properly interpreted, the latter reference is to the impairment rating under the Guides that would have resulted from the pre-existing conditions if those conditions had been rated before the workplace injury.

That under the Guides, the pre-injury rating for an asymptomatic, degenerative spinal condition is 0%, not the 6% or 7% identified by the Board’s adjudicators.

In these cases, the WSIB’s adjudicators had rated the pre-existing DDD conditions at a 6% or 7% impairment of the whole person in reliance on the Guides’ “Table 53, Impairments Due to Specific Disorders of the Spine, Disorder II – Intervertebral disc or other soft-tissue lesions – category C”.

Category C, defines intervertebral disc or other soft-tissue lesions as:

 Unoperated, with medically documented injury and a minimum of six months of medically documented pain and rigidity with or without muscle spasm, associated with moderate to severe degenerative changes on structural tests; includes unoperated herniated nucleus pulposus with or without radiculopathy …

However, prior to the work injury, the DDD conditions in these cases  had not been medically documented injuries, nor, as one of the Tribunal adjudicators noted, any injury at all. Neither had there been any documented pain or rigidity, much less for six months. The Tribunal concluded, accordingly, that, in its pre-accident state, these DDD conditions did not meet the criteria specified in Category C.

In the Tribunal’s view, the appropriate rating was to be found in Table 53, Disorder II (intervertebral disc or other soft-tissue lesions), Category ‘A’.  Table 53 defines the Category A criteria as “Unoperated, with no residual signs or symptoms”.  For Category ‘A’ lesions, the Guides assign a rating of “0%”.

Thus, either the conditions are conditions that would have resulted in no impairment rating at all, or are conditions that would have resulted in a 0% rating.

(Section 47(13) of the Act also provides, as the Tribunal noted, that where a worker’s degree of impairment is determined to be zero, the worker is deemed to have no impairment).

Accordingly, one way or another, the “significance” of the pre-existing DDD conditions would qualify as “minor” under the Board’s 18-05-03 Policy, and thus, on the terms of the Policy, they would not lead to any reduction.


The biggest surprise in the writer’s view is, of course, the fact that the Tribunal saw fit to apply Policy 18-05-03 at all; that it did not find it intrinsically unlawful as contrary to the thin skull doctrine. This missed opportunity is addressed at further length below.

While the writer found the Tribunal’s interpretation of the Policy in the 468/17 line of decisions also surprising – especially in the particular aspects listed below – they were only “surprising” in the sense that, on the basis of a superficial reading of the Policy, he found them unexpected.  He is not suggesting that these interpretations are not justified.  The interpretation reasoning is, indeed, in his opinion, convincing.

The first interpretation surprise, in the unexpected sense, is the interpretation of 18-05-03 as requiring the pre-existing condition to be rated as it would have been rated before the workplace injury.

The second surprise is how the Tribunal dealt with Policy 18-05-03’s direction to the Board’s adjudicators that:

The pre-existing condition does not need to have produced periods of impairment or disease requiring health care, or have caused a disruption in employment, in order to factor out its rating from the total impairment rating.

The 468/17 line of decisions holds that the latter direction is to be interpreted as simply authorizing the adjudicators to reduce the impairment rating on the basis of any pre-existing condition that would have attracted more than a 0% rating under the Guides, even though the condition had not required healthcare or caused a disruption.

As we have seen, the DDD conditions in question in the 468/17 line of cases did not qualify under that provision since in the Tribunal’s view they all would have attracted a 0% rating. Moreover, given the reasoning in those decisions, it would appear that the Tribunal is likely to find that any pre-existing degenerative spine condition that was not symptomatic prior to the injury would also attract a 0% rating and thus not qualify under that provision.

The third surprise is how the Tribunal dealt with Policy 18-05-03’s instructions regarding the circumstances where “the pre-existing condition cannot be rated according to the prescribed rating schedule”.  The policy specifies that, in those circumstances,

“… the medical significance of the pre-existing condition is [to be] determined based on the clinical evidence and the decision-maker reduces the total impairment rating of the area according to the determination”.

The Tribunal does not address the latter question, directly, but presumably its answer would be that, in the case of an asymptomatic degenerative disc disease, the condition can be rated; it can be rated under Table 53, Disorder II, Category A .  The rating is zero, but it is a rating.



As visitors to this site will know, this author is of the view that the WSIB’s Operational Policy 18-05-03 (and a number of associated Policies amended or published at the same time – November 2014) transparently abrogates the thin skull doctrine respecting pre-existing conditions and is, for that reason, inconsistent with or not authorized by the Act.  (See especially the second of the previous posts cited below.)

Since the Board’s post-November 2014 policy respecting pre-existing conditions destroys one of the central tenets of the system of compensation as the Act defines it – and as it has existed since time immemorial – the policy is in urgent need of having its lawfulness addressed by the Tribunal and referred to the Board for review under section 126(4).

The reason the 18-05-03 policy needs urgently to be subjected to a 126(4) review is that arguably it is only through a judicial review of a Board’s 126(8) direction to the Tribunal – the direction that follows the Board’s review – that the lawfulness of the Board’s post-November 2014 pre-existing conditions policy can be tested in the courts.

The referral/review/direction/judicial review process is the only straightforward means for getting the issue to the courts because any other avenue to a judicial review seems likely to be blocked by the courts’ prematurity doctrine respecting judicial reviews.

(Of course, the writer is assuming here that the Tribunal would find the policy “inconsistent with or not authorized by the Act” – to cite the 126(4) language – and that, on review, the Board would find it consistent and authorized and would issue a “direction” in accordance with that view.  These are not, one thinks, unwarranted assumptions.)

The 126(4)-(8) referral/review/direction/judicial review process needs to get underway as soon as possible so that Ontario’s system can be rid of this unlawful, destructive, pre-existing conditions  policy as soon as possible. It is in this context that the 468/17 line of decisions is disappointing; for these are decisions in which the Appeals Tribunal has foregone opportunities for a section 126(4) referral of the policy.

These opportunities presented themselves in the hearing of each of these four appeals. But instead of addressing the root unlawfulness of the 18-05-03 Policy, the Tribunal elected to consider whether that Policy, on its own terms, did in fact authorize discounting for pre-existing, asymptomatic degenerative disc disease and, as we have seen, found that it did not.

The writer’s concern with this line of decisions lies not only in the delay they cause in getting the lawfulness of the Board’s pre-existing conditions policy before the courts, but also in what is the implicit premise of the decisions – that is, that Policy 18-05-03 is not, as such, intrinsically incompatible with the Act per se. 

These decisions can be taken as implying that, if there were a  pre-existing, untreated and non-disruptive condition which could be rated at more than 0% under the Guides (or one which could not be rated under the Guides at all and so be open to a “determination” based on “clinical evidence”), then Operational Policy 18-05-03 would lawfully authorize a reduction based on those conditions.  There is a danger that this is an inference that in future case other Tribunal panels might well recognize as persuasive authority.

One obvious example of such a case would be a worker who has worked successfully for many years with an artificial leg and suffers some workplace injury that interferes with his use of that leg.

By dealing with the 18-05-03 Policy as presenting an interpretation issue rather than a section 126(4) ultra vires problem, the Tribunal is not only delaying the Policy’s appointment with the courts but might also be taken as conceding the Policy’s  core intra-vires status.

Moreover, with these decisions in place, injured workers are faced once again with the problem presented by the Board’s known practice of Tribunal denial – of turning a blind eye to the Tribunal’s interpretation of the Board’s operational policies.

Thus, the Board can be expected to continue to reduce impairment ratings based on pre-existing, asymptomatic degenerative disc disease, notwithstanding that it is now on notice that in due course such reductions will be reversed by the Tribunal – reversed, that is, for those relatively few  injured workers who have the rights-awareness and emotional and financial supports that it takes to mount and sustain such an appeal.


The system is in urgent need of having the legality of the Board’s November 2014 pre-existing conditions policy reviewed by the courts.

As noted above, because of the courts’ prematurity doctrine it does seem to be prima facie the case that the only way one can expect the legality issue to be reviewed by the courts is for the Tribunal to address the lawfulness of the impugned policy, find it inconsistent with or unauthorized by the Act, and send the policy to the Board for a section 126(4) review and direction.

Postponing that day of reckoning through a punctilious interpretation of the policy is not helping.


Of course, postponing the issue is helping the individual, injured worker appellant.  When the Tribunal does find that there is reason in an appeal to challenge the lawfulness of the pre-existing conditions policy, the appellant in that appeal will be the one to assume the burden of litigating the Board’s 126(8) direction through the judicial review process. He or she will also be the one to suffer the egregious delay in the restoration of their benefits that would be entailed in that process.

It is important here to note how much the delay in such proceedings will be exacerbated because of the requirement under the section 126(4) review process that the Tribunal postpone its final disposition of the appeal in which the lawfulness issue arises, until after the Board has reviewed the Tribunal’s finding on the lawfulness question and issued its direction to the tribunal.

And, given the contentious and systemic importance of this issue, the appellant’s litigation burden would be a heavy one indeed, as it seems very likely that the issue would not be finally resolved in the courts until at least the Court of Appeal had spoken – many many months hence.

So, okay – the Tribunal’s postponing of the 126(4) confrontation on the lawfulness of Policy No. 18-05-03 may be disappointing from a systemic perspective, but from other perspectives it is perhaps understandable.

Obviously, what in fact is needed is a better procedure – a more just and expeditious procedure – for getting the pre-existing conditions policy before the courts.  For instance, might the courts be persuaded in these circumstances to waive their prematurity doctrine and hear a direct, public-interest application for a declaration of illegality?



P.S. A more sensible and just system for dealing with policy lawfulness issues would be to replace section 126(4) with legislation that simply clarified the Board’s standing as an applicant for judicial review of any decision in which the Tribunal finds one of the Board’s policies to be unlawful.

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