- Board Directives and Guidelines (NEL) (preexisting condition)
- Permanent impairment {NEL} (degree of impairment) (back)
- Preexisting condition (disc, degeneration)
- Apportionment (non-economic loss) (preexisting conditions)
The worker suffered a low back injury in 2011, diagnosed as L4-5 disc herniation and sequestration, and right L5 radiculopathy. The Board's NEL clinical specialist rated the permanent impairment at 24% but reduced the award by half, to 12%, on the basis of pre-existing moderate multi-level degenerative changes and severe foraminal stenosis at L5-S1. On objection by the worker, the Appeals Resolution Officer found the pre-existing condition to be measurable at 7% and, accordingly, reduced to NEL award from 24% to 17%. The worker appealed, claiming that there should be no reduction of the NEL award.
Board Operational Policy Manual, Document No. 18-05-05, on the effect of a pre-existing impairment, has provisions for both measurable and non-measurable pre-existing impairments. If the pre-existing condition is measurable, the Board rates the pre-existing impairment and subtracts that rating from the total impairment rating. If the pre-existing impairment is not measurable, the Board reduces the rating according to the significance of the pre-existing impairment, and refers to the SIEF policy. If the pre-existing impairment is minor, there is not reduction, if it is moderate, there is a 25% reduction and if it is major, there is a 50% reduction.In this case, the employer had not been granted SIEF relief. However, the Vice-Chair stated that Document No. 18-05-05 does not require SIEF relief to have been granted in order to factor out pre-existing impairments.The ARO found that the worker had a measurable pre-existing impairment, and assigned a rating of 7% to that impairment based upon the rating for moderate to severe degenerative changes in Table 53IIC of the AMA Guides. However, the Vice-Chair noted that the rating based on Table 53IIC is not for the degenerative changes in and of themselves; rather, it is granted when injury and a minimum of six months of persistent pain and rigidity is associated with those changes. In this case, there was no evidence of six months of pain and rigidity associated with the underlying degenerative changes. Accordingly, the worker did not have a measurable pre-existing impairment.The Vice-Chair was satisfied that the worker had a pre-accident impairment. However, the NEL rating for the compensable injury contained little or no enhancement for the pre-existing impairment. Thus, the medical significance of the pre-existing impairment was, at best, described as minor in terms of its enhancement of the work-related impairment and its contribution to the total impairment. According to the Board policy, there is no reduction if the medical significance of the pre-existing impairment is minor.The worker was entitled to the full 24% NEL award without reduction. The appeal was allowed.