"The Vagaries of Analyzing and Predicting the Deterioration of the Human Spine"
The BC Court of Appeal released reasons for judgement yesterday addressing the difficulty of assessing damages for personal injuries to the spine when a pre-existing deteriorating condition is in play.
In yesterday’s case (Bouchard v. Brown Bros. Motor Lease Canada Ltd.) the Plaintiff was involved in a 2005 rear-end collision. He was faced in an awkward position when his vehicle was struck and he sustained injuries.
Although there was competing medical evidence, the Court ultimately found the collision was a cause of a L4-5 disc herniation which required bilateral discectomies and foraminotimies at the L4-L5 and L5-S1 levels of the spine. The Court found that while the collision was a cause of the injury, that there was “a very significant risk” that the Plaintiff’s back problems would have developed even absent the collision and the damages were reduced by 40% to take this risk into account. The BC Court of Appeal held that this reduction was too drastic and reduced the global damages by 20% instead of 40%. In doing so the Court provided the following reasons:
 The vagaries of analyzing and predicting the deterioration of the human spine as it ages are a source of difficulty not only for the medical profession but for anyone involved in resolving personal injury claims. This appeal reflects that difficulty: it involves a plaintiff who at the age of 20 was diagnosed with a narrowing of the L5-S1 disc, then experienced a period of apparent recovery, and then suffered an injury in a motor vehicle accident in 2005 that was found to have been a “significant factor contributing to the herniation of [his] disc at L4-L5, and the development of … symptoms of severe and disabling lower back pain”. No challenge is made to this finding of causation. Rather, the plaintiff challenges the trial judge’s conclusion that there was a “very significant risk” he would have “gone on to suffer serious low back problems” in the absence of the injury in 2005, and that therefore, all the damages that would otherwise have been awarded against the defendants should be reduced by 40%…
 I agree that it was open to the judge to reduce those damages which were awarded in respect of future loss, to reflect the possibility that “ultimately”, Mr. Bouchard would in any event have experienced serious lumbar problems. There was, however, no evidence to suggest that absent the 2005 accident, Mr. Bouchard would have experienced serious and symptomatic degeneration of the spine at the age of 31 (his age at the date of trial) or within a brief time thereafter. Indeed, all the expert evidence suggested such deterioration occurs gradually, subject to specific incidents such as the one that occurred in October 2007. Dr. Hepburn used the word “ultimately” and was not asked to elaborate. Had he been asked, I expect he would have said that one cannot predict with certainty at what age disc degeneration would (or might) have become symptomatic and disabling to Mr. Bouchard, or even that it would necessarily have done so by a particular age.
 Similarly, the trial judge did not describe any time line over which he found there was a 40% chance Mr. Bouchard’s spine would have degenerated to its present state. Obviously, the process could not be projected with exactitude, but the reduction of damages by 40% suggests a very steep upward line on a graph. That line is contrary to the notion of gradual deterioration. If there was a 40% chance Mr. Bouchard would have deteriorated to his present condition by, say, age 50, the chance between ages 31 and 50 would have been less than 40%. This must as a matter of logic be reflected in the percentage by which the damages are reduced…
 I am also of the view that the trial judge erred in applying the 40% reduction to all heads of damage, including those that refer only to past loss and expenses. Obviously, the damages given for past income loss and special damages would not be affected by the future contingency posited by the trial judge. As for non-pecuniary damages, since the trial judge did not consider the contingency in his initial assessment of the award of $160,000, I am of the view that this court’s comments at para. 25 of York v. Johnston (1997) 37 B.C.L.R. (3d) 235 are not applicable. There is authority for reducing damages under this head to reflect a pre-existing condition: see Zacharas v. Leys 2005 BCCA 560, at paras. 25-6. I would therefore also reduce the award for non-pecuniary damages by 20% rather than 40%.