In the recent decision, Degennaro v. Oakville Trafalgar Memorial Hospital,  O.J. No. 2780 (S.C.J.), the Court considered the issue of reasonable foreseeability and chronic pain in the light of the Supreme Court of Canada's comments on this issue in Mustapha,  2 S.C.R. 114.
Gray J., considering whether chronic pain is a foreseeable injury in light of Mustapha, noted that: "There is obviously a subtle distinction between a person of less than ordinary fortitude who suffers damage that is not foreseeable, and a person of ordinary fortitude who suffers damage that is more serious than expected."
In Degennaro the plaintiff developed chronic pain after an injury that resulted in a fractured sacrum. The fracture healed but her pain got worse. There was no objective reason for the continuing and worsening pain. The eventual conclusion of her treating physicians was that the plaintiff had developed fibromyalgia. Although it was in dispute at the trial, the Court concluded that the chronic pain was caused by the same fall that had resulted in a fractured sacrum.
The Court then had to consider whether the chronic pain was foreseeable. This is what Gray J. wrote at paras 158-163.
158 In Mustapha, supra, the Supreme Court of Canada analyzed the issue. In that case, the Court held that it was not reasonably foreseeable that the plaintiff would suffer serious mental injury as a result of seeing flies in a bottle of water that he was about to install for a customer.
159 At para. 14 of her judgment, McLachlin C.J.C. stated that a plaintiff is to be considered objectively, not subjectively. Thus, a plaintiff is not to be considered in the context of his or her own personal makeup, which may give rise to the specific injury suffered, but rather objectively. That is, one must ask what a person of ordinary fortitude would suffer.
160 At para. 16 of her judgment, McLachlin C.J.C., in a passage that has some significance for this case, stated:
Once a plaintiff establishes the foreseeability that a mental injury would occur in a person of ordinary fortitude, by contrast, the defendant must take the plaintiff as it finds him for purposes of damages. As stated in White, at p. 1512, focusing on the person of ordinary fortitude for the purposes of determining foreseeability, "is not to be confused with the 'eggshell skull' situation, where as a result of a breach of duty the damage inflicted proves to be more serious than expected". Rather, it is a threshold test for establishing compensability of damage at law.
161 In my view, it is foreseeable that chronic pain may result from a physical injury. While the actual cause of chronic pain is not known, it is known that some people will develop chronic pain after physical trauma. Thus, chronic pain is foreseeable as falling within a range of consequences that may flow from a physical injury. This is a foreseeable consequence in a person of ordinary fortitude. Thus, in my view, the defendants must take the plaintiff as they find her. As noted by McLachlin C.J.C. at para. 16 of Mustapha, supra, this is simply a case where the damage inflicted has proven to be more serious than expected.
162 There is obviously a subtle distinction between a person of less than ordinary fortitude who suffers damage that is not foreseeable, and a person of ordinary fortitude who suffers damage that is more serious than expected. However, in view of the analysis in Mustapha, the distinction is real and must be respected. I have no doubt that Ms. Degennaro falls into the category of a person who is a person of ordinary fortitude who has suffered damage that is more serious than expected.
163 For the foregoing reasons, the chronic pain suffered by the plaintiff, Ms. Degennaro, was a foreseeable consequence of the incident that occurred in May, 1999, and the defendants must compensate her for it.