DATE: 2024-11-25 ONTARIO SUPERIOR COURT OF JUSTICE

BETWEEN:

WILLIAM DALLNER

Plaintiff

• and -

DR. MICHAEL GLADWELL

Defendant

Counsel: John Tamming, for the plaintiff Christine Wadsworth and Sean Petrou, for the defendant

Heard: April 2, 3, 4, 5, and 16, 2024

REASONS FOR JUDGMENT

Justice R. Chown

INTRODUCTION

[1] Mr. Dallner sues Dr. Gladwell for medical malpractice. There is no issue that Mr. Dallner suffered an injury to his brachial plexus during shoulder replacement surgery performed by Dr. Gladwell on January 4, 2018. The sole issue is whether the plaintiff has proven surgical negligence on the part of Dr. Gladwell. There are no allegations of improper pre- or post-operative care. The plaintiff withdrew his allegation of lack of informed consent.

[2] I have concluded that it is more likely than not that Mr. Dallner’s injury resulted from surgical negligence on the part of Dr. Gladwell. I therefore find for the plaintiff.

LEGAL FRAMEWORK

Elements of Negligence

[3] The plaintiff must prove that the defendant was negligent, and that the defendant’s negligence caused the plaintiff’s loss. To prove negligence, the plaintiff must show that:

1. the defendant owed a duty of care to the plaintiff;
2. the defendant’s behaviour breached the standard of care;
3. the plaintiff sustained damage; and
4. the damage was caused, in fact and in law, by the defendant’s breach.

See, e.g., Mustapha v. Culligan of Canada Ltd., 2008 SCC 27, at para. 3.

[4] In this case, there can be no doubt that Dr. Gladwell owed Mr. Dallner a duty of care. There is also no doubt that Mr. Dallner sustained an injury in the surgery, and that the injury resulted in damages. The focus of the dispute is whether Dr. Gladwell breached the standard of care and whether that breach caused Mr. Dallner’s injury.

Proving a breach of the standard of care in a medical malpractice case

[5] To establish a breach of a duty of care in a medical malpractice case, the plaintiff must first establish, with adequate particularity, what the duty of care was. This must be done in reference to the prevailing standards of practice in the applicable field of medicine: Ter Neuzen v. Korn, [1995] 3 S.C.R. 674, at para. 34. In this case, there is little controversy about the applicable standard of care.

[6] The plaintiff must next prove that the defendant did something in breach of that standard of care.

Onus

[7] It is settled law that the onus of proving negligence always remains with the plaintiff. There is, however, some nuance to this.

[8] In the House of Lords decision in McGhee v. National Coal Board, [1973] 1 W.L.R. 1, at p. 6, Lord Wilberforce said, “it is a sound principle that where a person has, by breach of a duty of care, created a risk, and injury occurs within the area of that risk, the loss should be borne by him unless he shows that it had some other cause.” After McGhee, many Canadian courts accepted that there was a shifting onus in negligence cases. However, in Snell v. Farrell, [1990] 2 S.C.R. 311, the Supreme Court of Canada did not endorse this approach. Writing for the court, Sopinka J. said (Snell, at p. 330):

It is not strictly accurate to speak of the burden shifting to the defendant when what is meant is that evidence adduced by the plaintiff may result in an inference being drawn adverse to the defendant. Whether an inference is or is not drawn is a matter of weighing evidence. The defendant runs the risk of an adverse inference in the absence of evidence to the contrary. This is sometimes referred to as imposing on the defendant a provisional or tactical burden. In my opinion, this is not a true burden of proof, and use of an additional label to describe what is an ordinary step in the fact-finding process is unwarranted.

The legal or ultimate burden remains with the plaintiff, but in the absence of evidence to the contrary adduced by the defendant, an inference of causation may be drawn although positive or scientific proof of causation has not been adduced. [Citation omitted. Emphasis added.]

[9] Sopinka J. also said (Snell, at p. 328):

In many malpractice cases, the facts lie particularly within the knowledge of the defendant. In these circumstances, very little affirmative evidence on the part of the plaintiff will justify the drawing of an inference of causation in the absence of evidence to the contrary.

[10] Emery J. put it this way, in Rathan v. Scheufler, 2023 ONSC 3232, at para. 155:

In medical malpractice cases, a plaintiff is permitted to ask the court to draw a causal inference from all the facts as he or she is often under anesthesia or unable to provide direct evidence for some other reason. These facts include the final injury as evidence as to what took place when receiving medical care.

[11] At the same time, courts must not act with “the perfect vision afforded by hindsight”: Lapointe v. Hôpital Le Gardeur, [1992] 1 S.C.R. 351, at p. 363, [1992] S.C.J. No. 11, at para. 28. It is wrong to reason backwards to conclude, based only on a bad surgical outcome, that the surgeon must have been negligent. As this was a major focus of defence counsel throughout the trial, I will have more to say about this later in these reasons.

WITNESSES

[12] There were, in total, four witnesses in this trial. The plaintiff testified and he called one expert: Dr. Robin Richards. The defendant testified and he called one expert: Dr. Tracy Wilson. Both experts are highly qualified orthopaedic surgeons.

[13] Dr. Richards has testified in court many times as an expert witness. Dr. Wilson has never testified in court as an expert witness before. Their evidence had much in common. Where they differed, as I will explain, I preferred some parts of each of their testimonies.

KEY DOCUMENT

[14] The key document in this case is the operative note prepared by Dr. Gladwell immediately after the surgery, including the addendum he prepared shortly after talking to Mr. Dallner when Mr. Dallner woke up. The operative note describes the surgery and indicates that there were no complications. The addendum states, in part:

Bill has dense postoperative palsies of the median and ulnar nerves and paresthesias in the radial distribution with intact motor function. Most likely, this is due to intraoperative stretch. I am surprised by this as exposure of his shoulder was quite easy. In terms of retractors, a Gelpi retractor was used to retract conjoint tendon and deltoid. Hawkins-Bell retractor was not used. I do not think the Gelpi would have had any direct impact on the nerves. With glenoid exposure, this did not require any strenuous retraction, and again the exposure was actually quite easy. At the end of the case, Bill’s head and neck remained in a neutral position, with no sense that there would have been a traction injury higher up in plexus or around the cervical spine. Overall, I presume this is from retraction of the humerus during glenoid exposure, but again I am surprised by this.

I discussed with Bill the nerve palsies. Most likely, these are neurapraxias that will recover with time, but this is not guaranteed.

[15] It is not uncommon for shoulder arthroplasty patients to experience temporary paresthesia after the surgery. However, the extent of Mr. Dallner’s dysfunction was exceptional. Unfortunately, Mr. Dallner did not experience much recovery. I need not describe in detail his ongoing symptoms and limitations because the parties have agreed on damages.

FACTS

[16] Mr. Dallner wanted shoulder replacement surgery because his right shoulder was “worn out,” to use his phrase. Dr. Gladwell diagnosed glenohumeral arthritis. There is no dispute that Mr. Dallner needed the surgery (a total arthroplasty), and that he was a good candidate for the surgery.

[17] Total shoulder arthroplasty involves replacing both the ball (humeral head) and socket (glenoid) with implants. Dr. Gladwell had performed this surgery many times during his residency and during his two and a half years as a fully trained surgeon at the hospital in Owen Sound. He estimated he had performed the surgery on his own (i.e., after being in his own practice) 40 or 50 times.

[18] A necessary part of a total arthroplasty is dislocation of the shoulder. The arm must be moved into a non-natural position so that the surgeon can gain access to the glenoid and to the top of the humerus, where implants will be installed. “Release” of the humerus through spreading and cutting of tissue is required. Force is required to dislocate and position the shoulder for parts of the surgery. This is unavoidable. As I will explain, the patient’s arm must be repositioned several times during the surgery.

[19] As indicated, the injury Mr. Dallner sustained in the surgery was a brachial plexus injury. The brachial plexus is a network of nerves between the neck and upper arm passing under the clavicle into the armpit and supplying the arm with strength and sensation. During their testimony, Dr. Gladwell and both retained experts focused on only two ways the brachial plexus could have been injured:

1. by direct contact from retractors used during the surgery; or
2. by being stretched during the surgery.

In theory, it could also have been a combination of the two. As I will explain below, I have concluded that Mr. Dallner’s injury was most likely a stretch injury.

[20] The general surgical method used here is not criticized. In his testimony, Dr. Gladwell explained the surgery, but it was not necessary to explain every aspect of the surgery to address the issues in this case. The focus was on the steps that involved the use of retractors that might contact or compress the brachial plexus, and the steps that might stretch the brachial plexus. These steps are:

1. blunt dissection to expose the joint;
2. exposure of the humeral head;
3. exposure of the glenoid; and
4. second exposure of the humeral head.

[21] I will refer to these as “phases” one through four of the surgery. This is simply a convenient shorthand. The surgeons did not use the term “phases.” There is much more involved in the surgery, but both sides focussed on these aspects of the surgery as the relevant times when the injury may have occurred.

Blunt Dissection

[22] Dr. Gladwell explained that the surgery he performed on Mr. Dallner followed his usual routine. The patient is anaesthetized while reclined in a specialized chair (depicted in exhibit 14). 1 The patient’s arm is positioned about 30 degrees away from the body 2 and in a little bit of flexion 3 at the shoulder, with the elbow bent. The patient’s arm is positioned and held in place using a specialized arm positioner (depicted in exhibit 15). To gain access to the shoulder joint, the surgeon must separate the deltoid from the pectoralis major muscle. Dr. Gladwell used a Gelpi retractor (depicted in exhibit 16). A Gelpi retractor has bluntly pointed ends or tines. Dr. Gladwell applies one tine of the retractor to the conjoint tendon 4 and the other to the deltoid. He does not hook the retractor under the conjoint tendon, but rather he applies it into the fibers of the conjoint tendon. 5 Squeezing the retractor spreads the muscles apart. 6 The Gelpi retractor will be taken out once the humeral head is exposed. 7

Exposure of the Humeral Head

[23] To expose the humeral head, the arm is brought closer to the body (abducted) and lowered, putting the shoulder into extension. The arm is also externally rotated. The humeral head is exposed by bringing it up and out of the wound. Doing this involves releasing the humeral from soft tissue and using specialized retractors. The arm is in a non-natural, surgically created position at this point. Doing this does create some stretch of the brachial plexus. 8 Exposure of the humeral head allows for the ball of the humerus to be cut off during phase two and, during phase four, an implant installed. The arm may be placed in this position “a few times” 9 during the surgery. In this case, Dr. Gladwell’s post-operative note indicates that the arm was placed in this position only twice (for phases 2 and 4).

Exposure of the Glenoid

[24] The glenoid must also be exposed so that the socket of the shoulder joint can be replaced with an implant to match the implant installed on the humerus. Retractors, release of soft tissue, and repositioning of the arm is also required to access the glenoid. The surgeon needs perpendicular access to the glenoid for the tools used to prepare the glenoid to receive the implant. Achieving adequate exposure of the glenoid is the most physical part of the surgery because it is not natural for the proximal humerus to move behind the glenoid to get the required exposure Retraction of the humerus into this position involves some stretching of the surrounding tissues, including the brachial plexus. 10 Dr. Gladwell testified that “there's a lot of small adjustments from one patient to the next in order to find that arm position that works best for them where we can minimize the soft tissue releases, minimize force on the retractors, but all at the same time, get the view that you need to put the component in.” 11 He also said, “you end up needing to balance how much soft tissue you release on one hand versus how hard to push or pull on retractors on the other hand to find that sweet spot.” 12

MECHANISMS OF INJURY

[25] As indicated, the only mechanisms of injury raised by the parties are: (1) compression by a retractor; and (2) stretch. To expand briefly on this, Dr. Wilson said that surgical injuries to nerves could be direct or indirect. Two examples of direct injury would be injury by laceration, or injury by compression.

[26] In this case, laceration can be ruled out because Mr. Dallner has dysfunction that corresponds to injury to all three cords in the brachial plexus, i.e., the medial, posterior, and lateral cords. The damage is primarily to the medial cord but does involve all three cords. 13 To inadvertently injure all three of these with a laceration would be virtually impossible without also lacerating the axillary artery. 14 The patient would bleed profusely. In addition, the surgery does not involve the use of sharp instruments in this area.

[27] A compression injury could be caused by retractors. Dr. Richards considered that compression of the brachial plexus by the Gelpi retractor was one possibility of what occurred in this case. Dr. Wilson felt that this was unlikely because of the distance between the conjoint tendon and the brachial plexus.

[28] Indirect injury could occur through inadvertent traction of the nerve through extreme positioning of the arm or lengthening of the limb. The nerves running through the brachial plexus do have some elasticity to them. They stretch during everyday activities and have some mobility. It is possible, however, to injure them by overstretching them or leaving them in a position of stretch for too long.

[29] I will return to the cause of the injury below. For current purposes, the important point is that, given the limited possible mechanisms of injury, the discussion about the applicable standard of care can be limited. It is only necessary to consider the standard of care required to prevent these two concerns.

THE STANDARD OF CARE

The brachial plexus must be protected.

[30] Dr. Richards and Dr. Wilson agree that it is critical during the performance of a total shoulder arthroplasty for the surgeon to protect the brachial plexus, using only gentle retraction and avoiding extreme arm positioning, especially for prolonged periods of time. The surgeon must ensure that the retractors are safely placed and are not held with too much tension. It is the surgeon's responsibility to avoid this and to monitor the assistant's placement of retractors and tension on the retractors, as well as ensuring that the brachial plexus is not under any undue traction during arm positioning for the varied parts of the procedure, in particular, the exposure of the glenoid and proximal humerus.

[31] The brachial plexus is not within the surgeon’s field of vision at any time during the surgery. 15 As such, the surgeon must use reasonable judgment regarding how much force to place on the arm during repositioning and retraction. 16

The position of the arm and head must be monitored.

[32] Dr. Gladwell agreed that monitoring the position of the arm is part of the standard of care required of a surgeon. The standard of practice requires that the surgeon must ensure that the arm is supported and not left hanging. 17 The selection of equipment used during the surgery, including the arm positioner and the Gelpi retractor, was within the standard of care.

[33] The position of the head and neck must also be maintained in a neutral position as twisting or turning of the neck can increase the tension on the brachial plexus. 18

The shoulder should be returned to a neutral, relaxed position when possible.

[34] Dr. Wilson stated that because stretch injuries are a known issue, the standard of practice is to bring the arm back into a relaxed position with the arm at the side while the surgeon is doing other things, such as preparing cement, getting the implants, irrigating, or other smaller steps during the procedure. 19

[35] Dr. Gladwell also said that the arm “can’t be left in a position of stretch for long periods of time.” He said that “every opportunity that presents itself in surgery, you put the arm back to a more neutral position to relax those tissues.”

[36] During his cross-examination, Dr. Richards was referred to studies where intraoperative nerve monitoring showed a huge incidence of nerve problems during surgery. The point of the cross-examination was that surgeons do not have access to nerve monitoring during surgery, so do not know when the nerve is under strain. There is no real-time feedback to the surgeon for impending nerve injuries. 20 However, another point from one of the studies was that arm positioning was the major factor driving nerve signal changes. Removal of retractors without repositioning the arm did not result in a return to the baseline nerve signal. 21

[37] Overall, the evidence highlighted the importance of not leaving the arm in a position of stretch for longer than necessary to get the job done. 22

Intraoperative nerve monitoring is not required as part of the standard of care.

[38] In theory, intraoperative nerve monitoring could identify a problem was occurring. It involves the use of specialized equipment and additional personnel. It is used to perform certain academic studies but is not part of the normal standard of care in shoulder replacement.

THE CAUSE OF MR. DALLNER’S INJURY

[39] Dr. Gladwell admits that Mr. Dallner’s injury happened during the surgery 23 but denies it resulted from any negligence on his part. In his written submissions, he states that he took all necessary steps to try to protect the brachial plexus, but despite those precautions, nerve injuries can and do happen during this type of surgery. He says that no one knows how the injury occurred. At worst, he may have erred about the amount of force or traction that was applied, but this kind of error in judgment does not amount to negligence.

The Gelpi retractor did not cause the injury.

[40] I agree with Dr. Gladwell and Dr. Wilson that the Gelpi retractor likely did not cause the injury to Mr. Dallner’s brachial plexus. I accept the evidence that the brachial plexus is too deep and remote from the conjoint tendon to have been realistically impacted by the Gelpi retractor. Even if Dr. Gladwell hooked the Gelpi retractor under the conjoint tendon, the tine would not likely reach the brachial plexus. I accept that Dr. Gladwell likely followed his normal practice and did not hook it under the conjoint tendon, but rather, he hooked into the fibers of the conjoint tendon. Further, in cross-examination, Dr. Wilson made the point that the injury occurred to three nerves in the brachial plexus, and she thought it would be virtually impossible for that to occur with a Gelpi. 24 She uses the Gelpi herself. She is in a strong position to know whether the Gelpi could realistically impact the brachial plexus.

[41] Mr. Tamming observed that Dr. Gladwell’s addendum to his operative note indicated, “I do not think the Gelpi would have had any direct impact on the nerves.” Mr. Tamming tried to argue that Dr. Gladwell’s use of the phrase “I do not think,” suggests that the Gelpi was quite possibly the cause. Mr. Tamming tried to equate this to the statement, “I do not think I left a sponge in the patient.”

[42] I do not accept that the two statements are near equivalents. I agree that in his addendum note, Dr. Gladwell did not rule out the possibility the Gelpi caused the problem, but I accept as correct his belief that it did not have any direct impact on the nerves. I also do not see the note and Dr. Gladwell’s trial evidence as being inconsistent.

The injury was a stretch injury.

[43] Dr. Wilson clearly stated that a “tractional injury,” or stretching injury, is the most likely cause of Mr. Dallner’s injury. 25 She noted that the literature shows that this is the most common type of injury and stated that this is probably because the surgeon cannot know it is happening during the surgery. She said that there is no way for the surgeon to know what is happening to the brachial plexus because the patient is asleep, and the brachial plexus is not in the field of view. The surgeon will know that when they position the arm in extraordinary positions, the brachial plexus may be at risk, but there is no way of knowing with certainty. She said that patients with “tighter shoulders, different anatomy, previous injuries to the brachial plexus, you may put them in what you consider with your reasonable judgment, a position that is not terribly extreme, but adequate to access the different parts of the joint replacement that you need to access, and not have any idea that the brachial plexus is being stretched.” There is no feedback to the surgeon during the surgery as to the status or health of the nerves of the brachial plexus. 26

[44] Dr. Wilson also said that traction or stretch injuries occur frequently, but not to the extent here. They occur to an extent that the patient will feel numbness after the surgery, but most of these are transient and recover fully. 27

[45] Dr. Wilson went further and said that the medial cord is at greater risk, and Mr. Dallner’s injury likely happened, during the glenoid exposure phase (phase 3) of the surgery. The anatomy is such that the medial cord is most likely to be elongated when the arm is positioned for the glenoid exposure.

[46] As noted above, Dr. Gladwell stated in his addendum note that Mr. Dallner’s post-operative palsies were most likely “due to intraoperative stretch.” He went on to state, “I presume this is from retraction of the humerus during glenoid exposure, but again I am surprised by this.”

[47] I accept Dr. Wilson’s and Dr. Gladwell’s explanations as to the most likely mechanism of injury. Specifically, I find that Mr. Dallner’s injury did occur because of intraoperative stretch.

THE RARITY OF MR. DALLNER’S INJURY

[48] Dr. Richards testified that, in his 39 years of practice, he had never seen the complication that Mr. Dallner has experienced. More specifically, he has never seen a permanent injury to the medial cord of the brachial plexus from an anatomic shoulder replacement where the patient has not had previous surgery. 28 He further stated he had never heard of this injury before, under these circumstances. Dr. Richards has engaged in numerous academic studies and has done considerable academic writing, has followed the literature in his field, has spoken to many other surgeons, and has presented at and attended many conferences. Other surgeons will often send him case studies or consult with him about surgeries with bad outcomes. The fact that he has never heard of this outcome shows it must indeed be rare.

[49] In cross-examination, Dr. Wilson also testified that, in her 29 years of experience, she had not seen or heard of an injury to this degree from this surgery. 29 She agreed that it is amongst the more rare and severe injuries. 30

[50] I have already noted that it is not uncommon for shoulder arthroplasty patients to experience temporary paresthesia after the surgery. Dr. Richards acknowledged this. He said it is quite common and it usually recovers over a few weeks or months, and it is usually the axillary nerve. 31

[51] Dr. Wilson emphasized that nerve injuries during shoulder surgery are common. She described the medical literature on the incidence of nerve injuries during shoulder replacements. She reported that most nerve injuries occur due to inadvertent traction of the brachial plexus during retraction, especially at the extremes of movement. She said that most of the literature indicates the risk of nerve injuries is 1 to 4%, with some studies suggesting a risk of up to 22%. These figures include cases where any nerve deficit is found, including those that are mild and temporary and that completely recover. The studies often involve the use of intraoperative nerve monitoring or post operative nerve conduction studies. The sensitivity of the monitoring and nerve conduction studies is such that dysfunction can be “subclinical,” that is, detected by the instrument but not something that can be detected through examination or that is symptomatic. Dr. Richards made the point that intraoperative nerve monitoring seemed to be able to show minute changes in nerve function and “the harder you look for a nerve problem the more often you’ll find it,” but in general, long lasting nerve problems from this surgery are rare and, as stated, Mr. Dallner’s outcome is unprecedented in Dr. Richard’s experience.

[52] Ultimately, Dr. Wilson expressed the rarity of Mr. Dallner’s injury as follows:

But what we do know is in all the studies, the incidence of any kind of severe, permanent injury is very low. And there are different quoted rates, if you were to look at a study of 285 patients and one of them, where one of them went on to have a nerve grafting or whatever, you could develop an incidents in that study. But there is no literature that I know of, that states exactly how rare this is. It is very rare. I believe the fact that Dr. Richards and myself, Dr. Richards with all of his other experience and exposure hasn't seen it and I've never experienced it in my practice, it is of course rare, because if you look at numbers of cases that have been done, it's a rare injury.

ANALYSIS

[53] As a first step in the legal analysis, I will briefly outline the most recent Supreme Court of Canada decision on surgical negligence, Armstrong v. Ward, 2021 SCC 1, reversing 2019 ONCA 963. It is central to some of the issues. In Armstrong, the plaintiff’s ureter was damaged during surgery to remove Ms. Armstrong’s colon. The trial judge determined that the surgeon had come within two millimetres of the ureter with a cauterizing device, and this was a breach of the standard of care. At the Ontario Court of Appeal, the majority decision, written by Paciocco J.A., found that the trial judge erred by imposing an improper standard of care. He “used a goal or result in defining the standard of care, without finding that the goal or desired result could only have been missed by negligent acts or omissions”: Armstrong ONCA, at para. 47. Paciocco J.A. also said the trial judge did not properly define the standard of care and he conflated the standard of care and causation analysis. Van Rensburg J.A. dissented. She did not agree that the trial judge had failed to consider the possibility that the injury occurred without negligence: Armstrong ONCA, paras. 125 to 136. She did not agree that the trial judge had conflated the standard of care and causation: Armstrong ONCA, paras. 137 to 145. Specifically, she did not agree that the trial judge had reasoned backwards: para. 144.

[54] The differences between Paciocco J.A. and van Rensburg J.A. included differences in how they responded to the trial judge’s reasoning. However, a key difference in their expression of the law is found in paras. 56 and 57 and para. 136. Paciocco J.A. said that: “A trial judge who is prepared to proceed on the basis that only negligence could cause the relevant injury is obliged to consider and rule out non-negligent causes. Only if this is done, can the trial judge properly use success as the standard of care” (Armstrong ONCA, at para. 56). He then said:

[57] Nor can liability properly be grounded in the low risk of injury identified by the trial judge. It is a logical error to infer that since an adverse result is improbable, a defendant was negligent in causing that adverse result. Negligence needs to be proved in each specific case, unless it is established that the kind of injury in question can only occur through negligence. [Emphasis added.]

[55] Van Rensburg J.A. agreed that “it is a logical error to infer that since an adverse result is improbable a defendant was negligent in causing that adverse result,” but she did not agree with the part of the above paragraph that I have emphasized: Armstrong ONCA, at para. 136. Put differently, she did not agree that the plaintiff who seeks to rely on the nature of the injury as proof of causation must rule out all non-negligent causes.

[56] The Supreme Court of Canada’s decision is one line: “The appeal is allowed for the reasons of Justice van Rensburg, with costs throughout”: 2021 SCC 1.

[57] I will return to Armstrong in the discussion below.

This is primarily a standard of care case.

[58] Dr. Gladwell submits that this is “primarily a standard of care” case. That is, the major issue is whether the plaintiff has established that Dr. Gladwell breached the standard of care. I agree. I am satisfied that the cause was a stretch injury. The real question is whether the stretch injury resulted from a breach of the standard of care. Specifically, whether it resulted from the application of excessive force or by leaving the arm in a position of stretch for too long, contrary to the standard of care.

In this case, it is not necessary to determine if a breach of the standard of care occurred before determining causation.

[59] Dr. Gladwell next submits that the court “must first determine whether Dr. Gladwell breached the standard of care and only then turn to causation.” I do not agree with this submission. Before discussing the jurisprudence on this point, I want to first point out that Dr. Gladwell himself identified the most likely cause of Mr. Dallner’s injury within hours of the surgery. His addendum note said, “Most likely, this is due to intraoperative stretch,” and, “Overall, I presume this is from retraction of the humerus during glenoid exposure, but again I am surprised by this.” The most likely cause is readily determinable. In this case, it would be artificial to first determine whether there was a breach of the standard of care and only then turn to causation.

[60] The jurisprudence does indicate that it is typically best to determine whether there has been a breach of the standard of care before determining causation: Bafaro v. Dowd, 2010 ONCA 188, at para. 35. One reason for this is that proceeding in this order “ensures that the trial judge does not wrongly reason backwards from the fact of the injury to determine that the standard of care has been breached”: Armstrong ONCA, at para. 138. But in Armstrong, both Paciocco J.A. and van Rensburg J.A. agreed that where (as here) the nature of the injury is relevant to “what happened,” it is not an error to consider the injury in resolving whether the standard of care has been breached: Armstrong ONCA, at paras. 63 and 138 to 144. See also: Meringolo (Committee of) v. Oshawa General Hospital, [1991] O.J. No. 91 (C.A.), at para. 56, leave to appeal refused, [1991] S.C.C.A. No. 115; Grass (Litigation guardian of) v. Women’s College Hospital, [2001] O.J. No. 1766 (C.A.), at para. 12, leave to appeal refused, [2001] S.C.C.A. No. 372; and Kennedy v. Jackiewicz, [2003] O.J. No. 1854 (S.C.J.), at para. 6, affirmed [2004] O.J. No. 4816 (C.A.).

No inference of error may be drawn merely from a bad outcome.

[61] I agree with Dr. Gladwell’s next submission, that the inquiry must still not be result-oriented. As noted above, van Rensburg J.A. and Paciocco J.A. agreed that “it is a logical error to infer that since an adverse result is improbable, a defendant was negligent in causing that adverse result”: Armstrong ONCA, at paras. 57 and 136. If the odds of an adverse event are one in one hundred, it is to be expected that the event will occur once in one hundred times. In the long run, even rare events are likely to occur sometimes. If an event can occur, one must expect that it will sometimes occur. I fully agree that courts cannot lose sight of this principle, and the related concept that correlation does not prove causation.

The plaintiff is not required to rule out all non-negligent causes.

[62] At the same time, as I have reviewed above (see para. [55]) van Rensburg J.A. held, and the Supreme Court agreed, that a plaintiff is not required rule out all non-negligent causes. The wisdom in this is revealed if we consider a case where the outcome suggests that surgical negligence is a strong possibility, but a non-negligent cause is possible, although highly unlikely. The right approach must surely be to assess the likelihoods of each possibility. Otherwise, the plaintiff would be put to a burden of proof that goes beyond a balance of probabilities.

[63] This discussion brings to mind to some of the themes in Snell, at pp. 328 to 330, where Sopinka J. said:

• the traditional approach to causation was “too rigid”;
• causation is “essentially a practical question of fact”;
• causation “need not be determined by scientific precision”;
• “very little affirmative evidence on the part of the plaintiff will justify the drawing of an inference of causation in the absence of evidence to the contrary”; and
• whether an inference is or is not drawn is a matter of weighing evidence.

[64] Thus, proof of causation must be rooted in an assessment of the likelihoods, while remembering that:

• It is to be expected that rare events will sometimes occur. The mere fact that something rare has occurred proves very little.
• There are always people who will be more susceptible to injury than others, and the surgeon may be powerless to prevent the injury that the susceptible plaintiff sustained; and
• Hindsight is 20/20.

What happened in this case can be inferred from the outcome.

[65] In this case, the outcome of surgery can be used to make inferences about what happened in the surgery. I will point out again that Dr. Gladwell made inferences about what happened based on the outcome of the surgery. I need not repeat what Dr. Gladwell said about causation in his addendum note. Dr. Wilson also made inferences from the outcome of the surgery. She could tell the nerves had not been severed. She could tell the medial nerve was the most severely affected because the muscles and sensation it controls were most affected. She even inferred when in the surgery the injury most likely occurred: during the glenoid exposure. She inferred this in part based on the literature and in part because the way the arm is positioned for that part of the procedure is more likely to stretch the medial cord more severely than the lateral and posterior cord, and that corresponded to Mr. Dallner’s symptoms. As can be seen, a good deal can be inferred or deduced from the outcome of the surgery.

[66] Dr. Richards goes a step further than Dr. Wilson or Dr. Gladwell in what he is prepared to infer. He infers that the severe nature of the injury implies that a breach of the standard of care occurred. His inference is based on the nature of the surgery, the surgical steps that took place, his experience and knowledge of the surgery and the practice of orthopaedic surgery, and the nature of the injury. He said, “Permanent, irrevocable injury to the medial cord of the brachial plexus, from a patient having an anatomic scheduled shoulder replacement for primary glenohumeral osteoarthritis, who never had any surgeries before or injuries before, I haven't seen it, it doesn't happen. It shouldn't happen.” 32 This evidence has a parallel to the evidence in Armstrong, where one of the experts testified that the rate of injury to the ureter in cases like this “should be zero”: Armstrong ONCA, at para. 101.

Factors in the standard of care assessment.

[67] I turn now to whether Mr. Dallner has proven that there was a breach of the standard of care by Dr. Gladwell. I have identified four categories of considerations to be weighed.

1. The nature of the injury and the nature of the surgery.

[68] The severity of Mr. Dallner’s stretch injury has not been previously observed by two surgeons with combined experience of 68 years. Both surgeons have performed this surgery many times. Both stay well informed in their field of expertise. Neither of them had ever heard of an injury of this severity from this surgery.

[69] While the defence pointed to studies showing variable incidence rates for nerve injuries from this surgery, the studies referred to a broad spectrum of injuries (“all comers” – to use Dr. Richards’ phrase), including subclinical injuries in some cases. No one specifically pointed out a study that referred to injuries like Mr. Dallner’s. The highest point made for the defence was made by Dr. Wilson in her cross-examination, when she said several of the studies included descriptions of patients that required further surgery for tendon transfers or nerve grafts, and she said, “I would assume, without knowing those cases specifically, that those were very severe injuries, such as Mr. Dallner's.” 33

[70] Although Dr. Gladwell was surprised by Mr. Dallner’s injury, the likely cause (stretch during glenoid exposure) immediately came to his mind. It was the simplest explanation for what occurred. Since the day of the surgery, it has remained the most likely explanation. 34 Dr. Gladwell also said that the time he was stretching the tissues the most was during the glenoid exposure. 35

[71] I infer from the evidence that the greater the degree or duration of stretch, the greater the likelihood of injury and the more severe the injury is likely to be.

[72] In combination, the foregoing evidence is relatively strong circumstantial evidence that a high degree of force was applied, or the arm was left in a position of stretch for a long time. It is not a leap to say that, in the absence of another more probable explanation, the unusual degree of injury likely resulted from an unusual degree or duration of stretch.

[73] The surgeon is in full control of the placement of the arm and the duration that the arm is placed in various positions. It is part of the standard of care to avoid unduly stretching the arm. As a result, it can be fairly said that there is strong circumstantial evidence of causation and relatively strong circumstantial evidence of a breach of the standard of care.

2. The contemporaneous evidence as to the duration of non-natural positioning during glenoid exposure is limited.

[74] During his testimony, Dr. Gladwell stated that he does not “watch the clock during the surgery,” but he “remained mindful that the arm can't be left in a position of stretch for long periods of time.” He said that “every opportunity that presents itself in surgery, you put the arm back to a more neutral position to relax those tissues.” He then explained that the arm is put in a neutral position when it is moved for the different phases of the surgery.

[75] The duration of the various phases of the surgery is not charted in the operative note, but I do not suggest Dr. Gladwell is to be criticized for this. I would not draw an inference against Dr. Gladwell based on the fact this is not charted in the initial operative note. The surgeon cannot be expected to chart everything. As Gans J. said in Boutcher v. Cha, 2020 ONSC 7694, at para. 24, “The absence of specific details in an operative note regarding steps taken during surgery should not impact a trial judge’s findings, particularly where the surgery is commonplace in the defendant doctor’s practice. In that situation, the ‘invariable practice’ of the professional is to be given significant weight” [footnote omitted].

[76] In his addendum note, Dr. Gladwell still did not address the length of time that the arm was left in a position of stretch. He said he was surprised by the injury “as the exposure of his shoulder was quite easy.” He rejected the Gelpi retractor as the cause of the problem. However, he did not specifically describe bringing the arm into a relaxed position or say that it was not left in a position of stretch for very long. It would be unfair to place too much weight on the absence of such a comment in the addendum note, but the absence of any comment on this point is not entirely insignificant. Dr. Gladwell acknowledged in cross-examination that, at that moment, he was trying his best to understand what might have gone wrong, and as he went through it in his mind, he tried to put down everything relevant and important. 36 He was thinking about what went wrong, and he did not address this possibility.

[77] I see this point (i.e., the limited evidence of the duration of the non-natural positioning) as a point of only moderate significance. Again, it seems unfair to put too much emphasis on what the notes do not contain or on Dr. Gladwell’s inability to provide such specifics in his trial evidence. With that said, it certainly was not within Mr. Dallner’s power to provide any evidence on how long his arm was in a position of stretch.

3. The alternate explanations are weak and speculative.

[78] It is necessary to also assess the likelihood of potential non-negligent causes of Mr. Dallner’s injury. As I have said, it is not necessary that these are “ruled out.”

[79] Dr. Gladwell has advanced two possible ways that the injury could have happened without negligence. The first is that there was something about Mr. Dallner’s anatomy that made him exceptionally vulnerable to this injury, and there was no way for Dr. Gladwell to know or expect this. Dr. Wilson said that “in some patients, patients with tighter shoulders, different anatomy, previous injuries to the brachial plexus, you may put them in what you consider with your reasonable judgment, a position that is not terribly extreme, but adequate to access the different parts of the joint replacement that you need to access, and not have any idea that the brachial plexus is being stretched.” 37 Apart from further discussion about Mr. Dallner’s injuries, which I will discuss momentarily, the evidence on this point was not developed further than this. I have no basis to believe Mr. Dallner had tight shoulders or unusual anatomy. In fact, Dr. Gladwell admitted that there was nothing unusual about Mr. Dallner’s anatomy, other than the arthritis in his shoulder (which was the reason for the surgery). 38 Dr. Gladwell admitted that Mr. Dallner was a prime candidate for the surgery, and not everyone is. 39 Thus, the suggestion that there was something about Mr. Dallner’s anatomy that made him vulnerable to the injury he sustained is contrary to the evidence.

[80] The second alternate explanation is that Mr. Dallner was unusually susceptible to this injury because of his pre-existing injuries. Mr. Dallner dislocated his shoulder playing hockey in his mid-twenties. He had some physiotherapy for that. Mr. Dallner was an avid recreational water-skier and barefooter. He did injure his shoulder doing this from time to time. In his late thirties, he got a cortisone shot. He told Dr. Wilson that he had had many forceful falls while barefoot waterskiing and that he continued doing this until age 69, and that these injuries occasionally required treatment. He also told Dr. Richards that he had been very active with barefoot water-skiing for 34 years.

[81] Dr. Wilson testified that these injuries were pertinent because “each one of these very severe barefoot water-skiing injuries, additionally one on top of the other, can stretch the brachial plexus, when the arm is put in very extreme positions as people hit the water like cement; and that this could potentially be a mitigating factor … predisposing him to a nerve injury.” She said that scarring to a nerve can occur when it is stretched in such an injury. She described this as “intraneural scarring” that makes the nerve “less stretchable and more at-risk.” She acknowledged that she is not a neurologist but stated that this is well known. She said Mr. Dallner’s prior shoulder injuries predisposed him to a nerve injury. She also said that a history of shoulder injuries does not change the way the surgeon performs this surgery – “You should always be doing all the steps to protect a brachial plexus, whether it's normal or predisposed.” 40

[82] I was unimpressed with the theory that Mr. Dallner’s remote injuries explain the bad outcome. First, Dr. Wilson seemed to overstate the significance of the injuries. Dr. Wilson twice emphasized that falling at high speed when waterskiing is like hitting “cement” or a cement wall. She called them “very severe” injuries. I accept that Mr. Dallner had repeated shoulder injuries from waterskiing, and that he received treatment for some of these injuries, but it was not my impression that they were severe. Second, Dr. Gladwell’s pre-surgical examination did not reveal any neurological deficits or concern. Third, if these injuries could and did predispose Mr. Dallner to a nerve injury during surgery, I would have expected that this potential vulnerability would have been charted prior to surgery. No one pointed me to evidence of that. I would have expected it to be a factor in the exercise of judgment the surgeon must make. I can accept that the surgeon would “always be doing all the steps,” 41 but I do not accept that the surgeon would not take more care (less force, more resting for the arm) if the patient was predisposed to a nerve injury.

[83] I must also point out that Dr. Wilson’s opinion that the intraneural scarring predisposed Mr. Dallner to injury was based, at least in part, on backwards reasoning. Her opinion relied on the fact that when she had “ruled out,” to the best of her ability, a direct injury from the Gelpi retractor, the potential scarring was a suitable explanation for Mr. Dallner’s bad outcome. 42 Dr. Wilson could only “rule out” a negligent cause for the injury by uncritically accepting that Dr. Gladwell did not apply excessive force or leave Mr. Dallner’s arm in a position of stretch for an excessive length of time.

[84] I found the theory that Mr. Dallner’s anatomy or pre-existing injuries made him uniquely vulnerable to the surgical injury to be weak, speculative, and inadequately supported.

4. Dr. Gladwell believes he followed his normal surgical routine.

[85] A factor that supports Dr. Gladwell’s position is his evidence that he performed this surgery in accordance with his usual routine and this surgery was not particularly difficult. As already mentioned, the invariable practice of a professional can be given significant weight: Boutcher v. Cha, 2020 ONSC 7694, at para. 24; Belknap v. Meakes, at para. 39 to 40; Bafaro v. Dowd, at para. 29, affirmed 2010 ONCA 188.

[86] I accept that Dr. Gladwell cannot identify anything that may have been done incorrectly during Mr. Dallner’s surgery. However, I am not persuaded by his evidence that he followed the standard of care. An error can occur without the surgeon adverting to the error. Dr. Gladwell’s evidence that he followed his normal routine does not tip the scale in his favour. It is more likely than not that Mr. Dallner’s injury arose from excessive stretching due to excessive force being applied to the arm, or the duration of stretch being excessive.

Misjudgment or Negligence?

[87] Dr. Gladwell argues in his written submissions that, “At worst, this was an error in judgment in terms of how much stretch Mr. Dallner could bear. An error in judgment is not negligence.”

[88] I have considered whether Mr. Dallner’s injury results from acceptable professional misjudgment rather than negligence on the part of Dr. Gladwell. I accept that the surgeon must exercise judgment when assessing such things as: how much force to apply to reposition the patient’s arm, how precisely to move and position the arm, and how long to leave the arm in any non-natural position during the surgery. Each decision requires an exercise of judgment.

[89] To emphasize this point, I refer to something Dr. Gladwell said in his examination-in-chief:

During the surgery itself, there are times … where there's more stretch or strain on the brachial plexus … and I make sure that I'm judicious in terms of how much force I use during retraction, and during positioning, that I'm minimizing that stretch on the structures, really the soft tissues in their entirety, but including the brachial plexus and also careful to have the arm in any position of stretch for as little time as possible to get the job done.

[90] I accept that this is Dr. Gladwell’s normal practice. I also accept that he believes he did not do anything outside of his normal practice. However, this evidence does not overcome the inference of negligence from the other factors discussed above. One way to think about this is to ask whether Dr. Gladwell adverted to the risks, and used his judgment to apply the force he did, or to wait as long as he did to reposition the arm, balancing the competing concerns. Or did he fail to recognize that he was applying excessive force or taking too long with the arm positioned the way it was? I conclude that the latter is more likely after assessing all the circumstances, including the extreme rarity of the injury and the other factors I have discussed.

LEGAL CAUSATION

[91] I said above that the plaintiff in a negligence action must prove that the damage was caused, in fact and in law, by the defendant’s breach. Factual causation is shown where it is established that “but for” the breach, the injury would not have occurred. The foregoing discussion has dealt with causation in fact.

[92] Legal causation deals with whether the harm was reasonably foreseeable, or whether it was too remote. Dr. Gladwell did not advance a remoteness argument, and such an argument is not available on the facts of this case.

CONCLUSION

[93] I find it more likely than not that Dr. Gladwell did cause Mr. Dallner’s injury and did breach the standard of care by applying an excessive degree or duration of force or stretch on Mr. Dallner’s arm during the surgery. I therefore find for Mr. Dallner in this action.

COSTS

[94] If the parties cannot resolve the issue of costs, they should provide submissions in writing consisting of not more than two pages plus bills of costs, offers to settle, supporting dockets, etc. Plaintiff by December 6, 2024. Defence by December 13, 2024. No reply. Counsel may write me if they require an extension.

Chown, J

Released: November 25, 2024

1 Page 369. Page references in these end notes refer to the draft transcript. 2 30 degrees of adduction. Page 382. 3 If you are standing with your arm hanging down naturally, you put your shoulder in flexion by raising your arm straight forward, and extension by raising it straight back. 4 The conjoint tendon is shown but not labelled on Exhibit 7. It runs from the coracoid process to the coracobrachialis muscle. 5 Page 378. 6 I am using the phrase “spread the muscles apart” but at trial the phrase “blunt dissection” was often used. This means, “Separation of tissue layers, without cutting, along naturally separated structures”: see jointly submitted Glossary of Medical Terms. 7 Page 382. 8 Page 370. 9 Page 370. 10 Page 371. 11 Page 392. 12 Page 385. 13 The medial cord was primarily injured, the posterior cord was less injured, and the lateral cord was minimally injured during the surgery. Per Dr. Wilson, page 565. 14 Page 540. 15 Page 173; page 584. 16 Page 42; page 386. 17 Page 576; page 420. 18 Page 369. 19 Page 592. 20 Page 275. 21 Page 292. 22 Page 369. 23 Page 328. 24 Page 668. 25 Page 583. 26 Page 586. 27 Page 594. 28 Page 76, 78. 29 Page 684. 30 Page 647. 31 Page 76. 32 Page 76. 33 Page 646. 34 Page 327. 35 Page 402. 36 Page 432. 37 Page 585. 38 Page 481. 39 Page 480. 40 Page 619. 41 Page 619. 42 Page 682.