The opinion of the court was delivered by: Frank C. Damrell, Jr. United States District Judge
This matter is before the court on defendants Zimmer US, Inc. and Zimmer Inc.'s ("defendants") motion for summary judgment pursuant to Federal Rule of Civil Procedure 56 and defendants' motion to exclude the testimony of Martin T. Wells ("Wells") pursuant to Federal Rule of Evidence 702.*fn1 For the reasons set forth below, defendants' motion for summary judgment is GRANTED in part and DENIED in part and defendants' motion to exclude Wells' testimony is DENIED.
Plaintiff Sara Monroe ("plaintiff") alleges that use of a Zimmer Ambulatory Pump ("ZAP")*fn3 caused her to lose cartilage in her shoulder, resulting in unbearable pain and suffering. (Complaint, filed Oct. 16, 2008.) Plaintiff raises claims under California law for: (1) general negligence; (2) negligent products liability; and (3) strict products liability. As to the claim of general negligence, plaintiff alleges that defendants negligently designed, manufactured, and distributed a defective ZAP and negligently failed to warn doctors and patients that use of the ZAP in shoulder joints was unsafe.
A. Anatomy of the Shoulder and the Glenohumeral Joint
The ball-and-socket joint of the shoulder is called the glenohumeral joint. The area surrounding the glenohumeral joint contains articular cartilage and synovial tissue. Articular cartilage is a thin layer of tissue that covers the ends of bones in the joint and provides a smooth, gliding surface that enables the bones to move. Articular cartilage receives its nutrients exclusively from synovial fluid within the joint space.
B. Glenohumeral Chondrolysis
Articular cartilage cells are known as chondrocytes. Chondrolysis is the destruction of these cells. Glenohumeral chondrolysis refers to rapid and permanent destruction of chondrocytes in the shoulder joint. See D.J. Solomon et al., Glenohumeral Chondrolysis After Arthroscopy: A Systematic Review of Potential Contributors and Causal Pathways, 25 ARTHROSCOPY: J.
ARTHROSCOPIC & RELATED SURG. 1329, 1330 (Nov. 2009). Cartilage cell death may occur from the inability of chondrocytes to maintain or produce cartilage matrix. Id. If the cartilage matrix is not renewed, it wears away with normal use of the joint until all of the protective tissue is gone. This results in the bones of the joint rubbing against one another, causing debilitating pain and stiffness.
A pain pump is a medical device designed to deliver targeted doses of pain management medication to a specific part of the body. A pain pump consists of a fluid reservoir that contains one or more pain medications, a mechanism that pumps the pain management medication to the patient, and a catheter that delivers the pain management medication to a specific part of the body.
2. Plaintiff's Medical History
On May 18, 2007, plaintiff's orthopedic surgeon, Dr. Richard Cross ("Cross"), performed surgery on plaintiff's left shoulder.
(Deposition of Dr. Richard Cross ["Cross Dep."], filed Sep. 23, 2010 [Docket #80], Ex. C at 23:5-7.)*fn5 The surgery involved decompression of the acromion and a resection of the distal clavicle. (Id. at 23:16-21; DUF ¶ 5.) Prior to the surgery, on May 10, 2007, Cross injected plaintiff's left shoulder with the anesthetic Marcaine.*fn6 (Cross Dep. at 12:3-7.) During the surgery, Cross found that plaintiff had a "degenerative or arthritic and/or arthritic acromioclavicular joint" and "some impingement in her shoulder or crowding of her acromion." (Id. at 23:10-13.) Cross noted that these issues were "not unusual" for a patient of plaintiff's age with plaintiff's medical background. (Id. at 23:25-24:4.)
Also on May 18, 2007, Cross used a radio frequency probe on plaintiff's glenoid, within the glenohumeral joint. (Id. at 71:15-25.) He used this probe, at a low frequency, to smooth a mild amount of damaged cartilage. (Id.) Cross noted that this damage was typical wear and tear damage for someone of plaintiff's age. (Id.)
Following the surgery on plaintiff's left shoulder, a ZAP was inserted into the subacromial space of plaintiff's left shoulder for a minimum of two days.*fn7 (DUF ¶¶ 7-8, 10; Cross Dep. at 30:4-7.) A fluid pathway from the ZAP catheter to plaintiff's glenohumeral joint should not have been present at this time; however, it is possible that such communication occurred. (DUF ¶ 9; Cross Dep. at 54:2-25.)
After plaintiff's surgery, she was involved in an altercation where she was punched in her left shoulder. (DUF ¶¶ 11-12.) This altercation delayed plaintiff's treatment and led to Cross injecting corticosteroids into plaintiff's glenohumeral joint. (DUF ¶¶ 14-15.)
On August 31, 2007, Cross performed a second surgery on plaintiff's left shoulder. (DUF ¶ 16.) During this surgery, Cross noted a lesion, labral tearing, and an onset of degenerative changes in the articular cartilage of plaintiff's glenoid. (DUF ¶ 17.) Cross also noted a Hill-Sachs lesion of the humerus during this surgery. (DUF ¶ 18; Cross Dep. at 52:11-25-53:1-5.) As he did during the first surgery, Cross used a radio frequency probe on the cartilage of plaintiff's glenoid. (DUF ¶ 20.)
During plaintiff's surgery on August 31, 2007, a ZAP was inserted directly into plaintiff's glenohumeral joint.*fn8
(DUF ¶ 21.) The ZAP remained in plaintiff's shoulder for six days. (Cross Dep. at 62:7-21.) After this surgery, plaintiff received two additional injections of corticosteroids into her glenohumeral joint. (DUF ¶ 22.)
After receiving the injections, plaintiff complained to Cross of increased pain and decreased range of motion in her shoulder. (Cross Dep. at 68:21-24.) Cross ordered an x-ray, which revealed global loss of cartilage in plaintiff's shoulder. (Id. at 69:2-6.) Plaintiff was subsequently diagnosed with chondrolysis in her left shoulder. (DUF ¶ 23.)
Testimony on the issue of the specific cause of plaintiff's injury comes from plaintiff's treating physician, Cross. Plaintiff disclosed Cross as a non-retained expert. (DUF ¶ 25.) Cross admits that he is not an expert on the development of chondrolysis, nor is he an expert on whether chondrolysis is caused by pain pumps. (DUF ¶ 26.) As discussed below, Cross states that he implemented the "differential diagnosis" method to determine the cause of plaintiff's injury.
Initially, Cross believed that plaintiff's chondrolysis resulted from her altercation. (DUF ¶ 27; Cross Dep. at 74:11-21.) It was not until January 24, 2008 that Cross determined that plaintiff's chondrolysis was "possibly" due to the ZAP. (Cross Dep. at 74:24-25-75:1-5.) Cross testifies that this change occurred because he was not previously aware of an association between chondrolysis and pain pump use. (Id. at 75:17-19.) Cross testifies that he is not entirely sure, but he believes that a "blurb" on the internet drew his attention to potential problems associated with the use of pain pumps. (Id. at 75:24-25-76:1-4.) Once he became aware of this potential association, Cross reports that it "clicked" for him, that the pain pump may be the cause of plaintiff's chondrolysis.
(Id. at 76:4-7.) During his deposition, defendants' counsel asked Cross if he ever formed an opinion that the pain pump was a substantial factor in causing plaintiff's chondrolysis. (Id. at 77:21-23.) Cross responded "[t]hats a good question. And I would say I think I have. I think I have, but it's not science. It's an opinion . . . it's my gut feeling with [plaintiff]." (Id. at 77:24-25, 78:2-3.)
Cross later elaborated on his thought process, discussing how he considered other factors that could have caused plaintiff's injury but ultimately ruled them out, eventually deciding that the pain pump may have been a significant cause of plaintiff's injury. (Id. at 78:4-25-79:1-13.) Cross also testified that, "if I could do it all over again, I never would've put a pain catheter in her. Whether we would've had this problem or not, who's to say? . . . Certainly you can argue that point." (Id. at 80:13-18.) Eventually, in response to questioning from plaintiff's counsel, Cross testified that it was his opinion, based on his review of medical literature, many years of orthopedic experience, and clinical experience with plaintiff, that the pain pump was "the most probable cause" of plaintiff's chondrolysis.*fn9 (Id. at 102:21-25-102:1-11.)
One of plaintiff's two retained experts on the issue of general causation is Dr. Jason Dragoo ("Dragoo"), a professor of Orthopedic Surgery at Stanford University. (Decl. of Dr. Dragoo ["Dragoo Report"], filed Feb. 19, 2010 [Docket # 29], Attachment 7 at ¶ 1.) Dragoo reviewed retrospective studies, case reports, and an in vivo animal study. Dragoo also conducted an in vitro human study, using articular cartilage from human knees and a "culture system" designed to replicate the normal physiology of the shoulder. (Dragoo Report ¶¶ 14-17.) Based on the results of his study and his review of prior studies, Dragoo determined, with a reasonable degree of medical certainty, that intraarticular pain pump usage can cause cartilage degeneration. (Id. at ¶ 31.)
Wells, the Chair of the Department of Statistical Sciences at Cornell University, is plaintiff's other expert on the issue of general causation. (Decl. of Martin T. Wells, Ph.D. ["Wells Report I"], filed Feb. 19, 2010 [Docket # 29], Attachment 3 at ¶ 2.) Wells reviewed epidemiological and scientific literature relating to intra-articular pain pump use and its connection to glenohumeral chondrolysis. (Wells Report I ¶ 1.) As discussed infra, Wells conducted statistical analysis on the data reported in these studies to determine whether they reported a statistically significant causal relationship between the use of intra-articular pain pumps and the development of chondrolysis. (Id. at ¶¶ 1, 14.)
In his analysis, Wells employed principles set forth in Bradford Hill's criteria of causation ("Hill analysis"), which are meant to assess the presence of a meaningful, statistically valid association between phenomena. (Id. at ¶ 14.) Wells' statistical analysis led him to conclude that there is a substantial difference in the risk of developing chondrolysis for patients that use a pain pump versus patients who do not. Wells also analyzed the data to determine whether other potential risk factors could be responsible for the development of chondrolysis, ultimately ruling them out.
The Federal Rules of Civil Procedure provide for summary judgment where "the movant shows that there is no genuine dispute as to any material fact and the movant is entitled to judgment as a matter of law." Fed. R. Civ. P. 56(a). The evidence must be viewed in the light most favorable to the nonmoving party.
See Lopez v. Smith, 203 F.3d 1122, 1131 (9th Cir. 2000) (en banc).
The moving party bears the initial burden of demonstrating the absence of a genuine issue of fact. See Celotex Corp. v. Catrett, 477 U.S. 317, 325 (1986). If the moving party fails to meet this burden, "the nonmoving party has no obligation to produce anything, even if the nonmoving party would have the ultimate burden of persuasion at trial." Nissan Fire & Marine Ins. Co. v. Fritz Cos., 210 F.3d 1099, 1102-03 (9th Cir. 2000).
However, if the nonmoving party has the burden of proof at trial, the moving party only needs to show "that there is an absence of evidence to support the nonmoving party's case." Celotex Corp., 477 U.S. at 325.
Once the moving party has met its burden of proof, the nonmoving party must produce evidence on which a reasonable trier of fact could find in its favor viewing the record as a whole in light of the evidentiary burden the law places on that party. See Triton Energy Corp. v. Square D Co., 68 F.3d 1216, 1221 (9th Cir. 1995). The nonmoving party cannot simply rest on its allegations without any significant probative evidence tending to support the complaint. See Nissan Fire & Marine, 210 F.3d at 1107. Instead, the nonmoving party must cite to "particular parts of materials in the record," or show that moving party's cited materials "do not establish the absence or presence of a genuine dispute, or that an adverse party cannot produce admissible evidence to support the fact." Fed. R. Civ. P. 56(c)(1).
The admissibility of expert testimony is governed by Federal Rule of Evidence 702 ("Rule 702"). When specialized knowledge will assist the trier of fact to understand the evidence in a case, Rule 702 permits testimony by experts with the knowledge, skill, experience, training, or education necessary to testify thereto, as long as their testimony meets several requirements. Fed.R.Evid. 702. A qualified expert's testimony is admissible if: (1) the testimony is based upon sufficient facts or data; (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case. Id.
The role of the trial judge is to act as a gatekeeper, ensuring that only relevant and reliable testimony is admitted. See Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579, 589 (1993) ("Daubert I"); see also Kumho Tire Co., Ltd. v. Carmichael, 526 U.S. 137, 152 (1999). Accordingly, the court must conduct a "preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid and of whether that reasoning or methodology properly can be applied to the facts in issue." Daubert I, 509 U.S. at 592-93. "Pertinent evidence based on scientifically valid principles will satisfy those demands." Id. at 597.
In Daubert I, the Supreme Court listed several key considerations to aid the trial court in its gatekeeping role. The trial court should consider: (1) whether the scientific knowledge can or has been tested; (2) whether the given theory or technique has been published or subjected to peer review; (3) the potential or known error rate; and (4) whether the theory or technique has gained general acceptance in the pertinent field. Daubert I, 509 U.S. at 592-94.
The court's Rule 702 analysis is flexible. Kumho Tire Co., Ltd. v. Carmichael, 526 U.S. 137, 150 (1999). The court may consider any or all of the Daubert I factors, depending on the "particular circumstances of the particular case at issue." (Id.)
The trial court may dismiss testimony that is either irrelevant or unreliable. See Stilwell v. Smith & Nephew, Inc., 482 F.3d 1187 (9th Cir. 2007). In evaluating the expert's testimony, the court must focus on the principles or methodology involved, not the conclusions that they generate. Daubert I, 509 U.S. at 595. Thus, "the test under Daubert is not the correctness of the expert's conclusions but the soundness of his methodology." Daubert v. Merrell Dow Pharms., Inc., 43 F.3d 1311, 1318 (9th Cir. 1995) ("Daubert II"). "Ultimately, the court must ensure that an expert "employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field," such that the expert's "work product amounts to 'good science.'" McClellan v. I-Flow Corp., 710 F. Supp. 2d 1092, 1100 (D. OR. 2010) (quoting Kumho, 526 U.S. at 152 and Daubert II, 43 F.3d at 1315).
Defendants move for summary judgment, arguing that plaintiff's claims fail because her experts are unable to prove that the ZAP is capable of causing chondrolysis generally, or that the ZAP specifically caused plaintiff's injury. Further, defendants assert that plaintiff's claims should be dismissed because she has not demonstrated that defendants breached a specific duty of care to her.
Preliminarily, defendants attack the testimony of Wells, one of plaintiff's experts on general causation. As the resolution of defendants' motion for summary judgment turns, in large part, on whether plaintiff has sufficient, admissible evidence to establish that intra-articular use of a pain pump can cause chondrolysis, the court addresses defendants' motion to exclude Wells' testimony first, as without Wells' testimony, plaintiff cannot prevail on the motion. Second, because the court denies defendants' motion to exclude Wells' testimony, it next considers defendants' motion for summary judgment.
1. Motion to Exclude Wells' Testimony
Plaintiff offers Wells' testimony as proof that intraarticular use of pain pumps can cause glenohumeral chondrolysis. Defendants move to exclude Wells' testimony, stating that (1) he is not qualified to opine on the cause of glenohumeral chondrolysis, and (2) his testimony is ...