Based on substantial and competent evidence, including the above findings of fact, Claimant's testimony, and the expert opinions I find most credible, as well as the Law of the State of Missouri, I find and rule as follows:
- Claimant's work injury of October 23, 1998 is not a substantial factor in her CMC joint arthritis of the thumbs.
Under Missouri law, it is well-settled that the claimant bears the burden of proving all the essential elements of a workers' compensation claim, including the causal connection between the accident and the injury. Shelton v. City of Springfield, 130 S.W.3d 30, 38 (Mo.App. S.D. 2004)(citations omitted). Under § 287.020.2, an injury is compensable if it is clearly work-related. That section explains that "[a]n injury is clearly work related if work was a substantial factor in the cause of the resulting medical condition or disability," and "[a]n injury is not compensable merely because work was a triggering or precipitating factor." Loven v. Greene County, 94 S.W.3d 475, 478 (Mo.App. S.D. 2003). Section 287.020.3(2)(a) provides, in part, that an injury is deemed to arise out of and in the course of the employment if, among other things, it is reasonably apparent, upon consideration of all the circumstances, that the employment is a substantial factor in causing the injury. Loven at 478. "Medical causation, not within the common knowledge or experience, must be established by scientific or medical evidence showing the cause and effect relationship between the complained of condition and the asserted cause." Williams v. DePaul Health Center, 996 S.W.2d 619, 631 (Mo. App. E.D. 1999)overruled in part by Hampton v. Big Boy Steel Erection, 121 S.W.3d 220, 226 (Mo. 2003). When medical theories conflict, deciding which to accept is an issue peculiarly for the determination of the [factfinder]. Hawkins v. Emerson Elec. Co., 676 S.W.2d 872, 877 (Mo.App. S.D. 1984).
The overwhelming, uncontroverted evidence establishes the condition with which Claimant now suffers in her hands is CMC joint arthritis at the left thumb. Claimant also has symptoms in the right had due to non-unified arthrodesis at the thumb CMC joint, which represents a failed attempt to address the CMC joint arthritis at the right thumb. Thus, the initial issue is whether the work accident was a substantial factor in causing Claimant's CMC joint arthritis. On this critical issue, I find the work accident was not a substantial factor in the cause of the CMC joint arthritis.
The factual evidence does not establish the work accident was a substantial factor in the cause of Claimant's CMC joint arthritis. X-rays show the arthritis on the left side progresses from "no abnormalities" in November 1998 to "moderate" degenerative changes at the thumb CMC joint as of December 22, 2003, and "advanced osteoarthritis" on November 25, 2004. On the right side, degenerative changes were "mild" in September 1999, but on February 23, 2002, x-rays showed moderate narrowing at the thumb CMC joint. Thus, the disease was clearly progressive and chronic. Although Claimant had acute pain, particularly on the left side, immediately following the accident, those symptoms, which were related to de Quervain's tenosynovitis, discussed below, improved following surgery. As of late 1999, Dr. Strege noted the de Quervain's symptoms had essentially resolved, and the remaining complaints were related to thumb CMC joint arthritis.
The credible medical opinion evidence does not support a finding of causation. I find the opinion of Dr. Strege, the treating physicin, the most credible, clear and consistent with the evidene. He felt the cause of Claimant's bilateral CMC joint arthritis was "multifactoral," and her employment with Employer was a triggering factor as to part of the
cause of this arthritis, as opposed to a substantial or significant factor. In other words, work was a factor, but not the primary factor. Dr. Brown provided additional details as to cause, stating the prevalence of the condition in women over 40 years old, and the disease's relationship to aging. Agreeing cause of osteoarthritis is multifactoral, and it is a "wear and tear disease," Dr. Schlafly concluded "the injury of October 23, 1998 is the substantial and prevailing factor in the cause of the persistent pain coming from the CMC joint at the base of the left thumb," but failed to offer a lucid explanation as to how or why he so concluded. I particularly find fault because left symptoms were not "persistent" from the date of injury, but rather improved with treatment of the de Quervain's, and thereafter worsened as the CMC joint arthritis followed it's natural progression.
I find Claimant has symptomatic, bilateral CMC joint arthritis of the thumbs which is caused by factors other than her work accident of October 23, 1998. The facts established, and the experts explained, the disease is a chronic, progressive condition of wear and tear on the joint due to every day life, and not one traumatic event in particular. Even if the accident directly or indirectly triggered symptoms in Claimant's thumbs, I find that it did not make a substantial contribution. As such, the October 1998 accident was not a substantial factor in either the cause of the arthritis, or the onset of the painful symptoms. As such, Claimant has not established a causal connection between the October 1998 accident and the arthritic condition for which she seeks benefits.
While the work accident did not cause the CMC joint arthritis, the evidence does establish Claimant was injured as a result of her October 23, 1998 work accident. Claimant developed de Quervain's tenosynovitis as a result of the accident. She required treatment, including surgery on the left arm. While successful in alleviating the de Quervain's symptoms, the surgery was invasive and left her with scaring. The de Quervain's tenosynovitis is a condition in which the work accident was a substantial factor, and for which Claimant is entitled to compensation.