The employer and insurer appeal from the compensation judge’s decision that the employee sustained a Gillette injury to his right knee culminating on November 3, 2005, which substantially contributed to his need for right knee surgery, related medical expenses, and temporary total disability benefits.  The employer and insurer also appeal from the compensation judge’s determination that the employee provided proper statutory notice of his November 3, 2005, right knee injury.  We affirm.

The employee began working for Northwestern Refining Company, the predecessor company to Marathon Petroleum Company [the employer], in June 1967.  Initially he was employed in the operations department, working in maintenance as a welder and mechanic.  He later worked as a crane operator and was promoted to warehouse material handler, otherwise referred to as a warehouseman, a position he has held since 1977.

The employee’s work as a warehouseman involved the receipt, storage, retrieval and distribution of refinery equipment.  Receipt of equipment involved unloading the equipment, tools, supplies and other packages from various delivery trucks, verifying the contents and physically moving the items to storage shelving; these tasks often necessitated the use of forklifts.  He issued equipment requested by various departments, which involved physically retrieving equipment and items from either storage shelving or the mezzanine level, and transporting the items to the staging areas for delivery.  At times, he also delivered the items to the delivery destination, generally on the refinery premises.  His job also involved shipping, which included preparing the shipping cartons and packaging them for shipment.^[1]  The employee described his work as involving frequent walking; since the early 1990s, he also had available to him and used an electric golf cart to travel in the warehouse.  At times, he operated various types of warehouse equipment, including forklifts, two-wheel hand carts, pallet jacks and pick-up trucks.

Over time, the employee’s right knee condition deteriorated, and by late 1996 his surgeon, Dr. Peter Daly, diagnosed the employee as having osteoarthritis in his right knee.^[2]  Dr. Daly initially recommended injections, but the employee’s knee condition had worsened to such a degree that Dr. Daly ultimately recommended an arthroscopic surgery, in the nature of a meniscectomy.  The employee underwent that surgery on January 2, 1997, and, within four weeks, he returned to work without restrictions.  His right knee condition had improved after the surgery, but within less than a year the employee again experienced right knee pain.  Although he did not seek medical treatment between 1997 and 2005, according to the employee his pain worsened over time, and he walked with a limp due to his deteriorating right knee condition.  His knee pain lessened overnight and on weekends when he was away from work, but resumed once he began working.

By mid-August 2005, the employee consulted Dr. Lawrence Lorbiecki, reporting persistent and worsening right knee pain.  An x-ray of his right knee showed moderate osteoarthritis with narrowing of the right medial compartment in the right knee.  Dr. Lorbiecki diagnosed degenerative joint disease, and referred the employee to Dr. James Gannon, who diagnosed right knee osteoarthritis, and recommended and then performed right knee replacement surgery on November 9, 2005.  The employee remained off work for six months post-surgery, and also underwent physical therapy.

One of the disputes on appeal is whether the employee provided timely statutory notice of his claimed right knee injury to the employer.  The employee testified that in August 2005, the employee met with his supervisor during a performance review, and informed his supervisor that the reason he was not performing the shipping function of his job was that those particular work duties caused him too much pain in his right knee.  In March 2006, the employee notified the employer through a written letter that he had undergone knee replacement surgery, and therefore had been off work since November 3, 2005, that it may or may not be work-related, and that the matter was being investigated to make a determination.  (Employer and Insurer Exh. 12.)  On March 15, 2006, the employee also completed an occupational injury and illness report in which he reported his alleged November 3, 2005, right knee injury that was caused by an accumulation of years of walking on concrete floors, climbing in and out of fork trucks, climbing stairs and ladders, and other warehouse related duties.  (Employer and Insurer Exh. 13.)  The employer completed a first report of injury form on March 16, 2006, which included the description listed on the occupational illness and injury report.  The insurer filed a notice of insurer’s primary liability determination, denying the alleged November 3, 2005, injury.

By April 26, 2006, Dr. Gannon released the employee to return to work without restrictions.  On May 4, 2006, the employee filed a claim petition, seeking benefits as a result of his claimed Gillette injury.  In a report dated May 12, 2006, Dr. Gannon, provided his opinion that “I believe that all treatment to date was reasonable and necessary as related to [the employee’s] original work-related injury and subsequent Gillette-type injury.  Again, I think it is clear that the repetitive microtrauma sustained over the past nine years in combination with [the employee’s] original knee injury led to his need for the total knee arthroplasty performed in November 2005.”

On July 14, 2006, Dr. Paul Dworak conducted an independent medical examination of the employee.  In his report, he concluded that in his “professional medical opinion, . . . [the employee’s] employment at Marathon Petroleum absolutely did not cause his degenerative joint disease of his right knee.”  He found no specific injury that occurred to the employee’s knee while
employed at Marathon Petroleum, and attributed the employee’s osteoarthritis in his right knee to heredity^[3] and perhaps the employee’s weight which may have prematurely aggravated his predisposition for the arthritis.

In a letter dated March 21, 2007, Dr. Gannon again outlined his opinion concerning the cause of the employee’s right knee condition.  He reviewed Dr. Dworak’s report, and commented that the background information outlined by Dr. Dworak, his history from the employee, his physical examination findings and x-ray review, were all consistent with his own understanding of the case.  Dr. Gannon reiterated his opinion that the employee’s right knee condition resulted from repetitive trauma to his knee associated with his work duties.  He explained that

On March 27, 2007, the employee’s claim was addressed at an evidentiary hearing.  At the hearing, the parties stipulated that the employee’s claimed temporary total disability benefits, permanent partial disability benefits, medical expenses and intervention claims were “reasonable, necessary and undisputed except with regard to the defenses of primary liability and notice.” (Stip. No. 3, Findings and Order.)

In his findings and order, served and filed on May 29, 2007, the compensation judge determined that the employee had sustained a Gillette injury to his right knee culminating on November 3, 2005, and that his right knee condition and need for a total right knee replacement resulted from a significant aggravation and acceleration of his preexisting degenerative joint disease which was caused, in substantial part, by his work activities since 1997.  The compensation judge also found that the employer had received proper statutory notice of the employee’s November 3, 2005, right knee injury.  He awarded the claimed temporary total disability and permanent partial disability benefits, as well as medical expenses related to treatment for the right knee.

The employer and insurer appeal from the compensation judge’s findings and order, arguing both that there was no causal relationship between the employee’s employment and his right knee condition and that they did not receive proper statutory notice of the employee’s claimed right knee injury.

To prove a claim under the Workers’ Compensation Act, an employee must show that the employer had timely notice or knowledge of the employee’s injury within the statutory period.  Issacson v. Minnetonka, Inc., 411 N.W.2d 865, 40 W.C.D. 270 (Minn. 1987).  Minn. Stat. § 176.141 outlines the time requirements for providing notice to an employer of a work-related injury.  Where notice is provided to the employer more than 30 days but less than 180 days from the occurrence of the injury, compensation is still payable if the employee “shows that failure to give prior notice was due to the employee’s . . . mistake, inadvertence, ignorance of fact or law, or inability, or to the fraud, misrepresentation, or deceit of the employer or agent . . . unless the employer shows prejudice . . . .”  Minn. Stat. § 176.141.  The purpose of the notice requirement is to permit the employer to make such investigation as is necessary to determine its liability for a compensation claim and to allow the employer to provide necessary medical care.  Rinne v. W.C. Griffis Co., 234 Minn. 146, 47 N.W.2d 872, 16 W.C.D. 348 (1951); see also Kling v. St. Barnabas Hosp., 291 Minn. 257, 261, 190 N.W.2d 674, 677, 26 W.C.D. 53, 56 (1971), citing Pojanowski v. Hart, 288 Minn. 77, 178 N.W.2d 913, 25 W.C.D. 206 (1970).  In cases involving a Gillette injury, the period during which notice must be given does not begin to run until the employee, as a reasonable person, should have recognized the probable compensability of the injury.  See Swenson v. Cal-Mech, 50 W.C.D. 1, 11 (W.C.C.A. 1993) (employee not aware of compensable nature of injury until medical report received).

The employer and insurer argue that the employee believed that as early as 1996 his right knee condition was aggravated by his work activities, or, alternatively, that the employee believed in August 2005 that his work activities were causing his knees symptoms to worsen, but  provided the employer with written notice of his injury later than the statutorily-required 180 days from the date of injury.  The compensation judge addressed these arguments in his memorandum, and concluded that the employer, in effect, had constructive notice of the employee’s condition and of the employee’s belief that his condition was related to his work activities.  The judge concluded that this notice was provided over the years by the progressive and apparent worsening of the employee’s right knee condition since 1996, his discussions with supervisors, and his notice of his impending total knee replacement surgery.  The compensation judge cited to various times or instances when the employer had received notice of the injury from the employee, including during a meeting between the employee and his supervisor in August 2005, from a letter the employee sent to the employer in March 2006 following his right knee surgery, and through an “occupational injury and illness report” completed by the employee on March 15, 2006. (Employer and Insurer’s Exhibit No. 13.)  The compensation judge also referred to the opinion of the employee’s treating orthopedic surgeon, Dr. Gannon, about the cause of the employee’s right knee condition, which he found to be persuasive.^[4]  The compensation judge concluded that

“The notice requirement is designed to enable the employer to furnish immediate medical attention in the hope of minimizing the seriousness of the injury as well as to protect the employer by permitting him to investigate the claim soon after the injury.”  Sobczyk v. City of Duluth, 245 Minn. 569, 73 N.W.2d 795, 19 W.C.D. 263 (1955).  In this case, the employee has worked for the employer and its predecessor since 1967.  He had claimed a right knee injury in 1996, which was denied by the employer and insurer and was not pursued at that time by the employee, for personal and family reasons.  The employee testified that his right knee continued to bother him, that his symptoms worsened, and that the employer was aware of his medical condition.  Under these particular circumstances, the compensation judge could reasonably conclude that the employer had received constructive notice of the employee’s right knee condition.  In addition, the employee’s actual notice of his Gillette injuries, culminating in November 2005, was provided within 180 days of the claimed culmination date, through the employee’s completion of an occupational injury and illness report.  The compensation judge did not err by finding that the employee had given adequate notice under Minn. Stat. § 176.141.  Accordingly, we affirm.

A Gillette injury is a result of repeated trauma or aggravation of a preexisting condition which results in a compensable injury when the cumulative effect is sufficiently serious to disable an employee from further work.  Gillette v. Harold, Inc., 257 Minn. 313, 321-22, 101 N.W.2d 200, 205-06, 21 W.C.D. 105 (1960); Carlson v. Flour City Brush Co., 305 N.W.2d 347, 350, 33 W.C.D. 594, 598 (Minn. 1981).  The question of a Gillette injury primarily depends on medical evidence.  Marose v. Maislin Transport, 413 N.W.2d 507, 512, 40 W.C.D. 175 (Minn. 1987).  The employee "must prove a causal connection between [his] ordinary work and ensuing disability . . . .  Whether given by testimony or written report, an opinion by a medical expert as to the causal link between the claimant's disability and the job must be based on adequate foundation."  Steffen v. Target Stores, 517 N.W.2d 579, 582, 50 W.C.D. 464, 467 (Minn. 1994).

The compensation judge found that the employee’s Gillette injury to his right knee, which culminated in disability on November 3, 2005, represented a substantial contributing cause to his current condition.  Relying on the medical opinion of Dr. Gannon and on the employee’s testimony concerning the nature of his work, the judge concluded that the employee’s right knee condition had progressively worsened after his 1997 surgery as a result of his repetitive work activities, and that “the employee’s work activities since 1997 were a substantial contributing factor in the aggravation of his preexisting right knee condition.”  The compensation judge specifically stated that he found Dr. Gannon’s causation opinion to be more persuasive than that of Dr. Dvorak.

The employer and insurer appeal, arguing that the employee did not prove he sustained a Gillette injury to his right knee that culminated on November 3, 2005.  They contend that the employee “failed to meet his burden of proof that his predominantly sedentary job aggravated his pre-existing degenerative arthritis of the right knee.”  They also contend that the compensation judge did not explain what specific job duties would have caused the employee’s Gillette injury to his right knee, and that the employee submitted “no evidence which showed how the little walking he did during the work day was any more stressful than walking at home or walking in any other regular daily activity,” nor any explanation of “what it was about the work environment that increased the downward force on the knee.”  The employer and insurer also argue that the record contains no medical opinion that rebuts Dr. Dvorak’s opinion on causation and his opinion that walking and activity actually could have slowed the degeneration in the employee’s knee.

It appears that the employer and insurer’s arguments are based, at least in part, on a theory or standard that is no longer the law.  From March 1985 until June 1994, the standard applied in proving and finding a Gillette injury was articulated in this court’s decision in Reese v. North Star Concrete, 38 W.C.D. 63 (W.C.C.A. 1985).  In Reese, this court indicated that, in order to prove a Gillette injury, an employee must be able to demonstrate “that specific work activity caused specific symptoms which led cumulatively and ultimately to disability constituting personal injury due to work."  Id. at 66.  In 1994 the supreme court overturned the standard set out in Reese, and held that, “[w]hile that kind of evidence may be helpful” in proving a Gillette injury, “the question of a Gillette injury primarily depends on medical evidence.”  Steffen v. Target Stores, 517 N.W.2d 579, 581, 50 W.C.D. 464, 467 (Minn. 1994).  As we noted in Scharber v. Honeywell, Inc., slip. op. (W.C.C.A. May 22, 2000):

As the supreme court held in Steffen, “the question of a Gillette injury primarily depends on medical evidence.” In this case, the record contains medical records documenting treatment since the early 1990s.  Those medical records, as well as the employee’s testimony and the opinions of medical experts, were available for the compensation judge’s review.  The judge reviewed the causation opinions of both Drs. Gannon and Dvorak, and found the opinion of Dr. Gannon to be more persuasive than that of Dr. Dvorak.  It is the compensation judge's responsibility, as trier of fact, to resolve conflicts in expert testimony, and, in this case, the compensation judge relied on Dr. Gannon’s opinion, that the employee’s right knee condition is causally related to his work activities.  See Nord v. City of Cook, 360 N.W.2d 337, 342, 37 W.C.D. 364, 372 (Minn. 1985).

It is the role of this court to determine whether “the findings of fact and order [are] clearly erroneous and unsupported by substantial evidence in view of the entire record as submitted.”  Minn. Stat. § 176.421, subd. 1.  Substantial evidence supports the findings if, in the context of the entire record, “they are supported by evidence that a reasonable mind might accept as adequate.”  Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984).  Upon review, we determine that an adequately founded medical opinion from Dr. Gannon, in conjunction with the employee’s medical records and the employee’s testimony concerning his job activities, provided sufficient support for the compensation judge’s finding concerning that the employee sustained a Gillette injury to his right knee that culminated on November 3, 2005, and that his injury substantially contributed to his current right knee condition, his need for medical treatment and surgery for his right knee, and his resulting disability from work.  We therefore affirm those findings.