ADJ15113297 · January 3, 2025

The WCJ and WCAB found Dr. Borelli's apportionment opinion on the right hip to be substantial medical evidence and consistent with legal standards, supporting 90% nonindustrial apportionment and 10% industrial causation.

From the decision · page 6As early as 03/26/2019, the patient had moderate degenerative x-ray changes in the right hip and had already undergone a left total hip replacement. These factors indicate that the vast majority of the patient's impairment is due to factors that predate the work injury. Clearly, the degenerative changes seen will inextricably lead to end-stage osteoarthritis in (sic) the need for hip replacement. It is my best clinical estimate that 90% of her right hip and impairment is due to factors that predate the work injury and the remaining 10% is due to the specific work injury. (Exhibit Y2, PQME report of Lawrence Borelli, M.D. dated 3/3/2023, page 17).

Applicant had moderate degenerative changes in the right hip and prior left total hip replacement before the industrial injury.

Favours Defendant prevailed

These preexisting conditions supported Dr. Borelli's apportionment that 90% of the right hip disability was due to nonindustrial factors.

From the decision · page 6As early as 03/26/2019, the patient had moderate degenerative x-ray changes in the right hip and had already undergone a left total hip replacement. These factors indicate that the vast majority of the patient's impairment is due to factors that predate the work injury. Clearly, the degenerative changes seen will inextricably lead to end-stage osteoarthritis in (sic) the need for hip replacement. It is my best clinical estimate that 90% of her right hip and impairment is due to factors that predate the work injury and the remaining 10% is due to the specific work injury. (Exhibit Y2, PQME report of Lawrence Borelli, M.D. dated 3/3/2023, page 17).

Dr. Borelli opined that 90% of the applicant's right hip permanent disability was due to nonindustrial factors and 10% due to the industrial injury, based on examination and review of medical records including MRI and prior hip replacement.

Dr. Borelli's opinion was found to be substantial medical evidence consistent with legal standards for apportionment, supported by diagnostic tests and prior medical history.

From the decision · page 6As early as 03/26/2019, the patient had moderate degenerative x-ray changes in the right hip and had already undergone a left total hip replacement. These factors indicate that the vast majority of the patient's impairment is due to factors that predate the work injury. Clearly, the degenerative changes seen will inextricably lead to end-stage osteoarthritis in (sic) the need for hip replacement. It is my best clinical estimate that 90% of her right hip and impairment is due to factors that predate the work injury and the remaining 10% is due to the specific work injury. (Exhibit Y2, PQME report of Lawrence Borelli, M.D. dated 3/3/2023, page 17).

Labor Code sections 4663 and 4664; Brodie v. WCAB (2007); City of Petaluma v. WCAB (2018); City of Santa Clara v. WCAB (2020)

Apportionment of permanent disability must be based on causation, with employer liable only for the percentage directly caused by the industrial injury.

The WCJ and WCAB applied these standards to find Dr. Borelli's apportionment opinion substantial and legally valid.

From the decision · page 5Labor Code section 4663(a) provides that apportionment of permanent disability shall be based on causation. Section 4664(a) states that the employer shall only be liable for percentages of permanent disability directly caused by the industrial injury. As stated in Brodie v. WCAB (2007) 40 Cal. 4th 1313, the new approach to apportionment is to look at the current disability and parcel out its causative sources- nonindustrial, prior industrial and current industrial- and decide the amount directly caused by the current industrial source. (Brodie, supra 40 Cal.4th, page 1328). Section 4663(b) requires that a report determining permanent disability also requires a determination of apportionment. The physician shall make a finding of apportionment based on the industrial cause, and also determine the percentage caused by other factor both before and subsequent to the industrial injury. Such other factors may include pathology and asymptomatic prior conditions. City of Petaluma v. WCAB, (2018) (Lindh) 29 Cal. App.5th 1175, at page 1184): City of Santa Clara v. WCAB (Justice) (2020) 40 Cal. App. 5th 605, 84 CCC 467.

Dr. Borelli's detailed medical examination and review of MRI and prior hip replacement history

From the decision · page 6As early as 03/26/2019, the patient had moderate degenerative x-ray changes in the right hip and had already undergone a left total hip replacement. These factors indicate that the vast majority of the patient's impairment is due to factors that predate the work injury. Clearly, the degenerative changes seen will inextricably lead to end-stage osteoarthritis in (sic) the need for hip replacement. It is my best clinical estimate that 90% of her right hip and impairment is due to factors that predate the work injury and the remaining 10% is due to the specific work injury. (Exhibit Y2, PQME report of Lawrence Borelli, M.D. dated 3/3/2023, page 17).