ADJ11142067 · March 6, 2026

The Board found that the QME Dr. Purcell's apportionment opinion was conclusory and vague, thus not substantial evidence, and instead relied on the parties' prior stipulation to Dr. Roth's opinion assigning 50% apportionment to left knee arthritis. Defendant failed its burden of proof on apportionment to other body parts. The Board awarded 54% permanent partial disability based on this reasoning.

From the decision · page 6First, the apportionment opinion of QME Dr. Purcell does not constitute substantial medical evidence as it is conclusory and without adequate explanation. Not only is it conclusory, but it is also vague as Dr. Purcell states that "other factors" caused disability without describing any such factors. The apportionment opinion of Dr. Purcell cannot be followed.

QME Dr. Purcell's apportionment opinion was conclusory and vague, lacking adequate explanation of 'other factors' causing disability

Favours Applicant prevailed

This led the Board to reject Dr. Purcell's opinion and rely on the parties' prior stipulation to Dr. Roth's opinion for apportionment, resulting in a higher permanent disability award for the applicant.

From the decision · page 6First, the apportionment opinion of QME Dr. Purcell does not constitute substantial medical evidence as it is conclusory and without adequate explanation. Not only is it conclusory, but it is also vague as Dr. Purcell states that "other factors" caused disability without describing any such factors. The apportionment opinion of Dr. Purcell cannot be followed.

Dr. Roth diagnosed left knee lateral meniscectomy with mild osteoarthritis and assigned 10% whole-person impairment to the left knee, apportioned 50% to industrial causation and 50% to pre-existing degenerative changes.

The Board relied on Dr. Roth's apportionment opinion as substantial evidence and the parties had stipulated to it.

From the decision · page 2Roth commented upon apportionment as follows: The industrial injury reasonably resulted in meniscal injury, and the associated disability attributed to partial meniscectomy would be apportioned entirely to the November 28, 2016 industrial injury. The claimant's overall level of permanent disability involving the left knee, however, is significantly increased because of underlying arthritic changes. It is my opinion the arthritic changes were aggravated as a result of the industrial injury and treatment for same. As a result of the combination of effects of the specific injury, underlying degenerative changes, and aggravation of same, the claimant has significantly greater permanent disability than would have been anticipated for a simple meniscal injury and partial meniscectomy. The cause of left knee permanent disability is apportioned 50% to industrial causation and aggravation and 50% to pre-existent underlying degenerative changes, which significantly increased the impairment rating.

Dr. Purcell diagnosed degenerative arthritis in both knees and hips and assigned various whole-person impairments. He opined 20% of impairment was caused by industrial injury and 80% by other factors but his apportionment opinion was found conclusory and vague by the Board.

The Board rejected Dr. Purcell's apportionment opinion as conclusory and lacking adequate explanation.

From the decision · page 3(Joint Exhibit 101, Report of QME Graham Purcell, M.D., May 10, 2021, p. 15.) He found that injury to the right knee and bilateral hips were a compensable consequence of gait derangement from the left knee. (Ibid.) He assigned 1% WPI for the left knee meniscectomy. (Id. at p. 16.) He assigned 10% WPI for left knee arthritis. (Ibid.) He assigned 10% WPI for left hip arthritis. (Ibid.) He assigned 20% WPI for right knee degenerative arthritis. (Ibid.) He assigned 10% WPI for right hip degenerative arthritis. (Ibid.) Dr. Purcell opined on apportionment, as follows: With regards to apportionment, there are medical records outlining approximately 4 years of physical therapy for symptoms of underlying degenerative joint disease. It is my medical opinion based on the diagnostic studies, the medical records available and the applicant own history to me, that 20% of her current impairment has been caused by the industrial injury of 11/28/2016 and 80% of her current impairment has been caused by other factors. (Id. at p. 17.)

Labor Code section 4663(c); Nunes v. State of California, Dept. of Motor Vehicles (Nunes I) (2023) 88 Cal.Comp.Cases 741; Escobedo v. Marshalls (2005) 70 Cal.Comp.Cases 604; Brodie v. Workers' Comp. Appeals Bd. (2007) 40 Cal.4th 1313; Ashley v. Workers' Comp. Appeals Bd. (1995) 37 Cal.App.4th 320

Apportionment must be determined by a physician and the WCAB using reasonable medical probability and substantial evidence, accounting for all factors before and after the industrial injury.

The Board applied these standards to reject Dr. Purcell's apportionment opinion and rely on Dr. Roth's prior stipulation for apportionment.

From the decision · page 4Section 4663(c) provides, in relevant part:

QME Dr. Purcell's apportionment opinion was conclusory and vague, lacking adequate explanation of 'other factors' causing disability

From the decision · page 6First, the apportionment opinion of QME Dr. Purcell does not constitute substantial medical evidence as it is conclusory and without adequate explanation. Not only is it conclusory, but it is also vague as Dr. Purcell states that "other factors" caused disability without describing any such factors. The apportionment opinion of Dr. Purcell cannot be followed.