Inextricably Intertwined – Benson Revisited in California

Inextricably Intertwined – Benson Revisited in California

In their decision in Benson1 what exactly did the Court of Appeal and WCAB say about multiple claims or successive injuries being “inextricably intertwined” in determining apportionment of disability under Labor Code section 4663? Did the DCA and WCAB actually use the term “inextricably intertwined?” Can you say “inextricably intertwined” ten times fast with two Sapphire Tonics on board? The answers are “no, no and no!”

In order to fully understand the medical evidence on apportionment that a treating or evaluating physician is required to provide to the parties and ultimately to a judge, you have to understand exactly what the WCAB said about the duties of the physician in determining apportionment of disability and what happens if a physician can’t.

The Wilkinson Doctrine

The Wilkinson doctrine basically said that an employee who sustains successive industrial injuries to the same part of body, and becomes permanent and stationary at the same time, is entitled to one combined permanent disability award. The Wilkinson doctrine was based on Labor Code section 4750, which was repealed under SB-899 and replaced by current Labor Code sections 4663 and 4664 which require a determination of apportionment based on causation. Under the Benson decisions, the WCAB and later the DCA adopted the finding that the Wilkinson doctrine itself was intentionally repealed by the legislature in SB 899.

So now, if there are successive injuries to the same part of body then the physician must assume that in most cases, “apportionment based on causation requires that each distinct industrial injury be separately compensated based on its individual contribution to a permanent disability.” See Benson vs. WCAB, 74 Cal. Comp. Cases 113 at 133.

Labor Code section 4663(c)

On the question of what a physician is required to do in all cases in determining apportionment to prior industrial injuries, non-industrial factors and any subsequent industrial or non-industrial injuries, the DCA and WCAB cited Labor Code section 4663(c) which states as follows:

“In order for a physician’s report to be considered complete on the issue of permanent disability, the report must include an apportionment determination. A physician shall make an apportionment determination by finding what approximate percentage of the permanent disability was caused by the direct result of injury arising out of and occurring in the course of employment and what approximate percentage of the permanent disability was caused by other factors both before and subsequent to the industrial injury, including prior industrial injuries. If the physician is unable to include an apportionment determination in his or her report, the physician shall state the specific reasons why the physician could not make a determination of the effect of that prior condition on the permanent disability arising from the injury. The physician shall then consult with other physicians or refer the employee to another physician from whom the employee is authorized to seek treatment or evaluation in accordance with this division in order to make the final determination.”

The Benson Decisions

So when can a physician combine permanent disability from two distinct industrial injuries to the same part of body and avoid separate and distinct awards? Both the WCAB and the DCA, which adopted the WCAB en banc decision language, answer that question without using terms like “inextricably intertwined” as follows:

The DCA opinion states at 74 Cal. Comp. Cases 133:

“We also agree that there may be limited circumstances, not present here, when the evaluating physician cannot parcel out, with reasonable medical probability, the approximate percentages to which each distinct industrial injury causally contributed to the employee’s overall permanent disability. In such limited circumstances, when the employer has failed to meet its burden of proof, a combined award of permanent disability may still be justified. [citing Labor Code section 4663(c)] Kopping vs. WCAB (2006) 71 Cal. Comp. Cases 1229.”

The WCAB in its en banc decision and at fn 3 in the DCA opinion at 74 Cal. Comp. Cases 116 stated:

“We observe, however, that there may be limited circumstances, not present here, where the evaluating physician cannot parcel out, with reasonable medical probability, the approximate percentages to which each successive injury causally contributed to the employee’s overall permanent disability. Under these limited circumstances, a combined award of permanent disability may still be justified. In such an instance, the physician’s apportionment determination, within the meaning of Labor Code section 4663, could properly be that the approximate percentages of disability caused by each of the successive injuries cannot reasonably be determined. As a result, the employee would be entitled to an undivided (i.e. joint and several) award for the combined permanent disability, because the respective defendants would have failed in their burdens of proof on the issue of apportionment.” [again citing Kopping vs. WCAB].

So you can see, there is no discussion or use of “inextricably intertwined” or similar language used in either the DCA or WCAB en banc decisions. Now remember, the permanent disability involved in Wilkinson was two specific injuries to the applicant’s same knee, two months apart.

The permanent disability in Benson was to the applicant’s neck in a specific injury (a medical file clerk reaching for a file bin) and an eleven-year continuous trauma to the neck due to the repetitive use of the neck and upper extremities, resulting in a three-level spinal fusion. The permanent disability determinations in both Wilkinson and Benson relied on permanent disability rating schedules that were based on work restrictions and were not based on objective medical findings or impairments under the AMA Guides.

In looking at Dr. Izzo’s conclusions as the AME in Benson that 50% of the applicant’s permanent disability was due to the specific injury in June 2003 and 50% was due to continuous trauma seems to have been an after-thought more than as a result of careful medical analysis. Remember, there was no continuous trauma claim filed until after everyone received Dr. Izzo’s report! He could have simply concluded that the incident that occurred in June 2003 while reaching for the file bin was part of one injury – a continuous trauma – and Ms. Benson would have received her 61% award.

We are seeing this creativity when we ask physicians during depositions, “Didn’t one of these injuries cause 0% permanent disability and the other one caused the entire amount of permanent disability in this case?” What if Dr. Izzo had concluded that 99% of Ms. Benson’s permanent disability was caused by continuous trauma and 1% caused by the June 2003 incident? Would this have passed muster under Labor Code section 4663(c)? Probably so, if Dr. Izzo had explained how and why.

Benson and the AMA Guides

If Benson had involved a permanent impairment rating under the AMA Guides it is probable that Dr. Izzo would have been hard-pressed to even consider the June 2003 specific incident a separate and distinct injury from a cumulative trauma injury. Why? Because the extent of pathology that results in a three-level cervical fusion probably did not occur in one day nor does the impairment arising from it. How and why did he arrive at 50% to the specific and 50% to the continuous trauma in the first place?

It is empirically easier to “parcel out” percentages of causation of permanent disability when the disability is based on work restrictions than when it is based on permanent objective medical findings as now required under the AMA Guides. In Benson, how can any physician with reasonable medical probability say that the incident in June 2003 of reaching for a file bin caused any permanent impairment? Wasn’t the impairment already progressed from a pristine cervical spine to a diseased one that required a three-level fusion? In the absence of any specific pathology that can be linked to a specific injury, it is probably virtually impossible for any physician to determine causation of permanent disability in these cases.

This is even more complex when an impairment under the AMA Guides is not only caused by the industrial injuries themselves (such as two specific injuries in Wilkinson and a specific and continuous trauma injuries in Benson) but also by failed medical treatment afterwards, such as a chronic pain syndrome case that is caused by failed spinal surgery. No physician on this planet could “parcel out” permanent disability between successive injuries when the majority of the resulting impairment is caused by the medical treatment from both injuries.

There is a big problem under Benson when the permanent disability is based on impairment of function, anatomic loss, diagnosis based or from a combination of these factors as now required under the AMA Guides. How can anyone tell, with reasonable medical probability, that a herniated disc, entrapped median nerve (carpal tunnel syndrome), torn meniscus in knees or a torn rotator cuff in the shoulder are caused by successive injuries and “parceled out” as to causation of permanent disability? How do you say, “Speculation?”

The construct in Benson makes perfect sense from a legal standpoint when it comes to the intent of the legislature to require disability based on causation and to no longer allow evidence of rehabilitation from a prior award and to apportion to pathology, prior and subsequent injuries and retroactive prophylactic work restrictions. But it is another universe we have entered into when it comes to determining causation of impairment in successive injury cases to the same part of body.

Under the AMA Guides the impairment rating must be based on objective medical findings, limitation of function and a solid diagnosis, most of which cannot be distinguished if the cause is from successive injuries. There certainly must be some objective evidence in place between two successive injuries to justify a physician to “parcel out” apportionment between them under the AMA Guides. It would have been nice if Mr. Wilkinson had an MRI scan of his knee after the first injury and again after the second one so that his physician under the AMA Guides could have told us what percentage of impairment is caused by each injury, even though they occurred two months apart! Fortunately Mr. Wilkinson does not have to worry about the AMA Guides – you get the point.

What about the mandate under Labor Code section 4663(c) that says that if a physician cannot parcel out apportionment between successive injuries, he or she must consult with another physician or refer the applicant out to another treating or evaluating physician for that purpose? Does this mean defendants have a right to doctor shop until they find the right doctor to speculate about apportionment? What if an AME cannot parcel out the apportionment between successive injuries? After all, an AME becomes both parties’ physician under current law? See Green vs. WCAB (2005) 70 Cal. Comp. Cases 294 wherein the DCA stated:  “We agree with Green that the opinions of Drs. Weiss and Fauget as agreed medical examiners may result in liability for increased compensation under new section 5814. Green and City deferred the medical issues to Drs. Weiss and Fauget, whose opinions became in effect the opinions of each party’s physician under Berry” citing Berry vs. WCAB (1969) 34 Cal. Comp. Cases 507).

So there we have it. Every physician must try and parcel out apportionment between successive industrial injuries. If they cannot, they must say so and indicate that they have either consulted with another physician or referred the applicant to another physician to do so. All of this is required by Labor Code section 4663(c) and both decisions in Benson. Under the AMA Guides in many cases, it will be impossible for any physician to be able to make an apportionment determination between successive injuries because we are no longer dealing with work restrictions but are instead dealing with real medicine.

When you have successive injury cases, defense counsel must be sure to have these issues in mind and prepare to take the AME, panel QME or treating physician’s deposition. If defense counsel does not refute a physician’s conclusion that it is impossible to “parcel out” apportionment of permanent disability between successive injuries to the same part of body that becomes permanent and stationary at the same time, defendant fails to meet its burden of proving apportionment under Benson under the mandate of Kopping vs. WCAB and the applicant gets a combined award. We wish the WCAB or DCA had said this whole thing is “inextricably intertwined!”


1. Case citations for this article are: Benson vs. WCAB (2009) 170 Cal. App.4th 1535, 74 Cal. Comp. Cases 113; Benson vs. The Permanente Medical Group (2007) 72 Cal. Comp Cases 1620 (WCAB en banc decision), hereinafter called “Benson;” Brodie vs. WCAB (2007) 40 Cal.4th 1313, 72 Cal. Comp. Cases 565, hereinafter called “Brodie;” Wilkinson vs. WCAB (977) 19 Cal.3d 491, 42 Cal. Comp. Cases 406, hereinafter called “Wilkinson.”

 © 2010 Robert G. Rassp, Esq. All rights reserved. Reprinted with permission.