AMA Guides Fifth Edition Figure 15-19: Strict or Alternative WPI Rating?

AMA Guides Fifth Edition Figure 15-19: Strict or Alternative WPI Rating?

  By Robert G. Rassp, Esq.
Figure 15-19 on page 427 of the AMA Guides Fifth Edition has been frequently used by physicians to describe lumbar or cervical spine impairments based on the partial loss of function of a sub-region of the spine. This is due to the footnote under the drawing that states: “The whole spine divided into regions indicating the maximum whole person impairment of one region of the spine. Lumbar 90%, thoracic 40%, cervical 80%.”
The text at the top of page 427 describes how a physician can take a DRE or ROM WPI impairment rating and convert it to a “regional impairment” using Figure 15-19. However, the text on page 427 does not explain the reason why the footnote under Figure 15-19 exists. Some of the politics of the AMA Guides may be evident here.
Remember, the AMA Guides is a consensus derived document that was edited by occupational medicine physicians and not by orthopedic surgeons. In the case of Figure 15-19, there is language on page 9 of the AMA Guides that indirectly refers to the footnote under Figure 15-19. That language should actually be on page 427 but is not. The fact of the matter is that regional impairments are permitted by the authors of the AMA Guides. In section 1.3, on page 9, the authors write:
“Within some musculoskeletal regions, a consensus group developed weights to reflect the relative importance of certain regions. For example, different fingers or different areas of the spine are given different weights, representing their unique and relative importance to the region’s overall functioning. These weights, which have gained acceptance in clinical practice, have been retained to enable regulatory authorities to convert from a regional body to WPI when needed.”
What catches your eye in this language is the reference to the “weight” of a spinal region that represents the “relative importance to the region’s overall functioning.” That language, coupled with the footnote under Figure 15-19 that indicates the “maximum whole person impairment of one region of the spine”, justifies use of Figure 15-19 in certain cases. In workers’ compensation law we are always looking for WPI ratings that appear to be based on a loss of function since the orthopedic Chapters 15, 16 and 17 are mostly lacking any mention of loss of function in the listed WPI ratings.
Some physicians, for example, are taking a patient who has had five lumbar spinal surgeries including a two level fusion with a poor result and assigning a 36% WPI based on Figure 15-19. The rationale for this is that since the lumbar spine has five levels and the maximum value of the lumbar spinal region is 90% WPI, the loss of two levels from a fusion is 18% WPI per level or 36% WPI. A WCAB panel accepted this rating method as “within the four corners of the AMA Guides” as the most accurate rating in Laury vs. R&W Concrete Contractors, 2011 Cal. Wrk. Comp. P.D. LEXIS 77.
The majority panel in Laury justified use of Figure 15-19 in this case resulting in a 54% WPI rating because:
“Figure 15-19 is within the four corners of the Guides. Moreover, in affirming our en banc holding in Almaraz-Guzman II, the Court of Appeal recently stated that “the language of section 4660 permits reliance on the entire Guides including a physician’s use of clinical judgment in deriving an impairment rating in a particular case [citation to Milpitas omitted].”
The panel pointed out the permanent objective medical findings in this case as required on page 1-4 of the 2005 PDRS:
“Here, applicant has undergone a total of five spinal procedures. First he underwent a laminectomy at L5-S1 but suffered a spinal fluid leak. As a result, he underwent two follow-up surgeries. When his symptoms returned, he underwent a battery of diagnostic testing and received epidural steroid injections. Applicant then underwent a fourth procedure involving a microdiscectomy at L5-S1. Because that surgery did not alleviate applicant’s symptoms. He then underwent a fusion from L4 through S1.”
The AME in this case opined that the applicant lost 60% of his lumbar spinal function based on how his ADLs and work activities were affected by his industrial injuries. The AME concluded that the DRE and ROM methods did not accurately reflect the applicant’s loss of ADL and work functions. The dissenting opinion objected to use of Figure 15-19 when the physician refers to loss of work functions in his opinion since the AMA Guides in Chapter 1 indicate that the Guides are not to be used for work disability but only for how an impairment affects ADL functioning.
In this case, the AME explained the rationale for his opinion that Figure 15-19 presented a more accurate rating than any other method in the AMA Guides.
In contrast, a WCAB panel rejected use of Figure 15-19 in Graham vs. Pepsi Bottling Co., 2011 Cal. Wrk. Comp. P.D. LEXIS 368, in which the applicant injured his lumbar spine while working as a vending machine installer/delivery driver. His diagnosis was lumbar strain with verified S1 radiculopathy but no surgery. His back pain significantly affected his ADL functioning and he was dependent on pain medications. A PQME concluded, erroneously, that the applicant has a DRE Category II rating of 7% WPI using Table 15-3. In reality, due to the verified radiculopathy, the PQME should have assigned a strict rating as a DRE Category III 10-13% WPI instead.
The PQME then changed his mind and assigned three or four alternative ratings using an Almaraz-Guzman II analysis, including the fact that “Figure 15-19 should be considered.” The WCAB adopted the WCJ’s determination that the hernia table, Table 6-9, 15% WPI, was the most accurate rating method in this case. The WCJ and WCAB panel found that the PQME failed to adequately explain why he rejected the strict WPI rating of DRE II in the first place. In rejecting use of Figure 15-19 in this case, the WCAB and WCJ wrote:
“In the [Laury] case, the AME wrote a thorough analysis of why he applied Figure 15-19 to that applicant’s lumbar spine rating. That applicant did have 60% loss of use of his entire spine after multiple surgeries and fusions (rather than 50% loss of ability to lift and questionably push and pull) resulting from the lumbar strain in this case.”
COMMENTARY
Figure 15-19 can be used in an appropriate case as long as the physician understands the language from page 9 referencing the loss of function of a region and the footnote under Figure 15-19 that allows conversion of a regional impairment to a maximum WPI rating.
There has to be significant permanent objective medical findings to justify use of this method. Whether or not you consider use of Figure 15-19 a strict use of the AMA Guides is irrelevant. If the use of Figure 15-19 is supported by permanent objective medical findings and the physician indicates why that method is the most accurate impairment rating based on the effects of the industrial injuries on the applicant’s ADL functioning, then use of this method would constitute substantial evidence in a given case. As part of his or her explanation of using Figure 15-19, the physician may want to point out that many ADL functions listed on Table 1-2 on page 4 of the AMA Guides overlap with work functions, such as writing, typing, standing, sitting, walking, climbing stairs, grasping, lifting and driving.
One can argue that use of Figure 15-19 is a strict rating in a case such as Laury but is not appropriate in a case such as Graham where the physician in Graham did not properly conclude a strict DRE rating in the first place – which neither the applicant’s attorney nor the defense attorney realized at all. The Graham case is a good example of when not to use Figure 15-19, and the Laury case is a good example of when Figure 15-19 is the most accurate method of obtaining a WPI rating.
© Copyright 2012 Robert G. Rassp, Esq. All rights reserved. Reprinted with permission.
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