Title: Corgatelli v. Steel West, Inc.

State: idaho

Issuer: Idaho Supreme Court (civil)

Document:

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IN THE SUPREME COURT OF THE STATE OF IDAHO 
Docket No. 41012 
 
 
GARY R. CORGATELLI, 
 
       Claimant-Appellant-Cross Respondent, 
 
v. 
 
STEEL WEST, INC., Employer, and 
IDAHO STATE INSURANCE FUND, 
Surety, 
 
       Defendants-Respondents-Cross 
       Respondents, 
 
and 
 
STATE OF IDAHO, INDUSTRIAL 
SPECIAL INDEMNITY FUND, 
 
       Defendant-Respondent-Cross  
       Appellant.  
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Twin Falls, June 2014 Term 
 
2014 Opinion No. 91 
 
Filed:  August 25, 2014 
 
Stephen W. Kenyon, Clerk 
 
       
________________________________________ 
 
 
Appeal from the Industrial Commission of the State of Idaho. 
 
 
The Commission’s award of credit to Steel West for benefits paid is vacated.  
The Commission’s find of liability against ISIF is reversed.  This case is 
remanded for further proceedings consistent with this Opinion. Costs on appeal  
are awarded to Claimant against Steel West and to ISIF against Steel West for its cross-
appeal. 
 
 
Fred J. Lewis, Pocatello, attorney for appellant. 
 
 
Jay Meyers, Pocatello, attorney for respondent Steel West, Inc. 
 
 
Paul B. Rippel, Idaho Falls, attorney for respondent Industrial Special Indemnity Fund. 
________________________ 
 
WALTERS, J., pro tem 
Gary R. Corgatelli sought worker’s compensation benefits from his employer Steel West 
and the State of Idaho’s Industrial Special Indemnity Fund (ISIF) for a 2005 back injury that he 
incurred as a result of his employment. The Idaho Industrial Commission (the Commission) 
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concluded that Corgatelli had a permanent physical impairment of 15% of the whole person, 
attributing 5% to an earlier injury in 1994 and 10% to the 2005 injury, and that Corgatelli was 
totally and permanently disabled. The Commission further concluded that ISIF was liable for 
disability benefits because the effects of Corgatelli’s preexisting impairment from the 1994 
injury combined with his 2005 injury to cause total and permanent disability. The Commission 
subsequently issued an order to clarify that Steel West was entitled to credit on the disability 
award for permanent physical impairment benefits Steel West previously paid to Corgatelli for 
his 2005 injury. Corgatelli appeals the Commission’s order to credit Steel West. ISIF cross-
appeals the Commission’s determination of ISIF liability. As will be explained, we vacate in part 
the credit allowed to Steel West for payments made to Corgatelli as permanent impairment 
benefits, and we reverse the Commission’s determination of ISIF liability. 
I.  FACTUAL AND PROCEDURAL BACKGROUND 
Corgatelli was born in 1947. In 1973, he began employment with Steel West as a fitter 
and welder. In the 1980s, Steel West promoted Corgatelli several times, and he eventually held 
the position of shipping and receiving and paint foreman. In this position, Corgatelli supervised 
the receiving, unloading, sandblasting, and painting of all steel, and he also drove delivery 
trucks. 
On October 4, 1994, Corgatelli’s first work-related injury occurred while pushing a load 
of steel off a delivery truck. He complained of low back and left buttock pain from the injury. 
Corgatelli filed a worker’s compensation complaint on October 11, 1994. Gail Fields, D.O., 
examined Corgatelli, and Dr. Fields awarded Corgatelli a permanent physical impairment of 5% 
of the whole person. Kevin Hill, M.D., also examined Corgatelli, but Dr. Hill awarded Corgatelli 
no impairment rating for the injury. Steel West and Corgatelli executed a lump sum settlement 
agreement wherein Steel West agreed to pay Corgatelli $27,500 for the worker’s compensation 
claim.  
After the injury, Corgatelli was unable to return to the foreman position because he could 
not tolerate the bending, stooping, and lifting required for the position. He accepted a new 
position at Steel West as safety director, where he did mostly paperwork, inventory, and limited 
computer work. He drove delivery trucks and delivered steel within a 35-pound lifting 
restriction.  
On January 3, 2005, Corgatelli’s second work-related injury occurred while stepping 
down from a semi-truck. He experienced immediate back and leg pain. On May 4, 2005, Clark 
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Allen, M.D., performed a decompressive laminotomy, facetectomy, and excision of herniated 
disc at L4-5. After the surgery, Corgatelli continued to work at Steel West as a safety director. In 
August of 2008, Corgatelli experienced increased back and leg pain after making a delivery in 
Wyoming. After other various treatments, Corgatelli had a posterior lumbar interbody fusion 
from L2 to L5 on April 6, 2009. Despite the surgery, Corgatelli had continued to have back and 
leg pain.  
On July 15, 2009, Corgatelli filed a worker’s compensation claim with the Commission 
against Steel West, alleging that he suffered a low back injury while stepping off the semi-truck 
on January 3, 2005. He sought total and permanent disability benefits. On August 4, 2010, David 
Simon, M.D., diagnosed Corgatelli with failed back syndrome. Dr. Simon awarded Corgatelli a 
permanent physical impairment of 15% of the whole person, apportioning 5% to the 1994 injury 
and 10% to the 2005 injury. Dr. Simon also concluded that Corgatelli’s condition was medically 
stationary on August 4, 2010. On January 26, 2011, Corgatelli filed a worker’s compensation 
complaint against the ISIF.  
A Commission referee held a hearing and submitted his recommendation to the 
Commission. The Commission chose not to adopt the referee’s recommendation. The 
Commission concluded that (1) Corgatelli had a permanent physical impairment of 15% of the 
whole person, attributing 5% to the 1994 injury and 10% to the 2005 injury; (2) Corgatelli was 
totally and permanently disabled; and (3) ISIF was liable for a portion of Corgatelli’s total and 
permanent disability benefits because the effects of his preexisting impairment from the 1994 
injury combined with the effects of his 2005 injury to cause total and permanent disability. Using 
the formula from the Court in Carey v. Clearwater County Road Department, 107 Idaho 109, 
686 P.2d 54 (1984), the Commission calculated that Steel West was liable for 66.7% of 
Corgatelli’s benefits for the total and permanent disability, totaling 333.5 weeks of benefits or 
$99,599.78. ISIF was liable for payment of total and permanent disability benefits 333.5 weeks 
after August 4, 2010, the date Corgatelli was medically stationary. The Commission denied Steel 
West’s request to offset its liability by the sum it previously had paid for Corgatelli’s 1994 
injury. 
On August 14, 2012, Steel West filed a motion for reconsideration and clarification. Steel 
West conceded that it did not challenge the Commission’s refusal to offset Steel West’s liability 
by the sum it had paid for Corgatelli’s 1994 injury. Instead, Steel West sought to offset its 
liability by the sum it previously paid for Corgatelli’s 2005 injury. Corgatelli objected to Steel 
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West’s motion. On April 5, 2013, the Commission issued an order to clarify and held that Steel 
West was entitled to credit the total and permanent disability award with the permanent physical 
impairment benefits it already paid for Corgatelli’s 2005 injury.   
Corgatelli appeals the Commission’s order to clarify. ISIF cross-appeals the 
Commission’s finding of ISIF liability.   
II.  ISSUES ON APPEAL 
1. 
Whether certain permanent physical impairment benefits previously paid to Corgatelli for 
his 2005 injury are credited towards Steel West’s liability for total and permanent 
disability benefits. 
2. 
Whether there is substantial and competent evidence to find that the effects of 
Corgatelli’s preexisting impairment from an earlier injury combined with the effects of 
his current injury to cause total and permanent disability. 
III.  STANDARD OF REVIEW 
“When this Court reviews a decision from the Industrial Commission, it exercises free 
review over questions of law but reviews questions of fact only to determine whether substantial 
and competent evidence supports the Commission’s findings.” Vawter v. United Parcel Serv., 
Inc., 155 Idaho 903, 906–07, 318 P.3d 893, 896–97 (2014). “Substantial evidence is more than a 
scintilla of proof, but less than a preponderance.” Zapata v. J.R. Simplot Co., 132 Idaho 513, 
515, 975 P.2d 1178, 1180 (1999). “Substantial and competent evidence is ‘relevant evidence 
which a reasonable mind might accept to support a conclusion.’ The Commission’s conclusions 
on the credibility and weight of evidence will not be disturbed unless the conclusions are clearly 
erroneous.” Vawter, 155 Idaho at 907, 381 P.3d at 897 (quoting Boise Orthopedic Clinic v. Idaho 
State Ins. Fund, 128 Idaho 161, 164, 911 P.2d 754, 757 (1996)). All facts and inferences are 
viewed in the light most favorable to the party who prevailed before the Commission. Zapata, 
132 Idaho at 515, 975 P.2d at 1180.  
The Court exercises free review over issues of statutory interpretation. Sanders v. Bd. of 
Trs. of Mountain Home Sch. Dist. No. 193, 156 Idaho 269, 272, 322 P.3d 1002, 1005 (2014). 
IV.  ANALYSIS 
A. 
The Commission Erred When It Allowed Steel West To Offset Its Liability For 
Total and Permanent Disability Benefits With Permanent Physical Impairment 
Benefits Previously Paid To Corgatelli. 
This Court initially notes that our review of this issue is a narrow one because Corgatelli 
concedes in his briefing that Steel West is entitled to some of the credit awarded by the 
Commission. At the outset of Corgatelli’s brief, he concedes that the Commission properly 
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credited Steel West $10,452.75 of the total credit award of $22,298.75. This conceded sum is 
attributed to an overpayment of $7,466.25 in benefits for a 5% permanent physical impairment 
for sexual dysfunction from 2006 to 2007 and to a payment of $2,986.50 in 2010 for an 
additional 2% permanent physical impairment for the 2005 back injury. Corgatelli contests the 
remaining sum of $11,964. This contested sum represents the amount paid by Steel West to 
Corgatelli from February of 2006 to April of 2007 for his 8% permanent physical impairment 
due to his 2005 back injury. With Corgatelli conceding a portion of the credit award, the only 
issue on appeal is whether the Commission properly concluded that Steel West was entitled to a 
credit of $11,964 for the permanent physical impairment benefits paid to Corgatelli from 2006 to 
2007 for his 2005 back injury. 
1. 
There is no statutory basis in worker’s compensation law to credit the employer 
for permanent physical impairment benefits paid to the employee before the 
award of total and permanent disability benefits. 
Title 72 of the Idaho Code governs worker’s compensation law. I.C. § 72-101. 
In worker’s compensation cases, the claimant’s recovery is typically categorized 
into types of benefits, such as medical expenses, temporary disability, permanent 
impairment, and permanent disability (disability in excess of impairment). 
Because those benefits are determined separately, the claimant’s recovery for 
each type of benefit is an identifiable sum of money. 
 
Seiniger Law Offices, P.A. v. State of Idaho ex rel. Indus. Comm’n, 154 Idaho 461, 466, 299 P.3d 
773, 778 (2013).  
One type of benefit provides compensation to an employee for a permanent impairment. 
“‘Permanent impairment’ is any anatomic or functional abnormality or loss after maximal 
medical rehabilitation has been achieved and which abnormality or loss, medically, is considered 
stable or nonprogressive at the time of evaluation.” I.C. § 72-422. The employee receives a 
rating for the permanent impairment set in terms of a percentage of the whole man, and then the 
employee’s compensation is calculated pursuant to the statutory guidelines. I.C. §§ 72-424, -426 
to -429. These benefits are paid at a percentage of the state average weekly wage. I.C. §§ 72-428 
to -429 
 
Another type of benefit compensates the employee for a permanent disability. Permanent 
disability results “when the actual or presumed ability to engage in gainful activity is reduced or 
absent because of permanent impairment and no fundamental or marked change in the future can 
be reasonably expected.” I.C. § 72-423. “Income benefits for total and partial disability during 
the period of recovery, and thereafter in cases of total and permanent disability, shall be paid to 
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the disabled employee subject to deduction on account of waiting period and subject to the 
maximum and minimum limits set forth in section 72-409, Idaho Code.” I.C. § 72-408. Other 
than a deduction for the “waiting period” provided in Idaho Code section 72-408, Idaho Code 
section 72-406(2) provides another deduction:  
Any income benefits previously paid an injured workman for permanent disability 
to any member or part of his body shall be deducted from the amount of income 
benefits provided for the permanent disability to the same member or part of his 
body caused by a change in his physical condition or by a subsequent injury or 
occupational disease. 
 
I.C. § 72-406(2). In short, pursuant to Idaho Code section 72-406(2), the employer may deduct 
previously paid permanent disability benefits from an additional award of permanent disability 
benefits to the same body part. The income benefits for permanent disability are calculated by 
considering the employee’s average weekly wage. I.C. § 72-408(1); Phinney v. Shoshone Med. 
Ctr., 131 Idaho 529, 533, 960 P.2d 1258, 1262 (1998). 
 Idaho Code section 72-425 dictates the evaluation of permanent disability. It provides: 
“‘Evaluation (rating) of permanent disability’ is an appraisal of the injured employee’s present 
and probable future ability to engage in gainful activity as it is affected by the medical factor of 
permanent impairment and by pertinent nonmedical factors [as] provided in section 72-430, 
Idaho Code.” I.C. § 72-425 (alteration in original). The nonmedical facts provided in Idaho Code 
section 72-430 are:  
[1] the nature of the physical disablement, [2] the disfigurement if of a kind likely 
to limit the employee in procuring or holding employment, [3] the cumulative 
effect of multiple injuries, [4] the occupation of the employee, [5] and his age at 
the time of accident causing the injury, or manifestation of the occupational 
disease, consideration being given to the diminished ability of the afflicted 
employee to compete in an open labor market within a reasonable geographical 
area considering all the personal and economic circumstances of the employee, 
and [6] other factors as the commission may deem relevant . . . . 
 
I.C. § 72-430(1). Permanent disability may be total or partial. “Total and permanent disability 
may be proven either by showing that the claimant’s permanent impairment together with 
nonmedical factors totals 100% or by showing that the claimant fits within the definition of an 
odd-lot worker.” Christensen v. S.L. Start & Assocs., Inc., 147 Idaho 289, 292, 207 P.3d 1020, 
1023 (2009). 
 
The Commission relied on Idaho Code section 72-425 to conclude that Steel West was 
entitled to a credit for permanent physical impairment benefits previously paid to Corgatelli. As 
discussed above, that statute regulates the evaluation of permanent disability. I.C. § 72-425. The 
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statute is silent, however, with respect to any matter regarding the calculation of income benefits, 
let alone a benefit credit or deduction. Therefore, this Court concludes that the Commission 
erroneously relied on Idaho Code section 72-425 to provide Steel West a credit for income 
benefits because Idaho Code section 72-425 relates to the evaluation of the employee’s 
permanent disability and not the computation of benefits. 
Examining worker’s compensation law as a whole, Roe v. Albertson’s Inc., 141 Idaho 
524, 528, 112 P.3d 812, 816 (2005), this Court finds that there is no statutory basis for the 
Commission to award Steel West a credit for permanent physical impairment benefits previously 
paid to Corgatelli. Idaho Code section 72-408, which awards the employee income benefits for 
permanent disability, only offers a deduction “on account of waiting period.” The current version 
of the statute provides for no other deductions. Notably, an earlier version of Idaho Code section 
72-408, then-codified at Idaho Code section 72-310(a), allowed for a deduction for “partial 
disability” along with the waiting period deduction. I.C. § 72-130(a) (1969); see also Endicott v. 
Potlach Forests, 69 Idaho 450, 452, 208 P.2d 803, 804 (1949). However, this statute was 
repealed in 1971 when the Legislature recodified Idaho’s worker’s compensation law. Ch. 124, § 
1, 1971 Idaho Sess. Laws 422, 424. Thus, the current version of Idaho Code section 72-408, 
which provides for the employee such as Corgatelli to receive total and permanent disability 
benefits, includes no deduction or credit for previously paid permanent impairment benefits in its 
award of disability benefits. 
The other relevant statute for the award of disability benefits, Idaho Code section 72-
406(2), allows for a deduction of previously paid “permanent disability” benefits for an injury to 
any member or part of the claimant’s body from a new award of permanent disability benefits, 
but only if the new benefits are provided “to the same member or part of his body caused by a 
change in his physical condition or by a subsequent injury or occupational disease.” I.C. § 72-
406(2). Although partial permanent disability benefits are calculated in relation to permanent 
physical impairment benefits, Idaho Code sections 72-427 to -429, partial permanent disability 
benefits and permanent physical impairment benefits are two separate forms of compensation. In 
this case, Corgatelli challenges Steel West’s credit for permanent physical impairment benefits 
paid for the 2005 injury before any finding or award of a subsequent permanent disability. 
Therefore, Idaho Code section 72-406(2) offers no statutory basis for Steel West to receive a 
credit for previously paid permanent physical impairment benefits. 
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No other statute in Idaho’s worker’s compensation law permits the employer to receive 
credit for permanent physical impairment benefits paid before the award of total and permanent 
disability benefits. As a purely statutory scheme, the Court cannot judicially construct a credit for 
employers into worker’s compensation law. Our decision is consistent with other jurisdictions 
that have considered similar issues and interpreted their workers’ compensation statutes. Taylor 
v. State Accident Ins. Fund, 595 P.2d 515, 517–18 (Or. Ct. App. 1979); Durant v. Butler Bros., 
148 N.W.2d 152, 154–57 (Minn. 1976); Orvis v. Hutchins, 179 A.2d 470, 472–74 (Vt. 1962); 
Nicely v. Virginia Elec. & Power Co., 80 S.E.2d 529, 531–33 (Va. 1954); see also 5 Arthur 
Larson & Lex K. Larson, Larson’s Workers’ Compensation Law § 92.02 (rev. ed. 2014); 100 
C.J.S. Workers’ Compensation § 702 (2014). 
 
Based on the above reasons, the Court finds that the Commission erred in awarding Steel 
West a credit of $11,964 for the permanent physical impairment benefits paid to Corgatelli in 
2006 to 2007 for his 2005 back injury. The Court declines to rule on the validity of the other 
credited permanent physical impairment benefits which were conceded by Corgatelli on appeal. 
B. 
There Is Not Substantial And Competent Evidence To Support The Commission’s 
Finding of ISIF Liability.  
ISIF contends that the Commission erred by subjecting it to liability for Corgatelli’s total 
and permanent disability benefits. ISIF liability is governed by Idaho Code section 72-332(1). 
That section provides:  
If an employee who has a permanent physical impairment from any cause or 
origin, incurs a subsequent disability by an injury or occupational disease arising 
out of and in the course of his employment, and by reason of the combined effects 
of both the pre-existing impairment and the subsequent injury or occupational 
disease or by reason of the aggravation and acceleration of the pre-existing 
impairment suffers total and permanent disability, the employer and surety shall 
be liable for payment of compensation benefits only for the disability caused by 
the injury or occupational disease, including scheduled and unscheduled 
permanent disabilities, and the injured employee shall be compensated for the 
remainder of his income benefits out of the industrial special indemnity account. 
 
I.C. § 72-332(1). “Under § 72-332(1), a party attempting to prove ISIF liability must show: (1) 
‘there was a pre-existing impairment’; (2) ‘the impairment was manifest’; (3) ‘the impairment 
was a subjective hindrance’; and (4) ‘the pre-existing impairment and the subsequent injury in 
some way combine to result in total permanent disability.’” Vawter v. United Parcel Serv., Inc., 
155 Idaho 903, 910, 318 P.3d 893, 900 (2014) (quoting Bybee v. State, Indus. Special Indem. 
Fund, 129 Idaho 76, 80, 921 P.2d 1200, 1204 (1996)). In other words, the party “seeking to 
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invoke the liability of ISIF” has the burden of proof to meet the requirements under Idaho Code 
section 72-332(1). See Garcia v. J.R. Simplot Co., 115 Idaho 966, 970, 772 P.2d 173, 177 
(1989), overruled on other grounds, Archer v. Bonners Ferry Datsun, 117 Idaho 166, 169, 786 
P.2d 557, 560 (1990).  
 
In this case, ISIF challenges the Commission’s factual findings and legal analysis on the 
fourth requirement only: whether Corgatelli’s preexisting impairment and subsequent injury in 
some way combined to result in total and permanent disability. To satisfy the fourth requirement 
in Idaho Code section 72-332(1), “the ‘but for’ standard is the appropriate test to determine 
whether the total permanent disability is the result of the combined effects of the pre-existing 
condition and the work-related injury.” Garcia, 115 Idaho at 970, 772 P.2d at 177. The Court has 
reiterated the “but for” standard in subsequent cases and it is the controlling test for the 
“combining effects” requirement. Eckhart v. State, Indus. Special Indem. Fund, 133 Idaho 260, 
264, 985 P.2d 685, 689 (1999); Bybee, 129 Idaho at 81, 921 P.2d at 1205; Selzler v. State, Indus. 
Special Indem. Fund, 124 Idaho 144, 146, 857 P.2d 623, 625 (1993). The “but for” test requires a 
showing by the party invoking liability that the claimant would not have been totally and 
permanently disabled but for the preexisting impairment. Garcia, 115 Idaho at 970, 772 P.2d at 
177. 
1. 
Substantial and competent evidence does not show that the effects of Corgatelli’s 
preexisting impairment and subsequent injury in some way combined to result in 
total and permanent disability. 
 
 
Corgatelli’s first accident occurred on October 4, 1994. On October 20, 1994, Dr. Fields 
examined Corgatelli. After a “normal MRI” reading by radiologist Allen Eng, M.D., Dr. Fields 
ordered a bone scan. The study of the bone scan read “markedly increased radiotracer uptake . . . 
at L3-4” and “mild impaction of superior vertebral endplate of L4 laterally to the left either due 
to a longstanding Schmorl’s node or a recent mild impaction.” The scan found no evidence of 
spondylolysis or metastatic disease.  
 
On or about March 3, 1995, neurosurgeon Peter Schossberger, M.D., saw Corgatelli for a 
second opinion. Dr. Schossberger disagreed with Dr. Eng’s reading of the MRI as normal. Dr. 
Schossberger read the MRI as showing a “considerably different reading from the official 
reading of normal with normal vertebrae body signal for pulse sequences used, normal nuclear 
signal, etc.” To Dr. Schossberger, the MRI showed (1) “nuclear dehydration at L1-2, L2-3, L3-4, 
and L4-5;” (2) “evident left posterior superior L4 body Schmorl’s node or end plate fracture . . . 
with increased water signal in the bone marrow of the surrounding L4 body . . . and also some 
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increased water signal in the posterior inferior L3 body;” (3) “may be some focal tiny left L3-4 
disc herniation;” (4) “slight diffuse central L4-5 annulus convexity without definite disc 
herniation;” and (5) “normal L5-Sl nuclear hydration, annulus, and canal.” Dr. Schossberger 
concluded his evaluation of Corgatelli by stating: “nuclear dehydration at four lumbar levels, 
multilevel osteophytes, and superior L4 end plate and surrounding bone changes including 
focally positive bone scan at about left L3-4 are more likely that not degenerative cause and/or a 
result of cumulative life work lifting activities.” Dr. Schossberger referred Corgatelli to Dr. Hill.  
 
On August 17, 1995, Dr. Hill examined Corgatelli. He stated Corgatelli’s condition as (1) 
“Chronic mechanical low back pain sub acute secondary to musculoligamentous injury” and (2) 
“Degenerative disc and joint disease L1-5. Left facet arthritis L3-4.” Dr. Hill also stated that 
Corgatelli has “significate [sic] degenerative disc and lumbar spine disease.”   
Due to this injury, Dr. Fields permanently restricted Corgatelli to lifting no more than 35 
pounds and recommended that he limit his bending and stooping. He gave Corgatelli a 5% of the 
whole person impairment rating. Dr. Hill restricted Corgatelli to lifting 50 pounds occasionally, 
20 pounds frequently, and 10 pounds constantly and recommended that he limit climbing, sitting, 
kneeling, squatting, and crawling and avoid bending and stooping at all times. He did not award 
Corgatelli an impairment rating. Because Corgatelli could not tolerate the bending, stooping, and 
lifting required for his pre-injury position, he took a $3.00 per hour pay cut and began a new 
position at Steel West that allowed him to limit those activities and lift no more than 35 pounds.  
 
Corgatelli’s second accident occurred on January 3, 2005. Corgatelli returned to Dr. 
Fields on January 25, 2005. Dr. Fields proposed that Corgatelli was suffering from “degenerative 
disc disease with lumbar sacral strain or sprain with left sciatica neuralgia symptoms or 
radiculopathy.” Dr. Fields ordered an MRI of Corgatelli’s lumbar spine. D.J. Marc Cardinal, 
M.D., read the MRI as: (1) “canal and foramina are developmentally below average in size;” (2) 
“L4-5 demonstrates a small disc extrusion laterally at the lateral margin of the left intervertebral 
foramen severely narrowing the left intervertebral foramen and displacing the left L4 nerve root. 
Degenerative changes are present mildly narrowing the thecal sac and moderately narrowing the 
right intervertebral foramen; (3) “At L3-4 degenerative changes are present moderately 
narrowing the foramina and mildly narrowing the thecal sac; (4) “At L2-3 degenerative changes 
are present moderately narrowing the right intervertebral foramen and causing mild narrowing of 
the thecal sac and left intervertebral foramen;” and (5) “At L1-2 degenerative changes are 
present mildly narrowing the canal and foramina.” “Reviewing the report, Dr. Fields commented 
11 
that it demonstrated the presence of degenerative disc disease at all levels” and a herniated disc 
at L4-5. Dr. Fields referred Corgatelli to Dr. Allen.  
 
Dr. Huneycutt first examined Corgatelli on March 1, 2005. On May 4, 2005, Dr. Allen 
performed a decompressive laminotomy, facetectomy, and excision of herniated disc at L4-5 on 
Corgatelli. Dr. Allen noted in his operative report that the indications for the surgery were “a far 
lateral herniated disc and evidence of severe neuroforaminal compression at L4-5 on the left.” 
He also noted that Corgatelli had “significant degenerative changes in his back.”   
 
On September 17, 2008, Corgatelli returned to Dr. Allen with back pain, and Dr. Allen 
ordered an MRI. The MRI study read: (1) “changes of previous left hemilaminectomy at L4-5;” 
(2) “Multilevel disc bulging with mild central spinal canal stenosis at L3-4 related to the disc 
bulge, facet joint degenerative changes, and mild prominence in epidural fat;” and (3) “Scattered 
areas of bilateral neuroforaminal narrowing, most severe on the left at L4-5 where there is near 
complete effacement of the face surrounding the exiting L4 nerve root. Correlation with pain in 
the left L4 nerve root distribution is recommended.” Following the MRI, Dr. Huneycutt 
diagnosed Corgatelli with tight foraminal stenosis at L4-5 on the left and degenerative changes 
throughout the lumbar spine. On October 29, 2008, Dr. Huneycutt responded to an inquiry by 
ISIF about Corgatelli’s return for treatment for back pain, and he stated that Corgatelli’s current 
symptoms were related to his 2005 bank injury and there was no evidence of a new injury. He 
agreed with ISIF’s statement that Corgatelli was “experiencing pain due to a natural progression 
of his underlying disc disease,” and he explained that Corgatelli “is suffering from a progression 
from his 2005 back injury. . . . evidenced by his report of a return of symptoms and his imaging 
studies that by comparison reveal a continued decline and failure of his injured disk.”  
On December 10, 2008, Dr. Simon examined Corgatelli for ISIF and prepared a report 
(hereinafter 2008 report). He acknowledged Corgatelli’s diagnosis from Dr. Hill for the 1994 
back injury. Dr. Simon diagnosed Corgatelli with “Left l4 radiculopathy secondary to foraminal 
stenosis. This radiculopathy as a result of his previous low back injury and the subsequent 
surgery” and “Status-post L4-5 discectomy on 5/4/05 following a work injury on 1/3/05.” He 
opined that his current low back problems and the 2005 injury had a causal relationship.  
After Corgatelli received injection therapy from Dr. Huneycutt, Dr. Allen performed a 
posterior lumbar interbody fusion from L2 to L5 on April 6, 2009. In a pre-operative 
examination, Dr. Allen diagnosed Corgatelli with severe disc collapse at L2-3, L3-4, and L4-5 
with modic changes mostly at L2-3 and severe neuroforaminal stenosis at all levels. In Dr. 
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Allen’s operative report, he stated that the indications for the surgery were severe disc collapse 
with herniated disc at L2-3, L3-4, and L4-5, and significant far lateral stenosis. Dr. Allen 
eventually diagnosed Corgatelli with failed back syndrome.  
On August 4, 2010, Dr. Simon again examined Corgatelli for ISIF and prepared a report 
(hereinafter 2010 report). He too diagnosed Corgatelli with failed back syndrome. He opined that 
there was a causal relationship between Corgatelli’s current back problems and the 2005 injury. 
He also acknowledged that Corgatelli had a back injury from 1994 and that Corgatelli was 
diagnosed by Dr. Hill for that injury. He did not, however, attribute any of Corgatelli’s 
limitations and restrictions to his 1994 injury. Rather, he stated that Corgatelli’s physical work 
restrictions from an August, 28, 2009, Functional Capacity Evaluation (FCE) “are permanent and 
they would be related to the [2005] industrial injury.”   
From the record provided to the Court, it appears that Dr. Simon was the only physician 
deposed. He testified that he reviewed Dr. Allen’s operative report in preparing his 2010 report, 
and he then was asked, “To what extent would [Dr. Allen’s] fusion address anatomic findings 
that pre-existed the 2005 accident?” Dr. Simon answered:  
Well, the 2005 accident injury affected the L4-5 level and the previous stuff that 
we talked about back in 1995. The worse level was at the L3-4 level. I’m not a 
surgeon. I’m not sure why he went up to the L2, but that being closer to the L3-4 
level. I mean, that level would also be -- you know, that would more likely be 
related to the pre-existing problems and the problems at the L3-4 level than the 
work related at the L4-5 level. 
 
Regarding his 2008 report, Dr. Simon was asked “how much” of the back pain reported by 
Corgatelli in 2008 was an “aggravation of the 2005 anatomy versus new injury type.” He 
explained that “his thought process” was that Corgatelli’s “most significant problem” was at the 
L4-5 level where he had the herniated disc from the 2005 injury, and therefore his 2008 back 
pain was related to the 2005 injury. If Corgatelli had complained in 2008 with “the most 
problems” at the L3-4 level, Dr. Simon explained, his opinion would have been that L3-4 “was 
the worst area in 1995; this is more likely pre-existing and not related to the 2005 injury.”   
 
Due to the aggravation and progression of the 2005 injury, Corgatelli’s activities were 
further restricted. The FCE placed Corgatelli “at a sedentary demand capacity.” The FCE 
observed that Corgatelli could lift up to 20 pounds occasionally and tolerated sitting for no more 
than 10 minutes. The FCE also noted that Corgatelli was unable to complete hand coordination 
tasks. Dr. Simon agreed that Corgatelli’s restrictions observed in the FCE were appropriate and 
13 
permanent. He stated that Corgatelli would never return to his pre-injury status and, as a result of 
his fusion and ongoing symptoms, Corgatelli would need continued follow-up treatment.  
 
Two vocational rehabilitation experts examined Corgatelli. Mary Barros-Bailey, Ph.D., 
reviewed the records from Corgatelli’s 1994 and 2005 injuries and the restrictions imposed due 
to those injuries. Dr. Barros-Bailey determined that Corgatelli would not qualify for any work 
within his restrictions. She noted that Corgatelli had significant functional restrictions from the 
1994 injury that resulted in his job change and reduced pay. She attributed 27% of his total 
disability to the restrictions from the 1994 injury, stating that those restrictions “impacted his 
wage earning capacity and flexibility within the labor market based on loss of access to jobs he 
could previously attain.” Nancy Collins, Ph.D., reached similar conclusions. Dr. Collins 
discussed Corgatelli’s diagnoses and restrictions from both injuries. She could not think of any 
job regularly available in the labor market for Corgatelli due to his physical restrictions and lack 
of skills, and she determined that he was totally disabled. Similar to Dr. Barros-Bailey, Dr. 
Collins noted that Corgatelli’s 1994 injury was “manifest and a hindrance.” Dr. Collins 
explained that Steel West “was able to accommodate his initial restrictions, but even after 36 
years of work . . . they were unable to accommodate the most recent restrictions.” She stated, 
“The combination of his pre-existing restrictions and his most recent restrictions leave him so 
injured he is not regularly employable in any well[-]known branch of the labor market.”  
 
Based on this evidence, the Commission concluded that the combined effects of 
Corgatelli’s preexisting impairment from the 1994 injury and the 2005 injury resulted in total 
and permanent disability. The Commission found it “clear” that Corgatelli’s 2009 L2-5 fusion by 
Dr. Allen was undertaken because of the L4-5 lesion related to the 2005 injury “and the 
multilevel degenerative changes” in Corgatelli’s spine “first noted in 1994, and progressing 
thereafter.” It appears that the Commission relied on three pieces of evidence for this conclusion: 
(1) the 2005 MRI ordered by Dr. Fields demonstrated severe degenerative changes at levels 
above and below L4-5; (2) Dr. Allen’s “operative report clearly reflects that the indications for 
the surgery are multifactorial, and not solely related to the need to address the L4-5 level;” and 
(3) Dr. Simon’s testimony that “the 2005 accident injury affected the L4-5 level and the previous 
stuff that we talked about back in 1995” and that it was “more likely” Dr. Allen “went up to the 
L2” due to the 1994 injury. Therefore, according to the Commission, “[b]ecause [Corgatelli’s] 
surgery was necessitated by both the subject accident and his preexisting condition, and because 
14 
[he] had a poor surgical outcome, such that he is currently totally and permanently disabled, it is 
clear that the combining with element of the prima facie case has been met.” 
 
Our review of the Commission’s decision reveals that the Commission failed to use the 
“but for” test to determine whether Steel West satisfied the “combined effects” requirement in 
Idaho Code section 72-332(1). Instead of the “but for” test, Commission examined whether 
Corgatelli’s preexisting impairment from his 1994 injury and his 2005 injury together 
“necessitated” the 2009 L2-5 fusion. By inferring that Corgatelli would not have needed the 
2009 fusion from L2 to L5 had he not suffered his 1994 injury, the Commission erroneously 
reasoned that Corgatelli’s total and permanent disability after the fusion was the result of the 
combined effects of his two injuries. Put another way, the Commission erred by determining that 
Corgatelli was totally and permanently disabled due to the combined effects of the two injuries 
solely because the combined effects of the two injuries may have influenced the scope of the 
unsuccessful fusion. However, the inquiry is not whether the combined effects of the claimant’s 
preexisting impairment and current injury required a certain medical procedure that later 
contributed to total and permanent disability; the inquiry is whether the combined effects of the 
claimant’s preexisting impairment and current injury resulted in total and permanent disability. 
I.C. § 72-332(1). For this question, the Commission must determine whether the claimant’s 
disability would not have been total but for the preexisting impairment. Bybee v. State, Indus. 
Special Indem. Fund, 129 Idaho 76, 80–81, 921 P.2d 1200, 1204–05 (1996); Garcia v. J.R. 
Simplot Co., 115 Idaho 966, 970, 772 P.2d 173, 177 (1989). As such, the Commission should 
have further determined whether, but for Corgatelli’s preexisting impairment from his 1994 
injury, Corgatelli would not have been permanently and totally disabled from the effects of his 
2005 injury, which includes the fusion. Without this determination, the Commission’s decision is 
erroneous.  
 
Based on the evidence in the record, this Court holds that Steel West failed to satisfy the 
“but for” test. While the evidence shows that Corgatelli had severe degenerative changes at 
levels other than the 2005 injury area, and that the 2005 injury “affected” the 1994 injury area, 
there is a lack of medical evidence to support the determination that, but for Corgatelli’s 
preexisting impairment from the 1994 injury, he would not have been totally and permanently 
disabled due to the effects of his 2005 injury. Not one medical expert opined that a combination 
of Corgatelli’s 1994 preexisting impairment and 2005 injury resulted in total and permanent 
disability. Nor do the various medical documents support a finding that a combination of the two 
15 
injuries resulted in total and permanent disability. The strongest evidence for Steel West’s 
position—the indications in Dr. Allen’s operative report from Corgatelli’s 2009 L2-5 fusion—at 
best supports only an inference that Corgatelli had residual effects from the 1994 injury that 
exacerbated the effects of his 2005 injury pre-surgery, but those indications say nothing about 
the combined effects of the 1994 preexisting impairment and 2005 injury post-surgery to result 
in total and permanent disability. In summary, there is not substantial and competent evidence to 
show that Corgatelli’s disability after the 2005 injury would not have been total but for the 
preexisting impairment from 1994. 
 
Moreover, it was error for the Commission to determine that both the 1994 injury and 
2005 injury necessitated the 2009 L2-5 fusion simply because the surgery addressed more than 
the L4-5 level. The Court has cautioned agencies in their role as fact-finders against substituting 
their own lay understanding of medical information to reach a medical opinion commonly 
reserved to an expert; an agency simply may not use its specialized knowledge as a substitute for 
evidence presented at a hearing. Mazzone v. Texas Roadhouse, Inc., 154 Idaho 750, 761, 302 
P.3d 718, 729 (2013). The Court recognizes that an agency “may, however, utilize its expertise 
in drawing inferences from the facts or record or to resolve conflicts in the evidence.” Id. An 
agency may weigh the evidence provided, but it may not inject its own unqualified medical 
opinion to draw a conclusion from the evidence. In this case, the Commission exceeded its fact-
finding role by relying on its own unsupported medical opinion “that in the absence of multilevel 
problems, surgeons typically prefer to limit fusion procedures to levels where it is absolutely 
necessary . . . .” to conclude that the 2009 L2-5 fusion addressed injuries from the 1994 and 2005 
accident. There is no medical evidence in the record to support the Commission’s medical 
opinion or reach it by inference from other medical evidence. The Commission’s conclusion 
regarding the scope of 2009 L2-5 fusion was an improper use of its specialized knowledge as a 
substitute for the evidence. 
 
In conclusion, the Commission erred in substituting its own medical opinion to make 
findings on the combined effects of Corgatelli’s preexisting impairment and current injury. Due 
to the lack of substantial and competent evidence to support its position, Steel West has not met 
its burden to show that Corgatelli would not have been permanently and totally disabled but for 
his preexisting impairment. 
V.  CONCLUSION 
16 
The Commission’s award to Steel West of a credit for permanent physical impairment 
benefits previously paid to Corgatelli in 2006 and 2007 for his 2005 back injury is vacated. The 
Commission’s finding of ISIF liability is reversed. This case is remanded for further proceedings 
consistent with this opinion. Costs on appeal are awarded to the Claimant, Gary Corgatelli, 
against Steel West and to ISIF against Steel West for its cross-appeal. 
Chief Justice BURDICK, Justices EISMANN, J. JONES and HORTON, CONCUR.