Opinion ID: 1991894
Heading Depth: 1
Heading Rank: 3

Heading: Liability for Pre-Existing Industrial Disability.

Text: Nelson and Basic Materials disagree on the correctness of the commissioner's finding that Nelson suffered only an eighteen percent industrial disability. Although both parties speak in terms of the substantiality of the evidence to support this finding, their real dispute is with the applicable principles of law which govern the commissioner's consideration of this issue. Nelson argues that his shoulder injury in combination with his hearing loss and knee problems make him totally disabled. Basic Materials claims that it cannot be held liable for any industrial disability not directly caused by the injury sustained in the 1988 fall. The industrial commissioner took the approach urged by Basic Materials. We think this was error. An employer's liability for an employee's industrial disability is complicated when that disability results in part from a prior injury or condition. In deciding this case, it is helpful to summarize the various rules that might apply in successive-injury situations. A. The apportionment rule. Iowa applies a rule of apportionment in limited situations. When a prior injury, condition or illness, unrelated to employment, independently produces an ascertainable portion of an injured employee's cumulative industrial disability, the employer is liable only for that portion of the industrial disability attributable to the current injury. Varied Enterprises, Inc. v. Sumner, 353 N.W.2d 407, 411 (Iowa 1984). In other words, the industrial disability is apportioned between that caused by the work-related injury and that caused by the nonwork-related condition or injury. The employer is liable only for the work-related portion. It is important to recognize two limitations on this rule. First, the prior injury or condition must cause an ascertainable portion of the ultimate industrial disability. Id. Thus, if the portion of the industrial disability resulting from the pre-existing, nonwork-related injury or condition cannot be determined, the employer is liable for the full industrial disability of the employee. Tussing v. George A. Hormel & Co., 461 N.W.2d 450, 453 (Iowa 1990); Varied Enterprises, 353 N.W.2d at 411. Second, the prior injury or condition must independently produce some degree of industrial disability before the second injury. Bearce v. FMC Corp., 465 N.W.2d 531, 535 (Iowa 1991); Varied Enterprises, 353 N.W.2d at 411. Hence, the apportionment rule does not apply where the prior condition or injury has not caused any industrial disability. Bearce, 465 N.W.2d at 535, 537. Similarly, the apportionment rule does not apply where the second injury aggravates the pre-existing condition. Id. at 536; Rose v. John Deere Ottumwa Works, 247 Iowa 900, 908, 76 N.W.2d 756, 760-61 (1956). In these situations, the employer is liable for the full industrial disability. B. The full-responsibility rule. Perhaps most importantly, the rule allowing apportionment for prior conditions causing industrial disability does not apply to conditions and injuries related to employment. See Tussing, 461 N.W.2d at 453. When there are two successive work-related injuries, the employer liable for the second injury is generally held liable for the entire disability resulting from the combination of the prior disability and the present injury. Celotex Corp. v. Auten, 541 N.W.2d 252, 254 (Iowa 1995). In another opinion filed today, we applied this full responsibility rule, holding the employer liable for its employee's 100% permanent industrial disability resulting from a recent work-related injury and two prior work-related injuries. Id. Thus, the employer liable for the current injury is also liable for any preexisting industrial disability caused by a work-related injury when that disability combines with industrial disability caused by a later injury. C. Applicability of apportionment and full-responsibility rules here. Any ascertainable portion of Nelson's industrial disability resulting independently from nonwork-related injuries or conditions is subject to apportionment. However, Nelson's 1963 injury was work related. Therefore, to the extent the 1963 injury caused industrial disability prior to Nelson's 1988 fall, the full-responsibility rule applies. Although the industrial commissioner concluded that Nelson was totally disabled from his knee injury, he did not consider whether any of this industrial disability predated Nelson's 1988 fall. This was error. Therefore, we must reverse the district court's decision affirming the industrial commissioner's determination of industrial disability and remand for further proceedings. On remand the industrial commissioner need not separately compute the extent of industrial disability caused by the left knee injury. Rather, any impairment caused by this prior injury as of the date of the shoulder injury will be one of the factors used to measure Nelson's industrial disability. Thus, if Nelson's employability at the time of the 1988 fall was affected by the existence of his prior knee injury, the industrial commissioner must include the impact of that prior injury in the calculation of industrial disability. Any disability resulting from the left knee injury after the occurrence of the shoulder injury shall not be considered. Although our decision on this issue requires a reversal, we proceed to address the other issues raised on appeal since they are likely to recur on remand.