BRIAN A. WARD, Employee/Respondent, v. BANG PRINTING, INC. and SFM MUTUAL INS. CO., Employer-Insurer/Appellants and QUICKSILVER EXPRESS COURIER, INC. and LIBERTY MUT. INS. CO., Employer-Insurer/Respondents and CTR. FOR DIAGNOSTIC IMAGING, Intervenor.

Employer Bang Printing, Inc. appeals the compensation judge’s award of benefits apportioned between the employee’s two work injuries. Appellant asserts that the compensation judge failed to follow uncontroverted medical opinion and lacked substantial evidence in determining that 20 percent of the employee’s need for treatment was properly assigned to Bang Printing and in determining a causal relationship between some of the medical care provided and the employee’s July 17, 1997, work injury. As the compensation judge’s reliance on medical opinion was not an abuse of discretion, and substantial evidence in the record supports the judge’s decision, we affirm.

The employee, Brian Ward, worked for Bang Printing, Inc. (Bang Printing) as a press feeder, positioning paper. The employee’s work activities resulted in an admitted Gillette-type injury^[1] to his low back, with July 17, 1997, assigned as the date of injury. On August 21, 1998, he underwent surgery, which consisted of an artificial disc inserted at L5-S1. The employee reached maximum medical improvement (MMI) for the injury on October 3, 1999. The employee’s low back was rated at 12 percent permanent partial disability.

After a period of adjustment, the employee was pain-free in his low back from 2000 to 2017. The employee worked a number of physical jobs over this period with no complaints of pain from his low back.

In March 2017, the employee was hired as a courier by Quicksilver Express Courier, Inc. (Quicksilver Express). On May 26, 2017, the employee was delivering boxes using a cart when the boxes shifted. The employee tried to prevent the boxes from falling and, in doing so, the employee twisted his back. He experienced immediate pain in his low back and right arm. The employee underwent conservative treatment that did not relieve his low back pain. The employee also complained of right wrist pain that is variously diagnosed as a sprain or carpal tunnel syndrome. The employee was taken off of work due to the injury and has remained off work.

On August 29, 2017, the employee underwent an independent medical examination (IME) conducted by Stephen Barron, M.D., on behalf of Quicksilver Express. Dr. Barron did not have the surgical report from 1998 and he incorrectly identified that surgery as a fusion. Dr. Barron opined that the employee had not experienced a work injury to either his low back or right wrist on May 26, 2017. Dr. Barron attributed all of the employee’s symptoms to preexisting conditions.

On October 19, 2017, the employee underwent an MRI through his medical provider.^[2] The radiologist interpreted the results as showing narrowed nerve root openings that are the cause of the employee’s lumbar pain symptoms. The narrowing was explicitly identified as being at the site of the employee’s disc replacement surgery in 1998. Surgery was recommended to address the employee’s symptoms.

On December 18, 2017, the employee was examined by Dr. McIver, his treating physician. Dr. McIver opined that the employee’s pain was caused by bilateral facet arthropathy at L3-L4 and L4-L5 and right-side meralgia paresthetica. Dr. McIver proposed injections and radiofrequency ablation to address the employee’s lumbar pain, with a referral for pain management. On January 29, 2018, the employee underwent medial branch blocks and obtained no pain relief. On February 9, 2018, the employee underwent a steroid injection and obtained no pain relief. With the lack of success at relieving the employee’s low back pain, Dr. McIver recommended fusion surgery. Dr. McIver described the surgery to the employee as a fusion with hardware, with increased difficulty due to the bone growth and scar tissue from his 1998 surgical procedure.

On June 6, 2018, the employee underwent an IME conducted by Bryan Lynn, M.D., on behalf of Bang Printing. Dr. Lynn made note of the employee’s absence of symptoms and lack of any medical treatment for the low back following the 1998 surgery. Dr. Lynn attributed 100 percent of the responsibility for employee’s symptoms to the May 26, 2017, work injury. Dr. Lynn considered the employee to be a surgical candidate for L5-S1 fusion after exhaustion of physical therapy and cessation of the employee’s smoking.

The employee filed a claim petition seeking approval of the surgery proposed by Dr. McIver. Bang Printing filed a Petition for Discontinuance seeking to terminate temporary total disability benefits. The pleadings were consolidated and the matter came on for hearing before Compensation Judge Stephen Daly on July 11, 2018. The employee was the sole witness. The compensation judge found that the employee suffered work injuries on both July 17, 1997, and May 26, 2017, and both contributed to the employee’s current condition and need for treatment. The judge apportioned to the July 17, 1997, work injury with Bang Printing 20 percent of the responsibility and apportioned the remaining 80 percent to the May 26, 2017, work injury with Quicksilver Express. Bang Printing appealed the decision.

On appeal, the Workers’ Compensation Court of Appeals must determine whether “the findings of fact and order [are] clearly erroneous and unsupported by substantial evidence in view of the entire record as submitted.” Minn. Stat. § 176.421, subd. 1(3). Substantial evidence supports the findings if, in the context of the entire record, “they are supported by evidence that a reasonable mind might accept as adequate.” Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984). Where evidence conflicts or more than one inference may reasonably be drawn from the evidence, the findings are to be affirmed. Id. at 60, 37 W.C.D. at 240. Similarly, findings of fact should not be disturbed, even though the reviewing court might disagree with them, “unless they are clearly erroneous in the sense that they are manifestly contrary to the weight of evidence or not reasonably supported by the evidence as a whole.” Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).

A decision which rests upon the application of a statute or rule to essentially undisputed facts generally involves a question of law which the Workers’ Compensation Court of Appeals may consider de novo. Krovchuk v. Koch Oil Refinery, 48 W.C.D. 607, 608 (W.C.C.A. 1993), summarily aff’d (Minn. June 3, 1993).

At the hearing, Bang Printing objected to the admission of Dr. Barron’s opinion as lacking foundation. The objection was overruled and the opinion was admitted into the record. Dr. Barron characterized the employee’s 1998 surgery as a fusion, when the procedure was a disc replacement. On appeal, Bang Printing contends that fundamental information was not reviewed by Dr. Barron and admission of and reliance on the opinion was error.

Where reliance on medical opinion is at issue, this court follows the standard set by the Minnesota Supreme Court, which is, “The adequacy of foundation for an expert opinion is a decision within the discretion of the trial judge, subject to review for abuse of discretion.”^[3] An expert need not be provided with every possible fact, but must have enough facts to form a reasonable opinion.^[4] Here, Dr. Barron’s mischaracterization of the surgical procedure performed at the L5-S1 level in 1998 does not obviate the existence of severe degenerative disc disease at that level or the accompanying 12 percent permanent partial disability rating assigned to it. There is nothing in the opinion of Dr. Barron to suggest that he is engaging in speculation or conjecture. His opinion meets the foundation standard set out in Gianotti. Admission of Dr. Barron’s report to the record does not constitute an abuse of discretion.^[5]

Bang Printing’s complaints regarding the compensation judge’s use of Dr. Barron’s conclusions are directed to the weight afforded that opinion by the compensation judge. The opinion was weighed by the compensation judge, who did not agree with Dr. Barron’s opinion that liability rested solely with the 1997 injury. Regarding the May 26, 2017, work injury, the compensation judge explained that “Dr. Barron’s opinion that the employee sustained no injury that day lacks credibility.” (Memorandum at 8.)

Bang Printing maintains that Dr. Lynn’s attribution of 100 percent of the responsibility for employee’s current symptoms to the May 26, 2017, work injury is uncontroverted and failure to follow that opinion was error by the compensation judge. This argument relies on the asserted flaws in the opinions of Drs. Barron and McIvers. As discussed above, these are a matter of weight that were resolved by the compensation judge. Dr. McIvers told the employee that bone growth and scar tissue resulting from the 1998 surgery would require a more difficult fusion surgery. This impact supports the judge’s determination that apportionment is appropriate. Between the medical opinions of Drs. Barron and McIvers, there is a medical basis for some degree of apportionment.

Even if Dr. Lynn’s opinion had been unopposed, the judge was not obligated to follow that opinion where other evidence in the medical record supports the judge’s determinations.^[6] As of the May 26, 2017, work injury, the employee’s only preexisting low back condition was the 1998 surgery that resulted from the July 17, 1997, work injury. Imaging of the employee’s lumbar spine was assessed by a radiologist, who identified the employee’s pain generator as narrowed nerve root openings at the level of the employee’s 1998 back surgery. It was reasonable for the compensation judge to infer from this evidence that the condition of the employee’s low back following surgery was, at least in part, a cause of the employee’s low back pain following the May 26, 2017, work injury. This is substantial evidence on which to base a causation determination. Substantial evidence in the record, both from medical opinions and the employee’s medical records, supports the judge’s determination that apportionment is appropriate in this case.

Regarding the degree of apportionment, the Minnesota Supreme Court has set out as factors for apportionment: 1) the nature and severity of the initial injury, 2) the employee’s physical symptoms following the initial injury and before the second injury, 3) the nature and severity of the second injury, and 4) the period of time between the injuries.^[7]

The severity of the employee’s initial injury and the permanent nature of that injury supports some measure of responsibility being assigned to the July 17, 1997, work injury. At the same time, the length of time with minimal symptoms between that injury and the May 26, 2017, work injury weighs against apportioning significant responsibility to the earlier injury. This court has consistently held that where a range of apportionment determinations are supported by the record, this court will not substitute its judgment for that of the compensation judge.^[8] While reasonable minds might differ over the most appropriate percentages of apportionment, the employee’s condition following the July 17, 1997, work injury and the resulting disc replacement on August 21, 1998, supports some degree of apportionment to Bang Printing.

Bang Printing argues the compensation judge’s findings with respect to apportionment of liability are unsupported by the record and contain errors of law. The compensation judge concluded that 20 percent of the employee’s current lumbar pain and need for treatment is causally related to the 1997 injury and the remaining 80 percent is causally related to the 2017 injury. Apportionment of a compensable claim among two injuries is a question of fact for the compensation judge. This determination is not subject to precise formulas or bound by an expert opinion.^[9] Here, the compensation judge noted the employee’s complex medical conditions, a difficult recovery from a 1998 surgery followed by a 17-year period of symptom-free life and normal activity, the effects of his low back symptoms after the 2017 injury, and multiple expert opinions by several doctors. The judge concluded that a 20-80 apportionment was appropriate. From our review of the entire record, we acknowledge that the compensation judge could have apportioned liability in a number of ways; nevertheless, there is sufficient evidence in the record to support the 20-80 apportionment of responsibility for the employee’s disability between the two work injuries. We therefore affirm.