[T]he proper focus of the inquiry is not on the extent to which the condition has caused difficulty in the past; it is on the potential that the condition may combine with a work-related injury in the future so as to cause a greater degree of disability than would have resulted in the absence of the condition.
Knisley v. Charleswood Corp., 211 S.W.3d 629, 637 (Mo. App. 2007) (citation omitted).
We are convinced that employee's preexisting disabilities were serious enough to constitute hindrances or obstacles to employment for purposes of $\S 287.220$ RSMo. Employee provided evidence of preexisting right knee, left knee, and left ankle conditions. Each of these conditions had the potential to combine with future work-related injuries so as to cause greater disability than would have resulted in the absence of these conditions. Dr. Stuckmeyer rated employee's preexisting left knee condition at 30\% permanent partial disability, right knee condition at 30 % and left ankle condition at 25 %, and we have found these opinions of Dr. Stuckmeyer to be credible. We conclude that at the time he sustained the 1997 occupational disease, employee suffered from preexisting permanent partial disabilities of his left knee, right knee, and left ankle, and that each of these conditions constituted hindrances or obstacles to his employment or reemployment.
We now proceed to the question whether employee met his burden of establishing entitlement to compensation from the Second Injury Fund. Section 287.220.1 RSMo provides, in relevant part, as follows:
If the previous disability or disabilities, whether from compensable injury or otherwise, and the last injury together result in total and permanent disability, ... the employer at the time of the last injury shall be liable only for the disability resulting from the last injury considered alone and of itself; except that if the compensation for which the employer at the time of the last injury is liable is less than the compensation provided in this chapter for permanent total disability, then in addition to the compensation for which the employer is liable and after the completion of payment of the compensation by the employer, the employee shall be paid the remainder of the compensation that would be due for permanent total disability under section 287.200 out of a special fund known as the "Second Injury Fund" ...
The foregoing section requires us to first determine the compensation liability of the employer for the last injury, considered alone. If employee is permanently and totally disabled due to the last injury considered in isolation, the employer, and not the Second Injury Fund, is responsible for the entire amount of compensation. See ABB Power T \& D Co. v. Kempker, 236 S.W.3d 43, 50 (Mo. App. 2007).
We have found that, as a result of the last injury, employee sustained a 50\% permanent partial disability of the body as a whole referable to throat cancer. Dr. Stuckmeyer opined that employee is permanently and totally disabled as a result of the work injury in combination with employee's preexisting conditions of ill, and we have found this testimony from Dr. Stuckmeyer credible. We conclude that employee did not sustain enhanced permanent partial disability, but rather that employee is permanently and
totally disabled due to a combination of his preexisting disabilities in combination with the primary injury.
In sum, we are persuaded that employee has met his burden of establishing Second Injury Fund liability under § 287.220.1. We conclude that the Second Injury Fund is liable for permanent total disability benefits.