Maureen Hikida was employed by Costco from November 1984 to May 2010. During this period, she developed a number of medical conditions, including carpel tunnel syndrome.

In May 2010, she took leave from work to undergo carpel tunnel surgery. Following the surgery, she developed chronic regional pain syndrome (CRPS), a condition that caused her debilitating pain in her upper extremities and severely impaired her ability to function.

An AME in orthopedics, Chester Hasday, M.D., found her permanently and totally disabled from the labor market.

He found that her permanent total disability was due entirely to the effects of the CRPS that she developed as a result of the failed carpal tunnel surgery. He further concluded that petitioner’s carpal tunnel condition itself was 90 percent due to industrial factors and 10 percent to nonindustrial factors. The WCJ awarded 90% disability after apportionment.

In a two-to-one decision, the Board affirmed the apportionment. The majority concluded: “To properly evaluate the issue of apportionment of permanent disability, it is necessary to ‘parcel out’ the causative sources of the permanent disability, nonindustrial, prior industrial and current industrial, and ‘decide the amount directly caused by the current industrial source.”

The Court of Appeal reversed and awarded unapportioned 100% disability in the published case of Hikida v WCAB.

The issue presented is whether an employer is responsible for both the medical treatment and any disability arising directly from unsuccessful medical intervention, without apportionment.

The Court of Appeal concluded that “despite significant changes in the law governing workers’ compensation in 2004, disability resulting from medical treatment for which the employer is responsible is not subject to apportionment.”

Here, there is no dispute that the disabling carpal tunnel syndrome from which petitioner suffered was largely the result of her many years of clerical employment with Costco. It followed that Costco was required to provide medical treatment to resolve the problem, without apportionment. The surgery went badly, leaving appellant with a far more disabling condition — CRPS — that will never be alleviated.

California workers’ compensation law relieves Costco of liability for any negligence in the provision of the medical treatment that led to petitioner’s CRPS. It does not relieve Costco of the obligation to compensate petitioner for this disability without apportionment.

“Our review of the authorities convinces us that in enacting the “new regime of apportionment based on causation,” the Legislature did not intend to transform the law requiring employers to pay for all medical treatment caused by an industrial injury, including the foreseeable consequences of such medical treatment.”