Received settlement for an on the job injury from third party insurer. Do I have to pay back workers comp?

I reported this injury to workers comp as being on the job, but decided to go the route of seeing a chiropractor OUTSIDE the workers comp system, and did not receive any wage replacement or therapy paid for by workers comp. This was way back in 1997. Would I still be required to pay workers comp back the settlement amount? This is in California by the way.