I am 1 year post op acdf c5/6 and ct with contrast shows hypodense focus on thyroid and a non fusion. no thyroid problems before this surgery, ?

ACDF Pseudo: First, the thyroid nodule is unrelated. At 1 year postop i'd expect to see some form of fusion bone, even if infuse was used (some docs use this, though high rate of complications, but bone formation is gradual). Nonetheless, pseudoaethrosis (fusion fail) does not equal pain. Presumably you had films due to persistent pain. If a symptomatic pseudo, treat with posterior fusion and iliac graft.

It sounds like there: Are 2 separate issues going on here. First, you need to get your thyroid findings further evaluated. You may have developed this sometime after the surgery or it may have been present before but not detected on a preop test especially if no contrast used. About 10% of single level fusions in the neck do not fuse. Thyroid function can affect fusion rate as can other factors like smoking.