Distal radius fracture orif surgery 20 days aft inj, no restrictions or cast, went to wrk d except 3 post op, could this cause nonunion now in 8th mnt?

Possibly: Searching for the reason for the non-union is not as productive as identifying the solution.Delayed union is nomally defined as three months without x-ray evidence of healing. Non union 6 months-so you need a solution-usually repeat surgery with bone graft.

Many factors in non : Union and one may be premature working , but other could be the Ibuprofen or other metabolic issues.