Reaching state pension age will have no affect on your injury pension. The injury pension is designed to compensate you for your loss of earning capacity due to the injury that you suffered whilst on duty. If you are still otherwise able to work at state pension age, then you will still have a loss of earning capacity to be compensated for.
The infamous Home Office circular 46/2004, suggested that at state pension age, the pensioner no longer had any earning capacity and the injury pension should be reduced to its lowest band.
Once a former officer receiving an injury pension reaches the age of 65 they will have reached their State Pension Age irrespective of whether they are male or female. The force then has the discretion, in the absence of a cogent reason otherwise, to advise the SMP to place the former officer in the lowest band of Degree of Disablement. At such a point the former officer would normally no longer be expected to be earning a salary in the employment market. A review at age 65 will normally be the last unless there are exceptional circumstances which require there to be a further review.
This advice was later deemed to be unlawful because a person cannot suddenly lose their ability to work overnight simply because they have reached state pension age (currently 65 and rising), or are in effect just a day older.
Of course, regulation 37(1) allows forces to review your injury pension if a suitable interval has passed, but this suitability is not dependent upon reaching any particular age.