I would say he'd have no problems so long as his mobility isn't affected. Lots of different jobs to go for in the RAF though so more info might help.
This is a list of reasons his application would be rejected.
Your application would be rejected if:
* you suffer from asthma, or have done in the last four years;
* you have chronic lung disease, such as emphysema, bronchiectasis or cystic fibrosis, or you have active tuberculosis;
* you have had spinal surgery or you suffer from recurrent low back pain or spina bifida;
* you suffer from rheumatoid arthritis, or any other bone or joint disorder;
* you suffer from Crohn’s disease, colitis or kidney disorders;
* you suffer from epilepsy or multiple sclerosis;
* you suffer chronic blood disease, such as sickle cell disease, congenital spherocytosis, thalassaemia, HIV, AIDS, you carry hepatitis B or C, or you have had leukaemia or malignant lymphoma;
* you have schizophrenia, obsessive-compulsive disorder, post-traumatic stress disorder or you are dependent on alcohol or drugs;
* you have had your spleen removed;
* you have circulation problems such as Raynaud’s phenomenon or disease;
* you have diabetes; or
* you have a disease that needs long-term medication or replacement therapy.
to be fair I suspect this one doesn't mean properly repaired broken limbs
you suffer from rheumatoid arthritis, or any other bone or joint disorder