Most literature state no more then 3 or 4 steroid injections per year per joint. is this limited to one year or can you receive 3 or 4 steroid injections a year over multiple years?

It depends on the effectiveness of the injection. However, repeated steroid injections over the years may carry the risk of chronic steroid use such as early osteoporosis, easy skin bruising and possible increased risk of diabetes mellitus.

Agree that must use caution with repeat injections in a single joint. At some point, the medication can have an effect on the good tissues of the joint. If requiring that many injections, likely should consider a more permanent treatment.