North Carolina Subscriber
Answer: If the patient has localized osteoarthritis only, you should use 715.31 (Osteoarthrosis, localized, not specified whether primary or secondary, shoulder region). You would commonly use this code for standard shoulder osteoarthritis patients.
You shouldn't report 716.11 (Traumatic arthropathy, shoulder region) unless the patient had traumatic arthritis, which is normally secondary to an old injury. Scan your surgeon's notes to see whether he describes arthritis that fits this description. If the arthritis isn't considered "traumatic," 715.31 is your best bet.