Doctors have described tennis elbow for the last 130 years. Despite how old the problem is, its treatment remains a mystery. Surgery may offer reliable relief from the pain but other problems persist. For example, like you, many patients may still be limited in what they can lift and in their grip strength.
Most often results after surgery for tennis elbow can be improved with a rehab program. Control of pain and swelling are the early goals. Since you're several months past the operation strengthening exercises can be added.
Talk to your doctor about a rehab program. Maximum improvement may not be reached until a full year after the operation.