In general, this is true. Patients are not treated on a first-come, first-served basis. They are seen based on how serious the condition is or how sick they are.
With limited funding, many operations are considered "elective" and not required. The patient can wait to reach the top of the waiting list for this operation, or he or she can go outside the system and pay for it privately.
A recent study on lumbar disc removal called discectomy from Canada reports rates for this operation. The reported rate of discectomy in the United States is 70 out of every 100,000. The rate is only 24 per 100,000 in Canada.