A. Each insurer proposing to issue individual or group accident and sickness insurance policies providing hospital, medical and surgical or major medical coverage on an expense-incurred basis, each corporation providing individual or group accident and sickness subscription contracts, and each health maintenance organization providing a health care plan for health care services that provides coverage under such policy, contract or plan for diagnostic and surgical treatment involving any bone or joint of the skeletal structure shall not, under such policy, contract or plan delivered, issued for delivery or renewed in this Commonwealth on and after July 1, 1995, exclude coverage for such diagnostic and surgical treatment involving any bone or joint of the head, neck, face or jaw or impose limits that are more restrictive than limits on coverage applicable to such treatment involving any bone or joint of the skeletal structure if the treatment is required because of a medical condition or injury which prevents normal function of the joint or bone and is deemed medically necessary to attain functional capacity of the affected part.