The National Institute for Health and Clinical Excellence (NICE) has issued full guidance to the NHS in England, Wales, Scotland and Northern Ireland on metatarsophalangeal joint replacement of the hallux.
Osteoarthritis is a common condition in which the surface of the joint becomes worn and the adjacent bone thickens and forms osteophytes. If severely affected, the joint becomes painful and stiff.
Rheumatoid arthritis is a chronic inflammatory disease that destroys the joint and will eventually lead to end stage osteoarthritic changes.
Both kinds of arthritis commonly affect the metatarsophalangeal (MTP) joint at the base of the big toe. The joint may become predominantly stiff (hallux rigidus) or deformed (hallux valgus).
Conservative treatments include exercise, physiotherapy, analgesics, non-steroidal anti-inflammatory tablets and cream, and steroid injections into the joint. Severe cases that do not respond to conservative measures may require surgery. If the only problem is an osteophyte on the surface of the joint, this may be trimmed (cheilectomy), but the three main surgical options for treating the whole joint are fusion, simple excision of the arthritic joint (Keller’s procedure) and joint replacement with an artificial implant.
MTP joint replacement is carried out under general or spinal anaesthesia using tourniquet control. An incision is made over the joint and the capsule is exposed by dividing tissue and retracting tendon. The joint surfaces are excised and the medullary canals of the first metatarsal and proximal phalanx are enlarged to accommodate the prosthetic joint implant. A preliminary reduction with a trial implant is done to ensure a snug fit and the implant is then placed in the canal. The joint capsule is closed and a flexible splint is used postoperatively to maintain the correct position.
A code from one of the following OPCS-4 categories is assigned as appropriate:
W43.-Total prosthetic replacement of other joint using cement
W44.- Total prosthetic replacement of other joint not using cement
W45.- Other total prosthetic replacement of other joint
Plus the site code Z86.4 Metatarsophalangeal joint of great toe