Joint arthroplasty is a surgical procedure done to replace a damaged joint with an artificial one called as prosthesis. In chronic arthritis, deformities most often start occurring at the smaller joints. The knee joint is also commonly affected. This begins as a flexion deformity and gradually results in cartilage damage (cartilage is connective tissue surrounding the joint that reduces friction). When such damages occurs, normal function is rarely regained even with oral medication and exercise. Activities such as rising from a chair, sitting on the floor and climbing stairs become very difficult. Joints can become completely stiff.
The aim of joint arthroplasty is to diminish the pain caused due to the cartilage damage. It is this pain which can lead to immobility, resulting in weak muscles around the joint.
The prosthesis consists of a metal plate and a plastic piece. The metal plate fits into the matching plastic piece. The metal plates used could be of steel, titanium or of alloys of cobalt. The plastic material is usually polythene, and is extremely durable.
First, general anesthesia is given. Then the affected joint is replaced by an artificial one. For instance, in cases of a knee joint, the damaged ends of the thigh bone and leg bone are resected and replaced by metal and plastic surfaces. Most recently, nylon plates are used through electro cauterization which gives the plates the desired shape in order to fit in perfectly, thus restoring near-normal movement.
In cases of a damaged or painful hip joint, the upper end of the thigh bone (ball) is replaced by a small metal into the socket (the socket is the damaged end of the hip bone or pelvis) forming the joint. These two surgeries are the most commonly done arthroplasties. Other areas include the ankle, shoulder, elbow and fingers.
Patients are encouraged to walk and stand a few days after surgery. Initially they should use crutches, splints or a walker. They may experience pain, soreness in the operated area, as the muscles are weak and tissues are healing. The pain often diminishes with time.
Infection is a common complication seen in most cases in the first few days immediately after the procedure. It is taken care of with antibiotics. Other important complications to be looked out for are blood clots. They are caused due to a reduced movement at the joint resulting in sluggish blood circulation. This is treated with blood thinning medications, use of elastic stockings and exercise. In rare cases, dislocations are also reported as there can be a failure to union. This results in adverse cases due to local reactions.
Exercise is the most important regime to follow after surgery. Initially, a trained physiotherapist teaches the patient important exercises to follow on the basis of the surgery and pain threshold. The movement of the joint then gradually improves and the physiotherapist lets the patient use the joint freely and pain free.
Penned by Dr. Rachita Narsaria, MD
2.Prieto HA, Berbari EF, Sierra RJ. Investigation performed at the Mayo Clinic, Rochester, Minnesota.: Acute Delayed Infection: Increased Risk in Failed Metal on Metal Total Hip Arthroplasty. J Arthroplasty. 2014 Apr 13. pii: S0883-5403(14)00239-3. doi: 10.1016/j.arth.2014.04.008.
3.Parvizi J, Parmar R, Raphael IJ, Restrepo C et al. Proximal Deep Venous Thrombosis and Pulmonary Embolus Following Total Joint Arthroplasty. Orthopaedic Surgery at the Rothman Institute, Thomas Jefferson University, Hospital, Philadelphia, Pennsylvania. J Arthroplasty. 2014 Apr 23.