Living with a worn or damaged hip joint can be painful and frustrating. It is possible that you find yourself doing fewer and fewer activities. Over time, even simple activities, such as walking a grocery store or getting up from a chair, can cause pain. However, you do not have to live like that. In many cases, an orthopedic surgeon can replace the hip joint that gives you problems. For most people, having a total hip replacement means returning to the movement without pain.
Indications for total hip replacement
The accepted indications for total hip replacement have changed and expanded over the years. An operation that was rather a salvage procedure for the elderly with low expectations, has evolved and has become the preferred surgery for a wide range of pathological conditions of the hip. The main indication for a Total Hip Prosthesis (THP) remains an advanced stage osteoarthritis. Currently, the population of the United States, which is increasingly older, suffers from an obesity epidemic (recent estimates show that a third of the US population is obese and with a body mass index greater than 30) and the The prevalence of primary osteoarthritis has increased significantly. When non-surgical treatment, such as losing weight, modifying activity amount, helping with cane and non-steroidal anti-inflammatory drugs, fail to relieve pain, total hip replacement offers a highly predictable treatment.
Historically, inflammatory arthritis, mainly due to rheumatoid disease, has been another common indication for THP. However, since the introduction several decades ago of anti-rheumatic drugs that modify the disease, the prevalence of advanced rheumatic destruction of the hip joint has decreased. Post-traumatic osteoarthritis secondary to fractures and / or dislocation of the acetabulum and proximal femur are still frequent indications for THP.
Osteonecrosis with segmental collapse of the head of the femur is a very frequent indication for total hip replacement. With the widespread use of corticosteroids for multiple medical conditions, the high rate of alcoholism in the general population and the increasing number of HIV patients taking highly active antiretroviral drugs, the incidence of osteonecrosis has increased in the United States and also in many other industrialized countries.
Displaced fractures of the neck of the femur in patients older than 60 years have become another frequent indication for THP. Several large retrospective studies, together with randomized clinical trials, have shown that THP provides a better functional outcome and fewer complications compared to traditional techniques of internal fixation or hemiarthroplasty for displaced fractures of the neck of the femur.
Less frequent indications for a THP are the primary or metastatic tumors of the hip joint and the after-effects of postinfectious arthritis.
Total hip replacement is a surgery that involves replacing the hip joint with artificial elements. The head of the femur is replaced by a component known as the femoral stem, which has a part that is inserted into the medullary canal of the femur and a spherical joint that replaces the head of the femur. The femoral rods are metallic, generally made of biocompatible alloys, which does not generate rejection by the organism in which it is implanted. The acetabular is replaced with an element known as acetabular cup, which is located in the same area where the joint cavity is in the pelvis, screws or cement are used to keep the cavity in place. In general acetabular cups are manufactured with a special type of plastic called polyethylene of utra high molecular weight that provides great strength and allow a smooth gliding surface.
An important factor in the decision to undergo hip replacement surgery is to understand what the intervention can and cannot do. Hip replacement surgery allows patients to experience a drastic reduction in hip pain and provides a significant in their ability to perform activities of daily living.
After the surgery, the patient will be able to walk without limit, swim, play golf, drive, ride a bicycle, dance, among others.
With normal use and activity, the material between the head and the cavity of each implant in the hip replacement begins to wear out. Excessive activity or overweight can accelerate this normal wear and tear and make the hip replacement loosen and painful. Therefore, most surgeons do not advise high-impact activities such as running, jogging, jumping or other high-impact sports.
With the proper modification of activities, hip replacements can last for many years.
Medical science has developed many types of hip prostheses. In general, they can be classified according to the way they are fixed to the patient’s bone and according to the material from which the head of the femur and the acetabular cup are made.
According to the corm form they are attached to the patient’s bone, there are cemented and uncemented prostheses. The cemented prostheses are attached to the patient’s bone by means of acrylic cement. At the time of surgery, it is inserted into polymethyl methacrylate bone cement. This hardens and forms a solid connection between the prosthesis and the femur. Without cement, the solid connection between the prosthesis and the femur depends on osseous ingrowth and osseointegration (as in the case of uncemented prostheses). The potential advantages of cement are the reduction of postoperative pain, since the prosthesis is fixed more firmly in the femur and the rate of long-term revision due to loosening of the prosthesis is reduced.
Depending on the type of material from which the head of the femoral stem and the acetabular cup are made, they can be metal-metal prostheses, if the head and acetabulum are metallic, polyethylene-cerimica, if the acetabulum is made of polyethylene and the head is of ceramic, and ceramica-ceramica, if both components are ceramic.
The decision of which type of prosthesis to use should be taken by the orthopedist specialist in joint replacements according to the characteristics of each patient.
Possible complications of surgery
Surface infection of the wound or deep infection around the prosthesis may occur. It could presented as a nosocomial infection (acquired in the hospital) or after medical discharge. It could happen even years later.
Minor wound infections are usually treated with antibiotics. More severe and deeper infections may require surgery to remove the prosthesis. Any infection in your body can spread to the replacement of your joint.
Blood clots in the veins of the leg or pelvis are the most common complication of hip replacement surgery. These clots can be life-threatening if they are released and travel to your lungs. Your orthopedic surgeon will design a prevention program that may include anticoagulant medications, supportive socks, inflatable leg covers, ankle exercises and early mobilization.
This occurs when the head comes out of the cavity. The risk of dislocation is greater in the first months after surgery while the tissues are healing. Dislocation is rare. If the head comes out of the cavity, a closed reduction can usually reposition it in place without the need for further surgery. In situations where the hip remains dislocated, additional surgery may be necessary.