Total hip arthroplasty (THA) replaces a damaged hip joint with an artificial implant, effectively treating debilitating hip pain, often caused by severe osteoarthritis. While THA offers significant improvements in mobility and quality of life, it is a major surgery that carries risks. Determining patient eligibility requires surgeons to balance potential benefits against the increased risk of severe complications or implant failure. The decision relies on assessing a patient’s overall health, the local condition of the hip joint, and their capacity to adhere to the post-operative recovery protocol.
Systemic Health Concerns and Surgical Risk
Conditions that compromise a patient’s overall health transform elective hip replacement into a high-risk procedure. Uncontrolled severe cardiac disease is a serious contraindication, as the stress of anesthesia and blood loss can precipitate a heart attack or acute heart failure. Patients with advanced pulmonary insufficiency, such as severe pulmonary hypertension, also face elevated risks due to difficulty managing oxygen and blood pressure fluctuations during and immediately following the operation.
Active systemic infection, such as sepsis or bacteremia, is an absolute reason to postpone surgery. Circulating bacteria inevitably colonize the new prosthetic joint, leading to catastrophic periprosthetic joint infection (PJI). Uncontrolled diabetes mellitus similarly impairs the body’s ability to heal and fight infection. Patients with persistently high blood sugar levels have a higher risk of wound complications and early mortality following THA, often requiring medical optimization before the procedure can safely proceed.
Severe chronic conditions affecting organ function, including end-stage kidney or liver failure, increase surgical morbidity and mortality, often outweighing the benefits of elective hip replacement. Surgeons require medical clearance from specialists, such as cardiologists or pulmonologists, to confirm that underlying conditions are optimized enough to withstand the physiological stress of the operation. If these severe systemic issues cannot be medically controlled, the patient is considered too high a risk for surgery.
Localized Joint and Bone Conditions
Issues specific to the hip joint and surrounding tissue can prevent the artificial implant from securing properly, compromising the procedure’s success. An active infection within the hip joint, such as septic arthritis or osteomyelitis, is an absolute contraindication until completely eradicated. Bacteria rapidly form a protective biofilm on the implant surface, making the resulting infection nearly impossible to treat without removing the joint entirely.
Insufficient bone stock presents a significant mechanical challenge, often stemming from severe osteoporosis, previous trauma, or advanced disease. If bone quality is poor, implant components cannot achieve stable fixation, increasing the risk of intraoperative fracture or later aseptic loosening. Without a strong bony foundation, the artificial joint is prone to early failure because the bone cannot grow into the implant surface, a process called osseointegration.
Severe neuromuscular deficits are a limiting factor, directly impacting a patient’s ability to rehabilitate and control the new joint. Conditions causing paralysis, severe muscle weakness, or uncontrolled spasticity can lead to mechanical instability and a high risk of post-operative hip dislocation. Even if the surgery is technically perfect, the patient must possess adequate muscle control to protect the implant and participate in the required physical therapy for a successful functional outcome. Furthermore, severe peripheral vascular disease in the limb leads to poor blood flow around the surgical site, impeding wound healing and increasing the likelihood of infection.
Patient Compliance and Lifestyle Factors
Factors related to a patient’s behavior and physical habits can undermine the long-term success of hip replacement, often leading to early implant failure. Severe obesity, defined as a Body Mass Index (BMI) of 40 or greater, is a strong relative contraindication. Obesity places excessive mechanical stress on the implant, accelerating the wear of the bearing surface, raising the risk of component loosening, and elevating the chance of post-operative hip dislocation.
Severe obesity is also associated with an increased rate of wound complications and periprosthetic joint infection, which is the most feared complication of THA. Active substance abuse, including alcohol or illicit drug use, complicates post-operative care by impairing the patient’s ability to manage pain safely and follow instructions. Patients with a history of injection drug use have a high rate of septic failure, leading some surgeons to recommend documented abstinence for at least a year before considering the operation.
Severe cognitive impairment, such as advanced dementia, can render a patient unable to understand or comply with the crucial hip precautions necessary during the first few months after surgery. Failure to follow restrictions, such as limits on hip flexion and internal rotation, drastically increases the risk of dislocation. Patients with unrealistic expectations, who believe the new joint allows them to return to high-impact athletic activities, may place undue stress on the implant, leading to premature wear and mechanical failure.