Hip replacement is an effective and successful surgical procedure for end stage osteoarthritis of the hip when conservative treatment has failed. The implantation of a hip prosthesis can also be an indicated solution for numerous hip pathologies, such as:

• primary arthrosis (i.e. without an identifiable cause) and secondary arthrosis (i.e. caused by other hip pathologies)
• rheumatoid arthritis
• aseptic osteonecrosis of the femoral head
• hip dysplasia
• ankylosing spondylitis
• psoriatic arthritis
• medial femoral neck fracture in patients over 60 years old
• secondary tumor lesions

The damaged components of the hip can be different, so the prosthesis can replace:

• the femoral head alone: endoprosthesis or partial prosthesis;
• the head of the femur and the acetabular cavity: arthroplasty or total prosthesis.

The total hip prosthesis is basically made up of two components: the femoral component or stem of the prosthesis, which is inserted into the medullary canal and the cotyloid component fixed to the iliac bone of the pelvis or cotyle of the prosthesis.

Endoprosthesis replaces only the femoral part which will articulate with the patient’s cup. It is used only in very elderly patients who have suffered a fracture of the femoral neck; in such patients, with serious functional limitations and/or with significant general diseases, the choice to apply an endoprosthesis reduces surgical times and therefore operating risks and allows a rapid recovery of verticality and walking.

There are also various types of prostheses, both in terms of materials and models, among which the surgeon can choose.

Standard total hip replacement implants are typically made up of approximately four individual components: titanium and cobalt-chromium implants, that are considered highly biocompatible; ceramic and Cobalt-chromium, that present a very hard surface and are extremely resistant to scratching or other damage, and Polyethylene, a plastic material commonly used for hip replacement liners. This material has provided good to excellent results when paired with ceramic or cobalt-chromium balls. 

Before carrying out any intervention, an accurate diagnosis by a specialist is essential. Usually an x-ray is necessary to confirm the diagnosis and a possible (and not always necessary) magnetic resonance imaging, as well as an always recommended study of the patient’s soft tissues.

The operation for the implantation of the hip prosthesis is performed under general or epidural anesthesia with sedation.

In most cases it is possible to carry out this with minimally invasive procedures with a significant reduction in recovery times after the operation, guaranteeing early mobilization. Using the minimally invasive technique for implanting the prosthesis, the periarticular soft tissues are safeguarded, the joint capsule is reconstructed and the skin incision is reduced to 7-8 cm. Today modern hospitals follow Fast Track protocols, according to the principles of Tissue Sparing Surgery (TSS), which involves a rather short stay in hospital, a very rapid and effective intervention with a significantly reduced administration of opiates compared to standards.

The average duration of hip replacement surgery is 60 minutes.

Already on the first day after surgery the patient will be able to sit up and begin to bend the knee and extend the hip. Once the first 48 hours have passed after hip replacement surgery (sometimes even earlier), the patient will be able to start walking with the help of the physiotherapist and the aid of two Canadian canes (crutches). Discharge from hospital occurs after an average of 4 or 5 days.

There are many variables in the speed of the operation, mainly linked to the age of the patients and general health conditions, but in the vast majority of cases recovery times are very short.

Following the procedure, a brief post-operative rehabilitation process becomes necessary to acclimate to the prosthetic and help the body adjust to its presence. The duration of recovery is influenced not only by the patient’s health but also by their dedication to the rehabilitation process. Some patients may recover in a few weeks, while others may require a bit more time.

The primary and significant benefit is the relief of pain, with nearly all patients experiencing substantial alleviation from arthritic hip pain. Following pain reduction, improved mobility is a key advantage, allowing individuals to resume walking without constraints. Enhanced hip function also aids in tackling common challenges associated with hip arthritis, such as climbing stairs, putting on socks, and rising from a chair. Notably, the positive effects are long-lasting, with current evidence indicating that 80-85% of hip replacements still function well even 20 years after the procedure.

The complication rate following total hip replacement is low. Serious complications, such as hip infection, occur in less than 1% of patients. Chronic diseases can increase the risk of complications. Patients with diabetes or obesity (BMI >30 kg/m²) have a higher complication rate and might benefit less from the total hip arthroplasty. Implant survival may be diminished in patients with a history of malignancy and in patients with diabetes or obesity.

Some possible complications include:

• It is the difference in length that may remain between the two lower limbs at the end of the operation; it may depend on intraoperative mechanical factors or on pre-existing local situations relating to the pathology in question (for example in hip dysplasia).
• Dislocation (risk less than 1%). It represents the disassembly with separation of the prosthetic components. It is statistically more frequent in the first two months following surgery and can be directly caused by incorrect postural attitudes and careless joint movements.
• Intraoperative fractures (risk less than 1%). It represents a rather rare complication, mostly linked to fragility of the femoral bone tissue due to osteoporotic causes.
• Allergies to metal components (previously unknown to the patient).
• Deep vein thrombosis and pulmonary embolism.
• Vascular and nervous complications. Intraoperative lesions of important vascular structures are quite rare; while the possibility of damage mainly due to stretching of the sciatic nerve and/or the femoral nerve should be noted, for which the risk can be quantified in the literature at approximately 2-3%.