Total hip prosthesis

Introduction

Total hip prosthesis (THP, also called total hip arthroplasty THA or total hip replacement THR) is one of the most successful orthopaedic procedures performed today. For patients with hip pain due to a variety of conditions, THP can relieve pain, can restore function, and can improve quality of life. Sir John Charnley, a British orthopedic surgeon, developed the fundamental principles of the artificial hip and is credited as the father of THP. He designed a hip prosthesis in the mid to late 1960s that still sees use today. It is estimated that over 300,000 total hip arthroplasties are performed each year in the United States alone.
The normal hip functions as a “ball-and-socket” joint. The femoral head (ball) articulates with the acetabulum (socket), allowing smooth range of motion in multiple planes. Any condition that affects either of these structures can lead to deterioration of the joint. This, in turn, can lead to deformity, pain, and loss of function. The most common condition affecting the hip in this way is osteoarthritis. Other conditions that may affect the hip adversely include inflammatory arthritis (rheumatoid arthritis, psoriatic arthritis, spondyloarthropathies, etc), developmental dysplasia, childhood hip disorders (Legg-Calve-Perthes disease, slipped capital femoral epiphysis, etc), trauma, neoplasms, and osteonecrosis.
THP is a procedure whereby the diseased articular surfaces are replaced with synthetic materials, thus relieving pain and improving joint kinematics and function

THP is an elective procedure and should be considered as an option among other alternatives. The decision to proceed with THP is made with an understanding of the potential risks and benefits. A thorough understanding of both the procedure and the anticipated outcome is an important part of the decision-making process. For the appropriate candidate, THP can be a life-altering procedure that relieves pain, improves function, and enhances quality of life.

OUTCOMES

Published results of total hip arthroplasty (THP) demonstrate excellent clinical, functional, and radiographic results. These results vary depending upon the implant, the surgical technique, the type of fixation, the biomaterials, the patient’s age, and a myriad of other factors. THP may be performed successfully in patients ranging from the very young to older adults (over 80 years of age). However, young and active patients must be made aware that premature failure of the replaced joint may occur if activity levels are not reduced. Impact activities, manual labor, heavy lifting, and high-intensity sports should be reduced.

Direct Anterior Approach (DAA)

There are several access routes to the hip joint to perform a total hip prothesis. In the “anterior approach” the hip reached between two muscles groups. These muscles lie on the front of the hip joint, hence the name.

In recent years, this approach is gaining popularity. Other names in the literature for this approach are: ASI approach (anterior supine intermuscular) or Smith Peterson approach. This mode of operation is not new. By the end of the 19th century, this approach was already used for other purposes. In France, from 1947, doctor Judet and other French orthopaedic surgeons performed hip prostheses in this way (hence it is also called the French approach). Over the last 10 years, the technique has been rediscovered and is increasingly being used for hip prostheses. By 2016, 21% of the hip prostheses were placed in the Netherlands through this technique (source LROI). Dr Henkus and Dr van der Lugt started hip arthroplasty with this technique since 2006 and have many years of experience (>2000 hip protheses each).

You will get an anesthetic before your hip surgery. This may be:
regional (numbs you from the waist down)
general (puts you completely to sleep)

The operation uses a natural interval between two muscle groups lying in the front of the hip. The scar is therefore also slightly more in the front than usual. No muscles are detached or cut making this approach less painful en the hip more stable afterwards.
The preparation of the bone for placement of the prosthesis, the duration of surgery and the general risks such as the occurrence of an infection are like other approaches.
The average operation time is 50-60 minutes.

Actinia Hip System with a Cobalt Chrome head (with a Titanium Nitride coating, golden color) and the EcoFit,  with a high crosslinked polyethylene insert from the firm Implantcast GmbH, Buxtehude, Germany

Implantcast has a worldwide sales network with more than 65 international sales partners.

Unlike other approaches, no muscles are cut to reach the hip joint. The main muscles for a stable hip and a normal pattern remain completely out of range. Also, damage to major nerves around the hip joint is much less common in this technique. As a result, limping and muscle weakness after surgery is no longer a problem. Also, the chance of dislocation of the hip is smaller than in other approaches to the hip

The wound that is made with this method is no smaller than other operating techniques, although we try to minimize the wound.

The scar is between 8 and 15 cm long. The gain of the anterior approach is not so much a smaller scar, but keeping the muscles intact that are important for walking and for the stability of the hip. This results in less pain, a stable hip and easier recovery during the first months after surgery.

A disadvantage of this approach is the risk of nerve damage that provides the feeling of the skin on the outside of the upper leg (desensitization area around 10 x 10 cm). This occurs in approximately 5 – 10% of cases. Fortunately, this is often transient, and patients (1 to 2%) who do hold an (often small) area of ​​altered or reduced feelings do not describe this as annoying.

Due to the extensive experience of both surgeons with this technique, this approach can be practically applied to all patients. Not suitable, however, are patients with extreme obesity or patients with a special hip anatomy.

Because the muscles around the hip remain intact, you will experience greater stability. The post-op treatment can therefore also be less strict. For example, you can:

• walk out of bed and walk a few steps (with one or without crutches) on the day of surgery.
• you can go home the same day. (Usually, patients go home one or two days after surgery.)
• use crutches as long as needed (Usually one or two weeks)
• sleep on the side.
• use a home trainer
• driving (once walking with one crutch). Normally after 2-3 weeks.
• do not need to take any special precautions at home.

Nevertheless, consider a period of two to three months to recover before your body regained its suppleness and strength.