Hip replacement surgery, also known as hip arthroplasty, is a safe and effective surgical procedure performed to treat a variety of conditions which result in a damaged or worn-out hip joint, such as hip osteoarthrosis (OA); the goal of the surgery is to replace the joint which is causing pain, disability, and affecting quality of life, with a prosthetic artificial joint made of metal alloys, ceramic and/or special plastics in order to restore function.
Since the 1960s when total hip replacement was first performed, the procedure has seen an increase in demand, partly also because of the aging population. Nowadays it is one of the most common and most successful procedures in orthopedic surgery; in Canada there are about 60,000 hip arthroplasties performed each year while in the UK they are about 92,000. In the USA alone about 400,000 total hip arthroplasties are performed each year and this number is expected to grow to 630,000 by 2030.
Indications of hip replacement surgery
Hip arthroplasty is most commonly performed to treat hip osteoarthrosis, but its use is not limited to this disease nor it is indicated for all those who suffer from hip OA. The following are the main indications for hip replacement surgery:
- Primary Hip Osteoarthrosis. In this case, Arthroplasty is indicated only when all conservative treatments fail or when pain and disability caused by the disease affect too much the quality of life of the patient. Age is also an important factor when deciding whether or not to perform the surgery: patients below 60 years of age are likely to need a revision surgery to substitute the prosthetic hip during their lifetime, hence this aspect needs to be discussed; moreover, this younger group of patients needs to be willing to comply with post-op recommendations which include the avoidance of certain high-impact activities and exercises.
- Rheumatoid Arthritis. Patients suffering from hip osteoarthrosis secondary to inflammatory arthropathy are good candidates for total hip replacement.
- Femoral neck, femoral head or hip fractures. In some cases, a total or partial hip replacement might be indicated also in the treatment of fractures.
- Osteonecrosis of the hip.
- Hip Dysplasia.
- Tumors. Less frequent indication, but in some cases of hip joint primary or metastatic tumors a total hip arthroplasty might be performed.
Localized or systemic infection (sepsis) is the main contraindication for this surgery. Other contraindications for which the physician evaluation is required are:
- Severe osteoporosis
- Inability to follow the surgeon’s instructions post operatively, such as in the case of patients with dementia
- People who will engage in strenuous activities that will put under great stress the implanted joint
- Diseases that might make it too risky to perform the operation, such as heart disease or kidney disease
- Behaviors that will result in non-adherence with post-op instructions, such as drug abuse or alcoholism
The Hip replacement surgical procedure
There are four main operative approaches to the total hip replacement.
- Anterior approach.
- Lateral approach.
- Posterior approach.
- Minimally invasive approach.
All of the approaches are safe and successful and each one provides different advantages and disadvantages. The surgeons will choose the approach they think is the best and for which they have more experience and confidence. At this time, there are no studies recommending one approach over the others.
The patient lies on the operating table either supine (anterior and lateral approaches) or on the side which is not being operated (lateral and posterior approaches).
The incision will be 5-10 inches long (12-25 centimeters) and will have a slightly different shape and location based on the chosen approach.
To expose and reach the hip joint the surgeon needs to dissect the muscles of the thigh. Different approaches allow for different muscle dissections. After exposing the hip joint the surgeon proceeds to remove the damaged bone and cartilage; the prosthetic socket will be implanted in the pelvic bone and a prosthetic head (ball shaped) will be implanted in the femur.
After verifying the proper positioning of all components and having them secured in place, the surgeon repairs the damaged soft tissues, such as the muscles, and finally closes the skin incision with stitches or staples.
The anterior, lateral and posterior approach, by dissecting different muscles, might have a different recovery time before returning to normal activities as well as different risk of post-op joint dislocation, but current review studies have been inconclusive.
The new minimally invasive approach for total hip replacement is performed with one (3-6 inches or 7-15 centimeters) or two (2-3 and 1-2 inches or 5-7,5 and 2,5-5 centimeters) smaller incisions. This approach is not suitable for all the patients nor all providers and clinics do perform this approach. Eligible patients are usually young, healthy, thin and motivated in undergoing the rehabilitation process post-op. The main benefit of the minimally invasive hip replacement is that there is less soft tissue damage (muscle dissection) which implies a less painful and quicker recovery post-op, with faster return to normal life activities.
Pre-op preparation for hip arthroplasty
The surgeon will need to know your medical history, known allergies, medications taken and will ask you some questions about your health. He will ask about your symptoms and expectations. Will perform a physical examination and will prescribe a hip x-ray; in some cases, an MRI might be prescribed too. There will be also blood tests and an ECG before surgery as well as an anesthesiologic consult.
If you smoke, it is advised to quit smoking at least a couple of weeks before surgery; smoking impairs the wound healing process and raises the risk of post-op complications too.
There is some blood loss during hip arthroplasty, hence you might be advised to donate your own blood before the procedure.
Losing weight before undergoing the procedure and having a BMI within normal range can speed up the recovery. Building some muscles can make the recovery easier too; talk to a physical therapist and to your doctor about it.
You might want to do some social and home planning beforehand: you won’t be able to perform normal life activities for a while such as doing laundry, cooking, shopping, bathing. You might want to have people around you to help you out with these tasks. You might want to buy also a raised toilet seat, prepare a stable chair of the right height with a firm cushion, flat closed shoes, handrails, crutches as well as removing carpets or cables that increase the risk of fall. A physical therapist or your surgeon can advise you on these little tips that will make the recovery easier and safer.
Risks of total hip replacement
The arthroplasty is considered a safe procedure, but like any other surgery or medical procedure there are risks involved. The main risks are:
- Bleeding during surgery or after surgery.
- Blood clots and DVT
- Injury to nerves caused by the dissection
- Post-op hip joint dislocation
- Unsuccessful surgery (function is not restored and/or pain is still present after surgery)
- Changes in leg length
- Fractures of healthy bone during surgery
Recovery after the arthroplasty
The success of the surgery will depend greatly on how you behave after surgery. The rehab process begins on the same day of surgery, as soon as you recover from the anesthesia, or the day after surgery depending on your surgeon and PT indications. Strictly following their instructions is the best way to guarantee an optimal outcome.
You will be advised to wear compression stockings and will have to take blood thinning medications to avoid the risk of deep vein thrombosis (DVT).
After 3-4 days you should be discharged from the hospital and sent home or to a rehab facility.
Stiches or staples will be removed after 10-14 days. Until then you should follow the surgeon’s advices on how to keep the surgical wound clean and dry.
Avoiding certain movements, such as flexing the hip past 90 degrees or intrarotating/extrarotating the operated leg is extremely important to avoid complications such as dislocation of the joint. Exercising daily following the program from the physical therapist is of utmost importance too for a speedy recovery and to get back to all normal activities.
After about 4 weeks you should be able to return to work and drive.
Heavy lifting should be avoided for the first 2-3 months after surgery; you will keep recovering and gain strength for 6-12 months after surgery.
Costs of total hip replacement surgery
Costs vary depending on what is included in the package (medications, physical therapy, surgeons fee, materials, …), on the surgeon and on the clinic/hospital.
On average, in the USA a total hip replacement costs start at 32,000-45,000+ USD.
In Australia the price starts at about 20,000-40,000+ AUD (13,000-25,000+ USD)
In the UK the cost is about 8,500-17,000+ GBP (11,000-22,000+ USD)
In Thailand the price is about 260,000-400,000+ THB (8,000-12,000+ USD)
How long does the prosthetic joint last?
From current data, it seems that 95% of hip arthroplasties won’t require revision at the 15 years mark. About 85% will last at least 20 years. At 25 years, the survival is about 60%. With the advent of new techniques and materials we can expect total hip replacements to last even longer.
What activities should be avoided after having total hip arthroplasty?
Up to 12 months after hip replacement surgery you should avoid rotating internally or externally the operated leg, avoid crossing the legs, avoid bending the hip more than 90° (both by raising the operated leg and by bending the waist forward). High impact activities, stressful for the joint, might have to be avoided even after the first 12 months. Your surgeon will advise you on all of this.
- Essentials in total hip arthroplasty.
J Parvizi, B Klatt – SLACK Inc, 2013
- How long does a hip replacement last? A systematic review and meta-analysis of case series and national registry reports with more than 15 years of follow-up
JT Evans, JP Evans, RW Walker – The Lancet, Feb 2019
- Surgical Approaches for Total Hip Arthroplasty
VM Moretti, ZD Post – Indian Journal of Orthopaedics, Jul 2017
- Projected Volume of Primary Total Joint Arthroplasty in the U.S., 2014 to 2030.
M Sloan, A Premkumar, NP Sheth – Journal of Bone and Joint Surgery, 2018
- The American Academy of Orthopaedic Surgeons (AAOS)