Hip Arthritis and Total Hip Replacement
What is hip arthritis?
Hip arthritis is a general term used when patients have cartilage loss within the hip joint. The most common cause is osteoarthritis, or “wear and tear” arthritis. This can happen in anyone, though there can be some genetic predisposition. It is most common in females in the 5th and 6th decades of life, but can occur in younger and older patients as well. Other causes include post-traumatic arthritis (prior fracture or hip injury), inflammatory arthritis (such as rheumatoid or lupus), congenital deformity (such as hip dysplasia or Perthe’s disease), avascular necrosis (AVN, loss of the blood supply to the femoral head), and infectious arthritis.
What does the hip do?
The hip is a ball and socket joint where the thigh bone articulates with the pelvis. The ball is the head of the femur and the socket is called the acetabulum of the pelvis. The hip is surrounded by strong gluteal muscles that power the legs and allow for normal function. The hip generally has a wide range of motion that allows the legs to be placed in a wide variety of positions. It is part of the “core” of the body, and thus its function is essential for even simple activities.
The main symptom is pain. This pain is typically located in the groin, or in the front of the hip. It can also occur deep in the buttock. Pain that is in the low back or located on the side of the hip are typically NOT due to hip arthritis, but could represent back problems or bursitis. Pain is typically worse with activity and improves with rest. Simple walking can cause pain in severe arthritis, and it can even wake patients up at night. Often times, the hip will become stiff, which makes it difficult and painful for patients to do simple activities such as put their socks and shoes on, get into and out of a car, and squat down. As these symptoms worsen, patients become more and more disabled. Arthritis is typically a progressive disease, meaning that it tends to get worse as time goes on. However, patients will sometimes experience “flare-ups” where they will experience a sudden worsening in symptoms for a period of days to weeks.
The diagnoses is based on a patient’s symptoms, physical exam, radiographic findings (such as x-rays or an MRI), and occasionally diagnostic hip injections. Physical exam findings include a limp, hip stiffness, and sometimes cracking or popping in or around the hip. When the surgeon moves the hip to the extremes of range of motion, patients experience pain in the groin or buttock. Typically, pain is worst when the hip is flexed and internally rotated.
On x-ray, there is a loss of cartilage, where there is bone-on-bone contact between the femoral head and acetabulum. As arthritis progresses, bone spurs (also called osteophytes) begin to form, which leads to impingement, pain, and loss of motion. Frequently, cysts of joint fluid form within the bone around the arthritic joint.
Simple x-rays are typically sufficient and MRIs are not needed for straight-forward osteoarthritis. However, MRIs are sometimes used in cases where the surgeon is concerned about avascular necrosis (loss of blood supply to the femoral head), labral tears, or tumors. Sometimes, an MRI is done in cases where pain is much more severe than one would expect based on the degree of arthritis seen on x-ray.
Injections into the hip are sometimes used to aid in the diagnosis of hip arthritis as well. Pain in the hip region can sometimes be caused by back pain that is referred to the hip. In cases where this is a concern, the surgeon may recommend injecting a local anesthetic (numbing medicine like lidocaine) into the hip joint. If a hip injection takes the pain away, even for a short time, then the pain is coming from the hip joint itself. If a hip injection does not help the pain, then it is likely that the pain is coming from somewhere else.
Non-surgical treatment options
Your surgeon will take your specific lifestyle needs and past history into account when recommending treatment for hip arthritis. The initial treatment for hip arthritis is almost always non-operative. Non-operative treatments include oral medications (such as anti-inflammatories or Tylenol), activity modifications, weight loss, physical therapy, gait aids (such as a cane or walker), and hip injections. There are potential benefits and risks to all types of treatment, so it is important to work together with your doctor to create a plan that is appropriate to your situation.
Is it possible to re-grow cartilage?
There are ongoing studies into technology to regrow cartilage, but there is currently no way to do so within an arthritic joint. Claims that injections or medications can regrow cartilage or cure arthritis are not supported by any scientific evidence.
How do I know when it is time for a hip replacement?
You should not undergo a hip replacement unless you have significant pain that keeps you from doing even simple activities. You have tried the non-operative treatment options listed above for at least three months, and you continue to have severe pain and limitations despite these interventions. X-rays or MRI should also show severe hip disease that corresponds to your pain. It is possible to have advanced arthritis on x-rays but minimal pain. Because of this, it is not possible for a doctor to accurately predict how long your native hip joint will last.
Total Hip Replacement
What are the surgical options for hip arthritis?
The only surgical treatment for hip arthritis is a hip replacement. Once a hip becomes degenerative, other surgical options such as hip arthroscopy or osteotomy are generally not advised.
What is a hip replacement?
During a hip replacement, your surgeon removes the ball (femoral head), which is arthritic and worn out. The bone of the socket (acetabulum) is machined down to remove any remaining arthritis and cartilage. A porous metal cup is placed into the socket. Eventually, your bone will grow into the metal so that it becomes part of you, a process that typically takes 2-3 months. Until bone grows into the implants, the cup is held in position by friction and oftentimes screws that hold the cup to the bone. A plastic liner is then placed within the metal socket.
On the femoral side, the femoral canal (marrow canal) is machined so that a metal stem can be placed. This stem may be either cementless (meaning that your bone will grow into it) or cemented (held in place with bone cement). A metal or ceramic ball is placed onto the femoral stem. This ball then articulates with the plastic liner.
What is a hip approach?
A hip “approach” refers to the route a surgeon uses to access or expose the hip joint. This relates to the location of the incision, as well as the structures that are encountered and need to be addressed to get to the hip. While there are many variations regarding hip approach, these generally fall into three categories: Direct Anterior, Posterior, and Anterolateral. A hip replacement can be successfully done through any of these approaches with good results. There are pros and cons to each approach.
There are potential complications to any surgical procedure. Complications can include infection, dislocation (or the hip coming out of place), loosening of the parts, wear of the plastic, leg length discrepancy, nerve or blood vessel damage, and fracture of the bone around the implants. Fortunately, complications are uncommon, but when they do occur, additional surgery may be required. Make sure to discuss these potential complications with your surgeon prior to surgery.
How can I minimize my risk of complications?
It is not possible to have any surgery without potential risks or complications. However, there are certain aspects of your health that can be optimized prior to surgery, which have been shown to improve outcomes.
Diabetes – Poorly controlled diabetes can increase the risk of complications such as wound healing problems or infection. Your surgeon may check a blood test called hemoglobin A1c, which determines how well your diabetes in controlled. If ther A1c is too high, your surgery may be delayed until better blood sugar control can be accomplished.
Smoking – Smoking tobacco is one of the biggest risk factors for wound complications and infection. Cutting back or quitting smoking would lessen your risk of infection around the time of surgery.
Obesity – Patients who are overweight are more likely to have their joints wear out at a younger age. There is also an increased risk of infection and component failure, particularly for patients with a BMI of more than 40. BMI can be easily calculated online. In some patients, weight loss will be required prior to surgery to minimize surgical risk.
Specific recovery protocols may vary from patient to patient, but we typically allow full weight bearing immediately following surgery. You will need to use a walker or crutches initially, but may wean off of them at your own rate. The hospital stay for hip replacements has become much shorter in recent years – most patients now go home either the day of (outpatient), or the day following surgery (one night in the hospital). Often times, patients are most concerned about pain management. Managing pain differs from patient to patient so it is important to communicate with your doctors about what is working and what isn’t. Most patients will not require formal physical therapy following a hip replacement surgery. The best form of exercise initially following surgery is simple walking. Though full recovery continues for a full year after surgery, patients can return to most activities by 6-10 weeks.
Overall, the outcomes of hip replacement are excellent. Patients can essentially return to any activity once recovered from surgery, though it is generally recommended that patients avoid repetitive high impact activities to prolong the lifespan of the hip replacement materials. These days, in the absence of complication, we expect hip replacements to last multiple decades.
Why should I choose ROC?
Your best chance at an excellent outcome is to get things done right the first time. At Reno Orthopedic Clinic, our Joint Replacement Team are fellowship-trained subspecialists who focus solely on joint replacement. Because of this, we have the experience and expertise to treat the full spectrum of hip arthritis, from basic nonoperative treatment to complex revision surgery.