In this situation, “approach” means how the surgeon enters the hip joint. Are they coming in through the front of the body or the back of the body? In North America, the most common approach used to be the posterior approach, through the back. However, the dislocation rate after surgery was higher than surgeons wanted to see. In response, the anterior approach, or opening the hip joint from the front, gained popularity. Over time both approaches evolved and improved. They became less invasive, decreasing the amount of muscle damage, and now have similarly low dislocation rates. The latest scientific data shows almost no difference in outcomes between the two approaches.
I’m well-versed in both approaches. My default is the anterior approach for patients having their first replacement, as I prefer the patient to be on their back during surgery. When they are on their back, it’s easier to use the X-ray machine or to check leg lengths. For revision surgeries, I use the posterior approach because it gives me more exposure and more access for a more complex surgery.
For knee replacements, data has shown that there is less pain and earlier return of strength when the quadriceps tendon is not cut. I perform the muscle sparing or subvastus approach and don’t cut this tendon if possible. If someone’s arthritis is too severe or their knee is too tight, sometimes this approach is not possible and a more traditional approach is needed.
While replaced joints work well, they are not equal to a non-replaced joint and the risk of dislocation is higher. There are certain positions for posterior approach hip replacement patients to avoid being in while they heal to reduce the risk of a dislocation. The precautions include not bending at the waist more than 90 degrees while keeping your knees together and rotating your feet out. Anterior approach hip replacement patients do not have any precautions.
Robotic surgery is new technology that allows surgeons to be more accurate in executing the personalized plan made for each patient. Before surgery, the surgeon will get a virtual 3D model of your specific hip or knee joint and will plan for the exact sizes and positions of all of your implants. On the day of surgery, the surgeon will use the robot to execute the exact plan down to the millimeter. Ideally, the advanced preparation makes the actual surgery very routine with no excitement. Accuracy has significantly improved with the technology as well.
Newer materials such as ceramics for the ball part of the hip joint have replaced older materials such as all-metal implants. The newer materials wear out slower than the older materials did, so the implants last longer.
Narcotics used to be the only method of pain management. If you had less pain you used fewer pills; if you had more pain, you used more pills. This approach left patients with a lot of pain and could lead to narcotic dependency. Now, I use a multi-modal pain management protocol which involves several different types of medications that act together to keep your pain level low so the need for narcotics is minimized.
Spinal anesthesia is used more commonly, which is better for pain control and means less general anesthesia is used. Less general anesthesia makes it easier for the patient to wake up and become alert, which is important as an important step in recovery is walking soon after surgery.
In the past, incisions were closed with large stitches or staples. Now, there are many different ways to close incisions, some of which will produce better cosmetic results. I mainly use dissolvable stitches done under the skin, which do not need to be removed. I use a skin glue to seal the skin and apply a water-resistant dressing on top, which allows you to start showering right away, although baths and the pool take more time.
In the past, patients would stay at the hospital for several days and then go to a nursing home before going home. Nowadays, many patients have joint replacements done outpatient, which means that surgery can be done at an outpatient surgery center without needing to go to the hospital and can go home the same day.
Frequently Asked Questions
Is there an age limit for hip and knee replacements?
No, there is not. I have performed a hip replacement on a 19-year-old and on a 96-year-old. However, poor health makes surgery riskier. If you have multiple other medical problems, such as heart or lung issues, diabetes, chronic wounds, etc., your surgeon will work with your primary care doctor or your other specialists to make sure you’re in a place where the surgery can be successful.
Do you decide to do a total knee replacement or a partial knee replacement before surgery?
If someone has very limited arthritis in their knee, we can start surgery with a plan for a partial knee replacement. However, I do not want to be in the operating room without the ability to do a total knee replacement if the need is there. If during surgery I encounter more arthritis than expected and a partial knee replacement is no longer the best choice, I will do a total knee replacement. I will talk to the patient in advance about the possibility of a total knee replacement depending on what I find during surgery. However, this situation, where we thought we would do a partial knee replacement and do a total knee replacement, has only happened once during my practice.
How do hip replacements and labral tears intersect?
A hip replacement is not the correct treatment for just a labral tear. If someone has arthritis in their hip and a labral tear, a hip replacement may be the correct treatment. The labrum is routinely removed during a hip replacement, so a torn labrum is not a problem when doing a replacement.
Do you recommend using a continuous motion machine after knee surgery?
No, I don’t. The continuous passive motion (CPM) machine has fallen out of favor. In the past, they were routinely used after knee replacement. Patients would lay in bed, put their leg int the machine and the expectation was that the machine would help restore their movement and strength. However, we discovered that it is the muscle activation, or the patient actively thinking and choosing to move their muscles, that improves strength and range of motion in the knee. The CPM machine doesn’t produce as good results.
Can you kneel after a knee replacement?
Yes, you can. The thinking used to be that straight line incisions on the knee had a positive psychological effect on patients, with the idea that the knee was straightened out. Unfortunately, a straight line incision over the middle of the kneecap is exactly where patients would kneel. Since the straight incision can cause discomfort, I curve the incision towards the inside part of the kneecap to reduce sensitivity and make kneeling easier.
Do Baker cysts go away after a knee replacement?
Arthritis in the knee can make the knee more inflamed and irritated which produces more fluid. The fluid escapes out to the back of the knee and into the calf area and collects in a Baker cyst. After a joint replacement, because there’s no more arthritis and bone rubbing on bone, the production of fluid will slow down and eventually the Baker cyst will disappear.