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Joint Effort: Breakthroughs in Hip and Knee Replacement Surgery

An older man with knee and hip pain after exercising.

If you're like millions of Americans, you may be dealing with an aching hip or a couple of creaky knees, especially if you're starting to feel the effects of age.

Despite your pain and discomfort, going through a total joint replacement surgery might seem daunting—long recovery times, hospital stays, swelling and pain are nobody's idea of fun.

If you're unsure about total joint replacement surgery, there's good news: Total joint replacement has come a long way in recent years. Breakthroughs in surgery mean less pain, a faster recovery and a lot less time in the hospital so you can get back to the things you love. In many cases, you may not even need to stay overnight.



Cedars-Sinai orthopaedic surgeon Sean S. Rajaee, MD

Sean S. Rajaee, MD

"We have made so much progress in hip and knee replacements that 60%-70% of our patients can go through the process as outpatients," says Dr. Sean S. Rajaee, a board-certified orthopaedic surgeon and co-director of the Outpatient Hip and Knee Center at Cedars-Sinai. "People who come and see us are thrilled to learn that we can use minimally invasive techniques, and that they'll be home and up and about much sooner than they thought."

The goal of total joint replacement is not to switch out your entire knee or hip. It's to relieve pain and improve mobility by replacing the hip or knee joint with an implant or "prosthesis."

The traditional approach uses a very long, open dissection to view and access the joint. Minimally invasive surgery uses smaller dissections, causing much less soft-tissue trauma.

"The technique also requires less cutting of the tendons and ligaments, which means we don't need to transect muscle to get to the joint," Dr. Rajaee explains. The result is less post-surgery pain and speedier healing.

Another breakthrough may be making an even bigger difference.

"We've had major developments in analgesia and anesthesia techniques," Dr. Rajaee says, referring to peri-articular injections—a mix of medications that help with pain and swelling—and regional nerve blocks provided by anesthesiologists, which reduce the need for post-op narcotics that cause drowsiness and other adverse effects.


"We use a personalized approach, and while most of our patients do walk within hours of the procedure, we are careful to find the right timeline for each individual."


"Both of these techniques are significant advances that help people heal with less discomfort," he adds.

Minimally invasive surgery and analgesia aren't the only reasons hip and knee replacements have improved. Cedars-Sinai is at the forefront of intraoperative imaging, which provides images of the surgical area in real time, allowing the surgeon to see exactly where the implant is and to make small adjustments that can have a big impact on the outcome. That's because the position of the implant is the most important factor in ensuring long-term success.

"If we place the implant perfectly, we maximize the odds that our patient will have excellent results," Dr. Rajaee says. To obtain the most precise implant positioning, Cedars-Sinai is also a pioneer in robotic-assisted surgery, especially for knee replacements.



Dr. Rajaee, a leader in studying technologies in total joint arthroplasty, already performs most of his knee procedures with robotic assistance. Preoperative robotic software helps plan precisely how much bone should be removed and where an implant should be placed

During surgery, the robotic arm ensures that this plan is followed exactly. The technology can help the surgeon achieve the optimal alignment for the artificial joint, which can improve stability and mobility.



Because of these advances, the Outpatient Center has a motto: Up in Three.

"We use that phrase because we can get most patients walking within three hours after surgery," Dr. Rajaee explains, while stressing that every case is different and that it's important not to push a patient just to meet a predetermined goal. "We use a personalized approach, and while most of our patients walk within hours of the procedure, we are careful to find the right timeline for each individual."

That personalized approach also means figuring out which patients will do better with standard surgery and a longer stay at the hospital.



"Not everyone is a good candidate for an outpatient procedure, but it's a myth that only younger people can use that approach," Dr. Rajaee says. "We have many outpatients in their 80s and 90s, although it helps to be in good health and free of serious medical conditions.

"Safety is always paramount, so if we think it's better for you to be admitted as an inpatient, that's what we'll recommend. My goal is always to do what's right for each individual patient, striving for the best possible outcome in every case."