Taking Aim at Knee Pain: Read Ann's Story
Date: 8/12/2016
Robotic arm-assisted partial knee replacement takes precision to another level


“Bad knees.”

We all know someone who has used this term to describe a problem deep inside the knee joint causing pain and immobility. Many of these individuals turn to everything from ice and over the counter pain medication, to physical therapy and injections to help ease symptoms non-surgically. Alas, for some, eventually the pain is too great to control and the surgeon recommends knee surgery—often knee replacement surgery.

What you may not know is total knee replacement is not the only option for those “bad knees.” Partial knee replacement can provide someone who fits the criteria with an opportunity to keep the majority of their own joint intact, making the result feel more like their natural knee than a total replacement would. 

Why Partial?
When Ann met with Michael Ast, MD, orthopedic surgeon and medical director of the Robotic Joint Replacement Program, she suspected a partial knee replacement was in her future. 

“I’d had a partial knee surgery eight years prior on my other knee and this pain was very similar,” explains Ann. “I was not looking forward to going through it again, but my knee was bone on bone. It was very painful.”

According to Dr. Ast, there is certain criteria a candidate for partial knee replacement will meet:

1. The person experiences pain in one specific area of the knee
2. The x-ray shows arthritis in that same area
3. There is no evidence of arthritis in the rest of the knee

“In general, about 5-to-10 percent of patients who need knee replacement may be a candidate for partial knee replacement,” he says.

The knee joint is a complex structure comprised of three compartments connected by ligaments and tendons. These compartments are broken down into the following areas:

Medial compartment (inside)
Lateral compartment (outside)
Patellofemoral compartment (under the knee cap)

“With a partial knee replacement, the compartment that has arthritis is replaced, and the remaining compartments of the knee are left in their natural state.  Also, the ACL (anterior cruciate ligament) and PCL (posterior cruciate ligament), which are usually removed and replaced during a total knee replacement, are preserved in their normal positions, which gives the potential for a more normal feeling knee,” explains Dr. Ast.

Natural, by Way of Technology
Ann, who spent her youth as a gymnast and cheerleader, thought she knew what to expect with partial knee replacement surgery. What she didn’t know is that in the eight years since her previous partial knee surgery, a lot had changed. 

“Dr. Ast explained to me that partial knee surgery had become a much more precise surgery. He told me he could even do it robotically now, which would help to make the fit as close to natural as possible,” she says. 

Robotic technology made its way into operating rooms years ago, but only in recent years had the technology advanced to include orthopedic surgery. The benefits of robotic-assisted surgery are mainly about precision – a key element for successful orthopedic surgery.

“In partial knee replacement in particular, the ability of the robotic technology to measure the alignment of the leg and the balance of the ligaments during surgery allows for a level of personalization that was previously unattainable,” Dr. Ast explains. 

“By having the precise measurements during surgery, the surgeon can try to ensure the implant is placed in the best position for that patient based on his/her specific anatomy, and the condition and position of their normal ligaments.  These all likely factor into the function and long term success of the surgery.”

A New Experience
“Dr. Ast instilled me with a lot of confidence going into surgery, but I was nervous,” admits Ann. 

“With my last partial knee replacement, I was in the hospital for three days. With this one, I had surgery in the morning, and I went home that evening—walking, with the help of a walker,” says Ann. “What a difference!”

This is no surprise to Dr. Ast, who has seen many patients experience a better recovery following robotic surgery. He says that while recovery is mostly related to pain control and physical therapy after surgery, the precision of robotic-assisted surgery can put a patient at an advantage.

“The potential advantage of robotic-assisted surgery in terms of recovery is that if the implant is placed in the best possible position, and the ligaments are balanced appropriately, the knee will feel more normal after surgery. This can make rehab and recovery easier for the patient.”

For Ann, the surgery was nothing like what she expected it would be—and that’s a good thing. 

“PT had me up and moving right away. I didn’t think I could do it, and I was taken aback by how easily I could move,” she recalls. 


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