HSHS Medical Group offers the latest partial knee replacement procedure to address the growing demand of once-active patients in their 40s, 50s, and 60s, enabling a faster return to their active lifestyle. In many cases, the partial knee replacement can have patients back to enjoying a more energetic and pain-free lifestyle with improved mobility in weeks, not months.
According to the American Academy of Orthopaedic Surgeons, the knee is the largest joint in the body, and one of the most easily injured. In addition, conditions such as knee osteoarthritis can cause significant pain and discomfort that can become debilitating and compromise lifestyle. During knee replacement surgery, damaged bone and cartilage are removed and resurfaced with metal and plastic components. In partial knee replacement (also called “unicondylar” knee replacement, or UKR), only a portion of the knee is resurfaced. This procedure is an alternative to total knee replacement for patients whose injury is limited to just one area of the knee1.
“When you look at the knee replacement portion of my practice, I perform three or four partial knee replacements to every total knee replacement. This is the opposite of 15 years ago,” said Donald Weimer, MD, a board-certified orthopedic surgeon with HSHS Medical Group’s Orthopedic & Sports Medicine practice in O’Fallon, Illinois.
Dr. Weimer attributes this to a fast-growing patient population who wants to remain active, but is limited as a result of severe arthritis. “They don’t want a total knee replacement and they have had to really slow down their activity level. In addition, they will not have the longer recovery time that a total knee replacement can require.”
The process starts with a visit to the doctor’s office for an assessment and a full patient workup, which helps identify any preexisting medical conditions. This may include consulting with the patient’s cardiologist or pulmonologist (if the patient has one) to determine if the patient can undergo general anesthesia or spinal anesthesia. “We review the risks and benefits to decide if UKR is the correct operation for the patient,” explains Dr. Weimer.
According to Dr. Weimer, “Most candidates for a partial knee replacement are experiencing severe bone-on-bone arthritis and have not responded to conservative options, such as anti-inflammatory medicines, injections, or physical therapy. For most candidates, pain is most often isolated to the medial (inside of the knee) or lateral (outside of the knee) compartment. The good news for patients who thought they may have needed a total knee replacement is that most are candidates for a partial knee replacement.”
Following surgery, the therapists have patients up and walking quickly, usually by the afternoon. Two to four weeks of physical rehabilitation follows. “A typical outcome is when a patient presents for follow-up at two weeks with minimal pain, improved joint mobility, and they don’t need to hold on to anything else to walk—cane, walker, crutches,” says Dr. Weimer.
The benefits to the patient can be significant and include rapid relief of pain and a shorter recovery time. In addition to minimal blood loss, there are lower incidences of risks such as infection or blood clots. The patients’ families enjoy the access to care for their loved one here at home and no longer need to worry about taking off work or leaving the area for care.
Bill Palmer, one of Dr. Weimer’s recent patients, describes his return to a more active lifestyle.
“I had been experiencing pain on the inside portion of my left knee, especially when I was up and walking,” explained Bill. “If I stood for very long, I had significant pain. It got to the point where walking any distance or even standing was difficult, and I would sit every time I had the chance.”
Although he was in unbearable pain, Bill, a physical therapist, continued to see patients at his practice in southern Missouri. “I would sit on a stool and roll myself around from patient to patient. One therapist commented, ‘Your patients walk better than you do!’ At that point, I decided I didn’t want to miss any more time with my family, friends, and patients.” Bill made an appointment to see Dr. Weimer. Together they determined that partial knee replacements were the best course of action.
“Now, the pain that I had before is gone,” Bill declared enthusiastically. “My energy level has improved, too. I have more mobility, less pain, and my range of motion is already improved. I’m looking forward to fishing and playing catch with the grandchildren. I can’t wait to walk in to their school with them on Grandparents Day. Now I will be able to do that pain free!”
Dr. Weimer concludes, “Post-surgery patients can typically perform activities at a higher level. Many are back and enjoying their favorite activities such as swimming, golfing, biking, or more time with the grandkids. Now they have access to care here at home and the opportunity to return to a fuller and richer life.”
Patients can find out if partial knee replacement is an option by calling Dr. Weimer’s office at 618-622-0155. A referral is not necessary and most insurance is accepted.


1American Academy of Orthopaedic Surgeons. Unicompartmental Knee Replacement (Partial Knee Replacement). Accessed 10/13/2016.

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