The Painful Total Knee Arthroplasty
Total knee arthroplasty is one of the most common orthopedic procedures in the United States, with approximately 1,000,000 cases performed each year. A well indicated and performed total knee arthroplasty leads to excellent results; improvement in pain, resuming previous activities, and a better quality of life. Despite this, there is still a proportion of people not satisfied after total knee arthroplasty. According to certain studies, up to 15-20% of patients are dissatisfied with their total knee replacement. Why is that?
There are several reasons a patient may not be satisfied with their total knee arthroplasty. It is important to note that some pain and discomfort after surgery is completely normal, and will improve with directed therapy and time. In some instances, there could be an issue with the implant itself or with how the knee recovered from surgery. Some reasons a patient may have residual pain or dissatisfaction after surgery could include: infection, implant loosening, instability of the implant, or stiffness.
Infection: This is a rare but serious complication that can be a cause of pain. Symptoms may include redness, warmth, swelling, drainage, fever, and sudden onset of pain. Infection can occur soon after surgery or even years later. Your work up may include a blood draw to look at specific laboratory values and an aspiration to draw fluid off of the knee to send for other specialized tests.
Aseptic loosening (implant loosening): During your initial knee replacement, your surgeon likely used bone cement or a specific implant with specialized coating to ensure the implant is bonded to the bone. Over time, the implant may become loose, leading to activity-related pain and swelling. Your doctor may order X-rays and/or other specialized scans to look for evidence of loosening.
Instability: Every knee is unique, and sometimes differences in how the implant fits or aligns with your leg can create discomfort. Pain that persists despite good healing may be related to the position of the components or with how the knee was balanced. In addition, malposition components may lead to patellar tracking issues, which can be a secondary cause of persistent pain. If this is suspected, your physician may order X-rays or special scans for further evaluation.
Arthrofibrosis (knee stiffness): In the first few months, soreness and stiffness are expected as tissues heal and muscles regain strength. Sometimes, scar tissue can build up around the joint, limiting motion and causing pain – this is called arthrofibrosis. Regular stretching, physical therapy, and maintaining movement are key to preventing stiffness in the early post operative course. In late stages, arthrofibrosis may require surgical intervention to correct.
Ultimately, total knee arthroplasty remains an excellent procedure, with some of the best outcomes out of all orthopedic procedures. Despite this, some patients may not be pleased with their knee after surgery. It may be worth seeing an orthopedic surgeon who specializes in knee replacement surgery to evaluate for causes of pain. In some instances, specific issues can be identified and there may be surgical options to help improve your knee function and pain; this is called revision total knee arthroplasty. Additionally for some cases, there are other non-operative modalities that may benefit you.
Whether seeing a surgeon for your first-time knee replacement (primary total knee arthroplasty) or for a revision, it is important to know your surgeon. In general, surgeons that are high volume in joint replacement surgery or have had additional fellowship training in hip and knee replacement tend to have fewer complications and better patient satisfaction rates. Be sure you feel comfortable with your surgeon, you feel that you have appropriate expectations regarding surgery and post op recovery, and that you are a good candidate for surgery.
