Orthopedics Hip & Knee Print Complications and Risks of Knee Replacement Surgery By Jonathan Cluett, MD Updated May 15, 2019 Medically reviewed by a board-certified physician More in Orthopedics Hip & Knee Causes of Pain ACL Injury Kneecap (Patella) Conditions Knee Ligament Injuries Knee Replacement Surgery Meniscus Injuries Hip Injuries Hip Replacement Surgery Surgical Procedures Replacement Implants Sprains & Strains Fractures & Broken Bones Physical Therapy Orthopedic Surgery Osteoporosis Pediatric Orthopedics Sports Injuries Shoulder & Elbow Hand & Wrist Leg, Foot & Ankle Assistive Devices & Orthotics Medication & Injections View All Most patients who choose to have knee replacement surgery are very happy with their decision. Typical patients find relief of pain, and an ability to increase their activities. However, there are possible complications of surgery, and why knee replacement patients may not be happy. Here are five problems that can frustrate patients who have knee replacement. 1 Knee Stiffness Knee stiffness after replacement can often be treated with therapy. UpperCut Images / Getty Images One of the most common problems people experience after knee replacement is a stiff knee joint. Often these symptoms can cause difficulty with normal activities including going down stairs, sitting in a chair, or getting out of a car. Management of a stiff knee joint after replacement can be a challenge. The best treatment is aggressive therapy in the early stages of recovery in an attempt to avoid the stiffness from occurring. Special splints to stretch the joint are also sometimes helpful. In rare circumstances, a second surgery can be performed to allow more mobility of the knee joint. One of the most important factors that contribute to mobility after knee replacement surgery is the mobility patients had before surgery. Patients that had a stiff joint going into surgery are much more likely to end up with stiffness after surgery. Other factors can also contribute to the likelihood of developing knee joint stiffness after replacement. Stiffness After Knee Replacement 2 Clicking or Clunking P. Marazzi / Getty Images Patients are often surprised when they hear noises coming from their artificial joints. In general, noise without pain is not a problem, but your surgeon can tell you if there is something to be concerned about. Because artificial joints are made of metal and plastic, it is not uncommon to hear clicking, clunking, or popping when the knee bends back and forth. There is some concern when pain is associated with these noises. In situations where knee pain is accompanied by these noises, it is worthwhile to have your surgeon evaluate. Some unusual causes of these noises include scar tissue formation, instability of the knee joint, or loosening of the implants. Knees That Make Noise After Replacement Surgery 3 Wearing Out of Implants Knee replacement implants can wear out over time--if they do, a second knee replacement may be necessary. Peter Dazeley / Getty Images Knee implants don't last forever, but the goal should be for the knee replacement to last your lifetime. Unfortunately, not every implant lasts a patient's lifetime, and in these cases, a second knee replacement, called a revision knee replacement, may be necessary. Knee replacements are wearing out more commonly as younger, more active patients are seeking this as a treatment for their knee pain. With these patients, the stress and demands placed on a knee replacement are higher, and there is more of a chance of further surgery being necessary. There is significant controversy about what activities should be performed by patients who have a knee replacement. It is known that some strenuous activities, including impact sports, skiing, and even golf, can create stress on the implants that may lead to early failure of the implanted joint. While many patients do these activities, there is some good evidence that this may lead to faster wearing on the implanted knee joint. Sports and Activities After Knee Replacement 4 Infection Jose Luis Pelaez / Getty Images Infection after knee replacement surgery is the most feared complication of most patients and surgeons. The primary focus must be to take all precautions possible to try to avoiding infection. Even with appropriate steps, sometimes infections still occur. Knee replacement infections are generally separated into early and late infections. An early infection occurs within six weeks of the original surgery, and is typically the result of skin bacteria entering the joint at the time of surgery. Typical treatment involves surgical cleansing of the knee joint with appropriate antibiotics administered for several weeks or months. Infections that occur after six weeks from the time of surgery are called late infections. These infections typically are caused by bacteria in the bloodstream finding their way to the knee joint. These infections can be very difficult to cure, and typically require the entire knee replacement to be removed in order to fully eradicate the infection. Infection After Knee Replacement 5 Blood Clot Rolf Ritter / Getty Images Blood clots occur in the large veins of the leg and can cause pain and swelling. In unusual circumstances, the blood clot can travel from the legs through the circulatory system and to the lungs. These blood clots that move to the lungs are called a pulmonary embolism and can cause serious, even life-threatening, problems. Most patients are placed on blood thinning medications for at least several weeks after having knee replacement surgery. Blood thinners can help decrease the chance of developing a blood clot, but there is still a possibility of this occurring. How to Treat Blood Clots During and After Surgery Was this page helpful? Thanks for your feedback! Dealing with joint pain can cause major disruptions to your day. Sign up and learn how to better take care of your body. Click below and just hit send! Email Address Sign Up There was an error. Please try again. Thank you, , for signing up. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Yu S, Garvin KL, Healy WL, Pellegrini VD Jr, Iorio R. "Preventing Hospital Readmissions and Limiting the Complications Associated With Total Joint Arthroplasty" J Am Acad Orthop Surg. 2015 Nov;23(11):e60-71.