The knee is the largest and one of the most complex joints of the body. It is also a frequent site of arthritis and injury. Significant knee damage can lead to chronic pain and loss of mobility. According to the American Academy of Orthopaedic Surgeons, more than 580,000 Americans opt for knee replacement surgery each year to address irreparable knee damage. Most knee replacements prove successful, but serious complications may develop for a small proportion of people undergoing the procedure.
Infection
Deep tissue infection at the site of the knee replacement occurs in approximately 1 to 2 percent of patients undergoing the procedure, report Drs. David Jacofsky and Mark Campbell in a 2006 article published in the journal "Hospital Physician." Infection most commonly occurs during the first three months after surgery. Factors that increase the risk for this serious complication of knee replacement surgery include obesity, diabetes mellitus, low blood potassium, urinary tract infection, smoking, poor nutrition, use of immunosuppressant medications and operative time longer than 2.5 hours.
In a 2009 article published in "The New England Journal of Medicine," Drs. Jose Del Pozo and Robin Patel note that treatment of an infected knee prosthesis generally involves removal and replacement of the infected joint replacement and intensive antibiotic therapy. Common symptoms of knee prosthesis infection include pain, loosening of the joint, swelling and fever. Among patients with a low-grade infection, pain and gradually diminishing joint function may be the only presenting symptoms.
Deep Venous Thrombosis
Blood clot formation in the deep veins of the legs, also known as deep venous thrombosis, remains a significant complication of knee replacement surgery. Many deep venous thrombi, or DVTs, are asymptomatic and clear without medical consequence. A small number of DVTs, however, may cause symptoms and pose a risk of breaking off and traveling to the lungs.
In a 2009 article published in "The New England Journal of Medicine," Dr. Michael Lassen and colleagues report that asymptomatic, clinically silent DVTs occur in approximately 30 to 40 percent of patients undergoing knee replacement surgery. Within 30 days of surgery, however, approximately 2 to 4 percent develop symptomatic DVT. Walking soon after surgery and adherence to medical and physical treatments to prevent the formation of DVT can reduce the risk of this potentially serious complication of knee replacement surgery.
Knee Stiffness
Some people undergoing knee replacement surgery experience knee stiffness, characterized by limited range of motion and persistent pain with the prosthesis. In a 2009 article published in the "Journal of Orthopaedics and Traumatology," Dr. Alfredo Panni and colleagues report that risk factors for knee stiffness after replacement surgery include substantially decreased knee range of motion prior to surgery, smoking, and previous surgery on the knee. Surgical errors in the positioning of the prosthesis can also lead to postoperative knee stiffness.
References
- American Academy of Orthopaedic Surgeons: Total Knee Replacement
- "Hospital Physician"; The Infected Total Knee Arthroplasty Part 1: Identification and Diagnosis in the Primary Care Setting; David J. Jacofsky, M.D., Mark D. Campbell, M.D.; January 2006
- "The New England Journal of Medicine"; Infection Associated with Prosthetic Joints Jose L. Del Pozo, M.D., Ph.D., Robin Patel, M.D.; August 2009
- "The New England Journal of Medicine"; Apixaban or Enoxaparin for Thromboprophylaxis after Knee Replacement; Michael Rud Lassen, M.D., et al.; August 2009
- "Journal of Orthopaedics and Traumatology"; Stiffness in Total Knee Arthroplasty; Alfredo Schiavone Panni, M.D., et al.; September 2009
