Approximately 800,000 total knee arthroplasties and 450,000 total hip arthroplasties are performed annually in the United States. These procedures provide significant pain relief and restore function in patients with advanced osteoarthritis, rheumatoid arthritis, and other degenerative joint conditions. Patient evaluation before surgery includes a history, physical examination, laboratory tests, and imaging. After surgery, the rapid recovery protocol typically is used. This involves early mobilization of the replaced joint with ambulation as soon as 4 to 8 hours after surgery. Postoperative analgesia may include nerve block local infiltration anesthesia within the first 24 hours, along with opioids, cyclooxygenase-2 selective inhibitors, and acetaminophen. Periprosthetic joint infections are the primary reason for revision arthroplasty; they occur in 1% to 2% of patients. Risk factors include obesity, diabetes, poor nutritional status, and smoking. Routine use of anticoagulants has decreased the postoperative rate of venous thromboembolism. Rehabilitation includes stretching, muscle strengthening, and exercises to increase range of motion and improve gait, balance, and neuromuscular function. This can be performed in an in- or outpatient setting. In the postoperative period, most patients can resume a majority of daily activities within 6 weeks. After 3 months, most patients are functioning at 90% capacity, with full recovery by 1 year.

Case 2. KG is a 60-year-old patient with a history of hypertension, gastroesophageal reflux disease, obesity, and osteoarthritis. She has a 5-year history of bilateral low back pain with right-sided sciatica and worsening pain with ambulation. You previously ordered a radiograph of the lumbosacral spine and prescribed physical therapy for 6 weeks. Today, there is no resolution of the low back pain and noted worsening of right-sided low back pain, groin pain, and right buttock pain, resulting in a severe limp and antalgic gait. KG is unable to walk more than 100 feet without stopping due to pain. You order radiographs of the hip, which show severe osteoarthritis in the right hip with almost complete loss of joint space and sclerosing changes of the bone.