AAOS Clinical Practice Guideline: Surgical Management of Osteoarthritis of the Knee: Evidence-based Guideline

Osteoarthritis (OA) is the most common cause of disability in adults in the United States.1-4 Symptomatic OA of the knee develops in nearly one in two people by age 85 years. Currently, total knee arthroplasty (TKA) is the most common reason for inpatient hospitalization; 3 million women and 1.7 million men have undergone knee arthroplasty in the United States.5 In 2011, 757,000 knee arthroplasties were performed for arthritis. Genetic predisposition, trauma, overuse, obesity, and certain occupations increase the risk for the development of OA of the knee. The symptoms associated with OA of the knee include joint pain, stiffness, and decreased mobility. The goal of treatment is to provide symptomatic relief initially through noninvasive and nonsurgical means, including NSAIDS, weight loss, and an exercise/strengthening program.5-7 When symptoms persist and worsen despite the use of nonsurgical methods, TKA is an effective intervention to relieve pain and improve function and mobility.4,5,8 However, there are risks and benefits with any surgical intervention and these will vary depending on patient factors and comorbidities. During the preoperative, perioperative, and postoperative aspects of surgical management of OA of the knee, there are multiple decision points and options. Those options, based on the best evidence, are highlighted in the American Academy of Orthopaedic Surgeons Surgical Management of Osteoarthritis of the Knee: Evidence-Based Guideline.5 History The patient is a 67-year-old woman who reports gradually worsening diffuse left knee pain over a 3-year period. She was walking 10 miles per week until 6 months ago when she had to decrease her activity because of moderate to severe pain with weight bearing. She has a history of type 2 diabetes mellitus and has a body mass index of 33. She has no other significant past or current medical diagnoses, and she reports no history of trauma to the knee. Physical Examination Examination reveals a mild left knee effusion and increased tenderness over the medial joint line compared with the lateral joint line. Passive arc of motion of the left knee is 10° to 100° compared with 0° to 125° on the right side. The patient walks with a minimally antalgic gait on the left side without the use of an assistive device. Imaging Standing AP, lateral, and Merchant radiographic views reveal moderate to severe tricompartmental degenerative changes with loss of joint space greatest in the medial and patellofemoral compartments and osteophyte formation (Figure 1).Figure 1: AP (A), lateral (B), and Merchant view (C) radiographs demonstrating moderate to severe tricompartmental degenerative changes with loss of joint space greatest in the medial and patellofemoral compartments and osteophyte formation.Initial Management The patient started taking NSAIDS twice daily, with moderate relief of pain. She never used narcotic medications for her pain. She enrolled in a weight loss and structured physical therapy program and was able to decrease her body mass index to 28 while also strengthening her quadriceps. Good control of the diabetes mellitus was achieved and maintained. An intra-articular steroid injection provided 2 months of pain relief but the symptoms recurred, so she began to use a cane in her right hand when walking longer distances. Total Knee Arthroplasty The patient met with an orthopaedic surgeon to be evaluated for knee arthroplasty. Despite her efforts to manage the inflammation, decrease her weight, and control her diabetes, she reported more progressively painful symptoms and thus made the decision to proceed with surgical management of OA of the knee after discussion of the risks and benefits. In a shared decision-making discussion, the patient was offered the option of TKA because of the tricompartmental degenerative changes. The procedure was performed under spinal anesthesia with a supplemental adductor canal block for perioperative pain control and to minimize opiate usage. The surgeon opted not to use a thigh tourniquet during the procedure in order to maximize pain reduction and postoperative function. No drain was used in the surgical wound. Tranexamic acid was used to minimize postoperative blood loss. The implant used was a cemented, posterior stabilized design with all-polyethylene tibial and patellar components. No antibiotics were used in the cement. Neither surgical navigation nor patient-specific instrumentation was used. Postoperative Management An icepack was placed over the left knee each nursing shift to decrease swelling. A continuous passive motion machine was not used. Twice daily postoperative physical therapy with full weight bearing was initiated on the day of the surgery. She had no postoperative complications and required no blood transfusions based on a postoperative hemoglobin level of 9.6 mg/dL. She was discharged on postoperative day 3 and enrolled in an outpatient physical therapy structured exercise program 3 days per week. Outcome At 3 months postoperatively, the patient is ambulating independently without assistive devices. She requires no pain medications and is maintaining a regular self-initiated exercise program at the local gym. The arc of motion for the left knee measures 0° to 120°. She is satisfied with the outcome of the TKA. The patient had preoperative preparation with risk mitigation and rehabilitation recommended using the best evidence as outlined in the AAOS Clinical Practice Guideline: Surgical Management of Osteoarthritis of the Knee: Evidence-based Guideline.