Total Knee Replacement in the Very Elderly
Osteoarthritis is one of the most prevalent chronic, disabling diseases and affects two-thirds of individuals >65 years of age. More than 10 million Americans have osteoarthritis. Joint replacement is the preferred treatment for alleviating pain and improving function in patients with advanced osteoarthritis.1-3 The following case illustrates a number of issues faced by a frail elderly patient pursuing total knee replacement (TKR).
Mr. X, a 92-year-old man with a history of severe arthritis of the left knee, was hospitalized for a mechanical fall and severe pain in his left knee. His medical history included congestive heart failure (CHF), degenerative joint disease of both knees, hypertension, cirrhosis, pseudogout, atrial fibrillation, interstitial lung disease, s/p pacemaker, and chronic obstructive pulmonary disease (COPD) necessitating home oxygen. He had had recurrent hospitalizations for mechanical falls and severe knee pain.
At the time of presentation, the patient, who had never married and was childless, lived alone in a trailer and acknowledged being an alcoholic and a smoker. During his hospitalization, he was given an intra-articular injection of cortisone into his knees and lidoderm patches for pain relief. The surgical option of knee replacement was not offered to the patient because he was considered to be at high risk for an operative intervention. He was transferred to a skilled nursing facility for physical rehabilitation.
During his nursing home stay, he actively participated in rehabilitation activities, but he was unable to walk because of the knee pain. An intra-articular corticosteroid injection, a lidoderm patch, and analgesics were unsatisfactory at relieving his pain. His functional capacity and medical condition improved to where he could get around in a wheelchair and walk a few steps. He no longer required supplemental oxygen. At that point, Mr. X told his physician that he wanted to undergo a knee replacement, reportedly saying, “If I can’t walk, I’d rather be dead.”
Mr. X was reevaluated by the orthopedic surgeon for a knee replacement. Preoperative evaluation included an echocardiogram, which showed an ejection fraction of 40%, and pulmonary function tests, which showed a combination of restrictive and obstructive disease, with the patient having a forced expiratory volume in 1 second (FEV1) of 2.15 L. His serum albumin level was <3.5 g/dL. His advanced age, serum albumin level, and history of CHF and COPD placed him in the high-risk surgical category. Mr. X was counseled about the risks but decided to proceed with the operation.
The patient underwent an elective left TKR. During the postoperative period, he developed anasarca, jaundice (peak bilirubin level, 4.2 mg/dL), and acute renal failure. He also developed a deep vein thrombosis in the left leg and a sacral ulcer during hospitalization. The jaundice and acute renal failure resolved, and he was discharged back to the nursing home in stable condition.
At the nursing home, the patient refused to participate in physical therapy and was eating poorly. He was seen by a psychiatrist and started on an antidepressant for subclinical depression. Mr. X continued to deteriorate and died 2 months after the surgery. A combination of his comorbid factors, the remaining osteoarthritis in his other knee, his inability to participate in rehabilitation, and his lack of social support likely contributed to the adverse outcome.
Osteoarthritis causes debilitating pain and impairs mobility.4 In patients with advanced disease, noninvasive treatments, such as medications and physical therapy, have limited value.4 More than 500,000 TKR procedures are performed annually in the United States, accounting for more than $11 billion in costs.3,5 As life expectancy lengthens, an increasing number of patients who reach the tenth decade of life are likely to require TKR.1,6
Primary care physicians and geriatricians play a central role in the management of patients with osteoarthritis. They are often the first to counsel patients about available treatment options and provide referrals to orthopedic specialists. Hamel and colleagues4 studied the decision-making and the clinical outcomes of joint replacement surgery in the elderly. They reported that 45% of the patients in the study had not been offered the option of TKR as a potential treatment by any physician. Providing patients with information about the risks and benefits of TKR surgery will allow them to participate more fully in making decisions about their care.
According to the 2003 National Institute of Health Consensus, 90% of patients who undergo TKR experience rapid and substantial improvement in pain, function, and quality of life.7 Short-term outcomes, as documented by functional improvements, are significantly improved. Studies suggest that surgeons and hospitals that perform a higher volume of TKR procedures have better outcomes.5,7
TKR has been described as safe and effective in elderly patients.1,8 A study by Pagnano and colleages1 involving 41 patients ≥90 years of age with multiple medical problems found that the 34 patients who underwent primary TKR experienced improvement in Knee Society pain scores, which increased from an average of 30 points preoperatively to an average of 86 points at a mean of 3.9 years of follow-up (P <.01). (Knee Society pain score is based on pain, stability, and range of motion of the joint; a score of 100 is obtained in a well-aligned knee without pain.) Improvements in function were not as significant, with Knee Society function scores going from a mean of 26 points preoperatively to a mean of 33 points at the last follow-up. Postoperatively, 76% of patients had no limp or only a slight limp and 76% were able to climb steps; in addition, 45% of patients could walk at least one block and 41% could walk indoors after the surgery. Medical complications were seen in 41% of patients, with delirium being the most common. The 40 patients who survived the operation lived a median of 4.4 (±2.2) years after their procedure and expressed high levels of satisfaction.1
Shah and associates9 conducted a retrospective review of charts and radiographs for 130 frail and elderly patients who underwent TKR (n = 30) or a total hip replacement (n = 70). Patients were ≥80 years of age at the time of the procedure, with an average age of 85 years. The average length of follow-up was 6 years. All patients had significant comorbid factors, with an American Society of Anesthesiologists (ASA) class of 3 to 4. Preoperatively, all patients required an assistive device to ambulate, whereas after joint replacement, 90% were able to walk without using an assistive device. At 5-year follow-up, 70% of those who had been household ambulators were now community walkers, 88% maintained community ambulation, and 12% could walk inside the house. Most patients (95%) selected the highest level of satisfaction with the results of their operation.9
Hawker and colleagues10 found that the absence of problems with the contralateral knee, undergoing primary knee replacement rather than revision, and receiving good social support were predictors of better physical function after the replacement procedure. A study by Desmeules and associates11 showed that patients with contralateral knee pain, higher psychological distress, high body mass index, and lower social support had worse preoperative pain and function and would benefit from preoperative rehabilitation. Interestingly, age and obesity do not seem to have a negative impact on patient-reported outcomes for postoperative pain and physical function.10
Although postoperative rehabilitation is commonly used in the management of patients who have undergone TKR, its effectiveness has not been well studied. Postoperative knee stiffness and pain are common complications after TKR surgery. Early postoperative rehabilitation focuses on reducing pain and restoring the joint’s mobility and flexibility. Flexion contracture is a common cause of postoperative pain, making active and passive knee extension a critical component of postoperative early rehabilitation.12
A randomized controlled trial conducted by Petterson and colleagues3 concluded that progressive strengthening of the quadriceps after TKR, with or without neuromuscular electrical stimulation, helped patients achieve short- and long-term functional recovery close to the functional level observed in healthy older adults. These findings were supported by Moffet and associates,13 who concluded that intensive rehabilitation improves function after TKR. Studies have also shown that there is no difference in pain and functional outcomes or patient satisfaction between individuals who receive home-based rehabilitation services and those who receive inpatient rehabilitation services.14
The increased incidence of comorbid conditions places the elderly at higher risk for perioperative complications. TKR should be considered in the very elderly after balancing the benefits of the operation against its risks. Limited data, however, are available regarding the implications of this particular surgical procedure for the very-elderly population.
The American College of Physicians’ guidelines for assessing risk for perioperative complications suggest that pulmonary complications are more likely than cardiac complications to predict long-term mortality after surgery.15 The perioperative period is considered to begin 2 to 3 months before a surgical procedure and continue until 3 months have elapsed since the surgery. Age >60 years, COPD, and CHF are independent preoperative risk factors for perioperative complications.15 Preoperative risk is increased with greater levels of functional dependence, an ASA class of ≥2, and a serum albumin level of <3.5 g/dL. All patients undergoing noncardiothoracic surgery should be evaluated for COPD and CHF, ASA score, and degree of functional dependence.