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Orthopedists should advise patients who are obese about high risk of complications with TJR
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In 2014, worldwide obesity had more than doubled since 1980, with more than 600 million adults diagnosed as obese and more than 1.9 billion adults diagnosed as overweight, according to a report from the WHO. Along with cardiovascular disease, diabetes and some cancers, a high BMI may lead to musculoskeletal disorders, such as osteoarthritis.
“We know there is a general correlation of increasing degrees of obesity and major risk factors for a number of chronic diseases and musculoskeletal disorders, especially [osteoarthritis] OA of the knee,” David J. Kolessar, MD, chief of adult hip reconstruction at Geisinger Health System, told Orthopedics Today. “Population-based studies have consistently shown that the risk of knee OA progressively rises in patients with an increasing BMI. This is related to the greater mechanical forces experienced across the joint surface. Considering the increasing obesity trend in society and the worldwide epidemic, we expect to see an increase in musculoskeletal disorders, specifically OA of the knee.”
However, Kolessar also noted BMI “should be considered a rough guide to classify obesity.”
Image: Lewis J
“BMI does not distinguish between weights associated with muscle versus fat,” he said. “BMI does not correspond to percentage of body fat or distribution of body fat among individuals, nor does it allow for gender differences.”
The American Academy of Orthopaedic Surgeons (AAOS) noted patients who are overweight or obese, which is defined by the WHO as a BMI of greater than or equal to 25 and a BMI of greater than or equal to 30, respectively, may experience a higher rate of complications when undergoing total joint replacement (TJR). To help with treatment decisions, the AAOS has surgical and nonsurgical clinical practice guidelines for the treatment of OA of the knee, with clinical practice guidelines for treatment of OA of the hip forthcoming.
“Both guidelines [are used] as a [best] practice for surgeons to have their patients lose weight as nonsurgical treatment for arthritis of the knee and, subsequently, to optimize patients prior to offering them surgery,” Brian J. McGrory, MD, editor at Arthroplasty Today and clinical professor at Tufts University School of Medicine, told Orthopedics Today.
Nonoperative treatment
Prior to surgery, patients who are obese should be treated nonoperatively to either improve their condition or to help prepare them for upcoming surgical intervention. The use of ambulatory assist devices, such as canes or walkers, can be beneficial to patients by reducing joint reaction forces affecting the arthritic joint, according to Brian M. Curtin, MD, of OrthoCarolina Hip and Knee Center.
“For knee arthritis patients, bracing can sometimes be helpful to better align the knee. A strengthening program for both hip and knee, where [patients] strengthen their muscles, [can] act as a shock absorber when the patient is performing activities of daily living,” McGrory said.
Anti-inflammatory medicines can also be helpful if the patient can safely take these, McGrory added, as well as acetaminophen and intra-articular corticosteroid injections from time to time. However, Kolessar said medication prescribed to treat arthritic joint pain should be non-narcotic.
“Narcotics are inappropriate to treat chronic arthritis pain and can create narcotic dependence problems,” he said.
The AAOS recommends weight loss as a nonoperative treatment for patients with a BMI of 25 or greater and for patients with symptomatic OA of the knee, which McGrory noted can be done by increasing the patient’s metabolism without increasing caloric intake and by having the patient participate in non-impact activities, such as riding a stationary bike or using an elliptical trainer.
Importance of weight loss
In addition to being used as a nonoperative treatment, weight loss can be beneficial once surgery is required, according to the AAOS.
“Many surgeons use a BMI cut-off for patients who receive a hip or knee replacement as BMI is often seen as a surrogate for other medical problems commonly associated with obesity,” Curtin said. “Occasionally, you get that patient with a BMI of 45 who has no other medical problems, but that is far and few between. Elevated BMI is often co-existent with metabolic syndrome, diabetes, hyperlipidemia, hypertension, [and] sleep apnea; these are all things that are concerning in the perioperative period.”
A literature review published in 2013 by a workgroup of the American Association of Hip and Knee Surgeons (AAHKS) evidence-based committee showed that as the complication profile increased, the functional improvement either decreased or occurred more gradually, despite similar satisfaction rates, between obese and non-obese patients. The workgroup also concluded patients with a BMI of greater than 30 were at risk for increased perioperative complications after total joint arthroplasty (TJA), while patients with a BMI of greater than 40 or greater than 50 had complication profiles that may outweigh the functional benefits of TJA. Physicians should counsel these patients on these risks prior to surgical intervention.
“Generally speaking, the literature has shown a higher trending complication rate in patients with a BMI [of 40 or greater] following [total knee arthroplasty] TKA and [total hip arthroplasty] THA surgery,” Kolessar said. “This data is more consistent in TKA than THA literature.”
Kolessar noted patients should be provided realistic weight loss targets at regular follow-up intervals and be reminded of their overall body weight loss goal. Those patients committed to improving their situation frequently meet their goals.
“What I found is that when you get these patients engaged in the process, they seem to do better if you plan follow-ups on a regular interval time frame with realistic [weight loss] goals they can meet,” he said.
Along with working with patients in terms of diet and exercise, Curtin said some surgeons may recommend patients with a BMI of greater than 45 be evaluated for bariatric surgery. However, there is no clear evidence a patient who undergoes bariatric surgery will have improved outcomes after TJA, so Kolessar recommends patients focus on a self-engaged weight loss program with proper oversight from their surgeon, nutritionist, dietician and therapist.
“There are studies that suggest revision or reoperation rates are no better in patients who have undergone bariatric surgery, and there is suspicion that malabsorption situations or poor nutrition after the surgery may play a role,” Kolessar said.
The topic of weight loss in patients who are obese prior to TJR is controversial as patients will have complications regardless of whether they lose weight, according to Carlos J. Lavernia, MD, clinical voluntary professor at the University of Miami. However, Lavernia told Orthopedics Today that making patients lose weight is a good way to gauge their compliance after surgery.
Surgical treatment
Once patients who are obese have exhausted nonoperative options to treat arthritis, surgical intervention is then considered along with options for the best course of action.
“If someone is obese, we are not saying that is their fault and they cannot have surgery,” McGrory said. “What we are saying is that is a medical problem that needs to be optimized because if you do not optimize it, then you have a higher risk at the time of surgery.”
Before surgical intervention, surgeons should make sure patients are aware of the long-term ramifications of an implant wearing out or becoming loose early and needing to be replaced, McGrory said.
“Patients often put more force on the joint replacement and, in the short term, that can lead to a dislocation of the joint where it comes out of place,” McGrory said. “In the longer term, that can lead to fracture or failure or wearing out of the prosthesis at an early point.”
According to Lavernia, surgeons should also make sure patients are nutritionally optimized in the preoperative period.
“Even though these patients are obese, they may be malnourished,” Lavernia said. “A thorough assessment of their nutritional status needs to be done. Normally, what we do in my unit is we check the albumin, transferrin, total lymphocyte count and vitamin D.”
“In the setting of the large patient, proper visualization is critical for optimal component positioning, which may necessitate a larger incision,” Kolessar said.
However, he added that larger incisions can lead to additional blood loss and longer operative time.
Lavernia noted that surgeons need to be careful intraoperatively because the ligaments in patients who are obese can easily rip, which may be difficult to avoid due to the thickness of the tissue and the large retraction. He added surgeons should have a backup condylar constrained knee device in case problems during knee replacement arise, and he suggested the use of a larger head during hip replacement to prevent dislocation during extreme motion.
Patients who are obese also have an increased risk for surgical site infection (SSI), which can be prevented with the use of a soap made of chlorhexidine prior to surgery, according to Wayne M. Goldstein, MD, chairman of the Department of Orthopedic Surgery at Advocate Lutheran General Hospital and professor of clinical orthopedics at the College of Medicine, University of Illinois at Chicago.
Curtin noted the risk of a SSI may be reduced by leaving the wound dressing on for at least 10 days after surgery to protect the wound longer, as well as making sure blood sugars are controlled, especially in patients with diabetes.
According to Goldstein, he uses a silver impregnated dressing (Ag Extra, Aquacel). In patients who show no drainage after 7 days, he removes the Ag Extra silver dressing and switches them to a dry sterile dressing. While dressing the wound can prevent infection, its healing can be affected by the patient’s diet.
“When dieting with absolute starvation, an obese patient can actually be malnourished and have low serum albumin below 3 g/dL. This will put them at risk of infection or lack of wound healing,” Goldstein said.
Along with preventing blood clots and pulmonary embolism by early mobilization, sequential compression devices, chemoprophylaxis, proper skin care and prevention of pressure decubitus sores is essential among obese patients, Goldstein added.
“When [patients] come up from the recovery room, [a] physical therapist or a team of nurses will have them start walking that day, [which can] prevent blood clots,” Goldstein said. “We also have special beds in our hospital that will prevent [patients] from getting bed sores.”
McGrory noted obese patients have more drainage postoperatively, as well as an impaired healing process from an increase in fatty tissue that breaks down after surgery.
“After the surgery, the wounds are scary,” Lavernia said. “[Surgeons] have to make sure [they are] aggressive with a drain. [They] need to go in and make sure [the patient does] not [have an] infection, and [if there is an infection, the surgeon needs to] clean them out.”
Fat necrosis “looks like an infection where the fat underneath the skin dies and the patient presents with a pocket of not so pretty-looking fluid, and doctors get fooled into thinking they have an infection,” Lavernia said. “Experience is critical on that because, if you have seen it before, it will not bite you.”
Postoperatively, surgeons should continue to encourage patients to lose weight and maintain an active lifestyle, according to Kolessar.
“Late challenges may include encouraging [patients] to maintain whatever successful weight loss they have achieved by upholding a more active lifestyle and continuing better dietary habits rather than returning to poor health behaviors,” Kolessar said.
The challenges and complications of TJR in obese patients vary from patient to patient depending on how patients carry their weight, according to Curtin. He noted while patients who have relatively thin legs and carry their weight in the truncal region may not be difficult from the orthopedics side of the surgery, their surgery may be difficult in terms of anesthesia.
“Patients who carry all of their weight in the truncal region and have thin legs may be at more risk than patients who carry their weight everywhere because they are typically going to present with metabolic syndrome, which is a list of things: hypertension, hyperlipidemia, central obesity, etc. These things place them at higher risk,” Curtin said. “Even though their leg might be easier to operate on, they might medically be at a higher risk than the patient with global obesity.”
Surgeon considerations
Along with the challenges patients experience, surgeons and staff can also experience challenges during the procedure. According to Goldstein, when operating on patients who are obese, surgeons should be equipped with enough staff on their team to lift and move the patient onto the operating table, as well to help hold up the patient’s leg during total hip replacement.
“The other challenge is being able to find the hip down below, which could be a foot below the skin instead of an inch or 2 [inches] below the skin,” Goldstein said.
McGrory noted surgeons may need to use specialized equipment, such as those that can hold a greater weight, when operating on patients who are obese.
“There is a physical aspect of our job doing hip and knee replacements where you have to manipulate the bones and soft tissues and that can be physically taxing on the team, the surgeon and the assistants,” McGrory said.
Overall, orthopedic surgeons should proceed with caution when performing total joint replacement on patients who are obese, according to Curtin, while Lavernia said only orthopedic surgeons who have extensive experience should perform this surgery on patients who are obese due to the high complication rate and other difficulties.
“The first, most fundamental principle in caring for these patients is that [the surgery should be performed] by an expert with experience with these kinds of patients,” he said. “They are difficult to [perform surgery on], and they are difficult to manage after surgery.”
Lavernia also noted orthopedic surgeons should include the patient in the TJR decision-making process and stress the problems that may occur. Therefore, patients will be aware of the complication rates. Kolessar added physicians should coach patients throughout the treatment and convey a sense of understanding and empathy.
“Body weight is a delicate subject to address with patients,” Kolessar said. “A sympathetic discussion regarding patients’ pain from their diseased or arthritic joint condition needs to occur. But, addressing modifiable risk factors, specifically morbid obesity, is essential.” – by Casey Tingle
- References:
- Obesity and overweight. Available at: www.who.int/mediacentre/factsheets/fs311/en/. Accessed Dec. 16, 2016.
- Obesity, weight loss and joint replacement surgery. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=A00745. Accessed Dec. 8, 2016.
- Springer BD, et al. J Arthroplasty. 2013;doi:10.1016/j.arth.2013.02.011.
- Surgical management of osteoarthritis of the knee. Available at: www.orthoguidelines.org/topic?id=1019. Accessed Dec. 9, 2016.
- Treatment of osteoarthritis of the knee (2nd edition). Available at: www.orthoguidelines.or g/topic?id=1005. Accessed Dec. 9, 2016.
- For more information:
- Brian M. Curtin, MD, can be reached at 2001 Vail Ave., #200, Charlotte, NC 28207; email: brian.curtin@orthocarolina.com.
- Wayne M. Goldstein, MD, can be reached at 9000 Waukegan Rd., #200, Morton Grove, IL 60053; email: jmcarey@uic.edu.
- David J. Kolessar, MD, can be reached at 1000 E. Mountain Blvd., Wilkes-Barre, PA 18711; email: wkwilson@geisinger.edu.
- Carlos J. Lavernia, MD, can be reached at P.O. Box 14-1028 Coral Gables, FL 33114; email: cindy@drlavernia.com.
- Brian J. McGrory, MD, can be reached at 5 Bucknam Rd., Falmouth, ME 04105; email: mcgrob1@mmc.org.
Disclosures: Goldstein reports he receives royalties from Smith & Nephew and DePuy Synthes. McGrory reports he is a consultant for Smith & Nephew. Curtin, Kolessar and Lavernia report no relevant financial disclosures.
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