Knee and hip replacements can improve how well patients get around and can significantly increase their quality of life. But if a bone near the new joint breaks, the injury can be a major setback for the patient’s mobility, and the consequences can be life-threatening.
The proportion of patients who experience a periprosthetic fracture within 5 years of total hip arthroplasty is 0.9%. After total knee arthroplasty (TKA), the proportion is 0.6%, research shows.
Those rates might seem low. But given that more than a million of these joint replacement surgeries are performed each year in the United States – they are the most common inpatient surgical procedures among people aged 65 and older – thousands of revision surgeries due to periprosthetic fractures occur each year.
Primary care clinicians who make their patients’ bone health a priority early on – years before surgery, ideally – may help patients enjoy the benefits of new joints long term.
At the 2022 annual Santa Fe Bone Symposium this summer, Susan V. Bukata, MD, professor and chair of orthopedics at the University of California, San Diego, showed an image of “what we’re trying to avoid” – a patient with a broken bone and infection. Unfortunately, Dr. Bukata said, the patient’s clinicians had not adequately addressed her skeletal health before the injury.
“This is a complete disaster for this person who went in having a total hip to improve their function and now will probably never walk normally on that leg,” Dr. Bukata said at the meeting.
The patient eventually underwent total femur replacement. Five surgeries were required to clear the infection.
Medical and surgical advances have allowed more people – including older patients and those with other medical conditions – to undergo joint replacement surgery, including replacement of knees, hips, and shoulders.
The surgeries often are performed for adults whose bones are thinning. Sometimes surgeons don’t realize just how thin a patient’s bone is until they are operating.
Prioritizing bone health
In patients with osteoporosis, the bone surrounding the new joint is weaker than the metal of the prosthesis, and the metal can rip out of the bone, Dr. Bukata told this news organization. A periprosthetic fracture should be recognized as an osteoporotic fracture, too, although these fractures have not typically been categorized that way, she said.
People live with total joints in place for as long as 40 years, and fractures around the implants are “one of the fastest growing injuries that we are seeing in older patients,” Dr. Bukata said. “People don’t think of those as osteoporotic fractures. But a 90-year-old who falls and breaks next to their total knee, if they didn’t have that total knee in place, everybody would be, like, ‘Oh, that’s an osteoporotic fracture.’ ”
Periprosthetic fractures tend not to occur right after surgery but rather after the bone continues to lose density as the patient ages, Dr. Bukata said.