$2.3 Million NIH Grant for Exercise-After-Injury Research

Laura Arenschield

May 08, 2020

A research team at the University of California, Davis has been awarded a $2.3 million grant to try to answer a basic question about osteoarthritis after joint injury: What is the right amount of exercise to reduce inflammation and speed healing after injury?

Previous research has shown that some movement after joint injury can reduce swelling and preserve the range of motion a patient has in that joint. But too much exercise can damage the joint tissue even more and cause inflammation. Too little, though, can cause bone and muscle loss and make the joints stiff.

"We know overuse or too much exercise is bad and can make injury worse, and we know too little movement is also bad," said Blaine Christiansen, PhD, associate professor of orthopedic surgery at UC Davis, who is principal investigator for the study. "We know that somewhere in between is a good level, but no one really knows what that is right now. And that's what we're going to start investigating."

The question is one that a number of sessions were designed to address at the American Academy of Orthopaedic Surgeons 2020 Annual Meeting in Orlando, but the meeting has moved online. Cassandra Lee, MD, a coinvestigator on this study and clinical faculty in orthopedic surgery at UC Davis, had been scheduled to be part of a presentation about managing pain after anterior cruciate ligament reconstruction.

The National Institute of Arthritis and Musculoskeletal and Skin Diseases at the National Institutes of Health announced the funding in March, just before a stay-at-home order was issued in California to mitigate the spread of COVID-19. Until that order lifts, the study — award number R01AR075013 — is on hold, Christiansen reported.

"We're getting a little bit of a slow start, but we'll be working on this project for at least 5 years," he said. "Hopefully, in a couple of months we can restart without too much delay."

Experiments on Hold

The science behind the study is basic: How much loading or unloading helps a joint heal and restore its range of motion after surgery? How much hurts? What combination of rest and exercise leads to minimal — or no — osteoarthritis? Experiments haven't started yet, but the team at UC Davis plans to study injuries and look at periods of rest and activity in mice in their quest for answers.

The question at the heart of the study is an important one for physicians, physical therapists, and athletes, including weekend warriors.

Joint injuries, like anterior cruciate ligament and meniscus tears, not only keep people from physical activity, they often lead to osteoarthritis, a condition that affects an estimated 32.5 million adults in the United States, according to the Centers for Disease Control and Prevention.

"This is costing billions every year," said Jim Bradley, MD, president of the American Orthopedic Society for Sports Medicine and professor of orthopedics at the University of Pittsburgh Medical Center. "It is well worth its weight in research."

Joint injuries, which are common in youth athletes and people in their early 20s, can lead to osteoarthritis later in life. That often hits as people affected approach their mid-30s or 40s, when exercise habits are crucial to the maintenance of long-term health.

"It's a problem that is going to be more and more important as people are living longer and becoming more active," Christiansen said. "Anything you can do to maintain a healthy joint for as long as possible is beneficial."

This is the sort of basic science that can lead to paradigm shifts in the way surgeons and physical therapists treat patients with joint injury, said Bradley, who is also head team physician for the Pittsburgh Steelers.

"We need to be able to tell patients what postoperative exercises are important," he said. "I tell my patients who have these types of injuries: You used to be a Porsche, but you wrecked your car and, if you don't fix the suspension — the joint — and you race it again, what are you going to do to the tires? If you fix the suspension, you can get it closer to what it was before. You can't race on bad suspension."

The study will also investigate the effects of knee restabilization surgery in mice.

"What you do clinically to restabilize the knee after ligament surgery matters, so we're looking at how that affects the biomechanics," Christiansen said.

American Academy of Orthopaedic Surgeons (AAOS) 2020 Annual Meeting.

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