Does returning to sport after ACL injury increase the risk of knee arthritis?
For active people who are unfortunate to suffer an anterior cruciate ligament (ACL) injury to their knee, one of the first questions is “when can I return to sport?”
This is a difficult question for physiotherapists, surgeons and other healthcare provides to answer as it can depend on many factors – how much rehab is done, how quickly strength and power returns to normal, and when return to sport tests (hop tests etc) are passed. Typically, it can take up to 12 months of excellent rehab to return to high-impact sports without increasing the risk of suffering a re-injury1.
Could returning to high-impact sports after ACL reconstruction be bad for your knee?
Unfortunately, people who have an ACL injury are at a high risk of developing early-onset knee osteoarthritis. In fact, about 50% of people with an ACL tear will develop osteoarthritis within 5-10 years, irrespective of surgical reconstruction or not2.
Currently, our understanding of the causes of this ‘early-onset osteoarthritis’ is not clear, but some preliminary data suggests that returning to high-impact sport may contribute3. That is why, in this month’s Special Issue on Osteoarthritis Prevention in the international journal Osteoarthritis and Cartilage, we have published a study to answer this exact question4.
In our longitudinal study (https://doi.org/10.1016/j.joca.2021.04.003) where we followed 81 people from 1 to 5 years after ACL reconstruction (infographic below), we found that the 37% of people who returned to high-impact (pivoting) sports like football and basketball at 1 year post-ACL reconstruction did not have an increased risk of developing osteoarthritis (using MRI scans and X-rays) or worse pain. We also observed that the 62% of people who returned to high-impact sports at any time within the first 5 years after ACL reconstruction, did not have an increased risk of osteoarthritis or worse pain.
Based on these findings, people with an ACL reconstruction can return to high-impact sports knowing that they are not putting their knee at higher risk of knee osteoarthritis.
Regaining muscle strength around the knee and function (eg. hopping ability) is critical for a safe return to sport (to reduce re-injuries) and long-term knee health1, 5.
- Grindem et al., Br J Sports Med. 2016;50:804-8.
- Culvenor et al., Br J Sports Med. 2013;47:66-70.
- Culvenor et al., Br J Sports Med. 2016;50:260-1.
- Haberfield et al., Osteoarthritis Cartilage. 2021;29:1673-81.
- Oiestad et al., Osteoarthritis Cartilage. 2015;23:171-7.
Post by Melissa Haberfield under the supervision of Dr Adam Culvenor