Evidence for the effects of prehabilitation before ACL-reconstruction on return to sport-related and self-reported knee function: A systematic review.

After an anterior cruciate ligament (ACL) tear, most attention goes to what happens after surgery, but what if the weeks before reconstruction also matter? This review asked whether prehabilitation, meaning structured exercise done before ACL surgery, changes knee strength, self-reported function, and return to sport compared with usual preoperative care. It pulled together a small body of evidence: two randomized trials, two other controlled trials, and two cohort studies, rated as only moderate quality overall. Across these studies, prehabilitation groups tended to show greater gains in quadriceps strength before surgery, less decline in hop-test performance and strength symmetry between legs after surgery in some studies, and higher self-reported knee function both before surgery and at two years afterward, with return to sport also appearing faster and more frequent in one study.

The pattern is encouraging but built on very few studies, several outcomes reported by only one study each, and only moderate methodological quality, so the findings point toward a promising direction rather than settled proof.

If you're facing ACL reconstruction, you might wonder whether doing exercise before surgery, not just after, could help your recovery. This review looked at studies testing exactly that, comparing patients who did a structured pre-surgery exercise program with those who received usual care.

Overall, the studies found that people who did prehabilitation tended to build more thigh muscle strength before surgery, reported feeling their knee functioned better both before and up to two years after surgery, and in some cases got back to sport sooner and more often. That's a hopeful pattern, but it comes from a small number of studies, several outcomes were based on just one study each, and the overall quality of the research was rated only moderate. So while prehabilitation looks like it could be helpful before ACL surgery, this shouldn't be read as a firm guarantee since larger, higher quality studies are still needed to confirm these results.

This is a summary of research, not medical advice. Talk to your own healthcare provider about anything affecting your care.

This systematic review identified only six eligible studies (two randomized controlled trials, two controlled trials, two cohort studies) examining prehabilitation before ACL reconstruction, with methodological quality rated moderate on the PEDro scale (mean 6.5, range 4 to 9). Findings were consistent in direction but sparse in replication: two studies reported greater preoperative gains in maximal quadriceps torque, one via limb symmetry index and one bilaterally, in prehabilitation groups versus controls.

At 12 weeks postoperatively, one of two studies found a clinically meaningful smaller decline in single-leg-hop-for-distance limb symmetry index, with a similar single-study finding for quadriceps strength symmetry. Self-reported knee function favored prehabilitation groups at a clinically meaningful level both preoperatively (three studies) and at two years postoperatively (two studies), and return to sport was faster in one study and more frequent at two years in another. Given that most outcomes rest on one or two studies each, heterogeneous designs, and moderate risk of bias, these results should be interpreted as suggestive rather than conclusive.

The authors explicitly call for more high-quality confirmatory randomized controlled trials before firmer conclusions can be drawn.