Return to Play After ACL Reconstruction

The goal of return to sport following ACL reconstruction is safe return to play with minimal risk of reinjury.  Returning too soon can risk rupturing the graft which can be a devastating complication.  Return to sport timing considers a multitude of factors, including other injuries to the knee (meniscus etc.), physical examination findings, functional testing such as single-leg jumping mechanics, psychological readiness, demands on the knee for the sport of interest, and biological tissue healing(1).  Recent evidence has suggested the benefit of individualizing the decision to return and erring on the side of waiting longer in younger patients playing higher-risk sports.  In fact, some studies suggest a reinjury incidence reduction of 51% for each month that return to sport is delayed at months 5 to 9 after surgery(2).  These studies support the concept that in high-risk groups, there is a minimum amount of time for muscle control, balance and position sense (proprioception), and graft maturation to improve following safe return to sport around 9 months after surgery.

There are also compelling reasons to get athletes back to sport in an accelerated fashion.  Keeping a competitive athlete off the field or court also has downsides, including impairing mental health, delaying opportunities for achievement including college scholarships, and limiting access to a social peer group.  Because of these factors, there has been interest in getting athletes back as soon as 6 months, if the knee is ready based on objective criteria.  Some of the criteria used for an accelerated return include stability, strength, single-leg hop tests, and quality of movement.

Knee surgeon Dr. Obermeyer’s preference is to apply an accelerated protocol when possible. Dr. Obermeyer uses shared decision making to help guide the injured athlete back to function with an eye toward limiting risk of reinjury.  The patient has a role in the decision to return and should not only be physically but psychologically ready, being confident the knee feels good and can perform at competition level.

Immediately after surgery, patients should wear the brace completely extended at all times, including for sleep, to protect the knee.  For the first couple weeks, the goal is letting the swelling to subside, activating the quadriceps, and getting the knee to full extension (straight).  Straight leg raises, ankle pumps, and quad sets are used.

The brace is typically discontinued around 4 weeks when quadriceps strength is normal.  Work is done on restoring a full range of motion from zero to 125 degrees.  Strengthening is advanced to mini squats and leg press exercises.  Once the motion is back to normal, progressive strengthening begins, with progressive squatting and leg presses at 6-12 weeks.  Agility exercises and retrograde treadmill walking are implemented during this timeframe.

A forward running program on a treadmill is begun around 3 months after surgery, when there is no pain and good motion on a 15-cm eccentric step-down test.  This test indicates the muscles are strong and there is limited pain coming from the kneecap area.  After running is initiated, there are sport-specific movements started including lateral motion for agility.  Throughout, quadriceps and hamstrings strengthening is performed and around 5 months, plyometrics are begun which involves jumping and landing mechanics and activating the core.