In previous posts, we have presented our theory of how the anterior cruciate ligament (ACL) gets torn, the pre-operative process of a reconstruction, and the surgical technique. Last month we started to discuss the post-operative rehab process with use of the ipsilateral (same side) patellar tendon graft. But before completing the rehab discussion, it is important to understand how we have evolved from using just the ipsilateral patellar tendon graft to now using primarily the contralateral (opposite side) patellar tendon graft.
Revision surgery for ACL reconstruction is much more demanding as it requires removal of any old hardware and making sure the tunnels are in the proper position, especially if the original reconstruction was done by another surgeon. We have previously discussed the benefits of doing a mini arthrotomy technique and we continue to use this with primary (initial) ACL reconstructions as well as revisions. However, in the mid-1990s, when Dr. Shelbourne was the team physician for Purdue, he had an athlete who re-tore his ACL and at that point, it was too soon to re-harvest (re-use the same patellar tendon) because of the timing from the patient’s primary ACL reconstruction. So, Dr. Shelbourne was forced to use the patellar tendon from the contralateral knee. During the rehabilitation process after surgery, the athlete commented to Dr. Shelbourne on how much easier and quicker the rehab was the second time.
There was a second athlete, in a different sport, who tore his ACL during his senior year and wanted to be able to play his senior year. The athlete asked Dr. Shelbourne to do the same thing he had done with the previous athlete given how quickly he was able to return to his sport. At this point in time, the use of a contralateral patellar tendon graft had never been used for a primary ACL reconstruction. After much thought and conversation with himself and the patient, Dr. Shelbourne did the primary ACL reconstruction with the use of the contralateral patellar tendon graft. The outcome was just as good as the previous athlete and from that point forward, the use of the contralateral patellar tendon graft has been the primary source of our ACL reconstructions. However, our physicians will use the ipsilateral patellar tendon graft with patients who choose this for whatever reason, or if there is an underlying problem with the contralateral knee that makes taking the graft from the ipsilateral knee a better option.
We discussed previously the first week of rehab having patients stay on bedrest, the ACL knee resting in a CPM machine with cold/compression device and starting the patient on a series of exercises for range of motion and quad control. These exercises are also performed on the contralateral leg and the only thing that is different between the two legs is the CPM, which is only for the ACL knee. The contralateral leg, graft donor leg, is kept elevated on pillows with cold pack over the tendon site. The patient starts using a shuttle press machine two days post-op as long as the patient can maintain full flexion. The donor leg never gets swelling in the joint as the patellar tendon is superficial and the surgeon never has to enter the joint. So, the only goal of the donor graft knee is to regenerate the patellar tendon donor site and then return strength in the quad. This graft leg typically does not lose range of motion. The patellar tendon will regenerate and actually hypertrophy (get up thicker) if doing appropriate low resistance and high repetition exercises. This progression of low weight/high reps on the donor graft knee continues for the first 6-8 weeks, or until the tendon is regenerated then the patient can start working on building quad strength.
The benefit of taking the patellar tendon graft from the contralateral knee is that you are splitting the rehab between the two knees. The ACL knee only has to get the swelling resolved and full range of motion, symmetrical to the opposite knee with rehab. While the graft knee only has to work on getting full quad strength back. We do not restrict weight-bearing status post-op and encourage normal gait by one week. Therefore, there is not a major loss of proprioception (awareness of the position and movement of a body part) to have to work on during the rehab phase. When the graft is taken from the same knee, it is imperative to get the swelling under control and get full, or close to full, range of motion back to normal before pushing strength. Starting the strengthening process before range of motion is under control creates the risk of increased swelling, which will limit the patient’s ability to get full flexion (bending). This creates a “balancing act” of progression of strength without loss of motion or increase in swelling. This is why taking the graft from the contralateral knee allows for a quicker rehab and recovery. Once the two knees are symmetrical in range of motion and strength, the patient can start doing more activities, including sports-specific drills.
Our patients are typically seen at the following post-op time frames: 1 week, 2 weeks, 4 weeks, 8 weeks, 3-4 months, 6 months, 9 months and then one year. At the 2 months post-op visit, we repeat all the pre-operative tests to determine where the patient is with stability, range of motion and strength comparing side-to-side with isokinetic testing. The goal for return to sport is to have no swelling, full range of motion and symmetrical quad strength. Many patients are at or close to this goal between 2 and 4 months post-op. They may not be ready for full participation, but they are ready to start doing sport-specific activities and participating in 50% or more of their sport.
The “Accelerated Rehab” protocol that was published in the 90’s was not given this title because it was expected to get patients back to sport quicker. It was given this title because after following this group of patients over a period of time, it was found that taking the graft from the opposite knee allowed for an outcome that led to quicker and more predictable return to play for most patients. You can reference this article and the rehab in more detail. Next month, we will discuss the return to sport rates post-operatively for our ACL reconstruction patients.
Shelbourne KD, Nitz P: Accelerated Rehabilitation After Anterior Cruciate Ligament Reconstruction. Am J Sports Med 18, 292-299, 1990.
Shelbourne KD, Gray T. Principles of Anterior Cruciate Ligament Rehabilitation. IN Prodromos CC (ed), Anterior Cruciate Ligament: Reconstruction and Basic Science, 2nd edition, Elsevier, Philadelphia, PA