The ACL (Anterior Cruciate Ligament) provides stability to the knee. Tearing the ACL can cause giving way during sports or buckling while walking down the street. Nonsurgical treatment focuses on restorating knee joint mobility, increasing quadriceps strength and endurance, agility training, protective bracing and active modification. Success with this treatment is most common in sedentary individuals or those willing to modify their sporting activities. Some people achieve higher levels of function with nonoperative management of an ACL injury, and it is possible for someone to compensate for the absence of the ACL by stabilizing the knee with muscle activation. These individuals have been termed copers, indicating that they can cope with the knee laxity that exists after ACL injury.

Copers:

  1. ACL only (No meniscus, PLC, MCL, LCL injury)
  2. Full pain free ROM
  3. No Joint Effusion
  4. Quadriceps Strength >70% (Injured/Healthy)
  5. Able to perform single leg hopping on injured leg

Screening:

  1. Single Leg Hop Testing: Single, crossover, triple and timed hop tests (>80%) (https://youtu.be/VUauqk9qLQA)
  2. Episodes of “giving-way” since injury (<2  since injury)
  3. Knee Outcome Survey (>80%)
  4. Global rating of Knee function (>60%)

There is an established screening process to determine if a person is a candidate for non-surgical rehabilitation following an ACL tear. Eastlack, et al. developed the following screening process. To participate in the screening process, the patient must have an isolated tear of the ACL (ie, non repairable meniscal injury and and no other concomitant ligamentous damage), full pain-free knee ROM and no knee joint effusion. These patients injured leg’s strength must equal at least 70% of the uninjured knee. Once this milestone is achieved, the patient must be able to tolerate single-leg hopping on the involved leg without pain. The screen is typically administered within two months of the injury. Some patients can reach these milestones within two days after injury, while others take much longer to achieve these goals.

If impairments, such as effusion or quadriceps weakness, are present, the patient will participate in a rehabilitation program until the deficits are resolved prior to initiation of the screening process. The screening includes 4 tests: (1) single, crossover, triple and timed hop tests. (2) Report of the number of giving-way episodes from the time of the injury to the time of testing. (3) the KOS ADLs scale and sports activity scale; and (4) a global rating of knee function, in which the patient self rates his level of function on a scale from 0 to 100, with 100 being full preinjury knee function. In the authors’ clinic, a functional knee brace is worn by all patients during the hop tests. Rehabilitation candidates are defined as patients who meet all 4 of the following criteria: (1) no more than one episode of giving way since injury, (2) score on the hop test of > 80%, (3) KOS ADLs scale score of >80%, and (4) global rating score of >60%.

If a patient is a candidate for non-operative ACL rehab they will go through weeks or months of Physical Therapy treatment with a focus on perturbation- training. Perturbation training consists of applying “destabilizing forces to the patients’ involved limb while the patient stands on tilt boards or roller boards” as previously discussed coupled with typical agility and strengthening program of the lower extremity. At the completion of Physical Therapy, patients must resume full participation in high level sporting activities for a full year to be considered true “copers”. Level I sports are defined as those that encompass jumping, cutting and pivoting types of maneuvers for 50 hours or more per year (soccer, football, basketball). Level II sports are those that involve lateral motion (skiing). Patients who are not considered rehabilitation candidates due to an inability to meet the threshold on any one of the 4 criteria are considered “noncopers” and are referred back to their orthopedic surgeon. Currently, there is no evidence for effective rehab of this group long term. In the United States today, patients who play to continue high intensity participation in Level I and II sports most often opt for surgical stabilization usually on the advice of their physician.

Click here to see videos demonstrating Physical Therapy for copers:

Perturbation training videos:

Citation
Manal, Tara Jo, et al. The Knee: Physical Therapy Patient Management Utilizing Current Evidence. Orthopaedic Section, APTA, Inc., 2011.