Can rehab be faster for athletes to return to sports?

By Jonathan Cluett, MD 

 Medically reviewed by Yaw Boachie-Adjei, MD

For many athletes, an anterior cruciate ligament (ACL) tear means the end of the athletic season and sometimes even the following season.

ACL reconstruction surgery is a common approach to repairing a ruptured ACL. When combined with a structured rehabilitation program, a person can often return to sports at the same level of play they enjoyed before the injury. Even so, ACL rehabilitation can and does take months. 

There is one question that most athletes will ask when faced with ACL rehab: is there any way to speed up the process?

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This article describes what is involved in ACL rehabilitation and how long you can expect to undergo physical therapy before you can confidently return to sports and other physical activities.

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Goals of ACL Tear Rehab

A new ligament is created and held in place in your knee with screws or other fixation devices when you have ACL reconstruction. The ACL then has to heal in this position to withstand the repetitive stress of sports.

The problem with any ACL graft is that it will eventually fail if the graft is repeatedly stressed before it has healed in position. That means the new ACL graft can become loose or re-torn.1

ACL tear rehabilitation is considered essential to getting you back into competition form to avoid this.

The goals of ACL tear rehab are fourfold:2

• To decrease knee pain and discomfort

• To increase the knee joint's range of motion

• To ensure the rotational stability of the knee

• To help prevent future injuries and joint degeneration

Rehabilitation after an ACL reconstruction is a long but well-developed process. Many healthcare providers have their specific protocols, but the process is typically structured in phases to ensure you meet the appropriate goals before moving to the next step.

ACL Reconstruction vs. ACL Repair

ACL reconstruction surgery is not the same thing as an ACL repair in which the torn ligament is surgically reconnected. Compared to ACL reconstruction surgery, ACL repair surgery is more likely to result in persistent knee instability and re-injury.3

ACL Tear Rehab Phases

After ACL reconstruction surgery, the rehabilitation process is broadly outlined in five phases from immediate post-operative recovery right through to the return to sports.4

Phase 1: Week 0-2 (Immediate Post-Operative Recovery)

The goals of the first days following ACL reconstruction are to minimize swelling and prevent discomfort. This can be accomplished with:

• Frequent ice application

• Elevation of the affected knee

• The use of crutches

Range of motion exercises can begin almost immediately after surgery. The initial focus is to regain full knee extension (the ability to straighten the knee). Flexion (the ability to bend) is much easier to recover than extension.1

After the first week of recovery, your physical therapist (PT) will start you on gait training, gentle strengthening, and aerobic exercises. Some PTs like to use stationary cycles as soon as possible, improving strength, motion, and aerobic fitness.

Controversies in ACL Rehab

Some surgeons may recommend a knee brace after ACL surgery. This is controversial, and many orthopedists avoid using them due to the lack of evidence that they actually help.5 Equally controversial is the use of continuous passive motion (CPM) machines which require a person to remain in bed rather than engage in active therapy.6

Phase 2: Weeks 3-6

During Phase 2, work is continued with physical therapy. As the range of motion increases, the emphasis is shifted from knee extensions to strengthening the muscles around the knee. Balance and proprioceptive exercises (which help your body know where it is in a space) are key parts of Phase 2.

Once normal motion has been achieved, some sport-specific activities can be started. Before starting any sports-specific activities, the knee range of motion must be near normal, and the swelling in the knee should be entirely gone.

Phase 3: Weeks 7-12

Early sports activities can be started during Phase 3, such as light jogging, outdoor cycling, and pool workouts. Side-to-side, pivoting sports—such as basketball, soccer, and football—must be avoided.

Toward the end of this phase, some athletes can begin shuttle runs, lateral shuttles, and jumping rope.

Phase 4: Months 3-6

Continued progression with sports-specific activities is the focus of Phase 4. This rehabilitation phase is often the most difficult because people may have a knee that "feels" normal but is not yet ready for the stresses of strenuous sports.

The emphasis of Phase 4 is on sport simulating activities. This includes figure-of-eight drills and plyometrics (which require you to jump and land in safe, specific ways). Over time, sports drills can be incorporated into the plan. For example, a tennis player may start light-hitting, while a soccer player might engage in controlled dribbling.

Phase 5: Month 6+ (Return to Sports)

Phase 5 can take anywhere from six months to a year depending on the extent of the injury, the type of graft used, and other factors. During this phase, the focus is placed on sport-specific motions and activities under the supervision of a PT or sports medicine practitioner.

At the end of Phase 5, your orthopedic surgeon can assess whether you can safely return to sports.

Returning to Sports Too Soon

Deciding when to return to unrestricted sports activities depends on several factors, including:2

• Functional progression: The decision to return to sports is based on each individual's progression through their physical therapy program.

• Graft type: Some surgeons may delay return to sports if the graft used to reconstruct the ACL came from a donor. Because these grafts are sterilized and frozen, the process can delay healing in some people.

• Surgeon preference: Your orthopedic surgeon will guide your rehabilitation and make the ultimate decision as to whether you can return to sports.

Some people will try to rush things and ignore their surgeon's recommendation. The consequences of this can be catastrophic, leading to re-rupture and another possible round of surgery.

By way of example, former NFL wide receiver Jerry Rice famously made a comeback 3.5 months after undergoing ACL reconstruction in 1997. In his first game back, he fractured his kneecap from where the graft was taken from. The new injury ended his season before it barely began.7

How Soon Is Too Soon?

Although some athletes can return to sports well ahead of the proposed timelines, they are more the exception than the rule. Studies suggest that athletes who have undergone ACL reconstruction and return to sports before 9.5 months are more likely to re-injure the ACL than those who delay.8

Preventing Re-Injury

The time it takes to recover from ACL reconstruction surgery can vary from one person to the next. Numerous factors can influence recovery times, including:9

• The type and severity of ACL injury

• Body mass index (BMI)

• A person's anatomy

• The type of sport a person plays as well as the level of play

• The type and size of the graft

• The level of adherence to the rehabilitation plan

Of all the factors listed above, there is only one you can fully control: how strictly you follow the rehabilitation program. Commitment is key to an unrestricted return to sports.

Summary

Recovery from cruciate ligament (ACL) reconstruction surgery takes time and patience. The rehabilitation plan, overseen by an orthopedic surgeon and facilitated by a physical therapist, is typically structured in five phases, from immediate post-operative recovery to the return to sports. The process generally takes at least six months and likely longer.

Recovery from ACL reconstruction is influenced by several factors, including the severity of your injury, the type of graft you have, the sports you engage in, the level of play, and your commitment to the rehabilitation program. This last factor is arguably the most important and the one you can fully control.

Sources

Bliss JP. Anterior cruciate ligament injury, reconstruction, and the optimization of outcome. Indian J Orthop. 2017;51(5):606-613. doi:10.4103/ortho.IJOrtho_237_17

Bousquet BA, O'Brien L, Singleton S, Beggs M. Post-operative criterion based rehabilitation of AL repair: a clinical commentary. Int J Sports Phys Ther. 2018 Apr; 13(2): 293–305.

Chahla J, Nelson T, Dallo I, et al. Anterior cruciate ligament repair versus reconstruction: a kinematic analysis. Knee. 2020 Mar;27(2):334-40. doi:10.1016/j.knee.2019.10.020

Cavanaugh JT, Powers M. ACL rehabilitation progression: where are we now? Curr Rev Musculoskelet Med. 2017 Sep;10(3):289–96. doi:10.1007/s12178-017-9426-3

May HO, Stueken P, Munch EO, et al. Brace or no-brace after ACL graft? Four-year results of a prospective clinical trial. Knee Surg Sports Traumatol Arthrosc. 2014 May;22(5):1156-62. doi: 10.1007/s00167-013-2564-2

Trochimczuk R, Kuźmierowski T, Anchimiuk P. Study of CPM device used for rehabilitation and effective pain management following knee alloplasty. Int J Applied Mechanics Engineer. 2017;22(1):241-51. doi:10.1515/ijame-2017-0014

New York Times. Rice's 2d knee injury ends a lost season. December 17, 1997.

Gupta R, Singhai A, Malhotra A, Soni A, Masih GD, Raghav M. Predictors for anterior cruciate ligament (ACL) re-injury after successful primary ACL reconstruction (ACLR). Malays Orthop J. 2020 Nov;14(3):50–6. doi:10.5704/MOJ.2011.009

Middlebrook A, Middlebrook N, Bekker S, Rushton A. Physical prognostic factors predicting outcome following anterior cruciate ligament reconstruction: A systematic review and narrative synthesis. Phys Ther Sport. 2022 Jan;53:115-42. doi:10.1016/j.ptsp.2021.11.007

By Jonathan Cluett, MD
Jonathan Cluett, MD, is board-certified in orthopedic surgery. He served as assistant team physician to Chivas USA (Major League Soccer) and the United States men's and women's national soccer teams.