ACL Injury - The Holistic Approach

The mechanism of ACL injury appears to be multiplane knee loadings. The ACL may get overloaded if there is exerted vigorous quadriceps' force combined with frontal-plane or transverse-plane with insufficient hamstring muscle contraction, especially when the knee is near-extension or hyperextension.

Causes: Most of the ACL injuries are reported to occur with noncontact mechanisms, such as landing from a jump and sudden deceleration of the body while running along with a sudden change in direction.

Chief complaint: In many cases, patients reported that the knee went into valgus due to internal or external rotation while the knee was hyper-extended or in a shallow knee flexion at an angle of 20◦.

Surgical Interventions for An ACL Injury

At Amandeep Hospitals, patients often present with complaints of knee pain and swelling, accompanied by difficulty in walking. After a thorough evaluation and necessary investigations, Arthroscopic ACL repair is performed using an ipsilateral Hamstring and Gracilis graft.

Following the surgery, Phase 1 rehabilitation is initiated, which includes closed-chain knee exercises and hamstring isometrics. Patients are advised to engage in full weight-bearing walking with the assistance of advanced technological interventions for a duration of four weeks to ensure optimal recovery and gradual progress. Check Below to Observe How We Mark A Difference:

Post Surgery Physical Therapy for an ACL Injury

1. Range of Motion & Flexibility

   Restoring and maintaining full range of motion (ROM) in the knee is crucial after ACL reconstruction (ACLR). Early-stage quadriceps re-training has been shown to effectively improve ROM. Achieving full knee extension at the earliest opportunity is not harmful to the graft or joint stability and can help prevent patellofemoral pain and compensatory gait abnormalities. Additionally, a stretching program is incorporated to maintain flexibility in the lower extremities, supporting overall recovery and functional movement.
   

2. Gait Retraining

   Altered gait kinematics due to quadriceps dysfunction is common in the early stages following ACL reconstruction (ACLR). These adaptations often include reduced cadence, shortened stride length, altered swing and stance phase knee ROM, and decreased knee extensor torque, compensated by hip and/or ankle extensor adaptations.
   

   Early weight-bearing is suggested post-ACLR to restore gait kinematics efficiently, facilitate vastus medialis activation, and reduce the risk of anterior knee pain.
   

   In the middle stages of rehabilitation, treadmill training can further aids in normalizing lower extremity ROM across all joints. Incline or backwards walking on a treadmill has been shown to increase ROM, enhance functional quadriceps strength, and minimize patellofemoral stress. Additionally, backwards treadmill walking is particularly beneficial for return-to-sport preparation, as it retrains backwards locomotion critical for specific sports movements.

   

   
   

3. Muscular Strength & Endurance Training

   Muscle analysis of the quadriceps post-ACL injury reveals:

   1. Similar levels of atrophy in both type I (oxidative/endurance) and type II (glycolytic/fast-twitch) muscle fibers.

   2. Physiological metabolic shifts in muscle fibers from glycolytic to oxidative compositions.

   This underscores the need for variable training parameters in ACL rehabilitation. Rehabilitation should include:

   • Endurance training: Low load, high repetitions to address oxidative deficits.

   • Strength-oriented training: High load, low repetitions to target strength deficits.

   The type of graft used in ACL reconstruction (patellar tendon vs. semitendinosus/gracilis) influences strength deficits:

   • Patellar tendon graft: Low-velocity concentric extensor deficits specific to 60–95°.

   • Hamstring graft: High-velocity eccentric flexor deficits specific to 60–95°.

   Strengthening exercises should therefore be tailored to address these deficits, focusing on velocity, ROM, and contraction specificity.

   

4. Neuromuscular & Proprioceptive Retraining

   Proprioception training should ideally begin immediately after injury and before surgery, as ACL injuries disrupt proprioceptive input and neuromuscular control. Post-operatively, proprioceptive training must be initiated early to enhance neuromuscular integration and should continue for more than a year, as deficits can persist beyond this time frame.

   Key benefits of proprioceptive exercises:

   • Activation of compensatory muscle activation patterns, improving joint stability.

   • Enhanced strength gains in quadriceps and hamstring muscles post-ACLR.

   In the later stages of rehabilitation, anticipated and unanticipated perturbation training helps improve dynamic knee stability. A dynamically stable joint depends on a well-functioning proprioceptive and neuromuscular system. Functional outcomes have been shown to correlate highly with balance in reconstructed ACLs.

   

5. Return to Sport

Gradual return to sport is recommended between the 6–9 month mark, provided the individual’s knee:

• Is free from pain or effusion during and after functional sport-specific training drills.

• Achieves a LEFS score of 76 or greater.

• Demonstrates appropriate strength and endurance specific to their sport.

This timeline accounts for the recovery of knee cartilage and subchondral bone, which may be damaged during initial ACL trauma, to minimize the risk of future joint arthrosis.

Caution must be exercised when using the uninjured limb as a baseline for rehabilitation endpoints. Studies show significant detraining effects in both the injured and uninjured quadriceps and hamstring muscles, emphasizing the need for individualized assessments.