Recovery Stages After Anterior Crucuiate Ligament Reconstruction

Postoperative rehabilitation after anterior cruciate ligament (ACL) surgery is essential for restoring strength and function and promoting return to sport while minimizing risk of reinjury. The recovery process typically spans 9 to 12 months, delineated in a phased, criterion-based approach to monitor milestones, restore function and confidence, and promote return to sport. The early phase (weeks 0-6) focuses on reducing pain and swelling while restoring knee range of motion (ROM) and quadriceps strength (≥60% limb symmetry index [LSI]) with the use of modalities such as neuromuscular electrical stimulation. Open kinetic chain exercises can be initiated after surgeon clearance and appropriate progression to safely load the quadriceps without placing excessive strain on the reconstructed ACL. The intermediate phase (weeks 7-9) commences when the early-phase goals of knee ROM of 0° to 115°, effusion of 1+ or less, and a normalized gait pattern are achieved. This phase focuses on initiating balance activities, neuromuscular re-education, and aerobic training. Key goals of this phase include full, symmetrical ROM and quadriceps strength with an LSI of 70% or greater, which is achievable when adhering to a structured, progressive overload strength training program. The late phase (weeks 10-16) introduces running when quadricep strength reaches an LSI of 80% or greater and emphasizes training of proper landing mechanics. Strength training is progressively advanced and transitioned to a more intensive, gym-based program with a target LSI of 75% to 80% or greater. The transitional phase (months 4-6) initiates jumping, sprinting, decelerating, and agility drills. Goals include an LSI for quadriceps strength and hop testing of 85% or greater. The return-to-sport phase (months 6-12) emphasizes sport-specific drills and conditioning in preparation for return to competition. Clearance for full return to sport and competition should be provided when there is no pain or effusion, the patient attains an LSI for quadriceps strength and hop testing of 90% or greater, and fear/confidence levels are evaluated. This phased rehabilitation approach with criterion-based objective milestones allows patients to safely return to sport at preinjury levels while minimizing risk of reinjury.