The optimal window for reconstruction of the anterior cruciate ligament (ACL) with respect to quadriceps atrophies lies within 21 to 100 days.

In patients who underwent ACL reconstruction within three weeks or after more than 100 days, a significantly higher incidence of quadriceps atrophy was observed, possibly attributable to the initial inflammatory phase or the delayed reconstruction affecting quadriceps function. However, this impairment may not be observable in elite athletes who undergo reconstruction within hours of the injury.