Which of the following factors is associated with prognosis after ACL reconstruction?

• A. Age, activity level, graft type, concomitant meniscal injuries, rehab compliance, smoking
• B. Age and sex
• C. Only graft type
• D. Only rehabilitation duration

Answer: (A)

Prognosis after ACL reconstruction depends on multiple interacting factors that influence healing, graft incorporation, knee stability, and the ability to regain function. Age and activity level shape both the biology of healing and the demands the graft must withstand; younger, more active patients may push the graft harder and have different failure risks, while older patients may have slower healing but lower activity demands. Graft type matters because different graft sources (autograft vs allograft) have distinct healing timelines, strength properties, and donor-site effects that can influence early stability and long-term outcomes. Concomitant meniscal injuries affect knee mechanics, joint surface health, and the risk of later osteoarthritis, all of which impact prognosis. Rehabilitation compliance is crucial to restore range of motion, strength, and neuromuscular control and to enable a safe return to activity; poor adherence is a major predictor of poorer outcomes. Smoking impairs healing and graft maturation by reducing blood flow and tissue healing capacity, further affecting prognosis. Taken together, these factors provide a more accurate picture than any single element alone.