Composite knee tissue defects involving bone, meniscus, and ligaments caused by high-energy trauma are rare and present significant reconstructive challenges. We report a case of a 50-year-old woman with bilateral asymmetric knee injuries from a traffic accident, including right medial femoral condyle loss with medial collateral ligament (MCL) deficiency, and left-sided bone–meniscus–MCL complex loss, accompanied by 20% total body surface area skin degloving. Treatment was performed in three stages: debridement, soft tissue coverage, and final reconstruction using data-driven mirror modeling to design patient-specific 3D-printed titanium implants. The right MCL was reconstructed using a LARS artificial ligament. At 12-month follow-up, stable bone–implant integration, flap viability, and functional recovery were observed, with knee flexion of 120° (left) and 80° (right), and Knee Society Scores of 65 and 70. This case highlights the feasibility of personalized 3D-printed implants in complex bilateral knee reconstruction.