Multiligament-injured knee: what the general orthopedic surgeon should know

Multiligament knee injuries (MLKIs) are rare but severe injuries involving bicruciate or collateral ligament disruption, frequently associated with knee dislocation, fractures, and neurovascular compromise. Vascular injury occurs in a mean of approximately 18% of cases and may be present despite palpable pulses; an ankle-brachial index (ABI) < 0.9 demonstrates high sensitivity for arterial injury. Peroneal nerve injury occurs in approximately 10-40% of cases. Early recognition and structured evaluation are critical. Serial vascular examinations, selective CT angiography, and careful neurologic assessment are mandatory. General orthopedic surgeons often make the initial management decisions, and timely diagnosis, stabilization, and referral significantly influence limb salvage and long-term function. The Schenck KD classification remains standard, with recent consensus refinements to the KD V category and proposed modifiers such as '-EM' for extensor mechanism disruption. Associated meniscal, chondral, and rare entities, such as uniplanar coronal tibiofemoral subluxation, require high clinical suspicion. Knee-spanning external fixation is indicated in vascular injury, open or fracture-dislocations, soft-tissue compromise, or persistent instability, with reconstruction commonly performed later at 3-6 weeks. Current evidence shows no clear superiority of early versus delayed reconstruction in functional outcomes, although early surgery increases stiffness risk. Anatomic reconstruction is generally favored over repair for high-grade PLC and MCL injuries due to lower failure and complication rates. At 2 years, patients retain approximately 80-85% of knee function; however, a gradual functional decline over time is observed. Arthrofibrosis (≈10%) remains the most common complication.