import { ContentSection, EvidenceCard, ExamCheatSheet, ExamPearl, ExamWarning, InfoCard, InfoCardGrid, MedicalImage, MnemonicCard, OnePagerSummary, Tab, Tabs, VivaScenario, VivaScenarioSection } from '@/components/mdx' **Posterior drawer test**: 90° flexion, push tibia posteriorly. **Sag sign**: Tibia drops in 90° flexion. **Quadriceps active test**: Tibia moves forward with quad contraction. **I**: 1-5mm, tibia anterior to medial femoral condyle. **II**: 6-10mm, tibia flush. **III**: greater than 10mm, tibia posterior. Grade III = surgery. **Grade III instability** (greater than 10mm). **Multiligament injury** (especially with posterolateral corner). **Symptomatic Grade II** failing conservative. **Athletes**. **Transtibial technique**: Sharp angle as graft exits tibial tunnel ("killer turn"). Can abrade graft. **Tibial inlay** avoids this but requires posterior approach. {/* REMOVED: 1-search-strategy-and-results-for-systematic-review-.png */} The **posterior cruciate ligament (PCL)** is the primary restraint to posterior tibial translation. It is the thickest ligament in the knee. ### Mechanism **Dashboard injury**: Classic mechanism. Flexed knee, posterior force on proximal tibia (e.g., knee hitting dashboard in MVA). **Hyperflexion**: Non-contact fall onto flexed knee. **Hyperextension**: Can injure both cruciates. ### Anatomy **Two bundles**: Anterolateral (larger, tighter in flexion) and posteromedial (tighter in extension). **Tibial insertion**: Posterior tibial fovea, well below articular surface. ### Examination **Posterior Drawer Test**: 90° flexion, stabilize foot, push tibia posteriorly. Positive = increased laxity. **Sag Sign (Godfrey's Test)**: 90° hip and knee flexion, observe lateral profile. Tibia sags posteriorly compared to other side. **Quadriceps Active Test**: 90° flexion, foot fixed, contract quads. PCL-deficient tibia moves anteriorly (from posteriorly subluxed position). **Dial Test**: Assess posterolateral corner if associated injury suspected. ### Grading **Grade I**: 1-5mm translation, tibia still anterior to medial femoral condyle. **Grade II**: 6-10mm, tibia flush with condyle. **Grade III**: greater than 10mm, tibia posterior to condyle. **Indications**: Isolated Grade I-II. Low-demand patients. No associated injuries. **Treatment**: Quadriceps strengthening is key (reduces posterior tibial sag). Brace. Activity modification. ROM exercises. **Outcomes**: Many isolated PCL injuries function well non-operatively. Focus on quadriceps strength. **Indications**: Grade III instability. Multiligament injury. Symptomatic Grade II failing conservative. Athletes. **Graft**: Achilles allograft (most common), quadriceps, hamstring, BTB. **Techniques**: **Transtibial**: Most common. Tibial tunnel from anteromedial tibia. "Killer turn" where graft exits can abrade graft. **Tibial Inlay**: Graft fixed to flat posterior tibial surface. Avoids killer turn. Requires posterior approach. **Single vs Double Bundle**: Double bundle may better restore rotational control. Single bundle biomechanically sound. **Femoral Tunnel**: Placed in native PCL footprint.

PCL Reconstruction

PCL Reconstruction