Treatment of Lateral Tibial Plateau Impaction Fracture
For lateral tibial plateau impaction fractures, CT imaging should be obtained after initial radiographic diagnosis to guide treatment planning, followed by surgical open reduction and internal fixation (ORIF) for displaced fractures with articular involvement, while considering bone grafting for significant depression and evaluating for associated meniscal and ligamentous injuries that commonly occur with these fractures. 1
Initial Diagnostic Workup
- Obtain CT imaging after radiographic diagnosis to fully characterize fracture severity, classify the injury pattern, and predict associated soft tissue injuries 1
- CT demonstrates 100% sensitivity versus 83% for radiographs in detecting tibial plateau fractures and is superior for characterizing fracture severity 1
- Lateral tibial plateau depression >11 mm on CT predicts higher risk of lateral meniscus tears and ACL avulsion fractures, which should prompt consideration for MRI 1
- MRI is the next best imaging modality when suspecting additional radiographically occult fractures or internal derangements, given its superior evaluation of meniscal and ligamentous injuries 1
Surgical Treatment Approach
Open Reduction and Internal Fixation
- Perform ORIF with plate fixation for displaced lateral plateau fractures to restore articular congruity and allow early mobilization 2
- The goal is anatomic reduction of the articular surface with stable internal fixation to prevent post-traumatic osteoarthritis 2
- Immediate weight-bearing as tolerated can be initiated postoperatively when adequate fixation is achieved 3
Bone Grafting Considerations
- Consider impaction bone grafting as an adjunct for osteoporotic or significantly depressed fractures to provide structural support and prevent loss of reduction 3
- Allograft from 1-4 femoral heads (25-100 cm³) can be used for impaction grafting 3
- This technique allows immediate weight-bearing mobilization with full weight-bearing typically achieved by 6 weeks postoperatively 3
- Approximately 51% of graft area remodels into new host bone by 1 year 3
Management of Associated Injuries
Critical pitfall: Lateral tibial plateau impaction fractures have high rates of concomitant injuries that must be addressed:
- Lateral meniscus injuries occur in 36-80% of cases depending on fracture morphology 2, 4, 5
- Posterolateral impaction fractures with displaced osteochondral shear fragments are associated with lateral meniscus posterior root tears (33.3%) and MCL tears (61.1%) 4
- Perform meniscal repair rather than meniscectomy when possible, as meniscectomy results in 100% rate of post-traumatic osteoarthritis versus 20% with repair 2
- Evaluate for ACL injury, as 49.3% of primary ACL tears have associated posterolateral tibial plateau impaction fractures 4
Postoperative Management
- Initiate functional rehabilitation with motion restoration and strengthening exercises rather than prolonged immobilization 6
- Progress to full weight-bearing by 6 weeks with goal of normal gait by 3 months 3
- Monitor for complications including infection (12.2%), DVT (7.3%), and loss of reduction 2
Expected Outcomes and Complications
- Post-traumatic knee osteoarthritis develops in approximately 30% of patients overall, but is significantly higher (100%) after lateral meniscectomy 2
- Functional outcomes at 5-7 years follow-up: excellent 31.7%, good 51.2%, moderate 12.2%, poor 4.9% 2
- Local skin condition, soft tissue injuries, comminution degree, and depression severity significantly affect development of post-traumatic osteoarthritis 2