TABLE 42.1 DIFFERENTIAL DIAGNOSIS OF THE INJURED KNEE Acute injuries Fractures Distal femoral epiphysis a Proximal tibial epiphysis a Tibial tubercle avulsion Patella Tibial spine avulsion Osteochondral fractures Soft tissue injuries Collateral ligament sprain b or tear Anterior cruciate ligament sprain or tear Posterior cruciate ligament sprain or tear Meniscal tears Quadriceps tendon rupture Patellar tendon rupture Hamstring strain b Posttraumatic infections a Dislocations and subluxations Patellar b Knee joint a Subacute injuries Osgood–Schlatter disease b Patellofemoral dysfunction b Patellar tendonitis (jumper knee) Prepatellar bursitis Osteochondritis dissecans (OCD) Baker cyst Iliotibial (IT) band syndrome Other Pathologic fractures a Referred pain from hip disease Slipped capital femoral epiphysis Avascular necrosis of the femoral head a Life- or limb-threatening causes of the injured knee