Pain and tenderness over the patella with a joint effusion is most consistent with which diagnosis?

Pain and tenderness over the patella with a joint effusion is most consistent with which diagnosis?

• A. Patella fracture
• B. Tibial fracture
• C. ACL tear
• D. Meniscal tear

Answer: (A)

Pain and tenderness directly over the patella with a knee joint effusion points to injury of the patella itself, most typical for a patellar fracture. A direct blow to the knee or a fall onto the knee can crack the patella and bleed into the joint, producing localized patellar tenderness and an effusion from intra-articular bleeding. Because the extensor mechanism attaches to the patella, a fracture can disrupt knee extension and lead to swelling from blood accumulating in the suprapatellar pouch. In contrast, an ACL tear often presents with anterior knee pain and instability after a twisting injury, with laxity on tests rather than focal patellar tenderness. A meniscal tear may cause joint line tenderness and effusion but not predominantly over the patella. A tibial fracture would show tenderness along the tibia rather than the patella. Thus, the combination described best fits a patellar fracture. Imaging with knee X-rays (including a skyline view) will confirm the fracture. Immobilization, analgesia, and prompt orthopedic evaluation are typical steps in management, with surgery considered if displaced.

Pain and tenderness directly over the patella with a knee joint effusion points to injury of the patella itself, most typical for a patellar fracture. A direct blow to the knee or a fall onto the knee can crack the patella and bleed into the joint, producing localized patellar tenderness and an effusion from intra-articular bleeding. Because the extensor mechanism attaches to the patella, a fracture can disrupt knee extension and lead to swelling from blood accumulating in the suprapatellar pouch.

In contrast, an ACL tear often presents with anterior knee pain and instability after a twisting injury, with laxity on tests rather than focal patellar tenderness. A meniscal tear may cause joint line tenderness and effusion but not predominantly over the patella. A tibial fracture would show tenderness along the tibia rather than the patella. Thus, the combination described best fits a patellar fracture. Imaging with knee X-rays (including a skyline view) will confirm the fracture. Immobilization, analgesia, and prompt orthopedic evaluation are typical steps in management, with surgery considered if displaced.