A twisting knee injury with knee deformity after sports is most consistent with which diagnosis?

A twisting knee injury with knee deformity after sports is most consistent with which diagnosis?

• A. Patella dislocation
• B. ACL tear
• C. Meniscal tear
• D. MCL sprain

Answer: (A)

Twisting knee injury with a clear deformity most strongly suggests a patellar dislocation. When the kneecap pops out of its normal groove, it typically shifts to the outside (lateral) of the knee, producing an obvious bend or deformity, pain around the front of the knee, and often an inability to straighten the leg. This hallmark finding—visible malalignment of the patella with acute knee pain after a twisting force—sets patellar dislocation apart from other common knee injuries. In contrast, an ACL tear usually presents with a popping sensation at the time of injury, immediate swelling from bleeding into the joint, and instability rather than a visible deformity of the knee. A meniscal tear might cause joint-line pain, swelling, and mechanical symptoms like locking or catching, but not a gross deformity of the knee. An MCL sprain typically shows medial knee tenderness and swelling with a valgus stress test, again without the dramatic patellar malalignment. If patellar dislocation is present, management in the acute setting focuses on pain relief, prompt reduction if indicated, and protecting the knee with immobilization and a plan for orthopedic follow-up to assess for associated injuries.

Twisting knee injury with a clear deformity most strongly suggests a patellar dislocation. When the kneecap pops out of its normal groove, it typically shifts to the outside (lateral) of the knee, producing an obvious bend or deformity, pain around the front of the knee, and often an inability to straighten the leg. This hallmark finding—visible malalignment of the patella with acute knee pain after a twisting force—sets patellar dislocation apart from other common knee injuries.

In contrast, an ACL tear usually presents with a popping sensation at the time of injury, immediate swelling from bleeding into the joint, and instability rather than a visible deformity of the knee. A meniscal tear might cause joint-line pain, swelling, and mechanical symptoms like locking or catching, but not a gross deformity of the knee. An MCL sprain typically shows medial knee tenderness and swelling with a valgus stress test, again without the dramatic patellar malalignment.

If patellar dislocation is present, management in the acute setting focuses on pain relief, prompt reduction if indicated, and protecting the knee with immobilization and a plan for orthopedic follow-up to assess for associated injuries.