This patient has most likely sustained an ACL tear. This is supported by the history and positive Pivot Shift Test on physical exam. The most common bone bruise pattern resulting from an acute tear of the ACL is the central third of the lateral femoral condyle and posterior third of the lateral tibial plateau (shown in Figure A).
The article by Graf et al found that 43% of ACL tears had an associated bone bruise on MRI if the image was taken within 6 weeks of injury. There was no correlation between the presence of a bone bruise and articular alterations or meniscal tears observed at surgery.
In a prospective study (MOON Database) Dunn et al found that 418 of 525 (80%) patients with an ACL tear had bone bruising. They found that bone bruising is not associated with symptoms/pain at the time of index anterior cruciate ligament reconstruction.
Yoon et al found that 84% of patients with ACL tears had bone bruises. The lateral femoral condyle was the most common location (68%). They found injuries of the menisci and the MCL tended to increase with the progression of bone contusion.
Answer 2: Figures B shows an anterior tibia contusion.
Answer 3: Figure C shows a bone contusion pattern consistent with a patellar dislocation.
Answer 4: Figure D shows an anterior femoral condyle contusion.
Answer 5: Figure E (meniscotibial ligament avulsion) show bone contustion patterns are consistent with a hyperextension injury (an example would be a PCL tear).
Illustration A is a link to a video demonstrating the Pivot Shift Test.
Graf BK, Cook DA, De Smet AA, Keene JS. "Bone bruises" on magnetic resonance imaging evaluation of anterior cruciate ligament injuries. Am J Sports Med. 1993 Mar-Apr;21(2):220-3.
PMID:8465916 (Link to Abstract)
Dunn WR, Spindler KP, Amendola A, Andrish JT, Kaeding CC, Marx RG, McCarty EC,Parker RD, Harrell FE Jr, An AQ, Wright RW, Brophy RH, Matava MJ, Flanigan DC, Huston LJ, Jones MH, Wolcott ML, Vidal AF, Wolf BR; MOON ACL Investigation. Which preoperative factors, including bone bruise, are associated with knee pain/symptoms at index anterior cruciate ligament reconstruction (ACLR)? A Multicenter Orthopaedic Outcomes Network (MOON) ACLR Cohort Study. Am J Sports Med. 2010 Sep;38(9):1778-87. Epub 201
PMID:20595556 (Link to Abstract)
Yoon KH, Yoo JH, Kim KI. Bone contusion and associated meniscal and medial collateral ligament injury in patients with anterior cruciate ligament rupture. J Bone Joint Surg Am. 2011 Aug 17;93(16):1510-8.
PMID:22204006 (Link to Abstract)