What is a bucket handle (meniscal tear) injury in the knee?

What is a Bucket Handle Meniscal Tear?

A bucket handle tear is a specific type of meniscal injury characterized by a vertical longitudinal tear where the inner fragment of the meniscus detaches and displaces, typically flipping into the intercondylar notch of the knee, resembling the handle of a bucket. 1, 2

Anatomical Description

• The tear pattern involves a vertical longitudinal or oblique tear through the meniscus where the inner fragment remains attached at both ends but becomes displaced from its normal position 3
• The displaced fragment most commonly flips into the intercondylar notch region, though it can also flip anteriorly 4, 3
• These tears represent approximately 10% of all meniscal tears 2
• Both medial and lateral menisci can be affected, though medial meniscus involvement is slightly more common (56% medial vs 44% lateral in pediatric populations) 1

Clinical Presentation

• Patients typically present with acute knee pain, joint locking, and a sensation of instability following a twisting injury, most commonly during sports activities 5, 1
• The mechanical locking occurs because the displaced meniscal fragment physically blocks normal knee motion 6
• These injuries occur predominantly in younger, active patients with a mean age around 15-24 years in most case series 4, 1
• Males are affected more frequently than females (approximately 63% male) 1

MRI Diagnostic Features

MRI is the gold standard imaging modality for diagnosing bucket handle tears, with 96% sensitivity and 97% specificity at 3T 6

Classic MRI Signs Include:

• "Fragment within the intercondylar notch sign" - the displaced meniscal fragment is visible in the notch 3
• "Double PCL sign" - the displaced fragment appears parallel to the posterior cruciate ligament on sagittal images 4, 3
• "Absence of the bow tie sign" - the normal meniscal body appearance is missing on consecutive sagittal images 3
• "Flipped meniscus sign" - the fragment is flipped anteriorly or into the notch 4, 3
• "Pelican sign" - a unique appearance on axial sequences when the fragment is flipped anteriorly, resembling a pelican bird 4
• "Double anterior horn sign" - two meniscal fragments visible where only one should appear 3

Associated Injuries

• Bucket handle tears frequently occur in conjunction with anterior cruciate ligament (ACL) injuries, with approximately 37% of cases having concurrent ACL tears requiring reconstruction 1, 2
• Other associated injuries include lateral meniscus tears, bone marrow contusions, and posterolateral corner injuries 7, 5
• MRI performed within 6 weeks of acute trauma provides better visualization of associated ligamentous injuries compared to delayed imaging 6

Clinical Significance

• These tears typically require surgical intervention, as the displaced fragment causes mechanical symptoms and the tear pattern involves significant meniscal disruption 1, 2
• MRI can change management from surgical to conservative in up to 48% of patients presenting with a locked knee, making accurate diagnosis critical 7, 6
• The presence of a bucket handle tear warrants urgent orthopedic evaluation, as these injuries can lead to additional cartilage and meniscal damage if left untreated 8