What is your diagnosis?

Bucket Handle Meniscus Tear. This case is an example of an acute meniscus injury. Plain films of the knee are often normal or only notable for joint effusion [1]. Advanced imaging, such as MRI, is often not obtained in the ED which makes recognizing the injury pattern and exam findings crucial to ensure appropriate referral and follow up with a specialist.

• Pearl: A bucket handle tear occurs when one of the menisci suffers a full-thickness tear. The edges of the torn meniscus flip over like that of a bucket handle, thus the name. In some cases, the edges of the torn meniscus can flip and roll over and get stuck in the knee joint. A bucket handle tear most often affects the medial meniscus [2].

How does this injury present in the ED?

History will often include a description of a sudden twisting or turning rotation +/- an audible pop. Pain is often described on the affected side of the joint line and swelling may wax and wane. Patients will often endorse clicking or giving way or even locking of the joint, which is more suggestive of a bucket handle tear [2]. 

• Pearl: Physical exam special tests can increase specificity and sensitivity of the diagnosis:

• McMurrays Test: Passively flex and extend knee in medial and lateral rotation

• Apley Grind Test: Prone, affected knee flexed to 90°, medial and lateral rotation with compression

• Thessaly Test: Standing, knee bent 20-30°, rotate knee medial and laterally

What is your disposition and how soon to follow up?

Once more emergent causes of knee pain have been excluded in the ED, these patients may be safely discharged with a compressive or hinged knee brace for comfort and NSAIDs. Ambulation should be encouraged as soon as comfortable. However, differing from other meniscal tears, urgent referral to an orthopedist/sports medicine specialist within 1-2 days is recommended for advanced imaging (MRI) and operative planning to restore ROM as soon as possible [1]

Radiographic findings?

Images 3 and 4. MRI R Knee (Sagittal PD) Cases 

courtesy of Dr. Ahmed Abdrabou,  Radiopaedia.org, rID: 25091

• 'Double PCL sign' (Image 3) appears on sagittal MRI images of the knee when a bucket handle tear of a meniscus (most commonly the medial meniscus) flips into the intercondylar recess and comes to lie anteroinferior to the PCL mimicking a second smaller PCL [3].

• 'Double delta sign' and 'ghost meniscus sign' (Image 4) is resultant of complete peripheral vertical longitudinal tear of the posterior horn and body of the lateral meniscus has allowed the posterior horn to flip into the intercondylar notch and the body to flip directly posterior to a truncated anterior horn [3].