Lateral meniscus “PASTA injury”: Partial-thickness radial tear of the lateral meniscus: A case report

INTRODUCTION: We report a relatively rare case of partial-thickness radial tear in the inferior surface of lateral meniscus, while the superior surface is intact. This situation was similar to PASTA rotator cuff tear. Meanwhile, there is a full-thickness radial tear in the edge. CASE PRESENTATION: A 17-year-old boy twisted the left knee while playing basketball. Magnetic resonance imaging (MRI) revealed radial tear of the lateral meniscus. During arthroscopy, it was found that there was a full-thickness radial tear of about 2 mm located in the edge. Partial meniscectomy was performed to treat radial meniscal tear located in the white area. After that, we found that the superior surface of the lateral meniscus was intact. However, in the inferior surface of the lateral meniscus, partial-thickness radial tear was found extending to red zone. We used FASTFIX (Smith & Nephew) for all-inside suture. As of three months after this surgery, the patient recovered smoothly. DISCUSSION: Suspect that the force acts on a special position of meniscus and the thickness of the meniscus is uneven. Thus, it leads to partial-thickness radial tear in the inferior-surface, while the superior surface is intact. CONCLUSION: Partial-thickness radial tears in the inferior surface of lateral meniscus are relatively rare. This situation was similar to PASTA rotator cuff tear. Because the superior surface of the meniscus is intact, it may results in misdiagnosis. It's easy to ignore the inferior surface injury.