Imaging of the Postoperative Meniscus

Area of Science:

• Orthopedic Imaging
• Musculoskeletal Radiology
• Meniscal Injury Imaging

Background:

• Postoperative changes after meniscectomy or meniscal repair can mimic meniscus re-tear on MR imaging.
• Accurate diagnosis requires understanding meniscal tear treatments and expected postoperative appearances.

Purpose of the Study:

• To define MR imaging criteria for differentiating expected postoperative changes from actual meniscus re-tear.
• To aid in protocol selection and accurate diagnosis in the postoperative setting.

Main Methods:

• Review of MR imaging findings in the context of meniscal surgery.
• Correlation of imaging findings with clinical outcomes and surgical procedures.
• Establishment of specific criteria for identifying meniscal re-tear.

Main Results:

• Overlap exists between expected postoperative changes (e.g., increased T1 signal) and re-tear findings.
• Key MR imaging criteria for meniscal re-tear include high T2 signal reaching the articular surface, abnormal morphology, or displaced fragments.
• MR arthrography may show variable signal intensity in re-tears compared to intra-articular contrast.

Conclusions:

• Clear MR imaging criteria are essential for diagnosing meniscus re-tear postoperatively.
• Knowledge of surgical procedures and expected imaging findings improves diagnostic accuracy.
• Differentiating re-tear from healing is critical for appropriate patient management.