Characteristic location and rapid progression of medial femoral condylar chondral lesions accompanying medial meniscus posterior root tear.

BACKGROUND

This study aimed to demonstrate the characteristics of the chondral lesion at the medial femoral condyle (MFC) in patients with medial meniscal posterior root tear (MMPRT), and to compare the progression rate of accompanying chondral disease in MMPRT with that in degenerative non-radial tear.

METHODS

Thirty-one patients who underwent arthroscopic surgery for MMPRT and 31 controls who underwent arthroscopic surgery for degenerative medial meniscus posterior horn horizontal tear (MMPHT) were included. Accompanying chondral lesions in the MFC were evaluated by magnetic resonance imaging (MRI) at initial diagnosis and from video taken at arthroscopic surgery using the International Cartilage Repair Society (ICRS) classification system. The difference in severity and extent of the chondral lesion between initial diagnosis and surgery was measured.

RESULTS

Twenty-five patients with MMPRT (80.6%) and 29 patients (93.5%) with MMPHT had ICRS grade ≥2 chondral injuries at MFC. In the MMPRT and MMPHT groups, the most severely injured areas of the MFC were the far medial compartment (52%) and central compartment (51%), respectively. Comparing MRI and arthroscopy, 12 patients (39%) in the MMPRT group showed progression of chondral disease after a mean of 3.5 months, whereas only three patients (10%) in the MMPHT group showed progression after a mean of 3.1 months.

CONCLUSIONS

MFC lesions accompanying MMPRT were located more medially and progressed faster than those with non-root horizontal tear. Earlier intervention such as repair of MMPRT or high tibial osteotomy, if malalignment is present, may be considered in order to prevent the progression of chondral lesion.