Comparative postural stability in patients with lateral meniscus versus medial meniscus tears.

BACKGROUND

Types of mechanoreceptors may differ between the medial and lateral menisci, suggesting that postural stability may differ between patients with medial and lateral meniscus tears. However, to date, postural stability has not been compared in patients with medial and lateral meniscus tears. This study used stabilometry to compare postural stability in patients with medial and lateral meniscus tears.

METHODS

Postural stability and thigh muscle strength were assessed in 24 patients with medial and 18 patients with lateral meniscus tears. Postural stability was determined by measuring the anteroposterior (APSI), mediolateral (MLSI), and overall (OSI) stability indices using stabilometry. Maximal torque (60°/s) of the quadriceps and hamstring was evaluated using an isokinetic testing device.

RESULTS

The three stability indices, OSI, APSI, and MLSI, in both involved and uninvolved knees were all significantly greater in patients with lateral than with medial meniscus tears. (P<0.001 for all OSI, APSI, and MLSI in both involved and uninvolved knees, except for P=0.005 for MLSI of involved knees). In patients with medial meniscus tears, both OSI (1.4±0.4 vs. 1.1±0.4, P=0.037) and MLSI (0.9±0.3 vs. 0.8±0.3, P=0.041) were significantly higher on the injured than the uninjured side. In patients with lateral meniscus tears, none of the stability indices differed significantly between injured and uninjured knee joints.

CONCLUSION

Postural stability of both the injured and uninjured knee joints was poorer in patients with lateral than with medial meniscus tears.