Description
Several studies have shown that the preoperative lower extremity alignment of discoid lateral meniscus shows a significant tendency to varus compared to patients with semilunar lateral meniscus, and the osteoarthritis and cartilage lesion occur more frequently in the medial and lateral compartments. However, the relationship between preoperative lower extremity alignment for discoid lateral meniscus tears and postoperative changes in lower extremity alignment and worsening of osteoarthritis has not been established.
So, the purpose of this study was to Investigate the effect of preoperative lower extremity alignment on postoperative clinical outcome, change of lower extremity alignment, and progression of osteoarthritis by comparing these parameters and clinical score.
498 Patients who had discoid lateral meniscal tears underwent arthroscopic surgery. We excluded patients who underwent the operation with ligament injury, cartilage procedure, subtotal meniscectomy and those combined with Fracture. And patients with short term follow-up was excluded. 203 cases were included and we divided into three groups according to preoperative HKA angle. So, those below -2 degrees were varus group, between -2 degrees and 2 degrees were neutral group, and those above 2 degrees were valgus group.
Mechanical hip knee ankle angle, medial proximal tibial angle, and lateral distal femoral angle were measured on lower extremity x-ray scanogram. Lateral joint space was measured on Rosenburg view x-ray. Tegner score, Lysholm score, and HSS score was used to evaluate clinical outcomes.
In all three groups, the postoperative Hip-knee ankle angle showed a statistically significant valgus change compared to preoperation. And, In all three groups, the postoperative Lateral joint space significantly reduced compared to preoperation. When comparing pre- and post-operative differences of HKA angle and lateral joint space, there were no statistically significant differences between the three groups. There was no statistically significant difference in pre- and post-operative medial proximal tibial angle in all three groups. Also, there was no statistically significant difference in pre- and post-operative lateral distal femoral angle in all three groups. There was no statistically significant difference in postoperative clinical outcome between the three groups.
In discoid lateral meniscus patients, Postoperative alignment of the lower extremity was significantly changed to valgus and Postoperative lateral joint space was also significantly reduced. MPTA and LDFA was not significant, and there was not failure or 2nd operation. When divided into three groups according to preoperative lower extremity alignment, the postoperative difference among three groups in lower extremity alignment and lateral joint space was not significant, and there was no worsening of clinical score or osteoarthritis in the valgus group compared to the other two groups
