2015 ISAKOS Biennial Congress ePoster #1633

Concurrent Lateral Meniscal Repair and Anterior Cruciate Ligament Reconstruction Significantly Increases the Lateral Meniscal Width Percentage and Extrusion

Naoko Kashihara, MD, Okayama, Okayama JAPAN
Takayuki Furumatsu, MD, PhD, Okayama JAPAN
Shinichi Miyazawa, MD, PhD, Okayama JAPAN
Takaaki Tanaka, Tokyo JAPAN
Masataka Fujii, MD, PhD, Okayama JAPAN
Hiroto Inoue, MD, Okayama JAPAN
Toshifumi Ozaki, MD, PhD, Prof., Okayama JAPAN

Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Okayama, JAPAN

FDA Status Cleared

Summary: Concurrent lateral meniscal repair and ACL reconstruction significantly increased the lateral meniscal width percentage and extrusion, thus lateral meniscal repair and ACL reconstruction may lead to knee OA progression.

Rate:

Abstract:

INNTRODUCTION
The menisci play the crucial roles in distribute load, reduce friction, and provide joint lubrication and stabilization, thus the treatment of meniscal tear should aim at preserving meniscal tissue as much as possible. Knees subjected to anterior cruciate ligament (ACL) reconstruction have a greater incidence and severity of knee osteoarthritis (OA) than those without ACL reconstruction. Therefore, we considered that concurrent lateral meniscal repair and ACL reconstruction change the size and position of the lateral meniscus and may contribute to the incidence of knee OA. The purpose of this study was to investigate postoperative changes in lateral meniscal size after concurrent lateral meniscal repair and ACL reconstruction.

Methods

Between October 2009 and February 2014, 19 knees underwent concurrent lateral meniscus repair and ACL reconstruction. Patients with a peripheral longitudinal meniscal tear on the posterior segment were included, whereas those with a bucket-handle tear were excluded. Twenty-four normal knees were assessed. The radiographic-based lateral tibial plateau length (LTPL) and lateral tibial plateau width (LTPW) were measured. Magnetic resonance imaging (MRI) was performed before and after primary surgery. The MRI-based lateral meniscal length (LML), width (LMW), body width (LMBW), height (LMH), and extrusion (LME) were assessed. The percentage of LML to each LTPL (%LML) and the percentage of LMW to each LTPW (%LMW) were calculated. Lysholm score and side-to-side distance with the KT-2000 were used to assess anteroposterior stability.

Results

Patients were followed up for a mean of 18 months. Concurrent lateral meniscal repair and ACL reconstruction slightly increased the LMW from 28.9±2.6 to 30.0±2.8 mm. The postoperative %LMW significantly increased from 90.1±4.6% to 93.3±4.3% (P=0.021). In addition, the LME significantly increased from 0.5±0.6% to 1.1±1.0% with lateral meniscus repair (P=0.014). No significant differences in LML, %LML, LMBW, and LMH were found between the preoperative and postoperative assessments. In normal knees, LMW was 27.9±2.4 mm, %LMW was 84.8±5.2% and LME was 0.3±0.6 mm. The mean Lysholm score was 68.8±21.3 (range, 23–95) before ACL reconstruction and improved to 98.1±2.2 (range, 95–100) at the final follow-up. The mean side-to-side distance with the KT-2000 decreased 5.9 to 1.2 mm.

Discussion

Concurrent lateral meniscal repair and ACL reconstruction improved clinical outcomes. Thus, we consider that concurrent ACL injury and peripheral longitudinal tear of the lateral meniscus located on the posterior segment should be treated with concurrent lateral meniscal repair and ACL reconstruction. In addition, concurrent lateral meniscal repair and ACL reconstruction significantly increased the %LMW and LME. Meniscal extrusion is associated with knee OA and joint space narrowing. Our results suggest that lateral meniscal repair and ACL reconstruction may lead to knee OA progression by inducing the lateral meniscal extrusion.

Conclusion

Concurrent lateral meniscal repair and ACL reconstruction significantly improved clinical outcomes, and increased %LMW and LME. However, no increases in LML, %LML, LMW, LMBW, and LMH were found.