123. ARTHROSCOPIC TREATMENT OF THE DISCOID MENISCUS IN CHILDREN: CLINICAL AND MRI OUTCOMES

Abstract

Purpose of the study: For symptomatic discoid meniscus, the treatment of choice in children is arthroscopic meniscoplasty. The treatment of associated meniscal lesions remains a subject of debate. The purpose of our work was to evaluate our results with arthroscopic meniscoplasty associated with meniscal repair as needed and the findings of the systematic postoperative MRI.

Material and methods: This was a retrospective series of patients treated by one operator. There were 23 discoid menisci (21 patients) treated from 2004 to 2007 with arthroscopic meniscoplasty followed by a complementary procedure depending on the residual meniscus: abstention if there was no associated lesion, suture or reinsertion for reparable lesions, partial meniscectomy for non-reparable lesions. The Lysholm and Tegner scores, plain x-rays, and MRI were obtained systematically.

Results: Mean age at surgery was 9.8 years. The Watanabe classification was I:9, II:9, III:5. Arthroscopy revealed 15 lesions, including 11 longitudinal tears. Meniscoplasty was performed in 9 cases alone, associated with partial meniscectomy in 6 and with repair in 8 (5 cases of disinsertion and 3 tears). Mean follow-up was 37.1 months. The mean postoperative Lysholm was 87.9, the Tegner 5.9. Outcome was considered satisfactory or very satisfactory by 90% of patients. MRI failed to reveal any signs of chondral degeneration or meniscal tear. There were however four cases of high intensity intra-meniscal signals and one meniscal cyst. Mean measurements of the residual meniscus were: anterior segment 8.6 mm thickness and 2.6 mm height; middle segment 5.5 and 2.3 mm; posterior segment 5.8 and 3.0 mm. One case of osteochondritis of the lateral condyle was noted postoperatively.

Discussion: To our knowledge, there is no other study evaluating the outcome of discoid meniscus surgery with postoperative MRI. There have been few reports concerning meniscoplasty then repair. This approach spares meniscal tissue, essential for children. We obtained good clinical results and patient satisfaction. At the MRI, the residual meniscus had a morphology close to normal. There were no signs of tears. The high intensity signals occurred in patients with good outcome.

Conclusion: Arthroscopic meniscoplasty associated with repair or partial meniscectomy as needed appears to be a good therapeutic solution for discoid meniscus in children.