2015 ISAKOS Biennial Congress ePoster #1602

Midterm Results After Lateral Meniscal Allograft Transplantation with Extrusion: Subjective, Clinical and Radiological Outcomes

Sangwoo Jeon, MD, Seoul KOREA, REPUBLIC OF
Jun Sang Lee, MD, Seoul KOREA, REPUBLIC OF
Min Seok Ko, MD, Seoul KOREA, REPUBLIC OF
Inje Cho, MD, Seoul KOREA, REPUBLIC OF
Chong Hyuk Choi, MD, Seoul KOREA, REPUBLIC OF

Department of Orthopedic Surgery,Severance Hospital, Yonsei University College of Medicine, Seoul, KOREA

FDA Status Cleared

Summary: Although the incidence of the meniscal extrusion after allogenous lateral meniscus transplantation was high, extruded meniscus body has no direct effect on the clinical outcomes. There was no correlation between the degree of allografted meniscal extrusion and radiologic changes of knee.

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Abstract:

Purpose

The purpose of this study was to investigate the mid-term subjective, clinical and radiological prognosis in the patients who had meniscal extrusion on MRI after lateral meniscal allograft transplantation.

Methods

Fourty-five patients who underwent lateral meniscal allograft transplantation (MAT) using the keyhole method between 2001 and 2010 were enrolled in the study. And this MAT was for improvement of pain symptom after total or subtotal meniscectomy. The mean age of the patients who underwent operation was 35.6 (range, 19-53 years), and the mean follow-up period was 6.2 years (range, 4.1- 8.3years). All patients were evaluated with knee MRI immediately after operation. And additional knee MRI evaluation was done after 1 year to evaluate the status of grafted meniscus. The absolute values and the proportional widths of extruded lateral menisci as a ratio were measured on coronal cut image which shows maximum meniscal extrusion. The Lysholm score and visual analog scale (VAS) were used to evaluate subjective knee function. Standard knee AP X-ray and 45 degree flexed knee PA X-ray with standing position of all patients were also evaluated in terms of the alteration of osteoarthritis and joint space width.

Results

The average preoperative Lysholm score was 63.7, which increased to 88.4 at final follow-up. The average preoperative VAS was 7.3 and this decreased to 3.6 at final follow-up. Thirty eight of forty five patients (84.4%) had meniscal extrusion. The mean extruded meniscal width was 2.7mm (range, 1.2-3.7mm) and this extrusion ratio was 27.4% (range, 12.6-38.1%). The position of posterior horn was maintained without further posterior displacement or meniscal tear. Kellgren-Lawrence arthritis grade alteration was not checked in forty-one knees except 4 knees that progressed by 1 grade. The mean joint space width, which was measured as 3.8mm preoperatively and 3.7 mm at last follow-up. But there was no significant difference. No patients had increased knee joint space height. The MRI revealed allograft meniscal tears in two patients. The clinical outcomes were not correlated with the degree of allografted meniscal extrusion.

Conclusion

Although the incidence of the meniscal extrusion after allogenous lateral meniscus transplantation was high, extruded meniscus body has no direct effect on the clinical outcomes. There was no correlation between the degree of allografted meniscal extrusion and radiologic changes of knee. It is suggested that the maintenance of posterior horn in anatomical position is important for good prognosis and clinical outcome improvement. Moreover long term follow up study is also required to find out eventual effect of meniscal extrusion in terms of clinical outcome and radiologic alterations.