Characterization of grade 3 MRI signals following meniscal repair

Objective To explore the diagnostic value of grade 3 MRI signals in assessment of meniscal healing by comparing the differences in grade 3 MRI signals between healed and unhealed meniscus.Methods From March 2007 to December 2008,39 patients (41 menisci) received arthroscopic repair of the ruptured meniscus.They were 29 men and 10 women,with a mean age of 25.8 ± 6.8 years.They underwent MRI examination and second arthroscopy at 17.7 ± 3.3 months postoperation.According to the results of the second arthroscopy,they were divided into a healed group (27 cases and 29 menisci) and an unhealed group (12 cases and 12 menisci).The depth,length,width and intensity of grade 3 MRI signals at the repaired site were compared between the 2 groups.Results The grade 3 signals were still observed in 79.3％ (23/29) of the menisci in the healed group.The depth ratio (postoperative/preoperative) in the unhealed group (PD:81.0％ ± 41.3％,T2:62.8％ ± 42.5％) was significantly higher than that (PD:32.3％ ± 33.3％,T2:21.3％ ±33.7％) in the healed group (P ＜0.05).The width (2.2 ± 0.8 mmversus 1.0 ± 0.6 mm) and intensity in the unhealed group was significantly higher than in the healed group(P ＜ 0.05).Besides,the signalintensityofthehealedmeniscuswassignificantlylowerthanthepreoperativelevel(P ＜0.05).No significant differences were found in terms of the signal length between the 2 groups(P ＞ 0.05).Conclusions Changes in the width and intensity of grade 3 MRI signals following meniscal repair helps a lot the clinical diagnosis of healed and unhealed menisci.The decreased width and intensity of grade 3 MRI signals indicate healing of the meniscus. Key words: Menisci, tibial;  Magnetic resonance imaging;  Arthroscopy;  Signal