MRI signal changes in completely healed meniscus confirmed by second-look arthroscopy after meniscal repair with bioabsorbable arrows

Abstract

This study evaluated the MRI signal characteristics and MRI diagnostic accuracy in identifying completely healed menisci repaired with bioabsorbable arrows. A total of 34 patients (38 menisci), with a mean age of 26.0 years, underwent arthroscopic meniscal repair with bioabsorbable arrows and concomitant anterior cruciate ligament (ACL) reconstruction. Of the 34 patients, 27 were male and 7 were female. Of the 38 menisci, 27 were medial and 11 were lateral. Second-look arthroscopy was performed for each patient while taking out the hardware for ACL reconstruction of the tibial side to evaluate the healing status of the repaired menisci. Postoperative MRI was done 2 days before or after second-look arthroscopy. Sagittal T1, T2 and PD images and coronal T2 and PD images were used as the main diagnostic serials. Second-look arthroscopy showed that surfaces of the repaired sites of all 38 menici were almost smooth. In all 38 cases the tail ends of meniscus arrows disappeared and in four patients new overlying injury of compartmental cartilage at the repaired side was detected. MRI results revealed that different serials had different diagnostic accuracy. Sagittal: T1 28.9%, PD 34.2%, T2 60.5%. Coronal: PD 36.8%, T2 65.8%. The double sides Grade 3 signal had a higher proportion in saggital T1 and PD serials, 47.4 and 39.5%, respectively, while lower in sagittal and coronal T2 serials, both 5.3%. MRI diagnostic accuracy was correlated positively with the follow-up time (P< 0.05). MRI has its limitation in evaluating the status of menisci repaired with bioabsorbable arrows, especially for PD and T1 serials. T2 serials have higher diagnostic accuracy than other serials. MRI diagnostic accuracy can be improved by prolonging follow-up time and might be improved by further classifying Grade 3 signal in terms of signal intensity and the shape of the signal margin.

Relationship between MRI T1rho value and histological findings of intact and radially incised menisci in microminipigs

“…When the postoperative sutured meniscus is assessed using MRI, it is difficult for conventional MRI to distinguish the healing process from retear, when high intensity change exists at the repair site . The data of this study suggest that T 1 rho mapping would be useful for evaluating the healing process of injured menisci.…”

Magnetic Resonance Imaging is not suitable for interpretation of meniscal status ten years after arthroscopic repair

“…A significant reduction (but not disappearance) of this hypersignal occurred from three to 12 months, which suggested that the meniscal healing process lasted for at least 12 months. Miao et al [12] evaluated the MRI signal characteristics and MRI diagnostic accuracy in identifying completely healed repaired menisci. A second look arthroscopy confirmed complete healing.…”

“…Conventional MRI is an accurate method for diagnosing meniscal derangements but it is less reliable in the postoperative assessment of meniscal repairs in the short to mid-term [9,10], particularly as a scar in a properly healed meniscus can mimic the signal seen in meniscal tears [11,12]. Hoffelner and al.…”

Current status of second-look arthroscopy after meniscal allograft transplantation: review of the literature

“…Intra-substance degeneration could be seen in the normal menisci of older patients, so it could be difficult to distinguish from normal findings. Finally, MRI could not be employed for the dynamic evaluation of meniscal allografts utilizing range of motion [21,31,32]. Therefore, this study intended to report the need and role of second-look arthroscopy as an objective evaluation method after MAT.…”