Panos Joseph A, Devitt Brian M, Feller Julian A, Klemm Haydn J, Hewett Timothy E, Webster Kate E
Mayo Clinic, Rochester, Minnesota, USA.
OrthoSport Victoria Research Unit, Epworth HealthCare, Melbourne, Victoria, Australia.
Orthop J Sports Med. 2021 Sep 13;9(9):23259671211023512. doi: 10.1177/23259671211023512. eCollection 2021 Sep.
After anterior cruciate ligament (ACL) reconstruction (ACLR), changes in the appearance of the ACL graft can be monitored using magnetic resonance imaging (MRI).
The purpose of this study was to evaluate and compare the MRI signal intensity (SI) of hamstring and quadriceps tendon grafts during the first postoperative year after ACLR. As a secondary aim, the relationship of SI to clinical and anatomic measurements was analyzed.
Cohort study; Level of evidence, 2.
A total of 78 patients who underwent ACLR with an autologous graft were reviewed; 55 received hamstring grafts and 23 received quadriceps tendon grafts. At 3 and 9 months postoperatively, 3-T MRI was performed using a dedicated knee coil, and the median SI of the intra-articular ACL graft was measured on sagittal-plane images. Postoperative lateral radiographs were analyzed to determine medial and lateral posterior tibial slope (PTS). Side-to-side difference in anterior knee laxity between injured and uninjured limbs was measured at 6 and 12 months postoperatively.
The median SI of quadriceps grafts was significantly greater than hamstring grafts at 3 months after ACLR ( = .02). Between 3 and 9 months, the median SI of quadriceps grafts decreased ( < .001), while that of hamstring grafts did not significantly change ( = .55). The lateral PTS was significantly correlated with median SI measurements at 3 and 9 months such that greater lateral PTS values were associated with greater median SI. The side-to-side difference in anterior knee laxity decreased for the quadriceps group ( = .04) between 6 and 12 months but did not change for the hamstring group ( = .88).
The median SI of quadriceps grafts significantly decreased on MRI between 3 and 9 months after ACLR, while the median SI of hamstring grafts did not significantly change. The change in MRI appearance of the quadriceps grafts was paralleled by a reduction in anterior knee laxity between 6 and 12 months after surgery. In the absence of standardized imaging techniques and imaging analysis methods, the role of MRI in determining graft maturation, and the implications for progression through rehabilitation to return to sport, remain uncertain.
在前交叉韧带（ACL）重建（ACLR）术后，可使用磁共振成像（MRI）监测ACL移植物的外观变化。
本研究旨在评估和比较ACLR术后第一年绳肌和股四头肌肌腱移植物的MRI信号强度（SI）。作为次要目的，分析SI与临床和解剖学测量值之间的关系。
队列研究；证据等级，2级。
回顾了78例行自体移植物ACLR的患者；55例接受绳肌移植物，23例接受股四头肌肌腱移植物。术后3个月和9个月，使用专用膝关节线圈进行3-T MRI检查，并在矢状面图像上测量关节内ACL移植物的中位SI。分析术后的侧位X线片以确定胫骨后内侧和外侧坡度（PTS）。在术后6个月和12个月测量受伤肢体与未受伤肢体之间前膝松弛度的左右差异。
ACLR术后3个月，股四头肌移植物的中位SI显著高于绳肌移植物（P = 0.02）。在3至9个月之间，股四头肌移植物的中位SI下降（P < 0.001），而绳肌移植物的中位SI没有显著变化（P = 0.55）。外侧PTS与3个月和9个月时的中位SI测量值显著相关，外侧PTS值越大，中位SI越大。股四头肌组在6至12个月之间前膝松弛度的左右差异减小（P = 0.04），而绳肌组没有变化（P = 0.88）。
ACLR术后3至9个月，股四头肌移植物的中位SI在MRI上显著下降，而绳肌移植物的中位SI没有显著变化。股四头肌移植物MRI表现的变化与术后6至12个月前膝松弛度的降低平行。在缺乏标准化成像技术和成像分析方法的情况下，MRI在确定移植物成熟度以及对康复进程以恢复运动的影响方面仍不确定。
