Adjustable-Loop Devices Promote Graft Revascularization in the Femoral Tunnel After ACL Reconstruction: Comparison With Fixed-Loop Devices Using Magnetic Resonance Angiography

Abstract

Background: Hamstring tendon grafts are usually fixed in anterior cruciate ligament (ACL) reconstruction using either an adjustable-loop device (ALD) or a fixed-loop device (FLD). The contact area between the graft and the tunnel wall is different between the 2 devices. Purpose: To determine using magnetic resonance angiography (MRA) whether ALD and FLD result in different blood flow of the graft in the femoral tunnel during the early postoperative period. Study Design: Cohort study; Level of evidence, 3. Methods: Between 2008 and 2018, a total of 42 patients (17 men and 25 women) underwent MRA at 3 months after ACL reconstruction. All surgical procedures were performed using semitendinosus tendon autografts folded into 4 strands. Overall, 23 patients underwent the FLD procedure and 19 patients underwent the ALD procedure. The signal intensity of the superior portion of the graft in the femoral tunnel was evaluated using transverse MRA images perpendicular to the femoral tunnel axis. Results: MRA images showed high signal intensity in the superior portion of the graft in the femoral tunnel in 94.7% and 60.9% of the ALD patients and FLD patients, respectively, a statistically significant difference ( P = .03). Conclusion: MRA images at 3 months after surgery revealed that blood flow reached the superior end of the tendon graft in the femoral tunnel in more patients who underwent ACL reconstruction with an ALD compared with an FLD.

Fixed-loop vs. adjustable-loop cortical button devices for femoral fixation in ACL reconstruction – a systematic review and meta-analysis

“…Therefore, the ALDs were designed with an adjustable loop allowing for loop re-tensioning after graft insertion and adjustment of the loop’s length [ 39 ]. This provides surgical advantages that potentially lead to reduced bone removal [ 27 ], reduced femoral tunnel widening [ 14 , 25 ], and improved graft healing [ 23 ]. Biomechanical studies found ALDs to be inferior to FLDs in terms of maximum displacement after cyclic loading, ultimate load to failure, and stiffness [ 7 , 8 , 29 , 38 ].…”

Computed Tomography Imaging Results of Single Band Anterior Cruciate Ligament Reconstruction: A Retrospective Study Comparing Fixed- and Adjustable-Length Loop Cortical Fixation on the First Day After Surgery

“…However, to our knowledge no clinical study has reported the postoperative tunnel lling of the RIGIDLOOP device. Moreover, recent studies have indicated that gap distances are positively correlated with postoperative femoral tunnel widening and that they may affect revascularization after ACLR based on CT and MRI image ndings [2,14,16,17,[19][20][21]. These ndings suggest that the large space may affect the prognosis of patients.…”

“…In previous studies, investigators used magnetic resonance imaging (MRI) to evaluate the femoral tunnel and graft [2,3,16,17]. Ahmet.et al reported that the gap distance was 4.6 ± 0.3 mm and 9.5 ± 1.6 mm in the groups in which toggle loc with zip loop femoral xation ALDs and ENDOBUTTON CL xation loop devices were used, respectively [3].…”

Both Adjustable and Fixed Loop Hamstring Tendon Graft Fixation Have Similar Clinical and Patient-Reported Outcomes in Anterior Cruciate Ligament Reconstruction

“…ALDs have several advantages over FLDs. The tunnel size of ALDs is shorter, and drilling of exact tunnel length is not required as opposed to FLD, 34 resulting in a greater contract area (12% to 15%) between the superior tip of the graft (tendon) and the superior end of the tunnel wall in ALD than FLD. Kamitani et al.…”