Adjustable Loop Cortical Suspension Devices Research Articles

Does retensioning of adjustable-loop cortical suspension devices improve performance: A systematic review and meta-analysis

Objectives: To date, there is conflicting evidence when comparing fixed-loop cortical suspension devices (FLDs) to adjustable-loop devices (ALDs). Some studies indicate that ALDs are inferior to FLD in regard to displacement and failure load while others show that they are biomechanically similar. The purpose of this study is to use a meta-analysis of biomechanical data to compare FLDs to ALDs with and without retensioning. It is hypothesized that retensioning the ALD will allow these devices to be biomechanically equivalent to the FLD in total unloaded displacement and failure load. Materials and Methods: This study sought to identify all biomechanical studies that compared fixed loops to ALD. A meta-analysis was performed to find the standardized mean difference with retensioning as a covariate. Results: The analysis of isolated tests showed that retensioning reduced the cyclic ALD displacement in comparison to non-retensioned ALD; however, both the ALD with and without retensioning had significantly higher cyclical displacement and significantly lower failure load compared to the FLD. In the meta-analysis of the animal model data, there was no significant difference between the ALD with retensioning and the FLD. Conclusion: This analysis suggests that retensioning reduces displacement of an ALD, with displacements measured in animal bone testing showing no significant difference as compared to FLD. However, in the device-only model, the ALD with retensioning and the ALD without retensioning had significantly higher cyclical displacement and significantly lower load to failure compared to the FLD. These data suggest that retensioning may be beneficial. However, there is significant heterogeneity in the pooled studies which limit the strength of this conclusion.

Autologous Single Semitendinosus Anatomical Posterolateral Corner Reconstruction With Adjustable-Loop Cortical Suspension Devices

We present our surgical technique for the reconstruction of the posterolateral corner of the knee. It is a tibia- and fibular-based reconstruction technique. Most of these procedures require the use of 2 tendons (autograft or allograft). In our technique, a single semitendinosus tendon is required, making the procedure more suitable if the surgeon prefers the use of autograft or when there is no access to a tissue bank. This is even more important in the setting of multiligament knee injuries. The most defining feature of this modification is the possibility of achieving the desired graft tension in a progressive and independent way, due to the use of 3 adjustable-loop cortical suspension devices.

Does loop length change after anterior cruciate ligament reconstruction with adjustable loop cortical suspension device?: Observation of the hamstring graft completely filling the femoral tunnel

PurposeThe adjustable loop cortical suspension device (ALD) is a useful femoral fixation device in anterior cruciate ligament (ACL) reconstructions, but the possibility of loosening has been suggested. The purpose of this study was to evaluate the elongation of an adjustable loop and the position of the hamstring graft inside the femoral socket.MethodsThe subjects were 33 patients who underwent ACL reconstruction with a hamstring tendon. The graft was fixed using ALD and completely filled the femoral socket. Magnetic resonance images were taken one week and one year after the operation. The loop length, femoral socket length, and graft length inside the socket were measured and statistically compared with the clinical outcomes.ResultsThe loop length one week after surgery was 18.9 ± 4.4 mm, and 1 year after surgery was 19.9 ± 4.5 mm (P < 0.001). The gap between the top of the graft and femoral socket was 0.9 ± 1.8 mm one week after surgery and 1.3 ± 1.7 mm one year after surgery (P = 0.259). At one week post-operation, a gap was found in nine patients (27.3%). The loop length and gap did not strongly correlate with clinical findings.ConclusionACL reconstruction using ALD showed a gap between the graft and femoral socket at the one week post-operation mark in 27.3% of participants. One year after the surgery, there were cases where the gap increased and/or decreased, but the elongation of the loop was 1 mm on average. Our findings suggest that ALD is clinically safe to use; however, has the possibility of initial loop elongation and non-uniform changes.Level of evidenceIV.

Adjustable-loop cortical suspension device for posterolateral corner reconstruction in the setting of fibular avulsion fracture: a case series and novel technique description.

A novel technique using an adjustable-loop cortical suspension toggle device for reduction of a fibular head avulsion fracture (arcuate fracture) in posterolateral corner (PLC) reconstruction is described. Results of clinical follow-up are presented. 9 patients were retrospectively identified who underwent posterolateral corner reconstruction using an adjustable-loop cortical suspension toggle device. Radiographic examination was used to evaluate the successful healing of the avulsed fibular head fragments post-operatively. 7 patients reported satisfactory results with their clinical outcome with no feelings of knee instability or objective instability on exam at final follow-up. Post-operative radiographs obtained > 6months following reconstruction demonstrated well reduced and healed fracture in 5 of 6 patients, with 1 patient demonstrating maintained reduction but incomplete fracture union at 6months. This novel surgical technique for PLC reconstruction with an avulsed fibular head fracture is a viable alternative to previously described methods. The majority of patients report subjective satisfaction with a stable knee post-operatively. IV.

Comparison Between Early and Late Retensioning of an Adjustable-Loop Cortical Suspension Device During Hamstring ACL Reconstruction.

Background:Biomechanical studies have demonstrated significant loosening of the adjustable-loop device as compared with the fixed-loop device used in anterior cruciate ligament reconstruction. Retensioning of the adjustable loop has been recommended; however, the timing of the retensioning is unknown.Hypothesis:Early (ER) and late retensioning (LR) will show similar gapping between the femoral tunnel and graft on follow-up magnetic resonance imaging (MRI) and similar clinical outcomes.Study Design:Cohort study; Level of evidence, 3.Methods:This study included 101 patients who underwent hamstring anterior cruciate ligament reconstruction using the adjustable-loop device for femoral fixation between June 2016 and January 2018. All patients a had follow-up MRI on postoperative day 1. Patients with revision surgery and those with reinjury after reconstruction were excluded. In the ER group, retensioning and knot tying of the initially tightened adjustable loop were performed after the flip of the button and before the graft was fixed at the tibia. In the LR group, retensioning and knot tying were performed after initial tightening of the adjustable loop and graft fixation at the tibial side. The tunnel-graft gap measured on multiplanar reformatted images of MRI scans was compared between the groups, as were clinical outcomes.Results:The mean age of the patients at the time of surgery was 30.3 years (range, 14-61 years). ER and knot tying were performed in 56 patients and LR and knot tying in 45. Preoperative characteristics of the 2 groups showed no significant differences. The mean ± SD tunnel-graft gap was 1.5 ± 2.0 mm in the ER group and 5.4 ± 4.0 mm in the LR group (P < .001). There were no significant differences in clinical outcomes between the groups.Conclusion:ER and knot tying demonstrated less tunnel-graft gap than that of LR. However, there were no differences in clinical outcomes according to the timing of retensioning.

FIXED VERSUS ADJUSTABLE LOOP CORTICAL SUSPENSION DEVICES IN ARTHROSCOPIC ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

Background: Anterior cruciate ligament reconstruction has remained the gold (ACL) standard for ACL injuries, especially for young individuals and athletes expose to high level sporting activities aiming to return his or her preinjury level of activity. Cortical suspensory femoral fixation is commonly performed for graft fixation to the femur in anterior cruciate ligament (ACL) reconstruction using hamstring tendons. Aim of the work: The aim of the work was to compare the clinical results between fixed and adjustable loop cortical suspension devices in arthroscopic ACL reconstruction using the Lysholm Knee Scoring Scale after 12 months postoperatively. Methods: This study included a total of sixty patients who underwent transportal arthroscopic ACL reconstruction using hamstring tedon autograft from November 2016 to December 2017. For femoral graft fixation, a fixed-length loop device was used in 30 patients (fixed-loop group) and an adjustable-length loop device was used in 30 patients (adjustable-loop group) randomly.For tibial graft fixation, interference screw was used for all patients. Results: The present study shows that there was no statistically significant difference between the two groups regarding the Lysholm score with highly statistically significant difference between preoperative and postoperative Lysholm score in each group separately. Conclusions: Both fixed loop and adjustable loop devices in ACL reconstruction provided good clinical outcomes but without significant statistical difference between both groups from the clinical point of view postoperatively using the Lysholm score.

Adjustable Loop Femoral Cortical Suspension Devices for Anterior Cruciate Ligament Reconstruction: A Systematic Review.

Anterior cruciate ligament (ACL) injury is a common sports injury. Symptomatic knee instability after this injury is usually treated operatively through ACL reconstruction. The surgery involves a tendon graft being fixed in bony tunnels drilled through femur and tibia. The fixation of the graft is of critical importance to achieving good results. One of the commonest devices used to fix the graft in the femoral bony tunnel is a fixed loop cortical suspensory device. More recently, adjustable loop cortical suspension devices have been introduced, and have gained popularity for ACL reconstruction. These allow for adjusting the length of the suspension loop after insertion. There is currently much debate concerning whether the adjustable loop devices are superior or inferior to the fixed loop devices. To critique and review the current biomechanical and clinical evidence on the use of adjustable loop devices in hamstring ACL reconstruction. To our knowledge, there have been no previous reviews of this topic. Systematic review. This systematic review was conducted in accordance with PRISMA. Five databases were searched using multiple search terms and MeSH terms where possible. The following limits were applied: papers published in English and papers published in the last 21years. Eleven laboratory and six clinical studies were reviewed. The laboratory-based studies have frequently shown elongation of adjustable loop devices to more than 3mm under loading protocols, whereas the clinical studies have not shown any significant differences between the patients with fixed loop and the ones with adjustable loop devices. This review shows a discrepancy between laboratory-based and clinical studies. The review of clinical studies in our paper would give future researchers confidence and act as a prompt to construct randomised clinical trials to investigate these devices further. We feel that more robust clinical randomised studies and trials are needed to evaluate these new devices.

Comparison of Postoperative Tunnel Widening After Hamstring Anterior Cruciate Ligament Reconstructions Between Anatomic and Nonanatomic Femoral Tunnels

To evaluate the effect of the location of the femoral tunnel on 3-dimensional (3D) computed tomography (CT) upon the postoperative tunnel widening after anterior cruciate ligament (ACL) reconstructions. Inclusion criteria were patients who underwent hamstring ACL reconstructions using an adjustable-loop cortical suspension device, underwent 3D CT at the day after surgery, and were followed for a minimum of 2 years after surgery. Exclusion criteria were patients with combined ligament injury and reinjury after reconstruction. Using 3D CT, the center of the femoral tunnel aperture was located on a standardized grid system. The center of the ACL footprint was defined from the literature. The femoral tunnel location was classified as anatomic if it located within 2 standard deviations of the center position. If it was outside the 2 standard deviations, the tunnel was classified as nonanatomic. The patients were divided into either anatomic or nonanatomic groups. Femoral tunnel angles on both sagittal and coronal planes were measured. Both femoral and tibial tunnels measured on anteroposterior and lateral radiographs at immediate postoperative day and at 2 years after surgery. Postoperative knee stability and patient-reported outcomes were evaluated. There were 37 patients in anatomical group and 52 patients in nonanatomical group among enrolled 87 patients. There were no differences in demographics between the 2 groups. There were no differences in the femoral tunnel angles and postoperative tunnel widening between the 2 groups. A higher position correlated to the femoral tunnel widening at 2 years postoperatively. Postoperative knee stability and patient-reported outcomes showed no statistically significant differences between the 2 groups. There was no significant difference in postoperative tunnel widening or clinical outcomes between anatomic and nonanatomic femoral tunnel location after hamstring ACL reconstructions. A higher position correlated to the femoral tunnel widening at 2 years postoperatively. Level III, Retrospective comparative study.

Radiologic and Clinical Outcomes After Hamstring Anterior Cruciate Ligament Reconstruction Using an Adjustable-Loop Cortical Suspension Device With Retensioning and Knot Tying

To report magnetic resonance imaging (MRI) findings and clinical outcomes after anterior cruciate ligament reconstruction using an adjustable-loop device (ALD) with retensioning and knot tying. The inclusion criteria were patients who underwent hamstring anterior cruciate ligament reconstruction using an ALD with retensioning and knot tying between May and December 2015 and were followed up for a minimum of 2years. The exclusion criteria were patients with combined ligament injury, revision surgery, or reinjury after reconstruction. After initial tightening of the adjustable loop, retensioning and knot tying were performed and the graft was fixed at the tibia. Multiplanar reformatted images of 3-T MRI scans were obtained on the immediate postoperative day and at 6months after surgery to measure the gap between the top of the graft and the top of the femoral tunnel (i.e., tunnel-graft gap). Differences in the tunnel-graft gap between the immediate postoperative day and 6months after surgery (i.e., gap difference) were calculated and correlated with knee stability and functional outcomes. Thirty-six patients were enrolled in this study. The mean tunnel-graft gap was 2.1 ± 2.8mm on the immediate postoperative day and 4.6 ± 3.5mm at 6months after surgery (P < .001). The mean gap difference was 2.5 ± 2.0mm. The mean KT-1000 measurement was 1.5 ± 2.2mm, and mean Lysholm score and Tegner activity scale score were 93.6 ± 5.5 and 5.6 ± 1.5, respectively. The gap difference correlated negatively with the follow-up Lysholm score (P= .004); however, knee stability and the Tegner activity scale score were not correlated. Although the ALD was secured by retensioning and knot tying, MRI showed that the graft was not fully inserted in some patients and the tunnel-graft gap increased at 6months' follow-up. The increase in the tunnel-graft gap did not correlate with knee stability or the Tegner activity scale score but correlated negatively with the Lysholm score. Level IV, therapeutic case series.

Hamstring Anterior Cruciate Ligament Reconstruction Using an Adjustable-Loop Cortical Suspension Device: Immediate Postoperative Magnetic Resonance Imaging.

The purpose of this study is to determine whether the hamstring grafts are fully inserted into the femoral tunnel with the adjustable loop using immediate postoperative magnetic resonance imaging (MRI) after anterior cruciate ligament (ACL) reconstructions. A total of 62 consecutive patients underwent hamstring ACL reconstruction using an adjustable-loop cortical suspension device for the femoral fixation and the Intrafix sheath and screw for the tibial fixation. Multiplanar reformatted images of 3-T MRI scans were obtained at the 1st postoperative day before weight bearing is initiated in all patients to evaluate the gap (the tunnel-graft gap) between the top of the hamstring graft and top of the femoral tunnel. Postoperative MRI scans showed that the tunnel-graft gap was 1.5 ± 2.7 mm (range, 0-12 mm). In 43 (69.4%) patients, there was no gap between the top of the femoral tunnel and hamstring graft. In 19 (30.6%) patients, there was a gap between the tunnel and graft, and nine patients demonstrated a tunnel-graft gap greater than 5 mm. Immediate postoperative MRI scans demonstrated that an adjustable-loop cortical suspension device may not pull the hamstring graft completely into the femoral tunnel.

Comparison of Clinical and Radiologic Outcomes and Second-Look Arthroscopic Findings After Anterior Cruciate Ligament Reconstruction Using Fixed and Adjustable Loop Cortical Suspension Devices

To compare clinical and radiological outcomes, including tunnel widening, and to evaluate graft status by second-look arthroscopy after anterior cruciate ligament (ACL) reconstruction using 2 different femoral cortical suspension devices (fixed and adjustable loop). Seventy-nine patients were included for this study. The patients were divided into 2 groups, 41 patients of fixed loop group (EndoButton) and 38 patients of adjustable loop group (TightRope). The Tegner activity, Lysholm knee score, Lachman test, and pivot-shift test were compared between the 2 groups. Anterior stress radiographs and femoral tunnel widening on plain radiographs were also compared. Twenty-seven patients (66%) in the EndoButton group and 21 patients (55%) in the TightRope group underwent the second-look arthroscopy. At the final follow-up, the mean Tegner activity, Lysholm, and International Knee Documentation Committee scores were improved in both groups and there were no statistically significant differences (5.1 ± 1.6 and 5.5 ± 2.1, P= .312; 90.4 ± 7.8 and 91.0 ± 6.5, P= .525; and 87.4 ± 6.7 and 88.7 ± 5.3, P= .127, respectively). There were no statistical significances in the both groups in terms of Lachman test and pivot-shift tests (P= .392, .559) as well as anterior stress radiographs (mean 3.2 ± 1.4mm and 2.9 ± 1.1mm, P= .343). Moreover, radiologic measurements comparing femoral tunnel widening at proximal and distal half also showed no significant differences (P= .540 and .412 on anteroposterior view; P= .254 and .437 on lateral view). In the second-look arthroscopy findings for graft tear and synovial coverage, there were no significant differences (P= .784 and .897). Both fixed loop and adjustable loop devices in ACL reconstruction provided good clinical and radiological outcomes. In patients with both devices, femoral tunnel widening at proximal and distal portion have no significant differences after ACL reconstruction. Moreover, second-look arthroscopy revealed no significant differences in terms of synovial coverage and rupture of the graft. Level II, prospective comparative study.

Fixed- Versus Adjustable-Loop Femoral Cortical Suspension Devices for Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Biomechanical Studies.

Background:Fixed- and adjustable-loop femoral cortical suspension devices are commonly used for femoral graft fixation during anterior cruciate ligament reconstruction (ACLR).Purpose:To compare the biomechanical results of fixed- versus adjustable-loop femoral cortical suspension devices in studies simulating ACLR with an isolated device and/or specimen setup using porcine femora and bovine flexor tendons.Study Design:Systematic review.Methods:Two independent reviewers searched PubMed, Embase, and the Cochrane Library databases to find studies comparing the biomechanical strength of fixed- and adjustable-loop cortical suspension devices for ACLR with isolated device and/or specimen setups using porcine femora and bovine flexor tendons. Studies that compared both devices with similar biomechanical methods were included. Data extracted included displacement during cyclic loading, ultimate load to failure, and mode of failure of the different cortical suspension devices for ACLR.Results:Six studies were identified that met the inclusion criteria, including a total of 76 fixed-loop devices and 120 adjustable-loop devices. Load to failure was significantly different (P < .0001), with the strongest fixation device being the ToggleLoc with ZipLoop adjustable-loop device (1443.9 ± 512.3 N), compared with the Endobutton CL fixed-loop device (1312.9 ± 258.1 N; P = .04) and the TightRope RT adjustable-loop device (863.8 ± 64.7 N; P = .01). Cyclic displacement was significantly different, with Endobutton CL (3.7 ± 3.9 mm) showing the least displacement, followed by ToggleLoc with ZipLoop (4.9 ± 2.3 mm) and TightRope RT (7.7 ± 11.1 mm) (P < .0001). Mode of failure was statistically different between the 3 groups (P = .01), with suture failure accounting for 83.8% of TightRope RT devices, 69.4% of ToggleLoc with ZipLoop devices, and 60.3% of Endobutton CL devices.Conclusion:Current biomechanical data suggest that the ToggleLoc with ZipLoop device is the strongest fixation device at “time zero” in terms of ultimate load to mechanical failure. However, the Endobutton CL device demonstrated the least cyclic displacement, which may be a more clinically applicable measure of device superiority.

Mechanical Properties of an Adjustable-Loop Cortical Suspension Device for Anterior Cruciate Ligament Reconstruction.

Background:Various biomechanical properties of adjustable-loop cortical suspension devices have been observed among previous studies in which different experimental conditions were used to test each of these devices. However, no studies have investigated the biomechanical properties of single adjustable-loop cortical suspension devices under different cyclic loading protocols. It is necessary to clarify the problems associated with using this device and detect the best method of using it in the clinical setting.Hypothesis:The elongation of the loop of an adjustable-loop cortical suspension device with cyclic loading would be smaller with (1) an increase in the lower force limit and (2) lower speeds of cyclic loading.Study Design:Controlled laboratory study.Methods:Eighteen anterior cruciate ligament (ACL) adjustable-loop cortical suspension devices were tested under the following 3 cyclic loading protocols in a device-only model. Protocol A included cyclic loading between 10 and 50 N at 50 mm/min for 500 cycles. The upper force limit was then increased by 25-N increments every 500 cycles up to 250 N, for a total of 4500 cycles. Protocol B included cyclic loading between 30 and 50 N at 50 mm/min for 500 cycles. The upper force limit was then increased to 250 N, for a total of 4500 cycles, in the same manner as protocol A. Protocol C included cyclic loading between 30 and 50 N at 25 mm/min for 500 cycles. The upper force limit was then increased to 250 N, for a total of 4500 cycles, in the same manner as protocol A.Results:The elongation after 4500 cycles was 36.1, 18.5, and 8.6 mm for protocols A, B, and C, respectively. There were significant differences among the 3 protocols, with protocol C showing the smallest elongation with cyclic loading. The elongation in each group progressed with each 25-N cyclic load increment.Conclusion:The adjustable-loop cortical suspension device showed a smaller elongation of the loop with increases in the lower force limit and with lower cyclic loading speeds.Clinical Relevance:Care should be taken during rehabilitation after anatomic ACL reconstruction using adjustable-loop cortical suspension devices with a low initial tension at graft fixation. Slow and less intense exercises may be more desirable in the early stages of healing.

Comparative study on fixed versus adjustable-length loop device for femoral fixation of graft in anterior cruciate ligament reconstruction

Aims and Objectives: Cortical suspension devices have been widely used in ACL reconstruction for femoral side graft fixation. Fixed-length and adjustable-length loop devices are two common suspensory loop devices that are used in ACL reconstruction. They both have their own biomechanical pros and cons. The purpose of this study is to determine the difference in functional outcome of anatomical single bundle ACL reconstruction using fixed length versus adjustable length loop in femoral fixation of quadrupled hamstring graft. Material and methods: It is a longitudinal prospective study conducted in Bone and Joint Centre, Kokilaben Dhirbhai Ambani Hospital (KDAH), Mumbai from Jan 2014 to June 2016. There were 60 patients enrolled in the study. The first 30 patients were treated with Arthroscopic ACL reconstruction in the first 30 patients were done with quadrupled hamstring graft from ipsilateral limb fixed with Endobutton on femoral side and bio-absorbable intrafix tibial screw, similarly in subsequent 30 patients ACL reconstruction were done with quadrupled hamstring graft from ipsilateral limb fixed with Tightrope on femoral side and bio-absorbable intrafix tibial screw. Their clinical and functional status were assessed pre-operatively on the day prior to surgery and the last follow up at one following the surgery with Tegner-Lysholm Score and 2000 IKDC scores. Results: The average Tegner- Lysolm score before surgery in Endobutton group was 56.63±6.7 and post op score at last follow up was 93.97±4.1 and for Tightrope group it was 56.5±7.1 and 94.7±3.7 respectively. The average 2000 IKDC score before surgery in Endobutton group was 46.16±6.1and post-op score at last follow up was 82.52±4.2 and for Tightrope group it was 46.57±6.5 and 83.98±4.1 respectively. Two sample student t-test was conducted to compare the mean of post-operative Tegner-Lysolm score and 2000 IKDC for each group it showed P value for Tegner-Lysolm score to be 0.75 and that for 2000 IKDC score to be 0.7, which not statistically significant to reject the null hypothesis. Discussion and conclusion: Cortical suspension devices for femoral tunnel graft fixation are very efficient devices whether Fixed-length or adjustable length. Fixed-length and adjustable loop cortical suspension devices are equally effective in femoral fixation of graft in ACL reconstruction.

Clinical and Radiological Outcomes After Hamstring Anterior Cruciate Ligament Reconstructions: Comparison Between Fixed-Loop and Adjustable-Loop Cortical Suspension Devices

Background: Few studies have compared clinical and radiological outcomes after hamstring anterior cruciate ligament (ACL) reconstruction with fixed-loop and adjustable-loop cortical suspension devices. Purpose/Hypothesis: The purpose of this retrospective study was to compare clinical outcomes and tunnel widening after hamstring ACL reconstructions with fixed- and adjustable-loop cortical suspension devices. The hypothesis was that compared with femoral graft fixation with the fixed-loop device, fixation with the adjustable-loop device would show similar clinical outcomes and would result in less tunnel widening after hamstring ACL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 117 consecutive patients underwent hamstring ACL reconstruction at a single institution. The fixed-loop cortical suspension device was used in 67 patients, and the adjustable-loop cortical suspension device was used in 50 patients. All patients were observed for a minimum of 2 years. Postoperative knee laxity was evaluated with the Lachman test, pivot-shift test, and KT-1000 arthrometer. Functional evaluations were performed by use of the Lysholm score and the Tegner activity scale. On anteroposterior (AP) and lateral radiographs, the measured diameters of the femoral tunnel at 1 year after surgery were compared with the diameter of the reamer used at surgery. The measured diameters of the tibial tunnel at 1 year after surgery were compared with those taken immediately after surgery. Results: The mean KT-1000 arthrometer laxity measurement was 1.5 ± 1.8 mm in the fixed-loop group and 1.2 ± 2.3 mm in the adjustable-loop group (P = .530). Results of postoperative knee laxity evaluations and functional outcomes from both groups showed no statistically significant differences. However, the fixed-loop group showed significantly better stability in the pivot-shift test than did the adjustable-loop group (P = .018). On AP radiographs, the mean diameter of the femoral and tibial tunnels increased by 42.2% ± 15.9% and 37.0% ± 17.8%, respectively, in the fixed-loop group and by 43.0% ± 15.4% and 36.8% ± 18.2% in the adjustable-loop group. On lateral radiographs, the mean diameter of the femoral and tibial tunnels increased by 38.1% ± 14.8% and 39.9% ± 13.8%, respectively, in the fixed-loop group and by 35.8% ± 12.2% and 38.1% ± 21.0% in the adjustable-loop group. No significant differences were found between the 2 groups in postoperative femoral and tibial tunnel widening on AP radiographs (P = .801 and .951, respectively) or lateral radiographs (P = .422 and .621, respectively). Conclusion: Compared with femoral fixation by use of the fixed-loop device, femoral fixation by use of the adjustable-loop device showed similar clinical outcomes but did not reduce tunnel widening after hamstring ACL reconstructions.

Comparison of clinical and radiologic outcomes and second-look arthroscopic findings after ACL reconstruction using a fixed-loop and adjustable-loop cortical suspension devices

Comparison of clinical and radiologic outcomes and second-look arthroscopic findings after ACL reconstruction using a fixed-loop and adjustable-loop cortical suspension devices

A Biomechanical Comparison of Femoral Cortical Suspension Devices for Soft Tissue Anterior Cruciate Ligament Reconstruction Under High Loads

Background: Graft healing after soft tissue anterior cruciate ligament (ACL) reconstruction requires rigid fixation to allow for soft tissue healing. Cortical suspension devices for femoral fixation should be biomechanically tested under high loads representative of early rehabilitation to evaluate whether they provide sufficient fixation. Purpose/Hypothesis: To biomechanically compare current fixed-loop and adjustable-loop cortical suspension devices for soft tissue femoral fixation under high loads. The hypotheses were that there would be significant differences in cyclic displacement between devices, independent of loop type, and that retensioning of the adjustable-loop devices would not significantly alter the biomechanical properties of these devices. Study Design: Controlled laboratory study. Methods: Five different femoral ACL graft cortical suspension devices (3 fixed and 2 adjustable) were compared under high cyclic forces (100-400 N for 1000 cycles) and then pulled to failure at 50 mm/min. In addition, the effect of retensioning after simulated preconditioning was evaluated for the 2 adjustable-loop devices. Results: On average, the least amount of cumulative peak cyclic displacement (mean ± SD) was observed for the ENDOBUTTON (1.05 ± 0.05 mm), followed by the RIGIDLOOP (1.09 ± 0.16 mm), XO Button (1.65 ± 0.43 mm), TightRope with retensioning (1.81 ± 0.51 mm), TightRope without retensioning (2.20 ± 0.62 mm), ToggleLoc with retensioning (3.22 ± 1.41 mm), and ToggleLoc without retensioning (3.69 ± 2.39 mm). The ENDOBUTTON displaced significantly less after cyclic loading than all adjustable-loop devices (TightRope and ToggleLoc, both with and without retensioning) and the XO Button. The RIGIDLOOP displaced significantly less than the TightRope without retensioning and ToggleLoc with and without retensioning. There was no significant difference in biomechanical properties after retensioning for both adjustable-loop devices. Conclusion: Significant differences were observed between current fixed-loop and adjustable-loop cortical suspension devices for soft tissue femoral fixation when subjected to high loads experienced during rehabilitation. Retensioning did not significantly alter the biomechanical properties of adjustable-loop devices. Clinical Relevance: Early rehabilitation protocols subject the graft construct to higher forces than what has been previously tested biomechanically. Biomechanical testing of cortical suspension devices under simulated high rehabilitation loads demonstrated significant differences between devices. Future studies should investigate the clinical implications of these time zero results.