Passive Knee Stability After Anterior Cruciate Ligament Reconstruction Using the Endobutton or ToggleLoc With ZipLoop as a Femoral Fixation Device: A Comparison of 1654 Patients From the Danish Knee Ligament Reconstruction Registry

Abstract

Background:Biomechanical studies show varying results regarding the elongation of adjustable fixation devices. This has led to growing concern over the stability of the ToggleLoc with ZipLoop used in anterior cruciate ligament (ACL) reconstruction (ACLR) in vivo.Purpose/Hypothesis:The purpose of this study was to compare passive knee stability 1 year after ACLR in patients in whom the Endobutton or ToggleLoc with ZipLoop was used for femoral graft fixation. The hypothesis was that the ToggleLoc with ZipLoop would be inferior in knee stability to the Endobutton 1 year after primary ACLR.Study Design:Cohort study; Level of evidence, 2.Methods:Data from 3175 patients (Endobutton: n = 2807; ToggleLoc with ZipLoop: n = 368) were included from the Danish Knee Ligament Reconstruction Registry (DKRR) between June 2010 and September 2013. Data were retrieved from standardized ACL forms filled out by the operating surgeon preoperatively, during surgery, and at a clinical examination 1 year after surgery. Passive knee stability was evaluated using 1 of 2 arthrometers (Rolimeter or KT-1000 arthrometer) and the pivot-shift test. Using the same database, the number of reoperations performed up to 4 years after primary surgery was examined.Results:Full data were available for 1654 patients (Endobutton: n = 1538; ToggleLoc with ZipLoop: n = 116). ACLR with both devices resulted in increased passive knee stability (P < .001). Patients who received the ToggleLoc with ZipLoop were found to have a better preoperative (P = .005 ) and postoperative (P < .001) pivot-shift test result. No statistically significant difference regarding the number of reoperations (P = .086) or the time to reoperation (P = .295) was found.Conclusion:Patients who underwent fixation with the ToggleLoc with ZipLoop had improved passive knee stability 1 year after surgery, measured by anterior tibial translation and pivot-shift test results, similar to patients who underwent fixation with the Endobutton. No difference was seen in knee stability or reoperation rates between the 2 devices.

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

“…Four studies did not meet eligibility criteria: one could not be retrieved in full text [ 20 ], one was not written in English [ 12 ], one was conducted with several graft types [ 44 ], and presented other clinical outcomes than those included by this review [ 45 ]. Three additional studies were identified from the reference list of included studies [ 4 , 14 , 33 ]. Key characteristics for each of the included studies are presented in Table 1 .…”

“…Three studies [ 4 , 5 , 43 ] included revision surgery in their outcome and two studies [ 28 , 34 ] reported on the number of patients undergoing revision surgery during the study period. Only the study by Asmussen et al [ 4 ] analysed the rate of revision surgery with an OR and found that ALDs had 0.51 (95% CI: 0.24–1.13) lower odds of having a revision surgery compared to FLDs. However, this was not statistically significant [ 4 ].…”

“…Only the study by Asmussen et al [ 4 ] analysed the rate of revision surgery with an OR and found that ALDs had 0.51 (95% CI: 0.24–1.13) lower odds of having a revision surgery compared to FLDs. However, this was not statistically significant [ 4 ]. Boyle et al [ 5 ] and Ranjan et al [ 34 ] did not present an OR for the risk of having a revision surgery in the ALD group compared to the FLD group.…”

“…The SSD are reported at the 6 months follow-up in three studies [ 5 , 34 , 43 ], at the 1-year follow-up in three studies [ 4 , 25 , 43 ], and at the 2-years follow-up in five studies [ 5 , 9 , 11 , 14 , 34 ]. There was no difference in the mean SSD between the ALDs and FLDs in either of the studies Table 3 .…”

“…Two studies were judged as having a serious risk of bias due to confounders. One used several tibial fixation methods [ 4 ] and the other used two different surgical techniques [ 43 ]. Most of the studies had a low or moderate risk of bias regarding selection of participants, deviations from intervention, measurement of outcomes, and selection in reported results.…”