Adjustable loop ACL suspension devices demonstrate less reliability in terms of reproducibility and irreversible displacement.

Ahmad, Sufian; Hirschmann, Michael T; Voumard, Benjamin; Kohl, Sandro; Zysset, Philippe; Mukabeta, Takura; Evangelopoulos, Dimitrios Stergios; Ateschrang, Atesch (2018). Adjustable loop ACL suspension devices demonstrate less reliability in terms of reproducibility and irreversible displacement. Knee surgery, sports traumatology, arthroscopy, 26(5), pp. 1392-1398. Springer 10.1007/s00167-017-4769-2

ahmad1.pdf - Published Version
Available under License Publisher holds Copyright.

Download (1MB) | Preview


The aim of this study was to perform a comprehensive biomechanical examination of frequently applied femoral cortical suspension devices, comparing the properties of both fixed and adjustable fixation mechanisms. It was hypothesized that adjustable loop devices demonstrate less consistent fixation properties with increased variability compared to fixed loop devices.


Nine frequently applied fixation button types were tested, six adjustable and three rigid loop devices. Six samples of each device type were purchased. Each device was installed in a servo-hydraulic mechanical testing machine, running a 2000 cycle loading protocol at force increments between 50 and 500 N. Irreversible displacement in mm was measured for all of the tested samples of each implant. Ultimately, maximum load to failure was applied and measured in Nm. An irreversible displacement of 3 mm was considered failure of the implant.


Three of the six adjustable devices (GraftMax™, TightRope® ToggleLoc™) demonstrated a median displacement above the threshold of clinical failure before completion of the cycles. All adjustable loop devices showed a wide intragroup variation in terms of irreversible displacement, compared to fixed-loop devices. Fixed-loop devices provided consistent reproducible results with narrow ranges and significantly lower irreversible displacement (p < 0.05), the maximum being 1.4 mm. All devices withstood an ultimate force of more than 500 N.


Adjustable loop devices still show biomechanical inferiority and demonstrate heterogeneity of fixation properties with wide- and less-reproducible displacement ranges resultant to the mechanism of adjustment, denoting less reliability. However, three adjustable devices (RIGIDLOOP™ Adjustable, Ultrabutton ◊, ProCinch™) demonstrate fixation capacities within the margins of clinical acceptance. RIGIDLOOP™ Adjustable provides the most comparable fixation properties to fixed loop devices.

Item Type:

Journal Article (Original Article)


04 Faculty of Medicine > Pre-clinic Human Medicine > Institute for Surgical Technology & Biomechanics ISTB [discontinued]
04 Faculty of Medicine > Department of Orthopaedic, Plastic and Hand Surgery (DOPH) > Clinic of Orthopaedic Surgery

UniBE Contributor:

Ahmad, Sufian, Voumard, Benjamin, Kohl, Sandro, Zysset, Philippe, Evangelopoulos, Dimitrios Stergios


500 Science > 570 Life sciences; biology
600 Technology > 610 Medicine & health








Lilianna Bolliger

Date Deposited:

25 Jan 2018 10:53

Last Modified:

05 Dec 2022 15:09

Publisher DOI:


PubMed ID:


Uncontrolled Keywords:

ACL TightRope® ACL reconstruction ACL repair Adjustable button ENDOBUTTON◊ CL ULTRA Femoral cortical suspension device Fixed button GraftMax™ Irreversible displacement ProCinch™ RIGIDLOOP RIGIDLOOP™ Adjustable RetroButton ToggleLoc™ Ultrabutton◊




Actions (login required)

Edit item Edit item
Provide Feedback