DOS 2016

DOS Kongressen 2016 ·

Passive knee stability after anterior cruciate ligament

reconstruction using Endobutton or ToggleLoc with

ZipLoop as femoral fixation device – a comparison of

3175 patients from the Danish Knee Ligament Reconstruction

Register

Christian Asmus Peter Asmussen, Mikkel Lindegaard Attrup, Kristian Thorborg,

Per Hölmich

Sports Orthopedic Research Center Copenhagen (SORC-C), Arthroscopic

Center, Department of Orthopedic Surgery, Copenhagen University Hospital,

Amager-Hvidovre Denmark

Background:

Clinical and biomechanical studies show different results regard-

ing the stability and possible elongation of adjustable fixation devices. This has

lead to growing concern over the stability of ToggleLoc with ZipLoop used in

ACLR in vivo.

Purpose / Aim of Study:

This study aims to compare passive anterior knee

stability 1 year after anterior cruciate ligament reconstruction (ACLR) in pa-

tients where Endobutton or ToggleLoc with ZipLoop was used for graft fixation.

Materials and Methods:

Data from 3175 patients was included from the

Danish Knee Ligament Reconstruction Register between June 2010 and

September 2013. 2807 patients were operated with Endobutton and 368

were operated with ToggleLoc with ZipLoop. Data was retrieved from standard-

ized anterior cruciate ligament forms. Knee stability was evaluated using one of

two arthrometers – Rolimeter or KT1000 – and the pivot shift test.

Findings / Results:

ACLR with both fixation devices resulted in increased

knee stability (p < 0.001). A significant difference in mean postoperative an-

terior tibial translation between Endobutton (-1.25 mm, std. dev. 1.9 mm) and

ToggleLoc with ZipLoop operated patients (-0.83 mm, std. dev. 1.7 mm) was

found (p < 0.001). ToggleLoc with ZipLoop operated patients were found to

have a better preoperative (p < 0.001) and postoperative (p < 0.001) pivot

shift test score. Despite this, the level of improvement in pivot shift test scores

for both devices was similar (p = 0.188).

Conclusions:

Patients operated with ToggleLoc with ZipLoop have significantly

larger passive knee stability with less anterior tibial translation and better pivot

shift test scores 1 year after surgery. The use of either device is not expected

to produce any differences of clinical importance and, therefore, will not affect

the favorability of one device over the other.

No conflicts of interest reported

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