2015 ISAKOS Biennial Congress ePoster #1236

Risk of Revision and Fixation Methods. A Study Based on 38 666 Primary ACL Reconstructions With Hamstring Autografts

Tone Gifstad, MD, PhD, Trondheim NORWAY
Andreas Persson, MD, Oslo NORWAY
Asle Kjellsen, MD, Bergen NORWAY
Lars Engebretsen, MD, PhD, Oslo/Lausanne NORWAY
Martin Lind, MD, PhD, Prof., Aarhus N DENMARK
Magnus Forssblad, MD, PhD, Stockholm SWEDEN
Grethe Albrektsen, PhD, Trondheim NORWAY
Jon O. Drogset, Prof., Trondheim NORWAY
Jonas Fevang, MD, PhD, Bergen NORWAY

Orthopaedic Research Center, Trondheim, NORWAY

FDA Status Not Applicable

Summary: Both femoral and tibial fixation methods of hamstring autografts seem to be of significance when evaluating risk of revision after primary ACL reconstruction with hamstring autografts.

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Abstract:

Introduction

The hamstring autograft is one of the most common grafts used for ACL reconstruction and a large number of fixation methods are available. Clinical long-term follow-up studies contain limited information on risk of revision. Revision ACL reconstruction is a relatively rare event and large registry-based prospective studies make it possible analyze differences in risk of revision according to clinical and demographic factors. The aim of the present registry-based study was to compare risk of revision between various femoral and tibial fixation methods.

Methods

A total of 38 666 patients undergoing primary ACL reconstructions in the period 2004-2011 were included in the present study. The median follow-up time was 3 years (range 0 to 8 years). Fixation devices used in a limited number of patients were grouped according to the point of the fixation. To compare the risk of revision between various fixation methods, the multiple Cox proportional hazard (PH) regression model was applied. Hazard rate ratios (HR with 95% confidence interval (CI)) were reported as measure of effect.

Results

The most common fixation methods in the present data were Endobutton (36%) and Rigidfix (31%) in the femur and interference screw (48%) and Intrafix (34%) in the tibia. The present data included a total of 1042 revision ACL reconstructions. Very few of the revisions occurred during the first year of follow-up. Based on a Cox PH regression model stratified for country and mutual adjustment for gender, age at surgery (five-year categories), activity at the time when the primary injury occurred, femoral fixation and tibial fixation, we found significantly lower risk of revision for the transfemoral fixation devices Rigidfix (0.69 (0.57-0.83)) and Transfix (0.74 (0.58-0.93)) compared with the cortical device Endobutton (ref.). The same model showed that a retro interference screw used for tibial fixation had a higher risk of revision (1.91 (1.27-2.87)) compared with a standard interference screw (ref.).

Discussion

and conclusions: In view of the findings in the present study, both femoral and tibial fixation methods of hamstring autografts seem to be of significance when evaluating risk of revision after primary ACL reconstruction with hamstring autografts.