Bone tunnel enlargement after anterior cruciate ligament reconstruction with the hamstring autograft and endobutton fixation technique

Abstract

The aim of this study was to describe the contrast-enhanced magnetic resonance imaging (MRI) appearance of bone tunnel enlargement detected on radiography after anterior cruciate ligament (ACL) reconstruction with semitendinosus and gracilis tendon endobutton (STG-endobutton) fixation technique. Fourteen patients with a STG-endobutton ACL reconstruction were examined 3 months (n = 1), 1 year (n = 1) and 2 years (n = 12) postoperatively. An age- and sex-matched group with a bone-patellar tendon-bone (BTB) autograft ACL reconstruction with similar follow-up was taken as control. Data on clinical examination, laxity and isokinetic muscle torque measurements, anteroposterior and lateral view radiography were obtained, and knee scores (Lysholm and Tegner) were collected. Contrast-enhanced MRI was performed in the STG-endobutton group with a 1.5-T imager. There were no statistical differences between the groups with respect to clinical findings, stability tests, or knee scores. In the STG-endobutton group the average femoral and tibial bone tunnel diameter detected on anteroposterior view radiography had increased at 2-year follow-up by 33% and 23%, respectively. On MRI the ligamentous graft itself was not enhanced by the contrast medium whereas periligamentous tissue within and around the STG graft bundles showed mild contrast enhancement. In conclusion, the MRI results suggest that enhancing periligamentous tissue accumulated in and around the STG graft associated with the tunnel expansion. In spite of the significant bone tunnel enlargement observed on the follow-up radiography the STG-endobutton knees were stable and the patients satisfied.

A comparison of quadruple semitendinosus and patellar tendon grafts in reconstruction of the anterior cruciate ligament

“…We also advocated immediate weight-bearing with a range of movement of 0° to 130°. Our clinical findings support the observation that there is no difference in strain or stress between patellar tendon and four-stranded hamstring grafts in response to cyclic submaximal loading, 26 The importance of minimising the distance between the fixation points to reduce creep when using different grafts has been widely discussed, 24,[27][28][29][30] but no clinical comparisons have been reported between different hamstring fixation techniques. Therefore, it is still not clear if the hamstring graft would provide less laxity if the fixation distance was minimised.…”

Evaluation of tibial bone-tunnel changes with X-ray and computed tomography after ACL reconstruction using a bone-patella tendon-bone autograft

“…The longer lever arm on the tibial side causes more mechanical stress Fig. 4 a, clinical results [1][2][3][4]14]. We have one explanation for this result: the bone-tunnel changes are not only circular.…”

“…In recent years there have been some reports of bone-tunnel enlargement after ACL reconstruction using autografts [4,5]. Most reports have identified that the bonetunnel enlargement as evaluated with X-rays did not correlate with knee instability [1][2][3][4]14]. On the other hand, a few reports have shown that bone-tunnel enlargement was related to clinical results [7].…”

Does bone impaction technique reduce tunnel enlargement in ACL reconstruction?

“…CT scanning has been recommended for evaluating the dimensions of the bone tunnels. Compared to plain X-ray films, MSCT has the advantage that it does not depend on geometric factors that may influence measurement, such as a small change in knee positioning or in the exposing distance from the film surface [10,12,13]. We decided to use MSCT images because this technique depicts the real boundaries of the trans-osseous tunnel more exactly.…”