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

Abstract

Thirteen patients who underwent anterior cruciate ligament (ACL) reconstruction with bone-patella tendon-bone autografts (BTB) using interference screws were the subjects of this study. We analysed the relationship between bone-tunnel changes and clinical results 2 years after ACL reconstruction. To investigate changes, X-ray images were used to evaluate bone-tunnel enlargement, and computed tomography (CT) was used to evaluate the sclerotic area around the bone tunnel. The KT-2000 was used to measure the discrepancy of tibial anterior displacement between the affected and nonaffected sides (DTAD). There was no correlation between bonetunnel enlargement and DTAD. On the other hand, in the CT evaluation, there was a significant correlation between the sclerotic area and DTAD. Our results suggest that it is more significant to analyse the area of sclerotic change than bone-tunnel enlargement for clinical evaluation. We cannot evaluate bone-tunnel changes correctly with two-dimensional X-rays and cannot analyse the sclerotic area using X-rays. Therefore, we recommend that CT, with which it is possible to analyse the sclerotic area, be used to evaluate bone-tunnel changes and clinical results.Résumé 13 patients ayant bénéficié d'une reconstruction du ligament croisé antérieur avec une auto-greffe à partir de la rotule et du tendon rotulien par des vis d'interférence ont été le support de cette étude. Nous avons utilisé la relation entre les modifications des tunnels osseux et les résultats cliniques deux ans après la reconstruction du ligament croisé antérieur. Afin d'analyser les modifications au niveau du tunnel osseux, les images radios montrant un élargissement au niveau du tunnel osseux ont été utilisées de même que le scanner afin d'évaluer également la sclérose osseuse autour du tunnel. Les résultats cliniques ont été analysés à l'aide du KT 2000 mesurant le tiroir intérieur entre les deux genoux (genou normal, genou opéré). Il n'y a aucune corrélation entre l'élargissement du tunnel osseux et des modifications du tiroir intérieur, d'autre part, lors de l'évaluation par scanner, il existait une relation significative entre l'aspect sclérotique du tunnel et les modifications de tiroir. Notre étude nous permet de suggérer, qu'il est plus utile d'analyser la sclérose du tunnel plutôt que son élargisse-ment. Il n'est pas possible d'évaluer les modifications du tunnel osseux avec une radio face/profil de même en ce qui concerne l'os scléreux. C'est pour cette raison que nous recommandons l'utilisation du scanner qui permet cette analyse de façon précise et qui permet par ailleurs de faire la relation entre ces modifications et les résultats cliniques.

Does bone impaction technique reduce tunnel enlargement in ACL reconstruction?

“…They concluded that using an anatomical fixation with stiff and strong fixation devices combined with a less aggressive rehabilitation program could contribute to minimizing tunnel enlargement after ACL reconstruction with doubled hamstrings. Other reported series with different time periods showed the increase in the width of the tunnels from 6 weeks up to 2 years [5,12,20,21]. In the current study, measurements of tunnel diameters taken in a follow-up period after 2 years were found in similar ranges to reported series in the literature (Table 1).…”

“…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.…”

How to evaluate bone tunnel widening after ACL reconstruction - a critical review

“…The tunnel walls were either evaluated in reformatted planes or on 3D volume rendering images. Fink et al showed that computed tomography is superior to plain radiographs for evaluating bone tunnel enlargement on the tibial side, especially in the early postoperative phase, when the tunnel margins are sometimes hard to identify on radiographs 7,16 . In addition, measurement of the tunnel width on CT images is less dependent on the patient position in the scanner and therefore significantly reduces the degree of measurement error 7 .…”

“…Generally, the routine radiological assessment, whether for study purposes or clinical routine, consists of weight-bearing antero-posterior, lateral and tunnel view radiographs. However, it is often difficult to reliably identify the femoral tunnel aperture on radiographs and measure the width of the tunnel 16,45 . Hence, the interpretation of absolute bone tunnel size measurements using radiographs can be misleading.…”

Bone tunnel widening following arthroscopic reconstruction of anterior cruciate ligament (Acl) using hamstring tendon autograft and its functional consequences

“…Some authors report a decrease in tunnel diameter three years after surgery [3] . Although many studies showed no effects of bone tunnel widening on clinical outcomes or objective laxity [3,5,8,9,11,12,13,14] , a few investigations demonstrated that it might be associated with anterior knee laxity and an early sign of graft failure [15,16] . Thus, the clinical significance of bone tunnel widening has not yet been fully established and is still unclear.…”