A prospective evaluation of tunnel enlargement in anterior cruciate ligament reconstruction with hamstrings: extracortical versus anatomical fixation

Abstract

Changes in the femoral and tibial bone tunnel were studied prospectively after arthroscopic ACL reconstruction with quadruple hamstring autograft. To determine whether tunnel enlargement can be decreased by fixing the graft close to the joint line having a stiffer fixation construct we compared "anatomical" (one absorbable interference screw femorally, and bicortical fixation with two absorbable interference screws tibially) and extracortical fixation techniques (Endobutton femorally, and two no. 6 Ethibond sutures over a suture washer tibially). Over a 2-year period we evaluated 60 patients clinically (IKDC scale, Cincinnati Knee Score, KT-1000) and radiographically (confirmed by MRI). The operated knee was radiographed immediately postoperatively and 6 and 24 months postoperatively. The femoral and tibial bone tunnel diameter was measured on anteroposterior and lateral images, and the tunnel area was calculated and compared to the initial area calculated from the perioperative drill size. In the "anatomical" group the immediately postoperative bone tunnel area was 75% larger than the initial tunnel area, after 6 months it was increased another 31%, and between 6 and 24 months it remained basically unchanged. In the "extracortical" group there was no significant enlargement immediately postoperatively, but after 6 months it was 65% larger than the initial area of drill and graft size, and between 6 and 24 months it decreased to 47%. There was no correlation between the amount of tunnel enlargement and clinical scores or KT-1000 measurement. Arthroscopic ACL reconstruction with quadruple hamstring autograft is associated with bone tunnel enlargement. Using a purely extracortical fixation technique thus significantly increased the tibial and femoral tunnel area during the first 6 postoperative months, while it decreased slightly thereafter. The insertion of large interference screws apparently not only compresses the graft in the bone tunnel but also significantly enlarges the bone tunnel itself. The immediate enlargement at the time of the operation is followed by a reduced further enlargement at 6 months and then stabilization. Tunnel widening did not influence clinical outcome over a 2-year period.

Comparison of tunnel widening between interference screw and suture disc fixation after ACL reconstruction using CT scan

“…15 Buelow, Fauno, Iorio have all concluded that there was a significant reduction of tunnel widening using fixation points close to the joint compared to the system where the distance between fixation points is long. 11,14,28 In our study also, there was significantly less tunnel enlargement (p-value) with the use of interference screw as compared to suture disc. We have observed tunnel enlargement in the early postoperative period (2 weeks) probably because we have used extraction drilling.…”

“…[6][7][8][9] Tunnel enlargement is known to occur in first 6 months after ACL reconstruction and declines thereafter. 10,11 It is not seen 2 years after ACL reconstruction. No study has yet identified any effect on clinical stability or arthrometer measurements due to tunnel enlargement.…”

“…No study has yet identified any effect on clinical stability or arthrometer measurements due to tunnel enlargement. [11][12][13][14] Nevertheless, long-term implications and difficulty in revision surgery are matters of concern.…”

Comparative study between aperture and suspensary fixation of hamstring autografts on femoral side in ACL reconstruction: clinical and radiological outcome assessment

“…Buelow et al performed a prospective nonrandomized trial comparing femoral fixation with a bioabsorbable interference screw with an EndoButton. 14 The results demonstrated ACL reconstruction with a doubled semitendinosus and gracilis tendon graft and associated femoral and tibial tunnel enlargement. The authors found considerably more tunnel widening in the grafts fixed with extracortical fixation.…”

Isocinetisme et sport de haut niveau : Applications à la traumatologie du sport

“…Sur les DIDT, aucune fixation osseuse ne fait l'unanimité. Dès les premiers jours, et ce quel que soit le mode de fixation utilisé, une ostéolyse des tunnels fémoraux et tibiaux s'opère (Buelow, Siebold, & Ellermann, 2002). Il y aurait unélargissement des tunnels qui se stabiliseraità six mois, ce qui nous inciteà rester prudents dans la sollicitation de la plastie.…”