Tunnel enlargement 5 years after anterior cruciate ligament reconstruction: a radiographic and functional evaluation

Abstract

We, like some authors, have shown that the use of interference screws in tibial fixation despite being aperture fixation actually has a greater amount of tibial enlargement. This lends weight to the biological theory to tunnel enlargement.

Press-fit fixation using autologous bone in the tibial canal causes less enlargement of bone tunnel diameter in ACL reconstruction - a CT scan analysis three months postoperatively

“…al. showed a greater amount of tunnel expansion for the absorbable screws than for extracortical fixation techniques [ 5 , 6 ]. As shown in our study, a tibial press-fit fixation close to the joint line with autologues bone blocks in combination to an extracortical fixation may be an alternative to screw fixation close to the joint line.…”

“…It has been proposed that graft fixation more closely to the joint line may reduce bone tunnel widening [ 4 ]. Adversely, a larger extent of bone tunnel diameter was shown, when using bioabsorbable screws compared to an extracortical fixation at the tibial side [ 5 , 6 ].…”

Prospective Comparisons of Femoral Tunnel Enlargement With 3 Different Postoperative Immobilization Periods After Double-Bundle Anterior Cruciate Ligament Reconstruction With Hamstring Grafts

“…Several biological theories have been proposed: synovial fluid propagation within bony tunnels, localized bone necrosis possibly caused by the drilling process due to thermogenic effects that induce a nonspecific inflammatory response, biochemical mediators, and so on. [12][13][14]24 Zysk et al 25 studied synovial fluid samples collected from patients after ACL reconstruction and reported that patients with bone tunnel enlargement had higher concentrations of tumor necrosis factor a, interleukin 6, and nitric oxide, indicating the involvement of these mediators in tunnel enlargement. Kawaguchi et al 20 reported that there was significantly less femoral tunnel enlargement after anatomic double-bundle ACL reconstruction with hamstring grafts than after single-bundle reconstruction; the potential mechanisms were less tension on the tunnel edge due to force sharing by the 2 bundles, less synovial fluid propagation because of a smaller tunnel diameter, and earlier graft remodeling and revascularization because of smaller grafts.…”

What Role Does Low Bone Mineral Density Play in the “Killer Turn” Effect after Transtibial Posterior Cruciate Ligament Reconstruction?

“…It has been well acknowledged that tunnel inlet enlargement is a frequent phenomenon after ACL reconstruction. According to the published literature, the amount of tibial tunnel volume enlargement ranged from 18.2 to 73.9%. Two broad categories of risk factors have been proposed: mechanical and biological factors.…”

“…The transtibial technique is a popular technique of PCL reconstruction. Although the transtibial technique has the advantages of patient positioning and lower technical difficulty, the “killer turn” has frequently been documented as a primary drawback of this technique. Given the anatomy of the tibial posterior cortex and the direction of tibial and femoral tunnels, there is a sharp angle of the graft at the inlet of the proximal tibial tunnel, which is referred as the “killer turn” after transtibial PCL reconstruction.…”