Biomechanical comparison of posterior cruciate ligament reconstruction techniques using cyclic loading tests

Abstract

Posterior tibial translation (PTT) of the posterior cruciate ligament (PCL) reconstructed-knee under cyclic loading of 1,000 cycles with a 100-N load was compared between four different procedures, including two reconstructions with patellar tendon graft (transtunnel and inlay techniques) and two reconstructions with hamstring tendon graft (Endobutton and EndoPearl techniques) in twelve fresh-frozen human knees. The EndoPearl technique is a direct tendon fixation using biodegradable interference screws and an anchoring device, while the Endobutton technique is an indirect tendon fixation using a titanium button and surgical tape. The change of PTT after cyclic loading in the Endobutton technique was significantly greater than in the other reconstruction technique. No graft rupture at the killer turn or complete pullout from the bone tunnel was found. The advantage of the inlay technique compared to the transtunnel technique with respect to the posterior stability could not be shown in the current study. Posterior laxity of PCL reconstructed-knees with hamstring tendon graft using the Endobutton technique increased more easily than that with patellar tendon graft. For PCL reconstruction using the hamstring tendon graft, anatomical fixation may be preferable to prevent excessive posterior laxity in the early phase of the rehabilitation protocol.

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

“…The mechanism of the “killer turn” has been illustrated by several biomechanical studies. The excessive load at the acute bend, and repetitive friction because of non‐isometric graft placement are possible explanations of the “killer turn” effect.…”

“…According to the testing protocol of previous experiments, in both groups, after the tibial side of the graft was fixed, the other end of the graft was mounted onto an MTS model‐858 Mini Bionix servohydraulic materials testing machine (MTS Systems, Minneapolis, Minnesota, USA) for the cyclic loading test. Our device employed an MTS Model 858.11 load unit that is fatigue‐rated at 100 N, with a resolution of 0.001 N. This freestanding load unit can be operated at frequencies up to 30 Hz.…”

Biomechanical comparison between single-bundle and double-bundle anterior cruciate ligament reconstruction with hamstring tendon under cyclic loading condition

“…Although the hamstring tendon has several advantages making it superior to a BTB graft, it also has several disadvantages. The tendon fixation to the bone is still a challenge in spite of the numerous surgical devices available [33]. Relatively slow maturation of the tendon-bone interface accentuates the need for retaining the graft firmly when the reconstructed-knee is subject to a repetitive load [34].…”

Isolated Posterior Cruciate Ligament Injuries of the Knee

“…49,50 However, other biomechanical studies have demonstrated only small differences in graft pretension, graft forces, or knee kinematics between tibial inlay and transtibial techniques. [51][52][53][54] Moreover, recent clinical comparisons between tibial inlay and transtibial techniques have failed to demonstrate the superiority of either reconstructive technique for treating isolated PCL insufficiency in short-term to mid-term follow-up. 55,56 Using a quadrupled hamstring autograft, Seon and Song 55 compared transtibial tunnel fixation with a tibial inlay technique using BTB autograft at a minimum 2-year follow-up (level III).…”