This is a review from Techniques in Orthopaedics, detailing the history of ACL reconstructive fixation techniques, compiled to the best of my ability, for those interested.
As early as 270 B.C., Hippocrates described abnormal knee alignment relationships due to cruciate ligament injuries, and the first scholar to describe the ACL in detail was the Roman “royal physician” Claudius Galen (Greece, 129 A.D.), who described the stable structure of the knee by referring to the In 1845, the Lyon scholar Amadee Bonet listed the symptoms associated with ACL injury – a severe, transient injury that can cause blood to accumulate in the joint cavity and loss of knee function. loss of knee function.
The first ACL repair was performed in 1895 by Mayo from Leeds, England, who repaired the ruptured ACL at the femoral attachment and improved the patient’s postoperative limp to the point where he could run six years later.
From the beginning – the era of suture fixation
In 1914, Hesse described a successful procedure performed by Grekow in St. Petersburg, Russia, to take the broad fascia and reconstruct the cruciate ligament. The reconstruction was sutured through the femoral tunnel to the periosteum of the femur and tibia, marking the beginning of ACL graft fixation.
Hey Groves of Bristol, England, reported in 1917 on his procedure to reconstruct the ACL using the iliotibial bundle, which was taken partially through the femoral and tibial tunnels and sutured to the periosteum and fascia at the exit of the tibial tunnel (Figure 1).
Figure 1 Schematic diagram of the ACL reconstruction done by Hey Groves in 1917 using the suture fixation technique
In the 1930s, pioneers such as Campbell and Macey also tried to reconstruct the ACL using patellar ligament and semitendinosus grafts, but the fixation of the grafts was still mainly sutured to the periosteum.
The first time the surgical pioneers such as Campbell, Macey and others also tried to apply grafts such as patellar ligament and semitendinosus to reconstruct ACL, but the fixation of grafts was still mainly sutured to the periosteum.
In 1956, Augustine introduced the ACL graft fixation technique first proposed by Lindemann. Similar to Macey, this technique also used the semitendinosus tendon for reconstruction, but graft fixation was accomplished by tying the graft to a boat-shaped nail. This attempt ushered in a new era in the way ACL reconstruction grafts were fixed.
Bru¨ckner’s attempt in 1966 to press-fix a cortical patellar ligament taken from the tibial tuberosity into the tibial tunnel is considered the beginning of the press-fit technique for ACL reconstruction (Fig. 2), and he also experimented with the use of cortical bone Button fixation for the purpose of tensioning the graft.
Figure 2 Press-fit technique as described by Bru¨ckner
In 1969, Franke introduced the concept of bone tunnel interface fixation, i.e., the use of a wedge-shaped bone block to fix the bone-tendon-bone graft to the tibia and femur, respectively, and reported 100 cases of ACL reconstruction at the 1976 Ski Trauma Symposium.
The success of this technique meant that the use of the graft’s own frictional force provided sufficient stability to prevent displacement without the use of additional fixation (Figure 3).
Figure 3 Kenneth Jones describes a modified procedure utilizing the middle 1/3 of the patellar ligament for reconstruction
In the 1970s, techniques for extra-articular non-anatomic reconstruction using the broad fascia became popular, represented by Galway, Macintosch, Lemaire, and others, and in 1979, Marshall introduced a method of reconstruction using the patellar ligament in which the graft is secured around the femoral epicondyle to Gerdy’s tuberosity.
A full ACL graft reconstruction appeared in 1987, reported by Hertel, and the initial technique was a minimally invasive procedure assisted by arthroscopy. Hertel and Behrend later described a method of fixing the graft on the tibial side using a bone pin.
Based on the above work, several authors have improved.
(1) Boszotta performed a total arthroscopic procedure
(2) Felmet achieved lateral femoral interface fixation by means of a bone peg taken from the femur
(3) Gobbi et al. described the use of tapered tunnels on the femoral side, where the bone graft passes through the femoral tunnel from the outside to the inside for a more secure fixation
Paessler first performed ACL reconstruction using an autologous tendon, the semitendinosus and thin femoral tendons were folded and treated as grafts; the femoral tunnel was drilled from the inside of the joint to the outside, depending on the size of the graft, and the lateral cortex was slightly expanded (from outside to inside) for better fixation, while fixation on the tibial side was accomplished by tying the tunnel opening to the bone.
In order to better understand and appreciate this surgical technique, many authors have performed biomechanical studies and long-term follow-up, which have shown that this surgical technique can achieve biomechanical equivalence to the conventional approach, with essentially the same long-term results.
Transition – evolution of various fixation techniques (1980s)
In 1983, Lambert began fixing bone-tendon-bone grafts with 6.5-mm diameter AO cortical screws, and in 1987, Kurosaka initiated the development of interfacial fixation of ACL grafts by suggesting that fixation of the graft was the key to ACL reconstruction and demonstrating that the interfacial screw fixation technique provided better clinical results than cortical screw fixation.
In the interface screw fixation technique, the screw is inserted in a tunnel parallel to the graft, which presses the graft against the bone wall and produces a biological effect that can provide better stability for early functional exercise.
Several biomechanical studies and long-term follow-ups have confirmed that metal interface screws can be the “gold standard” for bone-tendon-bone graft fixation, and in the following years, various materials such as resorbable materials, polylactic acid, and polyglycolic acid have been tried.
Lipscomb et al. used semitendinosus and thin femoral tendons for ACL reconstruction with tibial fixation, and Friedman subsequently introduced the free N-cord tendon as a graft. in the 1990s, the replacement of bone-tendon-bone with free tendon became the trend, and this shift was facilitated by the development of soft-tissue fixation techniques, such as the round-headed soft-tissue fixation interface screw and the Endobutton.
Building on previous efforts, Pinczewski used blunt-threaded metal interface nails to fix grafts in 1993, a technique that was later extended to non-metallic bioresorbable interface screws.
The Endobutton, pioneered by Rosenberg, is the most widely used technique for lateral femoral ACL graft fixation, originally designed for tendon graft fixation by a polyester ring, which was gradually replaced by a self-contained ring structure for the fixator.
In 1994, Paessler utilized a transverse kerf pin for fixation on the tibial side of the graft (Figure 4), which is considered to be the beginning of the transverse nail or suspension fixation technique.
Figure 4 Bone – tendon – bone graft + tibial transverse pin system
Clark developed the transverse nailing technique in 1998 and influenced the next 10 years, with the initial metal transverse nails being replaced by bioresorbable materials. 2002 saw the introduction of the RigidFix transverse nailing system, initially for lateral femoral and gradually extended to lateral tibial fixation.
Because there is no bone block at either end, fixation of tendon grafts is recognized as the weak link, and tendon-bone healing takes significantly longer than bone-bone healing. Currently, there is still no definitive opinion on the best way to fixate tendon grafts.
For tendon graft tunnel external fixation, the primary concern is the loss of strength and relaxation, which is considered to be related to the “bungee effect” and “wiper effect”, which can lead to expansion of the bone tunnel and affect graft healing.
The advantage of the tunnel fixation system, represented by the interface screw, is that it reduces the working length of the graft and increases its strength; there is evidence that this fixation system also significantly improves the healing of the graft and tunnel; Weiler et al. showed in animal studies that the interface nail system is effective in improving early graft-bone tunnel healing.
However, in biomechanical studies, it has been found that the interface nail system is greatly influenced by the screw length, diameter, and threads, and that the failure load may be around 450 N, which is within the required safe load range; in contrast, the maximum load that can be increased by the tunnel external fixation system can be 750-1100 N.
A recent META analysis showed that the Endobutton-tendon graft combination was the most stable for ACL reconstruction; in another systematic review, Lee and his team concluded that in-tunnel and out-of-tunnel fixation systems were similar, but that patients who received in-tunnel fixation returned to weight bearing and jogging sooner.