Abstract
Background:
Anterior cruciate ligament (ACL) ruptures occur frequently, with ACL reconstruction among the most commonly performed orthopaedic sports surgeries. The remnant ACL is typically debrided for visualization. However, further evidence has suggested that this remnant tissue contains a wealth of proprioceptive nerve fibers and a vascular blood supply. Theoretically, preserving the ACL remnant may improve joint proprioception and graft synovialization. Therefore, ACL hybrid remnant preservation reconstruction (HRPR) was developed to preserve and tension the native remnant in combination with an ACL reconstruction.
Indications:
Patients with proximal tears or femoral-sided avulsions, Sherman type 1 or 2, may be indicated for ACL-HRPR.
Technique Description:
In this technique, we use a bone–patellar tendon–bone (BTB) autograft, which can be harvested based on the surgeon's preference. After performing a diagnostic arthroscopy, the notch of the knee is debrided, with care to preserve the tibial ACL remnant. The tibial remnant is then undermined with electrocautery. Nonabsorbable suture is passed through the remnant tissue. A tibial guide is placed, and a pin is drilled just posterior to the tibial insertion. Next, the appropriately sized tibial tunnel is drilled just posterior to the tibial remnant insertion. Using an anteromedial-portal technique with the knee maximally flexed, an over-the-top guide with appropriate offset is used to insert the guide pin, and the femoral tunnel is drilled. The proximal graft bone block and the remnant sutures are then passed through the femoral tunnel. Metal screws are then inserted to fix the BTB graft bone blocks on the femoral side, followed by the tibial side. Backup fixation is also used by placing a biocomposite anchor 1 cm distal to the tibial tunnel.
Results:
A myriad of techniques exist for preserving the ACL remnant. For the present surgical technique, a retrospective cohort revealed that patients undergoing ACL-HRPR achieved full range of motion without extension loss and equivalent patient-reported outcomes, without increased complication rates.
Discussion/Conclusions:
For patients with femoral-sided ACL tears or avulsion, ACL-HRPR is a viable option that may augment traditional ACL reconstruction.
Patient Consent Disclosure Statement:
The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.
This is a visual representation of the abstract.
Video Transcript
In this video, we present our technique of anterior cruciate ligament (ACL)–hybrid remnant preservation reconstruction (HRPR) with bone-patellar tendon-bone (BTB) autograft. We will discuss relevant background literature, a case presentation followed by our surgical technique, tips and tricks, postoperative rehabilitation, and outcomes.
There are no relevant disclosures to this presentation.
Background and Indications
Over 120,000 ACL injuries occur every year in the United States. 4 Typically, ACL reconstruction (ACLR) has largely served as the gold-standard treatment, with an overall goal of restoring joint stability and preventing cartilage and meniscal damage. 2
Traditionally in ACLR, the tibial remnant is debrided for visualization purposes in the intercondylar notch. However, there has been increasing interest to preserve this remnant tissue. The ACL remnant has been shown to contain an abundance of proprioceptive nerve fibers and vascularity, which may be beneficial to preserve.3,5,7 Incorporation of the remnant has been suggested to improve knee proprioception, graft healing and incorporation, and overall knee stability.1,3,5,7,8 Therefore, we developed a technique that preserves and tensions the native ACL remnant in combination with an ACLR.
This illustration depicts a femoral-sided ACL tear with substantial remnant tissue that is amenable to preservation and repair. Nonabsorbable sutures are passed through the tibial remnant, and these suture limbs are passed through the femoral tunnel. A standard BTB autograft is used for the ACLR, in combination with the remnant ACL preservation. The indication for performing our technique is for proximal femoral-sided ACL tears that are Sherman type 1 or 2.
The following case presentation includes a 21-year-old man who sustained a noncontact hyperextension injury to his right knee while playing soccer. He reports that he heard a pop at the time of injury, which subsequently led to his leg buckling and “giving out.”
On physical examination, his range of motion on presentation was 5° to 90° with lateral joint line tenderness, stable varus, and valgus stress testing, accompanied by an effusion. He had a 2b Lachman and positive anterior drawer. His dial test was negative at both 30° and 90°.
Radiograph imaging of the right knee demonstrated a Segond fracture off of the anterolateral tibia.
Magnetic resonance imaging confirmed the diagnosis of an ACL tear, with accompanying bone bruise off the distal femur. Due to these findings, we elected to perform an ACLR.
Technique Description
In terms of operating room planning for the technique of interest, the patient is laid supine, with a tourniquet applied to the proximal thigh. The operative leg is placed into an arthroscopic leg holder, while the contralateral leg is placed into a padded leg holder. The graft is harvested per the surgeon's preference. The arthroscopic portion of the case is performed with standard anteromedial and anterolateral portals.
This is our movie example of the procedure. This is the lateral wall of the femur and going back to the origin of the ACL. And as you can see, there is a significant ACL remnant. We have hypothesized that saving the remnant will allow for support of a reconstruction and allow for better proprioception from the patient and an ability to return to sport in a more comfortable fashion. This is a technically challenging procedure where again we are trying to save the ACL remnant, and as you can see, we undermine the ACL remnant and drill our ACL tunnel pin right behind the ACL remnant after undermining. We then protect it with a curette and drill with a typical-size ACLR, which is a 10-mm patellar tendon reconstruction in this case. We use a first-pass suture device to pass a fiber-link suture running up and down the remnant when we are doing this type of procedure. Again, we do it typically for at least 3 throws of these passages to allow for good security of the ACL remnant. Now we do this, again, without any cannula in the medial portal at this time, and we do 3 total passages here, and you will see a fiber-link suture being completed when we are done with the passage of the remnant. From there, we do put in a passport cannula to protect the later drilling of the femoral side. Our suture is actually outside of the passport cannula to allow us to put in our beef pin at the origin of the femoral tunnel. We then drill with a low-profile 10-mm reamer into our femur and drill it to a tunnel length appropriate for a bone-tendon-bone reconstruction. We then pass our ACLR graft. Again, we had 2 suture shuttled fiber wires used through the beef pin, one to pass the graft from the tibia up through the femur. And as you can see, the white suture to the right tiger suture will allow us to pass our remnant suture up through the femoral tunnel, as you see here. Once this is passed, we tension both sides and then place a metal screw over the femoral tunnel.
Results and Discussion
We have found the following tips and tricks in performing this technique. It is important to place tunnels in the usual anatomic fashion. First, when preserving the remnant, there is a tendency to place the tunnel too far posteriorly, if the tibial footprint is not elevated. Using electrocautery to elevate this tibial footprint anteriorly allows appropriate guide pin and tibial tunnel placement. Second, it is key to preserve as much of the ACL remnant as possible when debriding the notch to aid in passing sutures through the remnant. Third, after nonabsorbable sutures are passed through the remnant ACL, place a cannula in the anteromedial portal to protect the remnant repair sutures during femoral tunnel drilling. This also allows retraction of the remnant by pulling on these sutures and snapping them to the drapes. Fourth, one should use a similar-sized ACL graft. There is no need to downsize the diameter to accommodate both the remnant and reconstruction. Finally, to pass the graft and the remnant preservation sutures, use 2 looped suture links through the femoral tunnel, with one loop through the tibial tunnel to pass the ACL graft and the other to pass the repair sutures from the anteromedial portal.
Our rehabilitation protocol is featured here. This does not deviate from our standard ACL rehabiliation protocol.
In terms of patient outcomes, Moutzouros et al 6 retrospectively examined 104 patients undergoing the ACL-HRPR technique. Compared to controls, they found that patients undergoing this technique achieved similar Patient Reported Outcomes Information System–Physical Function and Pain Interference scores, achieved full range of motion without loss of extension or increased cyclops lesions, and had no differences in complications such as rerupture.
Here are the references for this presentation. Thank you.
Footnotes
The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
