Abstract
Background:
Revision posterior cruciate ligament reconstruction (PCLR) is challenging, especially in existing semi-anatomic tunnels, whereas there is an increased risk of overlapping with a new positioned anatomic tunnel. Few cases were published with no consensus regarding the optimal operative technique.
Indications:
A 22-year-old male patient, with failed PCLR with hamstring autograft in 2020 due to improper tunnels placement, presented for pain and instability of his right knee. Physical examination revealed a positive posterior drawer and reverse Pivot-Shift test, with no varus-valgus or rotational laxity. Radiograph showed no signs of arthritis, normal tibial slope, and normal long-leg standing axis. Magnetic resonance imaging showed rupture of the PCL graft with no meniscal, chondral, or concomitant ligament injuries.
Technique Description:
We described a single-bundle transtibial technique with a posterior transeptal portal approach to reconstruct the PCL. We started by preparing the allograft with an internal brace augmentation and an adjustable button (Arthrex) placed on the femoral side for cortical fixation. The old semi-anatomical femoral tunnel was drilled and grafted using an allograft bone dowel (Biobank), and a new anatomic femoral tunnel was drilled inside-out. Under direct visualization via posterior transeptal portals, a new anatomic tibial tunnel was drilled posterior to the existing nonanatomic tunnel. Using a shuttle suture, the transplant was passed and fixed by an adjustable button at the femur and by two interference screws and a backup fixation using a Swive-lock anchor at the tibia (Arthrex).
Results:
Favorable functional and clinical outcomes with improvement of anteroposterior stability. Significant improved side-to-side differences on posterior stress radiography and improved subjective and objective clinical scores. Satisfactory outcomes with 75% of patients returned to preinjury Tegner activity scale level of function.
Discussion/Conclusion:
The use of the posterior transeptal portals approach protects the vital neurovascular structures and ensures proper PCL tibial tunnel placement by providing direct visualization of the tibial attachment. Allograft bone dowels facilitate PCL revision in a one-stage procedure by filling the existing semi-anatomic tunnels and allowing to drill the new anatomic tunnels without tunnel overlap. The use of the internal brace augmentation strengthens the construct to protect the graft during the revascularization and remodeling process by facilitating tissue ingrowth and incorporation. In revision surgery, backup fixation is encouraged and often essential due to the compromised bone stock.
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.
Keywords
Video Transcript
This is a video describing the technique for revision posterior cruciate ligament reconstruction (PCLR).
Failure rate of a PCLR is around 11% in literature. 6
It is often due to improper tunnel placement, lower-extremity malalignment, or unrecognized associated ligamentous injuries. 1
It is a challenging procedure with no consensus regarding the optimal operative technique.3,8-10
It can be done as the following:
One- or two-stage surgery, depending on the size and position of the existing tunnels
Transtibial or inlay technique
Single- or double-bundle reconstruction, and/or
With a different graft fixation method
Our case study featured a 22-year-old male patient who was athletic with a Tegner preinjury level 9 and participating in pivoting sports.
In his history, he underwent a PCLR surgery in his right knee 2 years ago using the hamstring autograft.
His main complaint was a feeling of giving out during weightbearing and pain.
Physical examination revealed a positive posterior drawer test and a positive reverse Pivot-Shift test, with no varus-valgus or rotational laxity.
Images from magnetic resonance imaging showed a new rupture of the PCL graft due to a misplacement of both tibial and femoral tunnels.
On this coronal image, we can see a semi-anatomic entry point of the existing femoral tunnel.
Anatomically, it is much closer to the roof of the notch and tangent to the articular cartilage as seen in this image.
Concerning the tibial tunnel, we can see in these images a completely nonanatomic one.
Anatomically, it is more lateral on frontal and axial cuts and more distal on the sagittal cut like represented here on these images.
On preoperative planning,
We decided to use the transtibial single-bundle technique
Our graft of choice was an allograft with an internal brace augmentation
Since the existing femoral tunnel is semi-anatomic, we decided to improve it in a one-stage procedure by grafting the old one using an allograft bone plug to avoid overlap and create a new anatomic tunnel
Because the existing tibial tunnel is completely not anatomic, we decided to create a new anatomic tunnel, more lateral and distal, knowing that the existing tunnel will not interfere with the new one
We did a posterior transeptal approach for direct visualization of tibial tunnel placement
Finally, fixation was achieved by an adjustable button on the femoral side and two interference screws with backup fixation on the tibial side
Let’s start by the technique:
The patient is placed supine with a tourniquet cuff at the base of the thigh.
The first step consists of preparing the allograft folded in two and attaching it to the adjustable button at its femoral side. The graft is then measured.
We added a fiber tape for internal brace augmentation through the free ends of the adjustable button, secured to the graft by sutures.
We started by re-using the existing medial incision.
The next step is to identify the old semi-anatomic femoral tunnel. A guide pin is inserted to view its trajectory.
Next, incisions for optic anterolateral and instrumental anteromedial portals are done.
The scope is advanced. Inside the joint, we can see here the slack anterior cruciate ligament (ACL) due to posterior tibial sag.
Using a shaver device, we debrided the residual PCL graft.
Here, we see the entry point of the old tunnel.
Over the guide pin, we drilled 4.5 mm and then 9 mm outside-in to clean the old 8-mm tunnel measured on the preoperative computed tomography (CT) scan.
We can see here the semi-anatomic position of the tunnel that is far from the cartilage border and where the entry point of the anatomic one should be positioned, closer to the roof of the notch and tangent to the articular cartilage.
A cancellous bone plug 9 mm in diameter is impacted along the previously inserted guide pin.
Arthroscopy is used to check that the allograft is flush with the articular surface.
Here, we can see again the difference between the entry point of the old tunnel and where the exact entry point of the anatomic tunnel should be.
Through the anterolateral portal and with the inside-out instrumentation, a guide pin is placed on the new PCL footprint.
A new anatomic femoral socket is then drilled with a cannulated drill bit of 9 mm for a 15-mm length.
Using the scope, we confirmed the presence of bone around the entire tunnel with no convergence with the old one, to ensure good fixation.
Here, we see the previous tunnel fill with the bone plug allograft and the new one.
The next step was to prepare the transeptal portals.
The scope is advanced into the posteromedial (PM) compartment through the intercondylar notch. The PM capsule is viewed. An 18-gauge spinal needle is inserted along the posterior edge of the medial condyle and 5 mm above the tibial articular surface. The entry point of the PM portal is then created with a blade on the needle path. A shaver is introduced first to clean and debride the PM compartment.
Then the posterior septum was perforated via the PM portal using a blunt obturator and its sheath. The posterolateral (PL) portal is created under direct visualization by a skin incision.
The shaver was introduced through this PL portal to expose the PCL tibial attachment site completely.
We detached the posterior capsule from the PCL remnant and debrided the posterior compartment.
The tibial guide is put in place through the anteromedial (AM) portal and the old medial incision.
Here, we can see the correct positioning of the PCL tibial guide and the popliteus muscle.
A guide pin is inserted first into the new tibial tunnel, ignoring the trajectory of the existing one.
Drilling started with a 5-mm-diameter bit and then increased to 9 mm, the size of the graft, while maintaining the tibial guide in place to protect the posterior neurovascular bundle.
We then checked that the tunnel is complete.
We passed a suture loop into tibial tunnel and retrieved it through the AM portal.
Here, we see two sutures loop in both tibial and femoral tunnels.
Using a suture retriever, we coupled the femoral loop to the tibial one and passed it through the tibial tunnel, to get one suture loop passing both tunnels.
Using this suture loop, we passed the graft from distal to proximal, by the tibial tunnel and then in the femoral one.
The graft is first passed into the femoral socket. Once the button passed the depth of the femoral tunnel, the adjustable button flipped on the lateral femoral cortex.
The shortening sutures are pulled in an alternating fashion to lift the graft into this femoral socket for secure fixation.
Then the tibial end of the graft is fixed with 2 interference screws inserted over the guide pin, with maximum tension on it, in 90° of knee flexion, starting with the proximal one, and then the distal one.
Finally, we added a backup fixation using an anchor to secure the free ends of the internal brace. A guide pin is drilled 1.5 cm distal to the tibial tunnel and reamed with a 4.5-mm reamer to a depth of 20 mm. Then, the fiber tape is fixated with knotless absorbable Biocomposite SwiveLock (Arthrex) to additionally tension the construct.
The scope is reinserted to confirm the solid PCL, and we can see that the ACL has regained its tightness after correction of the posterior tibial sag.
On a postoperative sagittal CT scan, we can see the new femoral and tibial tunnels that have been made.
On this axial femoral cut, we can see the initial tunnel filled with the allograft plug and the revised tunnel, with no convergence between them.
On this sagittal tibial cut, we can see the initial nonanatomic tunnel on the left side and the new tibial tunnel with both interference screws.
The potential complications for this type of procedure include the following:
Neurovascular bundle injury that can be avoided by using the posterior transeptal approach
Convergence of tunnels which is minimized by using an allograft bone plug to fill the old femoral tunnel and drilling a new tibial tunnel at distance from the original nonanatomic one
Fixation failure that can be avoided by checking that the femoral cortical button is at distance from the initial tunnel and well seated on the femoral cortex, and by using intratunnel tibial fixation with the addition of a backup fixation on the cortex
For the postoperative rehabilitation protocol:
In phase 1: We have the RICE (rest, ice, compression, elevation) protocol, no weightbearing, passive range of motion (ROM) between 0° and 90° in prone position for the first 2 weeks than as tolerated
In phase 2: Progressive weightbearing as tolerated, full ROM in prone and supine positions, muscle strengthening but not more than 70° of flexion
In phase 3: We start strengthening exercise for the hamstring and active flexion more than 70°
In phase 4: Advanced strengthening and proprioceptive exercises, ligament evaluation with stress radiography, and hinge brace removed at 24 weeks postoperatively
In the last phase, patient education and gradual return to activities
The expected outcomes are as follows:
Satisfactory results with 75% of patients returned to preinjury Tegner activity level2,4
Significant relief in pain, stability, and function 5
Significant improved side-to-side differences on stress Xrays and improved subjective and objective clinical scores 7
Finally, keep in mind the following:
The posterior transeptal portal approach allows good visualization of the tibial tunnel preparation and protects the vital neurovascular structures 5
Allograft bone plugs facilitate revision in the one-stage procedure 11
Internal brace augmentation protects the graft during the revascularization and remodeling process 12
Backup fixation is essential due to compromised bone stock in revision surgeries 4
Here are our references.
Thank you for watching this video.
Footnotes
Submitted February 20, 2023; accepted May 17, 2023.
One or more of the authors has declared the following potential conflict of interest or source of funding: E.C. is a paid consultant for Arthrex. 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.