Arthroscopic Repair of Bony Avulsions of Both Cruciate Ligaments and Both Posterior Meniscal Roots

Case

The patient in this case is a 58-year-old woman who sustained a fall from her bike. She presented in the emergency room with pain and instability. The physical examination revealed soft compartments and an ankle-brachial index >1. Additionally, instability testing in the emergency room revealed gross anteroposterior laxity. Radiographs showed a large posterior tibia plateau fracture around the PCL and posterior subluxation. Computed tomography series confirmed a large osseous avulsion of the PCL with small osseous fragments suggesting an ACL avulsion, and suspicion that the medial and lateral posterior roots were involved in the osseous avulsions, which were visualized with 3-dimensional images. Magnetic resonance imaging showed attachment of the medial and lateral posterior roots to the osseous avulsions along with the PCL and a distal avulsion of the ACL. It also showed a partial tear of the femoral medial collateral ligament (MCL). Stability testing under anesthesia showed 3+ Lachman, 3+ anterior and posterior drawer tests, 3+ pivot shift, 1+ valgus instability at full extension and 2+ at 30° of flexion, and stable to varus stress.

Preoperative Planning and Positioning

Preoperative planning consisted of starting with a diagnostic arthroscopy, which is preferred to be performed within 2 to 3 weeks to avoid fluid extravasation, while still allowing for minimal callus formation, and the repair of both meniscus root tears using a transosseous technique. Given the multiple fragments, open posterior fixation with a screw was not considered feasible. The PCL would then be repaired in a transosseous fashion if the tissue quality was good; otherwise, an allograft PCL reconstruction would be performed. This was similar for the ACL. After the cruciates have been stabilized, the MCL injury is a partial isolated injury, which has been shown to heal reliably in ACL-MCL injuries and was therefore left alone.^4,12,15 Positioning was supine with a tourniquet up high on the femur and a post for appropriate valgus stress.

Diagnostic Arthroscopy

First, a diagnostic arthroscopy of the right knee was performed. Here, we see the distal avulsion of the ACL. Then we see medially a bony fragment with cartilage that is flipped near the posterior medial root, and the posterior medial root is avulsed with the fragment. Also note the positive drive-through sign, which was noted on the medial side, corresponding with the MCL injury. After debridement of callus and scar tissue, it can be noted that the PCL and the lateral meniscus posterior root are also avulsed with bone below the insertions, and that the bone fragments also have cartilage attached to them.

Posterior Cruciate Ligament Repair

First, No. 2 TigerWire and FiberWire sutures (Arthrex) are passed through the distal tissue of the PCL using a Scorpion suture passer (Arthrex). These are not passed through the bony but through the PCL just proximal to the bony fragment. This is then repeated with No. 2 FiberWire sutures. The PCL footprint is then cleaned of any callus or debris, and the tibial PCL drill guide is inserted into the PCL footprint underneath the large bony fragment. A 2.4-mm drill guide is then used to drill up into the insertion of the PCL. The red straw with FiberStick suture is used to shuttle the PCL sutures through the drill hole. This reduces the bony fragment and tensions the PCL.

Medial Meniscus Root Repair

The attention is then turned to the medial meniscus. The drill guide for the meniscus root is then placed over the middle of the cartilage fragment that corresponds to the medial meniscus root insertion, and a 2.4-mm drill guide is then drilled. The center sleeve is removed, and a nitinol wire is then placed and retrieved using a ring grasper (Suture Retriever; Arthrex). The nitinol wire is then retrieved through the anteromedial portal. A Scorpion suture passer is then used to first place a No. 2 FiberLink through the medial meniscus in luggage tag fashion. This is then repeated with a No. 2 TigerLink suture. The suture passer should be angled away from the medial femoral condyle when passing the suture to avoid damage to the cartilage. One can also use the suture passer to determine the best location for the meniscal tissue. The sutures are now shuttled through the tibial tunnel, and the medial meniscus and large cartilage fragment are now tensioned to the tibia.

Lateral Meniscus Root Repair

The lateral meniscus root is then repaired similarly. Previously, 2 No. 2 TigerLinks have been passed through the lateral meniscus in luggage tag fashion, similar to the medial meniscus root, as previously shown. A 2.4-mm tunnel is then similarly drilled from the anterolateral tibia to the medial side, and the nitinol wire is used to shuttle both lateral meniscal sutures through the tibial tunnel.

Anterior Cruciate Ligament Repair

Using a Scorpion suture passer, 2 sutures are passed through the distal part of the ACL. Here, one of the sutures of 1.3-mm FiberLink suture tapes is shown, which is passed through the distal ACL in luggage tag fashion, and care is taken not to damage the lateral femoral condyle. A tunnel is then drilled in the medial part of the ACL footprint, and a nitinol wire is used to shuttle the first TigerLink tape. A second, more lateral 2.4-mm drill tunnel is then drilled in the more anterolateral part of the footprint, and the sutures are passed through the tunnel. The ACL is tensioned, which also involves the attached anterolateral root of the lateral meniscus.

Now, both meniscus roots are fixed with the knee in 30° of flexion using two 4.75-mm vented BioComposite SwiveLocks (Arthrex) on the anterolateral tibia. Similarly, both cruciate ligaments are fixed using a 4.75-mm Vented BioComposite SwiveLock (Arthrex) on the anteromedial tibia approximately 1 cm below the exit of their tunnel. The PCL is fixed first with the knee in 90° of flexion while maintaining an anterior drawer force, and the ACL is then fixed with the knee in 20° of flexion while maintaining a posterior drawer force.

Final Inspection

Final inspection reveals good tension of the ACL when using the probe, good position of the medial meniscus, good fixation of the posterior root, and a well-positioned lateral meniscus root. Stability testing revealed a stable Lachman, and anterior and posterior drawer tests, and the MCL instability was grade 0 in full extension and 1+ in 30° of flexion, and this was left to heal, as proximal tears have been shown to have excellent healing capacity. ¹⁵

Pearls of this technique are the optimal time window of 2 to 3 weeks, to review preoperative imaging critically for potential repair, to consent patients preoperatively for repair versus reconstruction, and to drill the lateral meniscus tunnel from the anterolateral tibia and the medial meniscus tunnel from the anteromedial tibia to avoid tunnel convergence. Pitfalls to avoid include opening or harvesting grafts before confirmation of possible preservation and making tunnels too close to each other.

Rehabilitation

Weightbearing is limited for the first 6 weeks and is then gradually progressed to full weightbearing. The knee is locked in the brace for 1 week, and range of motion is then progressed from 0° to 90° over the next 5 weeks, during which a varus/valgus stabilizing brace is worn. After 6 weeks, a full range of motion is allowed, and a PCL rebound brace is worn to prevent stretching of the PCL repair. A standard multiligamentous knee reconstruction protocol is followed, and return to sports is allowed at a minimum of 1 year.

Case Follow-up

At 1-year follow-up, our patient reported a Single Assessment Numeric Evaluation score of 90 and a visual analog scale pain score of 0. She was overall very satisfied but reported occasional stiffness after running. She had a full range of motion and a stable knee with examination. Radiographs revealed union at 3 months and no signs of osteoarthritis at 1-year follow-up.