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

Abstract

Background:

Injury to both cruciate ligaments and both posterior meniscus roots occurs in multiligamentous knee injuries; nonetheless, osseous avulsion-type injuries of these structures are rare. This study outlines the surgical technique for anatomically repairing these structures while preserving the surrounding cartilage fragments.

Indications:

Distal osseous avulsions of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial and/or lateral meniscus posterior root tears (MMPRT and LMPRT).

Technique Description:

Arthroscopic primary repair of the ACL, PCL, MMPRT, and LMPRT is performed using a transtibial technique in a unique case of the combination of osseous avulsions of these 4 structures.

Results:

Primary repair of distal ACL and PCL osseous avulsions has been described, with overall encouraging results. ACL fixation leads to a negative Lachman in most cases, and PCL fixation leads to reliable posterior translation and an excellent return to sport, as reported in a recent systematic review. Outcomes of osseous root repairs in the literature are scarce, but are expected to be similar to those of meniscus tissue root tears, which have been shown to delay or prevent osteoarthritis and the need for knee arthroplasty compared with nonoperative treatment or meniscectomy.

Discussion/Conclusion:

Early arthroscopic treatment of these osseous avulsions enables surgeons to assess all concomitant injuries, to remove callus and healing tissue, and perform anatomic repairs of the avulsed ligaments and menisci. Anatomic repair has the potential to provide excellent results with low surgical morbidity and good outcomes.

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.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcripts

This video demonstrates the surgical technique for arthroscopic repair of osseous avulsions of both cruciate ligaments and both posterior meniscus roots.

In this video, we will discuss the unique case of osseous avulsions of both meniscus roots and both cruciate ligaments. We will discuss the surgical technique, follow-up of the case, and outcomes in the literature.

Background

The role of the medial and lateral meniscus is generally well understood with shock absorption, secondary stabilization,^13,14 and the chondroprotective role to prevent osteoarthritis.^7,20

Generally, medial meniscus posterior root tears (MMPRTs) occur in the degenerative knee after often minor trauma, whereas lateral meniscus posterior root tears (LMPRTs) most commonly occur in the knee with an anterior cruciate ligament (ACL) injury. ⁶ However, suspicion for both is warranted in all injuries as LMPRTs can be missed, and MMPRTs can also occur in the traumatic ligament-injured knee.^5,8 It is rare for meniscus root tears to occur as bony avulsions,^2,8 and this is similar for the cruciate ligaments, which only occur in approximately 2% of ACL injuries^10,11 and 4% of posterior cruciate ligament (PCL) injuries ¹⁹ in adults.

In this case, we present a surgical technique involving osseous avulsions of the MMPRT and LMPRT, as well as osseous distal avulsions of the ACL and PCL, which were all repaired arthroscopically.

Indications

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.

Technique Description

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.

Results

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.

Discussion/Conclusion

Osseous avulsions of the addressed structures are rare. ACL tibial avulsions are estimated to occur in only 2% of adult ACL tears,^10,11 and the outcomes in the literature are generally favorable, with 82% exhibiting a negative Lachman test and good patient-reported outcomes. ¹ PCL tibial avulsions are estimated to only occur in 4% of cases, ¹⁹ and are reported to have excellent side-to-side stability and full return to sport in all patients. ³

Osseous avulsions of medial meniscus root tears have been estimated to occur in only 3% of all root tears,^2,5,8 and general outcomes of medial meniscus root repair have been reported to be superior to meniscectomy or nonoperative treatment. ⁹ Osseous lateral meniscus root avulsions have been reported to be even rarer, with only 3 cases in the literature,^2,8 and repairing lateral meniscus root tears is important to control rotatory stability and avoid long-term osteoarthritis.^13,16-18

This video highlighted the surgical technique of transtibial repair of the rare case of bony avulsions of both cruciate ligaments and both posterior meniscal roots, and the outcomes have been reported to be encouraging in level 4 evidence. Repair of bony avulsions can be considered when the menisci or ligaments themselves are intact.