Primary MCL Repair Following Distal Avulsion: A Technique Video

Abstract

Background:

The medial collateral ligament (MCL) is the most frequently injured knee ligament, accounting for approximately 8% of all knee injuries. This video presents a reproducible method for MCL repair.

Indications:

Grade 1, grade 2, and proximal grade 3 MCL tears with no concomitant injuries are managed nonoperatively with a hinged knee brace and physical therapy. Complete, distal MCL tears, often presenting as Stener-like lesions, warrant surgical intervention due to their tendency for inadequate healing with conservative measures.

Technique Description:

An 8-cm incision is made centered over the pes tendons a finger breath lateral to the posterior medial border of the tibia. Full-thickness medial and lateral soft tissue flaps are made sharply, exposing the sartorial fascia. An L-shaped incision is made through the fascia, proximal to the hamstring tendons and superiorly and just medial to the tibial tubercle. The superficial MCL is visualized, lifted off the tibia with a Cobb elevator, and captured with 2 suture tapes in a whipstitch fashion. A relatively isometric MCL insertion point is identified, unicortically drilled, and tapped for a suture anchor. The suture tapes are loaded into the anchor, tensioned, and screwed into position with the knee flexed between 10° and 30°. The 2 separate suture tapes are tied together to reinforce fixation, and the anterior margin of the MCL is then sutured to the periosteum to reinforce the repair.

Results:

The patient returned to full function and activity after 6 months. Repair of acute MCL injuries is known to show favorable outcomes. There are currently no published data on the specific MCL repair technique presented in this level 5 evidence video.

Discussion/Conclusion:

Repair of distal MCL avulsions can be technically challenging. The technique presented is a reproducible method for MCL repair. Earlier surgical intervention may optimize outcomes and obviate the need for allograft 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.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

We present our technique for primary medial collateral ligament (MCL) repair following distal avulsion. The authors have no relevant disclosures for this presentation. This is an overview of our presentation.

Background

The MCL is the most commonly injured knee ligament, accounting for about 8% of all knee injuries. ⁷ MCL injuries typically occur secondary to valgus blow or dislocations.

Physical examination findings help classify the degree of MCL injury. ³ LaPrade et al ⁵ in 2010 reported that a side-to-side difference in medial gapping on stress radiographs greater than 3.2 mm should raise suspicion for a complete MCL tear.

Most MCL tears are managed nonoperatively due to the extra-articular nature of the ligament, which is perfused by a rich vascular supply for healing. Indications for nonoperative management include grade 1 and 2 tears, as well as grade 3 tears that are proximal, are mid-substance, or do not associate with any concomitant injuries. ⁸ Nonoperative treatment generally entails using a hinged knee brace to prevent valgus stress and physical therapy to restore range of motion and build strength.

Complete distal MCL tears are commonly indicated for surgical intervention. ² Injuries of the tibial attachment site are particularly prone to poor healing with conservative measures due to the Stener-like lesion that often results. ¹

When surgical intervention is indicated, there are 2 main treatment options: repair versus reconstruction. Repair is preferred in the acute setting with a distal avulsion injury where adequate tissue and quality are anticipated. Reconstruction is recommended for chronic injuries, injuries with insufficient tissue for repair, and revisions. We do not generally add suture tape augmentation to our repairs, but this has previously been described as a technique to potentially allow a more accelerated rehabilitation protocol. ¹¹

Indications

We present a case of a 26-year-old man who sustained a left valgus knee injury while snowboarding. In the office, he noted medial side and knee pain, swelling, and stiffness.

On examination, he was tender to palpation over the medial joint line and the course of the MCL. Ligamentous testing revealed a 2-plus laxity and pain during valgus stress at 30° of flexion while remaining stable to varus stress.

Standing anteroposterior and lateral radiographs of the left knee were obtained and were normal.

Magnetic resonance imaging was then obtained of the left knee. On coronal imaging, the superficial MCL tibial attachment site is torn with no interposed tissue suggestive of a Stener-type lesion. The pes tendons can be seen just superficial to the MCL. An axial cut demonstrates the same findings.

Technique Description

For our MCL repair technique, we position the patient supine without placing a bump under the operative leg. A thigh tourniquet is applied before prepping and draping, and the lateral post is placed on the bed for diagnostic arthroscopy before repair.

To evaluate for concomitant pathology, an examination under anesthesia is performed, including evaluation of the arc of motion, which in this case is full. Medial gapping with valgus stress at 30° of knee flexion and an anterior medial drawer test are performed, with the lower leg externally rotated and the knee in 90° of flexion to evaluate for superficial MCL and concomitant posterior oblique ligament injury. The examination under anesthesia is notable for greater than 10-mm side-to-side laxity with valgus stress at 30° of knee flexion.

Diagnostic arthroscopy is performed. Viewing the medial compartment, evidence of a drive-through sign can be seen, consistent with MCL injury. No concomitant interarticular pathology is identified. With valgus stress, the meniscus displaces superiorly within the medial compartment consistent with a distal-sided MCL injury.

Attention is turned to the open MCL repair. The pes tendons are palpated and marked, and the posterior border of the tibia and joint line are used as landmarks for incision. We prefer to make an 8-cm incision centered over the pes tendons, a finger breadth lateral to the posterior medial border of the tibia. Full-thickness, medial, and lateral soft tissue flaps are made sharply, and the sartorial fascia is identified. An L-shaped incision is then made through the sartorial fascia with the horizontal limb and just proximal to the hamstring tendons and the corner more laterally near the tibial tubercle. We typically make the lateral vertical limb of the fasciotomy first and dissect the horizontal limb with Metz scissors. It is important to leave a 1-cm cuff of fascial tissue more laterally for repair at the end of the case. The sartorial fascia, with the semitendinosus and gracilis tendons attached to the posterior aspect, is retracted, and the superficial MCL, bulging, can now be visualized on the floor of the pes anserine.

A Cobb elevator is used to lift the superficial MCL tissue off the tibia, where it is scarred more proximately. An Ethibond (Ethicon) stitch is used to tag the pes tendons for retraction and later repair at the end of the case. Next, two 1.3-mm suture tape sutures are used to capture the MCL tissue in a whipstitch fashion. The distal MCL insertion is identified 6 cm distal to the joint line. ⁶ A relatively isometric point of the MCL is identified by holding the suture tapes and ranging the knee from 10° to 30° of flexion. Once the precise location for suture anchor insertion is identified, a 3.5-mm drill bit is unicortically drilled at this location. The hole is tapped for a 4.75-mm polyether ether ketone suture anchor. The suture tapes are loaded into the suture anchor and tensioned, and the anchor is placed and screwed into position, tensioning the construct with the knee in between 10° and 30° of flexion with a gentle varus load to reduce the medial compartment. The 2 separate suture tapes are then tied together with 5 alternating half-hitches to reinforce fixation. Stability is then checked by applying a gentle valgus stress with the knee flexed 30°. The anterior margin of the MCL is then repaired to the periosteum more laterally with inverted No. 2 Ethibond sutures, and the proximal horizontal limb is closed with 0 Vicryl suture. The arthroscope is then reintroduced, and a gentle valgus stress is applied while viewing the medial compartment. Medial gapping that was present prior to repair of the MCL has now been reduced, with reversal of the drive-through sign.

Pearls for this technique include taking down the pes tendons to clearly expose the distal superficial MCL footprint. We prefer to do this in an L fashion, leaving a 1-cm cuff of tissue laterally to repair the sartorial fascia with a No. 2 nonabsorbable suture. It is important when using the suture tapes to make sure to capture most extents of both the anterior and posterior distal superficial MCL, recognizing the ligament is relatively broad distally. To identify the location for suture anchor placement, range the knee from 10° to 30° of flexion while tensioning the suture tapes with the knee in neutral rotation. This should help to identify the most isometric point for anchor insertion. Before insertion, ensure the knee is flexed 10° to 30°, in neutral rotation, and that the ligament is appropriately tensioned. ⁴ We recommend performing this repair technique within 4 weeks from the time of injury. Pitfalls of this technique include leaving prominent hardware and nonabsorbable sutures in place, which can irritate the pes tendons. If pes irritation does occur, we recommend use of anti-inflammatories, voltaren gel, and, once the MCL has healed after 3 months, a single corticosteroid injection, if necessary.

Results

Our postoperative rehabilitation protocol is detailed here. In brief, immediately following surgery, patients are placed in a hinged knee brace locked in full extension and remain nonweightbearing for 6 weeks. Starting at week 3, active assisted range of motion from 0° to 30° is initiated. From 6 to 12 weeks, patients progress to full motion, and the unlocked hinge knee brace is continued with activities. From 3 to 4 months, patients practice step-downs and mini-squats. At 5 months, patients begin running agility- and sport-specific activities. This protocol may be accelerated in competitive athletes who return to sports at 4 months postoperatively. In the setting of concomitant anterior cruciate ligament reconstruction or meniscus repair, the first 4 months of the rehabilitation protocol are unchanged. In the setting of concomitant anterior cruciate ligament reconstruction, return to sport is typically 9 months postoperatively. Postoperative arthrofibrosis has been shown by Mowers et al ⁹ to range from 0% to 20% following MCL repair. We have not had frequent issues with postoperative stiffness with our rehabilitation protocol.

Thompson et al ¹⁰ published a case series of distal MCL repairs in elite athletes. Ten athletes sustained isolated distal MCL injuries that were repaired without augmentation, similar to the present technique. All 10 athletes reported function comparable to preinjury levels at 6 and 24 months, taking an average of 17 weeks to return to sports.

Discussion/Conclusion

In summary, repair of distal MCL evolutions can be technically challenging. The technique that we present is a reproducible method for MCL repair. Earlier surgical intervention may optimize outcomes and obviate the need for allograft reconstruction.

These are references. Thank you for taking the time to watch our video.