Arthroscopic Suture Fixation of Tibial Eminence Fracture

Abstract

Background:

Tibial eminence fractures account for up to 5% of knee injuries with an effusion in the pediatric population. Displaced fractures require reduction and operative fixation via arthroscopic or open techniques.

Indications:

Arthroscopic suture fixation and screw fixation are 2 of the most commonly described techniques for tibial eminence fracture treatment. We describe our preferred technique of arthroscopic suture fixation given the versatility of this technique and decreased risks of hardware irritation or impingement, need for reoperation, and minimal risk of physeal damage.

Technique Description:

The arthroscopic suture fixation technique uses a standard anteromedial and anterolateral portal. After the fracture bed and hematoma are debrided and any interposing structures (ie, meniscus) are removed from the fracture site, 2 nonabsorbable sutures are passed through the substance of the anterior cruciate ligament (ACL). Using an ACL guide, 2 separate transtibial tunnels are drilled with a bone bridge in between—one at the anterolateral aspect of the fracture base and one at the anteromedial aspect. One limb from each suture is pulled out from each of the bone tunnels. The fragment is then reduced, and the sutures are tensioned and fixated using knotless suture anchors.

Results:

Overall prognosis following tibial eminence fracture fixation is favorable with more than 80% of patients returning to prior level of activity. Arthrofibrosis may occur in up to 25% of patients. Although some residual laxity may remain, there is a high return to sport and no difference in rate of subsequent ACL injury or surgery compared with a match cohort of pediatric ACL reconstructions.

Discussion:

Arthroscopic suture fixation of displaced tibial eminence fractures is a reliable technique with high return to sport and low risk of reoperation. Arthrofibrosis is common; thus, early, controlled knee range of motion following surgery is critical.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

This is Dustin Richter and Gehron Treme from the University of New Mexico describing our technique for the arthroscopic suture fixation of tibial eminence fractures.

These are our disclosures: The authors receive fellowship educational support from Arthrex, Smith & Nephew, and Stryker.

Tibial eminence fracture is synonymous with tibial spine fracture. It is an intra-articular fracture of the bony attachment of the anterior cruciate ligament (ACL). This is an intra-operative photograph demonstrating the ACL inserting on the tibial eminence uninjured; however, the tibial eminence fracture is displaced and pulling off the proximal tibia. The medial condyle is presented for reference.

During this presentation, we will discuss how the typical patient presents as well as evaluation. We will go over surgical treatment indications, preoperative planning, and then show our video on arthroscopic suture fixation of tibial eminence fracture. We will discuss some of the pearls and pitfalls, as well as postoperative rehabilitation protocol and return to sport criteria. Finally, we will conclude with some patient outcomes data.

Most commonly, tibial eminence fractures are seen in children between the ages of 8 and 14 years of age and are usually associated with athletic activity. The mechanism is similar to that which causes an ACL tear with hyperextension and rotation of the knee. Our case is of a 10-year-old boy who tripped and fell while running. He was sent from an outside facility. On physical examination, he had a moderate effusion. He had laxity with Lachman examination; however, his other ligaments were stable and he was neurovascularly intact. Notably, he lacked full range of motion with a 15° lack of full extension. For imaging, we obtained radiographs. The patient came with a magnetic resonance imaging (MRI). Although MRIs are not critical as imaging typically will show the displaced tibial eminence fracture, they can give indications of any associated pathology.

These are anteroposterior and lateral radiographs of the patient’s left knee demonstrating the displaced Type 3 tibial eminence fracture.

On the MRI, the displaced tibial eminence fracture can be seen better. The ACL inserts uninjured onto the displaced fragment of the tibial eminence.

Surgery or nonoperative treatment can be undertaken. Nonoperative treatment is typically reserved for nondisplaced fractures or those that are Type 2 fractures, which are minimally displaced with an intact posterior hinge and can be reduced in full extension. Operative indications, which is the focus of this technique, are for completely displaced and/or rotated fractures. Usually the patient has a block to full extension, which can indicate that the fracture is not able to be fully reduced due to an entrapped meniscus or intermeniscal ligament.

For preoperative planning, several surgical techniques are described but the 2 most common are arthroscopic suture fixation or screw fixation via an arthroscopic or open approach. Screw fixation may be less technically demanding; however, a larger, non-comminuted fracture fragment is usually required. Some of the potential complications include hardware irritation or impingement requiring screw removal and a greater risk of damage to the proximal tibia physis. Arthroscopic suture fixation is technically more challenging; however, it can be used for a variety of fragments including larger fragments or smaller, comminuted fragments, and there is smaller risk of damage to the physis.

Patient positioning is up to the surgeon’s discretion. However, we use 2 anterior portals, with an anteromedial and an anterolateral.

In this video, we will demonstrate an arthroscopic reduction and fixation of a tibial eminence fracture. You will see the fracture here with fracture extending into the medial compartment and the medial meniscus anterior horn trapped beneath the fracture fragment. The anterior soft tissues are removed with a shaver. The organizing hematoma within the fracture site must also be removed to allow reduction. You can see that this has been removed, taking care to protect the bone on the actual fragment. The anterior horn of the medial meniscus is seen here blocking reduction, and this will have to be removed from the fracture site once the fracture is reduced, but it will be left there for now. The lateral meniscus is attached to the fracture fragment; that is typical, as seen here. A scorpion suture passer is used to pass suture around the ACL. Two No. 2 sutures are placed. It is nice to have them different colors, they are easier to manage that way. Once the sutures are passed, control is then gained of the ligament. No sutures are put through the bone. One set of sutures will be crossed in front of the ligament. The other will not be crossed. So the selected sutures are secured here with a grasper and pulled into the portal. An ACL guide is used to place a standard drill pin followed by a spinal needle and a prolene in the front of the fracture bed. That prolene is then pulled out into the same portal that the sutures were shuttled into, and the sutures are then shuttled down through that drill hole.

Next, a guide pin is placed in the anterolateral aspect of the fracture site in a similar fashion, followed by a spinal needle and a prolene. The other set of sutures is then shuttled down through this drill tunnel. These drill tunnels are fairly short because they are so anterior. Once the sutures are shuttled down then they can be placed at various spots on the fracture fragment. To affect the reduction that is desired, the meniscus is pulled out of the way, and then the fracture is reduced with sequential tensioning of the sutures. Once the sutures are tensioned and the fracture is reduced acceptably, as seen here with a nice reduction of the chondral surface and the meniscus being freed from the fracture site, the sutures can be tied over the bone bridge and then backed up on the tibia with a knotless suture anchor.

Postoperative radiographs demonstrate reduction and fixation of the fracture.

Postoperative MRI is typically not obtained; however, this patient did have arthrofibrosis approximately 2.5 months after surgery. The image demonstrates the transtibial suture tunnels that were used as well as the reduction of the fracture fragment. The ACL is intact and there is scarring and a cyclops lesion just anterior to the ACL.

Some of the pearls to avoid complication involve getting to these types of injuries early to avoid any kind of malunion or excessive scar tissue. Debriding the fracture hematoma and even slightly recessing the fracture base is critical to allow appropriate reduction. Visualizing the entire meniscus is important as well. Typically, the lateral meniscus will still attach to the fracture fragment anteriorly, whereas the medial meniscus is more likely to be incarcerated under the fracture fragment. Sequentially tensioning and repositioning the sutures as needed for optimal fracture fixation as shown in the video. And very important is after a short period of initial immobilization, controlled range of motion should be started to avoid developing excessive stiffness.

Our postoperative rehabilitation protocol and return to sports mimics that seen for ACL injuries. We typically brace the patient in extension for 10 to 14 days to allow them to obtain and keep their full extension. We then begin early, controlled range of motion to decrease the likelihood of arthrofibrosis and progressive weight-bearing. Return to sport is on average around 6 months after surgery, which is usually 3 to 4 months earlier than an ACL reconstruction patient.

On a review of clinical outcomes, this 10-site multicenter study looked at risk factors for the development of arthrofibrosis. They had approximately 250 patients <18 years old. Nearly one-quarter of them developed postoperative arthrofibrosis. Four risk factors were identified including age younger than 10 years of age, trauma-related nonsporting injury, cast immobilization following surgery, and concomitant ACL injury.

The group out of Boston Children’s evaluated suture versus screw fixation for tibial spine fractures. They evaluated 68 knees, and they noted that clinical outcomes were equivalent between the 2 groups. However, the screw fixation group had an odds ratio of nearly 3.0 with more operations required in the screw fixation group and most of these being implant removals. The suture fixation group had more postoperative elevation of the repaired fragment on postoperative imaging, but this did not negatively affect the surgical outcome.

Finally, how do tibial eminence fractures fare compared with isolated ACL tears? The group out of Mayo Clinic examined 20 patients with tibial eminence fractures with a minimum 2-year follow-up and a mean age of almost 12 years old. They compared them in a 2:1 matched cohort of patients similarly aged who underwent isolated ACL reconstruction. The tibial eminence fixation group was noted to have lower International Knee Documentation Committee and Lysholm scores; however, this did not meet the minimal clinically important difference. In the eminence fixation group, there was more postoperative anterior laxity and also a higher rate of arthrofibrosis. However, return to sport was approximately 4 months earlier than the ACL reconstruction group. There was no difference between the 2 groups in rate of subsequent ACL injuries needing surgery.

These are our references, and thank you for your attention.