Abstract:
Tibial avulsion fractures comprise a subset of anterior cruciate ligament injuries. Primary fixation methods have traditionally used either screw or suture fixation. New anchor and suture technologies have led to the development of tensionable and retensionable techniques. These newer techniques allow for not only anatomic reduction but also further compression after reduction. The purpose of this technical note is to introduce a tensionable and retensionable construct that uses knotless anchor fixation to produce compression after anatomic reduction of a tibial avulsion fracture.
Introduction
Anterior cruciate ligament (ACL) injuries are on the rise in the pediatric and adolescent patient populations, with incidence rates peaking at age 16 years for female patients and at age 17 years for male patients.1 Diagnosis and treatment of these injuries can be more challenging in these populations compared with their adult counterparts owing to the spectrum of injuries that can arise from pediatric or adolescent ACL injury. Tibial avulsion or eminence fractures most often present in the pediatric or adolescent population but can also occur in the adult population.2 The mechanism of injury is thought to occur when a hyperextended knee simultaneously undergoes rotation on the tibia (e.g., a twisting injury while playing soccer or falling off a bicycle).3 Historically, these injuries have been classified according to a system developed by Meyers and McKeever,4 with types I, II, and III defined by varying degrees of dislodgement of the avulsed fragment.
The primary fixation methods used to treat tibial avulsion fractures have involved either screw or suture fixation. Chang et al.5 conducted a meta-analysis comparing the clinical and functional outcomes between arthroscopic screw fixation and suture fixation for tibial avulsion fractures. The differences in clinical outcomes between the 2 methods were inconclusive.5 A previous study investigated the load-to-failure outcomes across 3 fixation methods for tibial eminence fractures that included an anchor fixation method in addition to the more commonly used screw and suture fixation methods.6 The anchor fixation group showed a statistically significantly higher mean ultimate failure load.6
Newer anchor and suture technologies have led to the development of tensionable and retensionable techniques. These newer techniques allow for not only anatomic reduction but also further compression after reduction. The purpose of this technical note is to introduce a technique that uses knotless anchors to produce compression after anatomic reduction of tibial avulsion fractures. Our fixation method has the potential to improve functional outcomes and reduce reoperation rates in this patient population.
Authors:
Khay-Yong Saw, M.Ch.Orth., F.R.C.S.(Edin),
Adam Anz, M.D.,
Shahrin Merican, M.B.B.Ch., F.R.C.R.,
Yong-Guan Tay, M.S.Orth., F.R.C.S.(Edin),
Kunaseegaran Ragavanaidu, M.B.B.S., M.Path.,
Caroline S. Y. Jee, Ph.D.(Lond),
and David A. McGuire, M.D.
From the Kuala Lumpur Sports Medicine Centre (K-Y.S., S.M., Y-G.T.), Kuala Lumpur; Clinipath (K.R.), Klang, and Universiti Tunku Abdul Rahman (C.S.Y.J.), Kuala Lumpur, Malaysia; Wake Forest University Baptist Medical Center (A.A.), Winston-Salem, North Carolina; and Alaska Surgery Center (D.A.M.), Anchorage, Alaska, U.S.A. The authors report no conflict of interest. Received June 21, 2010; accepted November 10, 2010. Address correspondence to Khay-Yong Saw, M.Ch.Orth., F.R.C.S.(Edin), Kuala Lumpur Sports Medicine Centre, 7th Floor, Wisma Perintis, 47 Jalan Dungun, Damansara Heights, 50490 Kuala Lumpur, Malaysia. E-mail: sportsclinic@hotmail.com © 2011 by the Arthroscopy Association of North America
For personal use only. No other uses without permission. Copyright ©2021. Elsevier Inc. All rights reserved.
Surgical Technique
We describe our step-by-step technique for ACL tibial avulsion fracture fixation using a tensionable and retensionable suture anchor construct (Video 1). Informed consent was obtained from all patients prior to undergoing the surgical procedure described in this article. Advantages and limitations of the technique are described in Table 1, and technical pearls and pitfalls are summarized in Table 2.
Indications
This surgical technique is indicated in patients with a type II, III, or IV tibial eminence fracture who also present with clinical evidence on examination or symptoms of an incompetent ACL.
| Advantages |
| The technique allows for both reduction and compression of the avulsed fragment. |
| The technique allows for tension and retensioning of the compression construct. |
| The security of the construct is not dependent on 1 anchor. |
| Limitations |
| Variable anatomy can make placement of the knotless FiberTak anchors difficult. |
Patient Examination and Imaging
A thorough history and physical examination are required in addition to radiographs to determine the correct diagnosis and next steps for treatment. Pain and discomfort can limit the physician’s ability to complete a physical examination in the clinic. Thus, radiographs are essential to making the diagnosis of a tibial eminence fracture. Anteroposterior and lateral films with weight bearing, if possible, should be ordered.2 A perfect lateral film provides the optimal view for evaluation and classification of the tibial avulsion fracture.2 Magnetic resonance imaging is useful to evaluate for associated injuries, such as meniscal tears, and to evaluate remaining ACL fibers. It is important to determine whether there is any involvement of the femoral origin, which would require a reconstruction. Additionally, for patients with traumatic hemarthrosis, magnetic resonance imaging may prove useful for diagnosis of these fractures, especially nondisplaced type I fractures.2
Patient Positioning and Initial Arthroscopic Evaluation
The patient is positioned supine on the operative table. An examination with the patient under anesthesia should be performed to confirm findings consistent with those documented during the patient’s in-clinic examination. The injured extremity is prepared and draped in a sterile fashion. Attention is then turned to the diagnostic arthroscopy, which should include careful evaluation of all cartilage surfaces and soft-tissue structures (e.g., meniscus), in addition to the ACL avulsion fracture (Fig 1). An arthroscopic probe can be used to hinge the fracture fragment to accommodate better visualization of the knee compartments.
| Pearls | Pitfalls |
|---|---|
| The surgeon should ensure that all fibrinous tissue is removed at the fracture site prior to reduction. | Fibrinous debris can block reduction. |
| The surgeon should pass the anteromedial bundle cinch suture from the anteromedial portal and pass the posterolateral bundle cinch suture from the anterolateral portal and then bring both sutures out of the anteromedial portal. | |
| The surgeon should use a probe through the anterior medial portal to pull the intermeniscal ligament anterior while reducing the fragment with the tibial guide through the same portal. | The intermeniscal ligament can block reduction. |
| The surgeon should use a tibial ACL guide to hold the reduction while placing 2.4-mm guide pins. | If the fragment is not reduced during tunnel creation, the sutures will not properly reduce the fragment. |
| Hammering in stepped drill sleeve ensures a smooth transition from removal of the 2.4-mm guide pin and retrieval of suture. | The tunnel vector can be lost between removal of the 2.4-mm guide pin and placement of the SutureLasso needle. |
| The surgeon should hold the reduction with the tibial ACL guide on the anteromedial bundle during removal of the anteromedial 2.4-mm guide pin and passage of the SutureLasso needle. | If the reduction is not held securely with 2 guide pins or the ACL drill guide, the fragment can displace during removal of the guide pins and placement of the SutureLasso needle. |
| The surgeon should retrieve the repair suture and passing limb of the knotless FiberTak through the portal in which the FiberTak was placed to avoid a suture bridge and to optimize smooth activation of the knotless mechanism. | |
| ACL, anterior cruciate ligament. | |
Tibial Avulsion Fracture Reduction Technique
With the diagnostic arthroscopy now complete and no concomitant pathology identified, attention can be turned to the ACL repair and fracture fragment fixation. The first step in the repair involves levering up the fragment and preparing the fracture site using
instruments such as a meniscal rasp and arthroscopic shaver to remove all fibrinous debris (Fig 2). With the bone bed prepared, the fragment can be reduced. This step may require positioning the intermeniscal ligament anteriorly because the ligament can prevent successful reduction of the fragment.
Suture Passage Through Each ACL Bundle
The next step involves suture passage through the ACL. To help with instrumentation and suture management throughout the remainder of the case, a PassPort cannula (Arthrex, Naples, FL) can be inserted through the anteromedial portal. Through the anteromedial portal, a suture with a loop on 1 end (FiberLink [Meniscus Root Repair Implant System]; Arthrex) is passed through the anteromedial bundle with a self-retrieving suture passer, such as a Scorpion (Arthrex) (Fig 3). The free end of the suture is passed through the loop and slack is eliminated to create a cinch suture pass. Through the anterolateral portal, a second suture with a loop on 1 end (TigerLink [Meniscus Root Repair Implant System]; Arthrex) is passed through the posterolateral bundle with a self-retrieving suture passer. The free end of the suture is passed through the loop and slack is eliminated to create a cinch suture pass. Both sutures are then retrieved through the medial portal.
Fig 1. Arthroscopic view of anterior cruciate ligament from anterolateral portal (right knee). During the diagnostic arthroscopy, it is important to evaluate for concomitant pathology. This includes evaluating the femoral origin (blue arrow) of the anterior cruciate ligament to ensure that it is intact. The diagnostic arthroscopy should also include careful evaluation of the medial and lateral menisci.
Fig 2. Arthroscopic view of injured anterior cruciate ligament (ACL) from anteromedial portal (right knee). After completion of the diagnostic arthroscopy including confirmation of the intact femoral origin of the ACL, attention is turned to freeing the fracture fragment and debriding the fibrinous tissue (blue arrow) that has formed on the tibia at the site of the avulsion. The combination of a rasp (black arrow) and torpedo shaver can be used to create a bleeding healthy bone bed that will promote fracture healing. The intermeniscal ligament may limit visibility or preparation of the avulsion site. If this occurs, the intermeniscal ligament can be moved anteriorly to facilitate debridement and anatomic reduction of the tibial origin of the ACL.
Fragment Reduction and Drilling of Reduction Tunnels
A point-to-point tibial ACL guide (Pin Tip Tibial Marking Hook; Arthrex) is used to reduce and hold the fragment. If the intermeniscal ligament is blocking reduction, the surgeon can use a probe through the anteromedial portal to pull the intermeniscal ligament anterior while reducing the fragment with the tibial guide through the same portal. An incision is made over the anteromedial tibia and the periosteum is elevated where the guide meets the tibia for drilling a tibial tunnel. Two 2.4-mm tunnels are then serially drilled using the tibial ACL guide and two 2.4-mm guide pins: one for the anteromedial bundle and one for the posterolateral bundle. The anteromedial drill tunnel is drilled first, and the 2.4-mm guide pin is left in place to hold the reduction. The tibial guide is repositioned for the posterolateral bundle tunnel, the reduction is held, and a second 2.4-mm guide pin is drilled and left in place. A stepped drill sleeve with a 2.4-mm guide pin sleeve (FlipCutter Drill System; Arthrex) is placed over the posterolateral-bundle 2.4-mm guide pin and hammered into the tibia to secure the tunnel vector. The guide pin is removed, and a SutureLasso needle with nitinol passing wire (Meniscus Root Repair Implant System; Arthrex) is shuttled up the tunnel and used to retrieve the posterolateral-bundle repair suture. The stepped drill sleeve with the 2.4-mm guide pin sleeve is removed from the tibia and repositioned as described earlier over the 2.4-mm guide pin already placed for the anteromedial bundle. The guide pin is removed, and a SutureLasso needle with nitinol passing wire is shuttled up the tunnel and used to retrieve the anteromedial-bundle repair suture. By use of these sutures, the fragment is re-reduced and the reduction is held by eliminating all slack from the reduction sutures. On the anteromedial tibia 1 to 2 cm distal to the guide pin holes, a drill hole is made and then tapped for insertion of a 4.75-mm SwiveLock suture anchor (Meniscus Root Repair Implant System; Arthrex). The repair sutures are loaded onto the SwiveLock suture anchor, suture slack is again eliminated by tensioning the sutures, and the SwiveLock is secured on the anteromedial tibia. This completes and holds the fracture fragment reduction.
Compression of Reduction
Next, a double-pulley compression construct is made over the reduced fragment with two 1.8-mm knotless FiberTak soft anchors (Arthrex). One anchor is placed medial to the reduced fragment, and one anchor is placed lateral to the reduced fragment. This requires 1 or 2 additional percutaneous portals (superomedial and/or superolateral), at times through the patellar tendon. A spinal needle is used to plan portal placement and optimize the vector for anchor placement. Knee flexion and a curved drill and/or insertion guide can also facilitate placement of these anchors (Fig 4). After placement of both anchors, the repair suture from one anchor is activated through the knotless mechanism of the other anchor. This step is repeated with the second
anchor’s repair suture (Fig 5). This creates a double-pulley mattress compression system; the repair sutures are tensioned and sequentially retensioned until adequate compression is obtained at the repair site (Fig 6). Each anchor should be tensioned through the portal in which it was placed. An arthroscopic probe can be used to confirm a stout repair construct after reduction and compression.
Fig 3. Arthroscopic views of anterior cruciate ligament from anterolateral portal (left knee). (A) A Scorpion suture passer is used to facilitate passage of sutures through both bundles of the anterior cruciate ligament. A suture passed through the anterior medial bundle (blue arrow) is shown. (B) By use of a point-to-point guide (Arthrex), the transosseous tunnels through which the sutures will be passed can be drilled with a 2.4-mm drill. The previously passed sutures (blue arrows) are then pulled through the transosseous tibial tunnels via a drill sleeve (black arrow) and secured to the anteromedial tibia with a SwiveLock anchor. Tension should be applied to these sutures to visibly reduce the fracture fragment to the tibia. With this anchor secured, the first half of the repair is now complete.
Rehabilitation
Ten degrees of terminal extension is blocked for the first 4 weeks. An adjustable, hinged knee brace is used to restrict motion during this time. For the first 2 weeks, the brace is allowed −10° to 50° of motion, blocking the last 10° of extension. For the second 2 weeks, the brace is allowed −10° to 90° of motion, blocking the last 10° of extension. All range-of-motion restrictions are lifted at the 4-week milestone. The patient is kept toe-touch weight bearing for the first 6 weeks and then follows a 1-week crutch-weaning protocol.
Discussion
Operative techniques to reduce tibial avulsion fracture after ACL injury have continued to focus on screw and suture fixation methods. Callanan et al.7 compared suture fixation versus screw fixation in 68 knees in 67 patients who underwent surgical repair for type II or III tibial spine avulsion fractures. They found a significant difference in the reoperation rate between the 2 groups with an increased odds of reoperation for the screw fixation group. Recently introduced arthroscopic techniques to reduce tibial avulsion fractures have included a transosseous suture-bridge fixation technique, as well as a suture lever reduction technique.8,9 Both techniques incorporate anchors into the suture constructs.
The tensionable suture anchor construct allows for tensionable and retensionable compression of the reduced fracture fragment. Similar suture anchor constructs have been described recently for other procedures including arthroscopic remplissage and fixation of osteochondritis dissecans lesions.10-12 The hypothesized advantages of the technique compared with screw fixation techniques are that, in our experience, there is a lower planned reoperation rate to remove hardware and less disruption of the anatomic ACL footprint. The hypothesized advantage of the construct when compared with suture fixation techniques is that the knotless anchor construct reduces the risk of knot failure. The combined reduction and compression forces generated by this construct theoretically provide a higher mean ultimate failure load.6 One limitation of the technique is that the patient’s native patellar alignment, specifically patella baja, may affect FiberTak anchor placement. In conclusion, this technique achieves anatomic reduction and compression of avulsed tibial avulsion fragments, both important anatomic principles in orthopaedic fracture fixation.
Fig 5. Arthroscopic view of anterior cruciate ligament from anteromedial portal (right knee). After FiberTak placement, the suture limbs are passed to the opposite anchor with the passing suture (blue arrows). This step is performed for each anchor.
References
- Beck NA, Lawrence JTR, Nordin JD, DeFor TA, Tompkins M. ACL tears in school-aged children and adolescents over 20 years. Pediatrics 2017;139:e20161877.
- Mall NA, Paletta GA. Pediatric ACL injuries: Evaluation and management. Curr Rev Musculoskelet Med 2013;6:132-140.
- Mann MA, Desy NM, Martineau PA. A new procedure for tibial spine avulsion fracture fixation. Knee Surg Sports Traumatol Arthrosc 2012;20:2395-2398.
- Meyers MH, McKeever FM. Fracture of the intercondylar eminence of the tibia. J Bone Joint Surg Am 1959;41:209-222.
- Chang CJ, Huang TC, Hoshino Y, et al. Functional outcomes and subsequent surgical procedures after arthroscopic suture versus screw fixation for ACL tibial avulsion fractures: A systematic review and meta-analysis. Orthop J Sports Med 2022;10:23259671221085945.
- Sawyer GA, Anderson BC, Paller D, Schiller J, Eberson CP, Hulstyn M. Biomechanical analysis of suture bridge fixation for tibial eminence fractures. Arthroscopy 2012;28:1533-1539.
- Callanan M, Allen J, Flutie B, et al. Suture versus screw fixation of tibial spine fractures in children and adolescents: A comparative study. Orthop J Sports Med 2019;7:2325967119881961.
- Mutchamee S, Ganokroj P. Arthroscopic transosseous suture-bridge fixation for anterior cruciate ligament tibial avulsion fractures. Arthrosc Tech 2020;9:e1607-e1611.
- Gamboa JT, Durrant BA, Pathare NP, Shin EC, Chen JL. Arthroscopic reduction of tibial spine avulsion: Suture lever reduction technique. Arthrosc Tech 2017;6:e121-e126.
- Callegari JJ, Phillips CJ, Denard PJ. All-inside knotless remplissage technique. Arthrosc Tech 2021;10:e1479-e1484.
- McQuivey KS, Brinkman JC, Tummala SV, Shaha JS, Tokish JM. Arthroscopic remplissage using knotless, all-suture anchors. Arthrosc Tech 2022;11:e615-e621.
- Hsu JC, Tran DH. Arthroscopic fixation of knee osteochondritis dissecans with interlinked knotless all-suture anchors. Arthrosc Tech 2022;11:e1013-e1019.
For additional information on ACL knee injuries, or to learn more about what is involved during ACL reconstruction surgery, please contact the office of orthopedic knee surgeon, Dr. Adam Anz, serving the greater Pensacola, Gulf Breeze, and Gulf Coast communities.
