Case Reports

Avulsion of the Anterior Lateral Meniscal Root Secondary to Tibial Eminence Fracture

Publish date: May 8, 2018

References

1. James EW, LaPrade CM, Ellman MB, Wijdicks CA, Engebretsen L, LaPrade RF. Radiographic identification of the anterior and posterior root attachments of the medial and lateral menisci. Am J Sports Med. 2014;42(11):2707-2714. doi:10.1177/0363546514545863.

2. LaPrade CM, Foad A, Smith SD, et al. Biomechanical consequences of a nonanatomic posterior medial meniscal root repair. Am J Sports Med. 2015;43(4):912-920. doi:10.1177/0363546514566191.

3. LaPrade CM, James EW, Cram TR, Feagin JA, Engebretsen L, LaPrade RF. Meniscal root tears: a classification system based on tear morphology. Am J Sports Med. 2015;43(2):363-369. doi:10.1177/0363546514559684.

4. Ellman MB, James EW, LaPrade CM, LaPrade RF. Anterior meniscus root avulsion following intramedullary nailing for a tibial shaft fracture. Knee Surg Sports Traumatol Arthrosc. 2015;23(4):1188-1191. doi:10.1007/s00167-014-2941-5.

5. Padalecki JR, Jansson KS, Smith SD, et al. Biomechanical consequences of a complete radial tear adjacent to the medial meniscus posterior root attachment site: in situ pull-out repair restores derangement of joint mechanics. Am J Sports Med. 2014;42(3):699-707. doi:10.1177/0363546513499314.

6. LaPrade CM, Jisa KA, Cram TR, LaPrade RF. Posterior lateral meniscal root tear due to a malpositioned double-bundle anterior cruciate ligament reconstruction tibial tunnel. Knee Surg Sports Traumatol Arthrosc. 2015;23(12):3670-3673. doi:10.1007/s00167-014-3273-1.

7. Mitchell JJ, Sjostrom R, Mansour AA, et al. Incidence of meniscal injury and chondral pathology in anterior tibial spine fractures of children. J Pediatr Orthop. 2015;35(2):130-135. doi:10.1097/BPO.0000000000000249.

8. Monto RR, Cameron-Donaldson ML. Magnetic resonance imaging in the evaluation of tibial eminence fractures in adults. J Knee Surg. 2006;19(3):187-190.

9. Ishibashi Y, Tsuda E, Sasaki T, Toh S. Magnetic resonance imaging AIDS in detecting concomitant injuries in patients with tibial spine fractures. Clin Orthop Relat Res. 2005;(434):207-212.

10. Bhatia S, LaPrade CM, Ellman MB, LaPrade RF. Meniscal root tears significance, diagnosis, and treatment. Am J Sports Med. 2014;42(12):3016-3030. doi:10.1177/0363546514524162.

11. Ziegler CG, Pietrini SD, Westerhaus BD, et al. Arthroscopically pertinent landmarks for tunnel positioning in single-bundle and double-bundle anterior cruciate ligament reconstructions. Am J Sports Med. 2011;39(4):743-752. doi:10.1177/0363546510387511.

12. Furumatsu T, Kodama Y, Maehara A, et al. The anterior cruciate ligament-lateral meniscus complex: a histological study. Connect Tissue Res. 2016;57(2):91-98. doi:10.3109/03008207.2015.1081899.

13. Lubowitz JH, Grauer JD. Arthroscopic treatment of anterior cruciate ligament avulsion. Clin Orthop Rel Res. 1993;(294):242-246.

14. Falstie-Jensen S, Sondergard Petersen PE. Incarceration of the meniscus in fractures of the intercondylar eminence of the tibia in children. Injury. 1984;15(4):236-238.

15. LaPrade CM, LaPrade MD, Turnbull TL, Wijdicks CA, LaPrade RF. Biomechanical evaluation of the transtibial pull-out technique for posterior medial meniscal root repairs using 1 and 2 transtibial bone tunnels. Am J Sports Med. 2015;43(4):899-904. doi:10.1177/0363546514563278.

16. Menge TJ, Chahla J, Dean CS, Mitchell JJ, Moatshe G, LaPrade RF. Anterior meniscal root repair using a transtibial double-tunnel pullout technique. Arthrosc Tech. 2016;5(3):e679-e684. doi:10.1016/j.eats.2016.02.026.

17. Menge TJ, Dean CS, Chahla J, Mitchell JJ, LaPrade RF. Anterior horn meniscal repair using an outside-in suture technique. Arthrosc Tech. 2016;5(5):e1111-e1116. doi:10.1016/j.eats.2016.06.005.

Postoperatively, the patient was placed on a non-weight-bearing protocol for her operative lower extremity for 6 weeks. A brace locked in extension was used for the same period of time (being removed only for physical therapy exercises). Enoxaparin was used for the first 2 weeks for deep vein thrombosis prophylaxis, followed by aspirin for an additional 4 weeks. Physical therapy was started on postoperative day 1 to begin working on early passive ROM exercises. Knee flexion was limited to 0° to 90° of flexion for the first 2 weeks and then progressed as tolerated.

DISCUSSION

This article describes a rare case of a patient with lateral meniscal anterior root avulsion in the setting of a tibial eminence fracture with subsequent malunion and root displacement. In a case such as this, delineation of the true extent of the injury is difficult because the anterior meniscal root can be torn, displaced, and nonanatomically scarred to surrounding soft tissues, making MRI interpretation challenging. Clinically, patients can present with a wide range of symptoms, including pain, mechanical symptoms, instability, and loss of knee motion.¹⁰

The anterior root of the lateral meniscus has been reported to be attached anterior to the lateral tibial eminence and adjacent to the insertion of the ACL. Fibrous connections extending from the anterior horn of the lateral meniscus attachment to the lateral tibial eminence are constant.¹¹ Furumatsu and colleagues¹² demonstrated the existence of dense fibers linking the anterior root of the lateral meniscus with the lateral aspect of the ACL tibial insertion. Acknowledging the close relationship of these structures is key to comprehending the importance of evaluating the anterior horn of the lateral meniscus in cases of tibial eminence fractures at the initial time of injury. Failure to diagnose this pathology can lead to poor clinical outcomes and early degenerative changes of the knee.

Tibial intercondylar eminence avulsion fractures are most likely to occur in children and adolescents, and are equivalent to an ACL tear in adults.¹³ When tibial eminence fractures occur in an older cohort, they are often combined with lesions of the menisci, capsule, or collateral ligaments.¹⁴The initial injury in our patient demonstrated concomitant anterior root injury that progressed with time to nonanatomical healing of the root, leading to altered biomechanics. Surgical techniques available for meniscal root repair are broadly divided into transosseous suture repairs and suture anchor repairs.¹⁰ The transtibial pullout technique using 2 transtibial bone tunnels as described in this report is the senior author’s (RFL) preference because it provides a strong construct with minimal displacement of the repaired meniscus.^15-17

This article describes a complete avulsion of the anterolateral meniscal root caused by a tibial eminence fracture with resultant malunion and displacement of the root in a nonanatomic position. Anterior meniscal root tears have been reported to result in altered biomechanics and force transmission across the knee, and therefore, anatomic repair of the anterior root is indicated.