Authors:
Diego Sánchez Cruz . MD*,
Orthopedist, Orthopedics and Traumatology Center. Bogota, Colombia
Ricardo Castro Gaona. MD,
Orthopedist, Orthopedics and Traumatology Center. Bogota, Colombia
Néstor Sánchez Dicelis. MD,
Orthopedist, Orthopedics and Traumatology Center. Bogota, Colombia
Gabriel Larrota. MD,
Orthopedist, Orthopedics and Traumatology Center. Bogota, Colombia
*email: diegosancruz@hotmail.com
All the authors declare no conflict of interest.
INTRODUCTION
Although the anatomy and function of the lateral meniscus has been very well described, its capsular restrictors and their role in meniscus function remain complex. The structures of the popliteal hiatus are stabilizers of the lateral meniscus; therefore, their integrity is necessary to preserve adequate kinematic behavior of the lateral compartment.
Injuries to these structures can go unnoticed, therefore, knowing the arthroscopic anatomy and developing a systematic evaluation sequence is important to not overlook possible compromises of these structures.
AIM
The objective of the video is: To articulate the anatomical descriptions of the capsular restrictors of the Lateral Meniscus with arthroscopic findings, to expose a diagnostic routine during knee arthroscopy so as not to overlook possible compromises of these structures.
THECNIQUE DESCRIPTION
Description of the arthroscopic points and the anatomy of the capsular restrictors.
We could, for the purposes of compression and learning, divide the structures into two large groups, those that are proximal to the superior opening of the popliteal hiatus and those that are distal to said opening.
In the first group (proximal) we find the following structures from anterior to posterior:
- Anterior Meniscal Popliteal Fascicle
- Posterosuperior Meniscal Popliteal Fascicle
- Posterior synovial meniscus insertions
In the second group (distal) we find the following structures from anterior to later:
- Lateral Tibial Meniscus Ligament
- Fibular Meniscus Fascicle
- Posteroinferior Popliteal Fascicle
- Posterior Tibial Meniscus Ligament
- Fibular Popliteal Ligament
And although the posterior root of the lateral meniscus does not correspond to the capsular restrictors of the meniscus, given its clinical importance, it is included in the arthroscopic diagnostic routine.
Description
- Posterior Tibial Meniscus Ligament: A small posterolateral restrictor connects the inferior margin of the posterior horn of the meniscus to the tibia. The average length of the posterior tibial meniscus ligament is 12.8 mm, it is thought to contribute to the stability of the posterior horn of the lateral meniscus, although we lack biomechanical data on this ligament. To be able to see it clearly, it is suggested to turn the optic 90º medially and move the lens slightly laterally, while pulling the posterior horn of the meniscus cephalad with a tester.
- Posterior Root of the Lateral Meniscus: And in this same position, although we understand that the RPML does not obey a capsular restrictor, it is a structure of utmost importance, which is involved in the diagnostic routine and that, with the position of the arthroscope for the clear identification of the Tibial Meniscus Ligament, its insertion imprint is exposed with frank clarity.
- Posteroinferior Meniscal Popliteal Fascicle: The MPF-PI is considered to be the most difficult MPF to isolate. The FPM-PI is the structure that connects the inferior margin of the lateral meniscus with the medial portion of the popliteus muscle. The average length of the insertion of the fascicle to the lateral meniscus is 8.5 ± 1.8 mm.
- Fibular Meniscus Fascicle: The FMF is a thin fibrous band that originates on the inferior meniscal surface, inferior and posterior to the FPM-A. The direction of the Fibular Meniscus Fascicle is distal and posterior, towards the tip of the fibula, with an oblique course that crosses the route of the popliteus tendon; can be seen as a distinct structure, between the LMTL anteriorly and a hole marking the posterior crus of the Fibular Meniscus Fascicle and the anterior crus of the posteroinferior meniscal Popliteal Fasciculus.
- Posterosuperior Popliteomeniscal Fascicle: Originates on the posterior surface of the popliteus tendon and ends at the top of the posterior horn of the meniscus. The average length of its insertion into the lateral meniscus is 6.5 ± 1.5 mm.
- Anterior Popliteomeniscal Fascicle: The anterior meniscal popliteal fasciculus originates in the inferomedial portion of the popliteus tendon and inserts into the external surface of the lateral meniscus near its equator, delimiting the anterior margin of the superior opening of the popliteal hiatus. It has an average length of 8.0 ± 1.9 mm.
- Popliteal Hiatus: In the popliteal hiatus, seen from the optic in the lateral recess, the following structures are seen: Posterosuperior meniscal popliteal fasciculus, anterior Popliteomeniscal fasciculus and the fibular meniscus ligament.
- Posterior synovial meniscus insertions: recently some authors have described a lesion similar to the ramp, which is believed to be due to a disinsertion or detachment of a capsule-synovial flap at the level of the posterior horn of the lateral meniscus, which leads to destabilization and possible exposure. of the femoral meniscus ligaments. In this view, it can be seen that in a physiological state, the femoral meniscus ligaments are covered by this tissue flap, which stabilizes them and adheres the posterior horn.
- Lateral Tibial Meniscus Ligament: Corresponds to a short band of ligament that attaches peripherally to the body of the meniscus and serves to stabilize and maintain the meniscus in the proper position on the tibial plateau. These tibial meniscus inserts can help keep the 2 lateral menisci in place and therefore prevent extrusion. Recently, in the journal Arthroscopy, in a cadaveric study, it was documented that the main stability of the posterior third of the lateral meniscus is given by the peripheral insertion of the tibial meniscus ligaments and that its injury is believed to be the origin of the hypomobile meniscus.
NOTE: The fibular popliteal ligament is not included in the diagnostic routine as it cannot be identified arthroscopically, but it is mentioned that the: Anterior Popliteomeniscal Fascicle, the Popliteal-Fibular Ligament and the Lateral Tibial Meniscus Ligament form a common unit called the meniscus-tibio-popliteal fibular complex.
CONCLUSIONS
- It is possible to make an arthroscopic identification of the capsular restrictors of the lateral meniscus.
- Through a systematic evaluation of these 9 arthroscopic points, it is feasible to evaluate the status of these structures to carry out an active search for potential injuries.
REFERENCES
- Masferrer-Pino A, Saenz-Navarro I, Rojas G, Perelli S, Erquicia J, Gelber PE, Monllau JC. The Menisco-Tibio-Popliteus-Fibular Complex: Anatomic Description of the Structures That Could Avoid Lateral Meniscal Extrusion. Arthroscopy. 2020 Jul;36(7):1917-1925. doi: 10.1016/j.arthro.2020.03.010. Epub 2020 Mar 19. PMID:32200063.
- Perelli S, Morales Avalos R, Masferrer-Pino A, Monllau JC. Anatomy of lateral meniscus. Ann Jt. 2022 Apr 15;7:16. doi: 10.21037/aoj-20-118. PMID: 38529162; PMCID: PMC10929306.
- Grassi A, Pizza N, Andrea Lucidi G, Macchiarola L, Mosca M, Zaffagnini S. Anatomy magnetic resonance and arthroscopy of the popliteal hiatus of the knee: normal aspect and pathological conditions. EFORT Open Rev. 2021 Jan 4;6(1):61-74. doi: 10.1302/2058-5241.6.200089. PMID: 33532087; PMCID: PMC7845568.
- Gil Noriega GA, Llinás Hernández PJ, Herrera Huependo GA, Sanchez Cruz DA. Ramp-like lateral meniscus tear. Description of an infrequent lesion. J ISAKOS. 2024 Apr 16:S2059-7754(24)00076-2. doi: 10.1016/j.jisako.2024.04.005. Epub ahead of print. PMID: 38636903.
- Ramos Guarderas, P.A., Rivarola Etcheto, H., Arteaga Guerrero, G.F., Vargas Morante, M.J., Ramos Murillo, P.D., Ramos Murillo, D.A., Peñaherrera Carrillo, C.P. y Endara Urresta, F. 2024. Hipermovilidad del tercio posterior del menisco lateral secundario a lesión de los ligamentos meniscotibiales. Estudio cadavérico. Revista Artroscopia. 31, 01 (abr. 2024).
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