Journal of Modern Rehabilitation July 2020, Volume 14, Number 3 Review Paper: Role of the Popliteal Fossa in Knee Problems: Theoretical Considerations and Practical Implications Maghsoud Eivazi Gh1, Amin Alilou2, Sara Fereydounnia3* , James Selfe4, Sahar Zamani5 1. Faculty of General Medicine, Azerbaijan Medical University, Baku, Azerbaijan. 2. Faculty of Dentistry, Azerbaijan Medical University, Baku, Azerbaijan. 3. School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. 4. Department of Allied Health Professions, Faculty of Health, University of Central Lancashire, Preston, England. 5. School of Rehabilitation Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Use your device to scan and read the article online Citation: Eivazi Gh M, Alilou A, Fereydounnia S, Selfe J, Zamani S. Role of the Popliteal Fossa in Knee Problems: Theoretical Considerations and Practical Implications. Journal of Modern Rehabilitation. 2020; 14(3):131-140. http://dx.doi.org/10.32598/ JMR.14.3.4 : http://dx.doi.org/10.32598/JMR.14.3.4 A B S T R A C T Article info: The popliteal fossa is located at the back of the knee joint and it is an area where blood vessels Received: 13 Jan 2020 and nerves and also lymph nodes pass. Popliteal fossa injuries includes nearly 2% of acute knee Accepted: 05 May 2020 injuries. The treatment of chronic injuries are always more difficult than acute ones, because its Available Online: 01 Jul 2020 diagnosis would depend on careful interpretation of specific clinical exams. In this review, we Keywords: describe our current understanding of role of popliteal fossa in knee problems, and summarize the anatomy and functional role of popliteal fossa and popliteomeniscal fibers, and mechanism Posterolateral corner of of popliteomeniscal fibers injuries, and discuss strategies for diagnosis of popliteomeniscal the knee, Popliteus Fossa, fibers lesions, differential diagnosis, and treatment of the posterolateral corner injuries. Popliteomeniscal fascicles, Injury 1. Introduction fossa is covered by the knee joint capsule and the ceiling is covered by superficial fascia and skin [1, 2]. he popliteal fossa is an important area between the thigh and leg which is the The popliteus muscle contains many muscle spindles main area for passing the neurovascu- which are arranged in complex form [3].The most part of lar structures from thigh to leg and vice its kinesthesia is monitoring the locking and unlocking T versa. This fossa is a lozenge shaped of human knee joint [4]. Therefore, it can be concluded space which is located at the posterior that in case of any injury in the ligaments insertion of aspect of the knee joint between the posterior compart- popliteus muscle, the locking and unlocking mechanism ment muscles of thigh and leg. The main contents of is likely to be disturbed. In other words, it may disrupt the popliteal fossa include the popliteal artery, popliteal the overall function of the knee. vein, tibial and common fibular nerves. The floor of the * Corresponding Author: Sara Fereydounnia, PhD. & PT. Address: School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. Tel: +98 (21) 77533939 E-mail: [email protected] 131 Journal of July 2020, Volume 14, Number 3 Modern Rehabilitation Popliteal fossa injuries account for nearly 2% of acute They also have shown the presence of correlation with knee injuries [5]. However damages to the posterolateral the amount of meniscal subluxation and joint space nar- elements of the knee are relatively rare, but are becoming rowing in the medial or lateral part of the knee. The con- progressively diagnosed in isolation or more commonly nection of the meniscus with bony and surrounding soft as a part of combined injuries in this region. Since, the tissues has a complex arrangement and may have a role treatment of chronic injuries are always more difficult in prevention of the meniscal subluxation [15]. Based on than acute [6], but diagnosis and treatment is not so easy the above observations, popliteus muscle hypofunction because it would depend on careful interpretation of spe- or its ligamentous shortness and inactivity may have a cific clinical exam [7-9] which it seems difficult as well role in contributing to meniscal subluxation and knee when posterolateral injuries occur in combined formats. osteoarthritis development. Therefore, we aimed to in- vestigate the role of popliteomeniscal fascicles in devel- Diamntopoulos et al. claimed that clinically undetected oping of the knee problems. posterolateral corner injuries have been responsible for sur- gical failure following ACL or PCL repair/reconstruction or 2. Anatomy and the Functional Role of the chronic knee discomfort after traumatization [10] (Figure 1). Popliteal Fossa and Popliteomeniscal Fibers Brandt states that ligamentous lesions may help promote According to the report of Grood et al., the upper wall the development of osteoarthrosis by the creating insta- of popliteus fossa consists of superior popliteomeniscal bility and joint laxity [11]. Medial and lateral collateral fascicles and its lower wall is made of lower popliteo- ligaments protect the knee joint against valgus and varus meniscal fascicles. The Medial wall is shaped by the stresses respectively [11]. Knee collateral ligament inju- lateral meniscus itself and the lateral wall is completed ries are considered a risk factor for development of osteo- by the popliteus tendon [16]. Popliteomeniscal fibers are arthritis in human subjects [11-14]. Ligamentous laxity in composed of two fascicles which are combined with the associated with hypermobility syndrome was considered lateral meniscus. The first fascicle which make the floor another recognized risk factor in the knee osteoarthritis of popliteus fossa and mostly covered by synovial tis- [11]. According to Gale’s study, meniscal subluxation in sue [17] is connected inferiorly with the middle third of patients with knee osteoarthritis has been reported as sig- the lateral meniscus and ventrally linked to the popliteus nificantly higher than asymptomatic control subjects. tendon. The second fascicle in the upper section is com- bined with posterior horn of lateral meniscus and builds Figure 1. Schematic representation from superior view of top of right tibia 1. Anterior cruciate ligament; 2. Posterior cruciate ligament; 3. Popliteus tendon; 4. Arcuate ligament; 5. Posterior 1/3 lateral capsular ligament; 6. Lateral meniscus; 7. Medial meniscus. Eivazi Gh M, et al. Role of the Popliteal Fossa in Knee Problems. JMR. 2020; 14(3):131-140. 132 Journal of Modern Rehabilitation July 2020, Volume 14, Number 3 Figure 2. The anterio-inferior popliteomeniscal fascicle A-I: Makes the floor of the popliteal hiatus and the posterior-superior popliteomeniscal fascicle; P-S: makes the roof of the popliteal hiatus. Popliteus Tendon (PT) had been cut and reflected to illustrate clearly the role of 2 popliteomeniscal fascicles. LM: Lateral Meniscus; TP: Tibial Plateau; PH: Popliteal Hiatus. Redrawn after Diamantopoulos et al. [10]. the roof of popliteus fossa. It seems that anterior-inferior able peripheral vascular near the popliteus tendon. This popliteomeniscal fascicles are stronger and thicker than part of lateral meniscus gains nutrition via a ventral ped- postero-superior popliteomeniscal fascicles (Figure 2). icle of synovial tissue which is provided through circular According to the report of Suganuma et al., abnormal micro-vascular to the lateral septum of meniscus. This popliteomeniscal fibers increase the risk of locking and area is also feed by the micro vascular branches which recurrent subluxation of the lateral meniscus [17]. are carried by the popliteomeniscal fascicles [22, 23]. These fascicles are composed of three layers: a dense Ullrich et al. and Terry and Laprade have also reported collagen layer, a vascular layer and a capsular or syno- the existence of third popliteomeniscal fascicle in their vial layer. These fascicles are involved in stabilization anatomic studies which is connected to the posterior of lateral meniscus furthermore they help the popliteus horn of the lateral meniscus. This fascicle is called “pos- tendon in retracting the lateral meniscus [21]. terio-inferior popliteomeniscal” [18-20]. Sussmann et al. believed that the fascicle’s task is to provide a vascu- Based on their view, this area of the meniscus is known lar supply to the lateral meniscus in the area which there as the “bare area”. Bare area is limited by two tendons is no capsular connectivity. In addition these researchers of the popliteomeniscal ligament; upper tendon (supero- showed that the structural relationship between the pop- medial) which is connected to the upper edge of lateral liteus tendon and lateral meniscus can help in stabiliza- meniscus and the lower tendon (infero-lateral) which tion of the area [21]. is joined to the popliteofibular ligament, posterior horn of meniscus and coronary ligament [22, 23]. Jae-hynk According to the report of Arnoczky and Warren the posterolateral part of the lateral meniscus has no perme- Eivazi Gh M, et al. Role of the Popliteal Fossa in Knee Problems. JMR. 2020; 14(3):131-140. 133 Journal of July 2020, Volume 14, Number 3 Modern Rehabilitation Yang et al. reported that the bare part of the lateral me- 3. Mechanism of Popliteomeniscal Fibers Injuries niscus in their study samples was more than 1.5 cm[24] . Most likely a combination of the hyper-extension and Simonian et al. illustrated that the functions of popliteo- varus force exertion is involved in damage of the pos- meniscal ligaments are as the stabilizer of the lateral me- terolateral structures of the knee. Other mechanism is niscus and in the case of ligament rupture, the mobility of simultaneously exertion of force in the direction of tibial the lateral meniscus would increase. They suggested that external rotation and hyperextension [31]. disturbances in the amount of mobility of the lateral me- niscus with hypofunction, adherence and shortness of the Posterolateral injuries can occur in isolation but they ligaments could lead to a disorder in function of the knee.