The synovial folds of the knee joint: Anatomical study

Abstract

Summary. Three in number, the plicae are inconstant synovial structures found within the cavity of the knee joint, and have been recognised for some time. The inferior plica in particular was described by Vesalius in 1555. Both the inferior and medial plicae are vestiges of an intermediate articular disc similar to the menisci. The superior plica derives from the wall which in the first instance, separates the bursa and quadriceps cul-de-sac.One knee joint out of four retains the medial plica. We have divided it into two types according to its size. 6% of knee joints have a large plica (type II) which according to our observations is the type most likely to become clinically symptomatic. Rather more than one knee out of two has a superior plica: we have identified three types according to the completeness of the split in the wall dividing bursa from quadriceps cul-de-sac. Two knee joints out of three have an inferior plica; here again we have identified three types according to the degreee of extension of the plica antero-posteriorly. We thought it of practical usefulness to describe the radiographic anatomy of each plica.It seemed particularly worthwhile to restructure the anatomical findings, based on 200 dissections, in the more general context of clinical anatomy. Les plicae. Etude anatomique portant sur la dissection de 200 genouxR6sum& Au nombre de trois, les plicae sont des formations synoviales inconstantes de la cavit6 articulaire du genou qui sont connues depuis longtemps. C'est notamment le cas de la plica inf6rieure d6crite par V6salius en 1555. Plica inf6rieure et plica m6diale sont toutes deux des vestiges du disque interm6diaire ~t l'exemple des mbnisques. La plica Sup6rieure d6rive de la cloison qui s6pare initialement bourse et cul-desac sous-quadricipitaux.Un genou sur quatre pr6sente la plica m6diale. Nous en avons isol6 deux types en fonction de sa largeur. 6% des genoux pr6sentent une plica large de type lI qui d'apr6s nos constatations seraient celles qui pourraient devenir symptomatiques. Un peu plus d'un genou sur deux pr6sentent la plica sup6rieure. Nous en avons isol6 trois types calqu6s sur la d6his-cence plus ou moins compl6te de la cloison initiale. Deux genoux sur trois pr6sentent la plica inf6rieure. Nous en avons aussi isol6 trois types suivant l'btendue ant6ro-post6rieure de la plica. Pour chaque plica, nous avons jug6 utile de dbcrire son anatomie radiographique.I1 parait utile de reclasser cette 6tude anatomique, portant sur 200 dissections, dans le cadre plus vaste anatomo-clinique.

Plicae: Where Do They Come from and When Are They Relevant?

“…It has the advantage of using magnification with currents of water during the procedure to better identify the plica that may otherwise be unrecognized if it is collapsed or plastered to the wall of the joint. 2…”

“…2). 2,13 Although the mediopatellar plica is the most frequently offending plica in the knee, it lies third in terms of incidence after the infrapatellar and suprapatellar plicae. It is found in 72% of knee arthroscopies.…”

MR and CT Arthrography of the Knee

“…The most frequently seen plica is the infrapatellar plica (ligamentum mucosum), followed by the suprapatellar plica and medial patellar plica. 40,41 The lateral plica is very rare. 42 If present, the plicae can be well seen on T1 fat-saturated arthrographic images secondary to distension of the joint and the presence of intra-articular gadolinium outlining the joint surfaces.…”

Loss of a condyle of the femur or tibia following septic arthritis in infancy: Problems of management and testing of a hypothesis of pathogenesis

“…They estimate that, by the tenth week of intra-uterine development, the knee joint consists of a single cavity [7]. However, several studies have also demonstrated the presence of synovial folds or plicae in foetuses, children and adults that are considered to be remnants of septae separating the compartments of the developing joint [8][9][10][11][12][13][14][15][16][17][18].…”