344 



THE AKTICULATIONS OK JOINTS. 



and slightly concave transversely. This surface is almost circular, and extends 

 to the free lateral border of the tibial condyle, where it is somewhat flattened. 

 Posteriorly the articular surface is prolonged downwards on the condyle in 

 relation to the position occupied by the tendon of the popliteus muscle. The 

 medial condylar facet is oval in outline, and distinctly concave both in its antero- 

 posterior and transverse diameters. 



proximal to the articular cavity, subjacent 

 to the tendon of the quadriceps extensor muscle. Its specially named bands are not 



Tendon of adductor magnus muscle (cut) 



Medial head of gastrocnemius (cut) 



Oblique popliteal ligament 



Bursa beneath tendon of 

 semi-membranosus 



Popliteal surface of femur 



Plantaris muscle (cut) 



Tendon of semi-membranosus 

 muscle (cut) 



Oblique popliteal ligament 

 Tibial collateral ligament 



Lateral head of gastro- 

 cnemius muscle (cut) 



Fibular collateral 

 ligament (long) 



Fibular collateral 

 ligament (short) 



Popliteus muscle (cut) 



Biceps flexor 

 cruris muscle (cut) 



Popliteus fascia 

 Popliteus | muscle (cut) 



Popliteal surface of tibia 



Fm. 318. THE KNEE-JOINT. POSTERIOR VIEW. 



of themselves sufficient to form a complete investment, and the fibrous stratum, 

 which largely consists of augmentations from the fascia lata and the tendons of 

 surrounding muscles, supplies the defective areas. Thus, anteriorly, on each side 

 of the patella and the ligamentum patellae, expansions of the vasti tendons and 

 fascia lata, constituting the collateral patellar ligaments, are evident. On the lateral 

 side of the joint the fibular collateral ligament is hidden within a covering derived 

 from the ilio-tibial tract of the fascia lata. On the medial side expansions from the 

 tendons of the sartorius and semi-membranosus muscles augment the articular 

 capsule, which here becomes continuous with the ligamentum collaterale tibiale. 

 Posteriorly the articular capsule also receives augmentation from the tendon of 

 the semi-membranosus muscle, but it is very thin subjacent to the origins of the 

 gastrocnemius muscle, where it covers the posterior parts of the condyles. Not 

 unfrequently the articular capsule presents an opening of communication between 



