THE LOWER LIMB 



533 



The posterior or internal crucial ligament is attached inferiorly 

 to the back part of the rough depression on the head of the tibia 

 behind the spine, and to the pophteal notch. Superiorly it is 

 attached to the anterior part of the external surface of the internal 

 condyle of the femur, close to the front part of the intercondylar 

 fossa, upon which it slightly encroaches. Its direction is upwards, 

 forwards, and shghtly inwards. It is stronger, but shorter, than 

 the anterior crucial ligament, and is not so oblique. At its tibial 



Anterior Crucial — 



Ligament 



External Semilunar 



Fibro-cartilage 

 Synovial Membrane — ] 



Long External Laterals 

 Ligament 

 Posterior Superior 

 Tibio-fibular 

 Ligament 



Internal Semilunar 

 Fibro-cartilage 



Synovial Membrane 



Internal Lateral 



Ligament 

 Post. Accessory Bundle 



Posterior Crucial 

 Ligament 



Fig. 253. 



-The Crucial Ligaments of the Left Knee-Joint 

 (Posterior View) (after Spalteholz). 



attachment it is behind the posterior comua of both semilunar 

 5bro-cartilages, the posterior cornu of the internal one being more 

 immediately in front of it and to its inner side. 

 j The posterior crucial ligament is tense in flexion of the knee- 

 ijoint, and checks over-flexion. It is at one period the external 

 llateral ligament of the internal femoro-tibial joint. 



i Two views may be stated as to the origin of the crucial ligaments, 

 i) According to Keith, they are originally parts of the capsule of the knee- 

 toitit, but have become separated from that structure tis the result of the 



