950 DISPLACEMENT OF THE BICEPS FEMORIS MUSCLE. 



VIII. DISPLACEMENT OF THE BICEPS FEMORIS MUSCLE. 



In cattle the biceps femoris or long vastus muscle glides on the 

 greal trochanter of the femur by means of a large serous bursa, and 

 its anterior border is firmly embraced by the double laminse of the 

 fascia lata. From varying causes this fascia may become fissured, 

 or unduly stretched, and in consequence the muscle slips backwards 

 off the trochanter, which passes into the fissure, and flexion of the 

 femur is impossible. 



The accident happens particularly in emaciated animals with 

 prominent trochanters and in mountain cattle with sloping quarters, 

 and is caused by slipping with the limb extended backwards, in the 

 row shed, at work, or in coitus. 



Symptoms. The lameness is usually confined to one leg. 

 Immediately the muscle becomes fixed behind the trochanter, flexion 

 of the thigh is impossible and lameness is at once developed. The 

 limb is fixed in an extended position similar to that in upward luxation 

 of the patella, or is thrust outwards and forwards with a kind of 

 " mowing " movement, the claws scraping the ground. On local 

 examination, the trochanter appears very prominent and situated 

 directly above a rigid cord which extends parallel with the anterior 

 margin of the luxated muscle. Winkler denies having seen the 

 mowing movement in the twenty cases which came under his notice, 

 but draws attention to the similarity between this lameness and 

 luxation of the patella, from which it is only distinguished by the 

 fact that the limb is not so firmly fixed when in the extended position. 

 Sometimes the dislocation is only momentary, the muscle immediately 

 returning to its normal position, so that the animal goes sound for 

 a few steps, but soon after falls lame again. When the muscle becomes 

 fixed in the abnormal position it appears tense, and its outline more 

 distinct, whilst a depression appears in front of the trochanter. 



Course and prognosis. Spontaneous recovery is never permanent ; 

 and unless operation be resorted to, habitual luxation results, i.e., 

 t he lameness continually recurs, or becomes lasting. Prognosis is 

 only grave in working animals. The accident is now less common 

 than formerly, probably because cattle are better fed and better 

 managed. 



Treatment, When the displacement is due to stretching of 

 the fascia, rest and good feeding favour the deposition of fat, and 

 soon alter the conditions responsible for the accident. Counter- 

 irritation may be employed with advantage in cases where spontaneous 

 reduction occurs. If, however, the fascia lata is ruptured and the 



