5?6 APPLIED ANATOMY. 



thickness of the foot may be traversed by this means and a drainage-tube passed 

 through from one side to the other. 



Incisions should not be made over bony points where they would be subjected 

 to pressure. Hence the heads of the metatarsal bones and the prominent outer edge 

 of the foot are avoided. Incisions in the hollow of the foot and between the forward 

 ends of the metatarsal bones are to be preferred. In opening a subcutaneous col- 

 lection one should not be satisfied with simply incising the skin, but the fascia should 

 be widely split to guard against a larger collection of pus beneath. 



Collections which present to the outer side of the flexor brevis are to be opened 

 a little distance behind the base of the fifth metatarsal bone because the external 

 plantar artery becomes somewhat superficial at its inner side. 



DEFORMITIES OF THE FOOT. 



The common deformities of the foot are those in which the parts affected are 

 deformed or turned to an abnormal degree in the direction of their normal move- 

 ments. Thus in talipes varus the foot is turned inward, hyperadducted; talipes 

 valgus and flat-foot, turned out, hyperabducted ; talipes equinus or hyperextended, 

 talipes calcaneus or hyperflexed, and talipes cavus or increase of the arch of the foot. 

 These deformities may be either congenital or acquired, and it is not always 

 easy to separate the two. A deformity may be thought by the parents to have 

 existed from birth, when it may have been caused by an infantile paralysis occurring 

 before the period of walking. 



Foot deformities likewise possess two characteristics which are marked, they 

 are those of paralysis or weakness and contraction or strength. They are usually 



associated but sometimes separate. 

 There can be a paralysis without con- 

 traction, but inasmuch as the mus- 

 cular system is built on the principle 

 of balance it is obvious that if one 

 muscle or set of muscles is paralyzed 

 it is only a question of time until the 

 opposing muscles become contracted. 

 In a similar manner if contraction 

 exists as the most prominent element 

 and perhaps the primary one, it will 

 usually be found that the opposing 

 muscles and ligaments are stretched 

 and weakened. 



These conditions furnish the indi- 

 cations for treatment. Where weak- 

 ness is the predominant feature then 

 FIG. 595. Talipes equinovarus. support is to be given and contraction 



of the relaxed tissue favored. Where 



strength and contraction is predominant then operations and forcible measures are 

 necessary to overcome them. Also, when in a contracted case the contracted tissues 

 have been overcome, there still remains the weakness of the opposing tissues to be 

 remedied. It may be possible to bring the foot to a perfectly normal position, but 

 until the previously weakened and overstretched tissues have regained their tone 

 normal function will not be possible. 



While the deformities may be simple they are usually compound ; thus an 

 equinus may be associated with a varus or valgus, and is then called an equino- 

 varus or equinovalgus. Cavus or hollow-foot and calcaneous or lowering of the heel 

 are often associated, so that it is difficult to draw a line separating them. 



Talipes Varus. Talipes varus in its most common form is congenital and is 

 often associated with equinus or a drawing up of the heel. The prevailing deformity 

 is one of adduction, with a certain amount of inward rotation (Fig. 595). The mus- 

 cles favoring it are the tibialis anterior and tibialis posterior ; therefore the tendons 

 of these muscles are sometimes cut to prevent their drawing the foot upward and 



