THE BONY PELVIS. 



497 



raising the <7^ducted limb, but doing so will increase their inequality still more and shift 

 the pelvis too far to the left. For this reason raising the shoe is not advisable, but an 

 osteotomy and removal of the adduction or abduction is the proper treatment. 



Effects of Shortening or Lengthening of a Lower Extremity. The 

 shortening of one limb produces the same effect as the lengthening of the opposite one: 

 in other words it is the inequality of the limbs that counts. In Fig. 497, D the right 

 extremity is the shorter; this causes the pelvis to tilt to the right, carrying the lower 

 part of the spine with it and producing a right convex curve which is most marked 

 in the lumbar region. To restore the equilibrium the parts above are carried to the 

 left. Thus a lateral curvature is produced, which, contrary to those which originate 

 in the spine, is accompanied by tilting of the pelvis. In these cases the deformity 

 may be great. If the spinal curvature extends high the shoulders may be uneven, 

 the hips are uneven in height and one projects farther out than the other, the legs 

 may be visibly unequal in length, and there is marked limping of gait. The remedy 

 is obvious. The short limb is to be made equal to the long one by raising the shoe 

 or by other means. 



MEASUREMENT OF THE LOWER LIMBS. 



The ability to determine accurately the length of the lower extremities is essen- 

 tial to diagnosis and important in treatment. It is a difficult thing to do and requires 

 knowledge, care, and practice. It may be accepted as a fact that the limbs are nor- 



FIG. 498. Measurements of the lower limbs, viewed from the front, a, left anterior superior spine; b, right 

 anterior superior spine; c, left trochanter; d, right trochanter; e, left internal malleplus; /, right internal malleolus; 

 g, umbilicus; h, lower end of median line. 



Fig. A. The line of the pelvis a-b is in its correct position at a right angle to the long axis of the body g-h; 

 a-e equals b-f, and g-e equals g-f and a-c equals b-d. 



Fig. B. The limbs in this figure are of equal length but the pelvis is tilted. The pelvis a-b is tilted up on 

 the left and down on the right. Apparent shortening of the left leg is seen by comparing g-e with g-f. Actual measure- 

 ment shows a-e to be a trifle longer than b-f and a-c longer than b-d. 



Fig. C. One leg shorter than the other, but the pelvis is in the correct position. The actual shortening 

 found by comparing a-e with b-f corresponds with the apparent shortening found by comparing g-e with g-f. 



Fig. D. Legs unequal, pelvis tilted down on the side of the short leg. The apparent lengths g-e and g-f, 

 taken from the umbilicus g, show the legs apparently equal, but the distance b-f is longer than a-e and the absolute 

 or actual amount of shortening is only to be found by levelling the pelvis as in Fig. C, when the apparent and actual 

 amount of shortening will be found to agree. 



mally equal in length. It is true that in rare cases there may be a slight inequality, 

 but an amount of inequality readily detected by measurement will usually produce 

 an unevenness in the gait, a slight limp. 



To measure accurately, bony landmarks are preferable to the soft parts, such as 

 the umbilicus; these bony points must be carefully identified, they must be in their 

 normal position, and the tape-measure must be accurately applied. 



Measurements are usually taken either from the umbilicus or anterior superior 

 spines to the internal malleoli. The latter is the more accurate and shows the actual 



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