Every foot has a story.
This is not your typical “in this person has internal tibial torsion, yada yada yada” post. This post poses a question and the question is “Why does this gentleman have a forefoot adductus?”
The first two pictures show me fully internally rotating the patients left leg. You will note that he does not go past zero degrees and he has femoral retroversion. He also has bilateral internal tibial torsion, which is visible in most of the pictures. The next two pictures show me fully internally rotating his right leg, with limited motion, as well and internal tibial torsion, which is worse on this ® side
The large middle picture shows him rest. Note the bilateral external rotation of the legs. This is most likely to create some internal rotation, because thatis a position of comfort for him (ie he is creating some “relief” and internal rotation, by externally rotating the lower extremity)
The next three pictures show his anatomically short left leg. Yes there is a large tibial and small femoral component.
The final picture (from above) shows his forefoot adductus. Note that how, if you were to bisect the calcaneus and draw a line coming forward, the toes fall medial to a line that would normally be between the second and third metatarsal’s. This is more evident on the right side. Note the separation of the big toe from the others, right side greater than left.
Metatarsus adductus deformity is a forefoot which is adducted in the transverse plane with the apex of the deformity at LisFranc’s (tarso-metatarsal) joint. The fifth metatarsal base will be prominent and the lateral border of the foot convex in shape . The medial foot border is concave with a deep vertical skin crease located at the first metatarso cuneiform joint level. The hallux (great toe) may be widely separated from the second digit and the lesser digits will usually be adducted at their bases. ln some cases the abductor hallucis tendon may be palpably taut just proximal to its insertion into the inferomedial aspect of the proximal phalanx (1)
Gait abnormalities seen with this deformity include a decreased progression angle, in toed gait, excessive supination of the feet with low gear push off from the lesser metatarsals.
It is interesting to note that along with forefoot adductus, hip dysplasia and internal tibial torsion are common (2) and this patient has some degree of both.
His forefoot adductus is developmental and due to the lack of range of motion and lack of internal rotation of the lower extremities, due to the femoral retrotorsion and internal tibial torsion. If he didn’t adduct the foot he would have to change weight-bearing over his stance phase extremity to propel himself forward. Try internally rotating your foot and standing on one leg and then externally rotating. See what I mean? With the internal rotation it moves your center of gravity over your hip without nearly as much lateral displacement as would be necessary as with external rotation. Try it again with external rotation of the foot; do you see how you are more likely displace the hip further to that side OR lean to that side rather than shift your hip? So, his adductus is out of necessity.
Interesting case! When you have a person with internal torsion and limited hip internal rotation, with an adducted foot, think of forefoot adductus!
1. Bleck E: Metatarsus adductus: classification and relationship to outcomes of treatment. J Pediatric Orthop 3:2-9,1983.
2. Jacobs J: Metatarsus varus and hip dysplasia. C/inO rth o p 16:203-212, 1960