Although few think about it, I spend considerable time contemplating the wonders of human anatomy, specifically musculo-skeletal architecture. Granted, this is not likely the topic of the musings of your average citizen. Each and every step requires all manner of changes in function and position.

The foot, ankle and lower leg unit is a marvelous piece of biological engineering, that functions beautifully, supporting the human body and propelling us forward at our desired pace. But human variation entails a great many foot types, since people do vary so much.

The foot is a structure that performs many mechanical functions during the course of the average day, and thus, most variations from the norm will eventually produce symptoms.

What about when about when things don’t “line up” correctly, such as in a skew foot deformity? I know, at this point you are likely thinking “What the heck is that?” Really, trust me on this one: it is an interesting condition that is seen with some regularity. Most importantly to our discussion, it has a significant effect on foot mechanics, and therefore on the development of pain.

A skew foot, also known as a ‘Z’ foot, is a condition which stems from a malalignment of the metatarsal bones, in which these bones become slanted inward during the development of a fetus. This architectural condition is known as metatarsus adductus, since the latter term means slanted inward. This is often the reason a child is born “pigeon-toed.”

Many infants born with this type of alignment will spontaneously resolve on their own, but not all do. When left untreated, those that do not will become fixed in this position. Non-operative treatment is possible only very early on, and usually consists of serial casting (the regular and repeated application of a cast, gradually forcing over the affected part of the foot) or passive manipulation, in which the doctor or parent will manually stretch the joints at the base of the forefoot into a better position.

Sometimes the deformity is so severe that surgery may be recommended, but any treatment is obviously dependent on recognition of the presence of this problem by the parents, as well as the pediatrician.

What makes the decision to treat so tricky is the fact that, as mentioned, many do resolve without treatment. Yet, since non-operative treatment really has no significant complications, it’s often recommended not to risk simply watching, and treat regardless.

Treatments differ greatly when evaluating metatarsus adductus in adults versus children. Considering surgical treatment in a child means the deformity is fairly severe, and seems fixed and rigid, not easily reducible.

When metatarsus adductus does not resolve on its own, and no treatment is attempted, the individual affected will ambulate abnormally, in a pigeon-toed fashion. The human body does not like walking with the foot pointed inward. This causes excessive stress to various joints and structures. Compensation will occur, typically in the form of abnormal pronation. Regular readers should know well some of the hazards of this motion of the foot, in which the arch rolls down and in.

Pronation occurs normally during gait, but too much of anything is a bad thing. The excessive pronation that occurs with metatarsus adductus causes the foot to assume a ‘Z’ shape, which explains the alternative name for this deformity.

Some of the hazards alluded to previously? Various deformities of the forefoot, such as hammertoes, can develop. Chronic heel pain also occurs regularly. Chronic pain on the outside of the foot is also common. Tendonitis, bone spurs, even corns, can develop.

Bunions are especially frequent, but what complicates things is that one can have what looks to be a severe bunion deformity, and yet there will be minimal separation between the first and second metatarsals. This is because all of the metatarsal bones are tilted inward, just like the first. Surgical correction of the bunion, with the concurrent presence of an adducted forefoot, is more complex, especially when the sufferer has no idea they are afflicted with this abnormal foot type.

A physician trained in deformities of the foot will recognize this condition, and discuss options. Conservative care is appropriate and beneficial, but when surgery is contemplated, usually it is the consequences of the primary deformity that are corrected, not the adducted metatarsals (the actual root of the problem).

If you have suffered from some chronic lower extremity musculo-skeletal condition, maybe the root of all your pain and problems is this mysterious condition? Only your lower extremity specialist knows for sure!

Editor’s note: Dr. Conway McLean is a podiatric physician now practicing foot and ankle medicine in the Upper Peninsula, having assumed the practice of Dr. Ken Tabor. McLean has lectured internationally on surgery and wound care, and is board certified in both, with a sub-specialty in foot orthotic therapy.