The position of the heel can have a significant influence on the biomechanics of the foot. Rearfoot varus describes the position of the heel bone (calcaneus) when the heels are turning in towards each other. To use a simple stick figure representation, if the patient has a rectus position (alignment straight up) the heel would look as follows; ( l l ). If the patient is in a varus heel position, the heels would appear to turn towards each other ( \ / ). Rearfoot varus can contribute to ankle sprains, peroneal tendon injuries and chronic shoe wear.
The assessment of rearfoot varus should be performed both weight bearing and non-weight bearing. In the non-weight bearing examination, the patient should be prone. It often helps to use a marker to place a line down the back of the heel and more accurately determine rectus vs varus positions.
Compensated, partially compensated and uncompensated calcaneal varus related to the ability to manually reduce rearfoot varus. For instance, while the patient is prone, can the provider move the heel from a varus position to a rectus position? Is that movement of the heel, or what is called reduction of the position, partial or complete? Or does the heel even move at all? I think you can see where we’re going with this. No reduction of the varus indicates uncompensated rearfoot varus. Slight reduction of the heel is partial compensation of the varus deformity. And full reduction of the varus deformity would be described as compensated rearfoot varus.
If we can determine that a patient’s rearfoot varus is partially, fully compensated, or uncompensated, how is that information used to formulate a treatment plan? Partially and fully compensated rearfoot varus can be treated with conservative care including a heel wedge of lateral sole wedge. Remember that the motion in the heel allows for us to wedge the heel into a corrected position, improving foot function. Another common treatment used to correct partially or fully compensated rearfoot varus is to deepen the heel seat of a prescription orthotic and to add a valgus post to the orthotic device.
Uncompensated rearfoot varus responds poorly to wedging or posting of orthotics. Uncompensated rearfoot varus responds best to surgical correction of the deformity. Surgical techniques used to correct uncompensated rearfoot varus include a calcaneal displacement osteotomy or Dwyer procedure.
Rearfoot varus is just one of the biomechanical characteristics of the foot taken into consideration by your lower extremity health providers. Be sure to talk to your lower extremity health specialist for more information regarding rearfoot varus and treatment options.
Jeffrey A. Oster, DPM