Wednesday, January 6, 2010

Bunions are Genetic, Aren’t They?

This question can be heard multiples times per week in a Podiatrists’ office, and the answer to the questions is: No, not exactly! Bunions have a variety of etiologies that can act alone or in combination with one another causing deformity of the first ray (1st metatarsal and bones of the 1st toe). Just because Mom or Pop may have a bunion, you didn’t inherit your bunions from them, you inherited their abnormal foot type.

Lets take a step backwards for a minute and talk about what exactly a bunion is. Hallux Abducto Valgus (bunion) is a triplanar, progressive deformity of the first metatarsal in which the hallux (great toe) is deviated towards the lesser toes (abducted) and rotated (valgus). HAV is one of the most common pathologies found in the lower extremity and is found in females more often than males by about a 4:1 ratio.

The most common etiology can be classified as a biomechanical abnormality: any condition whereby the 1st ray cannot function optimally in comparison to the normal or rectus foot. This encompasses a variety of pathologies including a hypermobile first ray (excessive motion of the 1st metatarsal and its articulations within the foot), inflammatory conditions of the 1st joint, neuromuscular diseases, an elevated first ray (met primus elevatus), and metatarsus adductus (medial deviation of metatarsals 2-5), to name a few. These inherited conditions prohibit the foot from functioning optimally and your body is forced to compensate for such abnormalities leading to the formation of a bunion. Thanks Mom and Dad!!

Some other less common etiologies of Hallux Abducto Valgus include post-surgical malformation, equinus (inability to dorsiflex the ankle greater than 10 degrees past neutral), limb length discrepancies, and a history of trauma to the hallux.

To prevent the occurrence of bunions, one of the predisposing conditions must be identified and corrected early on, or avoided all together. Unfortunately, this is not typically the case with inherited biomechanical abnormalities. The conditions go unnoticed or are brushed-off as something that the child will “outgrow.” Most pediatric foot abnormalities will not be outgrown and early evaluation and identification of a pathology by a Podiatrist can allow the child to be monitored and/or treated conservatively throughout their development.

Treatments options include a vast array of choices from conservative to surgical and the choice depends largely on the patients pain and discomfort in combination with a physical and clinical examination of the condition. Your Podiatrist will ask you a variety of questions to determine how fast the deformity is progressing and what methods of treatment, if any, you have previously tried. They will examine the deformity clinically to determine where the pain is localized, the degree of soft tissue involvement, the condition of the joint, the rigidity of deformity, and the underlying etiology. Your Podiatrist will also take bilateral radiographs of your feet to evaluate the joint and bone positions in comparison to “standard” radiographic angles.

Once all the pieces of the examination have been considered together, it is most likely that conservative options will be exhausted prior to surgical intervention. Conservative treatments include: injections to decrease inflammation and alleviate pain; padding of the toe to decrease pressure with shoes; physical therapy to increase the range of motion at the joint and eliminate muscular imbalances that may be a causative factor; and orthotics, which attempt to realign the foot in a more optimal position decreasing the biomechanical abnormality that may be the root etiology of your HAV.

If the deformity is rigid and severely progressed, or if conservative treatments have been exhausted without resolution of pain, surgical options become a consideration. Next week we will discuss the types of surgical procedures that may be performed in treating your bunion, the pros and cons of such surgeries and the pre-operative and post-operative courses that should be expected.