Hammertoe Surgery: Can Emerging Advances In Fixation Have An Impact?
The treatment of painful hammertoes has dramatically changed in the past several years. What used to be a troubling and often difficult problem to correct has improved to the point that correction is consistent and there is far less pain and difficulty with the return to full function.
Accordingly, let us take a closer look at a treatment algorithm for the treatment of hammertoes and associated problems.
The underlying cause of hammertoes is not fully understood but the general thinking is quite simple. There is a noted imbalance between the stability of the flexor and extensor tendon function in the foot. In addition, there may be an associated lack of proper function of the intrinsic muscles of the foot, which adds to the instability of the foot and toes.
The problem seems to be related to differing muscle imbalances in different types of feet. In high arch feet, there is a very strong extensor trying to dorsiflex the forefoot. This causes a buckling of the metatarsophalangeal joint (MPJ) and flexor contracture secondary to the dorsal MPJ motion. In flat feet, the problem is associated with increased function of the flexor tendons attempting to stabilize the flat foot. This results in hammering of the toes. Of interest is a third and less considered problem associated with a tear of the plantar plate at the associated MPJ with subsequent hammertoe formation and possible MPJ dislocation.
For proper surgical correction, physical examination and proper testing are required. Initial testing requires adequate assessment of the function of the flexor and extensor tendons, stability of the associated MPJ joints and the rigidity of the hammertoe.
Extensive testing is rarely required. The surgeon can use radiographs to check the position and level of deformity. One can also use radiographs to check MPJ alignment and evaluate for possible dislocation. If there is a suspicion of MPJ dislocation due to a plantar plate tear, use magnetic resonance imaging (MRI) to check the integrity of the plantar plate and intrinsic surrounding structures.
Establishing Key Surgical Goals
Hammertoe correction involves multiple factors for adequate aesthetic and functional correction of the underlying deformity. In order to correct a hammertoe, proper alignment and stability are of primary concern.
I prefer fusion procedures to arthroplasty in all but the first toe. This allows for better alignment, reduced edema and improved long-term position. Due to shoes and proper fit in shoegear, an arthroplasty of the first toe seems to work better than fusion procedures.
A second point of great concern is ensuring good function of the toe with proper grasp of the ground and dorsal/plantar alignment. In such cases, one would perform hammertoe correction with sequential releases of the surrounding structures to correct the dorsal/plantar alignment. This facilitates proper ground purchase.
The first structure one should release is the dorsal extensor tendon. If the toe is dorsiflexed, perform a release of the dorsal MPJ capsule. I prefer not to transect the extensor tendon and try only to lengthen the extensor if the dorsal MPJ capsule release is not successful. If the second metatarsal is too long, I will shorten the second metatarsal for proper toe purchase. If the plantar plate is torn, I will then perform a flexor tendon transfer. I find that this sequence leaves very few cases of uncorrectable deformity.
The only time I find that correction is not possible with the aforementioned sequence is in cases of severe MPJ dislocation in which the only option for proper repositioning is an associated metatarsal head resection.