Point-Counterpoint: Is Fusion The Best Option For Crossover Toe Deformity?
Yes, this author says surgeons can successfully incorporate arthrodesis in the repair of this deformity. He says a strong knowledge of the second toe anatomy and other influencing structures can facilitate good treatment outcomes.
By William D. Fishco, DPM
In theory, surgery on the toes sounds pretty simple. After all, how hard can it be? Technically speaking, we consider toes to be “easy,” especially when we first start out in residency training. Most of us remember getting our first chance handling a scalpel while performing toe surgery. However, anyone who has been in practice for awhile has seen his or her share of less than favorable results following hammertoe surgery. Indeed, digital surgery can be quite a humbling experience for even the most seasoned foot surgeons.
Hammertoe surgery of the second digit, in particular, can be the most challenging. This is partly due to abnormal biomechanics (first ray function) and influences from the great toe. When considering hammertoe surgery on the second toe, the sagittal plane component is rather straightforward. However, medial drift and eventual crossover toe deformity represent the hard part. There is not a procedure or group of procedures that works every time but understanding the anatomy and function of the structures influencing the second toe can help one in procedure(s) selection.
When dealing with a crossover deformity, there are a number of things to consider. Certainly, if there is concomitant first ray pathology, then one needs to correct that concurrently with the second toe surgery. For example, in the case of a dysfunctional first ray, whether it is hallux abductovalgus, hallux limitus or metatarsus primus elevatus, the second metatarsophalangeal joint will be abused, owing to lesser metatarsal overload. This lesser metatarsal overload leads to a cascade of events that may start out as predislocation syndrome and ultimately evolve into a crossover deformity. Moreover, certain structural abnormalities, such as a short first ray or long second ray, have an impact on the second toe joint. This can be congenital or from prior surgery. Often, one will see a medial pull of the second toe, which is probably due to strain on the intermetatarsal ligament.
There are two schools of thought when it comes to hammertoe surgery, namely arthrodesis versus arthroplasty. I am a proponent of digital arthrodesis for the correction of most hammertoe deformities. The main exceptions include the fifth toe and in the case of a relatively inactive geriatric patient who is getting an ulcer on the toe or simply can’t get a shoe on the foot without pain. This type of patient does well with a simple arthroplasty. In this instance, appearance and/or function is not as important as pain relief.
Understanding The Role Of The Long Flexor Tendon
There has been debate about the cause of crossover deformity. In the past five to 10 years, plantar plate insufficiency has gotten a lot of attention as being the culprit. Others blame a tight, long extensor tendon for causing imbalance to the toe. Certainly, we do not understand everything and there may be a number of structures and influences that ultimately may cause the second toe to drift medially. It is my personal opinion that the long flexor tendon is the key structure to understanding the second toe.