Hammertoe surgery is a mainstay in every podiatrist’s office. I have personally found that hammertoe surgery is among the most challenging surgery we perform. Although the surgery is seemingly simple, the results are not as predictable as other surgeries that we do. When we look at each toe individually, there are inherent challenges that each one possesses.
The second toe is complicated due to the influence of the first ray. Concomitant hallux valgus or other pathologies that cause a dysfunctional first ray may contribute to lesser metatarsal overload affecting the plantar plate of the second metatarsophalangeal joint (MPJ).
Therefore, we are trying to deal with not only a proximal interphalangeal joint (PIPJ) contracture but a transverse plane deformity causing medial drifting of the second toe. This occurs as the plantar plate ruptures and causes the flexor tendons to deviate medially. I think we can all agree there are few things more challenging than obtaining a good, long-lasting result in a crossover deformity of the second toe.
I have found the third toe to be the easiest of the lesser toes to address. The difficulty with the third toe arises when there is such a severe crossover deformity of the second toe that the third toe begins to cross over as well.
There is a unique problem with the fourth toe as one may see an adductovarus deformity, which is caused by over pulling of the long flexor tendon. We are all familiar with this deformity occurring commonly with the fifth toe but I believe it is underestimated when it comes to deformity with the fourth toe. This particular problem may not be that obvious before surgery but it may be worse after surgery.
In surgery, you fix the hammertoe with a proximal interphalangeal joint (PIPJ) fusion or arthroplasty, and it looks fine. You pin your toe with a K-wire and you feel good about it. After pulling the pin, you will start to see the distal interphalangeal joint (DIPJ) starting to curl in adductovarus rotation. This is similar to developing a mallet toe after a PIPJ fusion of the second, but since the pull of the flexor tendon is less oblique on the second, you generally do not get the adductovarus influence that you tend to get on the fourth toe. This postoperative deformity is oftentimes asymptomatic but sometimes the toe can be irritated by undermining the third toe.
Key Considerations With The Fifth Toe
Finally, the fifth toe generally has more decision-making steps involved than the third or fourth toes. The considerations of the fifth toe include adductovarus deformity. Does the fifth toe purchase the ground on weightbearing? Is there hypertrophy of the lateral aspect of the middle phalanx? What is the pattern of the corn on the toe?
I think we have all been guilty of “going through the motions,” so to speak, with the fifth toe. Since we never fuse the fifth PIPJ as we may do on the central lesser toes, it is easy to fall into the trap of just doing an arthroplasty of the PIPJ and calling it a day. Unfortunately, the lack of critical evaluation of the fifth toe may lead to a less than optimal result following surgery.
When it comes to the fifth toe, one may consider a derotational skin plasty for adductovarus deformity as well as extensor hood recession with capsulotomy of the MPJ for a toe that does not purchase the ground. If that maneuver does not alleviate the problem, then consider doing a plantar skin wedge resection in the sulcus to aid in pulling the toe down and/or perform a dorsal skin plasty to lengthen the skin if you feel there is a skin contracture. If the corn is very diffuse along the dorsal and lateral toe, then evaluate the middle phalanx as you may need to do a lateral hemiphalangectomy along with the PIPJ arthroplasty.
Salient Tips On Attaining Positive Outcomes With Hammertoe Surgery
The following includes tips on hammertoe surgery that I have learned and would like to share with you.
• I prefer fusions for toes two, three and sometimes four.
• Keep the toes long. Do not take excessive bone off the proximal phalanx.
• When considering buried internal fixation, whether it is a Smart Toe (MMI) implant or a simple K-wire, avoid using them in any toe that has or will have adductovarus deforming force. The adductovarus forces may break your hardware or may cause the implant to break through the middle phalanx. This usually occurs in the fourth toe. So beware of using any buried fixation on the fourth toe.
• If you are going to do hammertoe surgery on toes two and three, you will be better off in the long run to do all the lesser toes. This is because the toes that have not been fixed will appear to be worse since the fixed toes will be straight.
• If there is a crossover deformity or significant transverse plane deformity of the toes, assess the corresponding metatarsal for excessive length. In this instance, a metatarsal osteotomy with metatarsal shift toward the deformity (such as a medial shift of the second metatarsal head in a crossover hallux deformity) along with hammertoe repair will be helpful in addressing the deformity.
• Simple arthroplasty of the central toes without fixation is acceptable in the senior citizen patient population where the decision to perform surgery is to allow them to wear a shoe or prevent ulceration of a toe.
• Always assess the MPJ for contracture and address that with an extensor hood recession and capsulotomy. A simple stab tenotomy and capsulotomy at the MPJ will not work in the long run.
Just remember that the main causation of pathology that you are correcting is the flexor tendon to the toes. It is not a tight extensor tendon that hammers a toe or creates a floating toe. It is not the extensor tendon that causes a crossover toe or adductovarus deformity. It is not a tight MPJ capsule or tight intrinsic muscles that cause a hammertoe. These conditions develop over time due to the deformed state of the toe. If a tendon or capsule does not have stretch to it, then it will shorten or contract.
What is the bottom line? We need to reestablish a normal position of the toe without deformity (via bone work) and prevent the flexor tendon from causing abnormal forces on the toe. Obviously, this is easier said than done.