There are two procedures I absolutely loathe doing, namely calcaneal fracture repair and Lisfranc’s arthrodesis. I do these procedures reluctantly. However, they are no fun to perform and can be postoperative nightmares no matter how well things heal. While hammertoe surgery is much less technically challenging, it is just a notch below on my list of least favorite surgeries. Any first-year resident could do a hammertoe surgery but let him or her try to manage these patients post-operatively and then the resident will really learn something.
This is where the headaches begin and continue. You may see stiffness, non-purchasing digits, too straight toes, toes that go every direction possible when the K-wire comes out, prolonged swelling, pain, and the infamous “dead stick” toe.
I did my residency 19 years ago and was trained by some very good surgeons. I would like to thank all those who shared their knowledge with me. These surgeons included Richard Lundeen, DPM, Anthony Miller, DPM, Elliott Kleinman, DPM, Jordan Ross, DPM, Tom Vogel, DPM, and Theodore Morden, DPM.
I was primarily trained to do arthroplasties with K-wire fixation that was left in for three to six weeks depending on the surgeon. I always try to do a flexor tendon transfer when possible as it is my first choice for a hammertoe surgery. However, when bone work is needed, that is when I have seen less than reliable results.
When I graduated from my residency, I did arthroplasties with K-wire fixation for six weeks. Four or five years into practice, I was disappointed with my hammertoe surgery results and started doing arthrodesis with K-wire fixation. I did end-to-end arthrodesis with minimal joint resection and left the K-wire in for six weeks. I had many patients complain of toes that were too straight and stiff (i.e. the “dead stick” toe). About three or four years ago, I switched back to arthroplasties with K-wire fixation for six weeks. The disappointment continued until I stumbled upon the Smart Toe by Memometal (MMI).
First, I want to state that I have no conflict of interest with MMI. I am solely writing about this product because I think it is a vast improvement for boney hammertoe surgery. The Smart Toe is made of Nitinol metal and is a one-piece implant (unlike the Stay-Fuse) and is much easier to insert. The angled version, which is the only model I recommend, is angled in 10 degrees of plantar flexion. This gives the toe a more natural appearance and ground purchase. The implant provides rotational stability unlike resorbable pins and K-wires. The implant eliminates external exposure, thereby reducing pin tract infection. The Smart Toe provides compression of the arthrodesis site, reducing the risk of non-unions.
Patients hate K-wires sticking out of their toes and dread having them removed no matter what you tell them. To me, this is a win-win situation. The patient is happy and you get predictable post-operative results. It is about time.
The technique is relatively simple. To begin, start with a dorsal approach. I have used both the longitudinal approach and transverse approach. I will say the longitudinal approach is easier due to better exposure. Utilize a standard joint approach with minimal joint resection in an end-to-end fashion. Drill both sides of the fusion site with the drill bit included in the set, and use the starter awl to prepare the fusion site. Proceed to broach the respective sides. (On a side note, MMI needs to put a “P” and “D” on the broaches instead of the ridiculous pictures they have on the broaches now.) Anyway, the short broach is for the proximal side and long broach is for the distal side.
The implant is frozen and one must insert it within two minutes or the stems will start to open up on both sides of the implant. Use the forceps provided to grasp the implant and insert the proximal stem first. While holding the distal ends together with the forceps near the body of the implant, insert the distal aspect into the middle phalanx. Remove the forceps from the implant and compress the arthrodesis site manually.
The implant is press fit and will be snug going in both sides. Use steady pressure until both sides are completely seated. Hold the fusion site together in order to allow the body heat to activate the Nitinol metal, expanding the head and feet of the implant for about one minute. Close the extensor complex and skin in your preferred manner. Postoperatively, it is recommended to have the patient be ambulatory in a surgical shoe for four weeks.
What is the downside with Smart Toe? The only thing I can really think of is the cost may be prohibitive in certain facility settings. That is it for me.
Just to make it clear, I am only recommending the angled implant. I encourage you to give this a try on a future hammertoe surgery and let me know what you think.