Tips, Tricks, and Pearls for MIS Hammertoe Surgery

Insights from the Teachings of Noman Siddiqui, DPM

 

Hammertoes are a common forefoot pathology, characterized by a progressive deformity with dorsiflexion of the proximal phalanx on the metatarsal head at the metatarsophalangeal joint (MTPJ) and plantarflexion of the intermediate phalanx on the proximal phalanx at the proximal interphalangeal joint (PIPJ).^1-3 The distal interphalangeal joint (DIPJ) may be dorsiflexed, plantarflexed, or neutral.^1-3 Deformity of these joints can be reducible, semi-rigid, or rigid.
 
Treatment is typically initiated by conservative measures such as accommodative shoe gear, use of orthotics, activity, medication, or padding. Given the progressive nature, particularly in cases with hallux valgus, surgical intervention is necessary when one desires to correct the deformity.^4-6
 
Traditional surgical interventions are well-detailed in the foot and ankle literature and are typically represented as open procedures with extensive dissection. While there is a plethora of literature available regarding open techniques for hammertoe correction, there is a lack of literature discussing minimally invasive techniques due to the still-uncommon nature of the procedure.1-6 Advantages to minimally invasive techniques include minimal soft tissue dissection with preserved vascularity, maintaining the stability of the osteotomy, and early weight-bearing and mobilization, particularly of the MTPJ.^7-10 These techniques can lead to increased patient satisfaction and excellent outcomes, as we have seen in our experience.
 
Noman Siddiqui, DPM, has been performing minimally invasive techniques since 2012,and has been performing minimally invasive hammertoe surgery since 2017. We routinely perform PIPJ arthrodesis for our hammertoe corrections. The goal of this blog is to present a systematic case guide that provides surgical tips, tricks, and pearls for our approach to minimally invasive hammertoe correction.

A Stepwise Surgical Approach to MIS for Hammertoes (PIPJ Arthrodesis)

The patient is placed in a supine position with a sterile bump under the knee allowing for approximately 30–45 degrees of knee flexion. The lower extremity is prepped in the usual aseptic fashion above the level of the knee. The procedure begins with fluoroscopy-assisted identification of the PIPJ of the affected hammertoe.
 
Step 1: A 1-cm incision is made along the medial aspect of the proximal interphalangeal joint with a #64 Beaver blade (Beaver-Visitec International) followed by blunt dissection into the joint (Figure 1).
 
Step 2: A 2.0- x 8.0-mm straight burr is inserted into the PIPJ and confirmed fluoroscopy. The burr is inserted in the intra-articular space while holding the toe between the index finger and thumb to denude all cartilage in the joint (Figure 2).
 
Step 3: A 3-mm percutaneous incision is performed at the distal pulp of the toe. We insert the burr into the center of the distal phalanx to serve as a pilot hole similarly to how we ream for intramedullary nailing. This allows for easy pass of the wire down to the proximal phalangeal base (Figure 3).
 
Step 4: A cannulated 2.5-mm screw is then placed into the toe. If there is DIPJ contracture, then this is incorporated into the arthrodesis (Figures 4a-b, Figures 5a-b).
 
Step 5: A flexor tenotomy is commonly performed to prevent latent mallet toe. If there is remaining MTPJ contracture, we will make 1-cm linear incision at the level of the MPTJ.

What the Postoperative Protocol Entails

Postoperatively, patients are placed in a flat surgical shoe and bear weight as tolerated is allowed, with care taken to avoid heel-toe propulsion gait. The patient may bear weight on the heel for comfort (if preferred). The first postoperative visit is generally at 2 weeks, at which time patients are advanced to weight-bearing in supportive athletic shoe gear if edema and incisions allow. If in conjunction with minimally invasive bunion correction, at 10–12 weeks impact activities can be started, depending on clinical and radiographic healing. If isolated hammertoe correction is performed, typically 6 weeks is when patients can return to normal activity if radiographically healed.

In Conclusion

Minimally invasive techniques have made strides within our profession. Our patients report satisfaction and moreover, they are excited about being able to walk in a postoperative shoe immediately after surgery, then transitioning to sneakers within two weeks. Patients further attribute their satisfaction to the cosmetic incision, immediate postoperative weight-bearing, and return to full activity. The high rate of patient satisfaction directly contributes to the surgeon’s satisfaction, as does the decreased narcotic use, decreased operating room time, and the reproducibility with this procedure.
 
Minimally invasive surgery is a safe, reproducible, and viable method to correct hammertoe surgery. We continue to make improvements to this method and these new advances can be performed effectively if surgeons do not deviate from surgical technique.
 
Dr. Mateen is a Fellow at the International Center for Limb Lengthening in the Rubin Institute for Advanced Orthopedics at Sinai Hospital of Baltimore.
 
Dr. Siddiqui is the Chief of the Division of Podiatry at the International Center for Limb Lengthening at Rubin Institute for Advanced Orthopedics at Sinai Hospital of Baltimore. He is the Director of the Foot and Ankle Deformity Correction and Orthoplastics Fellowship and the Director of Podiatric Surgery at the International Center for Limb Lengthening at Rubin Institute for Advanced Orthopedics at Sinai Hospital.
 
References
1.     McGlamry ED, Jimenez AL, Green DR. Lesser ray deformities, Part 1: deformities of the intermediate digits and the metatarsophalangeal joint. In: Banks AS, Downey MS, Martin DE, et al, eds. McGlamry’s Comprehensive Textbook of Foot and Ankle Surgery. 3rd ed. Philadelphia: Lippincott Williams & Wilkins; 2001: pp. 253–304.
2.     Coughlin MJ, Dorris J, Polk E. Operative repair of fixed hammertoe deformity. Foot Ankle Int. 2000;21:94–104.
3.     Kramer WC, Parman M, Marks RM. Hammertoe correction with K-wire fixation. Foot Ankle Int. 2015;36(5):494-502.
4.     Cicchinelli LD. Hammertoe surgery and the Trim-it Drill pin. Foot Ankle Spec. 2013;6(4):296-302.
5.     Albright RH, Hassan M, Randich J, et al. Risk factors for failure in hammertoe surgery. Foot Ankle Int. 2020;41(5):562-571.
6.     Kernbach KJ. Hammertoe surgery: arthroplasty, arthrodesis or plantar plate repair? Clin Podiatr Med Surg. 2012;29(3):355-66.
7.     Vernois J, Redfern DJ. Percutaneous surgery for severe hallux valgus. Foot Ankle Clin. 2016; 21(3):479– 493.
8.     Siddiqui NA, LaPorta G, Walsh AL, Abraham JS, Beauregard S, Gdalevitch M. Radiographic outcomes of a percutaneous, reproducible distal metatarsal osteotomy for mild and moderate bunions: a multicenter study. J Foot Ankle Surg. 2019;58(6):1215-1222.
9.     Siddiqui NA, Mayer BE, Fink JN. Short-term, retrospective radiographic evaluation comparing pre- and postoperative measurements in the chevron and minimally invasive distal metatarsal osteotomy for hallux valgus correction. J Foot Ankle Surg. 2021 Nov-Dec;60(6):1144-1148.
10.  Patel R, Siddiqui N, Dreyer MA, Lam K, Ayyagari V, Onica A. Radiographic and cadaveric analysis of minimally invasive bunionectomy osteotomy position-"MIS bunion sweet spot". Foot Ankle Spec. 2022 Jun 22:19386400221101950.