Although hammertoes are a common surgical pathology addressed by podiatric surgeons, recurrence can be problematic and frustrating. Accordingly, these authors review common etiologies, keys to assessment and essential pearls to facilitate successful revision.
Recurrent deformity and persistent pain following hammertoe reconstructive surgery is frustrating for both the patient and surgeon. The surgeon typically restores normal digital alignment intraoperatively yet some patients experience deformity recurrence in the early postoperative phase while others struggle with late-stage hammertoe recurrence.
Revision surgery is generally more challenging and extensive than the index procedure, and requires a comprehensive workup and surgical plan. This is especially the case when there is adjacent digital deformity such as hallux valgus or a global digital contracture. The patient and surgeon should have realistic goals in these cases since revision surgery may resolve pain, but may not restore normal digital alignment. The opposite may also be true when deformity improves but the patient struggles with ongoing pain or stiffness.
Hammertoes are an extremely common deformity of the lesser toe with more than 60 million patients suffering from this pathology. With an estimated 550,000 patients having surgical correction of hammertoes in 2012 (comprising roughly 48 percent of all forefoot surgeries), a surgeon must be able to identify and correct the initial deformity.1 However, as with any procedure, surgical cure is never guaranteed and the surgeon must be able to plan for outcomes that may include recurrent deformity despite proper initial treatment.
Comparing the rate of recurrence among the various hammertoe procedures is challenging due to highly variable preoperative pathology. For instance, a patient having extensive procedures like interphalangeal joint fusion, a Weil osteotomy and plantar plate repair has a much more complex problem in comparison to a patient having a simple tenotomy or capsulotomy procedure.
With that in mind, reported outcomes for hammertoe repair include a recurrence rate of around 10 percent with soft tissue manipulation and up to 17 percent patient dissatisfaction with proximal interphalangeal joint arthroplasty.2-5 Malalignment is a major factor in unfavorable results with arthrodesis.2-5 Outcomes assessment is further complicated by the fact that many hammertoe operations include multiple second ray procedures in addition to repair of adjacent pathology.
Predictive factors for recurrence include larger transverse plane deviation, second toe operation and proximal phalanx arthroplasty.6 However, operating on the first ray concomitantly can reduce hammertoe recurrence by up to 50 percent.6
Key Components To Evaluating Hammertoe Recurrence
The first step to successfully address hammertoe recurrence is a systematic approach to history, physical exam and radiologic workup focused on identifying what factors led to recurrence. History of past procedures, the timing of recurrence (early or late stage), preoperative complaints, implantable materials and intraoperative findings are especially helpful if you did not perform the index procedure.
Hammertoe deformity is multifactorial with symptoms differing from patient to patient. There are several underlying systemic etiologies that can contribute to hammertoe deformity and they include diabetes mellitus, neurological disorders, inflammatory arthritis, lumbosacral disc disease and postural abnormalities. With this in mind, the surgeon must rule out these underlying entities as the culprit for recurrence or progression of the hammertoe. With multiple different pathologic processes as well as an abundance of surgical treatment options, understanding the patient as a whole and the reason for failure of an initial procedure is no simple task.
The physical exam should focus on current deformity, location of pain, soft tissue lesions or scars, and underlying pathology. Toe alignment, including the adjacent toes, is of particular interest as the extent of revision surgery frequently requires a more global forefoot reconstructive approach. One should also assess for plantar plate failure, transverse plane MPJ drift, second metatarsal overload, first ray insufficiency, ankle equinus and neurologic involvement (see second photo above).
X-rays will allow further assessment of the aforementioned factors, especially when one is looking at overall foot structure and alignment. Retained hardware will frequently require removal but this may be challenging with intramedullary devices surgeons employ for proximal interphalangeal joint fusion. One may employ advanced imaging, including magnetic resonance imaging (MRI), arthrogram and magnetic resonance (MR) arthrogram, to evaluate for a suspected plantar plate tear. The presence of degenerative changes at the MPJ poses a particular challenge when performing primary or revision surgery since there are relatively few options available.
In cases involving prior proximal interphalangeal joint fusion, revision surgery is more likely to target the MPJ to address residual or recurrent deformity. This can range from simple tenotomy and capsulotomy to full soft tissue reconstruction including metatarsal osteotomy (see bottom photo above). With this in mind, let us take a closer look common scenarios of hammertoe recurrence, surgical treatment strategies and pearls to help prevent recurrence after primary hammertoe repair.
When Plantar Plate Pathology Factors Into Hammertoe Recurrence
Plantar plate pathology is a common cause of recurrent hammertoe deformity. This is a progressive condition and may not have been present at the time of the index procedure. Plantar plate issues are associated with metatarsal elongation, first ray insufficiency, ankle equinus and cavus foot structure that often require treatment at the time of revision hammertoe repair.
A Weil osteotomy can serve as a beneficial option to decompress the lesser MPJ and alleviate plantar pressures of the metatarsal head.7 Osteotomy also allows access for plantar plate repair through a dorsal approach as opposed to using a plantar longitudinal incision (see third photo set above). Both dorsal and plantar access for plantar plate repair often require reattachment of the plantar plate to the base of the proximal phalanx. The key to success with these repairs is proper tensioning, which enables surgeons to achieve both sagittal and transverse plane realignment while avoiding excessive stiffness.
What You Should Know About Interphalangeal Joint Issues And Second Ray Overload
Revision surgery following failure of a PIPJ fusion or arthroplasty site may involve nonunion, malunion and complicated intramedullary devices that are challenging due to concern for bone loss with further intervention. An extramedullary device called ExoToe (ExoToe) allows the surgeon to span the PIPJ after revision surgery and provides stability beyond what one can achieve with K-wires.
Contracture of the distal interphalangeal joint is also common following fusion of the proximal interphalangeal joint. The main treatment approach involves a long flexor tenotomy and distal interphalangeal joint capsulotomy, which one can perform as a simple office procedure. Arthrodesis of the distal interphalangeal joint is a challenge in patients who had a previous proximal interphalangeal joint fusion since there may be excessive stiffness in the toe. Arthroplasty is an option in these cases. The surgeon should consider a distal Symes amputation in situations involving excessive toe length, degenerative joint disease and advanced nail pathology.
Overload of the second ray is common in patients with recurrent hammertoe deformity. This presents as plantar second MPJ pain, callus, plantar plate failure, dislocated second MPJ, second metatarsal stress reaction or fracture on X-ray, and hallux valgus with midfoot instability. Repeat second ray surgery will not work if the surgeon does not recognize and address the first ray pathology. Midfoot fusion is the primary approach to dealing with this situation, which requires preservation of medial column length in order to avoid further second ray overload.8
Pertinent Pearls Regarding Underlapping Adjacent Toes And Neuromuscular Contracture
Adjacent toe deformity, which commonly presents as underlapping of the hallux-associated bunion deformity, can complicate revision hammertoe surgery. A more comprehensive forefoot approach is necessary in this circumstance with the goal of creating space for proper digital alignment.
Fusion of the first MPJ is an option to achieve predictable digital alignment. There are also times when amputation of the second toe is the most straightforward approach to revision hammertoe surgery. This most commonly applies to an older patient who is not a candidate for major bunion repair involving midfoot fusion or osteotomy yet there is no chance of fixing the hammertoe unless one also straightens the first toe. Amputation under these circumstances can heal in two weeks, allow immediate ambulation and is not affected by poor bone quality.
Hammertoe contracture associated with neurologic disorders often requires a different surgical approach in comparison to those caused by biomechanical imbalance. Spasticity, as one may see in cases involving cerebrovascular accident, cerebral palsy or traumatic brain injury, may simply need a flexor release, which allows a simple recovery process in this challenging population (see top photos above).9,10 Failure to appreciate the extent of neurologic involvement will result in recurrence of distal interphalangeal joint and MPJ contracture not addressed by proximal interphalangeal joint fusion.
When Is Amputation A Reasonable Option For Hammertoe Recurrence?
A main indication for digital amputation in the setting of hammertoe recurrence is adjacent toe deformity that would require a more complex approach than is practical for the patient. This could be due to age, comorbid conditions, bone quality concerns and compromised soft tissues.
We discuss this situation above regarding severe hallux valgus with crossover toes. For many patients with this predicament, the deformed toe is a chronic source of daily pain and prohibits activity that is so crucial to good health for older individuals. Offering a simple solution like amputation of a completely non-functional toe is a welcomed option for those less concerned about the cosmetic appearance of their foot. Lesser MPJ advanced arthritis is another reason to consider digital amputation since deformity correction will not solve the problem if the patient will have ongoing joint pain and stiffness proximally at the MPJ level.
It would be ideal if there was one perfect hammertoe operation that consistently avoided recurrence. The aforementioned examples demonstrate that hammertoes present with a variety of underlying causes and associated pathologies, which explains the wide range of procedures in practice today. The MPJ seems to be the main challenge in hammertoe surgery with the desire for stability in the transverse plane, strong plantar plate structures and full range of motion in the sagittal plane. However, these goals are not necessarily compatible considering limited exposure, lack of surgeon control over scar tissue, complex muscle anatomy, high stress forces of ambulation and underlying foot structure issues like cavus or equinus deformity.
Surgeons and patients should have realistic goals when treating recurrent hammertoe deformity, and be willing to address the condition from a global perspective. The second attempt to fix a hammered toe should not be a minimalist approach if that will predispose the patient to a third or fourth procedure, which further complicates the scar tissue dilemma.
Dr. Boffeli is the Foot and Ankle Surgical Residency Program Director and Department Chair at Regions Hospital/HealthPartners Medical Group in St. Paul, Minn. Dr. Boffeli has disclosed that he has ownership in Surgical Design Innovations and is an investor in ExoToe, LLC.
Dr. Nelson is a first-year resident with the Foot and Ankle Surgical Residency Program at Regions Hospital/HealthPartners Medical Group in St. Paul, Minn.
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