Hammertoe Deformity

Updated: Feb 07, 2023
Author: Anthony Watson, MD; Chief Editor: Vinod K Panchbhavi, MD, FACS, FAOA, FABOS, FAAOS 

Overview

Practice Essentials

Hammertoe deformity is the most common deformity of the lesser toes. The fundamental problem is a chronic, sustained imbalance between flexion and extension forces applied to the lesser toes.  These imbalanced forces involve intrinsic and extrinsic tendons of the foot.

With progressive proximal interphalangeal (PIP) joint flexion deformity, compensatory hyperextension of the metatarsophalangeal (MTP) and distal interphalangeal (DIP) joints typically occurs. The hyperextension of the MTP joint and the flexion of the PIP joint make the PIP joint prominent dorsally. This prominence rubs against the patient's shoe and may progress to cause discomfort.

Early in its natural history, the deformity is flexible and passively correctable, but it typically becomes fixed over time. Progressive deformity can lead to MTP joint dislocation. Nonoperative treatment may include the following:

  • Taping
  • Budin splint wear
  • Shoewear modification (with some patients going so far as to cut holes in shoes over the prominence)

Once flexion contractures form, surgical treatment may be indicated. Surgical treatment of hammertoe deformity has historically been based on altering the relative lengths of the toe and its tendons in order to achieve balance between extensor and flexor forces. A main distinction is between the flexible and the rigid hammertoe deformity. Surgical options have included the following:

  • PIP joint resection arthroplasty
  • PIP joint fusion
  • Tendon transfers
  • Tendon lengthening
  • Metatarsal shortening

Metatarsal shortening has gained renewed interest, but PIP joint resection arthroplasty and tendon transfers have been the main procedures for hammertoe correction.

Anatomy

The lesser toe comprises three phalanges that articulate at the PIP and DIP joints. The proximal phalanx articulates with the metatarsal at the MTP joint. Medial and lateral collateral ligaments, a fibrocartilaginous plantar plate, and a thin dorsal capsule stabilize each of the three joints.

The extensor digitorum longus (EDL) tendon originates in the anterior compartment of the leg and crosses the ankle anteriorly. Although it extends all three joints of the lesser toe, it primarily acts at the MTP joint. The extensor digitorum brevis (EDB) originates at the dorsal surface of the calcaneus and blends with the EDL tendon over the proximal phalanx to form the extensor expansion.

The EDL continues distally from the extensor expansion and trifurcates to form the central slip, which inserts onto the middle phalanx, and the lateral slips, which insert onto the distal phalanx and are distinguished by their anatomic location (medial or lateral). The central slip and lateral bands extend the PIP and DIP joints, respectively, when the MTP joint is in neutral position or in plantarflexion. Some authors have found that the lateral slips arise from the EDB tendon in toes 2 through 5.[1, 2]

The flexor digitorum longus (FDL) tendon originates in the deep posterior compartment of the leg, crosses the ankle medially, and flexes all three joints of the lesser toes, though it acts primarily at the DIP joint. The flexor digitorum brevis (FDB) tendon originates from the plantar surface of the calcaneus and primarily flexes the PIP joint. The lumbricals originate from adjacent FDL tendons, pass plantarly to the MTP, and then extend dorsally to coalesce with the lateral bands. Thus, the lumbricals flex the MTP joint and extend the PIP and DIP joints.

The neurovascular bundles of each toe arise from a common interdigital artery and a common interdigital nerve. Each bifurcates at approximately the level of the MTP joint. Each branch then extends along the medial and lateral aspects of the toe deep to the subcutaneous tissue. Both the interdigital artery and the interdigital nerve are plantar to the intermetatarsal ligament at the level of the MTP joint. Both can become contracted in a chronic hammertoe and are subject to traction injury with hammertoe correction.

Pathophysiology

The fundamental problem is a chronic, sustained imbalance between flexion and extension force of the lesser toes from intrinsic forces, extrinsic forces, or both. Hammertoe deformity primarily involves flexion deformity of the PIP joint of the toe, with hyperextension of the MTP and DIP joints (see the image below).

Diagram comparing clinical appearances of lesser-t Diagram comparing clinical appearances of lesser-toe deformities.

When the second ray of the foot is longer than the first and shoewear is improperly fitted, flexion of the PIP joint occurs to accommodate the shoe. This length difference also causes MTP synovitis to develop from overuse of the second MTP joint. Attenuation of the collateral ligaments and plantar plate results, and the MTP joint hyperextends and may even progress to dorsal subluxation or dislocation (see the image below). Rheumatoid arthritis causes hammertoe deformity by progressive MTP joint destruction, leading to MTP joint subluxation and dislocation.[3, 1, 4]

Pathomechanics of hammertoe deformity. Elongated p Pathomechanics of hammertoe deformity. Elongated plantar plate, caused by either metatarsophalangeal (MTP) synovitis and instability or chronic MTP hyperextension due to toe crowding, results in MTP subluxation or dislocation with compensatory proximal interphalangeal (PIP) flexion.

With all three of these etiologies, the EDL tendon gradually loses mechanical advantage at the PIP joint, as does the FDL tendon at the MTP joint. The intrinsic muscles subluxate dorsally as the MTP hyperextends. They now extend the MTP joint and flex the PIP joint, as opposed to their usual functions of flexing the MTP joint and extending the PIP joint.

Etiology

Etiologies of hammertoe deformity include the following:

  • A foot in which the second ray is longer than the first (see the image below)
  • MTP joint synovitis and instability
  • Inflammatory arthropathies
  • Neuromuscular conditions
  • Ill-fitting shoewear
Morton foot, wherein second ray (metatarsal and co Morton foot, wherein second ray (metatarsal and corresponding toe) is longer than first ray.

MTP joint synovitis and instability are associated with a second ray that is longer than the first. Inflammatory arthropathies typically involve more than one of the lesser MTP joints. Ill-fitting shoewear compounds the effects of any of the other causes.

Epidemiology

The incidence of hammertoe deformity is undefined. However, the condition is strongly associated with the presence of a second ray that is longer than the first, and it is known to be more common in women and to increase in frequency with advancing age. Indeed, this length disparity is found in most patients presenting with foot complaints, though the actual prevalence of this foot shape also is undefined.

Prognosis

Patients should be counseled that their expectations for a good result after hammertoe treatment should include the following:

  • Permanent relief of pain
  • Ability to wear reasonable shoes (those of appropriate length, width, and depth for their entire foot) without pain

Although nonoperative treatment of hammertoe deformity often successfully alleviates pain, the deformity typically progresses in magnitude and stiffness despite diligent nonoperative care. Surgical treatment of flexible hammertoe deformity reliably corrects the deformity and alleviates pain. Recurrence and progression are common, especially if the patient resumes wearing deforming shoes. Surgical treatment of fixed hammertoe deformity provides very reliable deformity correction and pain relief. Recurrence is rare after appropriate surgical management. (See the images below.)

Clinical photograph showing correction of deformit Clinical photograph showing correction of deformities involving second and great toes.
Anteroposterior radiograph at 3-month follow-up sh Anteroposterior radiograph at 3-month follow-up showing correction of hammertoe and hallux valgus deformities.
Lateral radiograph at 3-month follow-up showing co Lateral radiograph at 3-month follow-up showing correction of lesser-toe deformity.

Mueller et al evaluated outcomes of operative management of hammertoe deformity in 47 patients, of whom 26 (37 toes) were younger than 65 years and 21 (39 toes) were 65 years of age or older.[5]  They found that both groups showed statistically significant improvement, that the two cohorts were similar with respect to outcomes, and that there was no significant increase in complications in the older patents. 

 

Presentation

History

A patient with symptomatic hammertoe typically complains of pain over the dorsal aspect of the proximal interphalangeal (PIP) joint of the affected toe. Occasionally, the patient also complains of pain over the plantar area of the metatarsal head, especially if the metatarsophalangeal (MTP) joint is hyperextended, subluxated, or dislocated.

A callus may be present over the dorsal surface of the PIP joint, over the plantar surface of the metatarsal head, or at the tip of the toe (see the image below). In addition, patients with MTP joint instability often complain of pain over the dorsal part of the MTP joint, and they may describe the sensation of a lump in the plantar area of the MTP joint.

Painful dorsal callus over proximal interphalangea Painful dorsal callus over proximal interphalangeal (PIP) joint of second toe, caused by long-standing, fixed hammertoe deformity.

Physical Examination

The physical examination of hammertoe deformity must include the following:

  • Neurovascular evaluation, including palpation of pulses
  • Sensory examination, with emphasis on protective sensation
  • Evaluation of intrinsic muscle bulk
  • Assessment of flexibility (is the deformity flexible or rigid?)

The deformity should be assessed while the patient is standing so that its functional significance can be better appreciated. Accompanying deformities, such as hallux valgus, combined hammertoe and rotational deformity, and cavus foot deformity, must be catalogued. Passive correction of the deformity should be attempted because this will help determine which treatment options are appropriate for the patient.

Palpate both the plantar and articular portions of the metatarsal head, because patients with MTP instability have greater tenderness of the articular portion and may require treatment different from that of patients with isolated hammertoe. Pain with dorsal subluxation of the MTP joint implicates MTP instability (see the image below). Palpate the webspace, and compress the forefoot by squeezing the metatarsals together from medial to lateral. These two maneuvers help exclude an interdigital neuroma, which often is confused with MTP instability.

Physical examination maneuver to diagnose metatars Physical examination maneuver to diagnose metatarsophalangeal (MTP) instability, wherein examiner attempts to translate proximal phalanx dorsally relative to metatarsal head. In most patients, subluxation is possible; therefore, this test is positive only when it causes pain.
 

DDx

Diagnostic Considerations

Surgeons should be able to distinguish between flexible and fixed hammertoe deformities, as well as mallet toe, claw toe, and curly toe deformities. Furthermore, isolated hammertoe should be distinguished from autoimmune forefoot disease.

 

Workup

Laboratory Studies

If inflammatory arthropathy is suspected, serologic evaluation should be considered. Tests include evaluation of rheumatoid factor (RF), antinuclear antibody (ANA), human leukocyte antigen (HLA) B27, and Lyme titers.

Imaging Studies

Radiographic evaluation of hammertoe is not necessary for clinical diagnosis; however, it can be helpful for ruling out alternative diagnoses and can aid in surgical planning. Imaging considerations in the evaluation of hammertoe deformity include the following:

  • Weightbearing anteroposterior and lateral radiographs of the involved foot are useful (see the images below)
  • Intra-articular and periarticular erosions suggest rheumatoid arthritis and psoriatic arthritis, respectively
  • Enlargement of the metatarsal head and osteophytes suggests a previous Freiberg infraction
  • Varus angulation and/or dorsal subluxation or widening of the joint space of the metatarsophalangeal (MTP) joint suggests MTP instability
  • The presence of other deformities should be noted, especially hallux valgus (see the images below), which is associated with the "crossover" toe deformity
Anteroposterior radiograph showing hammertoe defor Anteroposterior radiograph showing hammertoe deformity in second toe and associated hallux valgus deformity in forefoot.
Lateral radiograph showing hammertoe deformity. Lateral radiograph showing hammertoe deformity.

Histologic Findings

Histologic evaluation is typically not available or necessary before hammertoe treatment. Skin ulceration and osteomyelitis may occur in neuropathic patients with hammertoe deformity. Histologic confirmation of osteomyelitis precludes most hammertoe reconstruction procedures.

 

Treatment

Approach Considerations

The choice of nonoperative treatment of hammertoe deformity is based on the flexibility of the deformity (see Medical Therapy). Similarly, surgical treatment of hammertoe deformity depends on the flexibility of the deformity (see Surgical Therapy). The magnitude of the deformity also affects surgical decision-making.

The indication for surgical treatment of hammertoe deformity is disabling pain that does not improve with adequate nonoperative treatment, including taping (for flexible deformity) and the use of accommodative footwear featuring a toe box of adequate depth (for fixed deformity). Surgical correction of an asymptomatic hammertoe may be considered at the time of hallux valgus correction.  

Absolute contraindications for surgery include active infection and inadequate vascular supply. The desire for cosmesis alone is not an accepted indication; the patient must understand that the goal of surgery is pain relief, not cosmesis. Inability to accommodate shoe wear restrictions and/or limitations is a relative contraindication.

As a general rule, flexible deformities are amenable to soft-tissue procedures, whereas rigid deformities require at least a component of bony intervention. Passively correctable deformity is amenable to Girdlestone-Taylor flexor-to-extensor tendon transfer. Fixed deformity requires either proximal interphalangeal (PIP) joint resection arthroplasty or PIP joint arthrodesis. Both flexible and fixed deformities also may require metatarsal shortening, metatarsophalangeal (MTP) joint resection arthroplasty, extensor tenotomy, or a combination of these procedures to achieve adequate correction. A rotational deformity may require the addition of derotational phalangeal osteotomy.

A metatarsal shortening osteotomy may have to be added for a dislocated MTP joint or MTP instability with synovitis. Metatarsal-shortening procedures are becoming more popular as adjuncts to hammertoe correction but have not yet been fully accepted. Choices are as follows:

  • Traditional diaphyseal shortening
  • Posterior translation of the metatarsal head along a transverse plane osteotomy at the metatarsal neck (Weil osteotomy)

The Weil osteotomy is technically easier and less prone to nonunion. Metatarsal shortening also changes the length relationships between the toe tendons and the ray and may help reduce a hammertoe deformity.

Other approaches to managing MTP joint synovitis, instability, subluxation, or dislocation include the following:

  • MTP joint resection arthroplasty
  • Plantar condylectomy
  • MTP plantar plate reconstruction

Medical Therapy

Strapping of the toe with either tape or a commercially available hammertoe sling is helpful for a flexible deformity; however, it mandates the use of shoewear that will accommodate the straps or slings. The tape or sling is placed dorsally over the proximal phalanx, the MTP joint is plantarflexed slightly, and the tape or sling is secured plantarly. The strapping reduces the deformity by exerting a plantarflexion force at the MTP joint, resulting in compensatory extension of the PIP joint.

Fixed deformities are not amenable to strapping, because the deformity cannot be corrected. Extra-depth footwear is necessary to minimize pressure dorsally over the affected toe(s). Lace-up shoes are more comfortable than slip-on shoes (eg, loafers) because a slip-on shoe is necessarily tight in the forefoot to maintain its fit.

Metatarsalgia, or pain over one or more metatarsal heads, may occur with significant deformity. This pain may be alleviated by using an arch pad in the shoe that may redistribute weightbearing force away from the metatarsal heads.

Patients often ask about physical therapy. Although no reliably effective physical therapy program for hammertoe deformity has been described, it may be nonetheless be useful for the patient with a flexible deformity to perform passive stretching exercises.

Hammertoe shield for treatment of flexible hammert Hammertoe shield for treatment of flexible hammertoe. Sling over proximal phalanx straightens toe, while shield under metatarsal head provides padding for painful callus that may be present, supports toe plantarly, and anchors sling.

Surgical Therapy

The flexibility of the deformity determines which technique is appropriate for correction. A flexible deformity of small magnitude may be amenable to a flexor tenotomy. No more than a small flexion deformity of the PIP joint should be present, with no subluxation of the MTP joint. A flexible deformity of greater magnitude requires a Girdlestone-Taylor flexor-to-extensor tendon transfer.[6] This method functions in the same way as taping or strapping a flexible hammertoe. Pin fixation is necessary for 4-6 weeks after surgery.

A fixed deformity requires at least resection arthroplasty of the PIP joint.[7] The goal is to shorten the toe and thereby decrease the deforming forces of the contracted soft tissues. As the magnitude of the deformity increases, additional procedures, such as flexor tenotomy, extensor tenotomy, MTP joint release or arthroplasty, and metatarsal shortening may be necessary. Pin fixation is necessary for 4-6 weeks after surgery.[8, 9, 10]

MTP arthroplasty includes resection of 2 mm of the metatarsal head articular surface and pinning of the toe across the MTP joint. It is theorized that the resulting arthrofibrosis stabilizes the MTP joint.

Plantar condylectomy of the metatarsal head may have to be added for plantar metatarsal head pain without instability or synovitis. Plantar condylectomy with pinning across the MTP joint helps reduce plantar prominence; the prominence may cause pain or callus over the second metatarsal head. Removing the condyles results in a bleeding cancellous bone surface on which the attenuated plantar plate readheres and contracts to stabilize the MTP joint.

MTP plantar plate reconstruction is a more anatomic stabilization of the MTP joint. Reconstruction of the plantar plate is an increasingly popular popular addition to metatarsal shortening when MTP instability is present.11 There is evidence to suggest that the plantar plate has some ability to heal these repairs.[11]

Metatarsal-shortening procedures are most likely to be effective in a foot with a long second metatarsal when second hammertoe is accompanied by pain or plantar callus over the second metatarsal head or when MTP instability and synovitis are present. To achieve adequate correction, it may be necessary to combine other procedures (PIP resection arthroplasty, Girdlestone-Taylor flexor-to-extensor tendon transfer) with the metatarsal shortening. If MTP instability is present, then plantar plate reconstruction should be added.

PIP joint arthrodesis is currently performed with regularity.[12, 13]  Studies are needed to evaluate its results against those of PIP joint resection arthroplasty.[14] Cockup deformity is a frequent complication, especially when significant MTP hyperextension is present preoperatively. 

Special consideration is necessary when hallux valgus accompanies second hammertoe deformity. (See the image below.) Even if the hallux valgus and bunion are asymptomatic, hallux valgus correction is necessary to minimize the risk of recurrence of the second hammertoe.

Severe hammertoe deformity in second toe overlappi Severe hammertoe deformity in second toe overlapping great toe with associated hallux valgus deformity.

When rotational deformity accompanies hammertoe deformity, rotational or angulatory deformity of the involved phalanx may be necessary.

Resorbable pins have been considered for hammertoe correction fixation to avoid the necessity of pin removal in the office. Their strength in this application has not yet been rigorously studied, but success with resorbable pins and screws for other forms of foot and ankle surgery is encouraging.

K-wire fixation is a common, effective, and relatively inexpensive means of treating hammertoe deformity.[15]  (See the image below.) Some have expressed concerns about possible complications associated with K-wire fixation, which have led to the development of a number of permanent implants for fixation.[16, 17]  Although various intramedullary implants (eg, the ToeGrip and the SmartToe) have yielded good results, they remain relatively costly and have not yet been shown to confer clear advantages with respect to pain levels, patient satisfaction, foot-related function, or surgical complication rates.[18, 19, 20]

Intraoperative fluoroscopic image showing correcti Intraoperative fluoroscopic image showing correction of deformities in first and second rays and use of Kirschner wires to stabilize osteotomies.

Preparation for surgery

Preoperative evaluation includes assessment of the following:

  • Circulation, sensation, flexibility and magnitude of the deformity
  • Stability of the MTP joint
  • Associated deformities
  • Metatarsalgia

Palpable pulses indicate an excellent prognosis for healing. Doppler studies should be obtained if pulses are not palpable. An ankle-brachial index (ABI) greater than 0.65 or a toe pressure greater than 40 also indicates a good prognosis for healing. A severe, long-standing, fixed hammertoe deformity can become ischemic when corrected as a consequence of traction on the digital arteries caused by straightening the toe.

Traction on the digital nerves can result in neurapraxia; therefore, preoperative knowledge of the sensory status of the toes is imperative. Patients with sensory neuropathy and good circulation are at risk for Charcot neuroarthropathy of the forefoot or midfoot after surgery. These patients are typically diabetic.

Associated deformities may require simultaneous surgical treatment. An apparent rotational deformity may actually be due to an angulatory deformity of the proximal or middle phalanx and should be assessed carefully on physical and radiographic examination. The location of metatarsalgia should be known preoperatively so that the patient can be counseled about postoperative expectations, because relief of metatarsalgia after hammertoe correction is unpredictable.

Although the clinical data are limited, it has been argued that perioperative antibiotic prophylaxis is not necessary for isolated forefoot procedures (eg, hammertoe correction) in the absence of risk factors (eg, immunodeficiency or diabetes mellitus).[21]

Operative details

Flexor tenotomy

Flexor tenotomy is typically performed via a plantar stab incision at the distal interphalangeal (DIP) joint. The scalpel is centered medial to lateral, and the flexor tendon is transected at its insertion onto the plantar base of the distal phalanx. The PIP joint then is hyperextended to free any adhesions between the flexor tendon and the plantar plate and collateral ligaments of the PIP joint. A smooth 0.045-in. Kirschner wire (K-wire) is then placed in a retrograde manner from the tip of the toe just plantar to the nail plate across the DIP and PIP joints while these joints are maintained in neutral extension.[22]

Bouche and Heit found that flexor digitorum longus (FDL) tendon transfer for combined plantar plate and hammertoe repair was viable in treating severe, chronic sagittal plane instability of the internal lesser MTP joints.[22]

In a study of 54 patients with a proximal planterflexion deformity of the second toe, Frey et al described a percutaneous technique that combined (1) FDL tenotomy, (2) plantar capulotomy for PIP joint release, and (3) proximal phalangeal osteotomy.[23] In the 24 cases where an extension deformity of the MTP joint was present, tenotomy of the extensor digitorum longus (EDL) and extensor digitorum brevis (EDB) was performed. At a mean follow-up of 30.7 months, the satisfaction rate and the rate of morphologic correction were both 89.5%. Active plantarflexion was preserved in 86%.

Girdlestone-Taylor flexor-to-extensor tendon transfer

Girdlestone-Taylor flexor-to-extensor tendon transfer consists of splitting the FDL tendon in half after detaching it from the plantar base of the distal phalanx via a percutaneous stab incision.[6] A second transverse incision is made plantarly at the MTP joint, through which the detached flexor tendon is harvested. It then is split longitudinally along its raphe.

A longitudinal incision is made dorsally over the proximal phalanx. A curved hemostat is passed along the bone on each side of the proximal phalanx to prevent neurovascular injury. Each hemostat grasps one half of the split tendon, and the halves are pulled through dorsally.

The interphalangeal (IP) joints are positioned in neutral extension, the MTP joint is slightly plantarflexed, and a 0.062-in K-wire is passed in retrograde fashion from the tip of the toe just plantar to the nail plate, across the IP and MTP joints, and into the metatarsal. Tension is applied to the transferred tendon halves while slight ankle plantarflexion is maintained, and the halves are sutured to the dorsal soft tissues over the proximal phalanx.

PIP joint resection arthroplasty

PIP joint resection arthroplasty is performed via either an elliptical incision directly over the joint or a longitudinal incision. Recurrence is theoretically less common with the elliptical incision, and the procedure is easier. A longitudinal incision is necessary if exposure of the DIP joint, the MTP joint, or both is necessary.[7]

The elliptical incision is made directly over the PIP joint through skin, tendon, and joint capsule. The incised soft tissues are excised. The head of the proximal phalanx is exposed through release of the collateral ligaments and the plantar plate. A bone cutter, rongeur, or microsagittal saw is used to remove the head of the proximal phalanx at the level of the phalangeal neck.

A smooth 0.045-in. K-wire is placed in an antegrade manner through the middle and distal phalanges while DIP joint extension is maintained. It is then placed in a retrograde fashion into the proximal phalanx while PIP joint extension and distraction are maintained. The skin, tendon, and capsule are closed together as a single layer.

A study by Yassin et al compared PIP joint resection arthroplasty and K-wire fixation (n = 265; 454 toes) with percutaneous diaphyseal osteotomy of the middle and proximal phalanges and tendon release (n = 87; 221 toes).[24]  The two groups were similar with respect to abnormal healing rates, alignment, and patient satisfaction, but patients in the percutaneous group had fewer infections.

Additional procedures

If adequate correction of a fixed hammertoe deformity cannot be achieved with PIP joint resection arthroplasty, additional procedures are necessary. First, extensor tenotomy is performed at the MTP via a dorsal stab incision. Releasing both the extensor digitorum longus (EDL) and the extensor digitorum brevis (EDB) is important. If correction remains inadequate, release of the dorsal MTP joint capsule is performed through the same stab incision. Finally, if additional correction is necessary, the incision is extended and MTP arthroplasty performed.

The Weil osteotomy is an effective metatarsal-shortening method.[25] The osteotomy is started at the junction of the articular cartilage and dorsal shaft of the metatarsal and continued along a plane parallel to what would be the position of the floor if the patient were weightbearing. The metatarsal is translated proximally about 3-4 mm, and screw fixation is placed. The redundant dorsal cortex is then removed.

Plantar plate reconstruction is combined with Weil osteotomy when MTP instability is associated with hammertoe deformity. The plantar plate is detached from the base of the proximal phalanx, and a suture is placed transversely through the plantar plate proximal to the detachment point. The suture is then passed through drill holes in the proximal phalanx from plantar to dorsal while reduction of the MTP joint is maintained.

MTP arthroplasty comprises arthrotomy and exposure of the metatarsal head. A 2-mm wafer of articular surface is removed with a microsagittal saw.

When any of these supplemental procedures are necessary, a smooth 0.062-in. K-wire should be substituted for the 0.045-in K-wire, and it should be placed across the MTP joint into the metatarsal.

Postoperative Care

The pin is bent and cut to length outside the skin. The bent tip should terminate dorsal to the nail plate, potentially preventing proximal migration of the pin. A pin cap protects the sharp end of the cut pin so that it does not catch on the patient's bed sheets. A compression dressing is applied. Plaster immobilization is rarely, if ever, necessary. A hard-soled postoperative shoe is provided. Elevation of the foot with the toes above the nose is essential to minimize swelling, which can cause pain and delay wound healing.

Complications

Complications of hammertoe correction surgery include the following:

  • Infection
  • Delayed wound healing
  • Recurrent deformity
  • Molding
  • Loss of fixation
  • Neurovascular injury
  • Metatarsalgia

Superficial wound infection is not uncommon, given that skin redundancy often occurs after correction of the deformity. Superficial wound infection typically responds to local wound care and oral administration of antibiotics to which typical skin flora are sensitive. Deep infection often requires irrigation and debridement. In severe and complicated cases (eg, in diabetics), deep infections may necessitate amputation.

Pin migration is a known complication. Proximal migration, though more worrisome, is less common. In cases of distal migration, the pins should not be readvanced into bone, so as to avoid pin-associated infection. Severe redness and swelling of the entire toe with drainage suggests infection around the pin. Usually, removal of the pin and a 10- to 14-day course of oral antibiotics to which typical skin flora are sensitive are sufficient. The toe must be taped (see Medical Therapy), and a second piece should be added to maintain extension of the IP joints. Taping should continue as long as the pin would have remained in place.

Delayed wound healing usually occurs in individuals who smoke or in persons with peripheral vascular disease or diabetes. Prevention by means of a thorough preoperative evaluation and optimization minimizes the risk of delayed wound healing. Deep infection in a slowly healing wound should be suspected. Radiography, bone scintigraphy, and indium-labeled white blood cell scanning are not helpful during the early postoperative period. Essential components of treatment include the following:

  • Vigilant follow-up care
  • Debridement when necessary
  • Local wound care
  • Therapy with oral antibiotics to which typical skin flora are sensitive; knowledge of local community and hospital antibiograms is helpful in guiding empiric therapy [26, 27]

Recurrent deformity is common and is typically caused by inadequate correction or use of inappropriate footwear. Salvage commonly requires PIP resection arthroplasty combined with extensor tenotomy and either MTP release or MTP arthroplasty. The results of revision surgery are less reliable than those of primary surgery.

Cockup deformity may occur after PIP arthrodesis if MTP hyperextension is not corrected, or after Weil osteotomy. Floating toe deformity is also a complication of Weil osteotomy, especially when combined with PIP arthrodesis.[28]

So-called sausage toe may occur after Girdlestone-Taylor tendon transfer (see the image below).

"Sausage toe" complication occurring after Girdles "Sausage toe" complication occurring after Girdlestone-Taylor tendon transfer.

Neurovascular injury is extremely rare and typically results from complete correction of a long-standing, severe deformity. Traction from the correction on the neurovascular bundle can cause neurapraxia, vasospasm, or digital artery avulsion.

Because of the collateral circulation, ischemia rarely results. Nevertheless, it is necessary to ensure that the patient does not leave the operating room until all of the toes have "pinked up." If capillary refill does not occur in a given toe, the dressing should be loosened. If this is unsuccessful, the toe should be warmed. If capillary refill does not occur, the pin should be bent to partially recreate the deformity, thereby reducing tension on the neurovascular bundle. The pin may have to be removed. Finally, exploration for persistent bleeding or a compressive hematoma may be necessary.

Nerve injury can result in anesthesia, dysesthesia, or hyperesthesia. Anesthesia is well tolerated, and dysesthesia is accepted, but hyperesthesia can be disabling and may represent a variation of chronic regional pain syndrome. Neurogenic pain may be of sufficient severity to warrant toe amputation.

Metatarsalgia, a complication of many forefoot procedures, develops as diffuse pain over the metatarsal heads. It is often caused by an altered gait pattern occurring after the patient resumes weightbearing in a regular shoe. Metatarsalgia is often self-limiting. However, patients may require orthotic management consisting of a cushioned longitudinal arch support to relieve the metatarsal head.

Long-Term Monitoring

Weightbearing, as tolerated in a hard-soled shoe, is permitted when the pin does not cross the MTP joint. Weightbearing is not permitted when the fixation pin crosses the MTP joint. Footwear may be advanced as tolerated once the pin is removed (typically 4-6 weeks after surgery). A compressive dressing is used until the sutures are removed 10-14 days after surgery. The patient should understand that mild-to-moderate swelling persists for many months after surgery and limits footwear options until it has resolved.

All lesser-toe procedures result in stiffness of the MTP and IP joints. Because some stiffness is intentional for maintaining lasting correction of the deformity, exercises to improve range of motion should be used judiciously. Some stretching may be necessary to improve mobility, but general mobilization ("real-life physical therapy"), as tolerated, is usually sufficient.

Patients should be counseled to continue wearing shoes of adequate length and depth, with a rounded or squared toe area to minimize the risk of recurrence. Temporary plantar foot discomfort may occur for several months after surgery in patients who undergo an MTP joint procedure. The wearing of stiff-soled shoes with a metatarsal pad is usually sufficient until the symptoms abate.

 

Questions & Answers

Overview

What is a hammertoe deformity?

How is hammertoe deformity treated nonoperatively?

What are the surgical treatments for hammertoe deformity?

What is the anatomy of the phalanges relevant to hammertoe deformity?

What is the pathophysiology of hammertoe deformity?

What causes hammertoe deformity?

What is the prevalence of hammertoe deformity?

What is the prognosis of hammertoe deformity?

Presentation

Which clinical history findings are characteristic of hammertoe deformity?

What is included in the physical exam to evaluate a hammertoe deformity?

Which physical findings are characteristic of hammertoe deformity?

DDX

Which conditions are included in the differential diagnoses of hammertoe deformity?

Workup

What is the role of lab tests in the workup of hammertoe deformity?

What is the role of imaging studies in the workup of hammertoe deformity?

What is the role of histology in the workup of hammertoe deformity?

Treatment

How is a hammertoe deformity treated?

Which medical therapies are used in the treatment of hammertoe deformity?

What is the role of surgery in the treatment of hammertoe deformity?

What is involved in preparation for surgical treatment of a hammertoe deformity?

What is the role of flexor tenotomy in the treatment of a hammertoe deformity?

What is the role of Girdlestone-Taylor flexor-to-extensor tendon transfer in the treatment of a hammertoe deformity?

What is the role of proximal interphalangeal (PIP) joint resection arthroplasty in the treatment of a hammertoe deformity?

Which procedures are performed when PIP joint resection arthroplasty does not correct a hammertoe deformity?

What is included in postoperative care following surgery for hammertoe deformity?

What are the possible complications of hammertoe correction surgery?

What is included in the long-term monitoring of a hammertoe deformity?