Hammertoe Deformity


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 are the main procedures for hammertoe correction.


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. [12]

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.


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-tDiagram 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. [314]

Pathomechanics of hammertoe deformity. Elongated pPathomechanics 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.


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 coMorton 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.


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.


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.

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. 


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 interphalangeaPainful 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 metatarsPhysical 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.

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.

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
  • 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, which is associated with the "crossover" toe 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.

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 hammertHammertoe 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. [6This 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. [7The 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. [8910]

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]

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. [1213 Studies are needed to evaluate its results against those of PIP joint resection arthroplasty. [14Cockup deformity is a frequent complication, especially when significant MTP hyperextension is present preoperatively.

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

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 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. [1617 Although various intramedullary implants have yielded good results, they remain relatively costly. [18]

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.

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. [19]

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. [19]

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. [20In 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. [6A 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). [21 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. [22The 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 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 the patient's treatment are vigilant follow-up care, debridement when necessary, local wound care, and therapy with oral antibiotics to which typical skin flora are sensitive. Knowledge of local community and hospital antibiograms is helpful in guiding empiric therapy. [2324]

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. [25]

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.

Intractable Plantar Keratosis


Intractable plantar keratosis (IPK) is a focused, painful lesion that commonly takes the form of a discrete, focused callus, usually about 1 cm, on the plantar aspect of the forefoot. IPKs are thought to occur in two major forms: discrete and diffuse. [1Typically, they develop beneath one or more lateral metatarsal heads or under another area of pressure. [2345]

Although the diagnosis of IPK is made clinically, the differential diagnosis includes plantar verrucous carcinoma [6and epidermal inclusion cyst. [7 The pain associated with IPK can limit ambulation and also cause compensatory changes in gait.

IPK is often treated successfully with nonoperative care. For those lesions that continue to cause pain after failure of appropriate nonoperative treatment, surgical intervention may be indicated. Various surgical procedures have been described for treatment of IPK, ranging from partial metatarsal excisions to metatarsal osteotomies and shortening procedures or, in the case of the first ray, sesamoid surgery.

Henri DuVries reported on metacondylectomy in 1953. This technique involves removal of a portion of articular surface of the metatarsal and the plantar condyle. The procedure completely resolved the lesion in 79% of patients and was associated with a 93% patient satisfaction rate. [8]

Hatcher et al presented a thorough review of 238 various metatarsal osteotomies used in the correction of IPK. The overall success rate was only 56.5%; this was thought to be due to the fact that transfer lesions occurred in almost 40% of the patients. [9]

Several different distal osteotomies are described, including the dorsal V (or chevron) osteotomy, the tilt-up wedge osteotomy, and the free-floating osteoclasis technique.

The chevron osteotomy of the distal metatarsal, with dorsal displacement of the metatarsal head, is frequently reported. Dreeben et al found complete relief of symptoms in 67% of 45 patients in whom this method was used. [10Young and Hugar likewise used the chevron osteotomy, and they achieved an 87.5% success rate in resolving symptomatic IPK. [11]

A later modification of the DuVries technique is to remove just the plantar condyle, through a dorsal approach. This significantly reduces the chance of transfer lesions, because no change is made to the weightbearing metatarsal parabola.

An isolated IPK beneath the first metatarsal is often caused by a hypertrophic sesamoid bone. Historically, this was treated with tibial or fibular sesamoidectomy. Sesamoid shaving or planing has met with good success and fewer complications. [12 

As with any surgical procedure, not all operative approaches to IPK are 100% successful, and each comes with its own series of complications; thus, the decision to proceed with surgical intervention should be made judiciously. [13]

For patient education materials, see the Foot, Ankle, Knee, and Hip Center.


A plantar or dorsally displaced metatarsal alters the pressure pattern in the forefoot, and an IPK can form in the area of increased pressure. (See the image below.) Typically, this is beneath one of the lesser metatarsal heads and can be exacerbated by a hammertoe deformity or hypertrophic metatarsal condyles. These condyles are small protuberances on the plantar flare of the metatarsal head that serve as a soft-tissue attachment point. In some cases, these condyles become enlarged and cause focused pressure beneath the metatarsal head. [1415]

Plantar aspect of foot with arrow pointing to callPlantar aspect of foot with arrow pointing to callus.

IPKs beneath the great toe are somewhat different. Beneath the first metatarsophalangeal (MTP) joint are two small bones called sesamoids, which are embedded within the soft tissues. The toe flexors pass underneath the first MTP joint, and the sesamoids act as a fulcrum, similar to the patella in the knee. The sesamoids also help to absorb pressure under the foot during standing and walking, and they ease friction in the soft tissues under the toe joint when the big toe moves. Malalignment of or a fracture in the sesamoids can contribute to the development of IPK.

The metatarsal parabola, or cascade, should be assessed when surgical intervention is under consideration. In the typical cascade, the second digit is longer than (or sometimes as long as) the first, followed in length by, from longest to shortest, the third, fourth, and fifth digits. This permits the natural transition of weightbearing forces across the forefoot. If this cascade is altered, either in metatarsal length or in the metatarsal head position in the sagittal plane, this can create an IPK. (See the image below.)

Radiograph shows relatively longer 3rd metatarsal.Radiograph shows relatively longer 3rd metatarsal.


The pathophysiology of IPK involves an impairment of normal weightbearing and a resultant increase in the thickness of the stratum corneum of the sole of the foot. As the lesion develops, the central portion invaginates and can become painful.


A focused area of pressure on the plantar fat pad, typically resulting from a dropped—or, more correctly, plantarflexed—metatarsal, causes IPK. In such cases, the metatarsal head lies in a plane lower than the surrounding metatarsals, focusing exaggerated weightbearing stress on this area. (See the image below.)

IPK under 2nd and 3rd metatarsal heads.IPK under 2nd and 3rd metatarsal heads.

Other causes of IPK include tight or poorly fitting shoes, hammertoe deformity, long lesser metatarsals, hypertrophic plantar metatarsal head condyles, malunion of metatarsal fracture (see the image below), accessory sesamoids, and first-ray hypermobility.

Radiograph shows malunited 4th metatarsal neck fraRadiograph shows malunited 4th metatarsal neck fracture and relatively longer 2nd and 3rd metatarsals.

In poorly fitting shoes, the toes may become buckled in a tight toe box and create a retrograde hammertoe effect. This forces the toe on top of the lesser metatarsal head and drives the head down against the plantar fat pad. Long lesser metatarsals also have added weightbearing stress shifted to them, and this shift can cause an IPK. A hypermobile first ray shifts weightbearing stress laterally and potentially overloads the plantar fat pad.

An IPK beneath the first metatarsal head is often caused by hypertrophy of either the fibular or tibial sesamoid. Other possible causes include a plantarflexed first ray, a hammered great toe, a cavus foot deformity, or excessive pronation.

Plantar keratosis can be linked to obesity and diabetes; the association was found in about 10% of patients studied in a series of 109 patients in Spain. [16]


IPK is not uncommon, but its exact frequency remains to be defined.


A successful outcome is based on accurately identifying the etiology of the IPK and clearly establishing realistic expectations. If the underlying cause is not addressed, the outcome will be poor and the patient unhappy.

Conservative, nonoperative treatments should not be discounted: Often, they are all that is required for patient relief. A study by Kang et al found that the use of metatarsal offloading pads reduced peak pressures and improved subjective pain responses in patients. [17]

Mann and Wapner reported on tibial sesamoid shaving in 10 patients with symptomatic IPK below the first metatarsal. At an average follow-up of 52.6 months, nine of the 10 patients reported good to excellent results, and one described results as fair. [12]

For the more typical lesser-metatarsal IPK, one of the various metatarsal procedures may be used. The difficulty with the majority of the metatarsal osteotomies is the unpredictable degree of dorsal displacement. Intraoperatively, it is difficult to accurately gauge the level of the metatarsal heads in the sagittal plane. The use of internal fixation reduces the chance that weightbearing will cause unwanted dorsal displacement.

Kiviniemi et al treated 25 plantar callosities in 13 patients (mean age, 48 years; five male, eight female) with transverse distal metatarsal osteotomy. Osteotomies united primarily in 24 cases and in one after revision. Twenty-three of the callosities healed, two of them after an oblique repeat osteotomy; follow-up extended 7 years. In four of the treated feet, eight hammertoe deformities developed in the involved rays. In five of the feet, eight plantar callosities developed outside the operated rays. [18]

The distal chevron is reported in multiple studies. Kitaoka and Patzer reviewed 21 feet that had undergone chevron osteotomy on the lesser metatarsals; the mean follow-up period was 4 years. Sixteen feet were labeled as good, two as fair, and three as poor. Transfer metatarsalgia occurred in three feet (14%). [19]

Idusuyi et al found that although the single oblique lesser-metatarsal osteotomy may be successful, 50% of the patients studied continued to have some degree of pain, and most patients had limitations in footwear. [20]

A study by Grimes and Coughlin on the Weil osteotomy concluded that a proximal shift of the distal osteotomy may also shift in a plantar direction. They recommended that if a shift of more than 5 mm is needed, a 2-mm-thick blade be used to allow for some dorsal displacement, in order to prevent plantar pressures. [21]

Another study on the clinical results of the Weil osteotomy found relief of plantar pain in 97% of patients treated, at a follow-up of 26 months. [22]

Proximal metatarsal segmental resection involves resection of a cylindrical segment of proximal metatarsal bone approximately 0.5 cm long. Spence et al reported good results in 54 patients operated on with this procedure. [23]

Overall, surgical intervention for lesser-metatarsal IPK should be undertaken with caution. Pontious et al reviewed 29 patients who altogether had undergone 40 V-shaped osteotomies for IPK. The overall effectiveness was quite limited, and there were multiple complications. More than 42% of the patients developed transfer lesions, 10% had recurrence, and 25% reported lack of toe purchase. 


The patient with intractable plantar keratosis (IPK) reports pain in the plantar aspect of the forefoot, which is aggravated by weightbearing. Pain is exacerbated when the individual is barefoot; for instance, Thai monks who walk barefoot have more foot problems (including IPK) than those who work with shoes. [25 Patients often report a sensation similar to walking on a marble. Most have had this lesion for many years and have tried various home remedies. Sometimes, patients provide a confusing history of a possible foreign-body lesion or of having warts.

Physical Examination

On physical examination, the IPK typically appears in one of two presentations. A focused, discrete IPK is the more common presentation and is seen directly overlying a bony prominence. This lesion is approximately 1 cm, with a hyperkeratotic rim and a painful, white center core. There is rarely any erythema, edema, or suspicion of infection. This lesion occurs as an isolated IPK or as several discrete, isolated IPKs.

The other, less common presentation is a more diffuse buildup of keratotic tissue, called a diffuse IPK or tyloma. This frequently is seen spanning across the plantar aspect of several metatarsal heads and does not have the focused central core. Cysts can arise in IPK or can even cause [5 other related conditions, such as plantar fasciitis.

Laboratory Studies

Standard preoperative tests are indicated.

Pedobarography provides numeric information regarding dynamic and static foot pressure. However, one study found the diagnostic validity of pedobarography to be low for intractable plantar keratosis (IPK) related to metatarsophalangeal (MTP) dislocation in rheumatoid arthritis. [27]

Imaging Studies

Weightbearing radiography should be performed for IPK. Anteroposterior (AP), lateral (LAT), and forefoot axial (FtAx) projections are best. Images are reviewed for possible fractures, metatarsal avascular necrosis (AVN), or accessory sesamoids. The metatarsal parabola should be noted, as well as the sagittal plane of the metatarsal heads on the FtAx view.

A radiopaque marker can be used to indicate the exact location of the lesion in the soft tissue.

If the lesion is overlying the first MTP sesamoids, the FtAx view is useful for evaluating for fracture of the sesamoid, as well as for gauging the overall size of the sesamoid.

A Harris mat can be used to determine pressure areas.

Other Tests

Nerve conduction studies, electromyography (EMG), and noninvasive vascular testing may be used if indicated on the basis of the clinical history. However, these tests are rarely indicated in the workup of IPK.

Histologic Findings

Analysis of a biopsy specimen of IPK will show hyperkeratosis and inflammation.

Approach Considerations

Detailed history, meticulous clinical assessment, and radiographic evaluation should be used to assess the causes and extent of intractable plantar keratosis (IPK). Lesions recalcitrant to nonoperative care and routine debridement can be considered for surgery.

Indications for surgical treatment of IPK include the following:

  • Failure of periodic debridement, padding, and accommodative shoes
  • Continued pain and loss of function that a patient cannot tolerate
  • Patient acceptance of the risks and benefits of surgery

Absolute contraindications for surgical correction of an IPK include the following:

  • Local infection
  • Vascular insufficiency
  • Painless lesion
  • Neuropathy

Relative contraindications include the following:

The future of IPK treatment must focus on more accurate identification of the underlying pathology of IPK. The enhancement of nonsurgical means of treatment and the refinement of surgical options also are critical. Computerized force plates can aid in understanding the pressure distribution on the foot and thus create better offloading orthotics.

The high rate of transfer metatarsalgia and recurrence of IPK suggests that surgical intervention should be undertaken with caution. Surgery is more successful when a specific etiology can be determined. Performing prophylactic surgery on an asymptomatic foot because of irregularities seen on radiography is highly controversial and is not recommended.

In a study by Zhao et al, pelvis adjustment combined with Dong's extraordinary points helped abate 21 cases of refractory calcaneal pain, and it may have the potential to help treat IPK. [28]

Medical Therapy

First-line medical treatment of IPK includes the following:

  • Padding - A doughnut-type cutout pad can be placed directly over the lesion; this allows the IPK to sit in the center and be offloaded by the surrounding pad
  • Shoe modifications - A low-heel shoe reduces the amount of weight shifted toward the forefoot and can be more forgiving on the foot; a shoe with a wide, soft toe box that does not crowd the toes is also recommended
  • Oral nonsteroidal anti-inflammatory drugs (NSAIDs) - These are occasionally used but typically are not very effective
  • Injectable therapies - Steroid injection into or around an IPK is not recommended, on the grounds that it can create fat-pad atrophy and further exacerbate the plantar foot pain; other injectable modalities have been tried, but results to date have not been promising [29]
  • Orthotic devices - These are typically accommodative or offloading and are soft so as to help cushion the area; if the IPK is secondary to a hypermobile first ray, a rigid Morton extension may be used to help focus more of the weightbearing force onto the medial column of the foot
  • Moisturizing lotions or creams - These can be effective in softening the keratosis and reducing pain; some prescription creams include mild lactic acid to help remove callus tissue
  • Pumice stones and callus removers - These should be used with caution in certain patients; they are typically used in the shower or bath, when the skin is soft; reducing the overall mass of the lesion usually provides some symptomatic relief
  • Foot baths
  • Scrub brushes
  • Paraffin baths to reduce callus buildup
  • Botulinum toxin - This may be a treatment for IPK [30]

More effective and invasive treatments include debridement. In a study by Jain et al, platelet-rich plasma injections were more effective than corticosteroid injections for the treatment of plantar fasciitis; such injections might work for IPK. [31]

Surgical Therapy

Surgical options

Surgical treatment of IPK can involve the following:

  • Paring of callus tissue and removal of the central core of the lesion
  • Sesamoid planing, with protection of the flexor attachments - This is done in lesions below the first metatarsal
  • Complete tibial or fibular first-ray sesamoidectomy - This is avoided if possible, but it may be necessary in cases of an enlarged sesamoid, sesamoid arthrosis, or nonunion of fracture; care should be taken to reestablish soft-tissue balance of the first metatarsophalangeal (MTP) joint so as to prevent a varus or valgus plane deformity
  • Distal metatarsal osteotomies - Variations include minimal incision or percutaneous transverse osteotomy of the metatarsal neck, chevron osteotomy, oblique sliding osteotomy, dorsal closing wedge, partial or total resection of the metatarsal head, intramedullary decompression, and lesser-rays condylectomy at osteotomy [8; in the past, most of these osteotomies were not fixated, but the current norm is to use internal fixation, employing either screws or wires, with possible percutaneous wiring as well [3233]
  • Proximal metatarsal segmental resection - This involves removal of the proximal metatarsal bones to shorten the overall length of the metatarsal and translate the head more proximally

Data have been published on the clinical outcomes of isolated periarticular osteotomies involving the first metatarsal to treat hallux rigidus. [34]

Preparation for surgery

Patients should be appropriately counseled on the risks and benefits of surgery and the expected postoperative course. Operative risks include infection, neurovascular damage, nonunion, wound dehiscence, toe destabilization, recurrence of lesion, and development of a transfer lesion. The patient should be made aware of the likelihood of recurrence or transfer lesion development. The patient must have appropriate expectations. An informed surgical consent is obtained.

The clinician must determine the cause of the IPK because this dictates the surgical correction. Associated pathologies, such as hammertoe contracture, should be addressed at the same sitting if they are causative to the painful IPK.

Operative details

There are various surgical approaches to the correction of an IPK. The authors' preferred technique includes either a plantar condylectomy of the metatarsal head or a double-cut Weil oblique osteotomy of the metatarsal head. Either approach is well suited to monitored anesthesia care (MAC) with a regional popliteal or ankle block. An ankle Esmarch or tourniquet can be used, provided that this does not cause contracture of the long toe flexors.

A dorsally based linear incision is marked just medial or lateral to the extensor tendon over the involved MTP joint. Sharp dissection through the skin and fascia tissue is performed, with care taken to protect any cutaneous nerves. The incision is deepened, and the extensor complex is elevated and protected either medially or laterally. The capsular tissue is sharply incised, and minimal release of the collaterals is performed to enhance exposure. The involved toe is plantarflexed to expose the metatarsal head.

If a plantar condylectomy is to be performed, the plantar capsular attachments must be released with a blade. Care should be taken to protect the long flexor tendons beneath the metatarsal head. The plantar condyles are identified, and one is typically larger than the other. A microsagittal saw is used to remove the condyles in a thin plantar osteotomy made parallel to the weightbearing surface (plantar one-third of the metatarsal head).

The small sliver of bone, including the condyles, is then removed. A hand rasp can be used to smooth any rough edges. A percutaneous Kirschner wire (K-wire) is driven through the length of the toe and across the involved MTP joint down the metatarsal. This is important for allowing the plantar capsule to adhere to the cut bone surface and preventing MTP destabilization.

If the involved metatarsal is plantarflexed or elongated, a double-cut Weil osteotomy is instead performed. The microsagittal saw is used to make a 30° osteotomy at the superior aspect of the metatarsal head-neck junction angled from distal-dorsal to proximal-plantar. Two blades are stacked together to create a controlled wedge resection. The width of each blade cut is approximately 1 mm; thus, two blades together create a 2-mm wedge. This allows some dorsal displacement of the metatarsal head in a controlled fashion.

The metatarsal head is also translated slightly proximal along the osteotomy to shift the head away from the pressure area, and it is fixated with a small screw. An aggressive proximal shift must not be made, because this can shift the head in a plantar direction as it follows the angle of the osteotomy. Again, a percutaneous K-wire is used to splint the toe and maintain alignment of the MTP joint.

The extensor tendon sling and capsular tissue are repaired with 2-0 absorbable suture. Subcutaneous closure is performed with 2-0 absorbable suture, and the skin is closed with 4-0 nonabsorbable suture of choice. The IPK is then debrided from the plantar forefoot, and the central core should be completely removed.

A compressive dressing is applied, and the tourniquet is released. Before leaving the operating room, the physician should confirm that the toe's vascularity is intact.

Postoperative Care

The patient is placed in a rigid postoperative shoe and allowed to bear weight on the heel to tolerance. The dressing is kept clean and dry and is changed in 7-10 days. At that point, the sutures are removed if adequate healing has taken place. Postoperative radiography is performed to confirm alignment of the toe and/or osteotomy.

The patient must remain in the postoperative shoe until the K-wire is removed and adequate healing of the osteotomy is observed. Typically, the K-wire is left in place for 4 weeks and then removed in the office.

At 6 weeks postoperatively, follow-up radiography is performed to assess the healing of the osteotomy. The osteotomy typically requires 6-8 weeks to heal enough to allow migration out of the surgical shoe and into a comfort shoe. Once the patient is in a comfort shoe, postoperative exercises of the toe are encouraged, to restrengthen the toe and prevent loss of purchase, or floating, of the toe.

Typically, patients are able to return to all activities without restriction by 12 weeks.


Postoperative complications of surgical therapy for IPK include the following:

  • Edema
  • Recurrence of IPK
  • Pain
  • Numbness
  • Stiffness of the involved MTP joint
  • Shortening of digits or metatarsals
  • Malposition
  • Nonunion
  • Delayed union
  • Transfer lesions
  • Vascular complications

Long-Term Monitoring

Appropriate shoe wear is important in preventing recurrence of the IPK. The patient should again be counseled on wearing shoes with enough room in the toe box and a reasonable heel height. Custom orthotics may be beneficial in supporting the foot, and specific modifications can be made to off-load the surgical area.

Periodic follow-up should be made to monitor for recurrence of the IPK or development of transfer lesions.

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