FOOT & ANKLE INTERNATIONAL Copyright 2008 by the American Orthopaedic Foot & Ankle Society DOI: 10.3113/FAI.2008.0000 Current Concept Review: Metatarsalgia Norman Espinosa, MD; Ernesto Maceira, MD; Mark S. Myerson, MD Zurich, Switzerland INTRODUCTION forefoot and the etiology of central metatarsalgia we refer to the “rocker concept” which originates from gait analysis.34 The “first-rocker” (0% to 10% of the cycle) includes the period between heel strike and initial ground contact of the forefoot; it is controlled by the ankle dorsiflexors and allows the tibia to rotate in relation to the calcaneal tuberosity. Once foot flat is achieved, the tibia glides over the talus.26,27 This period, the midstance or “second-rocker” (10% to 30%), is controlled by eccentric contraction of the gastrocsoleus. Increased loading of one or more metatarsal heads during the midstance phase of gait is a common cause of metatarsagia. This situation can occur when there is increased plantarflexion of one or more metatarsals leading to localized forefoot overload and resulting in increased pressure at the corresponding metatarsophalangeal (MTP) joints. The “third-rocker” (30% to 60% of the cycle) starts with heel rise and is initially controlled by gastrocsoleus muscle activity. “Third-rocker” (or propulsive metatarsalgia) may occur during heel rise and is linked to metatarsal length. Metatarsals that are disproportionately long will subject the corresponding metatarsal head and surrounding soft-tissues to more repetitive loading. Metatarsalgia refers to localized or generalized forefoot pain in the region of the metatarsal heads.10 The term is frequently used as a “waste-basket” diagnosis for forefoot pain. Often this pain is plantar, beneath the metatarsal heads, and arises from either mechanical or iatrogenic causes.45 The surgical treatment of metatarsalgia remains controversial, with multiple procedures described in the literature.5,14,20,21,48 A thorough understanding of the biomechanics of the forefoot and the underlying pathology of the particular type of metatarsalgia affecting the patient is a prerequisite to selecting the proper treatment. This review focuses on central metatarsalgia, defined as pathology involving the second through fourth metatarsals. It will provide a basic understanding and classification of central metatarsalgia, and discuss the options for the successful management of this challenging clinical entity. BIOMECHANICAL CONCEPTS AND CLINICAL IMPLICATIONS A fundamental etiological component of metatarsalgia is the repetitive loading of a locally concentrated force in the forefoot during gait. An overload of weightbearing forces may affect the entire forefoot or an isolated area (e.g., a metatarsal head) when the foot is plantigrade. During the stance phase of gait, the plantigrade foot provides stable support, while the leg moves over it to propel the body forward. In order to understand the mechanics of gait in the No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Corresponding Author: Norman Espinosa, MD Department of Orthopaedics University of Zurich Balgrist Forchstrasse 340 8008 Zurich Switzerland E-mail: [email protected] For information on prices and availability of reprints, call 410-494-4994 x226 Norman Espinosa, MD 871 872 ESPINOSA ET AL. Foot & Ankle International/Vol. 29, No. 8/August 2008 Table 1: Level of evidence and grades of recommendation Level of Evidence — Level I: high quality prospective randomized clinical trial — Level II: prospective comparative study — Level III: retrospective case control study — Level IV: case series — Level V: expert opinion Grades of Recommendation (given to various treatment options based on Level of Evidence supporting that treatment) — Grade A treatment options are supported by strong evidence (consistent with Level I or II studies) — Grade B treatment options are supported by fair evidence (consistent with Level III or IV studies) — Grade C treatment options are supported by either conflicting or poor quality evidence (Level IV studies) — Grade I when insufficient evidence exists to make a recommendation CLASSIFICATION AND CLINICAL PRESENTATION In order to appreciate the rationale behind the various treatment options, a framework differentiating metatarsalgia based on etiology is crucial. Table 2 divides metatarsalgia into three categories and lists the various conditions associated with each subtype. Primary metatarsalgia Primary metatarsalgia refers to symptoms arising from innate abnormalities in the patient’s anatomy leading to overload of the affected metatarsal. These anomalies may include a disproportionately long or plantarflexed metatarsal relative to the remaining rays of the forefoot.14,15,41,52 Discrepancies in metatarsal length contribute to primary metatarsalgia, with a long second metatarsal being the most frequent anomaly. Patients with primary metatarsalgia often present with pain during the propulsive phase of gait (“thirdrocker” metatarsalgia). The pain is localized underneath the prominent metatarsal head. The plantar soft tissue can be swollen and inflamed. With continuing pressure at this locus, the overlying skin will react and establish an intractable plantar keratosis (IPK). Table 2: Synopsis of the different types of metatarsalgia METATARSALGIA PRIMARY METATARSALGIA Insufficiency of the first ray Excess of metatarsal plantar slope or plantarflexed metatarsal bone Metatarsal head protuberance Arthritis, Tumor, Infection, Congenital, Hereditary Metatarsal length discrepancy Equinus Pes cavus, Contracture of gastroc-soleus complex SECONDARY METATARSALGIA Metabolic disorders Gout Systemic disorders Rheumatoid arthritis Arthritides of MP joints Trauma Neurological disorders Morton’s neuroma, Tarsal tunnel syndrome Freiberg’s disease IATROGENIC METATARSALGIA Failed hallux valgus surgery Failed MP-I fusion Failed corrective metatarsal osteotomies (indication vs. technical error) Failed shortening of 2nd ray Foot & Ankle International/Vol. 29, No. 8/August 2008 Primary metatarsalgia can also result from a plantarflexed metatarsal.13 Plantarflexion of a central metatarsal may occur as a result of a malunited fracture or due to a severe hammertoe deformity. Patients may report pain during the stance phase of gait (“second-rocker” metatarsalgia). A distinguishing feature of second-rocker keratoses is their strictly plantar location in relation to the corresponding head. A well-localized IPK directly beneath the head (with no distal extension towards the toe) may occur when only one metatarsal is plantarflexed. When multiple metatarsals are plantarflexed, several discrete keratoses appear. In thirdrocker metatarsalgia, the keratoses are not located directly beneath the metatarsal, but instead plantar and distal to the affected heads. External rotation of the limb at final stance creates a shear effect that manifests as a rounded appearance of the keratosis that usually spans several heads. The result most often is a large and diffuse area of hyperkeratosis, which extends distally toward the toes. Keratoses associated with first ray insufficiency syndromes (i.e., hallux valgus, short first metatarsal) exhibit third-rocker features, but in cases of concomitant MTP joint subluxation, a second-rocker lesion appears as well within the previous contour of the thirdrocker keratosis. Other causes of primary metatarsalgia include an abnormally enlarged metatarsal head or condyle. This deformity occurs infrequently and may result from infection, tumor, congenital malformation or other hereditary factors. Forefoot equinus, as seen in a cavus foot, or posterior equinus,13,40 (e.g., contracture of the gastrocsoleus complex) may also cause primary metatarsalgia. Of note, a gastrocsoleus contracture is another cause of a diffuse IPK spanning more than one metatarsal head. Secondary metatarsalgia Systemic conditions that can lead to secondary metatarsalgia include trauma,28 inflammatory arthropathy, gout,6,20 arthritides and instability of the MTP joints,13,50 Morton’s neuroma,11,36 tarsal tunnel syndrome48 and Freiberg’s infraction.13 Not all of these conditions directly affect the metatarsal, and instead indirectly overload the forefoot. Trauma may shorten, elevate or plantarflex a metatarsal fracture and cause pain, but an associated dislocation of the MTP joint or periarticular soft tissue injury may contribute to pain. The effect of metabolic disorders such as gout or rheumatoid arthritis may cause the MTP joint to hyperextend, resulting in a shift of plantar pressure to the metatarsal heads. This shift of plantar pressure combined with distal migration of the plantar fat pad may lead to pain. Atrophy of the fat pad secondary to a systemic condition may also cause central metatarsalgia. The same forces that overload the metatarsal head and surrounding soft-tissues can also injure the plantar digital nerve and result in pain similar to mechanical metatarsalgia. METATARSALGIA 873 Iatrogenic metatarsalgia Iatrogenic metatarsalgia can be troublesome and is more prevalent than previously thought.12,45 This type of central metatarsalgia may arise from malalignment of metatarsal osteotomies or from a metatarsal head resection. Nonunion or delayed union of a metatarsal after reconstructive surgery or errors in positioning or fixation of the osteotomy can all lead to transfer of the forces of weightbearing and overload of the adjacent metatarsals. One of the most common errors is the iatrogenic shortening of the second metatarsal because of nonunion, fracture or incorrect choice of lesser metatarsal osteotomy. Elevation of the ray may lead to third-rocker metatarsalgia, while shortening it may lead to second-rocker metatarsalgia. Sometimes metatarsal heads are only partially resected, leaving remaining bone spurs that lead to punctiform peak pressures under the skin. The same problem is encountered if the phalangeal base is improperly removed. Finally, hallux valgus surgery that results in elevation of the first ray can cause a shift of plantar pressures to the lesser metatarsals. CLINICAL AND RADIOGRAPHIC EVALUATION The patient’s foot should always be evaluated while standing. This helps demonstrate the magnitude of any deformity. Inspection of the plantar aspect of the foot may reveal either localized or diffuse patterns of hyperkeratosis. The toes are examined and the range of motion documented, along with plantarflexion and dorsiflexion of the ankle joint to assess contractures of the extensor or flexor tendons. Gastrocnemius or gastrocsoleus contracture is tested according to the method described by Silfverskj¨old.53 Palpation of each MTP joint and intermetatarsal web space is essential. Clawtoes with synovitis or even subluxation of the MTP joints is a common finding. The neurovascular status should be carefully evaluated with specific focus placed on the microcirculation of the lesser toes. Palpation of the metatarsal heads and the plantar condyles is often possible, but is easier in advanced stages of disease when the plantar fat pad is displaced distally.39 Gait analysis can be helpful in determining the type of metatarsalgia pattern and to detect the regions of overload.34 Standard weightbearing foot radiographs including an anteroposterior, internal oblique and lateral view are sufficient to evaluate the forefoot.37 The relative length of each metatarsal and the overall metatarsal cascade should be evaluated.37,67 On the lateral view, the declination of the metatarsals can be assessed. Meanwhile, the internal oblique view allows for better visualization of subluxed or dislocated MTP joints. In rare cases, with an occult entity underlying the metatarsalgia, magnetic resonance imaging (MRI) can aid in establishing the correct diagnosis. 874 ESPINOSA ET AL. TREATMENT The treatment of central metatarsalgia should address the underlying pathology, as well as the expectations, of the patient. Conservative treatment should always be maximized before considering surgery in the management of this condition. Conservative treatment Not much scientific literature exists to confirm the effectiveness of conservative treatment for the treatment of central metatarsalgia. Nevertheless, such measures often meet with success and have the additional benefit of not compromising future treatment. Conservative treatment may include stretching exercises, shoe modification, shaving of the callosity, rest, use of metatarsal pads and molded insoles, corticosteroid injections, and anti-inflammatory medications. Stretching exercises Stretching exercises in patients suffering from gastrocnemius or gastrocnemius-soleus tightness are intended to lengthen the triceps surae muscles and thereby decrease the pressure at the forefoot. These exercises are best performed by the patient after education by a physical therapist.12 Gajdosic and coworkers demonstrated that a 6week stretching program increased the maximal ankle dorsiflexion angle and length extensibility, as well as the passive resistive properties throughout the full stretch range of motion. They further demonstrated that stretching enhances the dynamic passive length and passive resistive properties (Level I study).16 However, this study did not examine patients with central metatarsalgia. Thus insufficient data exists to render a proper recommendation for its use in central metatarsalgia (Grade I recommendation). Shoe modifications and padding The goal of shoe modification is to distribute pressure more evenly over the forefoot and among the metatarsal heads. The shoe should be comfortable and fit correctly. Wider toe boxes can resolve pain in patients suffering from lesser toe deformities, MP joint instability, hard and soft corns.10 Stretching the shoebox overlying the fifth metatarsal head can help to reduce pain in patients with bunionette deformites. Lower heel height, an excavated insole, external metatarsal bar, and a rocker-bottom sole can help improve symptoms in many patients with central metatarsalgia. Generally, accommodative insoles may redistribute pressure under the foot while functional orthoses are intended to control abnormal intersegmental motion; both of them may be useful in the non-operative management of metatarsalgia.4,28,29,31,47 The same spectrum of applications pertains to the use of orthotic arch supports,15,18,55 which includes padding of the insole just proximal to the painful metatarsal head.23,65 Foot & Ankle International/Vol. 29, No. 8/August 2008 This padding serves to distribute force away from a prominent metatarsal head. Experimental studies support their effect in decreasing pressure underneath the metatarsal heads.7,23 Conservative treatment may be successful if capsulitis and instability are diagnosed early. In a prospective study performed by Kang et al., 13 patients (18 feet) with secondary metatarsalgia were investigated regarding the use of metatarsal pads. The group found that the successful decline in the pressure time integral and maximum peak pressures under the second metatarsal head after metatarsal pad application was correlated to subjective pain improvement (Level II evidence). Based on the evidence provided from these Level III and IV studies, a Grade B recommendation applies to the use of shoe modification and padding for central metatarsalgia. Shaving of callosities Although the trimming of a plantar callus may reduce the thickness and thereby reduce the pressure over a painful IPK, no evidence-based information exists about the effect of shaving calluses for the treatment of metatarsalgia. A high rate of recurrence of the callosity exists because it does not address the underlying pathology. Thus, only a Grade I recommendation can be assigned. Surgical treatment If non-operative treatment is unsuccessful, surgical treatment may be warranted. The primary goal of surgery is to restore a normal distribution of pressure within the forefoot. As a rule, it is important to restore a harmonic Maestro curve,37 to restore the correct metatarsal slope, and to provide adequate ground contact for the metatarsal heads. It is also important to understand the effect of metatarsal osteotomies on forefoot biomechanics to avoid possible complications. A variety of surgical treatments for metatarsalgia have been described. They include plantar condylectomy, distal oblique metatarsal osteotomy, diaphysieal metatarsal osteotomy, flexor to extensor transfer for the management of lesser MTP joint instability, and metatarsal head resection. Plantar condylectomy Plantar condylectomy of the metatarsal is rarely indicated for central metatarsalgia. It may be considered for the treatment of well-localized IPKs. A major disadvantage of a plantar condylectomy is the possibility of destabilizing the plantar plate. The loss of capsuloligamentous restraint may lead to iatrogenic instability and arthritis of the MTP joint. Condylectomy is not indicated for larger IPKs: a distal metatarsal osteotomy may be the more logical approach.9,51 Conklin performed a retrospective review of 86 basal hemiphalangectomies in 52 patients (Level IV evidence).41 In his series 60% of the patients had total relief of pain; however, 29% were classified as dissatisfied. An extensor tenotomy increased the satisfaction rate and was found to decrease the radiographic sagittal angulation of the Foot & Ankle International/Vol. 29, No. 8/August 2008 toe. The current body of evidence is insufficient (Grade I recommendation) to support to use of plantar condylectomy for central metatarsalgia. Distal oblique metatarsal osteotomy Distal metatarsal osteotomies, such as the Weil and the Maceira triple osteotomies are designed to restore the physiologic cascade of the lesser metatarsals and evenly redistribute the forces of weightbearing at the forefoot. These osteotomies reposition the metatarsal head through shortening, elevation or both.3,22,33,35 The Weil osteotomy provides a longitudinal decompression and is particularly relevant in patients suffering from metatarsalgia due to an excessively long metatarsal. The main problem associated with the original design of the Weil osteotomy is plantar translation of the metatarsal head during shortening. This translation can lead to transfer metatarsalgia, dorsiflexion contracture of the MTP joint, and persistent pain. Modifications of the Weil osteotomy have been introduced in order to prevent excessive shortening of the metatarsal and concomitant plantarflexion of the head. Melamed et al. found that modifying the Weil osteotomy by adding a dorsal oblique bone wedge resection resulted in moderate shortening and essentially no plantar displacement of the head.63 Additionally, they found that removal of each 1 mm of dorsally based wedge resulted in 0.5 mm of shortening and 0.6 mm of elevation and that the amount of shortening depended also on the angulation of the osteotomy. Based on those results, Maceira and coworkers introduced the so-called “triple-osteotomy”.35 This modified osteotomy affords precise and accurate shortening of the metatarsal without unwanted plantar translation of the heads. The triple osteotomy also preserves the relationship between the dorsal interossei and transverse axis of rotation of the MTP joint to avoid an extension deformity. An alternative method to elevate the head during shortening is to use a double layer Weil-osteotomy.1,30 Results and complications Hofstatter et al.22 performed a prospective study and evaluated the short- to long-term results of the Weil osteotomy for the treatment of metatarsalgia with subluxated or dislocated lesser MTP joints in 25 feet (Level II evidence). Good to excellent results were achieved in 88% of cases at a followup of 7 years. The AOFAS score significantly improved from 48 to 83. The authors found that the procedure significantly reduced pain, diminished isolated plantar callus formation and increased walking capacity. Recurrent dislocation of the metatarsophalangeal joint was seen in 12% of cases. The authors concluded that although floating toes and restricted movement of the metatarsophalangeal joint may occur, the Weil osteotomy was safe and effective. Retrospective reviews by Beech et al.,3 Vandeputte,66 and Trnka et al. (Level IV evidence)59 also identified good to excellent results in most patients undergoing a Weil osteotomy. METATARSALGIA 875 A pitfall of the Weil osteotomy is the difficulty of obtaining the correct amount of shortening of the metatarsal. Insufficient shortening leads to persistent pain and excessive shortening causes transfer metatarsalgia in the adjacent metatarsals. Stiffness of the MTP joint is another potential problem associated with a Weil osteotomy. This drawback predominately occurs at the second MTP joint. Non-union and malunion, although infrequent, may also occur with this procedure.42,45 A floating toe, defined as a toe that does not contact the ground, is a postoperative complication that can severely compromise the effectiveness of a distal metatarsal osteotomy. According to Migues et al., the incidence of a floating toe following Weil osteotomies may be as high as 28.5%. If proximal interphalangeal joint arthrodesis is performed concurrently with the osteotomy, the rate increases to 50%.42 Excessive plantar translation of the distal fragment has been identified as a causative factor because it shifts the center of rotation of the MTP joint plantarwards.63 This change reverses the effect of the interossei muscles and they become dorsiflexors instead of plantarflexors of the MTP joint. Methods proposed to minimize the occurrence of a floating toe include lengthening the extensor tendon, performing the osteotomy parallel to the ground combined with the dorsal wedge resection technique, adding a flexorto-extensor transfer, and inserting a Kirschner-wire across the joint.60,63 A recent cadaveric study performed by Khalafi et al.33 evaluated plantar pressure changes associated with Weil osteotomy of the second metatarsal neck. They were observed an average decrease in pressure beneath the second metatarsal from 70.6 to 45.1 kPa in neutral and 813.0 to 281.4 kPa in heel rise, representing statistically significant decreases of 36% and 65%, respectively. The authors concluded that the Weil osteotomy effectively offloads the second metatarsal head at neutral and heel rise positions. Despite the challenges associated with the Weil osteotomy, this procedure has provided effective pain relief in the management of metatarsalgia in several retrospective series. The evidence supports a Grade B recommendation for the use of distal metatarsal osteotomies in the management of central metatarsalgia. Diaphyseal metatarsal osteotomy A diaphyseal osteotomy has also been endorsed as a viable treatment for central metatarsalgia associated with a long metatarsal. Helal19 introduced an osteotomy of the midshaft of the metatarsal similar to the Meisenbach osteotomy. The difference between the two procedures lies in the orientation of the osteotomy. Helal proposed a more obliquely directed cut from dorsal-proximal to plantar-distal. Helal emphasized the importance of preserving the medial and lateral tubercles. These tubercles are the points of attachment for the collateral and the plantar ligaments and stabilize the distal fragment after the osteotomy. The original description of the Helal 876 ESPINOSA ET AL. osteotomy did not include internal fixation, and subsequently the distal fragment shifted and proximal translation of the distal fragment was observed when the patient stood on the foot. The location of the osteotomy in diaphyseal bone is associated with an increased risk of delayed union and nonunion.12,62 Although modifications of the original procedure have been introduced by Mann and DuVries, and Turan and Lindgren,64 the overall results of a diaphyseal osteotomy have not improved substantially. Results and complications Helal retrospectively reviewed 47 feet in 38 patients treated with his osteotomy (Level IV evidence).19 He reported mixed results. Six patients continued to experience restriction in walking while five patients had postoperative complications that included infection, nonunion and stiffness. Winkler68 retrospectively reviewed a large series of 336 Helal osteotomies in 114 patients (Level IV Evidence). Seventytwo percent of patients reported good relief of their pain. When the authors evaluated their failures with pedobarographic measurements, the majority were due to an unequal distribution of weight in the forefoot. Two patterns of incorrect weightbearing were recognized: excessive weightbearing on the untreated adjacent metatarsals, and diffuse overload of the entire forefoot secondary to loss of weightbearing support caused by contracted MTP joints. Similar results were reported by Slavik and Kubice (Level IV evidence).54 Trnka and colleagues61,62 concluded that the Helal osteotomy is not an acceptable procedure for correcting metatarsalgia caused by dislocation of the MTP joint and that a Weil osteotomy should be performed in such a case. This retrospective study compared the outcomes of 30 patients treated with either the Weil or Helal osteotomy for metatarsalgia resulting from dislocation of one or more lesser MTP joints (Level III evidence). The authors found a 30% rate of malunion and a 14% rate of nonunion in patients treated with Helal osteotomies. Retrospective reviews by Pedowitz,46 Winson,69 and Idusuyi25 each identified unacceptably high rates of complication with the use of the Helal osteotomy. Pedowitz concluded that this osteotomy should not be used for an IPK associated with fixed toe deformity.46 Winson et al.69 investigated the outcome of 124 feet. Almost 50% had a metatarsal head prominence or symptomatic callus postoperatively. Additionally, 30% suffered from transfer-type lesions with callosities under adjacent metatarsal heads. Similarly, in the study of Idusuyi et al.25 half of the patient population continued having pain 10 years after Helal osteotomy. Multiple retrospective studies (Level III evidence) have reported that patients who undergo a Weil osteotomy for treatment of overload metatarsalgia have a substantially higher satisfaction, lower incidence of recurrent metatarsalgia, and fewer transfer lesions than those treated with a Helal osteotomy.25,62,54,68,61,46,69 Furthermore, those managed with the Weil osteotomy had a higher percentage Foot & Ankle International/Vol. 29, No. 8/August 2008 of radiographic reduction and maintenance of correction of their MTP joint dislocation than those managed with the Helal osteotomy. Overall, this body of evidence is insufficient to support the use of the Helal osteotomy for patients with metatarsalgia and constitutes fair evidence (Grade B recommendation) to support preference for the Weil osteotomy over the Helal osteotomy. Metatarsal head resection Although most surgeons have abandoned this procedure, it continues to be employed in cases of severe metatarsalgia caused by underlying rheumatoid arthritis, elderly patients with low physical demands,2,32,38 and following severe iatrogenic forefoot deformity where limited options for salvage exist. Retrospective studies assessing patients with advanced MTP joint destruction secondary to rheumatoid arthritis show a benefit from metatarsal head resection (Level IV evidence)24,43,56 . The drawbacks associated with metatarsal head resection is the potential for transfer lesions to develop beneath the adjacent metatarsals, cosmetic disturbances, dorsal contracture of the toes, as well as instability or floppiness of the forefoot. Isolated resection of the fifth metatarsal head may be considered in the case of a severely painful bunionette deformity, but should be avoided in patients with heel varus. Metatarsal head resection is still used to resolve non-healing plantar forefoot ulcers in diabetic patients.49 Overall, the published experience with metatarsal head resection deals with diabetic and rheumatoid patients,24,43,564356 and the evidence is insufficient (Grade I recommendation) to support its use in any of these groups of patients. Flexor-to-Extensor transfer for the treatment of metatarsophalangeal joint instability of the second toe Originally described for the treatment of a flexible clawtoe deformity, transfer of the flexor digitorum longus tendon to the dorsum of proximal phalanx has become increasingly popular in order to treat painful instability of the second MTP joint.8,17,44 Results and complications Although several studies have confirmed the effectiveness of a flexor-to-extensor transfer, these investigations report variable levels of satisfaction, with results ranging from 51% to 89%. Also, incomplete correction after tendon transfer in patients with subluxated MTP joints has also been reported in the literature.5844 In a retrospective series reported by Myerson and coworkers (Level IV evidence), a total of 64 feet (59 patients) were evaluated after tendon transfer for painful instability of the second toe, with an average followup of 45 months. A cross-over toe was present in 87% of cases with a stage II deformity being the most common. Seven cases had vertical subluxation of the joint. In additional to a flexor-to-extensor tendon transfer, a second metatarsal Weil osteotomy was done in 29 feet, a proximal interphalangeal (PIP) joint resection arthroplasty in 22 feet, Foot & Ankle International/Vol. 29, No. 8/August 2008 and a PIP joint fusion in nine feet. At final followup 37% had residual second MTP dorsiflexion contracture while 16 feet had persistent medial deviation. The second toe was stable to stress manipulation in 46 feet. Complications arose in twenty cases. Twenty-five patients (29 feet) were very satisfied, 15 satisfied with minor reservations, six with major reservation, and 14 patients were unhappy with the outcome. The authors concluded that although the function of the second toe improved as a result of pain relief in most patients, a substantial number remained dissatisfied due to residual stiffness of the toe. They stated that the procedure must be used with a full understanding of potential complications and patient dissatisfaction Generally, complications experienced after this procedure are uncommon. However, swelling and stiffness of varying degrees, transient numbness of the involved toes; hyperextension of the DIP joint and recurrence of flexion at the PIP joint may occur and impair overall outcome. Based on the results from these Level III and Level IV studies, fair evidence (Grade B recommendation) exists to support the use of a flexor-to-extensor tendon transfer in paints with metatarsalgia due to painful instability of the lesser MTP joints. SUMMARY The optimal treatment of metatarsalgia remains controversial. Principles that underlie the diagnosis and management of metatarsalgia appear to include: 1. Concentrated repetitive loading over a prominent metatarsal head during the second and third-rocker stages of gait leads to chronic irritation to skin, softtissues, MTP synovium, and/or digital nerves producing localized forefoot pain characteristic of metatarsalgia. 2. Metatarsalgia can be considered primary or secondary. Primary metatarsalgia results from metatarsal head overload due to intrinsic causes such as a long metatarsal, a plantarflexed metatarsal, or a dorsiflexed first ray leading to second metatarsal overload. Secondary metatarsalgia results from extrinsic causes such as a metatarsal fracture, malunion, Freiberg’s infraction, and the sequelae of metabolic diseases such as rheumatoid arthritis and gout. 3. Metatarsalgia is often associated with subluxed and dislocated lesser MTP joints. These deformities lead to distal migration of the plantar fat pad and predispose to increased loading over the prominent metatarsal head. 4. Many patients with metatarsalgia can be treated nonoperatively with good success. Non-operative treatment may include: comfortable shoes with a wide toe box, a comfortable insert with a metatarsal pad or bar to disperse the force more widely over the forefoot, corticosteroid injections, anti-inflammatory and/or regular shaving of a prominent callus. METATARSALGIA 877 5. Metatarsalgia secondary to overload of one or more metatarsal heads can often be treated effectively with surgery if non-operative management is unsuccessful. Surgery is designed to relieve localized forefoot force concentrations often by repositioning the metatarsal head via a metatarsal osteotomy and/or by correcting subluxation of an MTP joint. REFERENCES 1. Barouk, LS: [Weil’s metatarsal osteotomy in the treatment of metatarsalgia]. 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