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Hammertoes represent one of the most common forefoot deformities and arise from an imbalance between intrinsic and extrinsic musculature acting on the lesser digits. This course reviews this condition, characterized by flexion at the interphalangeal joints, and its various manifestations, including classic hammertoe, mallet toe, and claw toe deformities. Hammertoes disrupt normal pressure distribution and balance during gait, often leading to pain, callus formation, skin breakdown, cosmetic concerns, and progressive functional impairment. This activity provides clinicians with a comprehensive review of the pathophysiology, biomechanics, and clinical evaluation of hammertoe. The evaluation, which requires careful assessment of biomechanics, joint flexibility, and metatarsophalangeal joint stability using weight-bearing examination and appropriate imaging, and the management, involving conservative strategies or surgical correction tailored to the involved joints and underlying pathology, are also discussed. Participants will also gain an understanding of the distinguishing features between flexible and rigid deformities, associated metatarsophalangeal joint instability, appropriate conservative therapies, and indications, techniques, and potential complications of surgical intervention. This activity for healthcare professionals is designed to enhance the learner's competence in identifying hammertoes, performing the recommended evaluation, and implementing an appropriate interprofessional approach when managing this condition  to optimize patient outcomes and quality of life. Objectives: Identify key etiologic factors contributing to hammertoe deformities. Interpret diagnostic findings relevant to the evaluation of hammertoe. Select appropriate management techniques based on the characteristics of the hammertoe deformity. Collaborate with interprofessional team members to improve care coordination and outcomes in patients with hammertoe deformity. Access free multiple choice questions on this topic.

Hammertoes rank among the most common deformities of the forefoot.[1] The condition develops from an imbalance between weak intrinsic muscles and stronger extrinsic muscles acting across the metatarsophalangeal joints (MTPJ) of the lesser digits. Hammertoe deformity features flexion at the interphalangeal joints (IPJs) and falls into 3 categories: classic hammertoe, mallet toe, and claw toe. Because the lesser digits play a critical role in balance and pressure distribution during gait, deformity often leads to compensatory gait alterations, cosmetic changes, callus formation, and pain. Multiple treatment options exist and require careful consideration. Initial management emphasizes conservative measures, including footwear with a wider toe box, toe pads, and appropriate orthotic support. Persistent pain with progressive deformity despite conservative care may warrant surgical intervention. Variability in deformity characteristics, particularly rigidity, influences surgical planning, underscoring the importance of a thorough clinical evaluation for durable correction. Anatomical Structures Deformities of the lesser digits arise from disproportionate forces between intrinsic and extrinsic musculature. Dominance of extrinsic muscles promotes extension of the proximal phalanx with potential metatarsophalangeal joint hyperextension, combined with flexion at the proximal and or distal interphalangeal joints (PIPJ or DIPJ) due to an unopposed long flexor.[2] The extensor digitorum longus functions primarily during the swing phase of gait to dorsiflex the foot. Its tendon divides into 4 slips across the ankle, each supplying a lesser digit, and further separates over the proximal phalanx into 3 slips. The central slip inserts into the base of the middle phalanx, while the 2 lateral slips unite to form a terminal tendon inserting into the base of the distal phalanx.

The extensor digitorum longus functions primarily during the swing phase of gait to dorsiflex the foot. Its tendon divides into 4 slips across the ankle, each supplying a lesser digit, and further separates over the proximal phalanx into 3 slips. The central slip inserts into the base of the middle phalanx, while the 2 lateral slips unite to form a terminal tendon inserting into the base of the distal phalanx. The extensor digitorum brevis contains 3 slips that insert into the fibrous expansion of the extensor digitorum longus at the metatarsophalangeal joints of digits 2, 3, and 4, forming the extensor hood apparatus. This anatomic arrangement produces strong dorsiflexion at the metatarsophalangeal joint with limited dorsiflexion at the interphalangeal joints. The flexor digitorum longus divides into 4 slips, inserting into the distal phalanges, generating flexion at the DIPJs, while the flexor digitorum brevis inserts into the middle phalanx to flex the PIPJs. Absence of a flexor insertion on the proximal phalanx opposing MTPJ extension results in progressive flexion at the PIPJs and DIPJs. MTPJ instability frequently accompanies digital deformities. Stability depends on the plantar plate and the accessory and proper collateral ligaments on the medial and lateral aspects of the joint. Attenuation or rupture of these structures produces joint instability. Plantar plate rupture may lead to subluxation, while collateral ligament injury can cause medial or lateral drift with valgus or varus rotation of the affected digit, resulting in a "cross-over deformity".[3]

Hammertoe deformities arise from multiple congenital and acquired factors, with biomechanical dysfunction representing the most widely accepted underlying contributor. Disruption of normal force balance across the lesser digits alters joint alignment and muscle function, leading to progressive deformity. The etiology of lesser digit deformities encompasses a broad range of contributing conditions and influences, including: Neuromuscular conditions Diabetes Inflammatory arthropathies Ill-fitting shoes and high heels Intrinsic muscle imbalance Hallux valgus Long metatarsals Pes planus [4][5]

Deformities of the lesser digits are among the most common problems affecting the foot and ankle, accounting for up to 20% of reported cases. Lesser toe problems increase with advancing age, occur more frequently in women, and have high heritability.[6] The condition also shows a strong correlation with the presence of a hallux abductovalgus deformity, increased length of the involved toe, and pes planus foot posture.[7][8]

Digital deformities present with varied characteristics and may appear as static or dynamic conditions, flexible or rigid in nature, and in association with additional pathologies, eg, Charcot-Marie-Tooth disease, cavus and planus foot deformities, and rheumatoid arthritis. Rheumatoid arthritis produces hammertoe deformity through progressive destruction of the MTPJ, leading to subluxation and eventual dislocation. Neuropathic lesser toe deformities commonly demonstrate rigid involvement of the PIPJs and DIPJs, accompanied by MTPJ deformities of varying severity.[9] Neuromuscular disorders, anatomic variations (eg, a second ray longer than the first), and improperly fitted footwear disrupt the balance of intrinsic and extrinsic forces acting on the digit, resulting in deformity.[2] Three primary biomechanical categories explain the development of hammertoe deformity and the loss of muscular balance at the MTPJ: flexor stabilization, extensor substitution, and flexor substitution. The following mechanism produces deformity at distinct levels of the lesser digits and influences clinical presentation and management strategies: Flexor stabilization: This mechanism is the most common cause of digital deformities and occurs with excessive pronation. With the pronation of the subtalar joint, flexor stabilization unlocks the midtarsal joint, as well as causing hypermobility of the forefoot. In an attempt to stabilize the forefoot, the flexors now fire earlier, longer, and more forcefully, overpowering the interosseous muscles. Flexor stabilization is easily recognizable by adductovarus rotation of the fifth digit, as well as hammering or clawing of the lesser digits in stance position. Flexor substitution: This occurs when the triceps surae is weak, and the deep and lateral leg muscles try to compensate for inadequate plantarflexion, resulting in the flexors gaining a mechanical advantage over the interossei. Extensor substitution:  Extensor substitution is clinically recognizable by bowstringing of the extensor tendons. In this mechanism, the extensors gain a mechanical advantage over the lumbricals, leading to contractions at the MTPJ.

Clinical History Hammertoe commonly presents as a chronic, progressive deformity characterized by flexion at the PIPJ of the affected digit. The involved toe often becomes erythematous and painful. Patients frequently report chronic pain that worsens with ambulation and shoewear, with symptom severity increasing as the deformity advances. Skin inspection may reveal blisters, callosities, ulcerations, or irritation located dorsally over the PIPJ, plantarly beneath the metatarsal head, or at the distal tip of the toe due to increased localized pressure. Some patients report pain on the plantar aspect of the metatarsal head, a finding commonly associated with hyperextension, subluxation, or dislocation of the MTPJ.[10] Physical Examination A comprehensive physical examination requires assessment of foot biomechanics to identify contributing factors to hammertoe deformity and associated conditions, eg, hallux valgus. Evaluation in both standing and seated positions allows accurate recognition of deformities that may not appear during nonweight-bearing assessment alone. Clinical assessment typically includes both weight-bearing and nonweight-bearing examinations. MTPJ stability should be assessed with the Lachman test, and the flexibility of all deformities should be documented. Neurovascular status requires evaluation, including palpation of peripheral pulses. Flexible hammertoes usually appear during weight-bearing and correct with passive placement of the ankle into a neutral position, whereas rigid deformities remain fixed. Passive correction at the PIPJ assists in guiding treatment decisions. Assessment of MTPJ range of motion and joint quality further informs management. Increased tenderness or instability over the articular surface of the metatarsal head suggests pathology requiring treatment beyond isolated hammertoe correction.[11]

Accurate evaluation of hammertoes benefits from the use of diagnostic imaging to define deformity characteristics, associated pathology, and surgical planning. Radiographic Studies Weight-bearing anterior-posterior, oblique, and lateral radiographs play a central role in assessing hammertoe deformities. Radiographs allow evaluation of joint contractures and visualization of the medullary canal of the proximal phalanx, a finding often associated with hammertoe deformities and referred to as the "gun barrel" sign (see Images. Radiographic Studies and Hammertoe X-Ray). Imaging also facilitates measurement of relative metatarsal lengths, identification of hallux valgus, and detection of metatarsus adductus through assessment of overall forefoot alignment, making it particularly valuable in preoperative planning. Preoperative determination of hammertoe length can be performed by drawing a transverse line connecting the distal phalanges of adjacent digits; any overlap by the affected toe indicates elongation.[8] Magnetic Resonance Imaging Magnetic resonance imaging (MRI) is indicated when plantar plate rupture is suspected or when additional soft tissue or osseous pathology requires evaluation. MRI provides detailed visualization of avascular necrosis of the metatarsal head—most commonly affecting the second metatarsal—as well as cartilage defects and surrounding soft tissue structures. Patients with comorbidities, eg, diabetes, distal peripheral neuropathy, or peripheral vascular disease, may also benefit from noninvasive arterial studies to assess vascular status and healing.

Hammertoe deformities can be extremely painful and significantly impact a person’s quality of life. Therefore, surgical correction of hammertoe deformities is among the most commonly performed surgical procedures on the forefoot.[8] Nonsurgical Treatment Before the surgical route is considered, conservative treatments are usually attempted and should be tried before surgery. Conservative therapies aim to improve the quality of the patient's life and to relieve pain, with the overall goal of avoiding or at least delaying a potential surgery.[12] These treatments focus on reducing pressure dorsally over the involved PIPJ, plantarly to its metatarsal head, and at the tip of the involved toe. For lesser digit deformities, having the patient begin using insoles or orthotics, and shoes with a wide toe box to accommodate the deformities and alleviate the pain that may result from impingement of the digits, is recommended.[4] High-heeled shoes are not recommended due to the continued increase in the transfer of pressure to the forefoot. Padding or periodic shaving of the painful calluses may alleviate some of the patient’s discomfort, and strapping or taping the flexible deformities may improve some alignment. These modifications can be beneficial for managing forefoot disorders; however, these techniques are not a permanent solution for the deformity.[5] Surgical Treatment Once flexion contractures form and become persistent, along with pain, surgical intervention may be indicated. Historically, this has been based on balancing the extensor and flexor forces by altering the relative lengths of the toe, including its osseous structures and tendons. The distinction between flexible and rigid hammertoes, as well as the absence or presence of associated MTPJ deformity, will help to guide you to conservative care or to the best surgical intervention. Recent findings have shown that lesser toe surgery accounts for 48% of forefoot surgeries, with hammertoe surgery being the most common procedure.[1][2]

Once flexion contractures form and become persistent, along with pain, surgical intervention may be indicated. Historically, this has been based on balancing the extensor and flexor forces by altering the relative lengths of the toe, including its osseous structures and tendons. The distinction between flexible and rigid hammertoes, as well as the absence or presence of associated MTPJ deformity, will help to guide you to conservative care or to the best surgical intervention. Recent findings have shown that lesser toe surgery accounts for 48% of forefoot surgeries, with hammertoe surgery being the most common procedure.[1][2] Treatments must address and evaluate the deformity at all joints of the affected digit, including DIPJ, PIPJ, and MTPJ. The most common surgical techniques employed to address rigid, or so-called fixed, hammertoe deformities are PIPJ resection arthroplasty or PIPJ arthrodesis. For the correction of flexible hammertoes, soft-tissue release is often used to maintain the toe's structural stability. Two approaches for correcting lesser toe deformities are open surgery or minimally invasive surgery. Both approaches showed good results with no statistically significant differences in fusion success or complications.[13][14] If digital surgery is warranted and instability is noted at the MTPJ, this should be addressed as a concomitant procedure, eg, an osteotomy to address the affected metatarsal and plantar plate repair. Plantar plate rupture may be diagnosed on physical examination with the Lachman test, which is considered the most accurate clinical test for diagnosing MTPJ pathology. During the test, the metatarsal head should be stabilized while the proximal phalanx is displaced dorsally. If the displacement exceeds 2 mm or 50% of the MTPJ, the test is positive, indicating a plantar plate rupture or insufficiency. A dorsal medial deviation of the digit, often affecting the second toe, is commonly seen as an objective finding of MTPJ instability along with exquisite point tenderness just distal to MTPJ at the insertion of the plantar plate apparatus into the base of the proximal phalanx. PIPJ resection arthroplasty

If digital surgery is warranted and instability is noted at the MTPJ, this should be addressed as a concomitant procedure, eg, an osteotomy to address the affected metatarsal and plantar plate repair. Plantar plate rupture may be diagnosed on physical examination with the Lachman test, which is considered the most accurate clinical test for diagnosing MTPJ pathology. During the test, the metatarsal head should be stabilized while the proximal phalanx is displaced dorsally. If the displacement exceeds 2 mm or 50% of the MTPJ, the test is positive, indicating a plantar plate rupture or insufficiency. A dorsal medial deviation of the digit, often affecting the second toe, is commonly seen as an objective finding of MTPJ instability along with exquisite point tenderness just distal to MTPJ at the insertion of the plantar plate apparatus into the base of the proximal phalanx. PIPJ resection arthroplasty Resection of the head of the proximal phalanx will shorten the distance from the origin to the insertion of the flexor digitorum longus and flexor digitorum brevis, causing weakness. However, the extensors will not be weakened since their insertions are into the MTPJ via the extensor hood apparatus. This procedure is therefore most effective in treating flexor-induced hammertoe deformities that are semirigid or rigid, as well as for elongated digits. Due to the loss of structural integrity, multiple arthroplasties should be avoided. PIPJ arthrodesis The fusion of the PIPJ is an effective procedure for most deformities related to the digits. PIPJ arthrodesis is particularly useful and preferred when significant deforming forces are present. This surgical technique is also preferred when all or multiple digits are involved, since PIPJ arthrodesis maintains the structural stability of the toes. The fusion converts the toe to a rigid lever arm, leading to flexor digitorum longus and flexor digitorum brevis tendons now augmenting the intrinsic muscles, providing plantarflexion stability at the MTPJ. Whether intramedullary implants or K-wire should be the standard of care for PIPJ arthrodesis has not yet been established.[15] Tendon transfers

The fusion of the PIPJ is an effective procedure for most deformities related to the digits. PIPJ arthrodesis is particularly useful and preferred when significant deforming forces are present. This surgical technique is also preferred when all or multiple digits are involved, since PIPJ arthrodesis maintains the structural stability of the toes. The fusion converts the toe to a rigid lever arm, leading to flexor digitorum longus and flexor digitorum brevis tendons now augmenting the intrinsic muscles, providing plantarflexion stability at the MTPJ. Whether intramedullary implants or K-wire should be the standard of care for PIPJ arthrodesis has not yet been established.[15] Tendon transfers Transferring the flexor digitorum longus and flexor digitorum brevis tendons to the dorsal aspect of the proximal phalanx converts these tendons to plantar flexors of the MTPJ during weight-bearing in the same fashion as PIPJ arthrodesis. This procedure is indicated for flexible deformities. For the extensor tendon transfer, the xtensor digitorum longus may be transferred to the metatarsal neck to eliminate the deforming force. Tenotomy Another procedure indicated for a flexible deformity is a flexor tenotomy at the PIPJ, which effectively releases both the flexor digitorum longus and the flexor digitorum brevis. For mild, flexible extensor hammertoes, the extensor tenotomy is indicated. The tenotomy must be performed proximal to the extensor hood apparatus to release the pull effectively. If the incision is made at the MTPJ, it requires a full capsulotomy. Weil osteotomy Weil osteotomy is a distal oblique osteotomy that shortens the metatarsal and is most commonly performed to address hammertoes or claw toes. This procedure is often used to correct dislocations of the digits and angular deformities. Plantar plate repair Plantar plate repair is a procedure commonly performed in conjunction with a Weil osteotomy. This technique is typically performed via a dorsal approach, in which the injured or ruptured plantar plate is repaired with a suture.

Claw Toe Confusion has persisted in the literature regarding the precise definitions of hammertoes and claw toes, partly because treatment strategies often overlap, reducing the clinical impact of strict terminology. Coughlin and Mann distinguished claw toe deformity based on the involvement of the MTPJ.[16] Most experts define claw toe as a primary flexion deformity of the PIPJ and DIPJ combined with simultaneous hyperextension of the MTPJ. In contrast, hammertoe is typically characterized by primary flexion at the PIPJ, with the DIPJ remaining neutral or slightly hyperextended, and with or without MTPJ hyperextension.[4] Claw toe deformities tend to be more severe, frequently affecting multiple toes on both feet, and are commonly associated with neuromuscular conditions. The cavus foot represents the most typical foot type seen in conjunction with claw toes. Hammertoes, by comparison, often occur in isolation and most commonly affect the second toe. Other Differential Diagnoses The following differential diagnoses should also be considered when evaluating hammertoe deformities: Mallet toe (isolated flexion deformity at the DIPJ) Turf toe Sesamoiditis Gout Osteochondrotic lesion of the first metatarsal head Osteochondritis dissecans Metatarsalgia Metatarsal stress fracture

Hammertoe deformity represents a chronic, progressive condition, yet overall prognosis remains favorable. Following a thorough evaluation, management should begin with conservative measures. When pain persists or functional limitations continue, surgical intervention becomes appropriate. Postoperative recovery varies according to the procedure type, surgical technique, and surgeon preference. Standard postoperative protocols generally include partial weight-bearing with heel contact while using a specialized postoperative shoe for 2 to 6 weeks, followed by a transition into a rigid athletic shoe. Healing may take longer in patients who smoke or have diabetes. Common postoperative complications depend on the surgical approach and may include infection, nonunion, hematoma, numbness, and recurrence of deformity.[17] Recurrence and revision rates following digital deformity correction remain relatively high, with reported rates up to 10%. The second toe has a higher likelihood of recurrence than the third and fourth toes. Preoperative transverse deformities are associated with greater failure rates than primarily sagittal deformities. Addressing a deviated first MTPJ concurrently with first-ray surgery has been shown to reduce hammertoe recurrence by nearly 50%.[18] Recurrence may result from a tight flexor tendon or insufficient bone resection, while excessive bone removal can produce a flail toe, requiring careful intraoperative judgment.

Hammertoes usually start as mild deformities that progressively worsen over time, which can result in complications, eg, pain, gait imbalance, decreased quality of life, and skin changes, including callouses, corns, and blisters. Surgical correction of the hammertoe deformity may lead to complications, including: Nonunion Malunion Avascular necrosis Metatarsalgia Malalignment Infection Numbness PIP joint instability (flail toe) Pain Recurrent deformity Stiffness Vascular impairment Chronic edema Mallet toe [5][8]

Preventing the progression of hammertoe deformities relies on early recognition and modification of contributing factors. Patients should be educated on the importance of proper footwear, including shoes with a wide toe box to reduce pressure on the lesser digits, and the use of toe pads or orthotics to redistribute forces and alleviate discomfort. Taping or strapping flexible deformities can help maintain alignment and reduce abnormal stress during ambulation. Addressing biomechanical imbalances, eg, hallux valgus or altered gait patterns, may further limit deformity progression and reduce compensatory changes that can lead to callus formation or pain. Patient education should also include guidance on recognizing early warning signs, eg, redness, blisters, or localized tenderness, and the importance of seeking timely evaluation. When conservative measures fail, or the deformity becomes rigid or associated with MTPJ instability, surgical intervention may be indicated. Most patients can safely return to normal activities once cleared by their physician, underscoring the importance of adhering to postoperative instructions and follow-up care to achieve optimal functional outcomes.

Hammertoe deformities represent a common forefoot condition characterized by flexion of the IPJs, often resulting in pain, callus formation, and compensatory gait changes. Diagnosis relies on clinical evaluation, supported by weight-bearing radiographs to assess joint alignment, deformity severity, and underlying structural pathology. Initial management emphasizes conservative measures, including shoes with a wide toe box, orthotics, toe pads, and taping, with surgical intervention reserved for persistent pain, rigid deformities, or MTPJ instability. Surgical approaches vary based on deformity type, joint involvement, and patient-specific factors, with postoperative rehabilitation and long-term follow-up essential for restoring function and preventing recurrence. Effective management requires interprofessional collaboration among primary care physicians, podiatric surgeons, nurses, physical therapists, and other healthcare professionals. Physicians and advanced practitioners provide initial evaluation, conservative management, and surgical referral when indicated. Nurses support perioperative care, wound monitoring, and patient education, while physical therapists facilitate rehabilitation and gait retraining. Pharmacists contribute to safe pain management, including strategies to minimize opioid use. Coordinated communication across the care team ensures patient-centered care, enhances safety, improves functional outcomes, and supports adherence to long-term recovery and follow-up milestones.