You are in: eMedicine Specialties > Orthopedic Surgery > FOOT AND ANKLE Claw ToeArticle Last Updated: Feb 28, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: James K DeOrio, MD, Director of Foot and Ankle Fellowship Program, Assistant Professor of Orthopedic Surgery, Orthopedic Surgery, St. Luke's Hospital, Jacksonville, Florida James K DeOrio is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Orthopaedic Foot and Ankle Society, Florida Medical Association, and German Society of Neurology Editors: John S Early, MD, Foot/Ankle Specialist, Texas Orthopaedic Associates, LLP; Co-Director, North Texas Foot and Ankle Fellowship Baylor University Medical Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Shepard R Hurwitz, MD, Executive Director Designate, American Board of Orthopaedic Surgery; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Jason H Calhoun, MD, FAAOS, Chairman, J Vernon Luck Distinguished Professor, Department of Orthopedic Surgery, University of Missouri Author and Editor Disclosure Synonyms and related keywords: lesser toe deformity, hammertoe, hammer toe, curly toe, mallet toe, toe deformity, toe disorders, foot disorders, metatarsalgia, metatarsophalangeal joint flexibility, MTP joint flexibility, proximal interphalangeal joint flexibility, PIP joint flexibility, distal interphalangeal joint flexibility, DIP joint flexibility, PIP flexibility, DIP flexibility, MTP flexibility, toe calluses, toe erythema INTRODUCTIONSection 2 of 12
  History of the ProcedureThe term claw toe is most likely derived from the affected toe's similarity in appearance to the claw of an animal or talon of a bird. The talon typically curves upward before it makes a descending C-shaped curve (see Image 1). ProblemA claw toe is a lesser toe with dorsiflexion of the proximal phalanx on the lesser metatarsophalangeal (MTP) joint and concurrent flexion of the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints (see Images 2-3). Claw toe is differentiated from hammer toe by the combined dorsiflexion of the MTP joint and plantar flexion of the DIP joint in claw toe. In contrast, a hammer toe may have some hyperextension at the MTP joint or some flexion at the DIP joint, but not both concurrently. Typically, the DIP joint is extended in a hammer toe (see Images 5-6). Hammer toe is differentiated from curly toe, which has combined plantar flexion of all 3 joints (see Image 6), and from a mallet toe, which has a neutral position of the MTP and PIP joints and flexion at the DIP joint (see Images 7-8). The Table contains descriptions of lesser toe deformities. Clawing often affects multiple toes (see Image 9).1, 2, 3, 4 Table. Lesser Toe Deformities
*Cannot coexist FrequencyThe prevalence of claw and hammer toe deformities ranges from 2-20%, with gradually increasing frequency as people age. Therefore, claw toe is most often seen in patients in the seventh and eighth decades of life. Women are affected 4-5 times more than men. Little is mentioned in the literature regarding these deformities in non-shoe-wearing populations.5, 6, 7, 8 Most people have no underlying disease responsible for the claw toe deformity, but it can occur in association with neuromuscular diseases, such as multiple sclerosis, Friedreich ataxia, Charcot-Marie-Tooth disease, cerebral palsy, mild dysplasia, stroke, and lumbar nerve root impingement. Metabolic diseases, such as diabetes and inflammatory arthropathies (eg, rheumatoid arthritis, psoriasis), can also be accompanied by claw toe deformity. EtiologyClaw toe deformity results from altered anatomy and/or neurologic deficit, resulting in an imbalance between the intrinsic and extrinsic musculature to the toes.9, 10 PathophysiologyThe extensor tendon crosses and is held over the MTP joint by an aponeurotic band of fibrous tissue. Although it does not insert into the proximal phalanx, it is able to dorsiflex the proximal phalanx of the MTP joint through this aponeurotic band, which goes around the MTP joint and is inserted onto the plantar plate (see Image 10). The extensor tendon splits into 3 parts over the proximal phalanx. The central slip attaches itself to the dorsal aspect of the base of the middle phalanx. The medial and lateral slips rejoin distally to insert on the dorsal aspect of the base of the distal phalanx (see Image 11). The extensor tendon is only capable of extending the PIP and DIP joints when the MTP joint is in neutral flexion. Otherwise, this is accomplished by the intrinsic musculature. 11, 12, 13 14 The intrinsics are made of the lumbricals, which are strong extenders of the PIP and DIP joints by virtue of their attachment onto the extensor sling and the interossei. Interossei are weak extensors of the interphalangeal joints because so few fibers reach the extensor sling. Furthermore, when the MTP joint is hyperextended, the lumbrical power in extending the PIP and DIP joints is reduced because of a mechanical disadvantage. The flexor digitorum longus (FDL) tendon inserts into the plantar aspect of the distal phalanx, and the flexor digitorum brevis inserts onto the middle phalanx. Thus, no major antagonist to dorsiflexion of the proximal phalanx is present. Hence, when the proximal phalanx dorsiflexes, static tightening of the flexors occurs, which subsequently flexes the PIP and DIP joints. Stabilization of the lesser MTP joint comes from the static restraint of the plantar plate and the collateral ligaments. The collateral ligaments have been reported as the primary stabilizers of the lesser MTP joint. The 2 sets of collateral ligaments both emanate from the lateral metatarsal head. The phalangeal collateral ligament inserts into the proximal phalanx, and the accessory collateral ligament inserts onto the plantar plate. The plantar plate is attached from the base of the proximal phalanx to an origin on the metatarsal head, just proximal to the plantar articular cartilage. When the collateral ligaments and plantar plate lose resiliency or are stretched through repetitive dorsal directing forces on the proximal phalanx from ground reactive forces, the proximal phalanx dorsiflexes. Without a strong plantar flexor attached to the proximal phalanx, the proximal phalanx remains in dorsiflexion, and the PIP and DIP joints subsequently flex (see Image 12). When the flexed position of the PIP and DIP joints remains constant, the collateral ligaments fibrose along the sides of the PIP and DIP joints, and the position of their joints becomes fixed. When this occurs, the claw toe deformity becomes rigid, whereas previously it was considered flexible. This separation of flexible and rigid most often occurs at the PIP joint. ClinicalPresentation Patients with claw toe deformities can present with a variety of symptoms related to the position of the toe. Patients most often report pain at the dorsal PIP joint from an impingement of the toe on the shoe. A callus or erythema is present over the dorsal PIP joint where it abuts the shoe. Patients also may report pain at the tip of the toe from pressure against the point of the distal phalanx.15 Patients can have a callus at the tip of the toe and a malformed nail, especially patients with diabetes and neuropathies (see Image 13). When pain beneath the callus exceeds the neuropathic threshold in a patient with diabetes, an abscess may be present beneath the callus, which is discovered only when the callus is debrided. The other source of pain is the MTP joint, which develops synovitis because of irritation from its extended position and instability. Another less often seen presentation is impingement of the lateral claw toe on the adjacent toe, causing a callus or soft corn on the medial border of the claw toe. This is usually secondary to clawing of the fourth or fifth toe. Finally, the relative increased pressure beneath the metatarsal head from the inability of the toe to share in weightbearing can result in metatarsalgia. This occurs secondary to distal migration of the plantar fat pad with hyperextension of the MTP joint. Physical examination Assessing claw toe primarily consists of a physical examination, with additional tests as required. With the patient sitting, each of the 3 joints (ie, MTP, PIP, DIP) is tested for flexibility in the sagittal plane and stability in the frontal and sagittal planes. Vascularity of the toe is assessed clinically, and the presence of calluses or erythema is duly noted. Normal sensation can be determined by the patient's ability to feel a 0.5-g force with a monofilament pressure device. If the patient cannot detect a 10-g force applied with a monofilament pressure device, this indicates loss of protective sensation. INDICATIONSSection 3 of 12
Indications for treatment are the presentations described in Clinical that produce pain. RELEVANT ANATOMYSection 4 of 12
See Pathophysiology. CONTRAINDICATIONSSection 5 of 12
Contraindications to operative treatment include poor vascularity to the toe (including vascular problems that could lead to ischemia and possible need for amputation following surgery, eg, diabetes, atherosclerosis) and poor skin quality. Of course, an open infected wound, for instance on the PIP joint from shoe pressure, should also be resolved prior to surgery. WORKUPSection 6 of 12
Lab Studies
Imaging Studies
Other Tests
TREATMENTSection 7 of 12
Medical therapyMedical treatment for claw toes depends on the underlying cause. Therefore, anti-inflammatory drugs, glucose-lowering agents, and antibiotics all may be appropriate. However, these treatments are not believed to reverse the claw toe position. Conservative treatment After medical treatment is initiated, consider conservative therapy, including avoidance of wearing high-heeled, narrow-toed shoes, which increase dorsal ground reactive forces on the toe and crowd the toes against each other, producing impingement. Shoes with a wide toe box, soft upper shoe, and stiff sole to absorb dorsally directed forces against the plantar plate are appropriate. Some high-quality athletic shoes fulfill these criteria. A metatarsal bar can be added to the shoe to avoid metatarsal pressure, but patients more easily accept metatarsal pads. Cushioning sleeves or stocking caps with silicon linings can relieve pressure points at the PIP joint and tip of the toe (see Image 14). A longitudinal pad beneath the toes can prevent point pressure at the tip of the toes (see Image 15).16, 17 Surgical therapyBecause the MTP joint is always dorsiflexed by definition, some correction of its position is necessary to restore a more neutral angle at the MTP joint. This consists of Z lengthening of the extensor tendon, dorsal MTP capsulotomy, and collateral ligament release (see Images 16-20). If deviation is present in the frontal or coronal plane in addition to claw toe, the loose collateral ligament side can be imbricated instead of released. 10, 18, 19 20, 21 At the PIP joint (if it is completely flexible), an FDL transfer to extensor tendon can bring the toe into alignment. This is accomplished by making a longitudinal cut across the plantar MTP proximal skin crease, retracting the skin with 1 or 2 small Meyerding retractors if necessary, splitting the tendon sheath, isolating the FDL tendon between the FDL brevis tendons, passing a small curved hemostat beneath the long flexor to establish tension in the tendon, and then cutting the tendon distally through a small stab incision in the skin just proximal to its attachment. The 2 distal raphes are held with 2 hemostats, and blunt separation is accomplished by cutting the distal connecting raphe of the FDL tendon into 2 parts with tenotomy scissors. Through the dorsal incision used to address the Z tendon lengthening, curved hemostats are directed circumferentially around the proximal phalanx. The tip of the FDL tendon raphe is grasped on the medial side and brought from the plantar wound dorsally. A similar technique is used to grab the lateral raphe and bring it dorsally. The tendons are attached to themselves and to the repaired extensor Z-lengthened tendon with 2-0 absorbable suture (see Images 21-32). Absorbable suture prevents the formation of a permanent knot bump on the dorsal aspect of the toe. Image 52 is a 4-minute movie showing the tendon transfer. If the PIP is fixed in flexion or cannot be brought back easily to a neutral position, remove the distal portion of the proximal phalanx along with the articular cartilage of the middle phalanx. If only a PIP resection is required (an FDL transfer is not needed), a shorter longitudinal incision can be made dorsally over the MTP joint and proximal phalanx for the Z lengthening, dorsal capsulotomy, and collateral ligament release surgery. A transverse incision can then be made at the PIP joint for correction of the fixed deformity (see Images 33-40). If an FDL transfer is necessary along with a PIP resection, this may be accomplished with extension of the dorsal longitudinal MTP incision over the PIP joint. Once through the skin, a continuation of the Z lengthening of the tendon may be accomplished across the PIP joint. The distal portion of the proximal phalanx is isolated by cutting the collateral ligaments and exposing the bone. The distal portion of the proximal phalanx is cut with a small, sharp, bone-cutting device (eg, saw), just proximal to the flare of the condyles. The articular cartilage is then removed from the proximal portion of the middle phalanx. A 0.54-mm doubly pointed Kirschner wire (K-wire) is driven into the distal-cut bony surface of the middle phalanx, taking care to keep the guidewire in the center of the bone to avoid eccentric positioning. The K-wire is brought out of the tip of the toe while the DIP joint is held in neutral position. The K-wire is then grasped distally and drilled back through the proximal phalanx across the metatarsal head, holding the interphalangeal joints in neutral position with slight flexion at the MTP joints (see Images 21-50).22 The resected PIP joint is now inspected to avoid eccentricity and bone prominence. If this is found, the prominence is resected or the guidewire is replaced. This guidewire (being somewhat larger than the previously recommended 0.54-mm K-wires) is less likely to break, does not become unstable (which would cause infection), and can be left in place for 4 weeks to increase the chance of fusion and/or fibrosis of the PIP joint. If the PIP joint is not resected, stabilization of soft tissue at the MTP joint is important to promote ultimate healing in the corrected position. Therefore, a K-wire can be driven from the articular cartilage of the proximal phalanx out of the tip of the toe and back antegrade through the metatarsal head. This can also be attempted retrograde from the tip of the toe, with the toe in a slightly plantar-flexed position at the MTP joint and neutral at the PIP and DIP joints. This is more difficult. However, even if the pin only engages the capsular tissue of the MTP joint, this is often enough to keep the joint relatively stable. The pin is removed after 2 weeks, because the goal is joint stability, not arthrodesis. The joint may be taped for an additional 4 weeks if further immobilization is necessary. Almost always, the DIP joint is flexible in a claw toe and is relieved with a flexor-to-extensor transfer. However, should a fixed DIP joint be found, especially if it is part of the problem (ie, pressure on the nail or the tip of the toe), resection of the distal portion of the proximal phalanx and articular portion of the distal phalanx can be performed in a similar fashion to that used on the PIP joint. A pinning technique similar to that described above also may be used. Sometimes, such chronic dorsal dislocation of the proximal phalanx is present on the metatarsal head that reduction of the proximal phalanx is not possible or, if attempted, leaves an extreme tightness across the MTP joint, resulting in vascular compromise. In this instance, an osteotomy, from the proximal dorsal articular surface of the metatarsal head in a direction plantar proximal along a plane parallel to the sole of the foot, allows metatarsal head retraction and reduction of the tension in the neurovascular bundle. The dorsal lip of the metatarsal shaft can be removed, and the head is fixed to the remaining shaft with a screw or continuation of the lesser toe pin into the dorsal metatarsal head and then into the center portion of the shaft. This technique is preferable to metatarsal head resection, which can result in a transfer lesion to another metatarsal head. Forefoot surgery is typically performed in an outpatient setting. A fresh dressing is applied the next day, and stitches are removed after 2 weeks. Arthrodesis pins are removed after 4 weeks, and the other types of pins are removed after 2 weeks. Patients may shower with pins protruding from the toes. Follow-upImage 51 is an algorithm to help determine the appropriate surgical procedure and postoperative treatment. COMPLICATIONSSection 8 of 12
The most common complication is pain from recurrent deformity in the sagittal or frontal plane due to inadequate correction of the deformity, failure to obtain an arthrodesis or stable fibrosis, or premature or patient-prompted pin removal. Other complications include pain from failure of the wound to heal, infection, numbness, dysesthesias, vascular compromise with blistering or eschar formation, and loss of the toe. If pallor of the toe is still present 30 minutes following surgery, the toe is manipulated into a more dorsiflexed position with the pin in place. If the toe does not become pink within 15 minutes, the pin is removed. OUTCOME AND PROGNOSISSection 9 of 12
The experiences of other authors indicate that complete correction of the toe is necessary to achieve the best result. Of course, this presumes careful attention to detail and a toe with normal vascularity. Taylor18, 19 and Pyper,23 via transfer of both the long and short flexor to the extensor hood without bony resection, achieved only 72% and 51% good results, respectively. Pyper also noted that with soft-tissue procedures alone, the deformity recurred and results were somewhat unpredictable. Therefore, Frank and Johnson24 and McCluskey et al25 recommend PIP resection along with soft tissue procedures to realign the toe. Barbari and Brevig26 reviewed 31 patients who had surgery on multiple toes. These authors concluded that the best cosmetic results were achieved in younger patients, and they noted that active or passive motion in the interphalangeal joints was present in 60% of these cases. Of course, restriction in range of motion is an intended outcome of the procedure. Patients must be aware that in most instances, they will sacrifice prehensile action of the toe for less pain, will have better shoe-wearing capabilities, and, ideally, will have an improved cosmetic result. Specific disease entities seem to fare similarly; Cyphers and Feiwell27 reported 60% good results in patients with myelomeningocele. FUTURE AND CONTROVERSIESSection 10 of 12
A future prospective study that separates claw toes from hammer toes, fixed from flexible, severe from mild, and bony correction (ie, PIP and metatarsal neck osteotomies) from soft-tissue procedures alone is necessary. The addition of an extensor tendon transfer beneath the intermetatarsal ligament with reattachment to the proximal phalanx may help improve continued deformity at the time of surgery or recurrent postoperative dorsiflexion deformity. When to perform each of the procedures on a claw toe and the extent of the surgical procedure on a single toe remain controversial. Other controversies are a bolster suture above the PIP joint in lieu of a pin, the size of the toe fixation pin, the duration it needs to remain in place, and whether or not it needs to cross the MTP joint. MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
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