You are in: eMedicine Specialties > Orthopedic Surgery > FOOT AND ANKLE Fifth-Toe DeformitiesArticle Last Updated: Jan 30, 2005AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: Stephen M Schroeder, DPM, Chairman of Podiatric Foot and Ankle Surgery, Medical Staff, Department of Surgery, The Vancouver Clinic Coauthor(s): Raymond O'Hara, DPM, Chief Resident, Department of Orthopedic Surgery, Yale-New Haven Hospital; Peter Blume, DPM, Director of Diabetic Foot Surgery, Department of Orthopedics, Yale New Haven Hospital; Clinical Assistant Professor, Department of Podiatric Surgery, Yale University School of Medicine; Enzo Sella, MD, Chief, Orthopedic Foot and Ankle Surgery, Yale-New Haven Hospital; Associate Clinical Professor, Department of Orthopedics and Rehabilitation, Yale University School of Medicine 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: toe deformities, hard corns, heloma durum, helomata durum, soft corns, heloma molles, helomata molle, ainhum, hammertoes, hammer toes, claw toes, overlapping toes, underlapping toes, curly toes, congenital varus toes, cock-up toes, little toe, small toes, kissing corns, epidermal hyperkeratosis, Ruiz-Mora procedure, syndactylization, arthroplasty, Z-plasty, flail toe, dorsiflexion contracture, plantarflexion contracture, capsulotomy, DuVries procedure, skin plasty, pinky toe pain, pinky toe deformity, toe pain INTRODUCTIONSection 2 of 10
  Since the advent of shoes, the fifth toe has been a source of discomfort for many people. Complaints typically involve poorly fitting shoes that create friction, irritation, and pain with each step. The problem can typically be solved conservatively with shoe modifications or proper foot maintenance; however, structural deformities of the toe often require surgical correction. History of the ProcedureFifth-toe deformities have been present since the evolution of bipedal ambulation. However, correction of these deformities did not become prevalent until the early 20th century, when many authors began describing different aspects of the problem, along with surgical procedures to help correct them. ProblemFifth-toe deformities comprise several congenital and developmental problems that affect the fifth digit. Most are associated with contractures at the metatarsophalangeal joint (MTPJ) and proximal interphalangeal joint (PIPJ), with or without varus rotation. ClinicalThe simplest lesions are hard corns (helomata durum) and soft corns (helomata molle). Both lesions are epidermal hyperkeratoses resulting from frictional or pressure irritation. They develop over bony prominences, such as enlarged phalangeal condyles or exostosis. Hard corns Hard corns result from intrinsic pressure from bony prominence combined with extrinsic pressure (typically in the form of footwear irritation) over the exposed fifth toe. The most common site is the dorsal lateral aspect of the PIPJ, but corns can also occur in the same location over the distal interphalangeal joint (DIPJ). The corn is typically associated with a hammertoe deformity (dorsiflexion contracture at the MTPJ and plantarflexion contracture at the PIPJ) that may have a slight varus rotational deformity. This makes the dorsal lateral aspect of the PIPJ more prominent and susceptible to footwear irritation. The corn that develops can be superficial or deep seeded; the latter is more painful. Additionally, a painful bursa may occur deep in the lesion in response to the constant pressure. In the neuropathic population, hard corns that go untreated can develop into ulcerations that lead to soft tissue and bone infection. Soft corns Soft corns develop between adjacent toes. Intrinsic pressure develops between adjacent condyles of the lateral fourth PIPJ abutting the medial fifth DIPJ, or the lateral fourth MTPJ abutting the medial fifth PIPJ. The lesions can develop on the skin over the lateral fourth PIPJ, medial fifth DIPJ, medial fifth PIPJ, or deep in the web space. Kissing corns Kissing corns result from 2 calluses rubbing against each other on adjacent toes. Kissing corns are usually painful when the toes are squeezed together. Maceration is often noted in the web space and may contribute to the development of kissing corns. When they occur, other common problems, such as fungal infections or verruca, need to be ruled out. If left untreated, these lesions may also develop into ulcerations in people with neuropathies. Hammertoe, claw-toe, and cock-up deformities are all variations of the same problem. The presence of a dorsiflexion contracture at the MTPJ and a plantarflexion contracture at the PIPJ is constant between the 3. The claw-toe deformity has the addition of a plantarflexion contracture at the DIPJ. The term cock-up deformity is typically used to describe a severe hammertoe, in which the proximal phalanx articulates at a nearly 90° angle to the fifth metatarsal and may be fixed in that position. A cock-up deformity can also be associated with plantar-plate ruptures or adhesions between the plantar MTPJ capsule and the metatarsal head. Contractures can develop for several reasons; however, they most frequently occur because of mechanical imbalances. The intrinsic foot musculature fails to stabilize the fifth toe at the MTPJ, PIPJ, and DIPJ, allowing the more powerful extrinsic flexors and extensors to act unchecked. This eventually leads to the deformities described above. Unlike the other conditions mentioned, overlapping and underlapping fifth toes are usually congenital deformities. The overlapping fifth toe is a common familial deformity with equal sex predilection and usually presents bilaterally. About half of patients become symptomatic because of pressure from footwear against the dorsal aspect of the toe and nail. The toe is dorsally hyperextended at the MTPJ with a varus rotation and medial deviation onto the top of the fourth digit. Contractures develop dorsomedially at the MTPJ and eventually form in the extensor digitorum longus (EDL) tendon and the dorsomedial skin overlying the MTPJ. The underlapping fifth toe is another common congenital deformity and is often referred to as a curly toe or congenital varus toe. This deformity may also occur bilaterally and has a high familial prevalence. The toe is plantarflexed at the MTPJ, rotated into a varus position, and positioned under the fourth digit. A contracture typically occurs at the plantar-medial MTPJ capsule and flexor digitorum longus (FDL) tendon. These are paired with an elongated EDL and attenuated dorsal capsule. Constant pressure at the lateral nail and digital skin creates pain. INDICATIONSSection 3 of 10
Hard and soft corns Surgical correction is indicated for chronically painful cases in which conservative treatment fails. Patients with neuropathies may also choose surgery or prophylaxis to treat chronic lesions. Hammer, overlapping, or underlapping toes Surgical correction is indicated for progressively painful deformities if conservative treatment fails. RELEVANT ANATOMYSection 4 of 10
Three bones make up the fifth toe. These are the distal, middle, and proximal phalanges. They articulate together to make the DIPJ and PIPJ. The proximal phalanx then articulates with the fifth metatarsal to make the fifth MTPJ. Medial and lateral condyles are present at the base of each phalanx, and epicondyles are present at the heads of the proximal and middle condyles. A 2-boned fifth toe has been reported in 37-76% of the population and involves a union of the distal and middle phalanges. When this occurs, the fifth toe is less flexible and unable to accommodate pressure from shoes and a normal digit. This toe is therefore more susceptible to irritation and development of a painful deformity. The MTPJ has an extensor wing-and-sling mechanism that aids in extension of the digit. A slip of the EDL to the fifth toe travels deep to the extensor wing and sling to insert into the dorsal aspect of the distal phalanx. No slip occurs from the extensor digitorum brevis to the fifth toe; however, an occasional anomaly takes place in which an offshoot from the peroneus brevis tendon travels distal to insert into the dorsal lateral aspect of the fifth MTPJ. The fourth lumbrical muscle inserts into the planter medial fibers of the extensor wing to help abduct and extend the proximal phalanx. The intrinsic third plantar interosseous and flexor digiti quinti brevis muscles insert into the plantar medial and lateral aspects of the proximal phalanx respectively and function to stabilize the MTPJ against the stronger extrinsic FDL and EDL. The abductor digiti minimi muscle originates from the calcaneus and inserts into the plantar lateral aspect of the proximal phalanx to place an abductory force on the toe. The last 2 muscles to affect the fifth digit are the FDL and flexor digitorum brevis (FDB); both plantarflex the toe. The FDL is deep to the FDB until the PIPJ where the FDB splits, allowing the FDL to become superficial and continue distally to insert into plantar portion of the distal phalanx. The FDB then rejoins to insert into the plantar aspect of the middle phalanx. CONTRAINDICATIONSSection 5 of 10
Contraindications for surgery include adequate control with conservative treatment, poor circulation, underlying infection, or any systemic condition that would inhibit healing of the surgical site. WORKUPSection 6 of 10
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TREATMENTSection 7 of 10
Medical therapyMedical therapy is commonly considered conservative care. Conservative treatment for hard corns and soft corns involves periodic shaving by a health care professional using a scalpel or paring device. This is reinforced by regular use of a pumice stone or callus file during or after bathing. Protective padding can be used over hard corns to decrease shoe irritation, and toe spacers are available to ease pressure on soft corns. To decrease pressure, multiple devices such as gel pads, foam, felt, devices with cutouts to accommodate lesions, and moleskin are available over the counter. Wearing wider shoes is a simple way to decrease pressure placed on hammertoes or other rotational deformities. Modifying and stretching the shoes can accomplish the same goals. Surgical therapySurgical therapy depends on the type and level of the deformity. One must determine the underlying pathology and the degree of bone and soft tissue involvement. Angular deformities can be corrected with a combination of bone cuts and derotational skin incisions. Areas with contracted skin or tendons may require lengthening procedures and/or tenotomy. Hard corns Hard corns are probably the most common fifth-toe deformities and yield the most options for treatment. These lesions occur most frequently on the dorsum of the PIPJ as a result of a hammertoe deformity or on the dorsolateral aspect of the PIPJ due to a hammertoe with varus rotation. Corrective procedures include partial condylectomy, exostectomy, hemiphalangectomy, PIPJ arthroplasty with resection of the proximal phalangeal head, or a combination of these. A derotational skin plasty is often included for the varus-rotated toe, and a flexor tenotomy or extensor lengthening can be included for a straight hammertoe deformity. Soft corns Surgical correction for soft corns involves resection of the appropriate bony prominence. This usually involves a combination of condyles from the fourth and fifth digits. A rotational deformity may also be present in the fifth toe, which should be addressed. Typical combinations are (1) resection of the lateral condyle on the base of the fourth toe proximal phalanx and the medial condyle on the head of the fifth toe proximal phalanx or (2) resection of the prominent condyles at the lateral aspect of the fourth PIPJ and the medial aspect of the fifth DIPJ. Web space incisions should be avoided to prevent infections and painful scarring. Hammertoe, claw-toe, cock-up fifth-toe deformities Surgical approaches vary depending on the severity of a deformity. The simplest hammertoe is one that is completely reducible with no bony obstruction to straightening. This is clinically determined by manually straightening the toe. If a very mild deformity is completely reducible, a soft tissue procedure with proper splinting of the digit may be all that is needed for correction. Examples of these are extensor tendon lengthening, dorsal MTPJ capsulotomy, and flexor tendon release. PIPJ arthroplasty is added to the soft tissue releases in more advanced cases that are semireducible or nonreducible. Most surgeons favor PIPJ arthroplasty as a primary procedure because it resolves a contracted PIPJ and functionally lengthens the extensor and flexor tendons, decompressing the MTPJ and DIPJ. After this is performed, the foot is put into a simulated weight-bearing position by pushing up on the fifth metatarsal head. The dorsal contracture at the MTPJ should resolve, and the toe should straighten. If residual contracture at the MTPJ is present, dorsal capsulotomy is performed and lengthening the extensor tendon should be considered. Arthrodesis is described for correction of hammertoes but should not be performed in the fifth digit because it leaves the toe too straight, which causes irritation when wearing shoes. The Ruiz-Mora and syndactylization procedures are commonly described salvage options for severe or recurrent cock-up fifth-toe deformities. The original Ruiz-Mora procedure involved removing the entire proximal phalanx, which left the toe somewhat shortened and unstable. Janecki described the modification that is more commonly used today and calls for a subtotal proximal phalangectomy. Patients should be advised that a good deal of shortening occurs, which may not be cosmetically appealing. The initial step of the Ruiz-Mora procedure is the removal of an ellipse of skin plantar to the proximal phalanx curving slightly medial at the proximal margin of the incision. The flexor tendons are dissected and retracted to expose the PIPJ. A transverse capsulotomy is performed, the collateral ligaments are released, and a subtotal phalangectomy is performed at the head of the proximal phalanx. If a large portion of the bone is removed, the flexor and extensor tendons are held together with purse-string sutures with 2-0 nonabsorbable material. The skin is closed in such a manner that allows the toe to be corrected in a plantar-medial direction. Complications of the Ruiz-Mora procedure include instability of the toe, fourth digit hammertoe formation, callus formation, and bunionette deformity. The patient is allowed to ambulate postoperatively in a stiff-soled shoe, and the toe is splinted or taped in the corrected position for 6 weeks. Syndactylization of the fifth toe to the fourth is generally reserved as a salvage procedure or to resolve a painfully fibrosed web-space lesion secondary to long-standing soft corns. Syndactylization provides excellent stability for an unstable or flail fifth toe. With this procedure, the skin incisions on the fourth and fifth toes should be mirror images of each other. A good technique is to scribe the initial incision on the fifth digit with a surgical pen and then press the 2 digits together where they are to be joined. The ink is transferred to the fourth digit in the precise area where the incision should be placed. The island of tissue created with the incision is carefully dissected to remove only the skin and to leave the subcutaneous tissue intact. Meticulous hemostasis is practiced, and a needle-tipped electrocautery device should be used for precision. Bone work and isolated tendon balancing can be performed through the open sulcus if needed. The skin is closed by placing all of the sutures throughout the site prior to tying the knots. This allows easier and more accurate passing of the needle through the skin margins of the toes. Sutures are left in for 1 extra week (3 wk total), and the digits are splinted for an additional 2-3 weeks. Underlapping and overlapping fifth-toe deformities Many procedures have been described for the correction of an overlapping fifth toe. The deformities range from moderate to more severe, and the procedure chosen should address the existing contractures. The surgical treatment often includes (1) lengthening the contracted skin and tendon and releasing the tight capsular structures and (2) resection of redundant skin and soft tissue. Osseous contractures, if present, also need to be addressed by performing ostectomy and/or arthroplasty. The DuVries procedure is indicated for correcting a mildly overlapping fifth toe. The area over the fourth interspace is longitudinally incised from the base of the toe to just proximal to the fifth metatarsal head. The MTPJ contractures are released via medial capsulotomy and release of the medial collateral ligament. The EDL tendon is then released or lengthened to achieve the final release. The toe is placed into an overcorrected plantar and lateral position, and the skin is closed in this orientation. Dog ears are removed when they occur. Wilson described a modification to the procedure incorporating a V-Y skin advancement to lengthen the contracted skin dorsomedially. Similar releases of the capsule and tendon are performed through the V-Y incision to complete the procedure. The authors use a Z-plasty advancement technique to lengthen the contracted skin dorsomedially. This allows for greater lengthening potential, and the results are more cosmetically appealing than without the modification. PIPJ arthroplasty with appropriate capsule balancing completes the procedure, resulting in an excellent correction. Lapidus described using a tendon transfer to correct severely overlapping fifth toes. He transferred the EDL under the MTPJ and into the abductor digiti quinti. Other modifications have been described including transfer of the EDL into the metatarsal neck, Z-plasty, dorsal capsulotomy with plantar capsulorraphy, and PIPJ arthroplasty. When possible, extensive dissection should be avoided because the toes tend to become postoperatively edematous, leading to pain and difficulty fitting shoes. Underlapping fifth toes typically have a contracted plantar MTPJ capsule and FDL with an attenuated EDL and a redundant dorsal MTPJ capsule. Underlapping fifth toes are usually flexible deformities in the pediatric population; tenotomy at the FDL and FDB with appropriate splinting typically offers good results. However, as with the other conditions mentioned, the degree of deformity must be accounted for, and the appropriate adjunct procedures should be performed. The Thompson technique is widely used and offers good results. Thompson described a Z-type incision over the proximal phalanx with the distal limb laterally oriented and the proximal limb medially oriented. Dissection extends to the PIPJ, where the head of the proximal phalanx is freed of soft tissue attachments and resected using a microsagittal saw. The amount of head resection depends on the severity of the deformity, but care should be taken not to remove too much because this makes the toe unstable. The soft tissue is appropriately augmented, the toe is derotated, and the flexor and extensor tendons are held together with purse-string sutures by using 2-0 nonabsorbable material. In less severe deformities, the purse-string suture can be left out and the capsule simply closed in a standard fashion. Adding a K-wire across the PIPJ for 3-4 weeks or splinting with dressings for the same period can provide stability. Lastly, the Z-incision is reversed and closed using 4-0 nylon. A variation of the Thompson procedure involves a derotational skin plasty by creating a tissue island with a converging semielliptical incision over the PIPJ oriented from distal-dorsal-medial to proximal-plantar-lateral. As with the other procedures, the patient is allowed to ambulate in a postoperative shoe and is gradually transitioned to a roomy athletic-style shoe. The toe should be splinted in the corrected position for 6 weeks. Follow-upFor excellent patient education resources, visit eMedicine's Foot Care Center. Also, see eMedicine's patient education article Corns and Calluses. COMPLICATIONSSection 8 of 10
The most common complication involving fifth-toe procedures is the development of a flail toe. Other potential problems include vascular embarrassment, undercorrection, recurrence, and prolonged edema. Meticulous dissection and tissue handling are the best defenses against vascular problems or prolonged edema. Proper planning should decrease the chance of recurrence or undercorrection. MULTIMEDIASection 9 of 10
REFERENCESSection 10 of 10
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