eMedicine Specialties > Orthopedic Surgery > Hand & Upper Extremity

Syndactyly

E Gene Deune, MD, Associate Professor of Orthopedic Surgery, Associate Professor of Plastic Surgery, Co-Director, Division of Hand Surgery, Director, Hand Surgery Section and Pediatric Hand Surgery, Johns Hopkins University School of Medicine

Updated: Feb 5, 2009

Introduction

Syndactyly is the most common congenital malformation of the limbs, with an incidence of 1 in 2000-3000 live births.^1,2 Syndactyly can be classified as simple when it involves soft tissues only and classified as complex when it involves the bone or nail of adjacent fingers. It is a shared feature of more than 28 syndromes, including Poland, Apert, and Holt-Oram syndromes.  Syndactyly is a failure of differentiation in which the fingers fail to separate into individual appendages. This separation usually occurs during the sixth and eighth weeks of embryologic development. The root words of the term syndactyly are derived from the Greek words syn, meaning together, and dactyly, meaning fingers or digits.

Classification

Classification of syndactyly is based on the severity of the clinical presentation.

• The mildest form is simple syndactyly, which refers to fingers joined only by soft tissue.
• Incomplete simple syndactyly is when the soft-tissue union is only partial and does not extend to the fingertips (see Images 1-2).
• When the soft tissue union extends to the fingertip, the condition is referred to as complete simple syndactyly (see Images 3-4).
• Complex syndactyly refers to fingers joined by bone or cartilaginous union, usually in a side-to-side fashion at the distal phalanges.
• The most severe form is classified as complicated syndactyly, which refers to fingers joined by bony fusion other than a side-to-side fashion and can include bony abnormalities, such as extra, missing, or duplicated phalanges and abnormally shaped bones, such as delta phalanges (see Image 11). Abnormalities in the musculotendinous and neurovascular structures may also be present.

In simple syndactyly, the third web space between the long finger and the ring finger is the area most commonly involved, followed by the fourth, second, and (rarely) first web spaces. Bilateral involvement is found in 50% of patients.

Syndactyly can be an isolated finding, or it can be found in association other abnormalities, such as polydactyly, cleft hands, ring constrictions, or craniofacial syndromes (e.g., Apert syndrome).³

(Images 1 and 2) Dorsal view of a hand demonstrating simple incomplete syndactyly between the left long finger and ring finger. Note the incidental café-au-lait spot.

(Images 1 and 2) Palmar view of the same hand with syndactyly. The level of the syndactyly, just proximal to the proximal interphalangeal (PIP) joint, can be clearly seen on the palmar view.

(Images 3 and 4) Dorsal view of the hand of a 1-year-old child with a complete simple syndactyly. Note that both the long finger and the ring finger have distinct nail plates with a trough separating them.

(Images 3 and 4) Palmar view of the hand of a 1-year-old child with a complete simple syndactyly.

Radiograph of the left hand of a patient with Apert syndrome (type III). Note the complicated syndactyly with osseous union in the distal phalanges of all the fingers. Symphalangism is present between the proximal and middle phalanges, without the formation of a proximal interphalangeal (PIP) joint in the ring, long, and index fingers.

Associated Syndromes

Syndactyly often can be associated with other syndromes, particularly the craniofacial syndromes, of which Apert syndrome is the best known. Another syndrome is Poland syndrome, in which the pectoralis muscle abnormality is found in association with symbrachydactyly and/or other anomalies of the ipsilateral upper extremity.⁴ Constriction band syndrome can be associated with syndactyly, but the etiology of the syndactyly is different.

Apert syndrome

Apert syndrome, or acrocephalosyndactyly, is a rare anomaly, occurring in 1 per 160,000-200,000 live births.^5,6 Besides the characteristic facial anomalies of Apert syndrome, it is also defined by the associated upper- and lower-limb anomalies. The anomalies in the hands are mirror images of each other and are characterized by the following 4 common features: (1) radial deviation of a short thumb as a result of an abnormally shaped proximal phalanx (ie, delta phalanx); (2) complex syndactyly of the index, long, and ring fingers; (3) symbrachyphalangism of the central segments of the index, long, ring, and small fingers; and (4) simple syndactyly of the web space between the ring and small fingers.

The web space between the thumb and the index finger is variable, and the extent of syndactyly at this web space serves as the basis for the classification of Apert syndactyly into 3 types:

• Type I is the most common and the least severe of the three types.  The thumb is foreshortened and associated with a radial clinodactyly as a result of a delta phalanx of the proximal phalanx. Although it is separate from the index finger, the first web space is shallow.  A complex syndactyly includes the index, long, and ring fingers because of osseous or cartilaginous union of the distal phalanges. Simple syndactyly of the small and ring fingers is present; this syndactyly may be complete or incomplete. The distal interphalangeal joint of the small finger is well formed and functional. Type I hands are often referred to as spade hands (see Images 5-7).
• Type II is more severe and is characterized by a simple incomplete or complete syndactyly of the thumb with the index ray, without any osseous union. The thumbnail matrix remains separate from the index fingernail. The hand has a large, concave palm. The bony union of the distal phalanges of the index, long, and ring fingers are more extensive than in type I.  The ring finger–small finger syndactyly remains simple but complete.  Type II hands have been referred to as mitten hands or spoon hands. (see Image 8).
• Type III is the most severe form and, fortunately, the least common. A tight osseous or cartilaginous union is present between all 5 fingers.  All 5 nailplates are conjoined, and they sometimes have longitudinal ridges, which indicate separate underlying distal phalanges. The thumb is indistinguishable from the index ray.  The small finger, although joined by a common fingernail, does not have an osseous union at the distal phalanx and remains a simple but complete syndactyly. Usually, metacarpal synostosis of the small and ring finger rays is present. Type III hands have been termed rosebud or hoof hands (see Images 9-10). Radiographs are difficult to obtain and interpret because of the overlap of osseous structures (see Image 11).⁵

As stated, the goal of treating complex syndactyly is the surgical release of the fingers to increase the functionality of the hand. Timing of the surgery is critical because the child requires multiple operations for other abnormalities of the cranium, midface, and orbits associated with Apert syndrome.

Apert type II hand. Note the complete syndactyly between the ring and the small fingers. The patient's hand was complicated by a chronic paronychia and skin maceration preoperatively.

Apert syndrome (type III), dorsal view.

Apert syndrome (type III), volar view.

The syndactyly found in constriction band syndrome (also known as amniotic band syndrome) is not the result of failure of differentiation during embryogenesis.  In this condition, the fingers are already formed, and because of the injuries due to the constricting amniotic bands, the fingers heal together at the site of injury, causing postinjury syndactyly.⁷ The extent of involvement may be mild, with only a rudimentary small skin bridge connecting the 2 fingers (see Images 16-18), or may be more severe, with a complete soft-tissue fusion in association with amputated fingers (see Images 19-21).

Occasionally, epithelialized sinuses or fistula tracts can be found usually proximal to the level of the syndactyly (see Images 16-18). The finger distal to the constriction ring is usually atrophic, or it has been amputated in utero as a result of ischemia. These findings in the fingers may be isolated or in association with other constrictions on the proximal arm, leg, or face.

If the syndactyly is minimal, standard techniques and skin grafts may be used to release the syndactyly (see Image 22).  If sinus tracts or fistulas exist within the syndactyly, these tracts can often be released to reveal epithelialized web spaces, which do not require skin grafts (see Image 23). The markings made prior to the syndactyly then require modification.

Problem

Unreleased syndactyly can significantly impair finger and hand function. The impairment is worse when the syndactyly is complete, is complex, or involves the border digits with fingers of uneven lengths, such as the ring and small fingers or the thumb and index finger (see Image 24).

(Images 24 and 25) Complete simple syndactyly of the ring and small fingers. Note the ring finger proximal interphalangeal (PIP) joint flexion deformity due to the complete syndactyly between the border digits.

(Images 24 and 25) Complete simple ring and small finger syndactyly. Note the ulnar deviation of the ring finger due to the syndactyly of the small finger.

Frequency

Syndactyly is the most common congenital abnormality of the hand, with a rate of 1 per 2000-3000 births.^8,9,10,11 The male-to-female ratio is 2:1.

Etiology

Approximately 10-40% of cases are familial with variable penetrance.  Syndactyly can occur as part of a syndrome or as sporadic events that are nonhereditary and nonsyndromic. One report indicates that there is an association of syndactyly with smoking during pregnancy.¹²

Presentation

Although many patients with syndactyly have been evaluated by multiple specialists and referred by their primary care pediatrician, the hand surgeon should also obtain a thorough prenatal, postnatal, and familial history. In addition to the hand being examined, the cranium, face, torso, and lower extremities should be examined for anomalies.

The hand evaluation should proceed systematically.

• Note and document the number of digits present, the level of web involvement, the length of the finger, and the appearance of the fingernails.
• Often, photographing or drawing a picture of the hands during the initial visit is helpful.
• Passively move the fingers to determine bony union; differential motion occurs only if no underlying bony union is present. Fusions of the fingernails often are associated with bony union, and a broad fingernail also may indicate a hidden polydactyly.
• The extent of anomaly of tendons and neurovascular structures reflects the complexity of the syndactyly. In a simple complete or a complex syndactyly involving only the distal phalanx, the underlying tendon and neurovascular structures are usually normal. However, in an individual with brachysyndactyly or complicated syndactyly, the bifurcation of the nerves and digital vessels may be located more distally, or only one side may be present.
• Always obtain radiographs to help identify any other anomalies, such as bony synostosis, a delta phalanx, or symphalangism.

Indications

In itself, a minor incomplete syndactyly is not an indication for surgery if the only issue is its incongruous appearance. However, a syndactyly that prevents full range of motion in the involved fingers warrants surgical release to increase functionality of the fingers. (see Images 24-25).  As with any operation, exceptions to the rule exist (see Contraindications).

Contraindications

Workup

Imaging Studies

• Obtain radiographs of the hands to evaluate for any other bony anomalies, such as synostosis, delta phalanx, or symphalangism.

Diagnostic Procedures

If the infant has no associated medical conditions, a formal preoperative evaluation by the anesthesia team is usually not necessary.  However, should there be any congenital syndromes or associated medical conditions, the patients should be scheduled for operative clearance with the preoperative evaluation service of the hospital where the surgery will be done.  Generally, if there is no issue with postoperative monitoring, many of these cases can be handled as outpatient procedures.

Treatment

Medical Therapy

Syndactyly requires surgical intervention. Full-term infants can be scheduled for elective surgical procedures as early as 5 or 6 months of age. Surgery before this age can increase anesthetic risks. Prior to that time, there is generally no intervention necessary if there are no problems. If there is an associated paronychia (see Image 26), which can occur with complex syndactyly, the parents are given instructions to wash the child's hands thoroughly with soap and water and to apply a topical antibacterial solution or ointment. Oral antibiotics are given when indicated.

Paronychia in a patient with Apert syndrome. Despite the use of oral antibiotics and topical antibiotic solution, the paronychia did not fully resolve until the fingers were divided.

Surgical Therapy

The timing of surgery is variable. However, if more fingers are involved and the syndactyly is more complex, release should be performed earlier. Early release can prevent the malrotation and angulation that develops from differential growth rates of the involved fingers.

In persons with complex syndactyly, the author performs the first release of the border digits when the individual is approximately 6 months old. This approach is used because differential growth rates are observed, particularly between the small finger and ring finger or between the thumb and index finger. Prolonged syndactyly between these digits can cause permanent deformities. If more than one syndactyly is present in the same hand, simultaneous surgical release can be performed, provided only one side of the involved fingers is released. For example, in a 4-finger syndactyly involving the index, long, ring, and small fingers, the index finger can be released from the long finger, and the small finger can be released from the ring finger, leaving a central syndactyly involving the long and ring fingers (see Images 27-28). If both hands are involved, bilateral releases can be performed at one  operative  setting.

(Images 27-30) Left hand of a patient with Apert syndrome type II. The hand has already undergone a previous first-stage division. Bilateral releases were simultaneously performed to release the border digits along with deepening of the 1st webspaces using a 4-flap z-plasty.

(Images 27-30) Volar view of the left hand of a patient with Apert syndrome type II. The hand has already undergone first-stage division. Bilateral releases were simultaneously performed to release the border digits along with deepening of the 1st webspaces using a 4-flap z-plasty.

(Images 27-30) Left hand of a patient with Apert syndrome type II. This is a 6-month postoperative picture after second-stage release was performed for the central digits between the long finger and ring finger. Surgical release was performed with the standard zigzag incisions. Soft-tissue coverage for the phalanges was sufficient after the release; therefore, a pedicle groin flap was not needed. The long finger and ring finger shared a conjoint nail, which was also released successfully. This picture was taken during subsequent surgical revision of a tracheostomy.

(Images 27-30) Dorsal view of the left hand of a patient with Apert syndrome type II. This is a 6-month postoperative picture obtained after a second-stage release was performed for the central digits between the long finger and ring finger. Surgical release was performed with the standard zigzag incisions. Soft-tissue coverage for the phalanges was sufficient after the release; therefore, a pedicle groin flap was not needed. The long finger and ring finger shared a conjoint nail, which was also released successfully. This picture was taken during subsequent surgical revision of a tracheostomy.

However, even if the child is older than the ideal age (which is usually before school age for functional, developmental, and psychological reasons), it is not too late to release the central rays (long and ring fingers) at a later age, as they have similar growth rates. For example, a 5° flexion contracture could eventually improve once the fingers are released. In children, unlike in adults, persistent flexion contractures are rare. The technical details of syndactyly release are similar to the release performed in infants.  In older patients, splints are still applied but can be removed earlier, at about 7-10 days, because the patients are more compliant with activity and with dressing changes after the splint is removed.¹³

Preoperative Details

The parents are instructed to bathe the patient on the morning of surgery, with particular instructions to wash the hands and the groin region where the skin graft will be harvested.

Intraoperative Details

Surgical technique

With any initial syndactyly release, operate on only 1 side of the finger at any particular time to prevent ischemic compromise to the finger should one of the digital vessels be absent or be injured. The surgical division is individually tailored based on complexity and location of the syndactyly. Generally, the release is accomplished by dividing the fingers and resurfacing the surgical wound with a well-vascularized dorsal trapezoidal-shaped flap, interdigitating fasciocutaneous flaps, and full-thickness skin grafts to resurface interdigital space (see Images 31-34). The web is reconstructed with a well-vascularized dorsal fasciocutaneous flap.¹⁴

(Images 31-34) Dorsal view of the hand of a 1-year-old patient with complete simple syndactyly between his long finger and ring finger. The typical zigzag incisions are marked on both the dorsal and volar surfaces. Note the length of the dorsal trapezoidal flap design. Because it needs to be inset at a 45° angle with the distal edge of the web at the midlevel of the proximal phalanges, the length of the flap needs to be long enough to achieve this goal.

(Images 31-34) Volar view of the hand of a 1-year-old patient with complete simple syndactyly between his long finger and ring finger. The typical zigzag incisions are marked on both the dorsal and volar surfaces. Note the length of the dorsal trapezoidal flap design. Because it needs to be inset at a 45° angle with the distal edge of the web at the midlevel of the proximal phalanges, the length of the flap needs to be long enough to achieve this goal. Note the incidental simian crease.

(Images 31-34) Hand of a 1-year-old patient with complete simple syndactyly between his long finger and ring finger. This picture was takenimmediately after the procedure. On the dorsal view, note the proximal skin graft on the ulnar and radial sides of the dorsal trapezoidal flap.

(Images 31-34) Hand of a 1-year-old patient with complete simple syndactyly between his long finger and ring finger. This picture was taken immediately after the procedure.

Inform the parents that skin grafts are needed for all cases except for the most minor of incomplete simple syndactyly (eg, those that are located in the first web space between the thumb and the index finger). For incomplete simple syndactyly, various techniques, such as double-opposing Z-plasty or a 4-flap Z-plasty, may not require skin grafts (see Images 35-41). Many variations and techniques have been devised for syndactyly release, and Upton has reviewed their descriptions and their history.¹⁵

Regardless of the techniques used, the following general principles must be applied to achieve optimal results:

• Use loupe magnification (2.5X or greater).
• Use zigzag lines to distribute the lines of contraction; avoid straight lines.
• Use well-vascularized flaps to reconstruct the web space.
• Defatting of the interdigital space should be judicious; otherwise, the neurovascular pedicles may be injured.
• Release only 1 side of a finger at a time during the initial syndactyly release, and whenever possible, perform bilateral syndactyly releases, particularly in children younger than 18 months, when bilateral surgeries are well tolerated.
• Harvest full-thickness skin grafts from a hairless region that has a reasonable color match.
• A tourniquet is crucial in the dissection to achieve a bloodless field to avoid damage to the neurovascular structures.
• Achieve hemostasis in the wound base to optimize survival of the skin graft.
• Use only absorbable sutures, such as 5-0 mild chromic catgut or synthetic rapidly absorbable sutures, which may cause less inflammation.

Skin grafts

Full-thickness skin grafts are preferable over split-thickness skin grafts because the former are less likely to contract over time and because they usually grow with the patient. The most common full-thickness skin-graft donor site is the lateral inguinal region close to the anterior superior iliac crest. This area is generally hairless, even in the hirsute adult. The skin is taken as an ellipse, and the donor site is closed primarily. Morbidity associated with this donor site, particularly the infection rate, is low. The incision heals nicely and is usually inconspicuous (see Image 42).

Skin-graft donor site. The donor site in the right inguinal region has healed well 10 months after the patient's syndactyly surgery. The graft harvested was able to resurface 2 web spaces during bilateral web-space releases. The incision is inconspicuous.

Postoperative Details

A well-molded bulky dressing is applied to the upper extremity. A generous amount of antibiotic ointment is directly applied to the skin graft, and the incisions are followed by a nonadherent dressing material such as Adaptik. (Petroleum-impregnated cotton gauze products tend to dry quickly and can become adherent to the skin grafts with the first dressing change, so the surgeon may want to avoid this.) This step is followed by gently laying cotton fluffs within the web space. The upper extremity is then placed into a well-padded, long-arm bulky dressing, which is reinforced with a long-arm fiberglass splint. The skin-graft donor site is closed with absorbable sutures and steristrips and covered with gauze and clear cellophane adhesive.¹⁷

The parents are instructed to remove the skin-graft donor site dressing on postoperative day 3.  They may then start bathing the child and can get the donor site wet, with encouragement to wash this area with soap and water. The long arm splint is kept in place and is removed at 2 weeks. Utmost care should be taken when the dressing is removed. If there is any concern about the possibility of loss of the skin graft with an early dressing change at 2 weeks, the dressing is left in place for 3 weeks.

The dressing is removed intraoperatively if any concern exists about the child being unable to tolerate a dressing change in the office. After this, the parents are instructed to do daily wound care. Instruct the parents to gently wash their hands before changing each dressing and to change the dressing once a day for 2 weeks. During these changes, an antibiotic ointment should be applied with a cotton swab to gently agitate any dried blood or residual drainage that is adhering to the sutures. The web spaces are dressed with 2 × 2 cotton gauze, laid into the web space to prevent scar adhesions and synechiae. This dressing is then reinforced with 2-in gauze.
 
Stockinnettes are then applied over the arms and secured to the patient's shirt at the shoulder with safety pins to prevent the patient from chewing or taking the dressing off. If the bandages stick to the sutures or to the wound, the parents are instructed to pour warm water with peroxide as needed to lift the dressing off atraumatically. The parents are instructed about scar management starting 6 weeks after surgery.

Follow-up

At the time of the first dressing change, the skin graft has become adherent, and the child may start to use his or her fingers as tolerated, although the parents are instructed to place a stockinnette over the arm to prevent the child from inadvertently contaminating and injuring the site.

The author usually waits for 6 months before performing the next syndactyly release or revision.

Complications

Complications of syndactyly release include recurrence of syndactyly, finger ischemia, contracture, and various skin-graft complications.

Recurrence of syndactyly

Distal migration of the web (i.e., web creep) can occur, even after successful release. The incidence is reported to be in the range of 7.5-60%.^8,18,19

The causes are multifactorial. If recurrence appears early, it is usually the result of the presence of synechiae between the incision lines and, most likely, poor take of the skin graft. Because of this, making certain that the interdigital spaces remain separated is important in the early postoperative period. Also, it is important to create a dorsal flap that is well vascularized at the tip, where it will be sutured to the base of the web. The flap is important in providing tissue that has skin elasticity that with adapt with the growth of the finger. Skin-graft loss also can contribute to web creep by increasing the possibility of scar contracture.

However, the major reason why web creep occurs is the discrepant growth rates between the scar and the surrounding tissue, leading to the appearance of an incomplete simple syndactyly. Depending on the severity of the web creep (see Image 43), further release, as well as skin grafting, may be necessary. If left untreated, angulation and malrotation can occur.

Hand of a 23-year-old patient who underwent releases of simple complete syndactyly of both the left third and fourth web spaces as an infant. The patient noticed progressive shortening of the web space and found it hard to wear protective gloves, necessary for employment in the fishing industry. This resulted in a poor fit of the glove and chronic irritation of the web. Note the radial deviation of the small finger due to the contracture from the patient's first surgery. The web space was deepened with local flaps and full-thickness skin grafts from the left groin.

Finger ischemia

Although rare, finger ischemia can occur if a developmental anomaly with the digital vessels is present or if a digital vessel is damaged. This is why only 1 side of the finger should be operated on during initial syndactyly release.

Contracture

Occasionally, despite the best effort and well-planned flaps, a contracture develops along the length of the incision line. This can result in a scar contracture and angulation of the finger. To prevent further angulation, a Z-plasty or skin graft will be needed to release this contracture (see Images 44-49).

Scar contractures often develop in the web space within the first 6 months, making the webs more shallow, even if no skin-graft loss has occurred and if the design of the flaps is correct. The author usually recommends that the parents massage the webs to help with scar remodeling. Parents are also encouraged to place elastic bandages (such as Coban bandages) in the webs to stretch them. The judicious use of steroid creams can also help with tight scars.

Skin-graft complications

Partial skin-graft loss results in an open wound that heals by secondary intention. As in any wound that heals by secondary intention, the contracture forces are great. The deforming forces can be so great that they produce angulation of the fingers, which requires further corrective surgery. Having complete hemostasis in the wound base prior to the application of the skin graft is extremely important, as is securely sewing the skin graft. Proper postoperative dressings are also important to the success of the skin graft.

Because of the zigzag incisions and the need for skin grafts, the finger has a patchwork appearance. In a light-colored individual, this difference is not noticeable. However, in a patient who has medium-to-dark pigmentation, spears or islands of pigmented skin in the usually nonpigmented palmar surface can be the result (see Images 50-51).²⁰ To avoid this effect, nonpigmented skin grafts may be harvested from either the plantar surfaces of the feet or hypothenar regions of the hands.

Hand of an 18-year-old patient of Mediterranean heritage who had undergone multiple syndactyly releases with a full-thickness skin graft harvested from the groin as an infant. The skin graft can be observed as hyperpigmented patches within the web space. Some parts of the full-thickness skin graft also were noted to be hair bearing. Parents should be informed of the potential sequelae of the full-thickness skin grafts as the infant matures.

Hand of an 18-year-old woman of Middle Eastern heritage who had undergone multiple syndactyly releases with a full-thickness skin graft harvested from her groin when she was an infant. The skin graft can be observed as hyperpigmented patches within the web space. Some parts of the full-thickness skin graft were also noted to be hair bearing. Parents should be informed of the potential sequelae of the full-thickness skin grafts as the infant matures.

Outcome and Prognosis

Despite appearing relatively straightforward, syndactyly release is a complex operation requiring well-honed skills. If properly performed, the rate of complications is low, and the results are extremely gratifying for the parents and beneficial to the patients in improving hand functionality and in providing normal-appearing hands and fingers.

Multimedia

Media file 1: (Images 1 and 2) Dorsal view of a hand demonstrating simple incomplete syndactyly between the left long finger and ring finger. Note the incidental café-au-lait spot.

Media file 2: (Images 1 and 2) Palmar view of the same hand with syndactyly. The level of the syndactyly, just proximal to the proximal interphalangeal (PIP) joint, can be clearly seen on the palmar view.

Media file 3: (Images 3 and 4) Dorsal view of the hand of a 1-year-old child with a complete simple syndactyly. Note that both the long finger and the ring finger have distinct nail plates with a trough separating them.

Media file 4: (Images 3 and 4) Palmar view of the hand of a 1-year-old child with a complete simple syndactyly.

Media file 5: (Images 5-7) Dorsal view of hand of a 6-month-old patient with type I Apert syndrome. Note that the thumb is separate.

Media file 6: (Images 5-7) Radial view of hand of a 6-month-old patient with type I Apert syndrome. The index fingernail is separate, and the syndactyly is complete. The small fingernail is also separate from the rest of the hand. A simple syndactyly between the small finger and the rest of the hand is present. Note that the broad thumb and the abnormal curvature of the thumb is due to the presence of a delta phalanx seen in the x-ray below.

Media file 7: (Images 5-7) Radiograph of hand of the 6-month-old patient with type I Apert syndrome demonstrates the distinctive characteristics of Apert syndrome. In the small finger, the distal interphalangeal (DIP) is formed. Although a rudimentary proximal interphalangeal (PIP) joint is present, clinically this joint is stiff. In the ring, long, and index fingers, no PIP joint is present, and symphalangism is present between the middle and the proximal phalanges. The distal phalanges of the ring and long finger are fused. In the thumb, the proximal phalanx is shaped abnormally and is referred to as the delta phalanx. Synostosis of the ring and the small finger metacarpals is present.

Media file 8: Apert type II hand. Note the complete syndactyly between the ring and the small fingers. The patient's hand was complicated by a chronic paronychia and skin maceration preoperatively.

Media file 9: Apert syndrome (type III), dorsal view.

Media file 10: Apert syndrome (type III), volar view.

Media file 11: Radiograph of the left hand of a patient with Apert syndrome (type III). Note the complicated syndactyly with osseous union in the distal phalanges of all the fingers. Symphalangism is present between the proximal and middle phalanges, without the formation of a proximal interphalangeal (PIP) joint in the ring, long, and index fingers.

Media file 12: (Images 12 and 13) Poland Syndrome: Dorsal view of a left hand in a patient with Poland Syndrome with brachydactyly (short fingers) and adactyly (missing fingers) with associated simple incomplete syndactyly between the ring and the small finger

Media file 13: (Images 12 and 13) Volar view of the preceding hand in a patient affected with Poland syndrome.

Media file 14: (Images 14 and 15) Right hand of a patient with Poland syndrome. Note the incomplete syndactyly between the hypoplastic right index and long fingers.

Media file 15: (Images 14 and 15) Volar view of the index and long finger in incomplete syndactyly in a patient with Poland syndrome.

Media file 16: (Images 16-23) Dorsal view of the right hand of a 1.5-year-old patient with constriction band syndrome. The fingers can still be identified individually. Note the presence of a fistula tract between the affected fingers, particularly between the long finger and ring finger.

Media file 17: (Images 16-23) Palmar view of the right hand of a 1.5-year-old patient with constriction band syndrome. The fingers can still be identified individually. Note the presence of a fistula tract between the affected fingers, particularly between the long finger and ring finger.

Media file 18: (Images 16-23) Right hand of a 1.5-year-old patient with constriction band syndrome. Radiograph demonstrates that the level of the amputation occurred at the proximal interphalangeal (PIP) joints.

Media file 19: (Images 16-23) Dorsal view of left hand of a 1.5-year-old patient with constriction band syndrome. The left hand is more severely involved than the right, with all of the fingers being nearly indistinguishable from one another. Note the presence of pits between the fingers where normal webs would be. The most prominent one is between the ring and the small fingers. They often represent fistulas between the dorsal and the volar surface of the hand and are often the only thing remaining of the previous normal web space.

Media file 20: (Images 16-23) Volar view of left hand of a 1.5-year-old patient with constriction band syndrome. The left hand is more severely involved than the right, with all of the fingers being nearly indistinguishable from one another. Note the presence of a prominet fistula between the small finger and ring finger.

Media file 21: (Images 16-23) Radiograph of left hand of a 1.5-year-old patient with constriction band syndrome. The level of amputation is through the midportion of the proximal phalanges of the involved fingers.

Media file 22: (Images 16-23) Image of the left hand of a 1.5-year-old patient with constriction band syndrome after a second reconstructive procedure following release of the second and fourth web spaces. The syndactyly partially recurred because of a skin-graft loss. During the second-stage operation to separate the long finger and ring finger, the recurrence in the second and fourth web spaces were re-revised. Thus, sutures are present on both sides of the ring finger and long finger.

Media file 23: (Images 16-23) Palmar view of the right hand of a 1.5-year-old patient with constriction band syndrome after a previously staged syndactyly release. No skin graft was needed for the release between the long and ring fingers. The patient also underwent revision of the web space between the index and long fingers.

Media file 24: (Images 24 and 25) Complete simple syndactyly of the ring and small fingers. Note the ring finger proximal interphalangeal (PIP) joint flexion deformity due to the complete syndactyly between the border digits.

Media file 25: (Images 24 and 25) Complete simple ring and small finger syndactyly. Note the ulnar deviation of the ring finger due to the syndactyly of the small finger.

Media file 26: Paronychia in a patient with Apert syndrome. Despite the use of oral antibiotics and topical antibiotic solution, the paronychia did not fully resolve until the fingers were divided.

Media file 27: (Images 27-30) Left hand of a patient with Apert syndrome type II. The hand has already undergone a previous first-stage division. Bilateral releases were simultaneously performed to release the border digits along with deepening of the 1st webspaces using a 4-flap z-plasty.

Media file 28: (Images 27-30) Volar view of the left hand of a patient with Apert syndrome type II. The hand has already undergone first-stage division. Bilateral releases were simultaneously performed to release the border digits along with deepening of the 1st webspaces using a 4-flap z-plasty.

Media file 29: (Images 27-30) Left hand of a patient with Apert syndrome type II. This is a 6-month postoperative picture after second-stage release was performed for the central digits between the long finger and ring finger. Surgical release was performed with the standard zigzag incisions. Soft-tissue coverage for the phalanges was sufficient after the release; therefore, a pedicle groin flap was not needed. The long finger and ring finger shared a conjoint nail, which was also released successfully. This picture was taken during subsequent surgical revision of a tracheostomy.

Media file 30: (Images 27-30) Dorsal view of the left hand of a patient with Apert syndrome type II. This is a 6-month postoperative picture obtained after a second-stage release was performed for the central digits between the long finger and ring finger. Surgical release was performed with the standard zigzag incisions. Soft-tissue coverage for the phalanges was sufficient after the release; therefore, a pedicle groin flap was not needed. The long finger and ring finger shared a conjoint nail, which was also released successfully. This picture was taken during subsequent surgical revision of a tracheostomy.

Media file 31: (Images 31-34) Dorsal view of the hand of a 1-year-old patient with complete simple syndactyly between his long finger and ring finger. The typical zigzag incisions are marked on both the dorsal and volar surfaces. Note the length of the dorsal trapezoidal flap design. Because it needs to be inset at a 45° angle with the distal edge of the web at the midlevel of the proximal phalanges, the length of the flap needs to be long enough to achieve this goal.

Media file 32: (Images 31-34) Volar view of the hand of a 1-year-old patient with complete simple syndactyly between his long finger and ring finger. The typical zigzag incisions are marked on both the dorsal and volar surfaces. Note the length of the dorsal trapezoidal flap design. Because it needs to be inset at a 45° angle with the distal edge of the web at the midlevel of the proximal phalanges, the length of the flap needs to be long enough to achieve this goal. Note the incidental simian crease.

Media file 33: (Images 31-34) Hand of a 1-year-old patient with complete simple syndactyly between his long finger and ring finger. This picture was takenimmediately after the procedure. On the dorsal view, note the proximal skin graft on the ulnar and radial sides of the dorsal trapezoidal flap.

Media file 34: (Images 31-34) Hand of a 1-year-old patient with complete simple syndactyly between his long finger and ring finger. This picture was taken immediately after the procedure.

Media file 35: (Images 35-41) Dorsal view of left hand demonstrating a simple incomplete syndactyly between the long finger and ring finger. This incomplete simple syndactyly was released by using a V-to-M flap without the need for a skin graft. Note the markings.

Media file 36: (Images 35-41) Volar view of left hand demonstrates a simple incomplete syndactyly between the long finger and ring finger. Immediate postoperative results are shown. Note the markings.

Media file 37: (Images 35-41) Dorsal view of a left hand demonstrates a simple incomplete syndactyly between the long finger and ring finger. Immediate postoperative results are shown.

Media file 38: (Images 35-41) Immediate postoperative results are shown.

Media file 39: (Images 35-41) Immediate postoperative results are shown.

Media file 40: (Images 35-41) One month later, the hand has a sufficiently deepened web. However, hypertrophic and hyperpigmented scars are still present along the incision line.

Media file 41: (Images 35-41) One month later, the hand has a sufficiently deepened web. However, hypertrophic and hyperpigmented scars are still present along the incision line.

Media file 42: Skin-graft donor site. The donor site in the right inguinal region has healed well 10 months after the patient's syndactyly surgery. The graft harvested was able to resurface 2 web spaces during bilateral web-space releases. The incision is inconspicuous.

Media file 43: Hand of a 23-year-old patient who underwent releases of simple complete syndactyly of both the left third and fourth web spaces as an infant. The patient noticed progressive shortening of the web space and found it hard to wear protective gloves, necessary for employment in the fishing industry. This resulted in a poor fit of the glove and chronic irritation of the web. Note the radial deviation of the small finger due to the contracture from the patient's first surgery. The web space was deepened with local flaps and full-thickness skin grafts from the left groin.

Media file 44: (Images 44-49) Hand of a 26-month-old patient who underwent release of a complete simple syndactyly between the left ring and long fingers with flaps and full-thickness skin grafts at 7 months of age. The patient developed hypertrophic scarring along the incisions. This persisted despite conservative treatment with topical steroid cream and scar massage. Contracture was present mostly along the ring finger, causing tethering of the distal ring finger with a mild radial deviation. The contracture was released with multiple Z-plasties and the web deepened with a small full-thickness skin graft.

Media file 45: (Images 44-49) Hand of a 26-month-old patient with syndactyly who underwent release of a complete simple syndactyly of the left ring finger and long finger with flaps and full-thickness skin graft at 7 months of age. The patient developed hypertrophic scarring along the incisions, which persisted despite conservative treatment with topical steroid cream and scar massage. This contracture was present mostly along the ring finger, causing tethering of the distal ring finger with a mild radial deviation.

Media file 46: (Images 44-49) Hand of a 26-month-old patient who underwent release of a complete simple syndactyly between the left ring and long fingers with flaps and full-thickness skin grafts at 7 months of age. The patient developed hypertrophic scarring along the incisions. This persisted despite conservative treatment with topical steroid cream and scar massage. Contracture was present mostly along the ring finger, causing tethering of the distal ring finger with a mild radial deviation. The contracture was released with multiple Z-plasties and the web deepened with a small full-thickness skin graft.

Media file 47: (Images 44-49) Hand of a 26-month-old patient who underwent release of a complete simple syndactyly between the left ring and long fingers with flaps and full-thickness skin grafts at 7 months of age. The patient developed hypertrophic scarring along the incisions. This persisted despite conservative treatment with topical steroid cream and scar massage. Contracture was present mostly along the ring finger, causing tethering of the distal ring finger with a mild radial deviation. The contracture was released with multiple Z-plasties and the web deepened with a small full-thickness skin graft.

Media file 48: (Images 44-49) Hand of a 26-month-old patient who underwent release of a complete simple syndactyly between the left ring and long fingers with flaps and full-thickness skin grafts at 7 months of age. The patient developed hypertrophic scarring along the incisions. This persisted despite conservative treatment with topical steroid cream and scar massage. Contracture was present mostly along the ring finger, causing tethering of the distal ring finger with a mild radial deviation. The contracture was released with multiple Z-plasties and the web deepened with a small full-thickness skin graft. At 3 months after surgery, he was doing well and had no evidence of recurrence.

Media file 49: (Images 44-49) Hand of a 26-month-old patient who underwent release of a complete simple syndactyly between the left ring and long fingers with flaps and full-thickness skin grafts at 7 months of age. The patient developed hypertrophic scarring along the incisions. This persisted despite conservative treatment with topical steroid cream and scar massage. Contracture was present mostly along the ring finger, causing tethering of the distal ring finger with a mild radial deviation. The contracture was released with multiple Z-plasties and the web deepened with a small full-thickness skin graft. At 3 months after surgery, he was doing well and had no evidence of recurrence.

Media file 50: Hand of an 18-year-old patient of Mediterranean heritage who had undergone multiple syndactyly releases with a full-thickness skin graft harvested from the groin as an infant. The skin graft can be observed as hyperpigmented patches within the web space. Some parts of the full-thickness skin graft also were noted to be hair bearing. Parents should be informed of the potential sequelae of the full-thickness skin grafts as the infant matures.

Media file 51: Hand of an 18-year-old woman of Middle Eastern heritage who had undergone multiple syndactyly releases with a full-thickness skin graft harvested from her groin when she was an infant. The skin graft can be observed as hyperpigmented patches within the web space. Some parts of the full-thickness skin graft were also noted to be hair bearing. Parents should be informed of the potential sequelae of the full-thickness skin grafts as the infant matures.

References

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Keywords

syndactyly, simple syndactyly, incomplete simple syndactyly, complete simple syndactyly, complex syndactyly, complicated syndactyly, type I acrocephalosyndactyly, acrocephalosyndactyly, Apert syndrome, type I Apert syndrome, type II Apert syndrome, type III Apert syndrome, Apert's syndrome, Apert syndactyly, Poland syndrome, constriction band syndrome, polydactyly, cleft hands, ring constrictions, brachysyndactyly, symbrachyphalangisms, spade hands, mitten hands, spoon hands, rosebud hands, hoof hands, Holt-Oram syndrome, congenital hand deformity, congenital syndromes

Contributor Information and Disclosures

Author

E Gene Deune, MD, Associate Professor of Orthopedic Surgery, Associate Professor of Plastic Surgery, Co-Director, Division of Hand Surgery, Director, Hand Surgery Section and Pediatric Hand Surgery, Johns Hopkins University School of Medicine
E Gene Deune, MD is a member of the following medical societies: Alpha Omega Alpha, American Association for Hand Surgery, American Association of Plastic Surgeons, American Society for Reconstructive Microsurgery, American Society of Plastic Surgeons, and Plastic Surgery Research Council
Disclosure: Nothing to disclose.

Medical Editor

A Lee Osterman, MD, Director of Hand Surgery Fellowship, Director, Philadelphia Hand Center; Director, Professor, Department of Orthopedic Surgery, Division of Hand Surgery, University Hospital, Thomas Jefferson University
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Michael Yaszemski, MD, PhD, Associate Professor, Departments of Orthopedic Surgery and Bioengineering, Mayo Foundation, Mayo Medical School
Disclosure: Nothing to disclose.

CME Editor

Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital
Dinesh Patel, MD, FACS is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Association of Physicians of Indian Origin, American College of International Physicians, and American College of Surgeons
Disclosure: Nothing to disclose.

Chief Editor

Harris Gellman, MD, Consulting Surgeon, Broward Hand Center; Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine
Harris Gellman, MD is a member of the following medical societies: American Academy of Medical Acupuncture, American Academy of Orthopaedic Surgeons, American Orthopaedic Association, American Society for Surgery of the Hand, and Arkansas Medical Society
Disclosure: Nothing to disclose.

I would like to thank Dr. William Dahl, MD, who helped compile new references for this revision.

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