Chapter 152. Zipper Injury Management

Zipper injuries frequently occur to the foreskin, the skin of the penis, and the scrotum. Zipper injuries result in skin and soft tissue entrapment when the zipper is opened or closed. It primarily occurs in uncircumcised young boys, intoxicated adults, the mentally handicapped, males not wearing underwear, and elderly men suffering from movement or cognitive disorders. The most common type of zipper entrapment compresses the skin between the sliding piece (fastener mechanism) and the teeth of the zipper. Another type of entrapment involves the skin between the teeth of the zipper after the sliding piece has moved beyond the area.1,2 Multiple methods to extract the entrapped skin have been reported.1–15 These methods range from manipulation to tooth-by-tooth extraction to circumcision. Treatment should be guided by the type of entrapment.1 Removal of the zipper can be performed quickly using basic tools to extract the entrapped tissue and thus prevent or limit secondary injury.

The zipper is a simple device that is used daily by millions of people (Figure 152-1). It consists of a sliding piece that moves in two directions. The sliding piece is composed of a front and back plate connected by the median bar.5 The median bar is usually located at the top of the sliding piece. A finger grip is attached to the front plate of the sliding piece and functions as a handle to move the sliding piece. The teeth are two opposing sets of rectangular metal or plastic pieces attached to fabric to keep them aligned. Moving the sliding piece across an open zipper will interlock the teeth and close the zipper. Reversing the sliding piece direction will unlock the teeth and open the zipper.

Although any area of skin can become entrapped in a zipper, it primarily occurs to the foreskin, penis, and scrotum. Entrapment often occurs in those who are in a rush to get dressed, not wearing underwear, or intoxicated, or in a rush to zip up their pants. Zipper injuries can be extremely painful. Patients are often unable to undo the entrapment themselves and present to the Emergency Department for help. Because this is an embarrassing injury, patients often present after attempts at self-extraction and a few hours after the injury. Delays in seeking medical care may result in significant edema that can complicate the removal of the entrapped tissue.

Skin entrapped between the sliding piece and teeth or between the teeth of the zipper must be extricated. The skin should be released as soon as possible to minimize edema and prevent necrosis.

There are no absolute contraindications to the removal of a zipper, the slider, or the teeth from an entrapped piece of skin. Consult a Urologist after releasing the entrapment in cases of significant edema, skin necrosis, urethral involvement, or infection.

• Heavy-duty wire cutter or bone cutter
• Scissors, bandage or Mayo
• Scissors, small or iris
• Topical anesthetic, e.g., EMLA cream
• Local anesthetic solution without epinephrine
• Mineral oil
• Miniature hacksaw
• 27 gauge needle
• 5 mL syringe

Explain the procedure and aftercare required to the patient and/or their representative. Obtain appropriate consent to perform the procedure. Assess the patient's level of anxiety and pain as they must remain calm during the procedure to avoid secondary injury. The application of a topical anesthetic such as EMLA cream may be helpful but delays extraction of the entrapped skin. If the patient has significant pain, local anesthetic solution can be subcutaneously infiltrated around the entrapped skin or a penile block (Chapter 146) can be performed. The application of parenteral analgesia, sedation, or procedural sedation may be required in rare instances.

Manual Removal

Apply mineral oil liberally to the zipper and entrapped skin. Allow the mineral oil to soak the skin and zipper for approximately 10 minutes. Apply gentle but steady traction on the zipper, away from the entrapped tissue with special care to avoid further injury.9,14,15 Attempt to dislodge the zipper manually. Do not forcefully try to unzip it. Excessive force is unnecessary and can result in avulsions and lacerations to the skin. If this fails to release the tissue, perform one of the zipper disassembly techniques listed below.

Cutting of the Median Bar

The median bar can be cut with a heavy-duty wire cutter or bone cutter.6,7 If the skin is entrapped between the sliding piece and the teeth (Figure 152-2A), carefully cut the median bar (Figure 152-2B). The front and back plates of the zipper will separate and release the entrapped skin (Figure 152-2C). Occasionally, the skin is entrapped between the teeth of the zipper (Figure 152-3). Cut the median bar of the sliding piece to remove the zipper. Manually pull the two rows of teeth apart to release the entrapped skin.

Cutting of the Cloth Surrounding Zipper Teeth

Occasionally, the skin is trapped between the teeth of the zipper and a wire cutter or bone cutter is not available.8 Cut the cloth holding the zipper to the clothes with a bandage or Mayo scissors (Figure 152-4, long dashed lines). Using a small or iris scissors, cut the cloth between the individual teeth that are entrapping the skin (Figure 152-4, small dashed lines). Separate the teeth and free the entrapped skin.

This technique is less than ideal. Cutting the cloth between the teeth of the zipper may cause lacerations to the entrapped skin. It is very painful for the patient when the skin is cut. Exercise great caution when cutting the zipper. Given this risk, some prefer cutting the median bar of the fastener mechanism as described above. It is worth the additional time to locate and borrow a heavy-duty wire cutter from the Maintenance Department to cut the median bar.

Cutting the Zipper Teeth

Cutting the median bar requires the proper equipment and significant strength. Skin trapped between the teeth of the zipper can be released by cutting across the zipper teeth. Cut across the closed zipper teeth using a heavy duty scissors or wire cutter. Pull both halves of the zipper apart to release the entrapped skin. This method is faster and easier than cutting the median bar if the skin is trapped only in the zipper teeth.12

If an appropriate wire cutter or bone cutter is not available, or the median bar cannot be accessed with a cutter, the previously mentioned techniques for zipper removal cannot be performed. Alternative techniques do exist but are less than ideal. Each has its own risks and contraindications. The first option is to excise the entrapped skin. This should be considered only if the excised tissue is superficial or redundant and allows for easy removal. A second alternative is to cut the median bar with a miniature hacksaw blade to divide it.10 This technique carries the risk for significant injury to the skin and soft tissues. A method using a screwdriver has been described to release skin trapped within the sliding piece.13 Insert the flat blade between the inner and outer faceplates of the slider. Twist the screwdriver clockwise and counterclockwise to widen the gap between the faceplates and release the entrapped skin. If the aforementioned alternatives are not effective to remove a zipper, consult a Urologist for consideration of more aggressive surgical interventions such as an elliptical skin excision or a circumcision.6,15

Assess the tissue for any signs of injury after the zipper has been removed from the skin. Any open wounds should be cleaned. Apply an antibiotic ointment and gauze bandage over the wound. A Urologist should be consulted for injuries to deeper penile or scrotal structures, if the entrapped tissue is not viable, if the tissue appears infected, or if the laceration is extensive.11

Patients with zipper injuries are usually discharged home from the Emergency Department. Their tetanus immune status should be checked and updated if necessary. The patient should be instructed on local wound care and signs of infection. They should return immediately to the Emergency Department if they develop redness, swelling, pus in the wound, or a fever. Otherwise, routine follow-up within 48 hours to evaluate any wounds or injured tissue is satisfactory for most patients. Although no guidelines or evidence exists, some physicians often prescribe oral antibiotics if there are any abrasions or lacerations to the skin. Nonsteroidal anti-inflammatory drugs can be used to provide analgesia.

Very few complications are associated with the removal of a zipper. Lacerations to the skin and deeper structures may occur. Superficial lacerations are commonly associated with cutting of the median bar. Deep lacerations are due to improper positioning of the wire cutter and can be prevented. Superficial lacerations will heal and require no special care. Large superficial lacerations and deep lacerations will require suturing. Hemorrhage from any laceration can be controlled with the application of manual pressure. Local infections may occur from zipper abrasions, abrasions and lacerations from removal of the zipper, or due to nonviable and crushed skin.

Zipper injuries may occur when opening or closing a zipper. The foreskin, skin of the penis, and the scrotum are the structures most commonly entrapped and injured by zippers. Injuries are most common in uncircumcised young boys, but can occur in adults with some cognitive or physical impairment. After assessing the degree of injury and the type of entrapment, the zipper should be disengaged from the entrapped tissue. Zipper removal is quick, simple, and very satisfying to the patient.