Metal Bridges - A New Technique of Turtle Shell Repair Joanne Richards, DYM 292 Cleveland Hill Road, Roseburg, OR 97470

A bstract: Traditionally turtle shell fractures have been stabilized with fiberglass patches, wires, or orthopedic plates and screws. However, some complex fractures are difficult to stabilize with these methods. An alternate method of shell repair uses metal strips applied as external ficators to bridge frature sites. Once epoxied to the shell, these bridges can stabilize fractures of the carapace, bridge and plastron. Metal bridges are noninvasive, simple to apply and allow continued observation and treatment of the injured area. Downloaded from http://meridian.allenpress.com/jhms/article-pdf/11/4/31/2207053/1529-9651_11_4_31.pdf by guest on 24 September 2021

Key Words: western pond turtles, Clemmys marmorata, turtle shell repair, fracture.

In southwestern Oregon, western pond turtles, Clemmys sive than drilling to accommodate wires or screws so the use marmorata, typically weigh 700 g or less and have a carapace of anesthetics may be reduced. This may be especially impor­ length of 20 cm or less. When moving between water and tant for severely traumatized individuals that are not good land for spring nesting or autumn hibernation, these semi- candidates for anesthesia and lengthy surgical procedures. aquatic turtles are vulnerable to injury from vehicles. Injuries Metal bridges allow wound areas to be examined and treat­ to these small turtles often include multiple fractures of the ed. Areas can be left partially’ open for drainage or carapace, bridge and plastron. periodically be reopened. The epoxied bridges can be Stabilizing multiple shell fragments with fiberglass patches, removed with the dull end of a metal scalpel handle without wires or orthopedic plates and screws is often difficult. damaging the shell. This is done by levering the scalpel han­ Placing fiberglass patches across multiple fractures is a time- dle under the bridge and gently applying pressure. The bridge consuming process of shingling patches across the length of will loosen easily without removing the dermal elements the fracture line and allowing the material to dry between associated with the epoxy. After the wound area is lavaged applications (Frye, 1991). This procedure may take days to and debrided, the metal bridge can be reapplied. Traditional complete, which may be impractical in a severely traumatized tenets of wound therapy can be followed and the healing pro­ patient. Aligning shell fractures with wire or orthopedic plates moted with flushing, debridement and the placement of and screws may also be difficult and requires drilling into the drains. The flexibility of this method to conform to the indi­ shell. Drilling into fragile shell pieces may cause additional vidual injury and shell architecture make it an exceptionally fragmentation. Also, when the wires and screws are removed helpful technique. the resultant holes require additional healing time. Wild turtles may present long after the shell fracture MATERIALS AND METHODS occurs, with debris and myiasis contaminating the wounds. Such shell injuries would benefit from open wound manage­ Metal bridges used on western pond turtles include 20 g ment (Barten 1996, McArthur, 1996, Bonner, 2000). Open anodized aluminum, 16 g brass, and 26 g stainless steel. wound Management of complex fractures without shell stabi­ Aluminum and brass supplies are available at many model lization is impractical. Stabilization is required to prevent train stores. Stainless steel sheets and other metals are avail­ additional damage to the fragments, contamination by able from furnace and air conditioner ductwork bacterial and parasitic organisms, and pain associated with manufacturers. Metal sheets vary in thickness ffoml6 to 30 g. fragment instability. It is also required to promote healthy These materials can be cut into a variety of widths and lengths granulation tissue and callus formation between shell frag­ to form the metal bridges. Typically, the metal bridge is ments. Finally, normal chelonian ambulation and respiratory approximately 0.5 cm wide and 3.0 cm long to span a frac­ function require firm shell architecture for muscles to function ture. The material is bent to conform to the fracture site and properly. Therefore, a method that allows both stabilization of shell shape using pliers and Vise Grips™ (American Tool the shell fragments and continued wound treatment would be Company, Inc., DeWitt, NE 68341) (Figure 1). Metal bridges beneficial. can be either cold or steam sterilized prior to the procedure. Multiple strips of metal can be effectively used to stabilize Devcon 5 Minute Epoxy ™ (ITW Performance Polymers complex shell fractures. Applying several metal strips from Consumer Division, Riviera Beach, FL) is used to attach the the stable portion of the shell to the injured portion immobi­ metal bridge to the shell. It is readily available from hardware lizes the fracture. Each metal strip is epoxied at one end to the and variety stores. It is less exothermic than many acrylics uninjured shell and at the other end to the shell fragment. that potentially may burn shells. (Allbritten, 1999) It has Using metal bridges, multiple shell fractures can be quickly 1500 lbs of holding power per square inch and it is waterproof aligned and rigidly stabilized. Affixing metal bridges is less (Frye, 1991, Barten 1996). time consuming than using fiberglass patches and less inva­

Volume 11, No. 4,2001 Journal of Herpetological Medicine and Surgery 31 For fractures of the carapace, metal bridges may have high archways for ease of handling and injury examination (Figure 2A). Metal bridges spanning fractures of the bridge and plas­ tron must have low archways to allow the animals to ambulate without interference from the metal bridge (Figure 2B). These conforming metal bridges must be carefully applied to prevent the epoxy from oozing across the underside of the metal archway and entering the wound site. At either end of the bridge, the foot accepts the epoxy and helps limit its potential spread. The epoxy should be tacky and must be applied sparingly to the bridge feet to prevent it from entering the fracture site. Once placed on the shell, the metal bridge and shell pieces must be held stationary while the epoxy hardens. In order to

reduce procedure time, it is helpful to have an assistant pre­ Downloaded from http://meridian.allenpress.com/jhms/article-pdf/11/4/31/2207053/1529-9651_11_4_31.pdf by guest on 24 September 2021 pare a new batch of epoxy for the next bridge while the first Figure 1. Materials used to prepare metal bridges include (from bridge is being held in place. Then it is possible to efficiently the top): Devcon 5 Minute Epoxy™, metal shears, pliers and and sequentially place bridges across a long fracture line as Vise Grips™, brass, aluminum and stainless steel of various the bandages holding the fragments in place are removed. gauges. Mixing cups and toothpicks for applying the epoxy are also suggested. After the metal bridge is affixed across the fracture site, addi­ tional epoxy should be applied over the edges of the footings to further secure the metal bridge to the shell. A compromise must be made between the urgency to stabi­ lize the traumatized patient’s physiology and its shell architecture. In some cases, bridges are not applied until the underlying granulation tissue appears healthy. For other cases, bridges are placed soon after physiological stabilization has been achieved to prevent additional fragmentation and contamination of the wound area (Figures 3A, 3B, 3C). However, fractures impacting vital areas, Such as the spinal column, may require immediate application of the metal bridges to stabilize both the animal’s physiology and architec­ ture (Figures 4A and 4B). For these reasons, the timing of surgery must be left to the assessment of the clinician. Traditional wound therapy may be practiced after metal bridges are applied. Bandage changes, lavage and debride­ ment can be utilized to encourage granulation tissue (Figure Figure 2a. A conforming metal bridge with low archway stabi­ 3D). Various ointments and bandage materials, such as sterile lizes the turtle’s bridge fracture, while the carapace fractures are gauze pads, Telfa™ pads (The Kendall Co., Mansfield, MA) stabilized by metal bridges with high archways. and Tegaderm™ (Transparent IV Dressings, 3M Medical- Surgical Division, St. Paul, MN) may be applied to promote healing. For aquatic turtles, bandages may be given a water­ proof barrier by gluing the edges of Tegaderm™ dressings with a cyanoacrylate ester, such as Quick Tite Superglue (Loctite Corp., Rocky Hill, CT) (Campbell, 1996). However, western pond turtles do not have to be in water at all times so limited daily access to water and frequent bandage changes can suffice. To further encourage healing, environmental temperatures of approximately 30°C (86°F), full-spectrum lights and good nutrition should be provided. Using this method, six shell-frac­ tured western pond turtles have been stabilized with metal bridges, over-wintered and released the following summer. Metal bridges allow the repair of turtle shell fractures with an ease that is not possible with fiberglass patches, wires or orthopedic plates and screws. In addition to stabilizing com­ plex fractures, metal bridges allow the practice of traditional wound therapy. As a non-invasive external fixation technique, metal bridges may improve the outcome for turtles with shell fractures. Figure 2b. The carapace’s surface appears normal after removal of metal bridges. Time elapsed between application and removal was ten months and two days.

32 Journal of Herpetological Medicine and Surgery Volume 11, No. 4,2001 Downloaded from http://meridian.allenpress.com/jhms/article-pdf/11/4/31/2207053/1529-9651_11_4_31.pdf by guest on 24 September 2021 Figure 3A. The presenting injury after lavage but prior to appli­ Figure 3B. The same turtle three weeks after the metal bridges cation of metal bridges. Arrows indicate where the left bridge is were applied. The bridges are 16 g brass and 20 g anodized alu­ separated from the carapace. The turtle’s bridge is fractured and minum. The two thinner bridges in the photograph are unstable dorsally, cranially and caudally. In addition, a portion of aluminum. 1% silver sulfadiazine cream was applied to delineate the carapace is absent. the extensive fracture area.

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Figure 3C. A view of this turtle’s bridge taken three weeks after Figure 3D. Ten weeks after presentation and extensive wound the metal bridges were placed. 1% silver sulfadiazine cream was management, healthy granulation tissue is repairing the defect in applied to delineate the fracture area. the carapace. The bandage material includes a sterile Telfa™ pad covered by Tegaderm™ dressings.

Figure 4A. This turtle was presented two hours after the injury Figure 4B. The cleaned and decompressed injury with metal with antibiotic ointment applied to the wound area. The fracture bridges applied to the carapace. A 1 % silver sulfadiazine cream was compressing the spinal cord. was applied to better delineate the fractured areas of the shell. The bridges were applied 10/20/00. As of 8/5/01, this animal’s hind limb paresis is still resolving.

Volume 11, No. 4,2001 Journal of Herpetological Medicine and Surgery 33 REFERENCES Campbell TW. 1996. Semi-occlusive bandaging in aquatic turtles. Proc NAVC, 823. Allbritten ML. Personal communication. 1999. Oregon Frye FL. 1991. Biomedical and Surgical Aspects of Captive Department of Fish and Wildlife, 4192 N Umpqua Hwy, Reptilian Husbandry. Krieger Publishing Co., Malabar, Roseburg, OR 97470. FL:434-452. Barten SL. 1996. Shell damage. In Mader, DR (ed): Reptile McArthur S. 1996. Surgical techniques and shell repairs. In Medicine and Surgery. WB Saunders Co, Philadelphia, Veterinary Management of Tortoises and Turtles. Blackwell PA:413-416. Science Ltd., Oxford, England: 105-109. Bonner BB. 2000. Chelonian therapeutics. In Veterinary Clinics of North America: Exotic Animal Practice. W.B.Saunders Co, Philadelphia, PA:3(l):257-289. Downloaded from http://meridian.allenpress.com/jhms/article-pdf/11/4/31/2207053/1529-9651_11_4_31.pdf by guest on 24 September 2021

Journal of Herpetological Medicine and Surgery Volume 11, No. 4,2001