Bone wax suture is a sterile hemostatic agent made of mostly beeswax, isopropyl palmitate, a wax softening agent, and a stabilizing agent such as almond oils or sterilized salicylic acid. It is used to control bleeding of disrupted bone surfaces. The action is not biochemical, rather it acts as an impenetrable mechanical barrier (tamponade) to seal the bone.
Its resorption is minimal from the site of application. It is strongly hydrophobic and is not metabolized. It has no effect on pH of the body fluid.
Bone wax is sterile, opaque, soft, easy to shape, has a waxy odor, and apply “only hand-warm”. It is not absorbed by the body as it is biochemically inert, and has to be removed.
The first known type of bone wax was made by Sir Victor Alexander Haden Horsley in 1885, using seven parts of beeswax, one part of almond oil and one percent of salicylic acid. The first use in surgery was first reported in 1892, when Rushton Parker stopped bleeding from the lateral sinus using the suture.
The suture is applied after surgery and removed during the change of bandage. Bone wax is supplied in easy-to-open foil package in the form of sterile sticks or plates. It is classified as Class 2 medical device by the US Food and Drug Administration (FDA).
Popular brands of the suture include Haemowax (Universal Sutures), Ethicon, B Braun, Aesculap, Covidien, Surgical Specialties, and CP Medical. It is usually supplied in a box of 12 pieces (containing 2.5 gram bone wax per pouch).
Advantages of the Bone Wax
Bone wax has advantages over other options used for bone hemostasis, such as:
Absorbable hemostatic agents like collagen and oxidized cellulose
Oxidized cellulose is an inappropriate-knitted fabric, that does not adhere to the bone. This presents an issue with sealing irregular surfaces and pores of defective bone. Collagen, on the other hand, when used alone or in combination with fibrin and suspended in delivery vehicles, has been used proposed for use as a bone hemostatic agent. But issues with the cohesiveness, biocompatibility, and storage stability prevents its clinical application.
Electrocautery, when applied, thermally sears oozing blood vessels and closes them, but it may cause problems such as inducing severe thermal damage to tissues, that could delay osteogenesis and allow soft tissue ingrowth interfering with the union of normal bone. It is also time-consuming.
On the other hand, bone wax offers more advantages, which include the malleability and smooth consistency of the material of the bone wax. Hence, it can be smeared across the cut surface to plug the holes in the bone, to stop the bleeding.
Also, the use of bone wax is necessary in situations like bone bleeding or irregularly shaped area (conchal bows), where it is difficult to apply pressure bandages. Pressure bandages acts like mechanical occlusion using petrolatum and gauze to aid hemostasis after cutaneous surgery.
Bone wax has a longer shelf life (5 years), and is a less expensive option to other physical hemostatic agents such as gelatin, chitin, microfibrillar collagen, oxidized cellulose, microporous polysaccharide spheres, hydrophilic polymers with potassium salts.
An additional advantage is that bone wax is not absorbed and does not adhere to wound edges, which may lead to repeat trauma during removal. It is therefore painless and easy to remove.
Bone wax helps the granulation tissue to grow well as the beeswax has healing and emollient properties, and also the moist occlusive environment created by the bone wax.
In cases where the cutaneous tumors extend into the calvarium, bone wax can prevent air emboli from entering non-collapsible emissary veins.
Major Indications of Bone wax
When the cancellous and cortical bones have fractures, it can damage the vascular tissues, causing osseous hemorrhage. This hemorrhage can be difficult to control naturally, hence the need for agents to provide bone hemostasis. Bleeding can lead to tissue necrosis, and blood loss, which may be fatal.
Bone wax control bleeding from bone surfaces during surgical procedures such as:
Dental, oral and jaw surgery
Neurosurgery (trepanation)
Thoracic surgery (sternum and ribs)
Orthopedics and traumatology
It can also be used to modify surgical tools for blood control purposes. For example, in percutaneous endoscopic cervical discectomy, where it smeared onto the endoscopic burr to control bleeding without interfering with bone healing.
Also, after arthroscopic repair of the anterior cruciate ligament, it can be used to prevent the leakage of blood through the lumen of a cannulated screw.
In a study using 400 thoracic surgical patients undergoing isolated coronary bypass surgery, the use of bone wax after median sternotomy did not effectively control the loss of blood. However, in the reports of total knee arthroplasty, where bone wax was effective in reducing blood loss and maintaining higher hemoglobin level.
Since the bone wax is inert, it may cause complications such as foreign body reactions, reduces the chances of bone healing and also promotes infection of the wound. Other complications include granuloma growth, thrombosis, and nerve compression.
It can also cause inflammatory reactions such as redness, swelling, heat, and pain.
A study using a rabbit model and Staphylococcus aureus also showed that bone wax, as a foreign body, can reduce the ability of the cancellous bone to clear bacteria.
Precaution
The suture is used immediately after it is used from the package.
Bone wax should be softened to a desired consistency before it is applied by molding with the fingers or immersing the unopened foil packet in a warm sterile solution
Do not use excessive heat, as it may inhibit osteogenesis and act as a physical barrier to the reparative process.
The best storage temperature is 10°C – 35°C, away from moisture and direct heat.
Contraindications
Not to be used when a rapid osseous regeneration and bone fusion is needed, as it may act as an artificial barrier and prevent bone regeneration (osteogenesis)
Because of the risk of infection, do not use bone wax in contaminated zones. It is advised to clean bone wax in iodine after manual manipulation.
Avoid use in patients with known allergies or sensitivities to beeswax, paraffin wax and isopropyl palmitate.
