Orthopedic fixation is highly dependent on orthopedic screws, as they assist the bone in healing by holding the fractured bones together and reducing stress on orthopedic implants.1 There are currently a variety of orthopedic screws available, ranging from cortical screws to cannulated, from metallic materials to biodegradable. Each orthopedic screw has its pros and cons, but it comes down to the fracture, location, and end result you want.
Cortical bone, the thick outer surfaces of long bones enclosing the bone cavity, are where cortical screws are used. These screws have very fine threads along their shaft, designed to anchor the cortical bone.2
Cancellous screws, which are longer than cortical screws, are characterized by coarser threads and deep cuts.2 Cancellous screws are used to repair fractures in cancellous bones found in the neck portion of a long bone.1 These screws usually cut through their path when being inserted due to their threads.1
Stainless steel, a very common type of orthopedic screw, can range from 1.5 to 6.5mm depending on the injury and bone type. Titanium is another very common option, often used in treating mandibular fractures.2 These screws can be used in cortical bone or cancellous bone.
While the rate of infection is much lower in titanium screws compared to stainless steel screws, long-term exposure of these implants greatly increases the risk of complications such as foreign body reactions and inflammation due to the release of ions or particles due to wear/degradation.3 This leads to the necessity of an additional surgery to remove the implant after sufficient tissue healing.3
As many facilities are putting an emphasis on cost savings, any additional surgery to remove an implant would understandably increase the costs to both the patient and the health care system. Because of this, there has been a growing interest in biodegradable materials.
With the concept that the implant maintains structural integrity during the bone healing process and naturally degrades and is removed by the body, bioabsorbable screws require no additional surgery.3
The SmartNail® Implant is a bioresorbable bone fixation nail for use in the fixation of fracture fragments following trauma or osteochondritis dissecans lesions (OCL). The self-reinforced manufacturing process preserves high initial mechanical strength and stiffness of the implants. With adequate immobilization, the SmartNail® ensures accurate alignment of small bone fractures and apex fragments, osteochondral fragments, and non-weight bearing cancellous bone fragments following arthroscopic or open surgery. The flat, round head provides increased compression of bone fragments, while fine barbs offer even better stabilization.
To learn more about the SmartNail® Implant, click here.
1https://www.madisonortho.com/blog/a-brief-guide-to-the-major-types-of-orthopedic-screws
2https://healthnewscenter.com/en/post/17-orthopedic-screws
3https://www.sciencedirect.com/topics/engineering/fracture-repair