## 1 Introduction  
Orthopedic implants are the cornerstone of modern medicine, offering critical solutions to restore mobility and improve the quality of life of patients with musculoskeletal disorders. Among the materials used in these implants, Polyaryletterketone (PAEK) has emerged as the leading choice due to its remarkable combination of properties. PAEK stands out for its exceptional mechanical strength, high thermal stability, and resistance to chemical degradation, making it particularly suitable for long-term orthopedic applications [1]. Polyetheretherketone (PEEK) and Polyetherketoneketone (PEKK) belong to the PAEK family. The key advantage of PAEK is its compatibility with advanced manufacturing techniques such as 3D printing. This capability allows for the creation of highly precise, patient-specific implants with complex geometries, which are difficult to acquire using the traditional manufacturing methods [2]. PAEK implants are especially valuable in orthopedic surgery, where tailored designs can enhance the patient outcomes by ensuring a better fit and function. Unlike metallic implants, PAEK's radiolucency makes it easier for surgeons to monitor healing progress postoperatively using imaging techniques. The traditional metallic implants have been widely used in orthopedic surgery, but they come with notable limitations, including stress shielding, poor bioactivity, and compromised postoperative imaging quality. Stress shielding occurs when metallic implants, which are much stiffer than natural bone tissues, bear too much load, potentially leading to bone resorption and the weakening of the surrounding tissue. Additionally, the non-radiolucent nature of metals often interferes with the imaging techniques, making it difficult to monitor healing post-surgery. PEEK and PEKK offer a promising alternative to these metallic implants by addressing many of the shortcomings of metallic implants. Unlike metals, PEEK and PEKK are radiolucent, allowing for clear imaging, and their mechanical properties more closely resemble those of natural bone, reducing the risk of stress shielding. However, with these advantages, they present their own set of challenges. Among them is their hydrophobic nature, which limits cell adhesion and impairs osseointegration, making it difficult for the implant to effectively bond with the surrounding bone tissue. To overcome this issue, other researchers have explored the incorporation of bioactive agents such as hydroxyapatite (HA) into PEEK and PEKK. HA is a calcium phosphate-based biomaterial that is widely recognized for promoting bone growth and osseointegration, and it has been successfully used in coatings for hip and knee replacement implants [3]. When HA particles are evenly distributed within the PEEK matrix, the implants can benefit from the bioactivity of HA, while maintaining the structural advantages of PEEK. This composite design allows for HA to be exposed on the implant surface, facilitating better integration with the bone and promoting faster healing [4]. In addition to the use of HA, implant design, such as the creation of porous scaffolds, is showing promise in improving PEEK's performance in orthopedic applications [5]. Porous scaffolds encourage tissue regeneration by allowing soft tissues to grow into the implant, further enhancing the integration of PAEK implants within the body. Together, these innovations are helping circumvent the limitations of the traditional PAEK implants, pushing the boundaries of what is possible in orthopedic surgery and improving patient outcomes [6]. Neck and lower back pain has significant psychological, economic, and social burdens, which can be caused by several factors, such as accidents, injuries, or spinal disorders like scoliosis, congenital deformities, and degenerative diseases, affecting over 80% of the population [7; 8; 9]. These conditions strain healthcare systems like the National Health Service, which spends GBP 26 million annually on spinal fusion surgeries aimed at improving patients' quality of life [7].