PEEK has good compatibility with the human body and is used as an artificial bone material, successfully replacing traditional titanium. In the field of cranial repair, PEEK has become an ideal material for cranial repair

 

3D Printed Medical Devices: PEEK Cranial Repair Plates

 

Hazards of skull defects

 

The skull, as an important skeletal structure in the human body, plays a crucial role in protecting the brain and maintaining the stability of the intracranial environment. Once there is a skull defect, the impact is multi-faceted and extremely serious.​

 

Visually, a skull defect can cause significant changes in the patient's head shape, leading to conditions such as sunken skull or abnormal head circumference, which can directly affect the patient's appearance, causing feelings of inferiority and depression, and thereby impacting social and career development.​

 

On a health level, a skull defect is not simply an aesthetic issue. When there is a large area of skull defect, the intracranial pressure loses balance and abnormally increases. At this point, patients often suffer from symptoms such as headaches, nausea, vomiting, blurred vision, and difficulty walking, and the brain is also further damaged. For example, in daily activities, simple actions like bending over or looking down can exacerbate headache and dizziness, severely affecting the patient's normal life. For some elderly patients, severe dizziness can even lead to falls, resulting in other accidental injuries.​

 

Brain tissue loses the protection of the skull, and the structures of nearby tissues also face the risk of abnormality and displacement, greatly affecting cerebral circulation. Patients are prone to symptoms of neurological damage such as inattention and memory decline. In infants and young children, if there is a skull defect, it can also hinder normal brain development and increase the risk of seizures.

 

As intracranial pressure fluctuates, a series of complications will also follow, such as hydrocephalus and cerebrospinal fluid circulation disorders. These pose a serious threat to the patient's physical health and reduce their quality of life. Therefore, skull repair is urgent, and 3D-printed PEEK skull repair plates bring new hope to patients.

 

cranial repair materials

 

Currently, titanium alloy mesh has become the mainstream material for cranial bone repair. Titanium alloy mesh has high strength and corrosion resistance, capable of withstanding certain external pressures to protect the cranial internal tissues. Moreover, it has good biocompatibility and is unlikely to cause severe immune reactions or allergic reactions. Compared to previous materials, titanium alloy mesh represents a significant advancement, dominating the field of cranial bone repair. However, titanium alloy mesh is not perfect; it has high thermal conductivity and poor thermal insulation, making patients sensitive to cold and heat in their daily lives. In winter, a cold wind can make the head feel extremely cold; in summer, exposure to sunlight can make the head feel abnormally hot. Additionally, as a metal material, titanium alloy mesh can affect patients' subsequent medical examinations, such as CT and MRI, leading to image artifacts that can interfere with doctors' diagnoses and cause significant inconvenience to patients. The emergence of polyetheretherketone (PEEK) material has brought breakthroughs to cranial bone repair. Its appearance has injected a powerful new force into the field of cranial bone repair, offering new hope for cranial bone repair.

 

What is PEEK material

 

PEEK, is the abbreviation of polyetheretherketone (Polyetheretherketone), which is a high-performance special engineering plastic, which belongs to semi-crystalline linear thermoplastic polymers. From the point of view of molecular structure, it is composed of amorphous and crystalline phases, the molecular chain contains benzene rings, ether bonds and carbonyl groups, and the p-phenylene group is connected by an oxygen bridge (ether and ketone). This special molecular structure gives PEEK many excellent properties.

 

In terms of high temperature resistance, PEEK performs very well, its melting point is as high as 343 °C, the glass transition temperature is 143 °C, the long-term use temperature can reach 260 °C, the instantaneous use temperature can reach 300 °C, almost no decomposition in a short period of 400 °C, its high temperature resistance is much higher than that of ordinary plastics and engineering plastics, even compared with polyimide (PI), polyphenylene sulfide (PPS) and other high-temperature resistant plastics, the upper limit of the use temperature is nearly 50 °C, and it also has outstanding heat aging resistance, in After holding at 250°C for 3000h, the flexural strength is almost unchanged.

 

In terms of mechanical properties, PEEK has some of the best mechanical strength characteristics among engineering plastics, with tensile strength above 90MPa, high elastic modulus, high hardness, and strong impact and creep resistance. It can maintain high strength even at high temperatures, such as 24MPa at 200°C and 12 - 13MPa at 250°C, making it particularly suitable for components that work continuously at high temperatures. At the same time, PEEK's toughness, impact resistance, creep resistance, fatigue resistance and other properties are also excellent, and the excellent fatigue resistance to alternating stress is outstanding among all plastics, even comparable to alloy materials, and the comprehensive mechanical properties far exceed those of other thermoplastic resins.

 

PEEK is also chemically stable, has excellent resistance to various organic solvents, oils, weak acids and bases, is almost insoluble in other acids, bases and organic solvents except for concentrated sulfuric acid, has similar corrosion resistance to nickel steel, and can maintain strength over a wide range of temperatures and concentrations. In addition, it has excellent irradiation resistance, under high doses of ionizing radiation, the parts can also work normally, can withstand the irradiation dose of 1100 MRAD (megarad) without loss of performance, exceeds the general radiation resistance material polystyrene, and can resist gamma rays and electron beam radiation, which are commonly used in the sterilization of medical devices.

 

It is because of these superior properties that PEEK is widely used in many fields. In the aerospace field, it is used to manufacture engine parts, insulating materials, etc. for aircraft; In the automotive industry, it can be used to manufacture high-performance automotive parts and battery brackets for electric vehicles; In the medical field, because of its good compatibility with the human body, it is used as an artificial bone material, successfully replacing the traditional titanium metal. In the field of cranial repair, PEEK has shown great advantages and has become an ideal material for cranial repair.

 

3D printing how to create PEEK cranial implant plates

 

When it was decided to use PEEK for skull restoration, 3D printing technology kicked in. First, the doctor performs a CT scan of the patient's head, which is a crucial step that takes a high-precision "map" of the patient's skull, which extracts accurate 3D data. These data contain detailed information about the location of the skull defect, such as the shape, size, and location of the defect, as well as the structure of the surrounding skull.

 

Next, a professional technician will use computer software to perform a 3D reconstruction based on the CT data of the head. It's like remodeling a patient's skull in a virtual world, turning CT data into intuitive, three-dimensional images. During this process, the technician can observe the condition of the skull from all angles and make fine adjustments to the reconstructed model to ensure the accuracy of the model.

 

After the 3D reconstruction is completed, it is time to enter the 3D printing process. The 3D printing technology is like a magical craftsman, according to the shape of the 3D reconstruction model, the PEEK material is stacked layer by layer, and gradually shaped into a repair plate that fits perfectly to the patient's skull defect. During the printing process, the thickness and position of each layer of PEEK material are precisely controlled to ensure the accuracy and quality of the repair board. The PEEK skull repair plate made by 3D printing technology can not only highly restore the original shape of the skull, but also have a high degree of compatibility with the skull defect site, which is customized for patients and can provide accurate and effective protection for the brain.

 

3D printing PEEK cranial implant advantages

 

High fit

 

With its unique digital manufacturing method, 3D printing technology can accurately convert the 3D data of the patient's skull defect into a physical model. Through meticulous analysis and 3D reconstruction of the CT data of the head, technicians can accurately design the skull repair plate in a virtual environment to ensure that it perfectly matches the shape, size, curvature, etc. of the patient's skull defect.

 

This personalized approach allows the PEEK skull repair plate to highly restore the original shape of the skull, achieve embedded repair, and fit perfectly with the bone window. During the operation, the doctor can easily place the repair plate accurately at the defect site, and the connection between the repair plate and the surrounding skull is smooth and natural, which improves the success rate and efficiency of the operation, reduces the risk of postoperative complications, and provides a strong guarantee for the patient's recovery, which is comfortable and safe.

 

Good biocompatibility

 

PEEK material itself is non-toxic, corrosion-resistant, non-conductive, non-hydrolyzed, and has excellent stability. When it is implanted in the human body, it does not arouse the alertness of the body's immune system and produces almost no immune response or rejection. Moreover, PEEK material has a strong affinity with human tissues, can be closely integrated with the surrounding skull tissues, and gradually integrates into the physiological environment of the human body, just like integrating with the autologous skull, so that the patient can hardly feel the presence of foreign bodies. This is of great significance for improving the quality of life of patients, reducing psychological burden, and enabling patients to return to normal life faster.

 

Does not affect medical imaging

 

In modern medical diagnosis, imaging examinations such as X-rays, CT and MRI are important means to understand the patient's physical condition and evaluate the effect of treatment. PEEK material has good X-ray penetration, is transparent, and is inherently non-magnetic. This means that after the implantation of the PEEK skull repair plate, X-rays, CT and MRI examinations will not interfere with the imaging results, and the doctor will be able to clearly observe the patient's skull and accurately determine the condition. For example, during CT scanning, there are no artifacts in the images, and doctors can clearly see the details of brain tissue, which can detect possible problems in time and provide accurate basis for subsequent treatment. This advantage provides great convenience for postoperative follow-up and treatment of patients, allowing doctors to better track the patient's recovery progress.

 

Excellent mechanical properties

 

The strength and elasticity of the PEEK skull repair plate are very close to that of human cortical bone, which allows it to effectively disperse the impact force like a natural skull when subjected to external impacts, protecting brain tissue from injury. When the head is impacted, the repair plate can quickly and evenly distribute the impact force to the entire skull surface, avoiding local excessive force and causing damage to the brain tissue. And, in everyday life, whether it's a minor bump or normal head activity, PEEK skull repair plates remain stable and won't easily deform or be damaged. In addition, PEEK material also has excellent stability, and its performance can remain stable in harsh environments such as high temperature and radiation, and will not be degraded or changed. This means that when patients receive radiotherapy, chemotherapy and other treatments, the repair plate will not be affected, and can continue to provide reliable protection for patients and escort their health.

 

Example image