The goal of this clinical trial is to determine the efficacy and safety of customized skull implants made of polyetheretheretherketone by three-dimensional printing in patients undergoing cranioplasty. The main question it aims to answer is:

• Are customized skull implants made of polyetheretheretherketone using 3D printing effective and safe in patients undergoing cranioplasty?

Participants will:

• The patient will be submitted to cranioplasty.
• The patient will answer the neurological scales at each visit.
• Keep a diary of their symptoms and concomitant medications
• The study will be divided into 5 visits to the center, the surgical intervention and 3 telephone calls where patients will be followed up.

The aim of this study is to evaluate the efficacy and safety of personalized skull implants made of polyetheretheretherketone (PEEK) using three-dimensional printing in patients undergoing cranioplasty. This is a phase II clinical trial, with a single group of 30 patients who have suffered cranial bone loss. Specific objectives include analyzing the incidence of complications (infections, fractures, implant exposure), assessing functional recovery using recognized scales such as the Glasgow and Barthel scales, and measuring patient and surgeon aesthetic satisfaction over 12 months.

The design includes multiple follow-up visits, from surgery to one year after, where neurological, functional and cosmetic assessments will be performed.

The selection and exclusion criteria ensure the suitability of the participants, while the variables monitored allow a comprehensive analysis of the results, from cognitive functionality to surgical complications. This study seeks to provide scientific evidence to support the implementation of this technology in patients with cranial defects, improving both quality of life and post-surgical aesthetic and functional outcomes.

-Main inclusion criteria: Being older than 18 years, of both sexes. Loss of cranial bone segment greater than 1 cm². Glasgow Coma Scale (GCS) score equal or greater than 9. Satisfactory pre-surgical evaluation. Signed informed consent.

-Main exclusion criteria: Local infection at the craniotomy site or active systemic infection. Presence of previous surgical instruments at the cranioplasty site. Need to use two or more implants for reconstruction. History of coagulopathies, uncontrolled diabetes mellitus or body mass index (BMI) greater than 35.

Pregnant or lactating women.

-Main variables: Efficacy and safety: frequency of complications such as infections, fractures and implant exposure.

Cognitive functionality: Assessed by the Mini-Mental State Examination (MMSE). Functional independence: Measured with the Barthel index. Degree of disability: Assessed with the Modified Rankin Scale (mRS). Cosmetic satisfaction: Patient and surgeon satisfaction. Adverse events: Incidence during the 12 months of follow-up.

Inclusion Criteria:

• Adults >18 years old.
• Both sexes.
• Who agree to participate and sign the informed consent form.
• With loss of a bone segment.
• Area of bone segment loss greater than 1 cm.
• Glasgow Coma Scale score equal to or greater than 9.
• Satisfactory preoperative evaluation

Exclusion Criteria:

• Presence of local infection at the craniotomy site or any type of systemic infection at the time of medical evaluation and systemic infection at the time of medical evaluation and during surgery.

• Presence of previous surgical instruments in the cranioplasty site.

• Need to use two or more implants for the reconstruction.

• The resulting angle between the tangential lines to the curvature of the implant and the tangent determined to the center of the implant, determined to the center of the implant, is greater than 50º.

• Patients whose cranial morphology presents difficulties for the prosthesis design.

• Presence of postoperative ossifications in the defect area.

• History of hypersensitivity to biomaterials.

• Surgery at the same site within the 6 months prior to the study surgery.

• Patients with any diagnosis that affects blood supply and bone quality.

• Patients who have received chemotherapy or radiotherapy in the surgical region that ended within 6 months prior to the planned surgery or are scheduled for the next 12 weeks.

• Diagnosis of malignant cranial tumor.

• History of any status epilepticus.

• Known history of hemophilia or other clinically significant coagulopathy.

• Patients with uncontrolled diabetes according to, ADA criteria:

  o fasting glucose ≥ 200 mg/dL, HbA1C ≥ 8.5% in the last 3 months.

• Patients with a body mass index (BMI) ≥ 35 kg/m

• History of steroid drugs at least 3 months before surgery.

• Women breastfeeding or pregnant.

• Inability to read and understand the participant's information.

• Prior participation in any related investigational drug or device study within 30 days.

The decision to share IPD is currently 'Undecided' because further discussions and evaluations are needed regarding the feasibility, ethical considerations, and alignment with institutional policies. Once these factors are thoroughly assessed, a final determination will be made.