Safety and Effectiveness of TETRANITE Bone Adhesive for Cranial Flap Fixation Compared to Traditional Metal Hardware

Inclusion Criteria: * Subject, and/or subject's family are able and willing to provide informed consent and HIPAA authorization prior to any study related procedures. * Subjects can be any gender, but be between (and including) 18 and 80 years of age * Subject is scheduled for a cranial procedure that requires the creation of a bone flap or replacement of a bone flap (i.e., cranioplasty) * Subject is scheduled for a cranial procedure in the supratentorial location. * Subject is able and willing to meet all study requirements, including attending all post-index procedure assessment visits and radiological tests. * Pre-operative CT scan for craniotomy patients must be less than or equal to 0.625 mm slice thickness and pixel spacing. It shall include the skull in native condition near the planned flap site DICOM export must be thin sliced reconstruction in the bone window. Intra-Operative Inclusion Criteria: • Width of craniotomy kerf line \< 3mm for more than 75% of the bone flap border. Exclusion Criteria: * Subject has undergone a previous, open intracranial neurosurgical procedure in the same anatomical location. (Note: stereotactic biopsy is not exclusionary). * Subject requires a craniectomy (the bone flap is not replaced during the current surgery). * Subject has had radiation treatment to the surgical site within the past year, or standard fractionated radiation therapy was planned within 2 weeks post index-procedure. (Note: stereotactic radiosurgery prior to the planned index procedure was not an exclusion criterion.) * Subject requires a procedure involving a translabyrinthine, transsphenoidal, transoral approach, or any procedure that penetrates the air sinus or mastoid air cells. Note: Superficial penetration of mastoid air cells is not an exclusion if cells were appropriately sealed (e.g., bone wax). * Subject has clinically significant hydrocephalus or clinical evidence of altered CSF dynamics. Subject has undergone chemotherapy treatment, excluding hormonal therapy, within three weeks prior to the planned index procedure, or use of intracavitary chemotherapy wafer (BCNU) was planned, or chemotherapy treatment was planned within two weeks after the index procedure was performed. * Standard use of peri-operative steroids (i.e., corticosteroids) is permitted. Chronic steroid use (defined as daily use of corticosteroids for ≥ 8 weeks) for the purposes of reducing the side effects of chemotherapy and/or radiation therapy for cancer is not exclusionary unless the patient is deemed by the investigator to be suffering from steroid toxicity (i.e., Cushing's syndrome) manifested by symptoms and signs such as thin skin, striae, easy bruising, muscle atrophy, upper body obesity, severe fatigue, etc. Use of corticosteroids on a chronic basis (as defined previously) for purposes other than decreasing the symptoms of systemic chemotherapy is exclusionary unless those steroids were discontinued 4 weeks prior to the planned index procedure. * Subject has a condition with anticipated survival shorter than one year. * Subject receives warfarin, heparin, other anticoagulant agents on a daily basis and pre-surgical, standard of care drug wash-out did not occur. * Subject is pregnant, breast-feeding, or intended to become pregnant during the course of the study. * Current infection (either superficial or deep) at the planned operative site * Sepsis diagnosed within one week before the planned index procedure