Cranial Defect with Custom Implant in a 62-Year-Old Patient | Dr. Mohsen Soltani Gard faramarzi

The patient is a 62-year-old female who sustained traumatic loss of portions of the left temporal, frontal, and parietal cranial bones following a severe head injury. As a result of this extensive cranial bone defect, she was referred for the design and manufacturing of a patient-specific cranial prosthesis.

Physician profile

Dr. Mohsen Soltani Gard faramarzi

Neurosurgeon
Fellowship-Trained Spine Surgeon

Three-Dimensional Model of the Patient’s Skull

Pre-operative Planning

To ensure accurate cranial prosthesis design and achieve maximum anatomical conformity, the preoperative planning process was performed based on the patient’s computed tomography (CT) imaging data. The acquired images were imported into specialized biomedical engineering software, where a three-dimensional reconstruction of the skull was generated.
For reconstruction of the osseous defect, a mirroring technique based on the healthy side of the skull was utilized. Key anatomical landmarks, including the nasion, supraorbital ridge, and zygomatic arch, were selected as reference points. These landmarks played a crucial role in defining the reference planes and accurately reconstructing the natural cranial contours, enabling the restoration of appropriate cranial symmetry.

Determination of the Patient’s Symmetry Plane Based on Anatomical Landmarks

Following reconstruction of the defect geometry, a patient-specific implant was designed while considering both biomechanical and biological requirements. A uniform implant thickness of approximately 1.5 mm was selected to provide sufficient mechanical strength while minimizing unnecessary weight.
Appropriate fixation sites were incorporated in the form of flanges to ensure even force distribution along the implant margins and to achieve optimal primary stability. The design included nine fixation flanges, each containing two screw holes compatible with 1.6-mm titanium screws.
To reduce pressure on the underlying tissues and facilitate fluid exchange, perforations were incorporated into the implant surface. In addition, a porous mesh-like structure was implemented to decrease implant weight and improve adaptation to the surrounding tissues. This feature may also contribute to enhanced tissue integration and reduced postoperative complications.
To further improve surface characteristics and promote osseointegration with adjacent tissues, both the internal and external surfaces of the implant underwent a sandblasting process, creating a controlled surface roughness. Finally, a trial implant was manufactured for preoperative evaluation, allowing assessment of surgical dissection adequacy and preliminary implant fit during the procedure. This step plays an important role in reducing intraoperative errors and improving the accuracy of final implant placement.

Implant Design Based on the Patient’s Defect Geometry While Preserving Facial Symmetry

Surgical Treatment

Given the extent of the cranial defect and according to the predetermined treatment plan, the surgery was performed under general anesthesia. Based on the surgeon’s decision, surgical access was obtained through a coronal approach. Following elevation of the soft tissue flap, the bony defect was fully exposed.
A trial implant was then used to assess the adequacy of dissection and evaluate preliminary fitting. After confirming appropriate positioning and sufficient surgical space, the definitive implant was placed into the defect site. The implant was carefully assessed for marginal adaptation and conformity with the surrounding anatomical structures. Once an optimal fit was verified, the implant was secured using titanium screws to achieve primary stability.
Throughout the procedure, meticulous attention was paid to avoiding excessive pressure on the underlying tissues and preserving the safety of vital anatomical structures. Following thorough irrigation of the surgical field, the soft tissue flap was repositioned, and the surgical layers were closed anatomically in a stepwise fashion. The patient was subsequently transferred to the recovery unit in stable condition.