Introduction: Single-stage surgery for resection and reconstruction of bony calvarial lesions has traditionally mandated the added risk of harvesting bone from the adjacent calvarium or appendicular skeleton and/or the intraoperative molding of exogenous materials. This adds additional time and complexity to a case which can also lead to poor cosmesis. Herein we describe our experience utilizing pre-fabricated, custom titanium implants for the resection and reconstruction of such defects in a single-stage.
Methods: Image processing software is used to segment and reconstruct a 3-D cranial model from a pre-operative fine-cut CT scan. The desired margins of resection are then outlined on this model. This outline is used to remove the extent of planned resection from the 3-D model which is then used to fabricate a custom cutting guide. Virtual mirroring of the 3-D model is now used to design a custom implant which will precisely fit the anticipated defect. The cutting guide and implant are then used to resect and reconstruct the lesion in a single procedure.
Results: Three cases have been performed in the manner above for pathologies to include fibrous dysplasia, hemangioma, and an osteoid osteoma with an average patient age of 30.0 years and size ranging from 21.6 x 15.0 x 22.1 mm to 42.3 x 16.0 x 37.1 mm. The average operative time was 92.6 minutes with an average estimated blood loss of 83.3 cc. No complications were noted with good cosmetic outcomes in all cases thus far.
Conclusions: The single stage resection and reconstruction of calvarial lesions utilizing custom-manufactured titanium implants is feasible and safe. More importantly, this technique represents a step towards the use of intraoperative imaging after the removal of a bony lesion with the use of additive manufacturing (3-D printing) to fashion a custom prosthesis that can then be implanted into the patient in a single procedure.
Patient Care: This technique improves patient care by presenting a rapid means of producing a custom prosthesis that can be implanted after the resection of calvarial osseous lesions in a single operation (implant production time after obtaining required imaging is approximately 24-72 hours). Similar techniques to our knowledge typically require 3-6 weeks in order to produce an implant of identical quality by which time the lesion requiring intervention could have changed in size or character. It also acts as a link to the use of intraoperative CT to produce custom implants in an even faster manner to place if the extent or amount of resection needed for a bony lesion is unknown pre-operatively.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Identify current materials and methods used in the reconstruction of cranial defects and the benefits and shortcomings of each. 2) Understand the technique and process by which pre-fabricated, additive manufactured prosthetics are constructed. 3) Understand the operative technique for resecting and reconstructing calvarial osseous lesions with these prosthetics. 4) Understand the future directions and implications for treatment this modality can impart on the reconstruction of post-traumatic/surgical calvarial defects