Evaluation of the Fitting Accuracy of CAD/CAM-Manufactured Patient-Specific Implants for the Reconstruction of Cranial Defects—A Retrospective Study

Abstract

Cranioplasties show overall high complication rates of up to 45.3%. Risk factors potentially associated with the occurrence of postoperative complications are frequently discussed in existing research. The present study examines the positioning of 39 patient-specific implants (PSI) made from polyetheretherketone (PEEK) and retrospectively investigates the relationship between the fitting accuracy and incidence of postoperative complications. To analyze the fitting accuracy of the implants pre- and post-operatively, STL files were created and superimposed in a 3D coordinate system, and the deviations were graphically displayed and evaluated along with the postoperative complications. On average, 95.17% (SD = 9.42) of the measurements between planned and surgically achieved implant position were within the defined tolerance range. In cases with lower accordance, an increased occurrence of complications could not be demonstrated. The overall postoperative complication rate was 64.1%. The fitting of the PEEK-PSI was highly satisfactory. There were predominantly minor deviations of the achieved compared to the planned implant positions; however, estimations were within the defined tolerance range. Despite the overall high accuracy of fitting, a considerable complication rate was found. To optimize the surgical outcome, the focus should instead be directed towards the investigation of other risk factors.

Polyetheretherketone Implant Cranioplasty for Large Cranial Defects: A Seven-Year Follow-Up

“…In our study, mean operative duration and hospital stay were consistent with prior studies. 6,12,24 Furthermore, there was high intra-operative implant accuracy and implant re-shaping was performed with ease in the few cases when needed. There were similar outcomes in patients with 2-piece versus 1-piece implants which correlate to the size of the defect which is larger for 2-piece reconstructions.…”

“…In particular, computer-designed polyetheretherketone (PEEK) implant has gained traction as a preferred material used for cranioplasty. 2,4,6,[10][11][12][13][14][15][16][17][18] These patient-specific implants are designed from a thin slice computed tomography (CT) scan of the patient's skull and manufactured to precisely match the skull defect with an average accuracy of 2 mm. 9 Other advantages of PEEK implants include thermal conductivity, lightweight, stiffness, durability, lack of magnetic resonance which does not interfere with radiographic imaging, and easy intra-operative modification.…”

3D printing for bone regeneration: challenges and opportunities for achieving predictability

“…3D-printed titanium scaffolds have been used for skeletal augmentation in many studies, but none of the studies were designed to determine bony in-growth but used scaffolds for structural augmentation or contour reconstruction. 31,134,135 Although limited to case reports and small case series, there is promise in the utilization of titanium scaffolds not only for augmentation but also for craniofacial regeneration. Cicciu et al ( 2012) utilized a mandibular reconstruction plate for reconstruction of a segmental mandibulectomy defect in combination with a titanium mesh impregnated with BMP-2.…”

“…Metallic (mainly titanium) implants modified to incorporate a porous structure are being used in clinical settings to achieve not only skeletal continuity but also bony regeneration. 3D‐printed titanium scaffolds have been used for skeletal augmentation in many studies, but none of the studies were designed to determine bony in‐growth but used scaffolds for structural augmentation or contour reconstruction 31,134,135 . Although limited to case reports and small case series, there is promise in the utilization of titanium scaffolds not only for augmentation but also for craniofacial regeneration.…”

Post-Operative Evaluation of Accuracy of Three-Dimensional Virtual Planning in Reconstructive Craniofacial Surgeries

“…1), which also showed the size of the deviations. A 3D analysis application was used to calculate the quantitative values of the deviations using a similar coordinate system in each example (Moellmann et al, 2022). Statistical analysis of collected data after superimposition of STL files (Pre and Post) was done using SPSS v26 (IBM Inc., Chicago, IL, USA).…”