Experience with PEEK Clamp Fixation of Custom Porous Hydroxyapatite Implants in Cranioplasty: A Preliminary Single-Center Feasibility Case Series

Background: Cranioplasty using porous hydroxyapatite (PHA) implants is an established technique for cranial reconstruction due to its favorable osteointegration properties. However, the intrinsic fragility of PHA implants before complete osteointegration may limit the use of conventional rigid fixation systems. Although non-absorbable sutures remain the manufacturer-recommended fixation method, alternative fixation strategies have been proposed to improve implant stability during the early postoperative period. Methods: This retrospective single-center case series describes our preliminary clinical experience with a polyether-ether-ketone (PEEK) clamp fixation system (Cranial LOOP®) used in combination with customized porous hydroxyapatite implants. Seven consecutive patients undergoing cranioplasty between January and December 2019 were included. Clinical follow-up, postoperative imaging, implant stability, fixation-related complications, and cosmetic outcomes were retrospectively reviewed over a median follow-up period of 48 months. Results: All implants were satisfactorily positioned on immediate postoperative CT imaging, and no fixation-related displacement or implant fracture was observed during follow-up. No patient required revision surgery because of fixation failure. Radiological follow-up demonstrated progressive bone integration at the implant margins in 6/7 patients (85.7%). Cosmetic outcomes were generally satisfactory according to clinical assessment, although interpretation of these findings is limited by the subjective evaluation method and the absence of blinded assessment. Conclusions: This preliminary retrospective case series suggests that fixation of customized porous hydroxyapatite implants using Cranial LOOP® is technically feasible. Owing to the small sample size, retrospective design, lack of a control group, and subjective outcome assessment, no conclusions regarding comparative safety, mechanical superiority, or clinical effectiveness can be drawn. Larger prospective comparative studies are required to further evaluate this fixation strategy.