PEEK patient-specific implants for orbital reconstruction: accuracy and clinical outcomes

Orbital fractures represent a common and complex challenge in maxillofacial surgery, with functional and aesthetic sequelae. Advances in computer-aided design and manufacturing, virtual planning, and three-dimensional printing have enabledpatient-specific implants (PSIs). Polyetheretherketone (PEEK), a bioinert polymer with properties similar to cortical bone, has emerged as a suitable material for orbital reconstruction. Surgical navigation has also been advocated to enhance accuracy in challenging regions. This retrospective service evaluation analysed ten patients with unilateral orbital fractures reconstructed using customised PEEK PSIs, placed either with navigation (n = 5) or freehand (n = 5). Orbital volumes were measured preoperatively, after virtual planning, and postoperatively; implant positioning was assessed by translational and rotational deviations; and clinical outcomes were evaluated using standardised ophthalmic and maxillofacial criteria. Fractured orbits were larger than contralateral orbits preoperatively, with postoperative volumes close to those of the intact side in both groups. Planned-treated volume discrepancies were small (navigation median 1.50 cm³, IQR 0.30-1.60; freehand 0.20 cm³, IQR 0.20-0.50; median difference 1.00 cm³, 95% CI -0.30 to 1.60; p = 0.151). Translational deviations remained below 2 mm, while rotational discrepancies were greater without navigation, though not statistically significant. Clinical success was achieved in six of the nine evaluable patients, with persistent diplopia in three cases attributed to traumatic muscle injury rather than implant malposition. PEEK PSIs provided a reliable orbital reconstruction, accurate volume restoration, and favourable clinical outcomes. Customised PEEK PSIs were typically designed and manufactured within 4 weeks after clinical assessment and imaging, consistent with a delayed reconstruction pathway in complex cases. Navigation may enhance intraoperative confidence and refine rotational control; however, no statistically demonstrable advantage over freehand placement was shown in this small exploratory cohort, in which satisfactory outcomes were achieved with both approaches, consistent with the inherent 'one-fit' characteristic of PSI.