Time-Dependent Changes in Resorbable Implants for Orbital Wall Fractures: Evaluation Using Orbital Volume...

Area of Science:

• Biomaterials Science
• Craniofacial Surgery
• Medical Imaging

Background:

• Resorbable implants are utilized for orbital wall fracture repair, offering temporary support.
• Long-term effects of implant resorption on orbital morphology remain incompletely understood.
• Evaluating different resorbable materials is crucial for predicting post-surgical outcomes.

Purpose of the Study:

• To compare the long-term volumetric changes of orbital reconstructions using two distinct resorbable plate types.
• To assess the stability of orbital morphology following repair with uncalcined hydroxyapatite/poly-L-lactic acid (u-HA/PLLA) versus poly-L-lactic acid/polyglycolic acid (PLLA/PGA) implants.
• To investigate the correlation between orbital volume changes and enophthalmos.

Main Methods:

• Retrospective analysis of 30 patients with fresh orbital wall fractures.
• Computed tomography (CT) scans were used for orbital volume measurements at preoperative, early postoperative, and late postoperative (≥4 months) time points.
• Mimics software calculated orbital volumes; ocular protrusion assessed enophthalmos.

Main Results:

• The u-HA/PLLA group demonstrated stable orbital volumes post-surgery (mean difference decreased from 2.30 cm³ to 1.10 cm³ and remained at 1.17 cm³).
• The PLLA/PGA group showed initial improvement followed by significant volumetric regression during follow-up.
• A significant correlation (P=0.004, R²=0.260) was found between orbital volume differences and enophthalmos.

Conclusions:

• PLLA/PGA implants may lead to orbital morphologic regression over time.
• u-HA/PLLA implants provide more stable long-term orbital volume maintenance.
• Implant selection for orbital reconstruction should prioritize long-term mechanical integrity for sustained clinical success.