Two-Year Follow-up on the Use of Absorbable Mesh Plates in the Treatment of Medial Orbital Wall Fractures

Abstract

Background: Absorbable materials offer many advantages in the reconstruction of orbital walls; however, the possibility of postoperative enophthalmos after complete absorption cannot be excluded. We evaluated the postoperative results of absorbable mesh plates used as onlay implanting on the medial orbital wall to determine whether they are suitable for medial orbital wall reconstruction.

Methods: The study included 20 patients with medial orbital wall fractures who were followed up for more than 2 years postoperatively. We used absorbable mesh plates in all of the patients. We measured the following: the changes in the expanded orbital volume by comparing the preoperative and postoperative computed tomography (CT) scans and the degree of clinical enophthalmos.

Results: There were no major complications associated with the use of absorbable materials such as infection, migration, or extrusion of mesh plates during the long-term follow-up. The orbital volumetric changes between the preoperative and postoperative CT scans were not statistically significant. However, the expanded orbital volume was not related to the degree of clinical enophthalmos.

Conclusions: The reconstructed orbital wall may provide supportive scar tissue to the orbital contents even after the absorbable materials have dissolved completely. Absorbable mesh plates could be another option for the reconstruction of the medial orbital wall.

Keywords: Absorbable implants; Follow-up studies; Orbital fractures.

Fig. 1

Calculation of herniated orbital volume (A, B) The herniated orbital volume through the medial orbital wall defect was measured using the formula πabc/6, assuming that the shape of the dislocated tissue was hemi-ellipsoid. a, the height of the medial orbital wall defect; b, the length of the medial orbital wall defect; c, the degree of medial displacement of the herniated orbital tissue.

Fig. 2

The location of the medial rectus muscle The medial rectus muscle (white arrow) was located at the homologous position in the reconstructed orbit and the normal orbit, and a vague shadow of the scar band (dotted white arrow) was observed between the medial rectus muscle and the reconstructed medial orbital wall.

Fig. 3

Case 1, medial orbital wall reconstruction (A) Preoperative computed tomography (CT) showed a medial orbital wall fracture on the left side. (B) An immediate postoperative CT scan. The absorbable mesh plate was located in an adequate position. (C) Postoperative CT at the 2-year follow-up showed a well healed medial orbital wall, but both orbits showed asymmetry. (D) Nine days after trauma, swelling subsided and mild enophthalmos was detected. (E) Clinical photograph at the 2-year follow-up showed that enophthalmos was corrected.

Fig. 4

Case 2, medial orbital wall reconstruction (A) Preoperative computed tomography (CT) showed a medial orbital wall fracture on the right side. (B) Postoperative CT at the 2-year follow-up showed a well healed medial orbital wall, but both orbits showed asymmetry. (C) Eight days after trauma, swelling had subsided and mild enophthalmos was detected. (D) Clinical photograph at the 2-year follow-up showed mild enophthalmos of 2 mm, but the patient was satisfied with the results.

Fig. 5

Degradation rate of absorbable materials An Inion mesh plate degrades at an adequate rate compared to fast-absorbing polyglycolide polymer and slow-degrading poly-L-lactide polymer material.

Fig. 6

The bony buttress on coronal view The bony buttress is identical to the superior medial wall of maxillary sinus. This structure is the bony septum between the maxillary and the ethomoid sinus (arrow). The bony buttress is an important structure to support the medial and inferior orbital walls.