Ứng dụng thiết bị định vị trong tái tạo ổ mắt phức tạp Surgical navigation in complex orbital reconstruCTion

Orbital reconstruction is one of the most accuracy-dependent areas of maxillofacial trauma surgery.

The surgical field is narrow, deep, and often difficult to visualize completely. In extensive fractures, particularly when large portions of the orbital floor or medial wall are destroyed, normal anatomical landmarks may be severely distorted or absent.

In these situations, accurately defining the limits of the defect and the position of the reconstructive material becomes considerably more challenging.

Surgical navigation can assist by allowing the surgeon to identify the real-time position of an instrument within the patient's three-dimensional imaging data.

The objectives of orbital reconstruction

Orbital trauma can alter orbital volume, globe position, and the relationship of the surrounding soft tissues.

When the orbit becomes enlarged, the globe may displace posteriorly and inferiorly, producing enophthalmos or facial asymmetry. Orbital fat and extraocular muscles may also prolapse or become entrapped within the fracture, potentially resulting in restricted ocular movement and diplopia.

Orbital reconstruction is therefore not simply a matter of covering a bony defect. The objectives are to release entrapped tissues when indicated, restore orbital shape and volume, recreate the necessary skeletal boundaries, and return the globe to an appropriate position while preserving ocular function.

In relatively limited fractures, preserved bony landmarks may provide sufficient guidance for accurate reconstruction. In extensive trauma, however, direct visualization alone may not always provide enough spatial information.

When anatomical landmarks are largely lost

The patient in this case had sustained severe polytrauma with an extensive right orbital defect.

The orbital floor was almost completely disrupted, leaving few reliable anatomical landmarks on which to position the reconstructive material.

The patient had previously undergone orbital reconstruction, but significant right-sided enophthalmos remained after surgery.

On reassessment, the position of the titanium mesh suggested that the previous reconstruction had not fully restored the intended orbital geometry and volume.

In such a situation, the challenge is not simply to place additional material. The more important question is where the orbital floor and walls should actually be reconstructed in an orbit that has already been extensively distorted.

This is where surgical navigation can become particularly valuable.

Real-time spatial verification

Preoperative CT data were used to define the anatomy and plan the reconstruction.

During surgery, after registration of the patient with the navigation system, the position of the surgical instrument could be displayed in real time on multiplanar imaging and three-dimensional datasets.

This allowed the surgeon to verify the position of both the instrument and the reconstructive material in deep regions that were difficult to assess directly.

It was possible to confirm whether the posterior extent of the orbital floor had been reached, whether the reconstructive material followed the intended anatomical contour, whether the margins of the defect had been adequately covered, and whether any part of the titanium mesh was positioned too low, too high, or outside the intended reconstruction.

Navigation does not replace surgical skill or anatomical knowledge. Its value lies in providing an additional layer of spatial information in regions that are deep, narrow, and difficult to assess by direct vision alone.

Secondary orbital reconstruction

During revision surgery, two titanium meshes were used to reconstruct the right orbit.

Their positions were progressively checked with surgical navigation in an effort to reproduce the intended orbital shape and volume as accurately as possible.

The objective was not simply to push the globe anteriorly. Rather, it was to restore the geometry of the orbit so that the globe could return to a more appropriate position within a correctly reconstructed orbital cavity.

At one month after surgery, the enophthalmos had improved substantially and orbital symmetry was noticeably better than before revision.

This remains an early postoperative result, but the initial improvement demonstrates the value of restoring orbital anatomy more accurately.

Navigation does not replace the surgeon

Not every orbital fracture requires surgical navigation.

Many orbital injuries can be reconstructed accurately using conventional techniques when reliable anatomical landmarks remain and the extent of the defect is limited.

Navigation becomes particularly useful in extensive orbital defects, loss of normal landmarks, multi-wall fractures, secondary reconstruction after previous surgery, or when implant position must be verified in deep regions that are difficult to visualize directly.

In these situations, navigation helps the surgeon confirm spatial information that cannot be fully appreciated by direct vision alone.

Technology is valuable when it solves a clinical problem

The value of technology in surgery is not simply that it makes a procedure appear more advanced.

Its value lies in solving a specific clinical problem: how to accurately reconstruct a three-dimensional structure when the normal anatomical landmarks have been destroyed or distorted.

In orbital surgery, where relatively small errors in contour or implant position can alter orbital volume and globe position, real-time spatial verification can be a particularly useful tool.