Advances address challenges of orbital fracture treatment

April 1, 2015

Several decades of advances in techniques and technology have enabled surgeons to improve the outcomes of treatment for orbital fractures.

 

Take-home message: Several decades of advances in techniques and technology have enabled surgeons to improve the outcomes of treatment for orbital fractures.

 

 

By Nancy Groves; Reviewed by Paul N. Manson MD, FACS

Baltimore-“We communicate with our eyes and rely on them for an index of what others are thinking,” said Paul N. Manson, MD. “If you don’t look normal, you can’t interact normally.

“Thus, the stakes are high with orbital fracture treatment,” explained Dr. Manson, professor of plastic and reconstructive surgery, Johns Hopkins University School of Medicine and the University of Maryland Shock Trauma Unit and a former program director of the plastic surgery residency program.

Summing up the major advances in management of orbital fractures witnessed over a career of 39 years, Dr. Manson identified five contributions that help surgeons achieve the dual goals of restoring both physiologic function and aesthetic appearance. They are:

  • The concept of orbital soft tissue and bone volumes.

  • The separation of orbital volume analysis from the analysis of injury to the extraocular muscle system.

  • The advent of computerized tomographic (CT) scanning.

  • The concept of orbital shape and restoration of the orbital buttress system.

  • The development of rigid fixation, computerized plates, and CT alignment of plates.

Timeline perspective

Early in his career, Dr. Manson noted he often had few sources of guidance when presented with patients who had serious orbital injuries. The textbooks of the time had limited information, and the tools of diagnosis during the 1970s were physical examination, plain radiographs, and surgical exploration.

The mechanism of traumatic enophthalmos had been studied, and it was known that the globe was driven back into the orbit, with the impact on the walls causing the fracture.

“A number of people latched onto the concept of volume,” Dr. Manson said.

Surgeons began studying how to move the globe forward and devising new methods of performing bone grafts, such as using the buttress system of the orbit as a template for reconstruction.

When CT scanning was introduced in the 1980s, it was revolutionary for providing images not only of the anatomy of bone fractures, but also the position of other key structures-such as extraocular muscles or the location of hematomas.

“The more you stare at your CT scans, the more you’re going to figure out things that at first were not apparent to you,” Dr. Manson said.

One of the things he learned from reviewing CT images was that soft tissue disorganization may occur with a fracture. Prolapsed tissue that was originally behind the globe becomes external to the extra muscular cone. Dr. Manson and others determined that fat atrophy did not normally occur in blowout fractures and studied methods of restoring this material to its proper position.

As correction techniques advanced, surgeons began using not only bone grafts, but also titanium plates to stabilize orbital fractures.

Another major contribution in orbital surgery came from Allen Putterman, MD.

“What he really started was the idea that you should separate the analysis of the muscle injury from the volume change,” Dr. Manson said.

It was learned that a musculofibrous ligament system extends throughout the orbit, running through the fat and connecting all the extraocular muscles with the walls of the orbit and the globe. In blowout fractures, an extraocular muscle can be incarcerated by trapping the system or the fat. Generally, this is preferable to trapping the extraocular muscle itself.

Other surgeons investigated the theory of an orbital muscle compartment syndrome. However, it was eventually concluded that unlike lower extremities, extraocular muscle has no dense fascia, and therefore, it is impossible to produce compartment syndrome there.

“The mechanisms of diplopia which are surgically correctable are a possible change in origin of muscle, because of its adherence or entrapment, change in path or sagging of this muscle, and then true musculofibrous ligament incarceration and more rarely incarceration of the muscle itself,” Dr. Manson said.

Several papers explored the correlation of enophthalmos and diplopia with rounding of extraocular muscles in CT scans, theorizing that it must be related to disruption of the ligaments that keep that muscle in an elliptical shape. It was subsequently proven that a “sagging” muscle, one with an abnormal or misaligned path, could itself cause double vision.

Orbital shape is a crucial concept in reconstructive surgery. The shape is predicted by the subtle curves and the precise reconstruction of the buttress system, and the curves of the orbital walls have to be reproduced to get the best aesthetic result, according to Dr. Manson. His advice is to find the intact portion of the orbit and try to reconstruct the missing area as accurately as possible.

“We’ve learned to avoid in orbital incisions the critical area of the lower lid: the junction of the anterior lamella, tarsal plate, and posterior lamella,” he said. “If you keep your incision outside of that area you avoid damaging the pre-tarsal orbicularis, weakening the nerve and creating fibrosis, both of which give you upward support of the lid with orbicularis contraction.”

He also stressed the importance of realigning the soft facial tissue on the bone as it was pre-injury; the facial soft tissue will sag if not properly reattached to the facial skeleton.

Three-dimensional modeling and segmental analysis can decrease frustration in achieving orbital fracture alignment, Dr. Manson noted. Since about 90% of patients are relatively similar in the parts of the orbit that fracture, orbital fracture defects can be organized into several common patterns and treated with three different sized and shaped plates.

Significant improvements in plate design and application have occurred as new generations of surgeons have completed training and built on the work of earlier colleagues.

 

Paul N. Manson MD, FACS

E: pmanson@jhmi.edu

P: 410/955-9469

This article was adapted from Dr. Manson’s presentation of the Helen Keller Lecture at the 2014 meeting of the American Academy of Ophthalmology. Dr. Manson has no financial interests or relationships to disclose.