Aplicación clínica de la planificación virtual y la navegación en el tratamiento de las fracturas del suelo de la órbita / Clinical application of virtual planning and navigation for the treatment of the orbital floor fractures

El objetivo del tratamiento de las fracturas de órbita es reconstruir la forma tridimensional de las paredes orbitarias para restablecer el volumen orbitario y la función ocular. El enoftalmos y la diplopía producidos por la reconstrucción inapropiada de la anatomía orbitaria tras un traumatismo continúan siendo todavía una secuela de estas fracturas. El objetivo de este trabajo es describir la técnica de la planificación virtual y la navegación intraoperatoria en el tratamiento de fracturas de suelo y pared medial de la órbita como herramienta útil en el tratamiento de estas fracturas. La técnica de planificación virtual y navegación intraorbitaria se aplica para el tratamiento de pacientes con fracturas de suelo o pared medial de órbita. La corrección virtual de la órbita fracturada se realiza utilizando la imagen en espejo del lado sano superpuesta sobre el lado fracturado. La planificación preoperatoria permite, además, importar y seleccionar preoperatoriamnete una malla premoldeada y determinar la adecuación de esta, en forma y tamaño, para tratar la fractura. La navegación intraoperatoria permite la disección segura y adecuada del contenido orbitario («primera» navegación) y la confirmación de la adecuada reconstrucción de las paredes orbitarias («segunda» navegación). La planificación en ordenador, la cirugía virtual y la navegación intraoperatoria aportan una guía útil, precisa y segura para la reconstrucción orbitaria (AU)

The goal of the treatment of orbital fractures is to reconstruct the three-dimensional shape of the orbital walls to restore the orbital volume and eye function. Enophthalmos and diplopía caused by inappropriate orbital wall anatomy reconstruction after trauma, remain still a sequel to these fractures. The objectives of this paper are to describe the technique of virtual planning and intraoperative navigation in the treatment of floor and medial wall fractures of the orbit as a useful tool in the treatment of these fractures. We have applied the technique of virtual planning and navigation for the treatment of patients with fractures of floor and/or medial orbital wall. The virtual correction of the fractured orbit is performed using the mirror image of the healthy side superimposed on the fractured side. Preoperative computer planning also allows importing the object ‘premolded mesh' to the plan to determine its appropriateness, in shape and size, to treat the fracture. Intraoperative navigation allows a safe and proper dissection ('first' navigation) of the orbital contents and confirmed the proper reconstruction of the orbital walls ('second' navigation). Navigation allows a safe dissection of the orbital contents and a verification of the accuracy of the position of the mesh. Computer planning, virtual surgery and intraoperative navigation provide precise guidance and safety for orbital reconstruction (AU)

[Enophtalmos of the anophtalmic socket: incidence of the orbital morphology and therapeutic implications. Clinical study of 86 cases]. / Énophtalmie de la cavité anophtalme : incidence de la morphologie orbitaire et implications thérapeutiques. Étude clinique de 86 cas.

AIM OF THE STUDY: From a light asymmetry to a sunken eye aspect, a great disparity between the results after anophtalmic socket rehabilitation is noticeable: what are the factors involved in the degree of residual enophtalmos following excision of the eye? The litterature's response is based on physiopathological considerations around intraorbital architectural disturbance. We propose a geometrical approach related to the existence of different morphological types of orbit. PATIENTS AND METHOD: Eighty-six records of eviscerated and enucleated patients have been studied and submitted to a statistical analysis. A preliminary study has defined four types of orbit depending on the shape and operture of the orbital "window": two opposite types IA and III, a type II intermediate and a particular one, the type IB. A classification of enophtalmos' degree allows to analyze the parameters chosen and to identify the predictive factors. RESULTS: The statistical analysis confirms the incidence of the orbital morphology on the degree of enophtalmos but do not support the theories based on the intraorbital septal architecture changes. Depending on the orbital shape and the container-content relation, the volume loss is more visible on the whole orbitopalpebral surface of opened and high orbit but remains centered on the anteroposterior position of the implant of a closed and lengthened orbit. At the contrary to the type III, the type IA is not favorable for the anophtalmic patient and predispose to a higher degree of enophtalmos. This new approach has therapeutic implications on primary and secondary surgery for volume loss replacement. CONCLUSION: The success of anophtalmic socket rehabilitation is influenced by the orbital morphological type that has to be considered in the therapeutic strategy.

Use of porous polyethylene with embedded titanium in orbital reconstruction: a review of 106 patients.

PURPOSE: To evaluate our initial experience with a porous polyethylene implant with embedded titanium in orbital reconstruction. METHODS: A retrospective review of the charts was performed for patients receiving at least 1 orbital porous polyethylene implant with embedded titanium from October 2004 through April 2006. Patient demographics, implant type and size, method of fixation, postoperative complications, and length of follow-up were recorded. RESULTS: One-hundred six patients received at least one embedded titanium implant (80 men, 26 women). Age ranged from 3 years to 85 years (mean, 31 years). Indications included orbital fracture repair (102 patients), correction of enophthalmos (3 patients), and reconstruction after tumor resection (1 patient). The average floor implant used was 22.3 mm wide by 27.9 mm long. The average medial wall implant was 13.6 mm tall by 22 mm long. Implants were fixated with 1 or 2 microscrews in 75 patients (70.8%) and placed without fixation in 31 patients (29.2%). Four postoperative complications were noted: a retrobulbar hemorrhage on postoperative day 3 that resolved without sequelae, a vertical overcorrection requiring removal of the implant, a transient oculomotor disturbance, and a screw placed in proximity to the infraorbital nerve canal resulting in hypesthesia and chronic pain that required removal of the screw. In the 3 complications potentially related to the implant, the embedded titanium allowed postoperative implant visualization and guided subsequent management. No implant extrusions or postoperative infections were noted. CONCLUSIONS: Porous polyethylene implants with embedded titanium provide a new alternative to alloplastic implant materials for orbital reconstruction with a profile that combines several advantages of porous polyethylene and titanium implants.

[Dermis-fat graft. Possibilities and limitations]. / Dermis-Fett-TransplantatMöglichkeiten und Grenzen.

Various alloplastic orbital implants, preferably with a spherical configuration, are employed for the routine care of an enucleated socket. Alternately, an autologous dermis-fat graft can also be used. It represents a safe alternative to alloplastic orbital implants. The method does not require preserved sclera, thus excluding even theoretically possible transfer of pathogens such as viruses or prions in sclera preserved in alcohol. Loss of the transplant or other serious complications were only very rarely observed, late extrusion is unknown. Due to its high degree of safety concurrent with excellent functional and cosmetic results, the dermis-fat transplant is particularly advantageous for young patients. In cases of complicated orbits and contracted sockets the method of dermis-fat transplantation often represents the only promising option.