Efficiency of 3D-printed Implant Versus Autograft for Orbital Reconstruction (TOR-3D)

Evaluation of the Efficiency for Orbital Reconstruction After Defect of Bone Substance by Three-dimensional Printed Patient Specific Porous Titanium Implant in Comparison With Autologous Bone Graft

Two scenarios may result in significant bone defect in the orbit: surgical oncology (meningioma, cancers of the upper aerodigestive tract) or severe trauma. This defect in the bone substance may affect the orbital floor, medial wall or lateral wall. These injuries can result in functional complications such as enophthalmos and diplopia, and an esthetic impact affecting the quality of life. The most frequent complication in orbital traumas is enophthalmos (10-20% according to publications).

The aim of bone substance reconstruction is to restore the volume and the internal shape of the orbit. The gold standard is autologous bone grafts. The surgery which usually lasts 2 to 3 hours depending on the number of walls involved, can lead to ophthalmological or esthetic complications. Its results are unsatisfactory, and the use of titanium implants would allow a reconstruction of the orbital volume more optimal than the autograft.

The development of computer-assisted techniques permitted implants evolution: initially peri-operatively preformed, today patient specific implant can be obtained from data of CT-scan. In cranioplasties, a randomized study showed better results at 12 months of these implants compared to the autograft. Their success rate is close to 100% with less than 5% of postoperative complication, while the rate used for cortical graft reconstructions is 20-25%.

Today, 3D printing of patient-specific porous titanium implants is possible. A study has shown that they allow a more accurate reconstruction compared to preformed implants. This innovation is available in France but it has a high cost (2,000 euros on average) and is currently not refunded. However, the use of this technology would reduce the operating time and the morbidity per- and post-operative, with functional and esthetic results superior to those obtained with bone autograft.

Inclusion Criteria:

• Patient between 18 to 90 years old
• Presenting a defect in the bone substance of an orbital wall (floor, lateral or medial): at least 6 months following a oncologic surgery (in particular meningioma or carcinoma of the upper aerodigestive tract) OR post-traumatic;
• With a defect of the unilateral orbital bone substance described as complex on the CT-scan: fracture in the posterior third of one walls; fracture extended to two walls (floor and lateral wall, or medial wall and orbital floor); comminutive fracture of at least one of the walls; fracture with more than half of one of the walls tipped over;
• Presenting an enophthalmos ≥ 3 mm OR an enophthalmos ≥ 2mm with diplopia;
• Patient with a programmed orbital reconstruction;
• For patients who have had oncologic surgery, validation of a multidisciplinary consultation meeting;
• Whose contralateral orbital anatomy is healthy (absence of : bone defect, diplopia, ptosis or other condition affecting aesthetics);
• Patient who gave its written informed consent to participate to the study;
• Affiliated to a social insurgence regime or similar.

Exclusion Criteria:

• Defect of bone substance extended to the upper and / or intermediate floors of the skull-base;
• For patients who have undergone oncologic surgery, patients with uncontrolled cancer proliferation;
• Defect of bone substance from the skull vault;
• Osteo-meningeal Breach;
• Patient whose understand the French questionnaire EQ-5D-3L;
• Follow up not possible during 18months (judgement of investigator)
• Patient with hypersensitivity to metallic materials;
• Major patient protected by the Law;
• Pregnant or breastfeeding woman