Endoscopic endonasal repair with polyethylene implants in medial orbital wall fractures: A prospective study on 25 cases

Probing real-world Central European population midfacial skeleton symmetry for maxillofacial surgery

OBJECTIVES

Symmetry is essential for computer-aided surgical (CAS) procedures in oral and maxillofacial surgery (OMFS). A critical step for successful CAS is mirroring the unaffected side to create a template for the virtual reconstruction of the injured anatomical structure. The aim was to identify specific anatomical landmarks of the midfacial skeleton, to evaluate the symmetry in a group of the real-world Central European population, and to use these landmarks to assess midfacial symmetry in CT scans.

MATERIAL AND METHODS

The retrospective cross-sectional study defined landmarks of the midface's bony contour using viscerocranial CT data. The distances of the skeletal landmarks (e.g., the frontozygomatic suture and temporozygomatic suture) of the left and right sides from the midline were measured and statistically compared. Midfacial symmetry for reference points was defined as a difference within 0 mm and their mean difference plus one standard deviation.

RESULTS

We examined a total of 101 CT scans. 75% of our population shows symmetrical proportions of the midface. The means of the differences for the left and right sides ranged from 0.8 to 1.3 mm, averaging 1.1 ± 0.2 mm for all skeletal landmarks. The standard deviations ranged from 0.6 to 1.4 mm, with a computed mean of 0.9 ± 0.3 mm.

CONCLUSION

We established a methodology to assess the symmetry of the bony midface. If the determined differences were equal to or lower than 2.5 mm in the mentioned midfacial skeletal landmarks, then the symmetry of the bony midface was considered present, and symmetry-based methods for CAS procedures are applicable.

CLINICAL RELEVANCE

Many CAS procedures require facial symmetry. We provide an easy-to-apply method to probe for symmetry of the midface. The method may be used for population-based research, to check for proper reduction of fractures after reposition or to screen for symmetry prior to CAS planning.

Navigational Transmaxillary Endoscopic Approach for Inferomedial Tumors

Orbital tumors encompass a heterogeneous range of histopathology and usually variable in location. Traditionally, transconjunctival medial orbitotomy is used to access the medial orbital wall. However, it creates potential risk of soft tissue sequelae such as scarring, lid contracture, or entropion/ectropion. For the lesions close to the orbital apex, increased risk of optical nerve injury should be cautious during orbitotomy procedure. Transnasal endoscopic approach to the orbital walls has been applied since 1999. Although it provides good surgical visualization and prevents the soft tissue and neural complications, the narrow nasal corridor increases the surgical complexity. Extensive sphenoethmoidectomy is usually required to gaining access. Furthermore, the resultant medical orbital defect is difficult to repair. The maxillary sinus is the largest paranasal sinuses which is located beneath the orbital floor. It provides an ample working space for instrumentation. Meanwhile, repair of the orbital floor defect is feasible and with high degree of accuracy under navigation control. In this report, we propose a novel computer-assisted endoscopic protocol to excise the medial orbital tumors with immediate repair of the wall defect.

Repair of unilateral combined orbital floor and medial wall fracture using two titanium mesh plates: a modified technique

Background

Compared to isolated orbital wall fracture, combined orbital floor and medial wall fractures are more likely to be required surgical correction due to a higher possibility of complications. However, it remains a challenge to repair concomitant orbital fracture using a one-piece implant due to the complex anatomic structures of the orbit. Aiming to reduce surgical difficulties and enhance therapeutic effects, we repaired unilateral combined orbital floor and medial wall fractures using two separated modified titanium mesh plates in this study.

Methods

A retrospective study was conducted on 21 consecutive patients who presented with unilateral combined orbital floor and medial wall fractures in Tianjin Medical University General Hospital between November 2010 and January 2016. The orbital fractures were repaired with two separated titanium mesh plates. The corner at the transition zone area between the orbital floor and the medial wall was reconstructed simultaneously through a combined transcaruncular and inferior subciliary approach with lateral canthotomy. The pre- and post-operative functions and aesthetic results were evaluated.

Results

Preoperatively, all patients presented with 3.5-6.5 mm enophthalmos, five patients presented with diplopia with ocular motility limitation in injured eyes, and six patients presented with hypoglobus ranging from 1.5 to 3.5 mm. Orbital floor and medial wall fractures of all patients were successfully repaired with two separated titanium mesh plates. Postoperatively, enophthalmos was improved in all patients, which was less than 2 mm on the last follow-up day. Hypoglobus was disappeared in all six patients postoperatively. Diplopia was resolved in five patients within 3 months post operation, and was reduced in one patient.

Conclusions

In cases of unilateral concomitant orbital floor and medial wall fractures, two titanium mesh plates implantation is a safe and effective procedure. It is worthwhile to take the technique into account when the key points to consider when applying this method include reconstruction of the special orbital shape and the complete return reposition of prolapsed intraorbital soft tissues were intended.

Retrobulbar Orbital Emphysema Associated With Medial Orbital Wall Fracture

Retrobulbar emphysema is a rare condition compared to the more common orbital emphysema. It is often associated with medial orbital wall fracture with rupture of the periosteum. In some severe patients, retrobulbar emphysema can increase the intraorbital pressure and lead to orbital compartment syndrome. Less extreme patients require only conservative treatment with careful observation. There is still no standard protocol for the management of orbital emphysema in general or specifically for retrobulbar emphysema. Visual acuity is the most widely used indicator to determine whether surgical intervention is needed. The patient presented here suffered from large retrobulbar intraconal emphysema and exophthalmos without visual loss after head trauma and nose blowing. He was observed closely without surgical intervention. After the emphysema had resolved, the patient's medial orbital wall defect was reconstructed using unsintered hydroxyapatite particles/poly L-lactide via the transcaruncular approach. The postoperative course has been uneventful with more than 1 year of follow-up to date.

Extent of Inflammation and Foreign Body Reaction to Porous Polyethylene In Vitro and In Vivo

BACKGROUND/AIM

High-density porous polyethylene (PP) offers possibilities for reconstruction in craniofacial surgery. The purpose of this study was to evaluate the extent of inflammation and foreign body reactions to PP in vitro and in vivo.

MATERIALS AND METHODS

Cell attachment, proliferation and expression of inflammatory cytokines were assessed using murine macrophages (RAW 264.7) on two different PP materials in vitro. In vivo, Balb/c mice received PP implants at their dorsum. After sacrifice, samples were analyzed histologically and real-time PCR was used to assess expression of inflammatory cytokines.

RESULTS

Cells showed a significantly decreased proliferation (p<0.001) after 48 h and a significantly increased expression of TNF-α (p<0.05) at 24, 48 and 72 h. All animals showed foreign body cell reactions and signs of chronic inflammation. Expression of all but one of the investigated cytokines dropped to non-significant levels after an initial increase.

CONCLUSION

Application of porous polyethylene can cause local chronic inflammatory reactions. Although clinical application seems to be immunologically safe, indication and risks should be evaluated carefully when using PP implants.

Navigation-Assisted Isolated Medial Orbital Wall Fracture Reconstruction Using an U-HA/PLLA Sheet via a Transcaruncular Approach

Purpose: We investigated the feasibility of isolated medial orbital wall fracture reconstruction using an unsintered hydroxyapatite particles/poly L-lactide (u-HA/PLLA) sheet implant with the assistance of intraoperative navigation via the transcaruncular approach. Patients and methods: Ten consecutive patients (5 males and 5 females; mean age, 57.5 years) were included based on the clinical and imaging criteria. All patients underwent surgical treatment of the isolated medial orbital wall fracture using transcaruncular incision and the u-HA/PLLA implant under navigation. The follow-up time was greater than 6 months. Preoperative and postoperative clinical data regarding the presence of diplopia, eye motility restriction, and enophthalmos were assessed. The orbital volumes of the injured and uninjured orbit were also evaluated using computed tomography images. Results: All patients had improved ophthalmologic functional and esthetic outcomes and were successfully treated without any long-term complications arising during follow-up. There was a significant difference between the preoperative and postoperative injured orbits due to herniation of the orbital contents. Moreover, the orbital volume of the postoperative injured side following surgery was the same as that of the unaffected side, indicating that anatomically good reconstruction had been obtained. Conclusions: Surgical treatment using the transcaruncular approach and u-HA/PLLA materials with intraoperative navigation is a safe, promising, and effective technique for isolated medial orbital wall fracture reconstruction.

Development of Chronic Sphenoid Sinusitis After Sellar Reconstruction with Medpor Porous Polyethylene Implant

OBJECTIVE

The Medpor porous polyethylene implant is reported to be safe and effective for sellar reconstruction after transsphenoidal surgery (TSS). However, we have observed several cases of delayed chronic sphenoid sinusitis related to the implant. The purpose of this study is to describe the presentation and management of implant-related sphenoid sinusitis after sellar reconstruction.

METHODS

This is a retrospective study of patients who underwent endonasal TSS with Medpor sellar reconstruction between December 2008 and January 2013 at a tertiary care institution. Patient demographics, initial surgical management, sinonasal symptoms, postoperative imaging, sinusitis management, and resulting outcomes were analyzed.

RESULTS

From 2008-2013, 139 patients underwent sellar reconstruction using Medpor. Five patients (3.6%) presented between 8 and 60 months after surgery with chronic sphenoid sinusitis that required surgical management. All 5 patients presented as outpatients for management of headaches and nasal drainage, 4 patients experienced chronic nasal congestion, and 3 patients noted recurrent sinusitis. At the time of revision surgery, all 5 patients were found to have mucosal inflammation and edema surrounding the implant, and 4 of the 5 had an exposed or partially extruded implant that was removed.

CONCLUSIONS

Reconstruction of the sellar floor may be performed after TSS to prevent postoperative complications. Although porous polyethylene implants have previously been described as safe and effective for this purpose, surgeons should be aware of the risk of subsequent implant extrusion and chronic sphenoid sinusitis that can occur in a delayed manner.