Resorbable Implants for Orbital Fractures: A Systematic Review

The impact of polydioxanone (PDS) foil thickness on reconstruction of the orbital geometry after isolated orbital floor fractures

PURPOSE

The orbital floor is frequently involved in head trauma. Current evidence on the use of reconstruction materials for orbital floor repair is inconclusive. Accordingly, this study aimed to compare the impact of polydioxanone (PDS) foil thickness on reconstruction of the orbital geometry after isolated orbital floor fractures.

METHODS

Standardized isolated orbital floor fractures were symmetrically created in 11 cadaver heads that provided 22 orbits. PDS foils with thicknesses of 0.25-0.5 mm were inserted. Computed tomography (CT) scans of the native, fractured, and reconstructed orbits were obtained, and orbital volume, orbital height, and foil bending were measured.

RESULTS

Orbital volume and height significantly (p < 0.01) increased after the creation of isolated orbital floor fractures and significantly (p = 0.001) decreased with overcorrection of the orbital geometry after orbital floor reconstruction with PDS 0.25 mm or PDS 0.5 mm. The orbital geometry reconstruction rate did not differ significantly with respect to foil thickness. However, compared to PDS 0.5 mm, the use of PDS 0.25 mm resulted in quantitatively higher reconstructive accuracy and a restored orbital volume that did not significantly differ from the initial volume.

CONCLUSION

Orbital floors subjected to isolated fractures were successfully reconstructed using PDS regardless of foil thickness, with overcorrection of the orbital geometry. Due to its lower flexural stiffness, PDS 0.25 mm appeared to provide more accurate orbital geometry reconstruction than PDS 0.5 mm, although no significant difference in reconstructive accuracy between PDS 0.25 mm and PDS 0.5 mm was observed in this cadaveric study.

Assessing effectiveness of endoscope-assisted medial orbital wall fracture repair vs. no surgery using benefit-risk metrics and literature review

PURPOSES

To evaluate clinical usefulness of endoscope-assisted medial orbital wall fracture repair via the retrocaruncular approach (rc-EAMOWFR) vs. no surgery (NS), and to perform a narrative review of relevant literature.

METHODS

This was a retrospective cohort study enrolling isolated medial orbital wall fracture (IMOWF) eyes presented to two German level 1 trauma centers during a 7-year interval. The predictor variable was treatment type (rc-EAMOWFR vs. NS), and the main outcomes were late enophthalmos (LE) and retrobulbar hemorrhage (RH) assessed at 9-15 posttraumatic months. Descriptive and bivariate statistics were computed at α = 95%. Binary adjustments enabled calculation of number needed to treat (NNT), to harm (NNH), and likelihood to be helped or harmed (LHH) for demonstrating benefit-risk tradeoffs. Moreover, a narrative review was also performed.

RESULTS

The sample comprised 502 patients (28.3% females; mean age, 46.5±19.2 years) with 541 IMOWF eyes (5.9% NS; 7.2% LE; 1.3% RH). Operated eyes had significantly lower LE events than NS eyes (symptomatic IMOWF: P < .0001; 95% confidence interval [CI], .03 to .16; NNT = 2 [95% CI, 1.1 to 6.1]; asymptomatic IMOWF: P < .0001; 95% CI, .01 to .07; NNT = 2 [95% CI, 1.1 to 1.8]). There were 7 (1.5%) RH events following rc-EAMOWFR (P = .99; 95% CI, .06 to 17.4; NNH = 68 [95% CI, 38.3 to 254.2]). LHH calculations posited that rc-EAMOWFR was 34 times more likely to prevent LE than to cause RH, regardless of fracture symptoms. Our results conformed to those of other 15 studies.

CONCLUSIONS

The results of this study suggest that all IMOWFs be treated. rc-EAMOWFR performed in every 68 IMOWFs would be at risk of one RH event, but prevent 34 eyes from LE due to untreated fractures. Nearly 72% of untreated IMOWFs develop LE after 9 months.

Orbital Soft Tissue Displacement After Blow-Out Fracture Repair Using Poly (L-Lactide-Co-Glycolide) Polymer Plates Based on Image Fusion Technique

PURPOSE

To analyze the displacement of orbital soft tissue after blow-out fracture (BOF) repair with poly (L-lactide-co-glycolide) plates.

MATERIALS AND METHODS

In this retrospective study, all patients who had undergone repair operations for orbital BOF from 2017 to 2021 were evaluated. Poly (L-lactide-co-glycolide) plates were used as repair materials. Preoperative and postoperative computed tomography images were integrated into the same coordinate system applying image fusion technique and were compared to determine the maximum displacement of orbital tissue after surgical repair.

RESULTS

A total of 15 patients were included. Five were male, and 10 were female. Mean age was 33±16 years. Median waiting period was 18 (12-23) days. Six cases were medial wall fractures, 5 were floor fractures, and 4 were combined fractures. Maxillo-ethmoidal strut was involved in 4. Mean defect area was 176.52±108.48 mm 2 . Median interval between postoperative imaging examinations was 292 (223-600) days. Mean orbital tissue displacement was 2.6±1.8 mm. Using simple and multivariable linear regression analysis, the fracture defect area ( P =0.001) and maxillo-ethmoidal strut involvement ( P =0.013) were found to be significantly associated with orbital tissue displacement. Median orbital volume change was 0.804 (0.647-1.010) cm 3 . Average proptosis variation was 1.2±0.8 mm.

CONCLUSIONS

Poly (L-lactide-co-glycolide) plates were more suitable for orbital BOF with small defect size. Those with large defect or maxillo-ethmoidal strut involved might have greater tissue displacements due to decline of supporting strength of poly (L-lactide-co-glycolide) plates.

Quantitative assessment of increase in orbital volume after orbital floor fracture reconstruction using a bioabsorbable implant

PURPOSE

To assess the postoperative changes in the orbital volume and the degree of enophthalmos after orbital floor fracture reconstruction using a bioabsorbable implant and to determine the predictors of postoperative orbital volume change.

METHODS

Single-center, retrospective case series of 16 patients who underwent orbital floor fracture reconstruction using a bioabsorbable implant [poly(L-lactic acid)-poly(glycolic acid)/β-tricalcium phosphate; Biobsorb β^®] were included. Three-dimensional volumetric calculations of orbit were determined using computed tomography scans and the degree of enophthalmos was assessed via Hertel exophthalmometry. Postoperative changes in the orbital volume and the degree of enophthalmos and their correlation were assessed.

RESULTS

The mean volume of fractured orbits immediately after surgery was 22.26 ± 1.98 cm³, increasing to 23.67 ± 2.00 cm³ at 6-month follow-up (p < 0.001); the increased orbital volume was associated with postoperative deformation of the implant. The mean degree of enophthalmos was 0.09 ± 0.27 mm at 1-month follow-up, which increased to 0.66 ± 0.30 mm at 6-month follow-up (p = 0.001). Increase in orbital volume and enophthalmos progression showed a linear correlation (R = 0.682, p = 0.004). Patients with more herniated orbital tissue preoperatively showed increased postoperative orbital volume change (p = 0.015), whereas the size of the fracture area was not predictive of postoperative orbital volume change (p = 0.442).

CONCLUSION

Increase in orbital volume by deformation of the bioabsorbable implant resulted in progressive enophthalmos during the postoperative follow-up period after orbital floor fracture reconstruction. Thus, careful selection of proper implants before surgery and close postoperative follow-up is needed for an optimal outcome.

Early Hypoglobus in Orbital Floor Reconstruction With Resorbable Implants

BACKGROUND

Among the variety of materials developed for facial bone surgery, resorbable implants are widely used in orbital wall reconstruction. There are many advantages in selecting resorbable implants, such as minimal foreign body reaction and adjustability within the damaged orbital floor. Resorbable implants are supposed to remain in place over 1 to 2 years to hold the structure of immature healing tissue surrounding the bony defects. However, some patients who have undergone orbital wall reconstruction surgery with resorbable implants suffer from early hypoglobus.

METHODS

This retrospective study was performed from January 2014 to August 2019 and follows 39 patients with unilateral pure orbital floor fractures. All orbital floor reconstruction was performed using resorbable implants via the transconjunctival approach. Exophthalmometer measurements and CT scans showing the degree of implant sagging were used to provide an index of hypoglobus.

RESULTS

Most patients showed hypoglobus over 3 to 4 months follow-up. The size of bony defect in the orbital floor showed positive correlation with follow-up exophthalmometer measurement and degree of implant sagging.

CONCLUSION

Orbital floor reconstructed with resorbable implant tends to lose load-bearing strength gradually, especially in large bony defects. Therefore, surgeons should be cautious about using resorbable implants for the maintenance of reconstructed orbital floor, especially in large bony defects.

Management of Pediatric Orbital Fractures

INTRODUCTION

Although uncommon in children, orbital fractures can be devastating to both vision and appearance. Due to the scarce information in the literature, the authors here present our experience and management with all pediatric orbital fracture patients.

MATERIAL AND METHODS

A 6-years retrospective study was conducted on pediatric patients presented with orbital wall fracture (OFx). All patients (n = 43) were grouped for comparison based on the treatment method. The cohorts were analyzed for demographics data, location of fracture, type of material used for reconstruction, complication rate and follow up length. Data was analyzed utilizing SPSS for χ2 test.

RESULTS

The majority of patients were male (86%) and the mean age of patients was 12.09 ± 4 years. Mean follow-up time was 237 ± 72 days. Most of Patients 31 (72%) underwent surgical intervention. A higher rate of complications was observed in the surgically treated group (32%) compared to the conservative group (8%) regardless to the defect size. Subgroup analysis of the surgery treated group revealed that large size defect had inferior outcome compared to small size defect.

CONCLUSION

The consequences of treatment on long-term growth and development must be a cornerstone when choosing the optimal therapeutic method. Conservative management should be considered first in the absence of significant clinical pathologies. In addition, when surgery is indicated the least invasive procedure should be applied. The use of autogenous bone graft is preferable over alloplastic materials, however, when there is insufficient bone quantity the use of alloplastic materials is not contraindicated for reconstruction.

Theoretical model of pediatric orbital trapdoor fractures and provisional personalized 3D printing-assisted surgical solution

Pediatric orbital trapdoor fractures are common in children and adolescents and usually require emergency surgical intervention. Herein, a personalized 3D printing-assisted approach to surgical treatment is proposed, serving to accurately and effectively repair pediatric orbital trapdoor fractures. We first investigated stress distribution in external force-induced orbital blowout fractures via numerical simulation, determining that maximum stresses on inferior and medial walls exceed those on superior and lateral walls and thus confer higher probability of fracture. We also examined 36 pediatric patients treated for orbital trapdoor fractures between 2014 and 2019 to verify our theoretical construct. Using 3D printing technique, we then created orbital models based on computed tomography (CT) studies of these patients. Absorbable implants were tailor-made, replicating those of 3D-printed models during surgical repairs of fractured orbital bones. As follow-up, we compared CT images and clinical parameters (extraocular movements, diplopia, enophthalmos) before and 12 months after operative procedures. There were only two patients with diplopia and six with enophthalmos >2 mm at 12 months, attesting to the efficacy of our novel 3D printing-assisted strategy.

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Numerical simulation is used to theoretically investigate the mechanism of external force-induced orbital blowout fractures.

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3D printing--assisted surgical treatment is proposed to effectively repair pediatric orbital trapdoor fractures.

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Clinical studies are performed by repairing fractured orbital bones via 3D printed customized absorbable implants.

Orbital wall restoration with primary bone fragments in complex orbital fractures: A preliminary study

BACKGROUND

We have reported orbital wall restoration surgery with primary orbital wall fragment in pure blowout fractures using a combination of transorbital and transnasal approach in pure blow out fractures. However, this method was thought to be difficult to use for complex orbital wall fractures, since the sharp screw tip that fixate the maxillary wall increases the risk of balloon ruptures. In this study, we reviewed 23 cases of complex orbital fractures that underwent orbital wall restoration surgery with primary orbital wall fragment and evaluated the result.

METHODS

A retrospective review was conducted of 23 patients with complex orbital fracture who underwent orbital restoration surgery with primary orbital wall fragments between 2012 and 2019. The patients underwent orbital wall restoration surgery with primary orbital wall fragment with temporary balloon support. The surgical results were evaluated by the Naugle scale and a comparison of preoperative and postoperative orbital volume ratio. Complex fracture type, type of screw used for fixation and complications such as balloon rupture were also investigated.

RESULTS

There were 23 patients with complex orbital fracture that used transnasal balloon technique for restoration. 17 cases had a successful outcome with no complications, three patients had postoperative balloon rupture, two patients had soft-tissue infection, and one patient had balloon malposition.

CONCLUSION

The orbital wall restoration technique with temporary balloon support can produce favorable results when done correctly even in complex orbital wall fracture. Seventeen cases had favorable results, six cases had postoperative complications thus additional procedure seems necessary to complement this method.

Biodegradable implants for orbital wall fracture reconstruction

BACKGROUND

Due to the different handling properties of unsintered hydroxyapatite particles/poly-L-lactic acid (uHA/PLLA) and polycaprolactone (PCL), we compared the surgical outcomes and the postoperative implantation accuracy between uHA/PLLA and PCL meshes in orbital fracture repair.<br/>.

METHODS

Patients undergoing orbital wall reconstruction with PCL and uHA/PLLA mesh, between 2017 and 2019, were investigated retrospectively. The anatomical accuracy of the implant in bony defect replacement and the functional outcomes such as diplopia, ocular motility, and enophthalmos were evaluated.<br/>.

RESULTS

No restriction of eye movement was reported in any patient (n=30 for each group), 6 months postoperatively. In the PCL group, no patient showed diplopia or enophthalmos, while the uHA/PLLA group showed two patients with diplopia and one with enophthalmos. Excellent anatomical accuracy of implants was observed in 27 and 22 patients of the PCL and uHA/PLLA groups, respectively. However, this study showed that there were neither any significant differences in the surgical outcomes like diplopia and enophthalmos nor any complications with the two well-known implants.<br/>.

CONCLUSION

PCL implants and uHA/PLLA implants are safe and have similar levels of complications and surgical outcomes in orbital wall reconstruction.

Orbital wall restoring surgery with primary orbital wall fragments in blowout fracture

Most orbital surgeons believe that it's difficult to restore the primary orbital wall to its previous position and that the orbital wall is so thin that cannot be firmly its primary position. Therefore, orbital wall fractures generally have been reconstructed by replacing the bony defect with a synthetic implant. Although synthetic implants have sufficient strength to maintain their shape and position in the orbital cavity, replacement surgery has some drawbacks due to the residual permanent implants. In previous studies, the author has reported an orbital wall restoring technique in which the primary orbital wall fragment was restored to its prior position through a combination of the transorbital and transantral approaches. Simple straight and curved elevators were introduced transnasally to restore the orbital wall and to maintain temporary extraorbital support in the maxillary and ethmoid sinus. A transconjunctival approach provided sufficient space for implant insertion, while the transnasal approach enabled restoration of the herniated soft tissue back into the orbit. Fracture defect was reduced by restoring the primary orbital wall fragment to its primary position, making it possible to use relatively small size implant, furthermore, extraorbital support from both sinuses decreased the incidence of implant displacement. The author could recreate a natural shape of the orbit with the patient's own orbital bone fragments with this dual approach and effectively restored the orbital volume and shape. This procedure has the advantages for retrieving the orbital contents and restoring the primary orbital wall to its prior position.

Orbital wall restoring surgery with resorbable mesh plate

BACKGROUND

Orbital resorbable mesh plates are adequate to use for isolated floor and medial wall fractures with an intact bony buttress, but are not recommended to use for large orbital wall fractures that need load bearing support. The author previously reported an orbital wall restoring surgery that restored the orbital floor to its prior position through the transnasal approach and maintained temporary extraorbital support with a balloon in the maxillary sinus. Extraorbital support could reduce the load applied on the orbital implants in orbital wall restoring surgery and the use of resorbable implants was considered appropriate for the author's orbital wall restoring technique.

METHODS

A retrospective review was conducted of 31 patients with pure unilateral orbital floor fractures between May 2014 and May 2018. The patients underwent transnasal restoration of the orbital floor through insertion of a resorbable mesh plate and maintenance of temporary balloon support. The surgical results were evaluated by the Hertel scale and a comparison of preoperative and postoperative orbital volume ratio (OVR) values.

RESULTS

The OVR decreased significantly, by an average of 6.01% (p< 0.05) and the preoperative and postoperative Hertel scale measurements decreased by an average of 0.34 mm with statistical significance (p< 0.05). No complications such as buckling or sagging of the implant occurred among the 31 patients.

CONCLUSION

The use of resorbable mesh plate in orbital floor restoration surgery is an effective and safe technique that can reduce implant deformation or complications deriving from the residual permanent implant.