Treatment of orbital blowout fracture using porous polyethylene with embedded titanium

Discovery of CTSK+ Periosteal Stem Cells Mediating Bone Repair in Orbital Reconstruction

Purpose

The purpose of this study was to explore the role of cathepsin K positive (CTSK+) periosteal stem cells (PSCs) in orbital bone repair and to clarify the source of endogenous stem cells for orbital bone self-repair.

Methods

Periosteum samples obtained by clinical orbital bone repair surgery were analyzed, after which immunofluorescence and immunohistochemical staining were used to detect the content of bone marrow-derived cells and CTSK+ PSCs in periosteum as well as the mobilization of PSCs. CTSK+ PSCs were characterized by flow cytometry. Transcriptome sequencing was used to compare the transcriptomic characteristics of CTSK+ PSCs and bone marrow mesenchymal stem cells (BMSCs).

Results

The orbital periosteum contained CTSK+CD200+ cell lineage, including CD200+CD105- PSCs and CD200+CD105+ progenitor cells. CTSK and osteocalcin (OCN) colocalized in the inner layer of the orbital periosteum, suggesting the osteogenic differentiation potential of CTSK+ PSCs. CTSK expression was much higher in periosteum after mobilization. Immunofluorescence showed low amounts of scattered CD31+ and CD45+ cells in the orbital periosteum. The stem cell characteristics of CTSK+ PSCs were verified by multidirectional differentiation. Flow cytometry found CD200+CD105- CTSK+ PSCs and CD200variantCD105+ progenitor cells. Transcriptome sequencing of CTSK+ PSCs and BMSCs found 3613 differential genes with significant differences. Gene Ontology (GO) analysis showed the differences between the two types of stem cells, revealing that PSCs were more suitable for intramembranous osteogenesis.

Conclusions

CTSK+ PSCs may be endogenous stem cells for orbital bone repair. They are mobilized after orbital fracture and have unique features suitable for intramembranous osteogenesis, completely different from BMSCs.

Surgical repair of large orbital floor and medial wall fractures with destruction of the inferomedial strut: Initial experience with a combined endoscopy navigation technique

The application of navigation and endoscope is an area of intense interest in the surgical repair of orbital fractures. This study explored the advantages of a combined endoscopy navigation technique (ENT) for repairing large orbital floor and medial wall fractures (OFMWFs) with destruction of the inferomedial strut (IMS). Fifty-two consecutive patients with large OFMWFs with the destruction of the IMS underwent ENT-assisted surgical repair from January 2013 to February 2016. Patient demographics, causes of injury, clinical features, imaging data, and follow-up information (diplopia, ocular dysmotility, enophthalmos, infraorbital hypoesthesia, and other conditions) were collected and analyzed. Orbital volumes and implant positions were also evaluated. The median follow-up duration was 21 (range, 16-29) months. At the end of the follow-up visits, orbital reconstruction was demonstrated by orbital computed tomography. Of the 30 patients with diplopia within the 30-degree visual field of gaze, 27 (90%) reached diplopia remission. Of 40 patients, 34 (85%) achieved complete elimination of ocular dysmotility. Of 47 patients with enophthalmos of >2 mm, 43 (91%) acquired good symmetry with a mean improvement of 3.00 ± 1.00 mm. Of 33 patients, 27 (82%) recovered from infraorbital hypoesthesia. The postoperative orbital volumes of the two sides showed no significant differences (p = 0.087, paired t-test). Early surgical repair showed better outcomes of diplopia, ocular motility, and enophthalmos than late repair (p = 0.001, p = 0.007, and p = 0.000, generalized estimated equations). No patient developed surgery-related complications of visual acuity compromise, strabismus, ectropion, entropion, or lacrimal canaliculus injuries. ENT-assisted surgery appears to be safe, precise, and effective for the repair of large OFMWFs with destruction of the IMS.

Analysis of the effect of repair materials for orbital blowout fracture on complications

AIM

To investigate the effect of repair materials for orbital blowout fractures on the occurrence of postoperative complications.

METHODS

The clinical data and follow-up data of 54 subjects with orbital blowout fractures were retrospectively analyzed. The study was divided into three groups according to the used repair materials: titanium mesh (16 cases), Medpor (12 cases), and Medpor titanium mesh (26 cases). All test data were analyzed using the SPSS version 23.0 statistical software. The mean age and duration of disease between the groups were compared through one-way analysis of variance. The Chi-square (χ ²) test was used to compare the number of males and females, different fracture types, and different surgical approaches among groups. The χ ² test was used to compare the frequencies for complications in each group.

RESULTS

The baseline characteristics of age and gender in each group were matched (F=1.763, P=0.172; χ ²=0.026, P=0.987). In addition, there was no difference in the type of fracture and surgical approach (χ ²=0.460, P=0.977; χ ²=0.691, P=0.952), or the incidence of complications (χ ²=0.081, P=0.960) between the three groups.

CONCLUSION

Although there is no difference in effect of various repair materials on the incidence of complications, the effect of repair materials on postoperative complications of orbital blowout fractures should not be ignored.