Designing maxillofacial prosthesis for bone reconstruction: an overview

A cranio-maxillofacial region contains several bones and serves to protect and support the area, from the brain to the masticatory system. In this paper the clinical and research aspects of craniomaxillofacial biomaterials have been highlighted to serve as a guide into the wide world of their reconstructions. After a quick look into the anatomy, the review focuses on the causes of large bone defects in this region, and how they influence the designing process of the implant. Since it is a large area to unfold, only the maxillary, the mandible and the temporomandibular joints are highlighted. Understanding the biomechanics of mandible and temporomandibular joints is quite important, as it strongly influences the choice of the biomaterial. Thus, the latest techniques implemented to understand the biomechanics of the mandible are also highlighted. Via the finite element analysis, a simulation can help to identify the forces and the movements of the mandible and to predict the possible outcome of the implantation influencing the choice of the biomaterial.

Immunohistochemical analysis revealed the expression of bone morphogenetic proteins-4, 6, 7, and 9 in human induced membrane samples treated with the Masquelet technique

Background Induced membrane (IM) is the key component of Masquelet reconstruction surgery for the treatment of bone defects. IM is formed around the cement spacer and is known to secrete growth factors and osteoinductive factors. However, there is limited evidence available concerning the presence of osteoinductive factors in IM. This study aimed to investigate the existence of bone morphogenetic proteins (BMPs) in IM harvested from patients during the treatment of bone defects using the Masquelet technique. Methods This study involved six patients whose bone defects had been treated using the Masquelet technique. The affected sites were the femur (n = 3) and the tibia (n = 3). During the second-stage surgery, 1 cm2 pieces of IM were harvested. Histological sections of IM were immunostained with anti-BMP-4, 6, 7, and 9 antibodies. Human bone tissue served as the positive control. Results The presence of BMP-4, 6, 7, and 9 was observed in all IM samples. Further, immunolocalization of BMP-4, 6, 7, and 9 was observed in blood vessels and fibroblasts in all IM samples. Immunolocalization of BMP-4, 6, 7, and 9 was also observed in bone tissue within the IM in one sample, in which osteogenesis inside the IM was observed. Conclusions This study showed that osteoinductive factors BMP-4, 6, 7, and 9 were present in the IM harvested from patients, providing evidence indicating that the Masquelet technique effectively contributes to healing large bone defects. Therefore, it may be possible for surgeons to omit the addition of BMPs to bone grafts, given the endogenous secretion of BMPs from the IM.

Efficacy of Neuroendoscopic Treatment for Septated Chronic Subdural Hematoma

Objective: Neuroendoscopic treatment is an alternative therapeutic strategy for the treatment of septate chronic subdural hematoma (sCSDH). However, the safety and efficacy of this strategy remain controversial. We compared the clinical outcomes of neuroendoscopic treatment with those of standard (large bone flap) craniotomy for sCSDH reported in our center. Furthermore, the safety and efficacy of the neuroendoscopic treatment procedure for sCSDH were evaluated.Methods: We retrospectively collected the clinical data of 43 patients (37 men and six women) with sCSDH who underwent either neuroendoscopic treatment or standard (large bone flap) craniotomy, such as sex, age, smoking, drinking, medical history, use of antiplatelet drugs, postoperative complications, sCSDH recurrence, length of hospital stay, and postoperative hospital stay. We recorded the surgical procedures and the neurological function recovery prior to surgery and 6 months following the surgical treatment.Results: The enrolled patients were categorized into neuroendoscopic treatment (n = 23) and standard (large bone flap) craniotomy (n = 20) groups. There were no differences in sex, age, smoking, drinking, medical history, antiplatelet drug use, postoperative complications, and sCSDH recurrence between the two groups (p > 0.05). However, the patients in neuroendoscopic treatment group had a shorter length of total hospital stay and postoperative hospital stay as compared with the standard craniotomy group (total hospital stay: 5.26 ± 1.89 vs. 8.15 ± 1.04 days, p < 0.001; postoperative hospital stay: 4.47 ± 1.95 vs. 7.96 ± 0.97 days, p < 0.001). The imaging and Modified Rankin Scale at the 6-month follow-up were satisfactory, and no sCSDH recurrence was reported in the two groups.Conclusions: The findings of this study indicate that neuroendoscopic treatment is safe and effective for sCSDH; it is minimally invasive and could be clinically utilized.

In situ mineralized PLGA/zwitterionic hydrogel composite scaffolds enable high-efficiency rhBMP‑2 release for critical-sized bone healing

Seeking an osteoconductive and osteoinductive scaffold is highly desirable for functional restoration of large bone defects. Here, we report an in situ mineralized poly(lactic-co-glycolic acid)/poly[2-(methacryloyloxy)ethyl] dimethyl-(3-sulfopropyl)ammonium hydroxide hydrogel (PLGA/PSBMA) scaffolds...

Three Staged Revision Arthroplasty Using Structural Allograft in Chronic Periprosthetic Joint Infection Accompanied by Fracture: A Case Report

Revision arthroplasty for chronic periprosthetic joint infection is complex and determined by many variables. Generally, two-staged revision arthroplasty is the standard treatment for the management of chronic periprosthetic joint infection. However, it is difficult to resolve chronic infection accompanied by large bone deficiency due to pathologic fracture. I report a case of successful three-staged revision arthroplasty using frozen structural allograft in chronic periprosthetic knee joint infection accompanied by extensive bone defect due to fracture.

Evaluation of Human Bone Marrow Mesenchymal Stromal Cell (MSC) Functions on a Biomorphic Rattan-Wood-Derived Scaffold: A Comparison between Cultured and Uncultured MSCs

The reconstruction of large bone defects requires the use of biocompatible osteoconductive scaffolds. These scaffolds are often loaded with the patient’s own bone marrow (BM) cells to facilitate osteoinductivity and biological potency. Scaffolds that are naturally sourced and fabricated through biomorphic transitions of rattan wood (B-HA scaffolds) offer a unique advantage of higher mechanical strength and bioactivity. In this study, we investigated the ability of a biomorphic B-HA scaffold (B-HA) to support the attachment, survival and gene expression profile of human uncultured BM-derived mesenchymal stromal cells (BMSCs, n = 6) and culture expanded MSCs (cMSCs, n = 7) in comparison to a sintered, porous HA scaffold (S-HA). B-HA scaffolds supported BMSC attachment (average 98%) and their survival up to 4 weeks in culture. Flow cytometry confirmed the phenotype of cMSCs on the scaffolds. Gene expression indicated clear segregation between cMSCs and BMSCs with MSC osteogenesis- and adipogenesis-related genes including RUNX2, PPARγ, ALP and FABP4 being higher expressed in BMSCs. These data indicated a unique transcriptional signature of BMSCs that was distinct from that of cMSCs regardless of the type of scaffold or time in culture. There was no statistical difference in the expression of osteogenic genes in BMSCs or cMSCs in B-HA compared to S-HA. VEGF release from cMSCs co-cultured with human endothelial cells (n = 4) on B-HA scaffolds suggested significantly higher supernatant concentration with endothelial cells on day 14. This indicated a potential mechanism for providing vasculature to the repair area when such scaffolds are used for treating large bone defects.

Remained Large Bone Fragment of Bony Bankart Lesion in Shoulders With a Subcritical Glenoid Defect at Recurrent Anterior Instability

Background: A preoperative glenoid defect of 13.5% or larger is recognized as a subcritical glenoid defect at arthroscopic Bankart repair (ABR) for collision/contact athletes or military personnel. Purpose: To clarify the prevalence and size of remaining bone fragments in shoulders with a subcritical glenoid defect at recurrent anterior instability and to investigate the influence on postoperative recurrence after ABR for younger competitive athletes. Study Design: Cohort study; Level of evidence, 4. Methods: The study included 96 shoulders with recurrent instability that underwent ABR between July 2011 and March 2018 for shoulders with a subcritical glenoid defect. The patients were divided into 2 groups according to the glenoid defect size (13.5%-<20%, medium; ≥20%, large). The bone fragment size in each defect group was retrospectively investigated and classified into 4 groups (no, 0%; small, >0%-<5%; medium, 5%-<10%; large, ≥10%). The postoperative recurrence rate for each combination of glenoid defect size and bone fragment size was investigated for competitive athletes aged <30 years. The fragments, when present, were repaired to the glenoid. Results: The glenoid defect size was 13.5%-<20% in 60 shoulders (medium defect group) and ≥20% in 36 shoulders (large defect group). The mean bone fragment size was 6.7% ± 5.1% and 8.9% ± 4.9%, respectively ( P = .042). In the medium defect group, there were 15 shoulders (25%) without a bone fragment, 6 shoulders (10%) with a small fragment, 23 shoulders (38.3%) with a medium fragment, and 16 shoulders (26.7%) with a large fragment. In the large defect group, the respective numbers were 2 shoulders (5.6%), 6 shoulders (16.7%), 14 shoulders (38.9%), and 14 shoulders (38.9%). A medium or large bone fragment was more common in the large defect group ( P = .252). Among 64 younger competitive athletes who underwent ABR with a minimum of 2 years of follow-up, postoperative recurrence was recognized in 7 of 38 (18.4%) athletes in the medium defect group, but it was not recognized in any of the 26 athletes in the large defect group ( P = .036). Postoperative recurrence was recognized in 4 of 12 (33.3%) athletes with a small fragment or no fragment and in 3 of 52 (5.8%) athletes with a medium or large fragment ( P = .019). Conclusion: A larger bone fragment frequently remained in shoulders with a subcritical glenoid defect at recurrent instability. The postoperative recurrence rate after ABR for younger competitive athletes was low when a remaining larger bone fragment was repaired.