Research progress on the biological modifications of implant materials in 3D printed intervertebral fusion cages

Anterior spine decompression and reconstruction with bone grafts and fusion is a routine spinal surgery. The intervertebral fusion cage can maintain intervertebral height and provide a bone graft window. Titanium fusion cages are the most widely used metal material in spinal clinical applications. However, there is a certain incidence of complications in clinical follow-ups, such as pseudoarticulation formation and implant displacement due to nonfusion of bone grafts in the cage. With the deepening research on metal materials, the properties of these materials have been developed from being biologically inert to having biological activity and biological functionalization, promoting adhesion, cell differentiation, and bone fusion. In addition, 3D printing, thin-film, active biological material, and 4D bioprinting technology are also being used in the biofunctionalization and intelligent advanced manufacturing processes of implant devices in the spine. This review focuses on the biofunctionalization of implant materials in 3D printed intervertebral fusion cages. The surface modifications of implant materials in metal endoscopy, material biocompatibility, and bioactive functionalizationare summarized. Furthermore, the prospects and challenges of the biofunctionalization of implant materials in spinal surgery are discussed.

Displacement of the full body of a dental implant into the sinus space without membrane perforation and subsequent osseointegration: a case report

An increasing number of studies have investigated the use of osteotome sinus floor elevation (OSFE) with simultaneous implant placement for maxillary sinus floor residual bone height (RBH) <4 mm. Many studies have reported good clinical results, but very few have reported complications related to this procedure. Here, the case of a 50-year-old female patient with an RBH in the left upper posterior region of 1–4 mm, who underwent OSFE with simultaneous placement of three Bicon short® implants, is described. One of the implants was found to be displaced during the second-stage surgery. The displaced implant was removed using piezosurgery, OSFE with simultaneous implant placement was repeated, and the missing tooth was reconstructed 6 months later. This case suggests that OSFE with simultaneous implant placement is feasible for severely atrophic maxillary sinus floor, but carries a risk of implant displacement.

Implants displaced into the maxillary sinus, an endoscopic approach - a report of two cases

Accidental implant displacement into the maxillary sinuses and accompanying complications are well documented in the literature. Two surgical approaches have been suggested to remove the displaced implants and to handle the related complications: an intraoral approach and the nasal endoscopy. The intraoral approach is preferred in cases of absence of local infection, ostium obstruction, and oroantral communication needing to be closed. The nasal approach, besides retrieval of displaced implants, allows the treatment of any associated pathology and reestablishment of the mucociliary clearance as well as the natural ventilation through the ostium. This article reports two clinical cases of implant displacement in the maxillary sinus treated with a nasal endoscopy through the middle meatal meatotomy. This article reports two clinical cases of implant displacement in the maxillary sinus treated with a nasal endoscopy through the middle meatal meatotomy. Implants accidentally displaced can be avoided by a proper exploration of the preoperative x-ray, selecting an appropriate treatment plan, and esteeming the surgical skills. The most appropriate approach to handle these complications is close cooperation between oral surgeons and otolaryngologists.

Dental implant displacement into the mandibular body: a case report

Posterior mandible region is considered a highly predicable place for primary stability during dental implant placement. Although, this region can present a significant decrease in bone density, which can lead to implant dislocation during insertion. The present case reports an unusual dislocation of dental implant in a 59 old healthy patient's mandible and a secure solution for this kind of complication. During the drilling, bone quality type IV was observed. In sequence, implant was abruptly inserted in the perforation site and dropped into the bone marrow. Panoramic radiograph showed the implant inside bone marrow, close to mandibular base. The implant was removed through the surgical site. The screw of the implant prosthesis transfer was used to reach the displaced implant. A second implant with the same dimensions as the first one, differing by the external hexagon, was inserted into the same implant site. Therefore, the authors strongly recommend the use of the presented technique prior to osteotomy on mandibular body, reserving the second in the impossibility of reaching the internal connection of the displaced implant.

Impact of Bone Augmentation of Facial Bone Defect around Osseointegrated Implant: A Three Dimensional Finite Element Analysis

(1) Background: When dental implants are placed at the esthetic zone, facial bone fenestration might be expected. This study aimed to evaluate the biomechanical effect of bone augmentation around implants with facial bone fenestration defects using the finite element method. (2) Methods: An anterior maxillary region model with facial concavity was constructed with a threaded implant inserted following the root direction, resulting in apical threads exposure to represent the fenestration model. Several bone coverage levels were simulated by gradually shifting the deepest concavity point buccally, mimicking bone augmentation surgeries with different bone fill results. Oblique forces were applied, and analysis was performed. (3) Results: Peak compressive stress magnitude and distribution varied according to the level of exposure and facial concavity depth. The fenestration model demonstrated a slightly lower peak peri-implant bone stress, smaller implant displacement, and smaller bone volume with strain levels above 200 µ strain. A gradual increase in compressive stress, implant displacement, and bone volume exhibited strain level above 200 µ strain was observed with the increased bone fill level of the facial bone fenestration. (4) Conclusions: Exposure of implants apical threads at the maxillary anterior region does not significantly affect the peri-implant stress and strain results. However, increasing the buccolingual width and eliminating the buccal concavity might increase the peri-implant bone volume exhibited favorable loading levels.

Replacement of an extensive chest wall defect in combination with the elimination of postoperative ventral hernia after combined treatment of breast cancer complicated by osteomyelitis of the sternum and ribs

Plastic replacement of osteochondral defect of the chest wall after surgical treatment of osteomyelitis of the sternum and ribs is a complex and topical issue in surgery. Often, an extensive post-resected defect of the sternum and ribs is combined with instability of the frame of the chest wall and thoracoabdominal hernia, which leads to physiological and socio-psychological maladaptation of the patient. The case of successful replacement of an extensive chest wall defect in combination with a ventral hernia in a patient after combined treatment of breast cancer complicated by osteomyelitis of the sternum and ribs is presented. TiNi- reinforcing rib prostheses and TiNi-mesh were used to create the frame of the chest wall and hernioplasty. 5-year follow-up did not reveal a recurrence of osteomyelitis and ventral hernia, implant displacement and instability of the frame of the chest wall. The method of reconstruction of an extensive thoracoabdominal defect using bioadaptive implants from TiNi is safe and effective in patients at the final stage of surgical treatment of osteomyelitis of the chest wall including in combination with ventral hernia. Thanks to the developed technology, an excellent functional result was achieved.

Cervical edema after anterior cervical fusion, a rare but potentially fatal complication: a case report

<p>Anterior approaches to the cervical spine can be performed for spine decompression and instrumentation in many pathologic conditions. Cervical spine surgeries complicate in 5.3% of cases, with anterior procedures representing 65% of them. Airway compromise requiring tracheostomy or reintubation is rare but may lead to potentially catastrophic complications. There are several causes for airway compromise, including post-operative cervical swelling or hematoma, pharyngeal edema, cerebrospinal fluid (CSF) leak, angioedema, and graft or implant displacement. We present a case of a 57-year-old male with chronic neck and left radicular pain. He was submitted to C5-C6 anterior cervical disc fusion that was complicated with airway compromise in the orthopedics ward. The patient required emergent reintubation for airway protection, wound exploration and intensive care. Hematoma is often the first diagnosis to consider in the immediate postoperative period. A low threshold for intubation should be maintained. After airway protection, it is essential to differentiate etiologies, to guide subsequent management.</p><p><strong> </strong></p>