Detection of Local Tissue Reactions after Anti-GnRF Injection in Male Pigs Assessed Using Magnetic Resonance Imaging

This study aimed at evaluating the local tissue reaction of an anti-GnRF product, which is used for the so called “immunocastration” in male pigs. A total of 34 pigs were injected two times (including a booster injection) with an anti-GnRF product. Injection was performed using the prescribed safety vaccinator. Injection sites were evaluated three times post injection using magnetic resonance imaging. Two examinations were performed after the first injection and one after the booster. The local tissue reaction was evaluated three-dimensionally by semi-automatic analyses, by linear measurements of injection depth and length, and by scoring the kind of tissue affected. Results showed a long-lasting reaction in affected muscle tissue. Therefore, needle length should be discussed, and an evaluation of the injection site after slaughter should be performed include behavioural scorings post injection to evaluate the impact on animal well-being and carcass quality.

Review of the local tissue reaction to metallic spinal implant debris: Ions and nanoparticles

Biologic reactivity to implant debris is the primary determinant of long-term clinical performance. The metallic implants placed in human bodies can exhibit electrochemical or mechanical corrosion that yields in the liberation of metallic products. Such implants-derived metal wear products can be present in the form of metal ions and particulate metal debris with still unknown effects on human health. In situ generation of metallic wear particles, corrosion products and in vivo trace metal ions release from metal and metallic alloys implanted into the body in spine surgery is becoming a major cause for concern regarding the health and safety of patients. In vivo clinical studies addressing the adverse local tissue reaction effects of metallic wear products on surrounding soft tissues and bodily fluids are less numerous. Although numerous studies have focused on the clinical significance of corrosion and wear of hip and knee replacements, research involving spine instrumentation is not well documented. This review explores how migration of metallic wear nanoparticles and trace metal ions in the area of metallic spinal implants influences the surrounding tissues and bodily fluids, and what the clinical consequences of this process may be.

Metal-on-metal total hip arthroplasty: does increasing modularity affect clinical outcome?

Background: Modularity of metal-on-metal (MoM) implants has come under scrutiny due to concerns regarding additional sources of metal debris. This study is a retrieval analysis of implants from the same manufacturer with the same MoM bearing surface. The difference between the implants was presence or absence of modular junctions. Methods: This is a retrospective study of 31 retrieved implants from 31 patients who received a Conserve Wright Medical MoM hip prosthesis. The 31 implants consisted of 16 resurfacings and 15 implants with modular junctions; 4 conventional THAs and 11 modular-neck THAs. Results: 43% of pre-revision MRI scans performed on resurfacing implants and 91% performed on the modular implants illustrated evidence of an adverse local tissue reaction. There was no difference in pre-revision blood metal ion levels or bearing surface wear between the resurfacings and modular implants. The neck-head tapers of the modular group showed low levels of material loss. However, the neck-stem tapers showed increased severity of corrosion and material loss Conclusions: The modular implants had an increased incidence of adverse local tissue reaction. This could be related to the presence of modular junctions, particular the neck-stem junction which showed increased susceptibly to corrosion