RESUMEN
Bone cement is used as a mortar for securing bone implants, as bone void fillers or as spacers in orthopaedic surgery. Antibiotic-loaded bone cements (ALBCs) have been used to prevent and treat prosthetic joint infections by providing a high antibiotic concentration around the implanted prosthesis. High antibiotic concentrations are, on the other hand, often associated with tissue toxicity. Controlling antibiotic release from ALBCS is key to achieving effective infection control and promoting prosthesis integration with the surrounding bone tissue. However, current ALBCs still need significant improvement in regulating antibiotic release. In this review, we first provide a brief introduction to prosthetic joint infections, and the background concepts of therapeutic efficacy and toxicity in antibiotics. We then review the current state of ALBCs and their release characteristics before focusing on the research and development in controlling the antibiotic release and osteo-conductivity/inductivity. We then conclude by a discussion on the need for better in vitro experiment designs such that the release results can be extrapolated to predict better the local antibiotic concentrations in vivo.
RESUMEN
PURPOSE: To determine the effect of the coinjection of bupivacaine with botulinum toxin type A on the degree of muscular paralysis. Enhancement of paralysis could allow a decreased dose of neurotoxin treatment, thus reducing the risk for neutralizing antibody formation. METHODS: Prospective, randomized, double-blind study. Sixteen consecutive patients undergoing treatment of glabellar furrows received botulinum toxin A reconstituted with bupivacaine 0.75% to one corrugator muscle and botulinum toxin A reconstituted with nonpreserved normal saline to the contralateral muscle. Patients were evaluated on days 0 (injection day), 3, 7, 30, 60, and 90. Patients also completed a questionnaire each visit regarding their assessment of paralysis, asymmetry, and adverse effects. RESULTS: At 1 week after botulinum toxin A injection, 68.8% of the patients showed greater weakness on the bupivacaine-reconstituted side as opposed to 25.0% of patients showing greater weakness on the saline-reconstituted side. At 1 and 3 months, there was no statistical difference in weakness between the saline and the bupivacaine sides. The survey revealed that 56% of the patients had greater pain on the saline side, 31% on the bupivacaine side, and equal pain in 13%. CONCLUSIONS: Reconstituting botulinum toxin A with bupivacaine is safe, does not limit efficacy, and does not reduce the degree or relative duration of muscular paralysis. Reconstituting botulinum toxin A with bupivacaine results in faster onset of paresis, possibly due to a synergistic effect of bupivacaine induced myotoxicity. Utilizing bupivacaine may result in less pain for patients.