Review Question - QID 218154

A 42-year-old patient is being seen in your clinic with a chief complaint of right knee pain. His radiographs are available for review in Figure A. The patient is a competitive cyclist and medical school biochemistry professor, and he is adamant that he does not want knee surgery, as his racing season is set to begin within the next few months. The patient brings with him multiple studies that note that antagonism of the interleukin-1 receptor (IL-1r) can lead to reductions in knee pain. Which of the following orthobiologic substances has been shown to have the highest concentration of IL-1 receptor antagonist?