Reporting of anaesthesia and pain management in preclinical large animal models of articular cartilage repair - A long way to go

Animal models continue to be used to investigate cartilage repair strategies. Adequate anaesthesia and pain management are essential in order to guarantee acceptable animal welfare as well as reproducible experimental results. This systematic review evaluates reporting of anaesthesia and pain management in surgical large animal models (horse, pig, dog, goat and sheep) of (osteo)chondral repair. Manuscripts published between 2015 and 2020 were included after a comprehensive search strategy. Data were evaluated using descriptive statistics and qualitative review. Out of 223 eligible studies, 220 studies contained incomplete information on anaesthetic and pain management. Pre-, intra- and post-operative analgesia were not mentioned in 68%, 94%, and 64% of manuscripts respectively. A total of 176 studies reported that animals underwent general anaesthesia during surgery. Surprisingly, 30% of these articles did not provide any detail on anaesthetic management, while 37% reported using inhalant, hypnotic or sedative drugs only, without mention of analgesics. Pain monitoring was not reported in 87% of manuscripts. The vast majority of preclinical large animal studies on cartilage repair did not meet veterinary clinical standards for anaesthesia and analgesia, and failed to report according to the ARRIVE international guidelines. In light of serious welfare, ethical and translational validity concerns, improvement is urgently needed.