Expert’s comment concerning Grand Rounds case entitled “Paget’s disease of the lumbar spine: decompressive surgery following 17 years of bisphosphonate treatment” by A. Hofmann, S. Opitz, C. E. Heyde, N. H. von der Höh (Eur Spine J; 2018. https://doi.org/10.1007/s00586-018-5751-5)