Davis KW, Blankenbaker DG. ExpertDDX: Musculoskeletal, 2nd Edition. Elsevier; 2018;968 pp;3,100 ill; $299.99. Expert DDX: Musculoskeletal, 2nd Edition is the second book in the ExpertDDX series. The series addresses a challenge inherent to reference books of differential diagnoses. The authors, Kirkland W.