Phyllis Thomas (plaintiff) underwent spinal surgery to correct neurological symptoms. Dr. Albert Metz (defendant) performed the surgery. Thomas later developed other neurological symptoms, which she attributed to the surgery. Thomas sued Metz for malpractice in operating on Thomas without medical necessity. Before trial, Metz's two neurological experts read Metz's pretrial deposition, in which Metz defended the surgery's necessity. At trial, both experts testified the surgery was necessary, an opinion the experts said they based on their review of hospital records and pretrial depositions. Thomas's lawyer thoroughly cross examined both experts. The jury returned its verdict for Metz. On appeal, Thomas argued that the trial judge: (1) improperly refused to require the experts to disclose the sources on which they based their opinions, and (2) improperly admitted expert testimony formed in part on statements Metz made in his deposition.