by Elizabeth Hofheinz, M.P.H., M.Ed. While spinal anesthesia confers benefits when administered during primary total hip arthroplasty (THA) and total knee arthroplasty (TKA), say the authors of a new Mayo Clinic study, the long-acting local anesthetics result in a “slow” and “unpredictable” return of lower-extremity motor function. Their double-blinded, randomized clinical trial, “More Predictable Return …