Intra-articular adjuvant analgesics following knee arthroscopy: comparison between single and double dose dexmedetomidine and ropivacaine: a multicenter prospective double-blind trial - Panigrahi, R; Roy, R; Mahapatra, A K; Prasad, A; Priyadarshi, A; Palo, N (Orthop Surg, 2015)