Modified methods of arytenoid adduction (AA) have been reported to keep the cricothyroid (CT) joint intact. However, postoperative laryngeal oedema and long-term vocal function have not been compared with those after AA with CT joint separation. We refined AA to combine it with nerve-muscle pedicle (NMP) flap transfer for preservation of the CT joint. Eight patients with unilateral laryngeal paralysis underwent the procedure (Group 1). Postoperative oedema at membranous vocal fold (MVF), arytenoid mound (AM) and pyriform sinus (PS) was assessed using a 4-point ordinal scale: none (0) to severe (3). Laryngeal oedema in Group 1 was compared with that of 19 patients who had AA with CT joint separation (Group 2). Maximum phonation time (MPT), jitter and voice handicap index-10 (VHI-10) were measured before surgery and one year postoperatively. Vocal function in Group 1 was compared with 58 patients who underwent AA + NMP flap transfer with CT joint separation (Group 3). The degree of oedema from postoperative days 1 to 6 in Group 1 was relatively invariable: 1.2~1.6 at MVF, 1.3~1.7 at AM, and 1.4~1.7 at PS. The scores at 3 and 4 days postoperatively at MVF and PS in Group 1 were significantly lower than in Group 2 (P = 0.0032 and 0.0317 at day 3, and 0.0224 and 0.0182, at day 4, respectively). The degree of oedema at day 3 at AM in Group 1 was significantly less than in Group 2 (P = 0.0260). One year after surgery, there were no significant differences in MPT, jitter and VHI-10 between Groups 1 and 3 (P = 0.660, 0.111 and 0.556, respectively). Preservation of the CT joint might be beneficial in reducing the maximum degree of laryngeal oedema after AA.