OBJECTIVETo evaluate the clinical and radiologic outcomes of the Hybrid surgery (cervical artificial disc replacement combined with anterior cervical discectomy and fusion (ACDF)) and the effective of the adjacent segment.

METHODSBetween December 2007 to June 2010, 34 patients underwent 2-level cervical disc surgery. There were 17 patients underwent Hybrid surgery (Hybrid group), 17 patients underwent 2-level ACDF (ACDF group). Japanese orthopaedic association (JOA), neck disability index (NDI), and Odom's standards were evaluated. Dynamic flexion and extension lateral cervical radiographs were obtained in the standing position before surgery and at routine postoperative intervals of 1, 3, 6 months.

RESULTSBoth of the two groups had significantly improvement than preoperative in JOA (t = -8.790 - -5.803, P < 0.05) and NDI scores (t = 10.717 - 13.514, P < 0.05), but no significantly difference between the two groups (P > 0.05). Both of the two groups had significantly decreased in the mean C(2-7) range of motion (ROM). The Hybrid group decreased from 46° ± 11° preoperative to 41° ± 8° at the 6 mouths after surgery (t = 3.170, P < 0.05). The ACDF group decreased from 45° ± 13° preoperative to 38° ± 15° at the 6 mouths after surgery (t = 6.709, P < 0.05). But there were no significantly difference between the two groups (P > 0.05). In the Hybrid group, both the superior adjacent segment ROM and the inferior adjacent segment ROM were decreased in the follow-up, there had significantly difference at the 1 and 3 months after surgery (superior adjacent segment: t = 5.622 and 4.032, P < 0.05; inferior adjacent segment: t = 2.879 and 2.207, P < 0.05), but no significantly difference after 6 months (P > 0.05). In the ACDF group, the ROM of the inferior adjacent segment was significantly increased at 3 and 6 months after surgery (t = -7.038 and -13.540, P < 0.05), the ROM of the superior adjacent segment was significantly increased at 6 months after surgery (t = -2.453, P < 0.05).

CONCLUSIONSHybrid surgery has excellent clinical results and decreases the ROM of the adjacent segment in the following 6 months, meanwhile 2-level ACDF increases the ROM of the adjacent segment. The long-term clinical outcomes of the Hybrid surgery need more study.