Results of seven years' follow-up of Coflex interspinous process device in the treatment of degenerative lumber spine stenosis

ZHENG Xiao-qing; CHANG Yun-bing; GU Hong-lin; LIANG Guo-yan; ZHUANG Jian-xiong; YIN Dong; LIU Bin

doi:10.3969/j.issn.2095-252X.2018.02.003

Abstract：Objective To summarize the midterm and long-term ( > 7 years ) follow-up results of patients with adjacent segmental degeneration after the treatment of degenerative lumbar spinal stenosis with the Coflex interspinous process device. Methods One hundred patients with L4-5degenerative lumbar spine stenosis were treated with surgery from June 2007 to June 2010. All patients had been followed up for more than 7 years. Fifty patients were treated by spinal canal decompression, Coflex ( Coflex Group, 11 lost patients, 39 patients in the latest follow-up ). The mean age was ( 57.6 ± 5.9 ) years ( range: 48 - 70 years ). Fifty patients were treated by spinal canal decompression,intervertebral fusion and internal pedicle fixation ( Fusion Group, 7 lost patients, 43 patients in the latest follow-up ). The mean age was ( 59.0 ± 6.7 ) years ( range: 50 - 73 years ). The operation time, intraoperative blood loss, off-bed time, hospital stay were compared between the 2 groups. Japanese Orthopedic Association ( JOA ) scores, visual analogue scale ( VAS ) scores, Oswestry disability index ( ODI ) scores were compared between the 2 groups. The range of the increased intervertebral motion and the loss of intervertebral height of the adjacent segments ( L3-4and L5- S1) were measured preoperatively and at the latest follow-up. Adjacent segment degeneration of L3-4, L5- S1were assessed by Pfirrmann. Complications were also recorded. Results The average follow-up was ( 7.12 ± 1.1 ) years in Coflex Group and ( 7.31 ± 1.6 ) years in the Fusion Group. In the Coflex group, the operation time, intraoperative blood loss, off-bed time, hospital stay were ( 54.33 ± 12.17 ) min, ( 74.74 ± 23.33 ) ml, ( 2.30 ± 0.46 ) days, ( 5.61 ± 1.13 ) days respectively, and in the Fusion Group ( 99.48 ± 24.56 ) min, ( 184.10 ± 47.98 ) ml, ( 3.79 ± 0.76 ) days, ( 8.28 ± 0.68 ) days respectively. Coflex Group performed better than the Fusion Group with statistical differences ( P < 0.01 ). JOA, ODI, VAS ( Coflex Group ): ( 11.84 ± 2.45 ), ( 41.94 ± 3.26 ), ( 7.33 ± 1.08 ) preoperatively; ( 25.87 ± 2.06 ), ( 4.58 ± 1.77 ), ( 1.92 ± 0.62 ) at the latest follow-up. JOA, ODI, VAS ( Fusion Group ): ( 11.00 ± 2.01 ), ( 42.92 ± 2.10 ), ( 7.41 ± 0.93 ) preoperatively; ( 24.23 ± 3.27 ), ( 4.66 ± 1.45 ), ( 2.30 ± 0.97 ) at the latest follow-up. JOA, ODI, VAS were improved after the surgery in both groups with statistical differences ( P < 0.01 ). No statistical differences existed between the 2 groups ( P > 0.05 ). The range of lost intervertebral height of adjacent segments: ( 1.78 ± 0.70 ) mm ( L3-4), ( 1.48 ± 0.38 ) mm ( L5- S1) in the Coflex Group, ( 4.30 ± 0.87 ) mm ( L3-4), ( 2.69 ± 0.49 ) mm ( L5- S1) in the Fusion Group. At the latest follow-up, the intervertebral space height was reduced in both groups. Height lost was more obvious in the Fusion Group, with statistical significance ( P < 0.01 ). The range of increased intervertebral motion of adjacent segments: ( 3.05 ± 1.30 ) ° ( L3-4), ( 3.04 ± 1.24 ) ° ( L5- S1) in the Coflex Group; ( 4.03 ± 0.34 ) ° ( L3-4), ( 4.01 ± 0.33 ) ° ( L5- S1) in the Fusion Group. At the latest follow-up, the range of intervertebral motion of adjacent segments was increased in both groups. Range increase was more obvious in the Fusion Group, with statistical significance ( P < 0.01 ). At the latest follow-up, adjacent segment disc Pfirrmann grading progressed more obviously in the Fusion Group, with statistical differences between the 2 groups ( P < 0.05 ). Conclusions Coflex and fusion technology can achieve good clinical effects at midterm and long-term follow-up in the treatment of degenerative lumbar spine stenosis. Coflex has advantages of less bleeding, less invasive, quicker recovery. It also can maintain the intervertebral height and delay the disc degeneration. Long-term follow-up observation is needed.