Han Sang-Hyun, Hyun Seung-Jae, Jahng Tae-Ahn, Kim Ki-Jeong
Department of Neurosurgery, Spine Center, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Korean J Spine. 2015 Jun;12(2):60-7. doi: 10.14245/kjs.2015.12.2.60. Epub 2015 Jun 30.
This study aimed to investigate radiographic fusion rates at L4-5 and L5-S1 after single level posterior lumbar interbody fusion (PLIF) and evaluate the relationship between fusion rates and preoperative disc slope angle (DSA), lumbar lordosis (LL), segmental angle (SA), and pelvic parameters.
We conducted a retrospective review of patients who underwent single level PLIF at L4-5 or L5-S1 during May 2003-December 2012 at our institution. 73 patients were finally enrolled. Fusion was assessed by use of the Brantigan-Steffee classification, less than 2mm translation and less than 5° motion on the flexion-extension lateral radiographs. We analyzed the radiographic fusion rates, risk factors, and relationship of fusion rates with DSA, LL, SA, and pelvic parameters.
There were 59 patients (80.8%) in the L4-5 group and 14 (19.2%) in L5-S1 (average follow-up, 34 months). The radiographic fusion rates were 89.8% in the L4-5 group (53/59) and 42.9% in L5-S1 (6/14) (p<0.001).The preoperative DSA was significantly lesser in the L4-5 group than in the L5-S1 group (13.1±8.1° vs. 27.2±6.7°, p<0.001). The LL, SA, and pelvic parameters were not related with radiographic fusion rates in both groups. Risk factors for non-union were not identified between the two groups except for the surgery level (p<0.001).
The radiographic fusion rate at L5-S1 was less than half that at L4-5 after single level PLIF. This may be due to the anatomical and biomechanical differences between the two levels. More vigorous effort to achieve successful fusion at L5-S1 should be considered.
本研究旨在调查单节段腰椎后路椎间融合术（PLIF）后L4-5和L5-S1节段的影像学融合率，并评估融合率与术前椎间盘倾斜角（DSA）、腰椎前凸（LL）、节段角（SA）和骨盆参数之间的关系。
我们对2003年5月至2012年12月在我院接受L4-5或L5-S1单节段PLIF手术的患者进行了回顾性研究。最终纳入73例患者。通过Brantigan-Steffee分类、屈伸位侧位X线片上平移小于2mm和活动度小于5°来评估融合情况。我们分析了影像学融合率、危险因素以及融合率与DSA、LL、SA和骨盆参数之间的关系。
L4-5组有59例患者（80.8%），L5-S1组有14例患者（19.2%）（平均随访34个月）。L4-5组的影像学融合率为89.8%（53/59），L5-S1组为42.9%（6/14）（p<0.001）。L4-5组术前DSA明显小于L5-S1组（13.1±8.1°对27.2±6.7°，p<0.001）。两组的LL、SA和骨盆参数与影像学融合率均无相关性。除手术节段外，两组间未发现不融合的危险因素（p<0.001）。
单节段PLIF术后L5-S1的影像学融合率不到L4-5的一半。这可能是由于两个节段在解剖学和生物力学上的差异。应考虑采取更积极的措施以实现L5-S1的成功融合。
