Comparison of the Unilateral and the Bilateral Pedicle Screw Fixation without Using an Interbody Cage: Randomized Clinical Trial

BACKGROUND: Lumbar spine instability is one of the main causes of low back pain and has become more prevalent in recent years. Bilateral pedicle screw fixation is used to perform posterior lumbar stabilization, which is complemented by the installation of an interbody cage. AIM: The aim of the study was evaluating of the results of unilateral and bilateral pedicle screw fixation without using of an interbody cage. METHODS: A prospective randomized study of 96 patients was carried out. Forty-seven patients were assigned to the group of the unilateral pedicle screw fixation versus 49 patients were moved to the group of the bilateral pedicle screw fixation of the lumbar spine. Of the 96 patients, 80 patients eventually were included in the study. However, seven patients in the first group and nine patients were lost to follow-up. Surgery timing, blood loss volume, clinical outcomes (scores on the Oswestry disability index [ODI], EQ-5D and visual analogue scale [VAS]) were evaluated in 6–12 months after surgical treatment. All the patients included in this study underwent functional and control computed tomography in 12 months after surgery. RESULTS: Both groups showed a significant improvement in VAS, EQ-5D, and ODI in 1 year after surgical treatment. The two groups significantly differed in the surgery timing (unilateral – 90.2 min; and bilateral – 129.4 min) and blood loss volume (unilateral – 152.7 ml; and bilateral – 230.1 ml), p < 0.05. CONCLUSIONS: Unilateral and bilateral pedicle screw fixation showed similar clinical results, while results in both types of fixation differed in slight manner. However, the duration of surgical treatment and intraoperative blood loss volume proved to be lower for the unilateral fixation group, which indicates that the use of the unilateral fixation can be the choice of performing posterior stabilization at a single-level instability of the spine without using an interbody cage.

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The influence of bilateral pedicle screw fixation on vibration response of the disc degenerated human lumbar spine: A finite element stress analysis

Technology and Health Care ◽

10.3233/thc-181273 ◽

2019 ◽

Vol 27 (4) ◽

pp. 441-450

Author(s):

Wei Fan ◽

Li-Xin Guo

Keyword(s):

Finite Element ◽

Lumbar Spine ◽

Stress Analysis ◽

Pedicle Screw ◽

Screw Fixation ◽

Pedicle Screw Fixation ◽

Vibration Response ◽

Finite Element Stress Analysis ◽

Human Lumbar Spine ◽

Bilateral Pedicle Screw

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In vivo dynamic motion characteristics of the lower lumbar spine: L4–5 lumbar degenerative disc diseases undergoing unilateral or bilateral pedicle screw fixation combined with TLIF

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-019-1198-6 ◽

2019 ◽

Vol 14 (1) ◽

Cited By ~ 1

Author(s):

Tao Nie ◽

De-jian Chen ◽

Benyu Tang ◽

Quanwei Song ◽

Xuqiang Liu ◽

...

Keyword(s):

Lumbar Spine ◽

Pedicle Screw ◽

Screw Fixation ◽

Pedicle Screw Fixation ◽

Dynamic Motion ◽

Lower Lumbar Spine ◽

Motion Characteristics ◽

Bilateral Pedicle Screw ◽

Lower Lumbar

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Biomechanical effect of cage position combined with bilateral pedicle screw fixation in the osteoporotic lumbar spine of oblique lumbar interbody fusion: a finite element analysis

10.21203/rs.3.rs-252095/v1 ◽

2021 ◽

Author(s):

Yichuan Qin ◽

Bin Zhao ◽

Jie Yuan ◽

Chaojian Xu ◽

Junqiang Su ◽

...

Keyword(s):

Finite Element ◽

Lumbar Spine ◽

Pedicle Screw ◽

Interbody Fusion ◽

Screw Fixation ◽

Pedicle Screw Fixation ◽

Lumbar Interbody Fusion ◽

Cage Subsidence ◽

Oblique Lumbar Interbody Fusion ◽

Bilateral Pedicle Screw

Abstract Background: The influence of cage position on postoperative cage subsidence has been paid increasing attention. The best cage position in oblique lumbar interbody fusion (OLIF) is still unclear. This study aimed to evaluate the biomechanical effects of different cage positions with stand-alone (SA) methods and bilateral pedicle screw fixation (BPSF) in the osteoporotic lumbar spine after OLIF.Methods: A finite element (FE) model of an intact L3-L5 lumbar spine was constructed. After validation, an osteoporosis model (OP) was constructed by assigning osteoporotic material properties. SA models (SA1, SA2, SA3) and BPSF models (BPSF1, BPSF2, BPSF3) in which a cage was placed in the anterior, middle and posterior third of the L5 superior endplate (SEP) were constructed at the L4-L5 segment of the OP. The L4-L5 range of motion (ROM), the stress of the L5 SEP, the stress of the cage and the stress of fixation were compared among the different models.Results: According to the degree of ROM of L4-L5, the stress of the L5 SEP and the stress of the cage for most physiological motions, the SA and BPSF models were ranked as follows: SA2＜SA1＜SA3, BPSF2＜BPSF1＜BPSF3. In BPSF2, the stress of fixation was minimal in most motions. At the same cage position, the ROM of L4-L5, the stress of the L5 SEP and the stress of the cage in the BPSF models were significantly reduced compared with those in SA models; compared with SA2, BPSF2 had a maximum reduction of 83.24%, 70.71% and 73.52% in these parameters, respectively.Conclusions: Placing the cage in the middle third of the L5 SEP for OLIF could reduce the maximum stresses of the L5 SEP, the cage and the fixation, which may reduce the risk of postoperative cage subsidence, endplate collapse and fixation fracture in the osteoporotic lumbar spine. Compared with SA OLIF, BPSF could provide sufficient stability for the surgical segment and may reduce the incidence of the aforementioned complications.

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