Comparison of posterolateral fusion with and without additional posterior lumbar interbody fusion for degenerative lumbar spondylolisthesis.
ABSTRACT The surgical approach that should be used for degenerative spondylolisthesis (DS) is a controversial issue. Decompression and posterolateral fusion (PLF) with or without lumbar interbody fusion is widely used. Many studies have compared the outcomes of these 2 approaches, but the appropriate indications for these approaches are still unclear. The authors retrospectively studied the effects of posterior lumbar interbody fusion (PLIF) after PLF for the treatment of DS.
Forty patients who underwent single level decompression and posterior instrumentation for DS at L4-5 and were followed for at least 2 years were retrospectively studied. The patients were divided into 4 groups: the stable PLF group (S-PLF, n=13); the stable PLF with additional PLIF group (S-PLIF, n=11); the unstable PLF group (U-PLF, n=8); and the unstable PLF with additional PLIF group (U-PLIF, n=8). Clinical and radiographic comparisons were carried out between the S-PLF and S-PLIF groups, and between the U-PLF and U-PLIF groups.
Clinical assessments, using the improvements of the Oswestry Disability Index (ODI) and the Visual Analog Scale (VAS), were statistically significantly different between the 2 unstable groups (DeltaU-PLF <DeltaU-PLIF, P(ODI)=0.032, P(VAS)=0.004, respectively). On radiologic assessment, the slip angle increment was significantly different between the 2 stable groups (DeltaS-PLF>DeltaS-PLIF, P=0.029), and the disc height increment was significantly different between the 2 stable groups (DeltaS-PLF<DeltaS-PLIF, P=0.043) and between the 2 unstable groups (DeltaU-PLF<DeltaU-PLIF, P=0.042).
This study suggests that preoperative segmental instability may be a criterion determining whether an additional PLIF would be beneficial in the treatment of lumbar DS.
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ABSTRACT: Retrospective radiographic evaluation of the sagittal alignment of the lumbar spine in patients undergoing short-segment instrumented posterior lumbar interbody fusion with cage systems of different shape. To determine whether rectangular and wedge-shaped cages have a different influence on the sagittal alignment of the lumbar spine in patients undergoing short-segment instrumented posterior lumbar interbody fusion. Previous studies of sagittal alignment after posterior lumbar interbody fusion have focused on the impact of intraoperative patient, hip, and knee positioning, as well as instrumentation characteristics on sagittal posture. The influence of the cage shape on indexes of total and segmental sagittal alignment of the lumbar spine is yet unknown. Forty-two patients having undergone instrumented short-segment posterior lumbar interbody fusion were reviewed retrospectively. Twenty-two patients (12 women and 10 men, 38-78 years of age) had posterior lumbar interbody fusion with rectangular cages. The fused segments were: 4 at L3-L4, 16 at L4-L5, 11 at L5-S1. Thirteen patients had single- and nine patients double-level fusion. Twenty patients (8 women and 12 men, 34-81 years of age) had posterior lumbar interbody fusion with wedge-shaped cages. The fused segments were: 4 at L3-L4, 15 at L4-L5, 11 at L5-S1. Ten patients had single- and 10 patients double-level fusion. Cages were packed with cancellous bone from the posterior iliac crest and/or bone fragments harvested by laminectomy. All patients had additional pedicle screw fixation. Pre- and postoperative standing lateral radiographs were assessed for segmental and lumbar lordosis as well lumbar and sacral tilt. Data were analyzed with repeated measures analysis of variance. RESULTS The mean follow-up period was 18 months with a minimum follow-up period of 14 months. Mean segmental lordosis of the fused segments showed significant changes between the two implant groups (P < 0.05). Segmental lordosis decreased in the rectangular cage group from 10 degrees to 2 degrees at L3-L4, from 10 degrees to 5 degrees at L4-L5, and from 9 degrees before to 6 degrees after fusion surgery at L5-S1. In the wedge-shaped cage group, segmental lordosis increased from 4 degrees to 7 degrees at L3-L4, from 2 degrees to 8 degrees at L4-L5, and from 9 degrees to 17 degrees at L5-S1. Analysis of changes in lumbar lordosis and lumbar and sacral tilt did not show significant differences though opposite trends: lumbar lordosis decreased from 55 degrees to 48 degrees in the rectangular cage group and increased from 45 degrees to 53 degrees in the wedge-shaped cage group. Lumbar tilt measured 98 degrees before and 102 degrees after surgery in the rectangular cage group and 97 degrees before and 94 degrees after surgery. Sacral tilt measured 44 degrees before and 40 degrees after surgery in the rectangular cage group and measured 42 degrees before and 45 degrees after surgery in the wedge-shaped cage group. The cage geometry has a significant impact on the alignment of the lumbar spine after instrumented posterior lumbar interbody fusion. With rectangular cages, lumbar lordosis and segmental lordosis of the segments fused decrease; sagittal balance is maintained by compensatory changes of the sacral tilt. Wedge-shaped cages significantly increase segmental lordosis, enhance lumbar lordosis, and therefore should be preferred for restoring sagittal alignment in instrumented posterior lumbar interbody fusion procedures.Spine 09/2003; 28(15):1693-9. · 2.16 Impact Factor
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ABSTRACT: One hundred, twenty-four patients undergoing lumbar or lumbosacral fusion for degenerative conditions were entered into a prospective study. The patients were randomly assigned to one of three treatment groups. Group I underwent posterolateral fusion using autogenous bone graft. Group II had autogenous posterolateral fusions supplemented by a semi-rigid pedicle screw/plate fixation system (Luque II; Danek Medical, Memphis, Tennessee). Group III patients underwent posterolateral autogenous fusion with a rigid pedicle screw/rod fixation system (Texas Scottish Rite Hospital [TSRH]-Danek Medical, Memphis, Tennessee). All the patients were operated on by the same surgeon, identical bone grafting technique was used in all, and all were treated in an identical fashion postoperatively. Fusion status was determined from the anteroposterior, oblique, and flexion-extension radiographs obtained at 1 year. Clinical results were rated as excellent if the patients were pain-free and had returned to work; good if the patients had mild backache requiring non-narcotic analgesics and had returned to work; fair if continuing back pain prevented a return to work; or poor if the pain was worse than that which the patient experienced preoperatively or the patient required revision surgery. Nine patients who were originally assigned to Group II or Group III were placed in Group I intraoperatively. This change was due to the identification of severe osteopenia and the determination that pedicle screw purchase was poor. One patient was lost to follow-up. Thus, 51 patients were in Group I, 35 in Group II, and 37 in Group III. Follow-up ranged from 9 to 28 months, averaging 16 months.(ABSTRACT TRUNCATED AT 250 WORDS)Spine 07/1993; 18(8):983-91. · 2.16 Impact Factor
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ABSTRACT: This study was designed to assess both lumbar sagittal balance and clinical outcomes of decompression and posterolateral fusion for degenerative lumbar spondylolisthesis. As an index for the radiologic evaluation of sagittal alignment, the L1 axis S1 distance was used (i.e., the horizontal distance from the plumbline of the center in the L1 to the back corner of the S1). To determine whether lumbar sagittal balance affected the clinical outcome after posterolateral fusion. Little is known about whether the sagittal vertical axis influences clinical outcomes in cases of degenerative lumbar spondylolisthesis. A retrospective review of 47 patients (15 men and 32 women), ranging in age from 41 to 79 years, was conducted. The mean follow-up period was 3.6 years. Relations among outcomes including the visual analog pain scale, recovery rate, L1 axis S1 distance, slippage, and lumbar lordosis were evaluated. Recovery rates were 44% and 62% in patients whose preoperative L1 axis S1 distance, respectively, was more than 35 mm (Group A, n = 16) and less than 35 mm (Group B, n = 31) (P < 0.05). Follow-up assessment found a positive correlation between only lordosis and recovery rate. Severe low back pain and lower recovery rate were observed in patients with in situ fusion in Group A (n = 9), as compared with patients with reduced slippage in Group A (n = 7) and patients in Group B. Both preoperative L1 axis S1 distance and lordosis at follow-up assessment affected surgical outcome. Reduction of slippage may improve clinical outcomes of posterolateral fusion for degenerative lumbar spondylolisthesis with an L1 axis S1 distance more than 35 mm.Spine 02/2002; 27(1):59-64. · 2.16 Impact Factor