The Biomechanical Effect of Postoperative Hypolordosis in Instrumented Lumbar Fusion on Instrumented and Adjacent Spinal Segments

Umehara, Shinji; Zindrick, Michael R.; Patwardhan, Avinash G.; Havey, Robert M.; Vrbos, Lori; Knight, Gary W.; Miyano, Suichi; Kirincic, Marie; Kaneda, Kiyoshi; Lorenz, Mark

doi:10.1097/00007632-200007010-00004

Cited by 254 publications

(151 citation statements)

References 23 publications

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“…However, adjacent segment degeneration (ASD) has been reported as a long-term complication with an incidence ranging from 10 to 100% [15,16]. The overall revision rate for symptomatic ASD ranges from 2.7 to 20% [17]. Since the 1980s, non-rigid, dynamic implants have been studied in an attempt to reduce ASD.…”

Section: Discussionmentioning

confidence: 99%

Biomechanical evaluation of posterior lumbar dynamic stabilization: an in vitro comparison between Universal Clamp and Wallis systems

et al. 2010

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Treatment of chronic low back pain due to degenerative lumbar spine conditions often involves fusion of the symptomatic level. A known risk of this procedure is accelerated adjacent level degeneration. Motion preservation devices have been designed to provide stabilization to the symptomatic motion segment while preserving some physiologic motion. The aim of this study was to compare the changes in relative range of motion caused as a result of application of two non-fusion, dynamic stabilization devices: the Universal Clamp (UC) and the Wallis device. Nine fresh, frozen human lumbar spines (L1-Sacrum) were tested in flexion-extension, lateral bending, and axial rotation with a custom spine simulator. Specimens were tested in four conditions: (1) intact, (2) the Universal Clamp implanted at L3-4 (UC), (3) the UC with a transverse rod added (UCTR), and (4) the Wallis device implanted at L3-4. Total range of motion at 7.5 N-m was determined for each device and compared to intact condition. The UC device (with or without a transverse rod) restricted motion in all planes more than the Wallis. The greatest restriction was observed in flexion. The neutral position of the L3-4 motion segment shifted toward extension with the UC and UCTR. Motion at the adjacent levels remained similar to that observed in the intact spine for all three constructs. These results suggest that the UC device may be an appropriate dynamic stabilization device for degenerative lumbar disorders.

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Section: Discussionmentioning

confidence: 99%

Biomechanical evaluation of posterior lumbar dynamic stabilization: an in vitro comparison between Universal Clamp and Wallis systems

et al. 2010

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“…These post-operative pain patterns have been linked to increased stress distribution and motion adjacent to the fused segments as well as to pathologically altered lumbar segmental, sagittal and spinopelvic alignment [1,21,29,32,35,42,43,63]. The reported incidence of symptomatic ''fusion-related'' pain patterns from posterior joint structures ranges from 32 to 61%, and it's clinical relevance has been confirmed in a variety of studies using fluoroscopically guided spine infiltrations [29,42,43].…”

Section: Introductionmentioning

confidence: 97%

Analysis of post-operative pain patterns following total lumbar disc replacement: results from fluoroscopically guided spine infiltrations

Siepe¹,

Korge²,

Grochulla³

et al. 2007

Eur Spine J

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Although a variety of biomechanical laboratory investigations and radiological studies have highlighted the potential problems associated with total lumbar disc replacement (TDR), no previous study has performed a systematic clinical failure analysis. The aim of this study was to identify the post-operative pain sources, establish the incidence of post-operative pain patterns and investigate the effect on post-operative outcome with the help of fluoroscopically guided spine infiltrations in patients from an ongoing prospective study with ProDisc II. Patients who reported unsatisfactory results at any of the FU-examinations received fluoroscopically guided spine infiltrations as part of a semi-invasive diagnostic and conservative treatment program. Pain sources were identified in patients with reproducible (C29) significant (50-75%) or highly significant (75-100%) pain relief. Results were correlated with outcome parameters visual analogue scale (VAS), Oswestry disability index (ODI) and the subjective patient satisfaction rate. From a total of 175 operated patients with a mean follow-up (FU) of 29.3 months (range 12.2-74.9 months), n = 342 infiltrations were performed in n = 58 patients (33.1%) overall. Facet joint pain, predominantly at the index level (86.4%), was identified in n = 22 patients (12.6%). The sacroiliac joint was a similarly frequent cause of post-operative pain (n = 21, 12.0%). Pain from both structures influenced all outcome parameters negatively (P \ 0.05). Patients with an early onset of pain (B6 months) were 2-59 higher at risk of developing persisting complaints and unsatisfactory outcome at later FU-stages in comparison to the entire study cohort (P \ 0.05). The level of TDR significantly influenced postoperative outcome. Best results were achieved for the TDRs above the lumbosacral junction at L4/5 (incidence of posterior joint pain 14.8%). Inferior outcome and a significantly higher incidence of posterior joint pain were observed for TDR at L5/S1 (21.6%) and bisegmental TDR at L4/5/S1 (33.3%), respectively. Lumbar facet and/or ISJpain are a frequent and currently underestimated source of post-operative pain and the most common reasons for unsatisfactory results following TDR. Further failureanalysis studies are required and adequate salvage treatment options need to be established with respect to the underlying pathology of post-operative pain. The question as to whether or not TDR will reduce the incidence of posterior joint pain, which has been previously attributed to lumbar fusion procedures, remains unanswered. Additional studies will have to investigate whether TDR compromises the index-segment in an attempt to avoid adjacent segment degeneration.

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“…Although most often the criteria to determine ASD are based solely on radiographic findings [2,7,19,28,30,34,39,41,59] reporting an ASD incidence ranging from 8 to 100%, the symptomatic incidence of ASD is significantly lower ranging from 5.2 to 18.5% [7,28,31], while the rate of re-operation rate for symptomatic ASD ranges from 2.7 to 20% [16,58].…”

Section: Introductionmentioning

confidence: 99%

“…There is a controversy regarding the risk factors involved in the development of ASD [2,11,12,22,28,40,41,47,[57][58][59]. Non-rigid, dynamic or flexible instrumentations for lumbar spine have been developed to reduce ASD [17,18,27].…”

Section: Introductionmentioning

confidence: 99%

Does Wallis implant reduce adjacent segment degeneration above lumbosacral instrumented fusion?

et al. 2009

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Delayed complications following lumbar spine fusion may occur amongst which is adjacent segment degeneration (ASD). Although interspinous implants have been successfully used in spinal stenosis to authors' knowledge such implants have not been previously used to reduce ASD in instrumented lumbar fusion. This prospective controlled study was designed to investigate if the implantation of an interspinous implant cephalad to short lumbar and lumbosacral instrumented fusion could eliminate the incidence of ASD and subsequently the related reoperation rate. Groups W and C enrolled initially each 25 consecutive selected patients. Group W included patients, who received the Wallis interspinous implant in the unfused vertebral segment cephalad to instrumentation and the group C selected age-, diagnosis-, level-, and instrumentationmatched to W group patients without interspinous implant (controls). The inclusion criterion for Wallis implantation was UCLA arthritic grade \II, while the exclusion criteria were previous lumbar surgery, severe osteoporosis or degeneration[UCLA grade II in the adjacent two segments cephalad to instrumentation. All patients suffered from symptomatic spinal stenosis and underwent decompression and 2-4 levels stabilization with rigid pedicle screw fixation and posterolateral fusion by a single surgeon. Lumbar lordosis, disc height (DH), segmental range of motion (ROM), and percent olisthesis in the adjacent two cephalad to instrumentation segments were measured preoperatively, and postoperatively until the final evaluation. VAS, SF-36, and Oswestry Disability Index (ODI) were used. One patient of group W developed pseudarthrosis: two patients of group C deep infection and one patient of group C ASD in the segment below instrumentation and were excluded from the final evaluation. Thus, 24 patients of group W and 21 in group C aged 65? 13 and 64? 11 years, respectively were included in the final analysis. The follow-up averaged 60 ± 6 months. The instrumented levels averaged 2.5 ? 1 vertebra for both groups. All 45 spines showed radiological fusion 8-12 months postoperatively. Lumbar lordosis did not change postoperatively. Postoperatively at the first cephalad adjacent segment: DH increased in the group W (P = 0.042); ROM significantly increased only in group C (ANOVA, P \ 0.02); olisthesis decreased both in flexion (P = 0.0024) and extension (P = 0.012) in group W. The degeneration or deterioration of already existed ASD in the two cephalad segments was shown in 1 (4.1%) and 6 (28.6%) spines in W and C groups, respectively. Physical function (SF-36) and ODI improved postoperatively (P \ 0.001), but in favour of the patients of group W (P \ 0.05) at the final evaluation. Symptomatic ASD required surgical intervention was in 3 (14%) patients of group C and none in group W. ASD remains a significant problem and accounts for a big portion of revision surgery following instrumented lumbar fusion. In this series, the Wallis interspinous implant changed the natural history of ASD and saved th...

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The Biomechanical Effect of Postoperative Hypolordosis in Instrumented Lumbar Fusion on Instrumented and Adjacent Spinal Segments

Abstract: Hypolordosis in the instrumented segments caused increased loading of the posterior column of the adjacent segments. These biomechanical effects may explain the degenerative changes at the junctional level that have been observed as long-term consequences of lumbar fusion.

Cited by 254 publications

References 23 publications

Biomechanical evaluation of posterior lumbar dynamic stabilization: an in vitro comparison between Universal Clamp and Wallis systems

Biomechanical evaluation of posterior lumbar dynamic stabilization: an in vitro comparison between Universal Clamp and Wallis systems

Analysis of post-operative pain patterns following total lumbar disc replacement: results from fluoroscopically guided spine infiltrations

Does Wallis implant reduce adjacent segment degeneration above lumbosacral instrumented fusion?

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