Radiological and clinical long-term results of heterotopic ossification following lumbar total disc replacement

Background

The long-term results of heterotopic ossification (HO) following lumbar total disc replacement (TDR) and the corresponding clinical and radiological outcomes are unclear.

Charité total disc replacement—clinical and radiographical results after an average follow-up of 17 years

A retrospective clinical–radiological study to evaluate the long-term outcome after artificial disc replacement was performed. The objective is to investigate long-term results after implantation of a modular type artificial disc prosthesis in patients with degenerative disc disease (DDD). Total disc replacement (TDR) is a surgical procedure intended to save segmental spinal function, and thus replace spondylodesis. Short-term results are promising, whereas long-term results are scarce. The Charité TDR is the oldest existing implant, therefore, the longest possible follow-up is presented here. Seventy-one patients were treated with 84 Charité TDRs types I–III. Indication for TDR was moderate to severe DDD. Fifty-three patients (63 TDRs) were available for long-term follow-up of 17 years. Evaluation included Oswestry disability index, visual analog scale, overall outcome score, plain and extension/flexion radiographs. Implantation of Charité TDR resulted in a 60% rate of spontaneous ankylosis after 17 years. No significant difference between the three types of prostheses was found concerning clinical outcome. Reoperation was necessary in 11% of patients. Although no adjacent segment degeneration was observed in the functional implants (17%), these patients were significantly less satisfied than those with spontaneous ankylosis. TDR, nowadays, is an approved procedure. Proof that long-term results of TDR implantation in DDD are at least as good as fusion results is still missing.     

Anterior discectomy and total disc replacement for three patients with multiple recurrent lumbar disc herniations

Background context

Although results of primary discectomy are generally excellent with relief of leg pain, recurrent lumbar disc herniation is relatively common ranging from 5% to 25%. Patients with recurrent herniation may undergo revision surgery; however, this carries with it increased risks and lower success rates. Many surgeons will advocate a fusion in addition to repeat discectomy after the third recurrent herniated disc. With the approval of lumbar total disc arthroplasty, there now exists another option for the patient with three or more recurrent disc herniations to preserve motion, theoretically decrease the rate of adjacent-level disease, and ameliorate the patient’s symptoms.

Purpose

The purpose of this case report is to describe our experience using total disc replacement (TDR) in three patients after prior partial hemilaminectomy and discectomy for the treatment of a third and fourth recurrent lumbar disc herniation.

Study design

This article is a report of three cases from a spine specialty center describing an alternative surgical technique for patients with multiple recurrent lumbar disc herniation.

Methods

Comprehensive chart review of three patients with recurrent lumbar herniation who underwent TDR.

Results

Anterior discectomy and TDR were undertaken, and at most recent follow-up (8–12 months), all patients had improvement of their visual analog scale and Oswestry Disability Index. No patient had postoperative complications or reoperation.

Conclusions

Recurrent disc herniation is a relatively common problem that may be difficult to treat. Traditionally, a patient presenting with three or more recurrent disc herniation may likely have undergone revision discectomy with fusion. The current case report suggests that TDR may be an alternative option in select patients.     

Mid- to long-term results of total lumbar disc replacement: a prospective analysis with 5- to 10-year follow-up

Background contextThe role of fusion of lumbar motion segments for the treatment of intractable low back pain (LBP) from degenerative disc disease (DDD) without deformities or instabilities remains controversially debated. Total lumbar disc replacement (TDR) has been used as an alternative in a highly selected patient cohort. However, the amount of long-term follow-up (FU) data on TDR is limited. In the United States, insurers have refused to reimburse surgeons for TDRs for fear of delayed complications, revisions, and unknown secondary costs, leading to a drastic decline in TDR numbers.PurposeTo assess the mid- and long-term clinical efficacy as well as patient safety of TDR in terms of perioperative complication and reoperation rates.Study design/settingProspective, single-center clinical investigation of TDR with ProDisc II (Synthes, Paoli, PA, USA) for the treatment of LBP from lumbar DDD that has proven unresponsive to conservative therapy.Patient samplePatients with a minimum of 5-year FU after TDR, performed for the treatment of intractable and predominant (≥80%) axial LBP resulting from DDD without any deformities or instabilities.Outcome measuresVisual analog scale (VAS), Oswestry Disability Index (ODI), and patient satisfaction rates (three-scale outcome rating); complication and reoperation rates as well as elapsed time until revision surgery; patient's professional activity/employment status.MethodsClinical outcome scores were acquired within the framework of an ongoing prospective clinical trial. Patients were examined preoperatively, 3, 6, and 12 months postoperatively, annually from then onward. The data acquisition was performed by members of the clinic's spine unit including medical staff, research assistants, and research nurses who were not involved in the process of pre- or postoperative decision-making.ResultsThe initial cohort consisted of 201 patients; 181 patients were available for final FU, resembling a 90.0% FU rate after a mean FU of 7.4 years (range 5.0–10.8 years). The overall results revealed a highly significant improvement from baseline VAS and ODI levels at all postoperative FU stages (p<.0001). VAS scores demonstrated a slight (from VAS 2.6 to 3.3) but statistically significant deterioration from 48 months onward (p<.05). Patient satisfaction rates remained stable throughout the entire postoperative course, with 63.6% of patients reporting a highly satisfactory or a satisfactory (22.7%) outcome, whereas 13.7% of patients were not satisfied. The overall complication rate was 14.4% (N=26/181). The incidence of revision surgeries for general and/or device-related complications was 7.2% (N=13/181). Two-level TDRs demonstrated a significant improvement of VAS and ODI scores in comparison to baseline levels (p<.05). Nevertheless, the results were significantly inferior in comparison to one-level cases and were associated with higher complication (11.9% vs. 27.6%; p=.03) and inferior satisfaction rates (p<.003).ConclusionsDespite the fact that the current data comprises the early experiences and learning curve associated with a new surgical technique, the results demonstrate satisfactory and maintained mid- to long-term clinical results after a mean FU of 7.4 years. Patient safety was proven with acceptable complication and reoperation rates. Fear of excessive late complications or reoperations following the primary TDR procedure cannot be substantiated with the present data. In carefully selected cases, TDR can be considered a viable treatment alternative to lumbar fusion for which spine communities around the world seem to have accepted mediocre clinical results as well as obvious and significant drawbacks.     

Motion preservation following total lumbar disc replacement at the lumbosacral junction: a prospective long-term clinical and radiographic investigation

Background Context

Total lumbar disc replacement (TDR) intends to avoid fusion-related negative side effects by means of motion preservation. Despite their widespread use, the adequate quality and quantity of motion, as well as the correlation between radiographic data with the patient's clinical symptomatology, remains to be established. Long-term data are lacking in particular.

Influence of lumbar intervertebral disc degeneration on the outcome of total lumbar disc replacement: a prospective clinical, histological, X-ray and MRI investigation

Introduction

The role of fusion of lumbar motion segments for the treatment of axial low back pain (LBP) from lumbar degenerative disc disease (DDD) without any true deformities or instabilities remains controversially debated. In an attempt to avoid previously published and fusion-related negative side effects, motion preserving technologies such as total lumbar disc replacement (TDR) have been introduced. The adequate extent of preoperative DDD for TDR remains unknown, the number of previously published studies is scarce and the limited data available reveal contradictory results. The goal of this current analysis was to perform a prospective histological, X-ray and MRI investigation of the index-segment’s degree of DDD and to correlate these data with each patient’s pre- and postoperative clinical outcome parameters from an ongoing prospective clinical trial with ProDisc II (Synthes, Paoli, USA).

Materials and methods

Nucleus pulposus (NP) and annulus fibrosus (AF) changes were evaluated according to a previously validated quantitative histological degeneration score (HDS). X-ray evaluation included assessment of the mean, anterior and posterior disc space height (DSH). MRI investigation of DDD was performed on a 5-scale grading system. The prospective clinical outcome assessment included Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) scores as well as the patient’s subjective satisfaction rates.

Results

Data from 51 patients with an average follow-up of 50.5 months (range 6.1–91.9 months) were included in the study. Postoperative VAS and ODI scores improved significantly in comparison to preoperative levels (p < 0.002). A significant correlation and interdependence was established between various parameters of DDD preoperatively (p < 0.05). Degenerative changes of NP tissue samples were significantly more pronounced in comparison to those of AF material (p < 0.001) with no significant correlation between each other (p > 0.05). Preoperatively, the extent of DDD was not significantly correlated with the patient’s symptomatology (p > 0.05). No negative influence was associated with increasing stages of DDD on the postoperative clinical outcome parameters following TDR (p > 0.05). Increasing stages of DDD in terms of lower DSH scores were not associated with inferior clinical results as outlined by postoperative VAS or ODI scores or the patient’s subjective outcome evaluation at the last FU examination (p > 0.05). Conversely, some potential positive effects on the postoperative outcome were observed in patients with advanced stages of preoperative DDD. Patients with more severe preoperative HDS scores of NP samples demonstrated significantly lower VAS scores during the early postoperative course (p = 0.02).

Conclusion

Increasing stages of DDD did not negatively impact on the outcome following TDR in a highly selected patient population. In particular, no preoperative DDD threshold value was identified from which an inferior postoperative outcome could have been deduced. Conversely, some positive effects on the postoperative outcome were detected in patients with advanced stages of DDD. Combined advantageous effects of progressive morphological structural rigidity of the index segment and restabilizing effects from larger distraction in degenerated segments may compensate for increasing axial rotational instability, one of TDR’s perceived disadvantages. Our data reveal a “therapeutic window” for TDR in a cohort of patients with various stages of DDD as long as preoperative facet joint complaints or degenerative facet arthropathies can be excluded and stringent preoperative decision making criteria are adhered to. Previously published absolute DSH values as contraindication against TDR should be reconsidered.     

A meta-analysis of artificial total disc replacement versus fusion for lumbar degenerative disc disease

Lumbar fusion has been developed for several decades and became the standard surgical treatment for symptomatic lumbar degenerative disc disease (DDD). Artificial total disc replacement (TDR), as an alternative for spinal arthrodesis, is becoming more commonly employed treating lumbar DDD. It is still uncertain whether TDR is more effective and safer than lumbar fusion. To systematically compare the effectiveness and safety of TDR to that of the fusion for the treatment of lumbar DDD, we performed a meta-analysis. Cochrane review methods were used to analyze all relevant randomized controlled trials published up to July 2009. Five relevant randomized controlled trials involving 837 patients were identified. Patients in TDR group have sightly better functioning and less back or leg pain without clinical significance, and significantly higher satisfaction status in TDR group compared with lumbar fusion group at the 2-year follow-up. But these outcomes are highly influenced by the study with BAK cage interbody fusion, the function/pain and patient satisfaction status are no longer significantly different between two groups after excluding this study. At 5 years, these outcomes are not significantly different between comparing groups. The complication and reoperation rate of two groups are similar both at 2 and at 5 years. In conclusion, TDR does not show significant superiority for the treatment of lumbar DDD compared with fusion. The benefits of motion preservation and the long-term complications are still unable to be concluded. More high-quality RCTs with long-term follow-up are needed.     

Parameters influencing the outcome after total disc replacement at the lumbosacral junction. Part 2: distraction and posterior translation lead to clinical failure after a mean follow-up of 5 years

Purpose

The aim of the second part of the study was to investigate the influence of parameters that lead to increased facet joint contact or capsule tensile forces (disc height, lordosis, and sagittal misalignment) on the clinical outcome after total disc replacement (TDR) at the lumbosacral junction.

Methods

A total of 40 patients of a prospective cohort study who received TDR because of degenerative disc disease or osteochondrosis L5/S1 were invited to an additional follow-up for clinical (ODI and VAS for overall, back, and leg pain) and radiographic analysis (a change in disc height, lordosis, or sagittal vertebral misalignment compared with the preoperative state). Based on the final ODI, patients were retrospectively distributed into groups N (normal: <25 %) or F (failure ≥25 %) for radiographic parameter comparison. A correlation analysis was performed between the clinical and radiological results.

Results

A total of 34 patients were available at a mean follow-up of 59.5 months. Both groups (N = 24; F = 10 patients) presented a significant improvement in overall pain, back pain, and ODI over time. At the final follow-up, higher clinical scores correlated with a larger disc height, increased lordosis, and posterior translation of the superior vertebra, which was also reflected by significant differences in these parameters in the group comparison.

Conclusions

Parameters associated with increased facet joint capsule tensile forces lead to an inferior clinical outcome at mid-term follow-up. When performing TDR, we therefore suggest avoiding iatrogenic posterior translation and overdistraction (and consecutive lordosis).     

Five-year follow-up of clinical and radiological outcomes of LP-ESP elastomeric lumbar total disc replacement in active patients

Background context

The surgical treatment of degenerative disc disease at the lumbar spine may involve fusion. Total disc replacement (TDR) is an alternative treatment to avoid fusion-related adverse events, specifically adjacent segment disease. New generation of elastomeric non-articulating devices has been developed to more effectively replicate the shock absorption and flexural stiffness of native disc.

Bryan颈椎人工椎间盘置换术的长期疗效观察

目的 评估Bryan颈椎人工椎间盘置换术的长期疗效。方法 对2004年12月至2008年8月于我院行Bryan颈椎人工椎间盘置换术的20例病人进行回顾性分析,男15例,女5例,平均年龄为（43.85±3.70）岁,其中单节段9例,双节段11例,C_3/4 2例、C_4/5 9例、C_5/6 15例、C_6/7 5例。①收集并比较其术前、术后1周、术后2年及末次随访的改良日本骨科协会（modified Japanese Orthopaedic Association, mJOA）评估治疗分数、疼痛视觉模拟量表（visual analogue scale, VAS）评分、颈椎功能障碍指数（neck disability index, NDI）以及Odom''s分级。②通过其术前、术后早期及末次随访时的X线侧位片及颈椎过屈过伸位片,评估其颈椎曲度、颈椎活动度（ROM）。③MRI T2加权像上根据Miyazaki分级标准评估Bryan人工椎间盘置换术后邻近节段的退变情况。④通过X线片及CT片根据McAfee标准评价异位骨化的发生情况。结果 ①术前及末次随访时的mJOA评分分别为（13.30±2.83）分、（15.25±2.07）分,VAS评分分别为（4.10±3.81）分、（1.55±1.53）分,NDI分别为（11.45±9.52）分、（6.00±4.78）分,所有评价指标末次随访时较术前均有显著改善,差异均有统计学意义（P均＜0.05）。末次随访时Odom''s分级为优8例,良8例,可2例,差2例。②脊柱功能单位（FSU）曲度及C₂~C₇曲度：术前分别为2.33°±4.08°、18.78°±6.68°,术后早期为4.12°±6.43°、20.00°±9.98°,末次随访时分别为3.21°±6.56°、15.61°±6.73°。FSU ROM及C₂~C₇ ROM：术前分别为9.15°±2.80°、47.28°±9.75°,术后早期为9.27°±3.83°、40.81°±14.66°,末次随访分别为9.37°±3.97°、42.03°±10.97°。3个时间点的FSU曲度及FSU ROM比较,差异均无统计学意义（P均＞0.05）,但C₂~C_{7 ROM术后较术前明显减少,与邻近节段ROM变化趋势一致。末次随访时,43个邻近节段中46.5%发生邻近节段退变（adjacent segment degeneration, ASD）,以C5/6最为常见,但均无临床表现;末次随访时31个手术节段中有23例（74.2%）发生异位骨化,其中严重异位骨化（Ⅲ、Ⅳ级）发生率为22.6%,C5/6最为常见。结论 Bryan颈椎人工椎间盘置换术治疗颈椎退变性疾病可以取得持久稳定的临床效果,尽管异位骨化发生率较高,但大部分保留手术节段活动,同时邻近节段仍可见退变,但均无临床症状。}     

椎间盘切除Dynesys动态稳定系统固定治疗腰椎间盘突出症的中长期疗效

目的 :回顾性分析椎间盘切除+Dynesys动态稳定系统固定治疗腰椎间盘突出症的中长期疗效。方法 :2008年7月~2012年7月因腰椎间盘突出症在我院行椎间盘切除+Dynesys动态稳定系统内固定治疗的患者84例,其中61例获得完整随访资料,男38例,女23例;年龄31~58岁(46.3±11.5岁),随访时间60~108个月(74±14个月)。术前、术后3个月和末次随访时采用疼痛视觉模拟评分(visual analogue scale,VAS)和Oswestry功能障碍指数(Oswestry disability index,ODI)评估,同时行影像学评估,包括手术节段及上位相邻节段椎间隙高度、椎间活动度(rang of motion,ROM)、UCLA椎间隙退变分级(University of California at Los Angeles)以及椎间盘退变Pfirrmann分级。结果:术后3个月、末次随访时VAS评分和ODI均较术前明显改善(P0.05),所有病例均未见椎间盘突出复发。手术节段椎间隙高度术后3个月(12.3±2.3mm)较术前(11.8±1.8mm)增加,末次随访时(10.1±1.7mm)较术前降低(P0.05);上位相邻节段各时间点无显著性差异。手术节段椎间ROM在术后3个月及末次随访分别为5.3°±1.8°及3.6°±1.9°,与术前(8.1°±2.8°)比较均显著性降低(P0.05);上位相邻节段ROM在术后3个月和末次随访分别10.3°±3.8°和11.4°±3.7°,均较术前(8.5°±3.0°)显著性增加(P0.05)。末次随访时手术节段UCLA分级与术前比较有统计学差异(P0.05),12例(19.7%)上位相邻节段发生影像学退变,1例发生症状学退变(adjacent segment degeneration,ASD)。手术节段和上位邻近节段术前与末次随访椎间盘Pfirmman分级均有统计学差异(P0.05)。2例出现螺钉断裂,未发生螺钉松动等其他并发症。结论:腰椎间盘切除后应用Dynesys动态稳定系统内固定治疗腰椎间盘突出症可获得满意的中长期疗效,能维持手术节段稳定,保留手术节段部分椎间活动度。     

Lumbar and cervical viscoelastic disc replacement: Concepts and current experience

The ideal lumbar and cervical discs should provide six degrees of freedom and tri-planar (three-dimensional) motion. Although all artificial discs are intended to achieve the same goals, there is considerable heterogeneity in the design of lumbar and cervical implants. The “second generation total disc replacements” are non-articulating viscoelastic implants aiming at the reconstruction of physiologic levels of shock absorption and flexural stiffness. This review aims to give an overview of the available implants detailing the concepts and the functional results experimentally and clinically. These monobloc prostheses raise new challenges concerning the choice of materials for the constitution of the viscoelastic cushion, the connection between the components of the internal structure and the metal endplates and even the bone anchoring mode. New objectives concerning the quality of movement and mobility control must be defined.     

前路小切口人工髓核置换术治疗退变性腰椎间盘疾患的远期效果

目的:分析前路经小切口行人工髓核(prosthetic disc nucleus,PDN)置换治疗退变性腰椎间盘疾患的远期效果。方法:2003年6月～2004年9月共行前路L4/5单间隙PDN置换术12例,其中男4例,女8例,年龄18～42岁,平均28.5±8.4岁。腰椎间盘突出症10例,椎间盘源性腰痛2例。术前、术后3个月、术后1年和末次随访时行腰、腿痛视觉模拟评分(visual analoge scale,VAS)和Oswestry功能障碍指数(ODI)评定,应用MacNab标准评价临床疗效,影像学观察假体位置、手术及上位相邻节段椎间隙高度和腰椎运动范围(range of motion,ROM),并进行统计学分析。结果:术后随访60～89个月,平均73.6±8.3个月,腿痛与腰痛VAS、ODI评分术后3个月与术前、术后1年与术后3个月比较有显著性改善(P<0.05),末次随访与术后1年比较无显著性差异(P>0.05);手术节段椎间隙高度术后3个月与术前、术后1年与术后3个月比较有显著性增加(P<0.05),末次随访与术后1年比较无显著差异(P>0.05);手术上位相邻节段椎间隙高度术后3个月、术后1年与术前比较无显著性差异,末次随访与术后1年比较无显著性差异(P>0.05);腰椎ROM术后3个月与术前、术后1年与术后3个月比较无显著性差异(P>0.05),末次随访与术后1年比较有显著性减少(P<0.05)。随访过程中无假体脱入椎管、移位和位置不良,末次随访时MacNab优良率为83.3%,MRI T2加权像显示手术节段椎体终板均出现Modic改变。结论:通过前路小切口进行PDN置换可有效防止假体脱入椎管,长期改善临床症状、恢复手术节段椎间隙高度,维持邻近节段椎间隙高度,但手术节段终板损伤较为常见。     

Total lumbar disc replacement in athletes: clinical results,return to sport and athletic performance

Despite the increasing popularity of total lumbar disc replacement (TDR) in predominantly young and active patients, no previous study has addressed possibilities, limitations and potential risks regarding athletic performance following TDR. Mechanical concerns remain and the implant’s resilience as regards its load-bearing capacity during sporting activities is unknown. Thirty-nine athletic patients fulfilled the inclusion criteria for this study. These patients participated in a large variety of different types of sport. Significant and lasting pain-relief was attained following TDR with a mean follow-up of 26.3 months (range 9–50.7 months; FU rate 97.4%). Sporting activity was resumed within the first 3 months (38.5%) to 6 months (30.7%) with peak performance being reached after 5.2 months. Thirty-seven patients (94.9%) achieved resumption of sporting activity. Athletic performance improved significantly in 33 patients (84.6%). Minor subsidence was observed in 13 patients (30%) within the first 3 months with no further implant migration thereafter in 12 patients. Participation in all types of sport recorded in this study was accessible for a high rate of patients up to the level of professional athletes as well as those participating in extreme sports. Preoperative participation in sport proved to be a strong positive predictor for highly satisfactory postoperative outcome following TDR. In a selected group of patients, however, preoperative inability to participate in sporting activities did not impair postoperative physical activity. Due to the young age of the patients and significant load increase exerted during athletic activities, persisting concerns regarding the future behaviour of the implant remain and will require longer follow-up, modified investigation techniques and larger patient cohorts.     

Hybrid construct for two levels disc disease in lumbar spine

Prospective study. To study the validity of Hybrid construction (Anterior Lumbar Interbody Fusion) ALIF at one level and total disc arthroplasty (TDA) at adjacent, for two levels disc disease in lumbar spine as surgical strategy. With growing evidence that fusion constructs in the treatment of degenerative disc disease (DDD) may alter sagittal balance and contribute to undesirable complications in the long-term, total disc arthroplasty (TDA) slowly becomes an accepted treatment option for a selected group of patients. Despite encouraging early and intermediate term results of single-level total disc arthroplasty reported in the literature, there is growing evidence that two-level arthroplasty does not fare as well. Hybrid fusion is an attempt to address two-level DDD by combining the advantages of a single-level ALIF with those of a single-level arthroplasty. 42 patients (25 females and 17 males) underwent Hybrid fusion and had a median follow-up of 26.3 months. The primary functional outcomes were assessed before and after surgery with Oswestry Disability Index and the visual analogue score of the back and legs. Patients were divided into four groups according to the percentage improvement between preop and postop ODI scores. A total of 42 patients underwent a hybrid fusion as follows: 35 L5-S1 ALIF/L4-5 prosthesis, 3 L4-5 ALIF/L3-4 prosthesis, 2 L5-S1 ALIF/L4-5 prosthesis/L3-4 prosthesis, 1 L5-S1 prosthesis/L4-5 ALIF, and 1 L5-S1 ALIF/L4-5 ALIF/L3-4 prosthesis. At 2-years clinical outcomes, mean reduction in ODI is 24.9 points (53.0% improvement compared to preop ODI). The visual analogue score for the back is 64.6% improvement. At 2-year clinical outcomes, Hybrid fusion is a viable surgical alternative for the treatment of two-level DDD in comparison with two-level TDA and with two-level fusion.     

Clinical outcomes,radiologic kinematics,and effects on sagittal balance of the 6 df LP-ESP lumbar disc prosthesis

Background contextSurgical treatment of degenerative disc disease remains a controversial subject. Lumbar fusion has been associated with a potential risk of segmental junctional disease and sagittal balance misalignment. Motion preservation devices have been developed as an alternative to fusion. The LP-ESP disc is a one-piece deformable device achieving 6 df, including shock absorption and elastic return. This is the first clinical report on its use.PurposeTo assess clinical outcomes and radiologic kinematics in the first 2 years after implantation.Study designProspective cohort of patients with LP-ESP total disc replacement (TDR) at the lumbar spine.Patient sampleForty-six consecutive patients.Outcome measuresClinical outcomes were the visual analog scale (VAS) for pain, the Oswestry disability index (ODI), and the GHQ28 (General Health Questionnaire) psychological score. Radiologic data were the range of motion (ROM), sagittal balance parameters, and mean center of rotation (MCR).MethodsPatients had single-level TDR at L4–L5 or L5–S1. Outcomes were prospectively recorded for 2 years (before and at 3, 6, 12, and 24 months after surgery). The SpineView software was used for computed analysis of the radiographic data. Paired t tests were used for statistical comparisons.ResultsNo intraoperative complication occurred. All clinical scores improved significantly at 24 months: the back pain VAS scores by a mean of 4.1 points and the ODI by 33 points. The average ROM of the instrumented level was 5.4°±4.8° at 2 years and more than 2° for 76% of prostheses. The MCR was in a physiological area in 73% of cases. The sagittal balance (pelvic tilt, sacral slope, and segmental lordosis) did not change significantly at any point of the follow-up.ConclusionsResults from the 2-year follow-up indicate that LP-ESP prosthesis recreates lumbar spine function similar to that of the healthy disc in terms of ROM, quality of movement, effect on sagittal balance, and absence of modification in the kinematics of the upper adjacent level.     

Stand-alone lateral lumbar interbody fusion for the treatment of symptomatic adjacent segment degeneration following previous lumbar fusion

Background Context

Revision posterior decompression and fusion surgery for patients with symptomatic adjacent segment degeneration (ASD) is associated with significant morbidity and is technically challenging. The use of a stand-alone lateral lumbar interbody fusion (LLIF) in patients with symptomatic ASD may prevent many of the complications associated with revision posterior surgery.

Total disc replacement surgery for symptomatic degenerative lumbar disc disease: a systematic review of the literature

The objective of this study is to evaluate the effectiveness and safety of total disc replacement surgery compared with spinal fusion in patients with symptomatic lumbar disc degeneration. Low back pain (LBP), a major health problem in Western countries, can be caused by a variety of pathologies, one of which is degenerative disc disease (DDD). When conservative treatment fails, surgery might be considered. For a long time, lumbar fusion has been the “gold standard” of surgical treatment for DDD. Total disc replacement (TDR) has increased in popularity as an alternative for lumbar fusion. A comprehensive systematic literature search was performed up to October 2008. Two reviewers independently checked all retrieved titles and abstracts, and relevant full text articles for inclusion. Two reviewers independently assessed the risk of bias of included studies and extracted relevant data and outcomes. Three randomized controlled trials and 16 prospective cohort studies were identified. In all three trials, the total disc replacement was compared with lumbar fusion techniques. The Charité trial (designed as a non-inferiority trail) was considered to have a low risk of bias for the 2-year follow up, but a high risk of bias for the 5-year follow up. The Charité artificial disc was non-inferior to the BAK^® Interbody Fusion System on a composite outcome of “clinical success” (57.1 vs. 46.5%, for the 2-year follow up; 57.8 vs. 51.2% for the 5-year follow up). There were no statistically significant differences in mean pain and physical function scores. The Prodisc artificial disc (also designed as a non-inferiority trail) was found to be statistically significant more effective when compared with the lumbar circumferential fusion on the composite outcome of “clinical success” (53.4 vs. 40.8%), but the risk of bias of this study was high. Moreover, there were no statistically significant differences in mean pain and physical function scores. The Flexicore trial, with a high risk of bias, found no clinical relevant differences on pain and physical function when compared with circumferential spinal fusion at 2-year follow up. Because these are preliminary results, in addition to the high risk of bias, no conclusions can be drawn based on this study. In general, these results suggest that no clinical relevant differences between the total disc replacement and fusion techniques. The overall success rates in both treatment groups were small. Complications related to the surgical approach ranged from 2.1 to 18.7%, prosthesis related complications from 2.0 to 39.3%, treatment related complications from 1.9 to 62.0% and general complications from 1.0 to 14.0%. Reoperation at the index level was reported in 1.0 to 28.6% of the patients. In the three trials published, overall complication rates ranged from 7.3 to 29.1% in the TDR group and from 6.3 to 50.2% in the fusion group. The overall reoperation rate at index-level ranged from 3.7 to 11.4% in the TDR group and from 5.4 to 26.1% in the fusion group. In conclusion, there is low quality evidence that the Charité is non-inferior to the BAK cage at the 2-year follow up on the primary outcome measures. For the 5-year follow up, the same conclusion is supported only by very low quality evidence. For the ProDisc, there is very low quality evidence for contradictory results on the primary outcome measures when compared with anterior lumbar circumferential fusion. High quality randomized controlled trials with relevant control group and long-term follow-up is needed to evaluate the effectiveness and safety of TDR.     

Thoracal flat back is a risk factor for lumbar disc degeneration after scoliosis surgery

Background contextLumbar segments below fused scoliotic spines are thought to be exposed to extraordinary stress. Although positive sagittal imbalance has come into focus, reports about factors influencing the outcome of these segments remain inconclusive.PurposeOur study aimed at identifying spinal risk factors for the development of lumbar degenerative disc disease (DDD) in surgically treated patients with adolescent idiopathic scoliosis (AIS).Study design/settingRetrospective comparative prognostic study (Level III) was conducted. Thirty-three patients were seen at an average follow-up of 7.5 years after either isolated selective anterior (n=18) or long combined anterior-posterior fusion (n=15) for AIS.Outcome measuresSelf-reported Scoliosis Research Society 22 questionnaire, physical examination including the detection of segmental pain and unspecific back pain, preoperative and postoperative whole-spine standing radiographs, and magnetic resonance imaging were obtained.MethodsRadiographic evaluation included the measurement of regional, coronal, and sagittal curve parameters and the assessment of spinal balance. Magnetic resonance imaging evaluation was done for preoperative and postoperative lumbar discs, according to the classification of Pfirrmann.ResultsPatients with low DDD (Pfirrmann grading <3) had a significantly higher thoracal kyphosis angle (mean 28°) than patients with advanced DDD (mean 15°). There was a trend toward a more flat-type lumbar lordosis in patients with severe DDD. Positive sagittal imbalance was associated with advanced DDD. Follow-up coronal parameters, trunk imbalance, instrumentation length, and lowest instrumented vertebra selection had no influence on DDD. Specific segmental pain could be attributed to a significantly higher coronal trunk imbalance (21 vs. 11 mm).ConclusionsThis study establishes thoracal flat back as a risk factor for lumbar DDD after spinal fusion and supports the pathogenetic role of positive sagittal imbalance in this process.