Comparison of instrumented anterior interbody fusion with instrumented circumferential lumbar fusion

Posterior lumbar interbody fusion (PLIF) restores disc height, the load bearing ability of anterior ligaments and muscles, root canal dimensions, and spinal balance. It immobilizes the painful degenerate spinal segment and decompresses the nerve roots. Anterior lumbar interbody fusion (ALIF) does the same, but could have complications of graft extrusion, compression and instability contributing to pseudarthrosis in the absence of instrumentation. The purpose of this study was to assess and compare the outcome of instrumented circumferential fusion through a posterior approach [PLIF and posterolateral fusion (PLF)] with instrumented ALIF using the Hartshill horseshoe cage, for comparable degrees of internal disc disruption and clinical disability. It was designed as a prospective study, comparing the outcome of two methods of instrumented interbody fusion for internal disc disruption. Between April 1994 and June 1998, the senior author (N.R.B.) performed 39 instrumented ALIF procedures and 35 instrumented circumferential fusion with PLIF procedures. The second author, an independent assessor (S.M.), performed the entire review. Preoperative radiographic assessment included plain radiographs, magnetic resonance imaging (MRI) and provocative discography in all the patients. The outcome in the two groups was compared in terms of radiological improvement and clinical improvement, measured on the basis of improvement of back pain and work capacity. Preoperatively, patients were asked to fill out a questionnaire giving their demographic details, maximum walking distance and current employment status in order to establish the comparability of the two groups. Patient assessment was with the Oswestry Disability Index, quality of life questionnaire (subjective), pain drawing, visual analogue scale, disability benefit, compensation status, and psychological profile. The results of the study showed a satisfactory outcome (score30) on the subjective (quality of life questionnaire) score of 71.8% (28 patients) in the ALIF group and 74.3% (26 patients) in the PLIF group (P>0.05). On categorising Oswestry Index scores into "excellent", "better", "same", and "worse", we found no difference in outcome between the two groups: 79.5% (n=31) had satisfactory outcome with ALIF and 80% (n=28) had satisfactory outcome with PLIF. The rate of return to work was no different in the two groups. On radiological assessment, we found two nonunions in the circumferential fusion (PLIF) group (94.3% fusion rate) and indirect evidence of no nonunions in the ALIF group. There was no significant difference between the compensation rate and disability benefit rate between the two groups. There were three complications in ALIF group and four in the PLIF (circumferential) group. On the basis of these results, we conclude that it is possible to treat discogenic back pain by anterior interbody fusion with Hartshill horseshoe cage or with circumferential fusion using instrumented PLIF.     

Is high level of disability an indication for spinal fusion? Analysis of long-term outcome after posterior lumbar interbody fusion using carbon fiber cages

OBJECTIVE: Posterior lumbar interbody fusion is a recognized procedure for the treatment of back pain associated with degenerative disc disease and segmental instability. It allows decompression of the spinal canal and circumferential fusion through a single posterior incision. METHODS: Sixty-five consecutive patients who underwent posterior lumbar interbody fusion using carbon cages and pedicle fixation between 1993 and 2000 were recruited and contacted with a postal survey. Clinical outcome was assessed by the postoperative clinical findings and complications and the fusion rate, which was assessed using the scoring system described by Brantigan and Steffee. Functional outcome was measured by using improvement in the Oswestry Disability Index, return to work, and satisfaction with the surgical outcome. The determinants of functional relief were analyzed against the improvement in disability using multiple regression analysis. RESULTS: The mean postoperative duration at the time of the study was 4.4 years. Overall radiologic fusion rate was 98%. There was a significant improvement in Oswestry Disability Index (P < 0.01). There was 84% satisfaction with the surgical procedure and 61% return to predisease activity level and full employment. We found preoperative level of disability to be the best determinant of functional recovery irrespective of age or the degree of psychological morbidity and litigation (P < 0.01). CONCLUSION: The combination of posterior lumbar interbody fusion and posterior instrumented fusion is a safe and effective method of achieving circumferential segmental fusion. A direct relationship between preoperative level of disability and functional recovery suggests that disability should be measured preoperatively and spinal fusion should be performed to alleviate disability caused by degenerative spine.     

Posterior lumbar interbody fusion versus posterolateral fusion in spondylolisthesis: a prospective controlled study in the Han nationality

In this prospective study, our aim was to compare the clinical outcome of posterior lumbar interbody fusion (PLIF) and posterolateral fusion (PLF) in spondylolisthesis. A total of 138 patients with spondylolisthesis were randomly assigned to two groups: those operated on with pedicle screw fixation and posterior lumbar interbody fusion by autografting (PLIF), and those operated on with pedicle screw fixation and posterolateral fusion by autografting (PLF). The patients were followed-up for four years. Clinical evaluation was carried out using the Oswestry disability index (ODI) and pain index (VAS). Radiography was performed preoperatively and postoperatively to assess the fusion. Both surgical procedures were effective, but the PLF group showed more complications related to hardware biomechanics. There was no significant statistical difference in clinical and functional outcome in the two groups. The PLIF group presented a better fusion rate than the PLF group.     

Posterior lumbar interbody fusion versus intertransverse fusion in the treatment of lumbar spondylolisthesis

PURPOSE: To compare 2 methods of fusion in the treatment of lumbar spondylolisthesis: posterior lumbar interbody fusion (PLIF) and intertransverse fusion (ITF). METHODS: 20 patients with lumbar spondylolisthesis were randomly allocated to one of 2 groups: decompression, posterior instrumentation, and PLIF (n=10) or decompression, posterior instrumentation, and ITF (n=10). The Oswestry low back pain disability questionnaire was used for clinical assessment. Radiography was performed preoperatively and postoperatively to assess the reduction of spondylolisthesis or slip. RESULTS: In the PLIF and ITF groups, 87.5% and 100% had a satisfactory clinical result, and 48% and 39% had reduced spondylolisthesis, respectively. Both had a fusion rate of 100%. PLIF showed better reduction of spondylolisthesis, although ITF achieved a better subjective and clinical outcome. CONCLUSION: Morbidity and complications are much higher following PLIF than ITF. ITF is recommended because of the simplicity of the procedure, lower complication rate, and good clinical and radiological results.     

复杂性腰椎管狭窄症手术方法比较

目的 评估椎板切除后外侧融合术，椎板切除椎间融合经椎弓根内固定术治疗复杂性腰椎管狭窄患者的术后近，中期疗效。方法 有21例患者接受椎板切除后外侧融合术，22例患者接受椎板切除椎间融合椎弓根内固定术，术后进行Oswestry疗效评定和腰椎影像学观察。结果 术后1年疗效优良率后外侧融合组为81.0%。椎间融合固定组为81.8%。术后1年两组疗效优良率无显著差别。术后4年疗效优良率后外侧融合组为72.2%,椎间融合组为78.9%。术后4后外侧融合组疗效下降显著，椎间融合组疗效下降不显著，结论 椎板切除椎间融合经椎弓根内固定术，椎板切除后外侧融合术治疗复杂性腰椎管狭窄症，术后近期疗效均满意，椎板切除后外侧融合组术后中期疗效下降，其腰椎不稳定和腰椎管再狭窄发生率较高。     

A preliminary comparative study of radiographic results using mineralized collagen and bone marrow aspirate versus autologous bone in the same patients undergoing posterior lumbar interbody fusion with instrumented posterolateral lumbar fusion.

BACKGROUND CONTEXT: Multiple bone graft substitutes for spinal fusion have been studied with varying results. PURPOSE: The purpose of this study was to assess the effectiveness of a mineralized collagen matrix combined with bone marrow, versus autologous bone, in the same patients undergoing a posterior lumbar interbody fusion and an instrumented posterolateral lumbar fusion. STUDY DESIGN/SETTING: A prospective, comparative study. PATIENT SAMPLE: Patients indicated for one-level posterior lumbar interbody fusion and instrumented posterolateral lumbar fusion, serving as self-controls. OUTCOME MEASURES: Thin-cut computed tomographic scans with sagittal reconstruction and plain radiographs, including lateral flexion/extension views were performed and assessed at 12 and 24 months after surgery. Oswestry Disability Index and Visual Analog Scale questionnaires were completed by all patients preoperatively and at 12 and 24 months after surgery. METHODS: After informed consent and failure of nonoperative treatment, 25 consecutive patients requiring one-level instrumented posterolateral fusion combined with posterior interbody fusion were enrolled in the study. Mineralized collagen bone graft substitute combined with bone marrow aspirate was used on one side of the posterolateral fusion, with iliac crest autograft on the contralateral side. RESULTS: A fusion rate of 84% (21/25) was achieved for the autologous bone grafts and 80% (20/25) for the bone graft substitute. The interbody fusion rate was 92% (23/25). Mean Oswestry Disability Index (ODI) scores decreased 57.2% at 12 months and 55.6% at 24 months, compared with baseline. CONCLUSIONS: Mineralized collagen bone graft substitute exhibited similar radiographic results compared with autograft in this model. Further trials incorporating bilateral fusion, as well as posterolateral fusion alone without interbody fusion are warranted to confirm the results of this study.     

Does provocative discography screening of discogenic back pain improve surgical outcome?

The value of preoperative provocative discography in the setting of discogenic low back pain was investigated by evaluating surgical outcomes. Seventy-three consecutive patients who underwent posterolateral interbody and posterior spinal arthrodesis for discogenic low back pain refractory to nonoperative management were reviewed. Chronologically, the first 41 patients (group A) were indicated without discography, whereas the remaining 32 (group B) had been indicated only if their pain had been reproduced during disc injection. The two groups were similar in demographic, psychometric, and radiologic parameters. Average follow-up time in group A was 2.8 years and in group B it was 2.4 years, both with a 2-year minimum. Using modified Oswestry scoring, group A and group B patients had satisfactory outcomes of 75.6% and 81.2%, respectively. This difference was neither statistically significant nor suggestive. In this study, provocative discography screening did not improve surgical outcomes after circumferential fusion for lumbar discogenic back pain.     

两种融合手术治疗腰椎滑脱症的影像学及临床疗效比较

目的 比较腰椎后路椎体间融合术(posterior lumbar interbody fusion,PLIF)和腰椎后外侧融合术(posterolateral lumbar fusion,PLF)治疗腰椎滑脱症患者手术前后及随访时影像学指标及临床疗效间的差异.方法 对2004年6月至2006年12月分别行上述两种手术治疗的113例腰椎滑脱症患者进行回顾性分析,PLIF组60例,PLF组53例.术前在腰椎侧佗X线片上测量椎间高度、滑脱率、节段角度、椎间孔面积等影像学指标,并采用Oswestry功能障碍指数(Oswestry disability index,ODI)、视觉模拟标尺(visual analogue scale,VAS)评分以及临床疗效主观评价表等指标对患者进行症状评分;术后即刻对卜述指标进行重复测量.并坚持随访,分别计算两组滑脱复位率和融合率.结果 两组平均手术时间及术中出血量分别为PLIF:(194.3±54.7)min.(402.2±123.9)ml;PLF:(179.3±45.7)min,(367.2±102.3)ml,差异均无统计学意义;术后PLIF组椎间高度、滑脱率、节段角度、椎间孔面积等影像学指标的恢复与维持均优于PLF组,末次随访时两组融合率分别为96.7%、88.6%(P=0.099);两组患者术后即刻及术后1年腰痛、腿痛VAS评分和Odl评分均较术前明显改善,临床疗效主观评价优秀率分别为56.7%(PLIF)与37.7%(PLF).结论 与PLF相比,PLIF对腰椎滑脱的矫正、椎间高度的维持、生理曲度的恢复以及椎间孔面积的扩大等指标均有显著的优越性,其临床疗效主观评价优秀率亦高于PLF组.     

椎弓根螺钉复位固定加不同融合方式治疗腰椎滑脱症疗效比较

目的对比分析椎弓根螺钉复位固定后后外侧融合（PLF）与后路椎间融合（PLIF）治疗腰椎滑脱症的临床疗效,评价两种融合方式的优劣。方法54例腰椎滑脱症患者中复位固定后行PLF（PLF组）26例,复位固定后行PLIF（PLIF组）28例。比较两组的临床疗效（ODI评分）、X线检查结果（包括滑脱矫正、滑脱节段椎间隙高度改变、滑脱节段前突角改变及植骨融合情况）及并发症。结果患者均获随访,时间2—6（3．5±0．4）年。术后即刻X线检查结果两组差异无显著性（P〉0,05）;术后2年随访时,两组间临床疗效、植骨融合率、滑脱节段前突角改变情况及并发症发生率差异均无显著性（P〉0．05）,但在滑脱矫正及滑脱节段椎间隙高度的维持上PLIF组优于PLF组（P〈0．05）,且内固定失败率亦低于PLF组。结论椎弓根螺钉复位固定后PLF或PLIF均为治疗腰椎滑脱症的有效方法,但PLIF在对腰椎滑脱矫正的维持及结构的稳定上较PLF具有更好的力学性能。     

Posterior lumbar interbody fusion. Association between disability and psychological disturbance in noncompensation patients.

STUDY DESIGN: An observational study of the relation between disability and psychological distress in patients with no on-going compensation claim who underwent posterior lumbar interbody fusion for chronic low back pain. OBJECTIVES: To study the change in the relation between disability and psychological distress after surgical management for low back pain. SUMMARY OF BACKGROUND DATA: Patient-related factors such as an on-going compensation claim and patient psychology are thought to influence the outcome of low back pain management. METHODS: Of the 58 patients who underwent posterior lumbar interbody fusion for low back pain between 1990 and 1995, 53 were observed for a mean duration of 2.7 years after surgery. Oswestry Disability scores and Distress and Risk Assessment Method scores were collected before surgery and at the follow-up examination. RESULTS: Improvement of 10 points on the Oswestry Disability Score was observed in 52.8% of the patients. However, the results in patients who were distressed before surgery were similar to the results observed in healthy patients. The difference in the Oswestry Disability Scores was 3.1 (95% confidence intervals [-9.9, 16.2], P = 0.297). The change in Distress and Risk Assessment Method scores showed a significant relation to change in the Oswestry Disability Scores (P = 0.033). CONCLUSIONS: Postoperative improvement in disability was not found to be related to preoperative psychology as measured by the Distress and Risk Assessment Method score. Change in disability is significantly related to change in distress.     

Management of chronic disabling low back pain with 360 degrees fusion. Results from pain provocation test and concurrent posterior lumbar interbody fusion, posterolateral fusion, and pedicle screw instrumentation in patients with chronic disabling low back pain.

STUDY DESIGN: A follow-up study conducted by an independent observer was performed on the authors' first 29 consecutive patients treated with concurrent posterior lumbar interbody fusion, posterolateral fusion, and pedicle screw instrumentation, for whom at least 2 years had transpired since the operation. OBJECTIVE: To evaluate the results of concurrent instrumented posterior lumbar interbody fusion and posterolateral fusion used to manage chronic disabling low back pain. SUMMARY OF BACKGROUND DATA: Patients chosen for surgery all had a history of chronic disabling low back pain exceeding 2 years and a sick leave period in excess of 6 months (average, 3.4 years). METHODS: From 1989 to 1993, 29 consecutive patients were surgically treated with fusion. The level of fusion was chosen depending on radiologic changes and results from a intradiscal injection provocation test. Bone union was verified by computed tomography scan with 1-mm-thin slices and sagittal reformation, and by a "second look" in all but three patients. All patients were evaluated subsequently by an independent observer in November 1995, 4.7 years after surgery on the average. RESULTS: Bone fusion was obtained in 27 of the 29 patients (93%). There was a highly significant reduction in back and leg pain measurements. Of the 29 patients, the results were excellent in 9 patients (31%), good in 6 patients (21%), fair in 6 patients (21%), and poor in 8 patients (27%). A total of 18 patients (62%) had returned to work. CONCLUSION: The authors consider posterior lumbar interbody fusion with concurrent posterolateral fusion and pedicle screw instrumentation a possible method for managing chronic disabling low back pain.     

退行性腰椎滑脱后路手术临床分析

目的 探讨退行性腰椎滑脱的后路手术治疗,比较后路腰椎管减压内固定并后外侧植骨及椎体间联合后外侧植骨术的临床疗效.方法 37例退行性腰椎滑脱患者采用后路减压、后外侧植骨内固定(A组21例)和椎体间联合后外侧植骨内固定(B组16例)手术,对两组术后植骨融合率及临床症状改善情况进行分析比较.根据术前、术后X线片和JOA评分评价植骨融合率及临床症状改善程度.结果 平均随访42个月.A组骨融合率为86%,B组为94%,两组无显著性差异.A组JOA评分优良率为90%,B组为94%,两组无显著性差异.结论 后路后外侧植骨内固定和椎间联合后外侧植骨内固定术均是有效的手术方法,但椎间联合后外侧植骨融合术的骨融合率较高.     

The influence of lumbar lordosis on spinal fusion and functional outcome after posterolateral spinal fusion with and without pedicle screw instrumentation

The aim of the current study was to examine the correlation between lumbar lordosis, spinal fusion, and functional outcome in patients suffering from severe low back pain, treated by posterolateral spinal fusion with or without pedicle screw instrumentation. One hundred thirty patients were randomly allocated to posterolateral lumbar fusion with or without Cotrel-Dubousset instrumentation. Functional outcome was assessed preoperatively, and 1 and 2 years postoperatively. Lordosis angles of the lumbar spine and fusion rates were assessed at the 1- and 2-year follow-up. No difference in lordosis angle was found between the two groups at any time. Lordosis was unchanged at 2 years compared with preoperative status in both groups. In the instrumented group, nonunion (23%) was followed by a decrease in lordosis at follow-up (p < 0.05). However, in the noninstrumented group, nonunion (14%) resulted in increased lordosis (p < 0.05). No correlation was found between functional outcome and lordosis angle. The current study showed no correlation between functional outcome and lordosis angle either before or after posterolateral spinal fusion. Use of instrumentation did not influence lumbar spinal alignment compared with noninstrumented fusions. The sagittal alignment was stable both 1 and 2 years after solid fusion. The failure mode of instrumented fusions was a reduced degree of lordosis in contrast to an increased degree of lordosis in patients with noninstrumented fusion.     

The Steffee variable screw placement system using different methods of bone grafting.

Two groups of patients with diseased lumbar spines treated by the Steffee variable screw placement system were studied, in order to compare concomitant posterolateral fusion and posterior lumbar interbody fusion. The use of posterolateral fusion resulted in less invasiveness than posterior lumbar interbody fusion, with regard to operating time and blood loss. With the posterolateral fusion method, correction of olisthesis or kyphotic deformity, if attained at all, was difficult to maintain. Posterior lumbar interbody fusion produced better correction and maintenance, even in osteoporotic cases. Bone union was achieved at an average of 11 months in only 60% of the posterolateral fusion group, whereas it was complete within a significantly shorter period (average; 6 months) in 91% of the posterior lumbar interbody fusion group. Breakage or loosening of screws occurred in 14% of the posterolateral fusion group. Deep wound infection and adhesive arachnoiditis, which were never seen in the posterolateral fusion group, developed in 3% of the posterior lumbar interbody fusion group. Posterior lumbar interbody fusion is considered to be a better method of bone grafting than posterolateral fusion, when used with the Steffee variable screw placement system.     

Fusion assessment of posterior lumbar interbody fusion using radiolucent cages: X-ray films and helical computed tomography scans compared with surgical exploration of fusion

BACKGROUND: Plain radiographic assessment of posterolateral fusion has been reported as accurate in only two thirds of patients who were found to be healed at surgical exploration. Plain radiographic techniques for fusion assessment of interbody fusion with radiolucent cages are reported to be accurate. A helical computed tomography (CT) scan shows a high sensitivity for pseudarthrosis compared with plain radiography. PURPOSE: To determine the accuracy of fusion assessment with plain X-ray films and helical CT scans by comparison to results of surgical exploration of fusion. STUDY DESIGN/SETTING: The accuracy and interobserver agreement of plain X-ray films and thin-cut helical CT scans were compared with fusion assessment by surgical exploration in patients with posterior lumbar interbody fusion using a radiolucent carbon fiber reinforced polymer cage (CFRP) and iliac crest bone graft. PATIENT SAMPLE: A review of 90 patients who had surgical exploration of the lumbar fusion. OUTCOME MEASURES: All patients had plain X-ray films including Ferguson anteroposterior parallel to the interbody space. Fifty-four patients had thin-section helical CT scans. METHODS: Fusion assessment by exploration was compared with blinded assessment by plain X-ray films and CT scans. RESULTS: Ninety patients had surgical exploration of 172 lumbar interbody and posterolateral fusion levels. At the time of exploration, fusion was determined to be successful in 87 of 90 patients and 168 of 172 (97%) fusion levels. X-ray assessment showed healed interbody fusions in 87% and posterolateral fusion healed in 75%. CT grading of the interbody fusion found healed interbody fusion in 77%, and the posterolateral fusion was fused in 68%. Plain X-ray films and CT scans had a sensitivity of 100% for pseudarthrosis and a negative predictive value of 100% for healed fusion. Specificity was almost 90% and was not significantly different between X-ray films and CT scans. CONCLUSIONS: Fusion assessment with plain X-ray films and helical CT scans showed equal accuracy after posterior lumbar interbody fusion confirmed by surgical exploration. Our results indicate that when plain X-ray films show strong evidence of fusion or pseudarthrosis, the helical CT is unlikely to provide useful new information.     

Single-level lumbar spine fusion: a comparison of anterior and posterior approaches

This study is a retrospective review of 122 patients who underwent single-level lumbar spine fusion. The objectives were to directly compare perioperative morbidity and early results of single-level anterior interbody posterolateral intertransverse process lumbar spine fusion and to provide objective findings that may be useful in selecting surgical method. Lumbar spinal fusion is a well-recognized surgical treatment of intractable low back pain resulting from DDD or spondylolisthesis. Assessments of techniques, results, and outcomes have been published, but detailed head-to-head comparisons of anterior posterior approaches with objective operative and postoperative data are not available in the literature. A retrospective review of 122 patients who underwent either an anterior interbody or posterolateral intertransverse process (average follow-up 22 and 26 months, respectively) single-level instrumented lumbar spinal fusion was performed. Surgical, perioperative, and follow-up data were obtained directly from medical records. The findings compared included estimated blood loss, need for blood transfusion, number of units transfused, operative time, number of days in hospital, need for transitional facility care, complications, need for further surgery, radiographic fusion, and clinical results. There was significantly less blood loss, need for transfusion, amount of blood transfused, operative time, and hospital stay for patients with anterior fusion procedures (p < 0.01). There was no significant difference in need for transitional facility care, complication rates, and given follow-up period in radiographic fusion rate and clinical outcome. Clinical results were significantly worse for those undergoing revision primary fusion (p < 0.01). The anterior approach to single-level lumbar fusion is associated with less morbidity than the posterolateral approach. This may in turn affect surgical outcome and hospital cost. However, both approaches to single-level lumbar fusion produce similar early fusion rates and clinical results. Revision fusions had poor early results regardless of approach.     

单侧椎弓根螺钉固定椎体间融合治疗腰椎退行性疾病

目的 探讨单侧椎弓根螺钉固定经椎间孔椎体间融合(transforaminal lumbar interbody fusion,TLIF)联合后外侧融合(posterolateral fusion,PLF)技术治疗腰椎退行性疾病的可行性及有效性.方法 分析2006年12月至2008年8月收治的因患腰椎退行性疾病行腰椎后路融合术并获得随访的患者78例.采用单侧椎弓根螺钉固定TLIF联合PLF技术治疗48例(单侧组),男25例,女23例;年龄31～64岁,平均47.6岁.采用双侧椎弓根螺钉固定TLIF联合PLF技术治疗30例(双侧组),男21例,女9例;年龄26～66岁,平均50.5岁.使用Oswestry功能障碍指数,疼痛视觉模拟评分(visual analogue score,VAS)评估两组患者术后疗效,并比较两组患者手术时间、出血量、融合率和椎间隙塌陷率等指标.结果 两组患者的Oswestry功能障碍指数、腰痛VAS评分、腿痛VAS评分在术前与术后3个月以及术后3个月与术后1年之间比较差异均有统计学意义,在术前与术后1年的评分改善方面差值比较无统计学意义.两组患者手术时间、出血量及住院费用比较差异均有统计学意义,单侧组少于双侧组.两组患者术后住院时间比较差异无统计学意义.单、双侧组融合率分别为91.7%(44/48)和93.3%(28/30).结论 椎间植骨联合单侧椎弓根螺钉固定能提供较好的脊柱即刻稳定性.单侧椎弓根固定TLIF联合PLF技术作为一种治疗腰椎退行性疾病的方法,疗效满意.     

The long-term effect of posterolateral fusion in adult isthmic spondylolisthesis: a randomized controlled study.

BACKGROUND: Today there is some evidence-based medicine support for a positive short-term treatment effect of fusion in chronic low back pain in spondylolisthesis and in nonspecific degenerative lumbar spine disorders. The long-term effect is, however, unknown. PURPOSE: To determine the long-term outcome of lumbar fusion in adult isthmic spondylolisthesis. STUDY DESIGN: Prospective, randomized controlled study comparing a 1-year exercise program with instrumented and non-instrumented posterolateral fusion with average long-term follow-up of 9 years (range, 5-13). PATIENT SAMPLE: 111 patients aged 18 to 55 years with adult lumbar isthmic spondylolisthesis at L5 or L4 level of all degrees, and at least 1-year's duration of severe lumbar pain with or without sciatica. OUTCOME MEASURES: Pain and functional disability was quantified by pain (VAS), the Disability Rating Index (DRI), the Oswestry Disability Index (ODI) work status, and global assessment of outcome by the patient into much better, better, unchanged or worse. Quality of life was assessed by the SF-36. METHODS: The patients were randomly allocated to treatment with 1) a 1-year exercise program (n=34), 2) posterolateral fusion without pedicle screw instrumentation (n=37), or 3) posterolateral fusion with pedicle screw instrumentation (n=40). Long-term follow-up was obtained in 101 (91%) patients. Nine patients in the exercise group were eventually operated on. RESULTS: Longitudinal analysis: At long-term follow-up pain and functional disability were significantly better than before treatment in both surgical groups. No significant differences were observed between instrumented and non-instrumented patients in any variable studied. In the exercise group the pain was significantly reduced but not the functional disability. Compared with the 2-year follow-up a significant increase in functional disability was observed, as measured by the DRI, but not the ODI, in the surgical group at long term. In the exercise group no significant changes were observed between the 2-year and the long-term follow-up. Cross-sectional analysis: Between the surgical and conservative group no significant differences were observed in any outcome measurement at long-term follow-up except for global assessment, which was significantly better for surgical patients. Of surgical patients 76% classified the overall outcome as much better or better compared with 50% of conservatively treated patients (p=0.015). Quality of life as estimated by the SF-36 at long term was not different between treatment groups in any of the eight domains studied but was considerably lower than for the normal population. CONCLUSIONS: Posterolateral fusion in adult lumbar isthmic spondylolisthesis results ina modestly improved long-term outcome compared with a 1-year exercise program. Although the results show that some of the previously reported short-term improvement is lost at long term, patients with fusion still classify their global outcome as clearly better than conservatively treated patients. Furthermore, because the long-term outcome of the patients conservatively treated most likely reflects the natural course, one can also conclude that no considerable spontaneous improvement should be expected over time in adult patients with symptomatic isthmic spondylolisthesis. Substantial pain, functional disability and a reduced quality of life will in most patients most likely remain unaltered over many years.     

Anterior lumbar interbody fusion: Does stable anterior fixation matter?

The purpose of this study was to compare the outcome of anterior lumbar interbody fusion without instrumentation (uninstrumented ALIF) against that with stable anterior cage fixation using Hartshill horseshoe instrumentation (ALIF-HH) for similar severity of disc disease. Between April 1994 and June 1998 the senior author N.R.B. performed 29 instrumented ALIF procedures with a Hartshill horseshoe cage (ALIF-HH). Between 1990 and 1998, the other senior author (J.M.H.), together with another senior consultant orthopaedic surgeon, performed 27 noninstrumented ALIF procedures using corticocancellous iliac crest autograft. All the patients in both groups had single-level fusion. An independent assessor (S.M.) performed the entire review. The mean follow-up was 4.7 years (2.3-7.9 years) in the uninstrumented ALIF group and 3.0 years (2.1-4.4 years) in the ALIF-HH group. There was subsidence of graft in four patients in the uninstrumented ALIF group. It is reasonable to assume that there was no pseudarthrosis in the ALIF-HH group. This difference was statistically significant (two-sided P-value =0.0425). On subjective score assessment, there was a satisfactory outcome (score0.05). On classification by the Oswestry Index into four categories, we found no difference in outcome between the two groups: 83.3% ( n=20) had a satisfactory outcome (defined as Excellent or Better) with ALIF and 77.8% ( n=21) had a satisfactory outcome with ALIF-HH using the Oswestry Disability Index for post-operative assessment ( P>0.05). The results of this study indicate that the Hartshill horseshoe cage does improve the fusion rate, but does not affect clinical outcome.     

Treatment of postdiscectomy low back pain by percutaneous posterior lumbar interbody fusion versus open posterior lumbar fusion with pedicle screws

BACKGROUND CONTEXT: Up to a fifth of the patients who had discectomy undergo spinal fusion because of disabling low back pain. PURPOSE: To compare the clinical outcome of percutaneous posterior lumbar interbody fusion (PPLIF) to that of open posterior lumbar fusion (PLF). STUDY DESIGN/SETTING: Two surgical methods that were tried in sequence at a university affiliated hospital. PATIENT SAMPLE: Sixty patients with disabling postdiscectomy low back pain. OUTCOME MEASURES: Pain intensity was scored on a visual analog scale (VAS) and the degree of disability was scored by the Oswestry disability index (ODI). METHODS: Thirty patients were treated by PPLIF. The outcome, after 24 months or more, was compared retrospectively with that of 30 consecutive suitable subjects who had been treated by PLF with pedicle screw fixation by the same surgeons for the same indication. RESULTS: In the PPLIF group, as compared with PLF group, mean operating time was shorter, blood loss was negligible, and mean hospital time was halved. By the last follow-up visit (greater than or equal to 2 years), pain and disability in PLF group had diminished by 31.9% and 20.1%, respectively. The corresponding figures in PPLIF group were 55.4% and 42.7%, respectively. CONCLUSIONS: In the context of postdiscectomy low back pain, PPLIF has proven, thus far, to be a safe procedure with improved clinical results.