Short‐term clinical observation of the Dynesys neutralization system for the treatment of degenerative disease of the lumbar vertebrae

Objective: To explore the safety and short‐term efficacy of the posterior approach of the Dynesys dynamic neutralization system for degenerative disease of the lumbar vertebrae. Methods: From March 2008 to March 2010, 32 cases of degenerative lumbar vertebral disease, 19 men and 13 women, (mean age 58 ± 5.2, range, 43–78 years), were treated with posterior laminectomy and Dynesys internal fixation. All patients had a history of over 3 months waist or leg pain that had not been relieved by conservative treatment. There were 10 cases of single lumbar intervertebral disc protrusion, 14 of degenerative lumbar spinal stenosis, 5 of degenerative lumbar isthmic spondylolisthesis, and 3 of recurrent lumbar disc protrusion after surgery. A visual analogue score (VAS) was used for pain assessment, and the Oswestry disability index (ODI) for functional evaluation of clinical outcomes. Results: All patients were followed up for 6–23 months (mean, 16.4 ± 5.5 months). Forty‐one segments in 32 patients were stabilized; 23 cases (71.9%) underwent single‐segmental stabilization, and 9 (28.1%) two‐segmental stabilization. VAS of leg pain, root and low back pain was significantly improved postoperatively. The ODI improved from preoperative 69% ± 12.6% to postoperative 28% ± 15.7% (P < 0.001). On the stabilized segment and adjacent segments above and below, the range of movement showed no statistical difference; no loosening of screws, cord and polyester spacer occurred. Conclusion: The Dynesys dynamic neutralization system combined with decompression can achieve satisfactory short‐term clinical results in lumbar degenerative disease. This procedure system not only reduces back and leg pain, but also preserves the mobility of fixed segments, minimizes tissue injury and avoids taking bone for spinal fusion.     

Dynamic Stabilization for Degenerative Spondylolisthesis and Lumbar Spinal Instability

Lumbar interbody fusion is a widely accepted surgical procedure for patients with lumbar degenerative spondylolisthesis and lumbar spinal instability in the active age group. However, in elderly patients, it is often questionable whether it is truly necessary to construct rigid fixation for a short period of time. In recent years, we have been occasionally performing posterior dynamic stabilization in elderly patients with such lumbar disorders. Posterior dynamic stabilization was performed in 12 patients (6 women, 70.9 ± 5.6 years old at the time of operation) with lumbar degenerative spondylolisthesis in whom % slip was less than 20% or instability associated with lumbar disc herniation between March 2011 and March 2013. Movement occurs through the connector linked to the pedicle screw. In practice, 9 pairs of D connector system where the rod moves in the perpendicular direction alone and 8 pairs of Dynamic connector system where the connector linked to the pedicle screw rotates in the sagittal direction were installed. The observation period was 77–479 days, and the mean recovery rate of lumbar Japanese Orthopedic Association (JOA) score was 65.6 ± 20.8%. There was progression of slippage due to slight loosening in a case with lumbar degenerative spondylolisthesis, but this did not lead to exacerbation of the symptoms. Although follow-up was short, there were no symptomatic adjacent vertebral and disc disorders during this period. Posterior dynamic stabilization may diminish the development of adjacent vertebral or disc disorders due to lumbar interbody fusion, especially in elderly patients, and it may be a useful procedure that facilitates decompression and ensures a certain degree of spinal stabilization.     

Results of surgery for spinal stenosis adjacent to previous lumbar fusion

The literature provides little data to guide surgical management of spinal stenosis adjacent to previous lumbar fusion. Thirty-three consecutive patients who had surgical decompression for spinal stenosis at the lumbar segments adjacent to a previous lumbar fusion were studied. The mean interval between fusion and the adjacent segment surgery was 94 months. Of the 33 patients, 26 were followed for 3-14 years (mean: 5 years) after adjacent segment surgery and were clinically evaluated and independently completed an outcome questionnaire. Of the 26 patients, 15 rated their outcome as completely satisfactory, 6 were neutral toward the surgery, and 5 considered their surgery a failure. The surgery was generally effective at improving or relieving lower extremity neurogenic claudication. The strongest independent predictive factor of patient dissatisfaction was ongoing postoperative low back pain (r = 0.7, p = 0.001). A higher back pain score at follow-up was associated with continued narcotic use (p = 0.001) and decreased ability to perform activities of daily living (p = 0.05). Six patients required further lumbar surgery during the follow-up period. This study provides the longest published follow-up data of surgical results for symptomatic spinal stenosis adjacent to a previously asymptomatic lumbar fusion.     

Wallis棘突间动态稳定系统对缓解腰椎融合术后邻近节段退变的临床疗效分析

目的：在行腰椎管减压融合的手术中,置入Wallis棘突间稳定系统,分析其缓解邻近节段腰椎退变的疗效。方法：自2007年7月至2009年7月,采用腰椎后路减压融合内固定术治疗腰椎退变性疾病患者40例（男16例,女24例,年龄25-60岁）,其中20例患者行腰椎后路减压融合内固定术的同时于具有退变趋势的邻近节段置入棘突间稳定系统Wallis固定（试验组）,其余20例单纯行腰椎后路减压融合内固定术（对照组）。分别于置入后1个月、3年对两组患者进行术后的JOA评分和目测类比评分（VAS）,同时测量并计算两组患者手术前后邻近节段椎间隙高度和椎管面积的变化情况。结果：40例患者均获得随访,时间3~5年,平均3．6年。40侧患者伤口均I类甲级愈合,术后疼痛情况均较术前缓解。两组患者置入后1个月JOA及VAS评分比较差异无统计学意义（P〉0．05）;术后3年JOA及VAS评分比较差异有统计学意义（P〈0。05）。两组患者术后1个月邻近节段椎间隙高度、椎管面积变化比较差异无统计学意义（尸〉0．05）;术后3年邻近节段椎间隙高度、椎管面积变化比较差异有统计学意义（R0．05）。结论：两种术式即刻效果无差异,均能取得良好的效果,此效果主要依赖于手术有效的减压。试验组中期效果明显优于对照组,主要是棘突间稳定系统Wallis发挥良好的生物学作用,有效减缓了因腰椎融合术导致的邻近节段的加速退变。     

Wirbelsäule: Implantate und Revisionen

Non-fusion spinal implants are designed to reduce the commonly occurring risks and complications of spinal fusion surgery, e.g. long duration of surgery, high blood loss, screw loosening and adjacent segment disease, by dynamic or movement preserving approaches. This principle could be shown for interspinous spacers, cervical and lumbar total disc replacement and dynamic stabilization; however, due to the continuing high rate of revision surgery, the indications for surgery require as much attention and evidence as comparative data on the surgical technique itself.     

Stabilization of the lumbar spine using the dynamic neutralization system

The records of 68 patients (42 men and 26 women) who underwent spine stabilization with a dynamic neutralization system were reviewed. Mean patient age at operation was 42.8 years. The primary indication for surgery was degenerative spine disease and instability with neurogenic or radicular pain and/or chronic back pain. Forty-one (60.2%) patients had degenerative diskopathy or disk herniation, and 27 (39.8%) patients had lumbar spine stenosis. One-motion segment spine stabilization was performed in 30 patients, 2-motion segment spine stabilization in 32 patients, and 3-motion segment spine stabilization in 6 patients. Within a mean follow-up of 36.2 months (range, 12.9-75.3 months), there were 2 re-operations, and 3 patients with screw loosening. Re-operations were for a deep infection in 1 patient and left leg pain in another patient. Both patients were managed with early implant removal and spinal arthrodesis. Self-assessment questionnaires showed improvement of patients' clinical and functional status. The Oswestry Disability Index and the Roland-Morris Disability Questionnaire score improved from a mean preoperative score of 55.4% (severe disability) and 52% respectively to a mean postoperative score of 22.9% (moderate disability) and 35% respectively. The overall results of this study are highly comparable to fusion procedures. The dynamic neutralization system can be a safe and effective alternative technique to spine arthrodesis in selected cases of degenerative lumbar spine instability.     

Kinematic evaluation of the adjacent segments after lumbar instrumented surgery: a comparison between rigid fusion and dynamic non-fusion stabilization

The aim of the current study was to evaluate changes in lumbar kinematics after lumbar monosegmental instrumented surgery with rigid fusion and dynamic non-fusion stabilization. A total of 77 lumbar spinal stenosis patients with L4 degenerative spondylolisthesis underwent L4–5 monosegmental posterior instrumented surgery. Of these, 36 patients were treated with rigid fusion (transforaminal lumbar interbody fusion) and 41 with dynamic stabilization [segmental spinal correction system (SSCS)]. Lumbar kinematics was evaluated with functional radiographs preoperatively and at final follow-up postoperatively. We defined the contribution of each segmental mobility to the total lumbar mobility as the percent segmental mobility [(sagittal angular motion of each segment in degrees)/(total sagittal angular motion in degrees) × 100]. Magnetic resonance imaging was performed on all patients preoperatively and at final follow-up postoperatively. The discs were classified into five grades based on the previously reported system. We defined the progress of disc degeneration as (grade at final follow-up) − (grade at preoperatively). No significant kinematical differences were shown at any of the lumbar segments preoperatively; however, significant differences were observed at the L2–3, L4–5, and L5–S1 segments postoperatively between the groups. At final follow-up, all of the lumbar segments with rigid fusion demonstrated significantly greater disc degeneration than those with dynamic stabilization. Our results suggest that the SSCS preserved 14% of the kinematical operations at the instrumented segment. The SSCS may prevent excessive effects on adjacent segmental kinematics and may prevent the incidence of adjacent segment disorder.     

Unilateral transforaminal posterior lumbar interbody fusion.

A prospective analysis of consecutive patients who had lumbar fusion using the unilateral transforaminal posterior lumbar interbody fusion with pedicle screw fixation is presented to assess the clinical and radiographic outcomes of the transforaminal posterior lumbar interbody fusion procedure and describe the technique and indication in the treatment of degenerative disease of the lumbar spine. Forty patients treated with transforaminal posterior lumbar interbody fusion for degenerative diseases of the lumbar spine (with anterior column deficiency) were followed up for a minimum of 3 years (mean, 3.4 years; range, 3-3.9 years). Radiographic assessment included plain and flexion and extension radiographs. Clinical outcome was based on pain relief, ability to do activities of daily living, and return to work. Thirty-six patients (90%) had solid fusions and at latest followup, segmental lordosis has increased in all patients. Eighty-five percent of patients had excellent or good clinical outcome(s). The unilateral transforaminal posterior lumbar interbody fusion provides bilateral anterior column support through a unilateral approach. The patients had high fusion rates and patient satisfaction as reported with similar complications found in other methods commonly used for spinal decompression and stabilization.     

Spontaneous effect of increased stability of the lower lumbar spine in cases of severe chronic back pain. The answer of an external transpeduncular fixation test

Eighteen patients with severe low-back pain of long duration were externally stabilized over selected segments of the lumbar spine to evaluate the pain relieving effect of increased stability. Five millimeter Schantz screws were driven into the vertebral body transpeduncularly by a closed technique using an image intensifier. A modified Hoffmann fixation device with possibilities to compress and distract was used for external stabilization. The results were recorded by means of pain area sketches and pain lines. All but one patient experienced remarkable relief of low-back pain and often of pain radiating into the lower extremities. No serious complications were seen. Of eight patients with residual severe pain after fusions, five were considered healed using radiologic techniques and three were improved by external stabilization. This test could be used to identify candidates, select levels for lumbar fusion, and evaluate the stability of previous fusions.     

下腰椎内固定融合手术后复发性腰痛及下肢放射痛23例原因分析

目的分析椎弓根螺钉内固定下腰椎融合手术后腰痛原因。方法随访2001年1月~2003年12月采用椎弓根螺钉内固定下腰椎融合手术103例,男43例,女60例;腰椎滑脱28例,腰椎管狭窄54例,腰椎间盘突出症21例。随访时进行问卷调查及X线、CT或MRI检查,并分析手术后腰痛的可能原因。结果随访时间3~5年,疗效优良80例(77.7%);术后有明显腰痛或腰痛伴下肢放射痛23例(22.3%)。邻近节段疾病11例(2节段融合7例,1节段融合4例;10.7%),内固定使用不当3例,椎弓根螺钉断裂2例,减压不完全2例,高位椎间盘突出1例,不明原因4例。结论邻近节段疾病、内固定使用不当、内固定失败是复发性腰痛主要原因。原有退变基础、减压范围超过融合节段、融合节段的长短都是产生邻近节段疾病的重要的危险因素。     

腰椎融合辅以邻近节段动态固定治疗腰椎退行性疾病的早期临床疗效观察

目的 评价腰椎融合辅以邻近节段K-Rod动态固定治疗腰椎退行性疾病的临床疗效及对腰椎运动功能的影响,探讨K-Rod动态固定对邻近节段保护的优劣.方法 回顾性分析2010年4月~2011年9月采用椎间融合辅以邻近节段K-Rod 动态固定及单节段椎间植骨融合内固定术的51例患者.A组（K-Rod组）24例患者术前邻近节段存在退变,行单节段融合辅以邻近节段K-Rod动态固定;B组（单节段融合组）27例患者术前邻近节段无不稳或退变,行单节段椎间植骨融合内固定术.对比评价2组腰腿痛视觉模拟量表（visual analogue scale,VAS）评分、Oswestry 功能障碍指数（ Oswestry disability Index,ODI） 、椎间隙高度、腰椎总活动度（range of motion,ROM）及头侧邻近第一节段活动度（ROM1）、头侧邻近第二节段或尾侧第一邻近节段活动度（ROM2）、保护节段及邻近节段退变（adjacent segment degeneration,ASD）发生率.结果随访 24~37个月.2组患者术后VAS评分及ODI均显著改善,且2组间差异无统计学意义.2组间腰椎总ROM术前及末次随访之间均无差异.A组保护节段末次随访时椎间隙高度与术前无差异.2组ROM1及ROM2术前术后相比差异均有显著统计学意义,2组间相比差异无统计学意义.A组末次随访时8例患者出现11（11/138,8%）枚螺钉松动;B组无螺钉松动.结论 腰椎融合辅以邻近节段动态固定具有较好的临床疗效,增加的动态固定保护了术前已存在退变的节段,避免了多节段融合,降低了单节段融合邻椎病的风险,因此适应证选择合适,具有较好的临床应用价值.     

动态中和固定系统治疗腰椎退行性疾病的研究进展

动态固定技术治疗腰椎退行性疾病日益成为基础和临床研究的热点。动态中和固定系统(dynamic neutralization system,Dynesys)作为动态固定技术的一种,既能保持脊柱的活动能力,改善患者的临床症状,还在延缓邻近节段退变方面表现出一定的优势。Dynesys技术可作为腰椎融合之外治疗腰椎退行性疾病的另一最佳选择,主要适用于轻至中度的腰椎退变性疾病,但它缺乏保持和恢复腰椎前凸的机制需要患者主动伸展实现前凸。如何延长使用寿命、预防并发症发生等问题有待解决,其远期疗效及延缓邻近节段退变作用机制需进一步明确。     

Pedicle screw-based posterior dynamic stabilization in the lumbar spine

Traditionally, management of spinal pathology has centered on decompression, correction of deformity, and stabilization. Deformity correction and stabilization have been accomplished largely by spinal fusion at the pathologic levels. In addition to the risks and potential complications, there are sequelae to a successful fusion. Therefore, attention is being directed toward disk replacement in the lumbar spine. In addition to their preserving motion in the anterior column, several posterior motion-preservation devices have been developed in an effort to prevent pathologic motion at both a decompressed level and a segment adjacent to a fusion. Initial studies suggest that the results of posterior dynamic stabilization may be comparable to those of fusion; however, longer periods of clinical and radiographic follow-up are required to fully define the role these devices may play in the management of the degenerative lumbar spine.     

Dynamische Versorgung der Lendenwirbels?ule

Total disc replacement and posterior dynamic stabilization represent alternatives to lumbar spinal fusion which should reduce the risk of adjacent segment degeneration. Disc replacement is indicated for pure discopathy without facet joint degeneration. Spinopelvic balance influences the implant's biomechanics. Therefore pelvic incidence, sacral slope, segmental lordosis and the mean axis of rotation need to be considered. Dynamic stabilization is indicated in moderate discopathy and facet joint degeneration, in degenerative spondylolisthesis grade I with a hypermobile segment and in dynamic lumbar stenosis. The combination of caudal fusion and cranial dynamic stabilization allows a better maintenance of lordosis with multiple level instrumentation and prevents adjacent segment degeneration. If pelvic incidence and sacral slope are high, L5-S1 should be fused because of elevated shear forces.     

Problems of posterior lumbar interbody fusion (PLIF) for the rheumatoid spondylitis of the lumbar spine

We performed posterior lumbar interbody fusion (PLIF) on 7 patients with rheumatoid spondylitis (RA) of the lumbar spine with severe low-back pain and/or cauda equina symptoms, and evaluated the effectiveness of PLIF for the lumbar spinal instability in RA secondary to destruction of the anterior elements, including vertebral endplates and the apophyseal joint. The subjects were 7 patients with classic RA, 2 men and 5 women, mean age 65 years old, and the mean duration of RA was 21 years. All had severe low-back pain and difficulty with walking. According to the ARA classification, the patients were at stage 3 or worse and in class 3. Diagnostic imaging including magnetic resonance imaging (MRI), tomography, myelography, and computed tomographic myelography (CTM) of the lumbar spine clearly delineated pathology, destruction of the vertebral endplate, subluxation, and cauda compression which can be well treated with PLIF. We performed L4/5PLIF (5 cases), L3/4 and L4/5 PLIF (2 cases), and posterior fixation with instruments for anterior column repair and stabilization and posterior decompression. Autografts (all cases) and Brantigan IF cage (2 cases) were used. Stable fixation of the lumbar spine was achieved after surgery, and improvement in gait and activities of daily living were achieved through the relief of low-back pain and radicular pain; the mean duration of follow-up was 22 months. Postoperative, plain radiography, CT, and MRI revealed the enlargement of the lumbar canal and fusion and incorporation of grafted bone, but in some cases, collapse of graft, migration of pedicle screw, instability of adjacent level, and collapse of adjacent vertebra were noted. PLIF with spinal instruments is a preferred treatment for rheumatoid spondylitis of the lumbar spine, but in the mutilating type of RA with severe osteoporosis, PLIF in combination with a long fixation system and/or augmentation of the vertebral bodies might be needed.     

人工椎间盘在腰椎退行性疾病中的临床应用进展

腰椎间盘退行性疾病是脊柱外科常见疾病,也是成年人腰痛和伤残的主要原因之一。传统观念认为腰椎融合术的临床效果是肯定的,但没有保留脊柱的生理运动功能,并且腰椎运动节段的融合加快了邻近节段椎间盘及小关节的退变。腰椎功能解剖学和生物力学领域深入的研究使得不同构造和材质的现代人工椎间盘装置的发展成为可能。人工腰椎间盘置换术作为腰椎融合之外治疗腰椎退行性疾病的另一合理的选择,目的是使退变椎间盘引起的疼痛得到长期缓解,重建椎间隙高度以保护神经组织,保留脊柱运动以避免晚期关节突关节及邻近节段的病变,恢复脊柱的运动学和载荷特性。本综述旨在阐释人工腰椎间盘的类型,该领域中的研究及临床应用进展和发展前景。     

Reconstruction of the lumbar spine using AO DCP plate internal fixation

Augmentation of lumbar spine fusion with internal fixation using pedicle screw systems has gained wide currency because it offers rigid stabilization to foster fusion healing. The AO DCP plate has been employed in Europe as a spinal implant with pedicle fixation using 6.5 mm, full-threaded cancellous bone screws with success. This report details the experience of using this device for lumbar spine fusion in a series of 46 North American patients with a mean follow-up of 1.25 years (range 1-2.5 years). Thirty-one patients had had prior lumbar spine surgery with poor outcomes, and 15 had had no prior surgery. All were treated surgically for lumbar degenerative disease with canal decompression, internal fixation with AO plates, and fusion with autologous bone grafting posterolaterally. Complications included two early and one delayed wound infection; five cases of screw loosening; three cases of screw breakage; and three cases of screw impingement upon a nerve. Results of surgery in 17 patients with failed interbody fusion included good to excellent pain relief in 59%, and solid fusion in 76%. In 14 patients with failed posterior surgery the good to excellent pain relief rate was 79%, and the fusion rate was 86%. In 15 patients undergoing primary surgery there was 89% good to excellent pain relief and a solid fusion rate of 87%. The benefits accruing from augmentation of the fusion with internal fixation using AO DCP plates are positive and justify its continued use. Complications encountered in the early experience have been significantly reduced in subsequent series, indicating the existence of a "learning curve" effect which would mandate specific training of spinal surgeons in the technique.     

Long-term actuarial survivorship analysis of an interspinous stabilization system

In 1986, an interspinous dynamic stabilization system (the prototype of the current Wallis implant) was designed to stiffen unstable operated degenerate lumbar segments with a hard interspinous blocker to limit extension and a tension band around the spinous processes to secure the implant and limit flexion. Restoring physiological mechanical conditions to the treated level(s) while preserving some intervertebral mobility was intended to treat low-back pain related to degenerative instability without increasing stress forces in the adjacent segments. The procedure was easily reversible. If low back pain persisted or recurred, the device was removed and stability was achieved using fusion. The intermediate-term results were promising, but the long-term safety and efficacy of this dynamic interspinous stabilization device has not been previously documented. We retrospectively reviewed the hospital files of all the patients (n = 241) who had this dynamic stabilization system implanted between 1987 and 1995, contacting as many as possible to determine the actuarial survivorship of the system. In this manner, 142 of the 241 patients (58.9%) were contacted by telephone. The endpoints used for the survivorship analysis were 'any subsequent lumbar operation' and 'implant removal'. At 14 years follow-up, values of actuarial survivorship with 95% confidence interval were 75.9 +/- 8.3 and 81.3 +/- 6.8% for the endpoints 'any subsequent lumbar operation' and 'implant removal', respectively. There was no difference in survivorship of multiple-level implants with respect to single-level devices. Although the conclusions of the present study must be tempered by the 41% attrition rate, these findings support the long-term safety of this system, and possibly long-term protective action against adjacent-level degeneration by motion preservation. Outcomes at least equivalent to those of fusion were observed without the primary drawbacks of fusion.     

Surgical Results after Soft System Stabilization of the Lumbar Spine in Degenerative Disc Disease – Long Term Results

Summary  After having reported preliminary results of soft system stabilization according to Graf in a series of 27 patients with degenerative disc disease of the lumbar spine in early 1995 the authors report long term clinical and radiological results of this patient series (n=25). At a mean period of postoperative observation of 50 months excellent, good, satisfactory, moderate and poor results were obtained in 62,9%, 11,1% and 11,1%, 7,4% and 7,4 % of the patients, respectively. The well-known phenomenon of loss of disc height at the level of posterolateral fusion and instrumentation as well as overcharge of adjacent segments were not observed after soft system stabilization. Regional as well as global lumbar lordosis were maintained and, although statistically not significant, an increase of intervertebral distance was observed in adjacent segments in flexion of the lumbar spine. These phenomena might represent pressurization of instrumented as well as adjacent discs after the insertion of ligament prostheses. It is the impression of the authors, that the Graf technique leads to good surgical results in degenerative disc disease with destabilization of lumbar motion segment(s) if the following criteria are strictly respected: 1.*No or only mild arthrotic changes of the facet joints 2.*Preferably minor disc degeneration/only mild loss of intervertebral distance 3.*Well trained low back muscles and 4.*A clear-cut, repeatedly demonstrated pain-relief on trial anaesthesia of the corresponding articular nerves and while wearing a probatory jacket.     

Impact of instrumentation in lumbar spinal fusion in elderly patients

Background and purpose An increasing number of lumbar fusions are performed using allograft to avoid donor-site pain. In elderly patients, fusion potential is reduced and the patient may need supplementary stability to achieve a solid fusion if allograft is used. We investigated the effect of instrumentation in lumbar spinal fusion performed with fresh frozen allograft in elderly patients.Methods 94 patients, mean age 70 (60–88) years, who underwent posterolateral spinal fusion either non-instrumented (51 patients) or instrumented (43 patients) were followed for 2–7 years. Functional outcome was assessed with the Dallas pain questionnaire (DPQ), the low back pain rating scale pain index (LBPRS), and SF-36. Fusion was assessed using plain radiographs.Results Instrumented patients had statistically significantly better outcome scores in 6 of 7 parameters. Fusion rate was higher in the instrumented group (81% vs. 68%, p = 0.1). Solid fusion was associated with a better functional outcome at follow-up (significant in 2 of 7 parameters). 15 patients (6 in the non-instrumented group and 9 in the instrumented group) had repeated lumbar surgery after their initial fusion procedure. Functional outcome was poorer in the group with additional spine surgeries (significant in 4 of 7 parameters).Interpretation Superior outcomes after lumbar spinal fusion in elderly patients can be achieved by use of instrumentation in selected patients. Outcome was better in patients in which a solid fusion was obtained. Instrumentation was associated with a larger number of additional surgeries, which resulted in a lesser degree of improvement. Instrumentation should not be discarded just because of the age of the patient.