Rationale for spinal fusion in lumbar spinal stenosis

In order to define the indications for spinal fusion in patients undergoing decompression for lumbar spinal stenosis, 114 patients surgically treated were reviewed. Follow-up was 24 to 108 months. Patients were grouped into four categories: 15 with lateral recess stenosis, 45 with central-mixed stenosis, 43 with stenosis following prior lumbar surgery(s), and 11 with scoliosis and spinal stenosis. Only two patients with lateral recess stenosis underwent fusion with fair results. Approximately one-third of those with central-mixed stenosis required a fusion. Results were good in 70%. In those with stenosis following prior lumbar surgeries, although not statistically significant, those who had concomitant decompression and arthrodesis had a better outcome than those in whom decompression only was done. Patients with scoliosis and stenosis had decompression for significant motor and reflex deficits and fusion over the length of their major curves. Patients having decompression for lumbar stenosis with degenerative spondylolisthesis, isolated disc resorption with degenerative facet joints, intervertebral disc disease with instability, and those with scoliosis with multidirectional instabilities benefit from concomitant spinal fusion.     

Spinal canal enlargement procedure by restorative laminoplasty for the treatment of lumbar canal stenosis.

BACKGROUND CONTEXT: Multilevel fenestration or laminectomy is generally performed to treat the patient with lumbar canal stenosis (LCS). However, in patients requiring laminectomy, little attention has been paid to the later development of lumbar pain possibly caused by a removal of the posterior elements of the spine. In general, spinal instrumentation and fusion has been generally performed when laminectomy might cause severe postoperative spinal instability. Surgical methods where osteotomized vertebral arches are repositioned rather than removed have long been performed. However, they have never become widespread, possibly because of the complicated surgical procedures and poor postoperative arch stability, which leads to a long period of postoperative immobilization. PURPOSE: The purpose of the present report was to introduce our surgical procedures of spinal canal enlargement using restorative laminoplasty and to report the results. STUDY DESIGN/SETTING: This retrospective study was conducted to analyze the clinical results in 33 patients with lumbar canal stenosis who had been treated by our surgical procedures of spinal canal enlargement using restorative laminoplasty. PATIENT SAMPLE: Subjects were 33 patients followed for at least 2 years after surgery. Meyerding Grade I degenerative spondylolisthesis was found in 10 patients, and degenerative scoliosis of more than 5 degrees was seen in 20 patients. Nine patients demonstrated both degenerative spondylolisthesis and degenerative scoliosis. OUTCOME MEASURES: Using the Japanese Orthopedic Association (JOA) scoring system, lumbago, sciatica, leg numbness, muscle strength and gait were quantified before surgery, 1 year after surgery and at final examination (at least 2 years after surgery) to calculate improvement rates. Furthermore, correlations to age, gender, disease duration, degenerative spondylolisthesis and degenerative scoliosis were statistically analyzed. METHODS: Our surgical procedures of spinal canal enlargement using restorative laminoplasty were performed for all patients. In our procedures, posterior elements were reapplied with an absorbable fixation (poli-L-lactic acid pins). No other fusion procedure was performed jointly. RESULTS: The mean number of restored vertebral arches was 2.2, and mean surgery time was 131 minutes. Mean volume bleeding during surgery was 328.0 ml. In all patients, successful bone healing was obtained at a mean of 5 months after surgery. Mean improvement rate for the total JOA score was 80.6%. Mean improvement rates for lumbago and sciatica were 70.0% and 87.7%, respectively. Mean improvement rate for leg numbness was 50.8%. Mean improvement rates for leg muscle strength and intermittent claudication were 70.0% and 98.9%, respectively. No significant correlation was found between gender and overall improvement rate, between age and overall improvement rate, between age and leg numbness or between number of restored vertebral arches and overall improvement rate. The tendency was that the longer the disease duration, the lower the overall improvement rate, and the more severe the residual numbness. No significant correlation was found between disease duration and muscle strength or lumbago.A significant correlation was not found between the presence of preoperative Grade I degenerative spondylolisthesis and overall improvement rate or lumbago. However, a significant difference in severity of lumbago existed between patients with degenerative scoliosis of 9 degrees and below and those with degenerative scoliosis of 10 degrees and above. CONCLUSIONS: Our surgical procedures of spinal canal enlargement using restorative laminoplasty produce complete decompression and anatomical reconstruction of the posterior elements, ligaments and muscles. Improvement in complaints of lumbago may be a consequence of the anatomical reconstruction of the posterior spinal elements. Overall, favorable results were obtained. The best results were obtained if surgery is performed within 2 years of the onset of LCS.     

Decompression, fusion, and instrumentation surgery for complex lumbar spinal stenosis

Between 1990 and 1993, 54 consecutive patients were treated with decompression, fusion and instrumentation surgery for complex lumbar spinal stenosis. The mean age of the patients was 60 years. The average followup was 39 months. Clinically, there was one deep wound infection, and three mechanical failures. There were two staged operations. There were three revision surgeries performed for mechanical reasons. Of the 47 patients who completed the questionnaire, 96% of patients were very satisfied or somewhat satisfied with the operation, 98% were satisfied with relief of pain, 94% were satisfied with their ability to walk, 89% were satisfied with their strength, and 94% were satisfied with balance. Survivorship analysis (failure endpoint was revision surgery) revealed that at the end of 4 years, the patient had a 92% chance of not undergoing revision surgery for any reason (mechanical and infectious), and a 94% chance of not undergoing revision surgery for mechanical reasons. Lumbar decompression, fusion, and instrumentation surgery seems to be efficacious in patients with complex lumbar spinal stenosis (associated previous lumbar spine operations with evidence of radiographic instability, radiographic evidence of junctional stenosis after surgery, radiographic evidence of instability, degenerative spondylolisthesis greater than Grade I with instability, if present, and degenerative scoliosis with a curve greater than 20 degrees).     

Clinical outcome of microendoscopic posterior decompression for spinal stenosis associated with degenerative spondylolisthesis--minimum 2-year outcome of 37 patients

A clear consensus for the optimal surgical treatment for spinal stenosis associated with degenerative spondylolisthesis (DS) has not appeared. In general, decompression and fusion are recommended. However, the symptoms of spinal stenosis are the main complaints in almost all patients with DS, and whether or not routine concomitant fusion is necessary in the surgical treatment for DS is still discussed controversially. The authors have treated almost all the patients with spinal stenosis associated with DS by microendoscopic posterior decompression (MEPD) procedures since 2001. In the present study, we examined the minimum 2-year outcome in 37 patients surgically treated with the MEPD procedures for spinal stenosis associated with DS. At the mean of 38 months after surgery, the overall results were excellent in 54% of the patients, good in 19%, fair in 13.5%, and poor in 13.5%, based on the Japanese Orthopedic Association lumbar score, a visual analogue scale, and the Roland-Morris disability questionnaire. Although the progression of spondylolisthesis and the increase of segmental sagittal motion after surgery were seen in 7 patients (19%), only one patient required secondary fusion during the follow-up period. A sufficient decompression with the preservation of the posterior structures of the spine was observed in almost the patients after surgery. In conclusion, the MEPD is a minimally invasive procedure developing a sufficient decompression with the preservation of the spinal stability. Thus, the MEPD is one of the useful procedures in the surgical treatment of spinal stenosis associated with DS. However, further follow-up studies should be performed to evaluate the long-term outcome for evaluation of the true validity of the MEPD for DS.     

Lumbar spinal stenosis: surgical considerations

Spinal stenosis is an acquired or congenital narrowing of the spinal or nerve-root canals. Surgical treatment is often effective. Acquired spinal stenosis most commonly occurs in those with degenerative disk disease and arthritic facets. If the degenerative process stabilizes and there is adequate room to accommodate the neural contents, symptomatic patients become asymptomatic. Residual stability after decompression must be assessed in patients having multilevel decompression. Fusion maybe indicated. In women with osteoporosis coexisting with degenerative scoliosis and spinal stenosis, decompression for concave nerve-root compression and fusion are necessary. Spinal fusion is not indicated in patients with lumbar spinal stenosis having unilateral decompression for lateral stenosis. Patients with central-mixed stenosis may not need fusion. Patients with spinal stenosis after laminectomies and diskectomies had better results when arthrodesis was done in conjunction with repeated decompression. Arthrodesis with instrumentation and decompression is recommended for patients with degenerative spondylolisthesis.     

Decompression alone versus decompression with fusion in patients with lumbar spinal stenosis with degenerative spondylolisthesis: a systematic review and meta-analysis

Introduction

Surgical decompression is standard care in the treatment of degenerative spondylolisthesis in patients with symptomatic lumbar spinal stenosis, but there remains controversy over the benefits of adding fusion. The persistent lack of consensus on this matter and the availability of new data warrants a contemporary systematic review and meta-analysis of the literature.

Methods

Multiple online databases were systematically searched up to October 2022 for randomized controlled trials (RCTs) and prospective studies comparing outcomes of decompression alone versus decompression with fusion for lumbar spinal stenosis in patients with degenerative spondylolisthesis. Primary outcome was the Oswestry Disability Index. Secondary outcomes included leg and back pain, surgical outcomes, and radiological outcomes. Pooled effect estimates were calculated and presented as mean differences (MD) with their 95% confidence intervals (CI) at two-year follow-up.

Results

Of the identified 2403 studies, eventually five RCTs and two prospective studies were included. Overall, most studies had a low or unclear risk of selection bias and most studies were focused on low grade degenerative spondylolisthesis. All patient-reported outcomes showed low statistical heterogeneity. Overall, there was high-quality evidence suggesting no difference in functionality at two years of follow-up (MD − 0.31, 95% CI − 3.81 to 3.19). Furthermore, there was high-quality evidence of no difference in leg pain (MD − 1.79, 95% CI − 5.08 to 1.50) or back pain (MD − 2.54, 95% CI − 6.76 to 1.67) between patients undergoing decompression vs. decompression with fusion. Pooled surgical outcomes showed less blood loss after decompression only, shorter length of hospital stay, and a similar reoperation rate compared to decompression with fusion.

Conclusion

Based on the current literature, there is high-quality evidence of no difference in functionality after decompression alone compared to decompression with fusion in patients with degenerative lumbar spondylolisthesis at 2 years of follow-up. Further studies should focus on long-term comparative outcomes, health economic evaluations, and identifying those patients that may benefit more from decompression with fusion instead of decompression alone. This review was registered at Prospero (CRD42021291603).

     

Comparison of decompression,decompression plus fusion,and decompression plus stabilization: a long-term follow-up of a prospective,randomized study

BACKGROUND CONTEXTLumbar canal stenosis due to degenerative lumbar spondylolisthesis is one of the most common indications for lumbar spinal surgery. However, from a long-term perspective, it is still unclear which of these procedures should be performed: decompression, decompression plus fusion, or decompression plus stabilization.PURPOSEThis study aimed to present the long-term results of a randomized controlled trial of surgery for degenerative spondylolisthesis.STUDY DESIGN/SETTINGThis is a long-term follow-up of a previously reported randomized controlled trial.PATIENT SAMPLEPatients aged ≤75 years with single L4/5 level lumbar canal stenosis caused by degenerative lumbar spondylolisthesis were enrolled at two hospitals from May 1, 2003, to April 30, 2012; the final follow-up was on May 20, 2021.OUTCOME MEASURESThe following data were collected: modified Japanese Orthopedic Association (JOA) score, visual analog scale (VAS) score for lower back pain, leg pain, and numbness, and scores from eight Short-Form 36 (SF-36) subscales preoperatively, 1 year postoperatively, 5 years postoperatively, and at the final follow-up.METHODSPatients were randomized to undergo decompression alone, decompression plus fusion, or decompression plus stabilization. The primary outcome measure was the change in VAS for lower back pain with secondary outcomes including the modified JOA score, VAS for leg pain, VAS for leg numbness, eight SF-36 subscale scores, and occurrence of reoperation at the last follow-up.RESULTSAmong 85 patients who were randomized, 66 responded to the current survey. The mean follow-up period was 12.3 years. The VAS score for low back pain improvement was not significantly different between the decompression and fusion groups at the mean follow-up of 12.3 years. Of the 12 secondary outcomes, 8 showed no significant difference between decompression and fusion, 12 showed no significant difference between decompression and stabilization, and 10 showed no significant difference between fusion and stabilization.CONCLUSIONSAlthough additional instrumentation surgery did not significantly improve low back pain at the mean follow-up of 12.3 years compared with decompression alone, fusion surgery provided clinically meaningful improvements in patient-reported vitality, social functioning, role limitations due to personal or emotional problems, and mental health compared with decompression alone.TRIAL REGISTRATIONUMIN000028114     

腰椎退变性侧凸的治疗策略

目的探讨非手术治疗或腰椎后路减压、矫形固定、融合手术治疗由于椎间盘退变后继发小关节退变、椎管和神经根管容积变化以及脊柱失稳、畸形等病理改变导致的腰椎退变性侧凸患者的效果。方法2001年7月-2007年6月，治疗退变性腰椎侧凸患者56例，其中行非手术治疗5例。手术治疗51例。手术组患者平均年龄为63岁，腰椎侧凸Cobb角平均30°，采用腰椎后路减压，或辅助椎弓根螺钉矫形固定、后外侧融合或椎间融合治疗。结果56例均得到随访，平均随访时间为20个月，非手术治疗和手术患者均对治疗效果满意，生活质量提高，手术组矫正角度平均为15°，骨融合率达到95％，无神经损伤及翻修病例。结论腰椎退变性侧凸首选非手术治疗，如失败应根据患者情况遵循尽量采用有限内固定和融合的原则行手术治疗。     

Lumbar spinal stenosis. Treatment strategies and indications for surgery

Initially, all patients with degenerative lumbar spinal stenosis should be treated conservatively. Rapid deterioration is unlikely. The majority of patients may either improve or remain stable over a long-term follow-up with nonoperative treatment. Surgery should be an elective decision by the patients who fail to improve after conservative treatment. Medical evaluation is mandatory in those elderly patients with frequent comorbidities. For central spinal stenosis, without significant grade I spondylolisthesis or deformity, decompression is the surgical treatment of choice. Iatrogenic instability must be avoided during decompression surgery by preserving the facet joint and the pars interarticularis. Limited decompression with laminotomy may be indicated for lateral canal stenosis. A limited decompression may avoid postoperative instability but is associated with more frequent neurologic sequelae. Postlaminectomy instability is uncommon, and too little decompression is a more frequent mistake than too much. Decompression is usually associated with good or excellent outcome in 80% of patients. Deterioration of initial post-operative improvement may occur over long-term follow-up. When spinal stenosis is associated with instability, degenerative spondylolisthesis, deformity, postoperative instability, or recurrent stenosis, fusion is often recommended. Instrumentation often improves the fusion rate but does not influence the clinical outcome. Generous decompression but selective fusion of the unstable segment only are preferable for degenerative spondylolisthesis and type I degenerative scoliosis with minimal rotation of the spine.     

The impact of the Spine Patient Outcomes Research Trial (SPORT) results on orthopaedic practice

The benefits of spinal surgery for relief of low back and leg pain in patients with degenerative spinal disorders have long been debated. The Spine Patient Outcomes Research Trial (SPORT) was designed to address the need for high-quality, prospectively collected data in support of such interventions. SPORT was intended to provide an evidential basis for spinal surgery in appropriate patients, as well as comparative and cost-effectiveness data. The trial studied the outcomes of the surgical and nonsurgical management of three conditions: intervertebral disk herniation, degenerative spondylolisthesis, and lumbar spinal stenosis. Both surgical and nonsurgical care of intervertebral disk herniation resulted in significant improvement in symptoms of low back and leg pain. Still, the treatment effect of surgery for intervertebral disk herniation was less than that seen in patients who underwent surgical versus nonsurgical treatment of degenerative spondylolisthesis and lumbar spinal stenosis. Across SPORT, more significant degrees of improvement with surgery were noted in chronic conditions of lumbar spinal stenosis and lumbar spinal stenosis with spondylolisthesis. In addition, no catastrophic progressions to neurologic deficit occurred as a result of watchful waiting.     

Predictors of outcomes after posterior decompression and fusion in degenerative spondylolisthesis

No consensus has been reached regarding surgical management of degenerative spondylolisthesis. The optimal type of surgical procedure and surgical indications have not been precisely defined. In order to screen for predictors of outcome, we retrospectively studied patient outcomes after posterior decompression and fusion for isolated lumbar degenerative spondylolisthesis. Twenty-four consecutive patients (age range 50–78 years) underwent primary surgery for isolated lumbar degenerative spondylolisthesis. The surgical procedure consisted of posterior decompression and pedicle screw instrumented fusion using autogeneous bone graft, with or without interbody fusion. Clinical and radiologic status were assessed using the Beaujon functional score and plain AP and lateral radiographs. A multivariate analysis was used to correlate the functional score increase with surgical procedure modifications and preoperative clinical and radiologic features in order to determine which of them led to better results. Eighteen patients completed the evaluation. Six others were lost to follow-up after a minimum of 0.87 years. Combining all the results, the mean follow-up was 2.87 years. The Beaujon score was improved in the 24 patients (P<0.001), and fusion was successful in all cases. Additional interbody fusion and preoperative leg pain were significantly correlated with larger score increase (P=0.016 and P=0.003). Posterior decompression and fusion is successful in treating lumbar degenerative spondylolisthesis. From this study, circumferential fusion improves the outcomes and leg pain is a fair indication for surgery.     

Functional outcome of surgical treatment for multilevel lumbar spinal stenosis

BACKGROUND: There is no consensus regarding the best treatment of patients with multilevel lumbar stenosis. We evaluated the clinical and radiological findings in 41 patients with complex degenerative spinal stenosis of the lumbar spine who were treated surgically. METHODS: Between 1997 and 2003, 41 patients suffering from degenerative lumbar spinal stenosis were included in a prospective clinical study. The spinal stenosis was multilevel in all patients and in 13 of them there was degenerative scoliosis, in 18 there was degenerative spondylolisthesis, and in 10 there was segmental instability. Plain radiographs, MRI and/or CT myelograms were obtained preoperatively. The patients were assessed clinically with the Oswestry disability index (ODI) and visual analog scale (VAS). Surgery included wide posterior decompression and fusion using a trans-pedicular instrumentation system and bone graft. RESULTS: After a mean follow-up of 3.7 (1-6) years, the patients' clinical improvement on the ODI and VAS was statistically significant. Recurrent stenosis was not observed, and 39 of 41 patients were satisfied with the outcome. 3 patients with improvement initially had later surgery because of instability. INTERPRETATION: The above-mentioned technique gives good and long lasting clinical results, when selection of patients is done carefully and when the spinal levels that are to be decompressed are selected accurately.     

Minimally invasive anterior lumbar interbody fusion followed by percutaneous pedicle screw fixation for isthmic spondylolisthesis.

BACKGROUND CONTEXT: Most surgeons have thought that posterior decompression is necessary to treat isthmic spondylolisthesis with leg pain. However, the surgical procedure not only requires wide muscle dissection but can also lead to spinal instability. The authors' treatment concept for isthmic spondylolisthesis is one-stage anterior reduction and posterior stabilization with minimally invasive surgical procedure without touching the spinal thecal sac and nerve. PURPOSE: To investigate a new surgical concept of minimally invasive anterior-posterior fusion without posterior decompression for the treatment of isthmic spondylolisthesis with leg pain. STUDY DESIGN: This is a retrospective study of 73 patients with isthmic spondylolisthesis who underwent minimally invasive anterior lumbar interbody fusion (mini-ALIF) followed by percutaneous pedicle screw fixation (PF) between October 2000 and February 2002. PATIENT SAMPLE: A total of 73 patients with low-grade isthmic spondylolisthesis (46 with Grade 1 and 27 with Grade 2) who underwent mini-ALIF followed by percutaneous PF were retrospectively analyzed. There were 20 men and 53 women, with a mean age of 50.6 (range, 19 to 77) years. All patients had low back pain and referred or radicular leg pain or neurogenic intermittent claudication in walking or standing. Average duration of symptoms was 26 (range, 3 to 120) months. OUTCOME MEASURES: The clinical outcome was graded according to the modified Macnab criteria. METHODS: The authors retrospectively reviewed clinical and radiological data of 73 patients who had isthmic spondylolisthesis. All patients underwent mini-ALIF and percutaneous PF on the same day between October 2000 and February 2002. The mean follow-up period was 16 months (range, 12 to 26). RESULTS: The mean operating time, blood loss and hospital stay were 210 minutes, 135 ml and 4.1 days, respectively. No blood transfusion was necessary. Clinical outcome was excellent in 26 patients (35.6%), good in 43 (58.9%), fair in 3 (4.1%) and poor in 1 (1.4%). The fusion rate was 97.3% (71 of 73). There were 6 cases (8.2%) of mini-ALIF complications and 6 (8.2%) of percutaneous PF complications. There were no postoperative neurologic deficits. CONCLUSIONS: Mini-ALIF followed by percutaneous PF is an efficacious alternative for low-grade isthmic spondylolisthesis, and posterior decompression is not necessary to relieve leg symptoms. This minimally invasive combined procedure offers many advantages, such as preservation of posterior arch, no nerve retraction, less blood loss, excellent cosmetic results, high fusion rate and early discharge.     

Surgical treatment of symptomatic degenerative lumbar spondylolisthesis by decompression and instrumented fusion

Degenerative spondylolisthesis is characterized by the slippage of one vertebral body over the one below, with association of intervertebral disc degeneration and degenerative arthritis of the facet joints, which cause spinal stenosis. The aim of this study was to evaluate the clinical and radiographic results of 22 patients with symptomatic degenerative spondylolisthesis, operated on by decompressive laminectomy and instrumented posterolateral fusion associated with interbody fusion (PLIF). Mean age at surgery was 64 years (range, 57–72). Clinical results were evaluated on a questionnaire at the last follow-up visit concerning postoperative low back and leg pain, restriction of daily life activities, and resumption of sports activity. Lumbar spine radiographs were used to evaluate the status of fixation devices, the reduction of the spondylolisthesis, the lumbar sagittal balance and the presence of spinal fusion. No intraoperative or postoperative complications were encountered. There were no superficial or deep infections, fixation device loosening, or hardware removal. Mean follow-up time was 4 years (range, 3–6 years). Clinical outcome was excellent or good in 19 patients and fair in 3 patients. Preoperatively, mean forward vertebral slipping on neutral lateral radiographs was 5 mm, while postoperatively it decreased to 3 mm. Preoperatively, mean sagittal motion was 3 mm and angular motion was 8°, while postoperatively these values decreased to 1 mm and 1°, respectively. This study demonstrated that spinal decompression followed by transpedicular instrumentation associated with PLIF technique is a valid surgical option for the treatment of degenerative spondylolisthesis with symptomatic spinal stenosis. Clinical outcome, intended as relief of pain and resumption of activity, was improved significantly and fusion rate was high.     

退变性腰椎滑脱症的手术治疗

目的探讨采用后路腰椎椎管减压、钉棒内固定并椎间植骨融合术和后路腰椎减压并Dynesys系统内固定手术治疗退变性腰椎滑脱的效果。方法应用后路腰椎椎间融合（posterior lumbar interbody fusion,PLIF）术进行椎管减压、钉棒系统固定并椎体间植骨融合手术治疗退变性腰椎滑脱37例;应用后路腰椎管减压并Dynesys内固定手术治疗退变性腰椎滑脱5例。结果随访9～39个月,平均26个月,腰痛疼痛视觉模拟量表（visual analogue scale,VAS）评分术前为8.7分,随访时为2.1分;腿痛VAS评分术前为7.6分,随访时为2.3分。术前Oswestry功能障碍指数（Oswestry disability index,ODI）为58.2%,随访时为21.2%。无严重手术并发症发生。术后X线片复查显示椎间高度均得到不同程度的恢复,滑脱椎体完全复位或者基本复位,椎间植骨融合。无融合器移位或螺钉松动、断裂。结论后路腰椎椎管减压、钉棒内固定并椎间植骨融合术和后路腰椎减压并Dynesys内固定手术治疗退变性腰椎滑脱效果满意,安全彻底的神经根管减压是取得满意临床效果的关键。     

Posterior lumbar interbody fusion for degenerative spondylolisthesis: restoration of sagittal balance using insert-and-rotate interbody spacers.

BACKGROUND CONTEXT: Although satisfactory clinical outcomes have been reported for degenerative spondylolisthesis using a variety of surgical techniques, its optimal management remains controversial. Laboratory and clinical evidence is emerging that if fusion surgery is undertaken, improved short- and longer-term outcomes may be achieved by correcting any sagittal deformity present. The insert-and-rotate posterior lumbar interbody fusion (PLIF) technique, first described by Jaslow in 1946, may enable surgeons to safely and effectively correct sagittal balance through a single posterior approach. PURPOSE: To examine the clinical outcomes and determine whether the focal sagittal imbalance associated with a degenerative lumbar spondylolisthesis can be safely and effectively corrected using a posterior distraction/reduction technique and insert-and-rotate interbody fusion spacers. STUDY DESIGN/SETTING: A prospective, single-cohort, observational study of the clinical outcomes and retrospective radiological review, in a series of 34 patients with degenerative spondylolisthesis, who underwent surgery between September 2000 and October 2002. PATIENT SAMPLE: Mean age of 65.1 years (range, 35 to 82 years). Thirty-two of the 34 patients underwent surgery principally for the relief of radicular leg pain. The principal indication for the fusion was the prevention of anticipated postdecompression instability in 68% of the patients. Mean preoperative slip was 20.0% (range, 12% to 33%). Mean preoperative focal lordosis was 13.2 degrees. OUTCOME MEASURES: Patients were administered pre- and postoperative clinical outcome surveys recording Visual Analogue Pain Score (VAS), Low Back Outcome Score (LBOS), Short Form (SF)-12 and patient satisfaction questionnaires. Pre- and postoperative measurements of the percentage slip and lumbar lordosis of the involved segments were available on 17 patients. Statistical analysis was done using a two tailed, paired t test. SURGICAL METHODS: Decompressive laminectomy was followed by reduction of the spondylolisthesis using intervertebral disc space distraction and pedicle screw instrumentation. The vertebral bodies were supported with bilateral intervertebral lordotic spacers, inserted on their sides and rotated 90 degrees before placing bone graft to either side of them, within the disc space. RESULTS: Mean follow-up time was 21.2 months (range, 12-32 months). No patients were lost to follow-up. Mean preoperative measures of VAS and LBOS of 5.3+/-2.2 and 24.8+/-15.6, respectively, improved to 2.2+/-2.1 (p<.001) and 44.8+/-18.0 (p<.001) at last follow-up. Thirty-one of 34 patients (91%) considered their outcome to be good or excellent. Mean preoperative slip reduced from 20.2% to 1.7% (92% correction, p<.001). Mean focal lordosis increased from 13.1 to 16.1 degrees (26.0% increase, p=.01). There were no device-related procedural complications. Postoperatively, three patients developed an ileus and one a possible deep wound infection, which settled on antibiotics. One patient required extension of his fusion at 12 months for adjacent segment stenosis. CONCLUSIONS: This series suggests that PLIF for degenerative spondylolisthesis using an insert-and-rotate technique can yield high levels of patient satisfaction with low levels of complications and substantial deformity correction using a posterior only approach. Longer-term outcome studies are required regarding the relevance of the restoration of spinal balance.     

Outcome of transpedicular screw fixation and posterior spinal fusion for degenerative spondylolisthesis.

Aims (1) To assess the results of decompression instrumentation and posterior spinal fusion for degenerative spondylolisthesis in a district general hospital. (2) To establish whether this procedure can be performed safely outside a specialised unit. Methods Thirty-one consecutive patients were included for this study. All underwent decompression instrumentation, pedicle screw fixation and posterior spinal fusion for degenerative spondylolisthesis in our unit. The average age was 56 (range 34–72) years with a mean follow-up of 3.7 years. Patients were assessed by their operative and post-operative complications, radiographic analysis and postal questionnaires; 25 (81%) patients replied to the questionnaire. Results Two cases each of dural tears, instrumentation failure and superficial wound infection, and one case of deep wound infection were found. There were no cases of neurological deficit, radiculopathy, recurrent stenosis or progression of deformity at the fused level. Radiological fusion rate was 87% and 88% were satisfied with the overall results; two (8%) patients said they would not have the same procedure again. An improvement in score outcome in terms of pain, mobility, sleep, analgesia and quality of life ( P <0.0001) was also noted. Conclusions Overall complications were 17%. An improved outcome was noted in terms of radiological fusion and patients' functional and satisfaction outcome in all those who underwent decompression pedicle screw fixation in our unit. We conclude that posterior spinal fusion can be performed safely outside a specialised unit.     

High failure rate of the interspinous distraction device (X-Stop) for the treatment of lumbar spinal stenosis caused by degenerative spondylolisthesis

The X-Stop interspinous distraction device has shown to be an attractive alternative to conventional surgical procedures in the treatment of symptomatic degenerative lumbar spinal stenosis. However, the effectiveness of the X-Stop in symptomatic degenerative lumbar spinal stenosis caused by degenerative spondylolisthesis is not known. A cohort of 12 consecutive patients with symptomatic lumbar spinal stenosis caused by degenerative spondylolisthesis were treated with the X-Stop interspinous distraction device. All patients had low back pain, neurogenic claudication and radiculopathy. Pre-operative radiographs revealed an average slip of 19.6%. MRI of the lumbosacral spine showed a severe stenosis. In ten patients, the X-Stop was placed at the L4–5 level, whereas two patients were treated at both, L3–4 and L4–5 level. The mean follow-up was 30.3 months. In eight patients a complete relief of symptoms was observed post-operatively, whereas the remaining 4 patients experienced no relief of symptoms. Recurrence of pain, neurogenic claudication, and worsening of neurological symptoms was observed in three patients within 24 months. Post-operative radiographs and MRI did not show any changes in the percentage of slip or spinal dimensions. Finally, secondary surgical treatment by decompression with posterolateral fusion was performed in seven patients (58%) within 24 months. In conclusion, the X-Stop interspinous distraction device showed an extremely high failure rate, defined as surgical re-intervention, after short term follow-up in patients with spinal stenosis caused by degenerative spondylolisthesis. We do not recommend the X-Stop for the treatment of spinal stenosis complicating degenerative spondylolisthesis.     

Increased risk of symptomatic progression of instability following decompression for lumbar canal stenosis in patients receiving chronic glucocorticoids therapy

Background

Lumbar decompression surgery is a commonly used treatment for degenerative lumbar spinal stenosis; however, some patients develop symptomatic spinal instability following decompression surgery. The objective of this study was to reveal risk factors for delayed instability following decompression surgery for lumbar spinal stenosis.

A pilot safety and efficacy study of OP-1 putty (rhBMP-7) as an adjunct to iliac crest autograft in posterolateral lumbar fusions

The ability of bone morphogenetic proteins (BMPs) to induce bone formation has led to an increasing interest in the potential for their use in fusion surgery. The purpose of this multi-center clinical pilot study was to evaluate the safety of one such BMP—osteogenic protein 1, in the form of OP-1 putty—combined with autograft for intertransverse process fusion of the lumbar spine in patients with symptomatic spinal stenosis and degenerative spondylolisthesis following spinal decompression. Twelve patients with spinal stenosis and degenerative lumbar spondylolisthesis underwent laminectomy and partial or complete medial facetectomy as required for decompression of the neural elements followed by intertransverse process fusion by placing iliac crest autograft and OP-1 putty between the decorticated transverse processes. No instrumentation was used. Patients were followed clinically using the Oswestry scale and radiographically using static and dynamic radiographs to assess their fusion status. Independent and blinded radiologists assessed the films for the presence of bridging bone between the transverse processes and measured translation and angulation on dynamic films using digital calipers. In addition to bridging bone, less than or equal to 5° of angular motion and less than or equal to 2 mm of translation were required to classify the patients as successfully fused, as per the definition of successful fusion provided by the FDA for use in clinical trials involving investigational devices to attain spinal fusion. Radiographic outcome was compared to a historical control (autograft alone fusion without instrumentation for the treatment of degenerative spondylolisthesis). All adverse events were recorded prospectively. The results showed 9 of the 12 patients (75%) obtained at least a 20% improvement in their preoperative Oswestry score, while 6 of 11 patients (55%) with radiographic follow-up achieved a solid fusion by the criteria used in this study. Bridging bone on the anteroposterior film was observed in 10 of the 11 patients (91%). No systemic toxicity, ectopic bone formation, recurrent stenosis or other adverse events related to the OP-1 putty implant were observed. A successful fusion was observed in slightly over half the patients in this study, using stringent criteria without adjunctive spinal instrumentation. This study did not demonstrate the superiority of OP-1 combined with autograft over an autograft alone historical control, in which the fusion rate was approximately 45%. The lack of adverse events related to the OP-1 putty implant in this study is in agreement with other studies supporting the safety of bone morphogenetic proteins in spinal surgery.