Factors affecting lumbar spinal fusion

There is little information on the effect of nonsurgical factors or postoperative anemia on achieving spinal fusion. In a prospective cohort study of 184 consecutive lumbar spinal fusions, we obtained data on socioeconomic, clinical, radiologic, and traditional surgical factors and analyzed associations between these factors and fusion status at 6 months post surgery. The overall fusion rate was 74%. Among the surgical factors, use of pedicle screw fixation (p = 0.005) predicted fusion success; postoperative anemia (hematocrit < 30%; p = 0.003) and a history of smoking (p = 0.050) predicted fusion failure. However, when the surgical factors were analyzed together with clinical and socioeconomic factors, back pain greater than or equal to leg pain (p < 0.001) and patients working at the initial visit (p = 0.001) predicted fusion success; shoulder pain at the initial visit (p < 0.001) and a family history of back surgery (p = 0.006) predicted fusion failure. These factors were stronger predictors of fusion status than were traditional surgical factors.     

Surgical fusion in childhood spondylolisthesis

Twenty cases of surgical fusion for spondylolisthesis were reviewed at the Scottish Rite Hospital (Atlanta, GA, U.S.A.) to determine whether a procedure other than a simple posterolateral fusion is necessary for most patients. The patients were treated postoperatively with pantaloon spica cast immobilization. The fusion rate was high (90%), and patient satisfaction was high. One patient developed neurologic loss postoperatively. Two patients' slips progressed greater than 10% before solid fusion occurred. Thus, bilateral posterolateral fusion, followed by pantaloon spica cast immobilization, is effective for patients with symptomatic spondylolisthesis or asymptomatic children with grade 3 or greater slips. Reduction was not performed in this series.     

后路椎间融合术治疗成人腰椎滑脱的前瞻性研究

目的前瞻性比较采用自体髂骨块和椎间融合器治疗成人腰椎滑脱的效果。方法自1998年2月～2002年2月治疗78例腰椎滑脱患者,所有患者均行椎弓根螺钉固定、后路椎间融合术,根据椎间融合材料的不同,前瞻性将患者随机分为融合器组36例(采用后方斜向单枚椎间融合器)和自体骨组42例(采用自体髂骨块)。男33例,女45例;年龄35～59岁,平均43岁。其中Ⅰ度滑脱29例,Ⅱ度滑脱39例,Ⅲ度滑脱10例。比较两组患者的基本情况、临床效果和影像学结果(融合率和手术节段椎间隙高度的变化)。结果术后随访2年～3年7个月,平均35个月。两组在性别、年龄、滑脱程度、手术时间、失血量以及住院时间上差异无显著性,两组患者均无严重并发症。融合器组优良率为88.8%,自体骨组为83.2%(P=0.99)。术后1年融合器组的融合率为86.1%,自体骨组为83.3%,两组间差异无显著性意义(P=0.87);最终随访时椎间隙高度融合器组平均减少1.7 mm,自体骨组平均减少2.6 mm,两组间差异有非常显著性意义(t=1.38,P< 0.005)。结论采用自体骨为植骨材料者术后椎间隙高度丢失明显增加,但两组之间融合率和临床优良率差异无显著性。椎间融合器和自体髂骨块均可以作为腰椎滑脱后路椎间融合的植骨材料,临床疗效好。     

Single segment of posterior lumbar interbody fusion for adult isthmic spondylolisthesis: reduction or fusion in situ

Objective

We prospectively compared surgical reduction or fusion in situ with posterior lumbar interbody fusion (PLIF) for adult isthmic spondylolisthesis in terms of surgical invasiveness, clinical and radiographical outcomes, and complications.

Methods

From January 2006 to June 2008, 88 adult patients with isthmic spondylolisthesis who underwent surgical treatment in our unit were randomized to reduced group (group 1, n = 45) and in situ group (group 2, n = 43), and followed up for average 32.5 months (range 24–54 months). The clinical and radiographical outcomes were compared between the two groups.

Results

The average operative time and blood loss during surgery showed insignificant difference (p > 0.05) between two groups. The radiological outcomes were significantly better in group 1, but there was no significant difference between two groups of clinical outcomes, depicting as VAS, ODI, JOA and patients’ satisfaction surveys. Incident rate of surgical complications was similar in two groups, but in group 1 the complication seemed more severe because of two patients with neurological symptoms.

Conclusions

For the adult isthmic spondylolisthesis without degenerative disease in adjacent level, single segment of PLIF with pedicle screw fixation is an effective and safe surgical procedure regardless of whether additional reduction had been conducted or not. Better radiological outcome does not mean better clinical outcome.     

Posterolateral fusion for spondylolisthesis in adolescence

Previous reports of posterolateral fusion for treatment of adolescent spondylolisthesis at L5-S1 suggest that persistent slippage is a significant problem in the postoperative period. Of 40 adolescent patients who underwent posterolateral fusion for L5-S1 spondylolisthesis, 23 demonstrated Grade 3 slip or worse. Two patients had progression of the slip postoperatively with subsequent spontaneous healing. All patients had complete incorporation of bone graft with resolution of neurologic deficits and pain. Improvement in results is attributed to the surgical technique and to postoperative casting. The displacement index, a new method to document relative L5-S1 position, is described.     

Factors affecting survival in adult patients with massive burns

Objective: To identify treatment-related factors associated with mortality in massively burned adult patients. Methods: This retrospective cohort study examined survival outcomes at a burn unit of 54 beds and 10 burn ICU beds, totaling 900 admissions per year. The cases of 102 adult patients, admitted consecutively from January 1993 to October 2007, with massive burns (burn area > 70% of the total body surface area, TBSA) were studied. Relevant variables were recorded from the initial injury and throughout the hospital course. Survival analysis, based on univariate and stepwise multivariate Cox proportional hazards regression, was performed to determine which variables predicted mortality. Results: The overall mortality rate was 30.4%. Burn size, severe inhalation injury, full-thickness burns, serum creatinine levels, inotropic support, platelet counts < 20,000 per mm³, sepsis and ventilator dependency were significantly associated with mortality as determined by univariate analysis. Only sepsis, ventilator dependency and platelet counts were significant independent predictors of mortality as determined by multivariate analysis. Conclusions: Sepsis, ventilator dependence (indicating severe respiratory complications), and low platelet counts (indicating thrombocytopenia) are associated with increased mortality risk in adult patients with massive burns. Methods should be sought to ameliorate these complications during treatment in burn-care units.     

Anterior interbody fusion for spondylolisthesis

We evaluated the clinical and radiologic results and the immobilizing effect of the Knight-Kim brace for bony union in 75 consecutive cases of spondylolisthesis treated by anterior interbody fusion. The fifth lumbar vertebra was the most common site involved (55%). The patients were followed for a minimum of 2 1/2 years (range: 2 1/2 to 14; average: 4.5). All cases were approached retroperitoneally, and autogenous bone graft was obtained from the iliac crest. The donor site was reconstructed by polymethylmethacrylate bone cement. Among the 75 cases of grade I, II, and III slippage according to Meyerding's grading system, 58 cases (77%) showed complete bony union after 1 year follow up. Excellent and good clinical results were obtained in 65 cases (87%) at 1 year postoperatively. The state of bony union did not always correlate with the clinical symptoms. We conclude that the simple Knight-Kim back brace was valuable for postoperative immobilization.     

Posterior lumbar interbody fusion for adult isthmic spondylolisthesis: a comparison of fusion with one or two cages

Between March 2000 and February 2006, we carried out a prospective study of 100 patients with a low-grade isthmic spondylolisthesis (Meyerding grade II or below), who were randomised to receive a single-level and instrumented posterior lumbar interbody fusion with either one or two cages. The minimum follow-up was for two years. At this stage 91 patients were available for review. A total of 47 patients received one cage (group 1) and 44 two cages (group 2). The clinical and radiological outcomes of the two groups were compared. There were no significant differences between the two groups in terms of post-operative pain, Oswestry Disability Score, clinical results, complication rate, percentage of post-operative slip, anterior fusion rate or posterior fusion rate. On the other hand, the mean operating time was 144 minutes (100 to 240) for patients in group 1 and 167 minutes (110 to 270) for those in group 2 (p = 0.0002). The mean blood loss up to the end of the first post-operative day was 756 ml (510 to 1440) in group 1 and 817 ml (620 to 1730) in group 2 (p < 0.0001). Our results suggest that an instrumented posterior lumbar interbody fusion performed with either one or two cages in addition to a bone graft around the cage has a low rate of complications and a high fusion rate. The clinical outcomes were good in most cases, regardless of whether one or two cages had been used.     

Radiographic analysis of transforaminal lumbar interbody fusion for the treatment of adult isthmic spondylolisthesis

The radiographs of 35 consecutive adult patients with isthmic spondylolisthesis who underwent a transforaminal lumbar interbody fusion (TLIF) with one or two Brantigan carbon fiber cages and pedicle screw instrumentation were evaluated. Anterolisthesis, disk space height, and slip angle were measured in preoperative and postoperative standing neutral radiographs. Anterolisthesis was reduced and disk space height was increased with the TLIF procedure. Average slip angle, however, was not significantly altered. The restoration of lordosis across the listhetic disk space correlated with a more anterior placement of the interbody cage within the disk space. The TLIF technique, performed with the Brantigan cage and pedicle screw instrumentation, appears to be able to restore disk height and reduce forward translation in patients with isthmic spondylolisthesis, but improvement in sagittal alignment is dependent upon anterior placement of the interbody device.     

Factors affecting mortality rate with iliac vein injuries

Over an 8-year period, 49 patients were treated for iliac vein injuries with 25 (51%) deaths. The iliac vein injuries and their mortality rates (MR) were: common iliac vein--40% (6/15), internal iliac vein--65% (9/14), external iliac vein--29% (4/14), and two or more iliac veins--100% (6/6). This MR (51%) was much higher than those (18% to 38%) found in other series. The factors associated with this significantly increased MR were: Trauma Score less than 11 (MR = 71% or 24/35), initial OR systolic BP less than 70 mm Hg (MR = 89% or 15/17), ISS greater than 28 (MR = 65% or 24/37), 10 or more units of blood in the first 24 hours (MR = 65% or 22/34), and no obtainable BP on admission to the ED (MR = 65% or 15/22). Although the overall calculated probability of survival (Ps) by TRISS methodology was 0.43, several deaths might have been prevented by more complete resuscitation including restoration of core temperature above 34 degrees or 35 degrees C, and by packing the pelvis and closing rather than allowing three or more separate additional hypotensive episodes to occur while attempting definitive control of bleeding vessels.     

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.     

Factors affecting the rate of disappearance of sevoflurane in Baralyme

The effects of temperature, water and Baralyme exhaustion on the rate of disappearance of sevoflurane in Baralyme were studied in an in vitro model. We found that the rate of disappearance of sevoflurane in Baralyme increased as the temperature increased and decreased as the concentration of water increased. The disappearance of sevoflurane also decreased in the presence of exhausted Baralyme compared with fresh Baralyme. The slower rate of disappearance of sevoflurane in Baralyme in the presence of water and Baralyme exhaustion suggests that the disappearance of sevoflurane may be self-limiting in the clinical setting.     

腰椎滑脱与腰椎融合

腰椎滑脱是引起腰背痛及神经根性症状的常见原因。腰椎滑脱融合的适用范围各不相同,后外侧融合较少单独应用,多联合椎体间融合形成360°环形融合;前路椎体间融合及椎板后复合体回置因存在一定的并发症,应用受到限制;后路椎体间融合术操作相对简单、费用低、损伤小、融合率高,值得推荐;经椎间孔椎体间融合不涉及椎管内,适用范围广,安全性好,在临床上获得较好应用;微创经椎间孔椎体间融合、极外侧椎体间融合具有一定技术优势,且创伤小、出血少、融合率高、患者术后恢复快而逐渐受到临床认可,将成为腰椎融合术未来发展方向,但需较长学习曲线,手术本身存在一定的并发症,故应严格掌握适应证。     

Posterolateral versus posterior interbody fusion in isthmic spondylolisthesis

Spondylolisthesis is a heterogeneous disorder characterized by subluxation of a vertebral body over another in the sagittal plane. Its most common form is isthmic spondylolisthesis (IS). This study aims to compare clinical outcomes of posterolateral fusion (PLF) with posterior lumbar interbody fusion (PLIF) with posterior instrumentation in the treatment of IS. We performed a randomized prospective study in which 80 patients out of a total of 85 patients with IS were randomly allocated to one of two groups: PLF with posterior instrumentation (group I) or PLIF with posterior instrumentation (group II). Posterior decompression was performed in the patients. The Oswestry low back pain disability (OLBP) scale and Visual Analogue Scale (VAS) were used to evaluate the quality of life (QoL) and pain, respectively. Fisher's exact test was used to evaluate fusion rate and the Mann-Whitney U test was used to compare categorical data. Fusion in group II was significantly better than in group I (p=0.012). Improvement in low back pain was statistically more significant in group I (p=0.001). The incidence of neurogenic claudication was significantly lower in group I than in group II (p=0.004). In group I, there was no significant correlation between slip Meyerding grade and disc space height, radicular pain, and low back pain. There was no significant difference in post-operative complications at 1-year follow-up. Our data showed that PLF with posterior instrumentation provides better clinical outcomes and more improvement in low back pain compared to PLIF with posterior instrumentation despite the low fusion rate.     

One stage reduction and fusion for spondylolisthesis

Summary A new method of reduction and fixation of spondylolisthesis and spondyloptosis is described. It is carried out in one stage through a posterior approach. Two self-locking plates are fixed to the sacrum and two double threaded screws inserted into the body of L5. The position is restored by lifting L5 up to the plates. An interbody fusion is carried out with autologous bone grafts. The results in 51 cases, with a minimum follow up of 6 months, are reported.

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Résumé L'auteur décrit une nouvelle méthode de réduction et de fixation du spondylolisthésis et de la spondyloptose. Elle est réalisée en un temps par voie postérieure. Deux plaques auto-bloquantes sont fixées au sacrum et deux doubles vis filetées sont insérées dans le corps de L5. La réduction est obtenue en amenant L5 au contact des plaques. Une arthrodèse lombo-sacrée est effectuée à l'aide de greffons autologues.On présente les résultats de 51 cas, avec un recul minimal de 6 mois.