Thomas Andersen

Transforaminal lumbar interbody fusion (TLIF) versus posterolateral instrumented fusion (PLF) in degenerative lumbar disorders: a randomized clinical trial with 2-year follow-up

PurposeThe aim of the present study was to analyze outcome, with respect to functional disability, pain, fusion rate, and complications of patients treatedxa0with transforaminal lumbar interbody fusion (TLIF) in compared toxa0instrumented poserolateral fusion (PLF) alone, in low back pain. Spinal fusion has become a major procedure worldwide. However, conflicting results exist. Theoretical circumferential fusion could improve functional outcome. However, the theoretical advantages lack scientific documentation.MethodsProspective randomized clinical study with a 2-year follow-up period. From November 2003 to November 2008 100 patients with severe low back pain and radicular pain were randomly selected for either posterolateral lumbar fusion [titanium TSRH (Medtronic)] or transforaminal lumbar interbody fusion [titanium TSRH (Medtronic)] with anterior intervertebral support by tantalum cage (Implex/Zimmer). The primary outcome scores were obtained using Dallas Pain Questionnaire (DPQ), Oswestry disability Index, SF-36, and low back pain Rating Scale. All measures assessed the endpoints at 2-year follow-up after surgery.ResultsThe overall follow-up rate was 94xa0%. Sex ratio was 40/58. 51 patients had TLIF, 47 PLF. Mean age 49(TLIF)/45(PLF). No statistic difference in outcome between groups could be detected concerning daily activity, work leisure, anxiety/depression or social interest. We found no statistic difference concerning back pain or leg pain. In both the TLIF and the PLF groups the patients had significant improvement in functional outcome, back pain, and leg pain compared to preoperatively. Operation time and blood loss in the TLIF group were significantly higher than in the PLF group (pxa0<xa00.001). No statistic difference in fusion rates was detected.ConclusionsTransforaminal interbody fusion did not improve functional outcome in patients compared to posterolateral fusion. Both groups improved significantly in all categories compared to preoperatively. Operation time and blood loss were significantly higher in the TLIF group.

Prevalence of complications in neuromuscular scoliosis surgery: a literature meta-analysis from the past 15 years

PurposeOur objectives were primarily to review the published literature on complications in neuromuscular scoliosis (NMS) surgery and secondarily, by means of a meta-analysis, to determine the overall pooled rates (PR) of various complications associated with NMS surgery.MethodsPubMed and Embase databases were searched for studies reporting the outcomes and complications of NMS surgery, published from 1997 to May 2011. We focused on NMS as defined by the Scoliosis Research Society’s classification. We measured the pooled estimate of the overall complication rates (PR) using a random effects meta-analytic model. This model considers both intra- and inter-study variation in calculating PR.ResultsSystematic review and meta-analysis were performed for 68 cohort and case–control studies with a total of 15,218 NMS patients. Pulmonary complications were the most reported (PRxa0=xa022.71xa0%) followed by implant complications (PRxa0=xa012.51xa0%), infections (PRxa0=xa010.91xa0%), neurological complications (PRxa0=xa03.01xa0%) and pseudoarthrosis (PRxa0=xa01.88xa0%). Revision, removal and extension of implant had highest PR (7.87xa0%) followed by malplacement of the pedicle screws (4.81xa0%). Rates of individual studies have moderate to high variability. The studies were heterogeneous in methodology and outcome types, which are plausible explanations for the variability; sensitivity analysis with respect to age at surgery, sample size, publication year and diagnosis could also partly explain this variability. In regard to surgical complications affiliated with various surgical techniques in NMS, the level of evidence of published literature ranges between 2+xa0to 2−; the subsequent recommendations are level C.ConclusionNMS patients have diverse and high complication rates after scoliosis surgery. High PRs of complications warrant more attention from the surgical community. Although the PR of all complications are affected by heterogeneity, they nevertheless provide valuable insights into the impact of methodological settings (sample size), patient characteristics (age at surgery), and continual advances in patient care on complication rates.

The positive effect of posterolateral lumbar spinal fusion is preserved at long-term follow-up: a RCT with 11–13 year follow-up

Introduction Few studies have investigated the long-term effect of posterolateral lumbar spinal fusion on functional outcome. Aim To investigate the long-term result after posterolateral lumbar spinal fusion with and without pedicle screw instrumentation. Methods Questionnaire survey of 129 patients originally randomised to posterolateral lumbar spinal fusion with or without pedicle screw instrumentation. Follow-up included Dallas Pain Questionnaire (DPQ), Oswestry Disability Index (ODI), SF-36 and a question regarding willingness to undergo the procedure again knowing the result as global outcome parameter. Results Follow-up was 83% of the original study population (107 patients). Average follow-up time was 12xa0years (range 11–13xa0years). DPQ-scores were significantly lower than preoperatively in both groups (Pxa0<xa00.005) and no drift towards the preoperative level was seen. No difference between the two groups were observed (instrumented vs. non-instrumented): DPQ Daily Activity mean 37.0 versus 32.0, ODI mean 33.4 versus 30.6, SF-36 PCS mean 38.8 versus 39.8, SF-36 MCS mean 49.0 versus 53.3. About 71% in both groups were answered positively to the global outcome question. Patients who had retired due to low back pain had poorer outcome than patients retired for other reasons, best outcome was seen in patients still at work (Pxa0=xa00.01 or less in all questionnaires, except SF-36 MCS Pxa0=xa00.08). Discussion Improvement in functional outcome is preserved for 10 or more years after posterolateral lumbar spinal fusion. No difference between instrumented fusion and non-instrumented fusion was observed. Patients who have to retired due to low back pain have the smallest improvement.

Pain 5 years after instrumented and non-instrumented posterolateral lumbar spinal fusion

Pain drawings have been used in spine surgery for diagnostic use and psychological evaluation of fusion candidates; they have rarely been used to evaluate pain status after spinal fusion. This study is a 5-year follow-up on a randomised clinical trial assigning patients to posterolateral spinal fusion with or without pedicle screw instrumentation. Patients were mailed a pain drawing and questionnaires including questions regarding work, social status, smoking status, the Dallas Pain Questionnaire (DPQ), and the Low Back Pain Rating Scale (LBPRS). Pain drawings were scored using a visual inspection method and a surface-based point scoring and evaluated for the presence of donor site pain. Pain drawings from 109 patients (87% of the initially included patients), 56 men and 53 women, mean age at follow-up 51 years, were analysed. Fifty-three patients had undergone an instrumented fusion and 56 a non-instrumented fusion. Some presence of low back pain was marked by 79% and leg pain by 69%. Sixty-two percent of the pain drawings were classified as organic and 38% as non-organic. There was no difference between the instrumented and the uninstrumented group. DPQ and LBPRS scores were higher in the non-organic group (P=0.007). Using the point scoring, no difference between the instrumented and the uninstrumented group was seen. The results of the point scoring were found to correlate with the DPQ and LBPRS scores (P=0.001). Working patients (39%) had significantly better scores than the rest. Ten percent of the patients had donor site pain. Twenty percent of spinal fusion patients are totally pain free at 5-year follow-up. Ten percent still experience donor site pain. In general, instrumentation does not affect the amount and localisation of pain 5 years after lumbar spinal fusion surgery. The pain drawing seems to be a valuable tool when following spinal fusion patients, but its use as prognostic marker in connection with fusion surgery needs further investigation.

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.

Transforaminal lumbar interbody fusion vs. posterolateral instrumented fusion: cost-utility evaluation along side an RCT with a 2-year follow-up

PurposeLong-lasting low back pain is an increasing problem, and for some patients surgery is the final option for improvement. Several techniques for spinal fusion are available and the optimal technique remains uncertain. The objective of this study was to assess the cost-effectiveness and cost-utility of transforaminal lumbar interbody fusion (TLIF) compared to posterolateral instrumented fusion (PLF) from the societal perspective.Methods100 Patients were randomized to TLIF or PLF (51/49) and followed for 2xa0years. Cost data were acquired from national registers, and outcomes were measured using the Oswestry Disability Index and SF-6D questionnaires. Conventional cost-effectiveness methodology was employed to estimate net benefit and to illustrate cost-effectiveness acceptability curves. The statistical analysis was based on means and bootstrapped confidence intervals.ResultsResults showed no statistically significant difference in either cost or effects although a tendency for the TLIF regimen being more costly on bed days (€2,554) and production loss (€1,915) was observed. The probability that TLIF would be cost-effective did not exceed 30xa0% for any threshold of willingness to pay per quality-adjusted life year. Sensitivity analysis was conducted and supported the statistical model for handling of missing data.ConclusionTLIF does not seem to be a relevant alternative to PLF from a socioeconomic, societal point of view.

Fusion mass bone quality after uninstrumented spinal fusion in older patients.

Older people are at increased risk of non-union after spinal fusion, but little is known about the factors determining the quality of the fusion mass in this patient group. The aim of this study was to investigate fusion mass bone quality after uninstrumented spinal fusion and to evaluate if it could be improved by additional direct current (DC) electrical stimulation. A multicenter RCT compared 40 and 100xa0μA DC stimulation with a control group of uninstrumented posterolateral fusion in patients older than 60xa0years. This report comprised 80 patients who underwent DEXA scanning at the 1xa0year follow-up. The study population consisted of 29 men with a mean age of 72xa0years (range 62–85) and 51 women with a mean age of 72xa0years (range 61–84). All patients underwent DEXA scanning of their fusion mass. Fusion rate was assessed at the 2xa0year follow-up using thin slice CT scanning. DC electrical stimulation did not improve fusion mass bone quality. Smokers had lower fusion mass BMD (0.447xa0g/cm2) compared to non-smokers (0.517xa0g/cm2) (Pxa0=xa00.086). Women had lower fusion mass BMD (0.460xa0g/cm2) compared to men (0.552xa0g/cm2) (Pxa0=xa00.057). Using linear regression, fusion mass bone quality, measured as BMD, was significantly influenced by gender, age of the patient, bone density of the remaining part of the lumbar spine, amount of bone graft applied and smoking. Fusion rates in this cohort was 34% in the control group and 33 and 43% in the 40 and 100xa0μA groups, respectively (not significant). Patients classified as fused after 2xa0years had significant higher fusion mass BMD at 1xa0year (0.592 vs. 0.466xa0g/cm2, Pxa0=xa00.0001). Fusion mass bone quality in older patients depends on several factors. Special attention should be given to women with manifest or borderline osteoporosis. Furthermore, bone graft materials with inductive potential might be considered for this patient population.

The predictive value of pain drawings in lumbar spinal fusion surgery

BACKGROUND CONTEXTnPain drawings have been used extensively in spine surgery. It has been associated with inferior outcome after disc and stenosis surgery. Results regarding the predictive value in fusion surgery have been conflicting.nnnPURPOSEnTo evaluate the predictive value of pain drawings in relation to outcome after lumbar spinal fusion. To investigate if there are differences between spondylolisthesis patients and patients with degenerative disease as well as between patients with or without radicular pain.nnnSTUDY DESIGNnProspective clinical cohort with a minimum of 1-year follow-up.nnnPATIENT SAMPLEnOne hundred thirty-five patients undergoing lumbar spinal fusion. Fifty-seven men and 78 women, mean age 44 years (range 21-59 years).nnnOUTCOME MEASURESnDallas Pain Questionnaire (DPQ), Low Back Pain Rating Scale (LBPRS) pain index and patient satisfaction. Minimal clinical important difference was defined for the LBPRS score.nnnMETHODSnPain drawings were classified, using the visual inspection method, as organic or nonorganic and correlated to outcomes. Multivariate adjustment for several possible confounding variables was done using logistic regression analysis.nnnRESULTSnThirty-three percent of the drawings were classified as nonorganic. Nonorganic drawings were associated with significantly higher DPQ and LBPRS scores preoperatively and at follow-up. Differences between organic and nonorganic drawings were larger in spondylolisthesis patients than in patients with degenerative disorders. Nonorganic pain drawings were associated with poorer outcome in patients with low back pain and radicular symptoms, however, not in patients without radicular symptoms. A nonorganic pain drawing predicted negative patient satisfaction with odds ratio (OR) 3.01 (95% confidence interval (CI): 1.14-8.55, p=.027) but had no significant predictive value with respect to improvement in the LBPRS pain index OR 1.92 (95% CI: 0.82-4.47, p=.132).nnnCONCLUSIONSnA nonorganic pain drawing was a significant risk factor for inferior outcome after spinal fusion surgery. The predictive value did not allow for patient selection.

Evaluation of a Dallas Pain Questionnaire classification in relation to outcome in lumbar spinal fusion

Several studies have suggested that psychosocial distress is an important predictor of negative outcome in lumbar spine surgery. Ozguler etxa0al. [Spine 27:1783–1789, 2002, 18] described a classification tool for low back pain patients using the Dallas Pain Questionnaire (DPQ) which included a measure of distress. We wanted to evaluate the ability of this classification tool to predict the outcome in spinal fusion patients. Five hundred and sixty-six patients (239 men, 327 women; mean age 46, range 18–81) operated between 1992 and 2002, with a complete DPQ preoperatively and after a minimum of 1-year follow-up, were included. They were classified preoperatively and at follow-up into four groups: group 1 (slight disability), group 2 (intermediate disability), group 3 (major disability) and group 4 (major disability and emotional distress). Using logistic regression, seven predictor variables were investigated: age (−39xa0years/40–59xa0years/60+xa0years), Gender (male/female), Indication (spondylolisthesis/primary degeneration/secondary degeneration), Work status (working/without work or on sick leave/retired or pensioned), Duration of pain (less than 1xa0year/1–2xa0years/more than 2xa0years), Presence of radiating pain (yes/no) and disability/distress [intermediate disability (group 1–2)/major disability (group 3)/major disability and distress (group 4)]. The outcome variable was disability at follow-up (lowxa0=xa0group1xa0+xa02/highxa0=xa0group 3xa0+xa04). Preoperative classification was group 1, 1%; group 2, 14%; group 3, 37%; group 4, 48%. Variables found to predict high disability at follow-up were secondary degeneration Odds Ratio (OR) 1.61 (P=0.020), being retired/pensioned OR 3.48 (P<0.0005), age between 40–59xa0years OR 1.68 (P=0.011), belonging to group 3 OR 2.69 (P=0.003) or belonging to group 4 OR 5.53 (P<0.0005). The classification based on the DPQ were able to identify lumbar spinal fusion patients with a considerable amount of psychological distress in their symptomatology. Furthermore, the presence of distress, as determined by this classification, was a highly significant risk factor for inferior outcome.

Degenerative Spondylolisthesis Is Associated with Low Spinal Bone Density: A Comparative Study between Spinal Stenosis and Degenerative Spondylolisthesis

Spinal stenosis and degenerative spondylolisthesis share many symptoms and the same treatment, but their causes remain unclear. Bone mineral density has been suggested to play a role. The aim of this study was to investigate differences in spinal bone density between spinal stenosis and degenerative spondylolisthesis patients. 81 patients older than 60 years, who underwent DXA-scanning of their lumbar spine one year after a lumbar spinal fusion procedure, were included. Radiographs were assessed for disc height, vertebral wedging, and osteophytosis. Pain was assessed using the Low Back Pain Rating Scale pain index. T-score of the lumbar spine was significantly lower among degenerative spondylolisthesis patients compared with spinal stenosis patients (−1.52 versus −0.52, P = 0.04). Thirty-nine percent of degenerative spondylolisthesis patients were classified as osteoporotic and further 30% osteopenic compared to only 9% of spinal stenosis patients being osteoporotic and 30% osteopenic (P = 0.01). Pain levels tended to increase with poorer bone status (P = 0.06). Patients treated surgically for symptomatic degenerative spondylolisthesis have much lower bone mass than patients of similar age treated surgically for spinal stenosis. Low BMD might play a role in the development of the degenerative spondylolisthesis, further studies are needed to clarify this.