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.
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 100 μA DC stimulation with a control group of uninstrumented posterolateral fusion in patients older than 60 years. This report comprised 80 patients who underwent DEXA scanning at the 1 year follow-up. The study population consisted of 29 men with a mean age of 72 years (range 62–85) and 51 women with a mean age of 72 years (range 61–84). All patients underwent DEXA scanning of their fusion mass. Fusion rate was assessed at the 2 year follow-up using thin slice CT scanning. DC electrical stimulation did not improve fusion mass bone quality. Smokers had lower fusion mass BMD (0.447 g/cm2) compared to non-smokers (0.517 g/cm2) (P = 0.086). Women had lower fusion mass BMD (0.460 g/cm2) compared to men (0.552 g/cm2) (P = 0.057). 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 100 μA groups, respectively (not significant). Patients classified as fused after 2 years had significant higher fusion mass BMD at 1 year (0.592 vs. 0.466 g/cm2, P = 0.0001). 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.
Spinal fusion; Randomised clinical trial; Bone mineral density; Electrical stimulation; Bone graft; Age; Smoking
The bone–screw interface has been indicated as the weak link in pedicle screw spine fixation. Bisphosphonate treatment may have the effect of improving bone–screw interface fixation in spine fusion by inhibiting bone resorption. An experimental study was conducted using a porcine model to evaluate the influence of alendronate treatment on bone–pedicle screw interface fixation. Eleven pigs in the treatment group received alendronate 10 mg/day orally for three months postoperatively. The other 11 pigs served as a control group. Posterior lateral fusion with the CD Horizon pedicle screw system was performed with autograft on the lumbar spine on all animals. Biomechanical torsion test and histomorphometric parameters of screw fixation were evaluated three months after the operation. The maximum torque and initial angular stiffness of the treatment group was higher than that of the control group, but there was no statistical significance. The bone–screw contact surface was 23.3 ± 10% for the treatment group and 9.8 ± 5.9% for the control group (P < 0.01). This study indicated that alendronate treatment increased bone purchase of stainless steel screw surfaces.
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.
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 12 years (range 11–13 years). DPQ-scores were significantly lower than preoperatively in both groups (P < 0.005) 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 (P = 0.01 or less in all questionnaires, except SF-36 MCS P = 0.08). 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.
Lumbar spinal fusion; Randomised clinical trial; Outcome
Recently, Christensen et al. reported the clinical effects of a low-cost rehabilitation program equally efficient to a relatively intensive program of individual, physiotherapist-guided exercise therapy. Yet, the low-cost approach is not fully supported as an optimal strategy until a full-scale economic evaluation, including extra-hospital effects such as service utilization in the primary health care sector and return-to-work, is conducted. The objective of this study was to conduct such evalution i.e. investigate the cost-effectiveness of (1) a low-cost rehabilitation regimen with a behavioural element and (2) a regimen of individual exercise therapy, both in comparison with usual practice, from a health economic, societal perspective. Study design was a cost-effectiveness evaluation of an RCT with a 2-year follow-up. Ninety patients having had posterolateral or circumferential fusion (indicated by chronic low back pain and localized pathology) were randomized 3 months after their spinal fusion. Validated pain- and disability index scales were applied at baseline and at 2 years postoperative. Costs were measured in a full-scale societal perspective. The probability of the behavioural approach being cost-effective was close to 1 given pain as the prioritized effect measure, and 0.8 to 0.6 (dependent on willingness to pay per effect unit) given disability as the prioritized effect measure. The probability of the exercise therapy approach being cost-effective was modest due to inferior effectiveness. Results proved robust to relevant sensitivity analysis although a differentiated cost-effectiveness ratio between males and females was suspected. In conclusion, a simple behavioural extension, of setting up group meetings for patients, to a regimen with a strict physiotherapeutic focus was found cost-effective, whereas the cost-effectiveness of increasing frequency and guidance of a traditional physiotherapeutic regimen was unlikely in present trial setting.
Rehabilitation; Lumbar spinal fusion; Chronic low back pain; Health economic evaluation; Cost-effectiveness evaluation
Up to one third of patients undergoing lumbar spinal fusion show no improvement after the procedure and thus, despite evidence from RCTs, there might be a rationale for observational studies clarifying indications. Similarly, selection of the right patients for the right procedure could have significant impact on cost-effectiveness, which in some countries, in turn, affects whether procedures are to be available through the National Health Service. The aim of this study was to investigate determinants of cost-effectiveness in lumbar spinal fusion. An observational cohort study with 2-year follow-up was conducted: 695 patients who underwent lumbar spinal fusion from 1996 to 2002 were included and followed for 2 years. Patients had a localized segmental pathology and were diagnosed with MRI-verified isthmic spondylolisthesis (26%) or disc degeneration (74%). The surgical techniques were non-instrumented posterolateral fusion (14%), instrumented posterolateral fusion (54%), and circumferential fusion (32%). Societal costs and improvement in functional disability (Dallas Pain Questionnaire) were transformed into a net benefit measure. Classical linear regression of the net benefit was conducted using predictors of age, sex, diagnosis, duration of pain, smoking habits, occupational status, severity of disability, emotional distress, surgical technique, and number of levels fused. The main results were that two determinants were found to negatively influence net benefit: smoking and diagnosis, whereas two others were found to be positively associated with the net benefit: severe disability and emotional distress. In conclusion, predicting net benefit reverses the picture usually seen in studies predicting clinical outcomes, because the response variable is based on improvement over time rather than end-point measures alone. Smoking habits, diagnosis, pre-operative disability, and pre-operative emotional distress were found to be significantly associated with the net benefit of spinal fusion.
Lumbar spinal fusion; Chronic low back pain; Economics; Net benefit; Determinants
The goal of this systematic literature review was to assess the evidence for cost-effectiveness of various surgical techniques in lumbar spinal fusion in conformity with the guidelines provided by the Cochrane Back Review Group. As new technology continuously emerges and divergent directions in clinical practice are present, economic evaluation is needed in order to facilitate the decision-makers’ budget allocations. NHS Economic Evaluation Database, MEDLINE, EMBASE and Cochrane Library were searched. Two independent reviewers (one clinical content expert and one economic content expert) applied the eligibility criteria. A list of criteria for methodological quality assessment was established by merging the criteria recommended by leading health economists with the criteria recommended by the Cochrane Back Review Group. The two reviewers independently scored the selected literature and the disagreement was resolved by means of consensus following discussion. Key data were extracted and the level of evidence concluded. Seven studies were eligible; these studies reflected the diversified choices of economic methodology, study populations (diagnosis), outcome measures and comparators. At the conclusion of quality assessment, the methodological quality of three studies was judged credible. Two studies investigated posteolateral fusion (PLF) ± instrumentation in different populations: one investigated non-specific low back pain and one investigated degenerative stenosis + spondylolisthesis. Both studies reflected that cost-effectiveness of instrumentation in PLF is not convincing. The third study concerned the question of circumferential vs anterior lumbar interbody fusion and found a non-significant difference between the techniques. In conclusion, the literature is limited and, in view of the fact that the clinical effects are statistically synonymous, it does not support the use of high-cost techniques. There is a great potential for improvement of methodological quality in economic evaluations of lumbar spinal fusion and further research is imperative.
Economics; Cost-effectiveness; Spinal fusion; Systematic review; Lowback pain
Very few studies have investigated the effects or costs of rehabilitation regimens following lumbar spinal fusion. The effectiveness of in-hospital rehabilitation regimens has substantial impact on patients’ demands in the primary health care sector. The aim of this study was to investigate patient-articulated demands to the primary health care sector following lumbar spinal fusion and three different in-hospital rehabilitation regimens in a prospective, randomized study with a 2-year follow-up. Ninety patients were randomized 3 months post lumbar spinal fusion to either a ‘video’ group (one-time oral instruction by a physiotherapist and patients were then issued a video for home exercise), or a ‘café’ group (video regimen with the addition of three café meetings with other fusion-operated patients) or a ‘training’ group (exercise therapy; physiotherapist-guided; two times a week for 8 weeks). Register data of service utilization in the primary health care sector were collected from the time of randomization through 24 months postsurgery. Costs of in-hospital protocols were estimated and the service utilization in the primary health care sector and its cost were analyzed. A significant difference (P=0.023) in number of contacts was found among groups at 2-year follow-up. Within the periods of 3–6 months and 7–12 months postoperatively, the experimental groups required less than half the amount of care within the primary health care sector as compared to the video group (P=0.001 and P=0.008). The incremental costs of the café regimen respectively, the training regimen were compensated by cost savings in the primary health care sector, at ratios of 4.70 (95% CI 4.64; 4.77) and 1.70 (95% CI 1.68; 1.72). This study concludes that a low-cost biopsychosocial rehabilitation regimen significantly reduces service utilization in the primary health care sector as compared to the usual regimen and a training exercise regimen. The results stress the importance of a cognitive element of coping in a rehabilitation program.
Lumbar spinal fusion; Rehabilitation; Primary care; Costs and cost analysis
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.
Pain drawing; Spinal fusion; Dallas Pain Questionnaire; Low Back Pain Rating Scale; Donor site pain; Instrumentation; Randomised clinical trial