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Objective: To examine the effect of a case manager–assisted rehabilitation programme as an add-on to usual physical rehabilitation in patients undergoing lumbar spinal fusion. Design: A randomized controlled trial with a two-year follow-up. Settings: Outpatient clinics of a university hospital and a general hospital. Subjects: In total, 82 patients undergoing lumbar spinal fusion. Interventions: The patients were randomized one-to-one to case manager–assisted rehabilitation (case manager group) or no case manager–assisted rehabilitation (control group). Both groups received usual physical rehabilitation. The case manager–assisted rehabilitation programme included a preoperative meeting with a case manager to determine a rehabilitation plan, postsurgical meetings, phone meetings, and voluntary workplace visits or roundtable meetings. Main measures: Primary outcome was the Oswestry Disability Index. Secondary outcomes were back pain, leg pain, and return to work. Results: Of the 41 patients in the case manager group, 49% were men, with the mean age of 46.1 (±8.7 years). In the control group, 51% were male, with the mean age of 47.4 (±8.9 years). No statistically significant between-group differences were found regarding any outcomes. An overall group effect of 4.1 points (95% confidence interval (CI): –1.8; 9.9) was found on the Oswestry Disability Index, favouring the control group. After two years, the relative risk of return to work was 1.18 (95% CI: 0.8; 1.7), favouring the case manager group. Conclusion: The case manager–assisted rehabilitation programme had no effect on the patients’ functional disability or back and leg pain compared to usual physical rehabilitation. The study lacked power to evaluate the impact on return to work.

Objective: To examine the cost-effectiveness of case manager–assisted rehabilitation as an add-on to usual physical rehabilitation after lumbar spinal fusion, given the lack of any clinical benefits found on analysing the clinical data. Design: Economic evaluation alongside a randomized controlled trial with two-year follow-up. Setting: Patients from the outpatient clinics of a university hospital and a general hospital. Subjects: A total of 82 lumbar spinal fusion patients. Interventions: Patients were randomized one-to-one to case manager–assisted rehabilitation programme as an add-on to usual physical rehabilitation or to usual physical rehabilitation. Main measures: Oswestry Disability Index and EuroQol 5-dimension. Danish preference weights were used to estimate quality-adjusted life years. Costs were estimated from micro costing and national registries. Multiple imputation was used to handle missing data. Costs and effects were presented with means (95% confidence interval (CI)). The incremental net benefit was estimated for a range of hypothetical values of willingness to pay per gain in effects. Results: No impact of case manager–assisted rehabilitation on the Oswestry Disability Index or estimate quality-adjusted life years was observed. Intervention cost was Euros 3984 (3468; 4499), which was outweighed by average reductions in inpatient resource use and sickness leave. A cost reduction of Euros 1716 (–16,651; 20,084) was found in the case manager group. Overall, the probability for the case manager–assisted rehabilitation programme being cost-effective did not exceed a probability of 56%, regardless of willingness to pay. Sensitivity analysis did not change the conclusion. Conclusion: This case manager–assisted rehabilitation programme was unlikely to be cost-effective.

Clinical research has documented that cage subsidence and the loss of balance correction is a significant complication related to spinal fusion. Subsidence is a multifactorial complication, where implant design is one important element. The aim of the study is to compare the rigidity and bone–implant relative motion of segments treated with either a conventional one-piece ALIF cage versus a two-piece ALIF cage, which adapts in situ and permits 7°–21° of lordosis. Seven lumbosacral (L3-S1) human cadaver specimens were tested in a universal spine tester in the intact condition, the specimens instrumented with a two-piece ALIF cage (Statur®-L, FBC Device, Denmark) and a one-piece ALIF cage (Pezo™-A, Ulrich GmbH & Co. KG., Germany), both supplemented with a pedicle screw system using pure moments of ±7.5 Nm in three principal motion directions. For assessment of the bone–implant interface, fluoroscopic videos were captured during motion and 3D motion was measured using an optical motion capturing system. Significantly less motion at the implant–endplate interface was found for the two-piece cage (1.0° ± 0.6°) in comparison to the one-piece cage (4.2° ± 1.7°) in flexion/extension. No significant differences in segment rigidity were found between the one-piece and two-piece cages in the 360° setup, while both configurations significantly reduced the range of motion compared to the intact condition (p

The number of patients undergoing lumbar spinal fusion procedures (LSF) has risen in recent years, but only few studies have examined different rehabilitation strategies for this patient group.To evaluate the impact of initiating rehabilitation either 6 or 12 weeks after a LSF based on the patients' physical performance using the 6-min walking test (6MWT) and the Åstrand Fitness test (AF-test) as measurement.A multicentre RCT including 82 patients with degenerative disc diseases undergoing LSF randomly assigned to initiate rehabilitation either 6 or 12 weeks after surgery. Both groups received the same group-based rehabilitation. The main outcome measures were the 6MWT and the AF-test, secondarily questionnaire-based measures. Follow-up at baseline as well as at 3, 6 and 12 months after surgery.Comparing the two groups no statistically significant difference was found in walking distance or fitness over time. In both groups, the patients achieved an overall increase in walking distance (p0.01), but no improvement in fitness. The 6MWT showed significant correlation (-0.37 to -0.59) with the questionnaire-based outcome measures (p0.01). The AF-test did not correlate to either the 6MWT or any of the questionnaire-based outcome measures.No difference was found in the effect of initiating rehabilitation either 6 or 12 weeks after LSF on the patients' physical performance in terms of fitness and walking distance. The 6MWT showed fair to moderate correlation to the questionnaire-based outcome measures. The AF-test showed no significant independent value, and we question its use in LSF patients.

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.

Background and Purpose Despite a successful surgical procedure, deficits in muscle strength and physical function are documented 1–2 years after total hip replacement (THR). There is a lack of evidence concerning which rehabilitation strategy is the most effective after THR. The purpose of this pilot study was to investigate the feasibility of an early-initiated intensified, home-based training regime and to form the basis of future studies with regard to exercises, outcome measures and power calculations. Methods The trial is a single-blinded, cluster-randomized controlled trial performed at an orthopaedic physiotherapy department in a public hospital in Denmark. A consecutive sample of 46 patients undergoing primary THR surgery for osteoarthritis between September 2008 and January 2009 was included. Forty-four patients completed the trial (96% follow-up). Participants were randomly assigned to an intervention group (IG, n = 23) receiving 12 weeks of intensified exercises (e.g. rubber band resistance) or a control group (CG, n = 21) receiving standard rehabilitation exercises without external resistance. The outcome measurements were maximal gait speed, isometric hip abductor muscle strength, one-legged stance, health-related quality of life (EuroQol-5 Dimensions), patient satisfaction, and patient-evaluated function, stiffness and pain (Western and Ontario McMasters University Osteoarthritis Index). Results There were significant increases in both groups in all the measurements during the 12 weeks of exercises. All participants in the IG were satisfied or very satisfied with the exercises compared with 85% in the CG (P = 0.095). In the IG, four participants (17.4%) had difficulties when performing the intensified exercises at home. Hip abduction strength was significantly weaker in the leg operated compared with the leg not operated on after the intervention in both groups (P

Study Design. A cost-effectiveness analysis conducted alongside a randomized clinical trial. Objective. To assess the cost-effectiveness of a preoperative cognitive-behavioral therapy (CBT) intervention compared to usual care for patients undergoing lumbar spinal fusion surgery (LSF). Summary of Background Data. The clinical effectiveness of a preoperative CBT intervention for patients undergoing LSF has been investigated in a randomized clinical trial. Economic evaluation is however essential for decision makers to make informed choices regarding allocation of scarce resources. Methods. 90 patients undergoing LSF were randomly allocated to usual care (control group) or usual care plus a preoperative CBT intervention (CBT group). Outcome parameters included quality-adjusted life years (QALY), based on the EQ-5D, and pain-related disability, based on the Oswestry disability index (ODI). Health care use and productivity loss were estimated from national registers. Results. One year after LSF the estimated QALY was significantly better for the CBT group with 0.710 (95% CI 0.670; 0.749) versus 0.636 (95% CI 0.5573; 0.687). For the ODI, the CBT group reported significantly larger disability reductions at 3 months (P =0.003) and 6 months (P =0.047), but not at 1 year (P=0.082).There was no difference in the overall costs of the two groups (-s89 (95% CI-12,080; 11,902)), leading to a 70% probability of the CBT intervention being cost-effective at a willingness-to-pay of s40,000 for one additional QALY. For an additional gain of 15 ODI points the probability was 90% at a threshold of s10,000. These results remained largely unaffected by relevant sensitivity analyses, confirming the robustness of findings. Conclusion. Preoperative CBT appears to be more effective and cost neutral when considering the overall health care sector and labor market perspective, supporting the implementation of preoperative CBT in the course of treatment for LSF surgery in a Danish context.

Background The surface texture, localization, and magnitude of the surface material applied to the femoral stem can facilitate bone ingrowth and influence the survival of total hip arthroplasties. Clinical and radiographic studies have shown superior bone ingrowth in proximally porous-coated stems with a diaphyseal grit-blasted surface in comparison to a smooth diaphyseal surface. Surface textures—especially porous surface material—have been suggested to have a sealing effect against migration of polyethylene debris along the implant-bone interface and to reduce the inflammatory response, leading to a prolonged implant survival. Patients and methods Between 2004 and 2006, we conducted a randomized, controlled trial (RCT) involving 50 patients with non-inflammatory arthritis. They received either a distally tapered, extended coated stem or a straight, proximally coated stem. During surgery, tantalum markers were inserted into the greater and lesser trochanter. Implant migration was evaluated at 3, 12, and ...

Udgivelsesdato: 2009-Oct-1 STUDY DESIGN: Randomized, controlled, multi-center trial. OBJECTIVE: To investigate the effect of direct current (DC) electrical stimulation on functional and clinical outcome after lumbar spinal fusion in patients older than 60 years. SUMMARY OF BACKGROUND DATA: Older patients have increased complication rates after spinal fusion surgery. Treatments which have the possibility of enhancing functional outcome and fusion rates without lengthening the procedure could prove beneficial. DC-stimulation of spinal fusion has proven effective in increasing fusion rates in younger and "high risk" patients, but functional outcome measures have not been reported. METHODS: A randomized, clinical trial comprising 5 orthopedic centers. The study included a total of 107 patients randomized to uninstrumented posterolateral lumbar spinal fusion with or without DC-stimulation. Functional outcome was assessed using Dallas Pain Questionnaire, SF-36, Low Back Pain Rating Scale pain index, and walking distance. RESULTS: Follow-up after 1 year was 95/107 (89%). DC-stimulated patients had significant better outcome in 3 of 4 categories in the Dallas Pain Questionnaire, better SF-36 scores (not significantly), but no difference in pain scores were observed. Median walking distance at latest follow-up was better in the stimulated group (not significant). Walking distance was significantly associated with functional outcome. There was no difference in any of the functional outcome scores between patients who experienced a perioperative complication and those without complications. CONCLUSION: The achievement of a good functional outcome was heavily dependent on the obtained walking distance. DC-stimulated patients tended to have better functional outcome as compared to controls. No negative effects of perioperative complications could be observed on the short-term functional outcome.

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.

Study design A randomized clinical trial including 90 patients. Objective To examine the effect of a preoperative cognitive-behavioral intervention (CBT) for patients undergoing lumbar spinal fusion (LSF) surgery. Summary of background data Few published studies have looked at the potential of rehabilitation to improve outcomes after LSF. Rehabilitation programs using CBT are recommended. Furthermore, initiating interventions preoperatively seems beneficial, but only limited data exist in the field of spine surgery. Methods Patients with degenerative disc disease or spondylolisthesis undergoing LSF were randomized to usual care (control group) or preoperative CBT and usual care (CBT group). Primary outcome was change in Oswestry Disability Index from baseline to 1-year follow-up. Secondary outcomes were catastrophizing, fear avoidance belief, work status, and back and leg pain. Results At 1-year follow-up, there was no statistically significant difference between the CBT group and the control group in Oswestry Disability Index score (P = 0.082). However, the CBT group had achieved a significant reduction of -15 points (-26; -4) already at 3 months (between group difference P = 0.003), and this reduction was maintained throughout the year. There were no differences between groups at 1-year follow-up with regard to any of the secondary outcomes. Conclusion Participating in a preoperative CBT intervention in addition to usual care did not produce better outcomes at 1-year follow-up for patients undergoing LSF. Although the reduction in disability was achieved much faster in the CBT group, resulting in a significant difference between groups already 3 months after surgery, it did not translate into a faster return to work. Our findings support the need for further research into the use of targeted rehabilitation interventions among patients with elevated levels of catastrophizing and fear avoidance beliefs. Level of evidence 2.

A retrospectively designed long-term follow-up study of adolescent idiopathic scoliosis (AIS) patients who had completed treatment, of at least 2 years, by means of brace, surgery, or both brace and surgery. This study is to assess the outcome after treatment for AIS by means of the Scoliosis Research Society Outcome Instrument 24 (SRS 24). One hundred and eighteen AIS patients (99 females and 19 males), treated at the Aarhus University Hospital from January 1, 1987 to December 31, 1997, were investigated with at least 2 years follow-up at the time of receiving a posted self-administered questionnaire. Forty-four patients were treated with Boston brace (B) only, 41 patients had surgery (S), and 33 patients were treated both with brace and surgery (BS). The Cobb angles of the three treatment groups did not differ significantly after completed treatment. The outcome in terms of the total SRS 24 score was not significantly different among the three groups. B patients had a significantly better general (not treatment related) self-image and higher general activity level than the total group of surgically treated patients, while surgically treated patients scored significantly better in post-treatment self-image and satisfaction. Comparing B with BS we found a significantly higher general activity level in B patients, while the BS group had significantly higher satisfaction. There were no significant differences between BS and S patients in any of the domain scores. All treatment groups scored “fair or better” in all domain scores of the SRS 24 questionnaire, except in post-treatment function, where all groups scored worse than “fair”. Improvement of appearance by means of surgical correction increases mean scores for post-treatment self-image and post-treatment satisfaction. Double-treatment by brace and surgery does not appear to jeopardize a good final outcome.

UNLABELLED Chronic low back pain (CLBP) has become one of the most common causes of disability in adults under 45 years of age and is consequently one of the most common reasons for early retirement in industrialised societies. Accordingly, CLBP represents an expensive drain on society's resources and is a very challenging area for which a consensus for rational therapy is yet to be established. The spinal fusion procedure was introduced as a treatment option for CLBP more than 70 years ago. However, few areas of spinal surgery have caused so much controversy as spinal fusion. The literature reveals divergent opinions about when fusion is indicated and how it should be performed. Furthermore, the significance of the role of postoperative rehabilitation following spinal fusion may be underestimated. There exists no consensus on the design of a program specific for rehabilitation. Ideally, for any given surgical procedure, it should be possible to identify not only possible complications relative to a surgical procedure, but also what symptoms may be expected, and what pain behaviour may be expected of a particular patient. The overall aims of the current studies were: 1) to introduce patient-based functional outcome evaluation into spinal fusion treatment; 2) to evaluate radiological assessment of different spinal fusion procedures; 3) to investigate the effect of titanium versus stainless steel pedicle screws on mechanical fixation and bone ingrowth in lumbar spinal fusion; 4) to analyse the clinical and radiological outcome of different lumbar spinal fusion techniques; 5) to evaluate complications and re-operation rates following different surgical procedures; and 6) to analyse the effect of different rehabilitation strategies for lumbar spinal fusion patients. The present thesis comprises 9 studies: 2 clinical retrospective studies, 1 clinical prospective case/reference study, 5 clinical randomised prospective studies and 1 animal study (Mini-pigs). In total, 594 patients were included in the investigation from 1979 to 1999. Each had prior to inclusion at least 2 years of CLBP and had therefore been subjected to most of the conservative treatment leg pain, due to localized isthmic spondylolisthesis grades I-II or primary or secondary degeneration. PATIENT-BASED FUNCTIONAL OUTCOME: Patients' self-reported parameters should include the impact of CLBP on daily activity, work and leisure time activities, anxiety/depression, social interests and intensity of back and leg pain. Between 1993 and 2003 approximately 1400 lumbar spinal fusion patients completed the Dallas Pain Questionnaire under prospective design studies. In 1996, the Low Back Pain Rating scale was added to the standard questionnaire packet distributed among spinal fusion patients. In our experience, these tools are valid instruments for clinical assessment of candidates for spinal fusion procedures. RADIOLOGICAL ASSESSMENT It is extremely difficult to interpret radiographs of both lumbar posterolateral fusion and anterior interbody fusion. Plain radiographs are clearly not the perfect media for analysis of spinal fusion, but until new and better diagnostic methods are available for clinical use, radiographs will remain the golden standard. Therefore, the development of a detailed reliable radiographic classification system is highly desirable. The classification used in the present thesis for the evaluation of posteroalteral spinal fusion, both with and without instrumentation, demonstrated good interobserver and intraobserver agreement. The classification showed acceptable reliability and may be one way to improve interstudy and intrastudy correlation of radiologic outcomes after posterolateral spinal fusion. Radiology-based evaluation of anterior lumbar interbody fusion is further complicated when cages are employed. The use of different cage designs and materials makes it almost impossible to establish a standard radiological classification system for anterior fusions. BONE-SCREW INTERFACE: Mechanical binding at the bone-screw interface was significantly greater for titanium pedicle screws than it was for stainless steel. This could be explained by the fact that the titanium screws had superior bone on-growth. There was no correlation between screw removal torques and pull-out strength. Clinically, the use of titanium and titanium-alloy pedicle screws may be preferable for osteoporotic patients and those with decreased osteogenesis. OUTCOME The present series of studies observed significant long-term functional improvement for approximately 70% of patients who had undergone lumbar spinal fusion procedure. Solid fusion as determined from radiographs ranged from 52% to 92% depending on the choice of surgical procedure. The choice of surgical procedure should relate to the diagnosis, as patients with isthmic spondylolisthesis (Grades I and II) are best served with posterolateral fusion without instrumentation, and patients with disc degeneration seem to gain most from instrumented posterolateral fusion or circumferential fusion. COMPLICATIONS The number of perioperative complications increased with the use of pedicle screw systems to support posterolateral fusions and increased further with the use of circumferential fusions. There was no significant association between outcome result and perioperative complications. The risk of reoperation within 2 years after the spinal fusion procedure was, however, significantly lower for those who had received circumferential fusion in comparison to posterolateral fusion with instrumentation. Furthermore, the risk of non-union was found to be significantly lower for patients who had received circumferential fusion as compared to posterolateral fusion with and without instrumentation. The complications of sexual dysfunction and fusion at non-intended levels were found to be significant but without influence on the overall outcome. REHABILITATION The patients in the Back-cafe group performed a succession of many daily tasks significantly better and moreover had less pain compared with both the Video and Training groups 2 years after lumbar spinal fusion. The Video group had significantly greater treatment demands outside the hospital system. This study demonstrates the importance of the inclusion of coping schemes and questions the role of intensive exercises in a rehabilitation program for spinal fusion patients.

STUDY DESIGN: A prospective, randomized, clinical study with a 2-year follow-up.OBJECTIVES: To analyze the effect of three different rehabilitation strategies for lumbar spinal fusion patients.SUMMARY OF BACKGROUND DATA: Fifteen percent to 40% of lumbar spinal fusion patients are not expected to improve significantly over a 2-year period. Optimization of present forms of rehabilitation could possibly further improve the outcome.MATERIALS AND METHODS: Between 1996 and 1999, 90 patients who had undergone lumbar spinal fusion were 3 months after surgery randomized to one of three different rehabilitation groups. Video group participants watched a video of exercises for training and were subsequently and only once provided instruction regarding their use. The back-café group was provided the same program as the video group, but as a supplement met with a back-café with other fusion-operated patients three times over an 8-week period. The training group was provided physical therapy training twice weekly for 8 weeks. Functional outcome was evaluated at 6, 12, and 24 months after surgery by use of the low back pain rating scale and a questionnaire covering daily functions, work status, and a patient's contact with the primary sector.RESULTS: By 2-year follow-up, the back-café and video groups had less pain compared with the training group (P < 0.03). The back-café group was better at performing daily functions such as carrying bags of market items (P < 0.01), getting up from a chair (P < 0.01), and ascending staircases (P < 0.01) compared with the video and training groups. More in the back-café group resumed working after surgery compared with the two other groups (P < 0.04). The video group had significantly more contacts with general practitioners, physical therapists, and so on compared with the back-café and training groups (P < 0.001).CONCLUSION: The patients in the back-café group were significantly better at accomplishing a succession of daily tasks compared with the video and training groups 2 years after lumbar spinal fusion. At the 2-year follow-up the training group had a significant pain problem compared with the video and back-café groups. The video group had significantly more treatment demands outside the hospital system. This study demonstrates the relevance of the inclusion of coping schemes and questions the role of intensive exercises in a rehabilitation program for spinal fusion patients.

In vitro cultures of human primary osteoblast-like cells provide a model for studying cellular mechanisms associated with human bone biology. We investigated in vitro osteoblast-like cell metabolism as a method for predicting the occurrence of spinal fusion in the individual patient. A bone biopsy was taken from the iliac crest of 50 patients, median age 49 (23-77) years, who were undergoing lumbar spine fusion. First-passage osteoblast-like cells were established by the bone-tissue-explant method. We then estimated 3H-thymidine incorporation, alkaline phosphatase activity and procollagen I production. Fusion rates were evaluated at the 1-year follow-up. Primary human osteoblast-like cell cultures showed an age-dependent decline in their capacity for cellular outgrowth and expression of alkaline phosphatase, which suggested a useful biological response pattern of the osteoblast culture. However, such cultures were unsatisfactory as an in vitro tool for predicting fusion capacity.

STUDY DESIGN: A prospective randomized clinical study with a 2-year follow-up period was conducted.OBJECTIVE: To analyze the effects of circumferential fusion using ALIF radiolucent carbon fiber cages and titanium posterior instrumentation on functional outcome, fusion rate, complications, and lumbar lordosis.SUMMARY OF BACKGROUND DATA: Circumferential fusion has become a common procedure in lumbar spine fusion, both as a primary and salvage procedure. However, the claimed advantages of ALIF plus PLF over conventional PLF lack scientific documentation.METHODS: From April 1996 through November 1999, a total of 148 patients with severe chronic low back pain were randomly selected for either posterolateral lumbar fusion with titanium CD-Horizon (posterolateral group) or circumferential fusion with a ALIF Brantigan cage plus posterior instrumentation. The Dallas Pain Questionnaire (DPQ), the Low Back Pain Rating Scale (LBPR), and a questionnaire concerning work status assessed their outcomes.RESULTS: Both groups showed highly significant improvement in all four categories of life quality (DPQ) as well as in the back pain and leg pain index (LBPR), as compared with preoperative status. There was a clear tendency toward better overall functional outcome for patients with the circumferential procedure ( < 0.08), and this patient group also showed significantly less leg pain at the 1-year follow-up evaluation ( < 0.03) and less peak back pain at 2 years ( < 0.04). Sagittal lordosis was restored and maintained in the circumferential group ( < 0.01). The circumferential fusion patients showed a higher posterolateral fusion rate (92%) than the posterolateral group (80%)( < 0.04). The repeat operation rate including implant removal was significantly lower in the circumferential group (7%) ( < 0.009) than in the posterolateral group (22%).CONCLUSIONS: Circumferential lumbar fusion restored lordosis, provided a higher union rate with significantly fewer repeat operations, showed a tendency toward better functional outcome, and resulted in less peak back pain and leg pain than instrumented posterolateral fusion. The clinical perspective of the current study implies a recommendation to favor circumferential fusion as a definitive surgical procedure in complex lumbar pathology involving major instability, flatback, and previous disc surgery in younger patients, as compared with posterolateral fusion with pedicle screws alone.

The ideal rehabilitation strategy following lumbar spinal fusion surgery has not yet been established. This paper is a study protocol, describing the rationale behind and the details of a cognitive-behavioural rehabilitation intervention for lumbar spinal fusion patients based on the best available evidence. Predictors of poor outcome following spine surgery have been identified to provide targets for the intervention, and the components of the intervention were structured in accordance with the cognitive-behavioural model. The study aims to compare the clinical and economical effectiveness of a cognitive-behavioural rehabilitation strategy to that of usual care for patients undergoing lumbar spinal fusion surgery. The study is a randomized clinical trial including 96 patients scheduled for lumbar spinal fusion surgery due to degenerative disease or spondylolisthesis. Patients were recruited in the period October 2011 to July 2013, and the follow-up period is one year from date of surgery. Patients are allocated on a 1:2 ratio (control: intervention) to either treatment as usual (control group), which implies surgery and the standard postoperative rehabilitation, or in addition to this, a patient education focusing on pain behaviour and pain coping (intervention group). It takes place in a hospital setting, and consists of six group-based sessions, managed by a multidisciplinary team of health professionals. The primary outcomes are disability (Oswestry Disability Index) and sick leave, while secondary outcomes include coping (Coping Strategies Questionnaire), fear-avoidance belief (Fear Avoidance Belief Questionnaire), pain (Low Back Pain Rating Scale, pain index), mobility during hospitalization (Cumulated Ambulation Score), generic health-related quality of life (EQ-5D) and resource use. Outcomes are measured using self report questionnaires, medical records and national registers. It is expected that the intervention can provide better functional outcome, less pain and earlier return to work after lumbar spinal fusion surgery. By combining knowledge and evidence from different knowledge areas, the project aims to provide new knowledge that can create greater consistency in patient treatment. We expect that the results can make a significant contribution to development of guidelines for good rehabilitation of patients undergoing lumbar spinal fusion. Current Controlled Trials ISRCTN42281022 .

STUDY DESIGN: A review of the smoking habits in 426 patients who had been followed prospectively for 2 years after a lumbar spinal fusion procedure was conducted.OBJECTIVE: To analyze the effect of pre- and postoperative smoking on clinical and functional outcome after lumbar spinal fusion.SUMMARY OF BACKGROUND DATA: Several animal models have shown a negative effect of nicotine on spinal fusion. At this writing, the clinical effect of nicotine on spinal fusion has not been fully clarified.METHODS: The study comprised 426 patients who underwent lumbar spinal fusion between 1993 and 1997. These patients received a mailed questionnaire regarding their tobacco consumption before and after their surgery. All other data, including preoperative clinical and functional status, were collected prospectively during a 2-year follow-up period. To assess functional outcome, the Dallas Pain Questionnaire was used.RESULTS: The questionnaire was answered by 396 patients (93%). Of these patients, 54.5% (20% more than the background population) were smokers before the operation. Smoking of more than 10 cigarettes daily before the operation and attempted fusion at two or more levels increased the risk of nonunion: odds ratio, 2.01 (P < 0.016) and odds ratio, 3.03 (P < 0.001), respectively. Smoking cessation increased fusion rates to near those of nonsmokers. Smoking had no influence on functional outcome, as assessed by the Dallas Pain Questionnaire, but preoperative smoking predicted a negative answer to the question "Would you undergo the same treatment again, now that you know the result?" (odds ratio, 1.65; P < 0.054).CONCLUSIONS: Smoking was shown to have a negative effect on fusion and overall patient satisfaction, but no measurable influence on the functional outcome as assessed by the Dallas Pain Questionnaire.

In a prospective randomized study, we evaluated the risk of lumbar posterolateral spinal fusion at an unintended level due to bone graft migration. 130 patients underwent fusion supplemented by pedicle screw fixation (Cotrell-Dubousset, 64 patients) or uninstrumented fusion (66 patients). This was assessed by two independent observers on antero-posterior, and lateral radiographs taken 1 year after surgery. All patients had ben operated on at the preoperatively planned levels. Both observers agreed that fusion had taken place at an unintended level in 19 cases (14%). We found a tendency towards a higher risk of this "complication" when using supplementary pedicle screw fixation. The functional outcome, assessed by the Dallas Pain Questionnaire and the Low Back Pain Rating scale, was similar in patients having fusion at an unintended level and in patients fused only at the intended levels. There was no difference between the two groups concerning reoperation rates, postoperative smoking or social status. We conclude that unintended fusion occurs and tends to be commoner with the use of pedicle screw instrumentation. However, this complication seems not to affect the functional outcome if fusion has taken place at the intended level.

Several types of pedicle screw systems have been utilized to augment lumbar spine fusion. The majority of these systems are made of stainless steel (Ss), but titanium-alloy (Ti-alloy) devices have recently been available on the market. Ti-alloy implants have several potential advantages over Ss ones. High bioactivity and more flexibility may improve bone ingrowth and mechanical fixation, and the material also offers superior magnetic resonance imaging (MRI) and computed tomography (CT) resolution and significantly less signal interference. However, no data are available from loaded spinal constructs regarding bony ingrowth and mechanical fixation. The aim of this study was to analyse the effect of Ti-alloy versus Ss pedicle screws on mechanical fixation and bone ingrowth in a loaded mini-pig model. Eighteen adult mini-pigs underwent total laminectomy and posterolateral spinal fusion at L3-L4, and were randomly selected to receive either Ss (n = 9) or Ti (n = 9) pedicle screw devices. In both groups, the device used was compact Cotrel-Dubousset instrumentation (Sofamore Danek) of an identical size and shape. The postoperative observation time was 3 months. Screws from L3 were used for histomorphometric studies. Mechanical testing (torsional tests and pull-out tests) was performed on the screws from L4. The Ti screws had a higher maximum torque (P < 0.05) and angular stiffness (P < 0.07), measured by torsional testing. In the pull-out tests, no differences were found between the two groups with respect to the maximum load, stiffness and energy to failure. No correlation between removal torque and the pull-out strength was found (r = 0.1). Bone ongrowth on Ti was increased by 33% compared with Ss (P < 0.04), whereas no differences in bone volume around the screws were shown. Mechanical binding at the bone-screw interface was significantly greater for Ti pedicle screws than for Ss, which was explained by the fact that Ti screws had a superior bone ongrowth. There was no correlation between the screw removal torque and the pull-out strength, which indicates that the peripheral bone structure around the screw was unaffected by the choice of metal.

The capacity of the individual patient to initiate osteoblast proliferation as a predictor for successful lumbar spinal fusion has not yet been reported. The objectives of this study were, first, to analyze the relationship between in vitro osteoblast proliferation and clinical bony fusion in the individual patient in order to predict the fusion outcome and, second, to measure the effect of preoperative tobacco smoking on osteoblast proliferation. Sixty-one patients (mean age 46 years) underwent posterolateral lumbar fusion in the period 1994-1995. Thirty-eight patients received CD pedicle screw implants and 23 received posterolateral fusions alone. During surgery, autogenous iliac bone was harvested and 1 g of trabecular bone without blood or bone marrow was then isolated for cell culturing. The cultures were classified as excellent (confluence within 4 weeks), good (confluence between 4 and 6 weeks) and poor (no or poor growth). Spine fusion was evaluated by two independent observers from plain anterior- posterior, lateral, and flexion/extension radiographs taken 1 year postoperatively, and the functional outcome was measured by the Dallas Pain Questionnaire (DPQ). Twenty-three patients had excellent, 19 good, and 19 poor in vitro osteoblast proliferation. Bony fusion was obtained in 77% of patients: 83% in the CD instrumentation group and 70% in the non- instrumentation group (NS). There was no significant correlation between osteoblast proliferation and spinal fusion or functional outcomes when analyzing the CD instrumentation and non-instrumentation groups together or separately. Elderly patients had a significantly poorer osteoblast proliferation than younger patients (P < 0.008). Preoperative tobacco consumption had no discernible effect on osteoblast proliferation, and no correlation between smoking and fusion was found. Further refinement of autologous osteoblast culturing may provide a biological tool for selection of patients who require biological enhancement of their bone fusion capacity. The poorer osteoblast proliferation related to advanced age supports the important negative biological influence of age on bony fusion. However, with more sensitive testing and better discrimination, other results are possible - or can in any event not be excluded.

Lumbar spinal fusion is a commonly performed surgical procedure, yet both the indications for its performance and its results remain controversial. It is generally believed that apart from situations where obvious measurable instability exists, a repeat surgical procedure such as spinal fusion does not improve the functional outcome in more than an average of 50% of cases. The aim of this study was to analyse functional outcome after posterolateral lumbar or lumbosacral spinal fusion, comparing primary and salvage procedures. It was designed as a prospective case/referent study with a 2-year follow-up. A total of 39 patients underwent a short posterior fusion with Cotrel-Dubousset (CD) pedicle screw fixation after earlier surgerY of the lumbar spine. Two patients were erroneously omitted from the study at the index, so 37 patients were included in the salvage group. In the same period, 69 patients underwent lumbar fusion with pedicle screw fixation (CD) as primary surgery (referent group). Functional outcome was assessed by means of the Dallas Pain Questionnaire preoperatively and 1 and 2 years postoperatively. Fusion rates were determined by ordinary X-ray evaluation by two independent observers. Patients who had undergone previous spinal surgery had a significant improvement in functional outcome in terms of daily activity, work and leisure-time activities and anxiety/depression. With regard to social functioning, a significantly inferior outcome was found after the salvage procedure. The return-to-work rates at 2 years after surgery were 50% in the salvage group and 53% in the referent group. There was a significant correlation between radiological evaluation of the fusion mass and the functional outcome. The fusion rate was 76% in the salvage group and 72% in the referent group. This study demonstrates that a posterolateral spinal fusion can be effectively used as a salvage procedure. The functional and radiological outcome of the patients with revision surgerY did not differ from those of the group of patients who underwent primary surgery. There was, however a clear indication of inferior social functioning after revision surgery.

STUDY DESIGN A prospective randomized clinical study. OBJECTIVES To evaluate supplementary pedicle screw fixation (Cotrel-Dubousset) in posterolateral lumbar spinal fusion. SUMMARY OF BACKGROUND DATA The rationale behind lumbar fusion is to eliminate pathologic motion to relieve pain. To improve fusion rates and to allow reduction, a rigid transpedicular screw fixation may be beneficial, but the positive effect of this may be counter-balanced by an increase in complications. METHODS The inclusion criteria were severe, chronic low back pain from spondylolisthesis Grades 1 and 2 or from primary or secondary degenerative segmental instability. One hundred thirty patients were randomly allocated to receive no instrumentation (n = 66) or Cotrel-Dubousset instrumentation (n = 64) in posterolateral lumbar fusion. Variables were registered at the time of surgery and at 1 and 2 years after surgery. RESULTS Follow-up was achieved in 97.7% of the patients. Fusion rates deduced from plain radiographs were not significantly different between instrumented and noninstrumented groups. The functional outcome assessed by the Dallas Pain Questionnaire improved significantly in both groups, and there were no significant differences in results between the two groups, except for significantly better (P < 0.06) functional outcome in relation to daily activities in the instrumented group when neural decompression had been performed. The global patients' satisfaction was 82% in the instrumented group versus 74% in the noninstrumented group (not significant). Fixation of instrumentation increased operation time, blood loss, and early reoperation rate significantly. Patients experienced only a few minor postoperative complications; none were major. Two infections appeared in the Cotrel-Dubousset group. Significant symptoms from misplacement of pedicle screws were seen in 4.8% of the instrumented patients. CONCLUSIONS Lumbar posterolateral fusion with pedicle screw fixation increases the operation time, blood loss, and reoperation rate, and leads to a significant risk of nerve injury. The functional outcome improves significantly with high patient satisfaction, with or without instrumentation. No significant differences were observed between the two groups in functional outcome and fusion rate. The only gain in functional outcome from instrumentation was found in the daily activity category in patients with supplementary neural decompression. The results of this study do not justify the general use of pedicle screw fixation alone as an adjunct to posterolateral lumbar fusion.

We have studied the incidence and functional outcome of retrograde ejaculation as a postoperative complication of anterior lumbar interbody fusion. A questionnaire, specifically designed to analyse this problem, has been used over a 6 to 13 year follow-up. Out of 50 men, 41 completed the questionnaire; 2 complained they had permanent retrograde ejaculation after the operation, one stopped ejaculating for 6 months, and thereafter had a 50% reduction. The Dallas pain questionnaire showed that retrograde ejaculation did not have a negative effect on the functional outcome, but male genital dysfunction was a complication of anterior spinal fusion in 8% of cases.

Study design Economic evaluation conducted alongside a randomized controlled trial with 1-year follow-up. Objective To examine the cost-effectiveness of initiating rehabilitation 6 weeks after surgery as opposed to 12 weeks after surgery. Summary of background data In a previously reported randomized controlled trial, we assessed the impact of timing of rehabilitation after a lumbar spinal fusion and found that a fast-track strategy led to poorer functional ability. Before making recommendations, it seems relevant to address the societal perspective including return to work, quality of life, and costs. Methods A cost-effectiveness analysis and a cost-utility analysis were conducted. Eighty-two patients undergoing instrumented lumbar spinal fusion due to degenerative disc disease or spondylolisthesis (grade I or II) were randomized to an identical protocol of 4 sessions of group-based rehabilitation and were instructed in home exercises focusing on active stability training. Outcome parameters included functional disability (Oswestry Disability Index) and quality-adjusted life years. Health care and productivity costs were estimated from national registries and reported in euros. Costs and effects were transformed into net benefit. Bootstrapping was used to estimate 95% confidence intervals (95% CI). Results The fast-track strategy tended to be costlier by €6869 (95% CI, -4640 to 18,378) while at the same time leading to significantly poorer outcomes of functional disability by -9 points (95% CI, -18 to -3) and a tendency for a reduced gain in quality-adjusted life years by -0.04 (95% CI, -0.13 to 0.01). The overall probability for the fast-track strategy being cost-effective does not reach 10% at conventional thresholds for cost-effectiveness. Conclusion Initiating rehabilitation at 6 weeks as opposed to 12 weeks after surgery is on average more costly and less effective. The uncertainty of this result did not seem to be sensitive to methodological issues, and clinical managements who have already adapted fast-track rehabilitation strategies have reason to reconsider their choice. .

Lumbar decompression surgery (LDS) and total hip arthroplasty (THA) are frequently performed in the elderly population, but very little is known about their subsequent physical capacity and participation in leisure activities. Despite similar demographics and comorbidities, it is questionable whether LDS patients achieve equally high levels of physical capacity and quality of life postoperatively as do THA patients. The aim was to compare the physical activity level, participation in leisure activities and related quality of life 1 year after an LDS and THA procedure.Data from 95 THA patients and 83 LDS patients were gathered from questionnaires on self-reported physical activity level, leisure activities and quality of life.LDS and THA patients reported equally moderate levels of physical activity. The median score was 42.3 METs/day (IQR 37.9; 47.7) for the LDS group and 41.0 METs/day (IQR 38.5; 48.5) for the THA group (p = 0.79). Weekly time consumption for leisure activities in the LDS group was a median of 420 min/week (IQR 210; 660) compared to a median of 480 min/week (IQR 240; 870) in the THA group (p = 0.16). Regarding quality of life, LDS patients reported significantly worse Euroqol Five Dimensions scores with a median value of 0.740 (IQR 0.68; 0.82) compared to THA patients' median of 0.824 (IQR 0.72; 1.0), p0.001.Despite being equally physically active and engaged in leisure activities, LDS patients did not achieve a quality of life comparable to that of THA patients 1 year postoperatively.

Background:Medial tibial stress syndrome (MTSS) is a common diagnosis. Several studies have demonstrated that excessive static navicular drop (ND) is related to the diagnosis. However, no studies have yet investigated ND and the velocity of ND during dynamic conditions. The aim of this study was to evaluate ND characteristics in patients with MTSS in dynamic and static conditions.Methods:In a case-control study, 14 patients diagnosed as having MTSS were included from an orthopedic outpatient clinic. A control group consisting of 14 healthy participants was matched regarding age, sex, and typical sporting activity. Navicular drop was evaluated during treadmill walking by a two-dimensional video analysis. Static foot posture, static ND, dynamic ND (dND), and velocity of dND were compared.Results:The two groups were comparable in relation to age, sex, height, weight, and foot size. No significant difference was found in static foot posture. Static ND showed a mean difference of 1.7 mm between the groups (P= .08). During treadmill walking, patients with MTSS had, on average, a 1.5-mm-larger dND (P=.004) and a 2.4-mm/sec-larger mean velocity of dND (P= .03).Conclusions:Patients with MTSS display a larger ND and a higher ND velocity during treadmill walking. Increased ND velocity may be important to this condition. Future studies should include velocity of dND to investigate the mechanisms of dND in relation to overuse injuries. (J Am Podiatr Med Assoc 102(3): 205–212, 2012)

Study design A multicenter randomized clinical trial including 82 patients. Objective To examine the effect of early initiation of rehabilitation after instrumented lumbar spinal fusion. Summary of background data Lumbar spinal fusion has been performed for more than 70 years. Yet, few studies have examined patients' subsequent rehabilitation. Group-based rehabilitation is both efficient and cost-effective in rehabilitation of lumbar spinal fusion patients. Methods Patients with degenerative disc diseases undergoing instrumented lumbar spinal fusion were randomly assigned to initiate their rehabilitation 6 weeks (6-wk group) or 12 weeks after lumbar spinal fusion (12-wk group). Both groups received the same group-based rehabilitation. Primary outcome was the Oswestry Disability Index. Secondary outcome was the Dallas Pain Questionnaire, the Low Back Pain Rating Scale, and absence from work. Wilcoxon rank-sum test was used to compare the groups in terms of differences from baseline to 6 months and 1-year follow-up. Results are presented in median with 25th and 75th percentiles. Results According to the Oswestry Disability Index, at 1-year follow-up, the 6-week-group had a median reduction of -6 (-19; 4) compared with -20 (-30;-7) in the 12-week group (P, 0.05). The Dallas Pain Questionnaire showed overall the same tendency, and within daily activities were significantly reduced in favor of the 12-week group (P, 0.05). For back pain, the 6-week group had a median reduction of -2.2 (-3.0; -0.7) similar with -3.3 (-4.7; -1.7) in the 12-week group (P, 0.05). The results at 6 months of follow-up were similar. No difference was found according to return to work 1 year postsurgery. Conclusion Early start of rehabilitation (6 wk vs. 12 wk) after lumbar spinal fusion resulted in inferior outcomes. The improvements in the 12-week group were 4 times better than that in the 6-week group, indicating that the start-up time of rehabilitation is an important contributing factor for the overall outcome.

Although lumbar spinal fusion has been performed for more than 70 years, few studies have examined rehabilitation strategies for spinal fusion patients, and there is only sparse information about the patient’s activity level after surgery. The Canadian Occupational Performance Measure (COPM) is a standardized semi-structured interview, developed to identify patients’ problems in relation to activities of daily living (ADL). The COPM has neither been examined in a randomised clinical study nor employed in relation to lumbar spinal fusion patients. We aimed to examine whether or not the use of the semi-structured interview COPM during in-hospital rehabilitation could: (1) identify more ADL-related problems of importance to the patients after discharge from the hospital, (2) enhance the patients’ ADL performance after discharge from hospital Eighty-seven patients undergoing a lumbar spinal fusion caused by degenerative diseases were randomly assigned to either use of the COPM or to standard treatment. Use of the COPM during hospitalization helped in identifying more ADL problems encountered by patients during the first 3 months post-discharge period as COPM served to identify more treatment goals and plans of action. Use of the COPM had no impact on the patients’ ADL performance, and the difference is so small that COPM may be of little clinical consequence.

Despite a successful surgical procedure, deficits in muscle strength and physical function are documented 1-2 years after total hip replacement (THR). There is a lack of evidence concerning which rehabilitation strategy is the most effective after THR. The purpose of this pilot study was to investigate the feasibility of an early-initiated intensified, home-based training regime and to form the basis of future studies with regard to exercises, outcome measures and power calculations.The trial is a single-blinded, cluster-randomized controlled trial performed at an orthopaedic physiotherapy department in a public hospital in Denmark. A consecutive sample of 46 patients undergoing primary THR surgery for osteoarthritis between September 2008 and January 2009 was included. Forty-four patients completed the trial (96% follow-up). Participants were randomly assigned to an intervention group (IG, n = 23) receiving 12 weeks of intensified exercises (e.g. rubber band resistance) or a control group (CG, n = 21) receiving standard rehabilitation exercises without external resistance. The outcome measurements were maximal gait speed, isometric hip abductor muscle strength, one-legged stance, health-related quality of life (EuroQol-5 Dimensions), patient satisfaction, and patient-evaluated function, stiffness and pain (Western and Ontario McMasters University Osteoarthritis Index).There were significant increases in both groups in all the measurements during the 12 weeks of exercises. All participants in the IG were satisfied or very satisfied with the exercises compared with 85% in the CG (P = 0.095). In the IG, four participants (17.4%) had difficulties when performing the intensified exercises at home. Hip abduction strength was significantly weaker in the leg operated compared with the leg not operated on after the intervention in both groups (P 0.01).This pilot study indicates that the majority of THR patients tolerated early-initiated intensified exercises without additional pain and with high patient satisfaction. It seems that some of the patients need supervision to perform intensified exercises.

Randomized clinical trial.To analyze the long-term clinical impact of anterior column support on sagittal balance after lumbar spinal fusion.Several investigators have stressed the importance of maintaining sagittal balance in relation to spinal fusion to avoid lumbar 'flat back,' accelerated adjacent segment degeneration, pain, and inferior functional outcome. Only limited evidence exists on how sagittal alignment affects clinical outcome. Anterior lumbar interbody fusion combined with posterolateral fusion has been proved superior to posterolateral fusion alone regarding outcome and cost-effectiveness. No randomized controlled trial has been published analyzing the effect of anterior support on radiographic measurements of sagittal balance.Between 1996 and 1999, 148 patients with severe chronic low back pain were randomly selected for posterolateral lumbar fusion plus anterior support (PLF + ALIF) or posterolateral lumbar fusion. A total of 92 patients participated. Sagittal balance parameters were examined on full lateral radiographs of the spine: pelvic incidence (PI), pelvic tilt (PT), sacral slope, thoracic kyphosis, lumbar lordosis, and positioning of C7 plumb line. The type of lumbar lordosis was evaluated and outcome assessed by Oswestry Disability Index (ODI).Follow-up rate was 74%. Sagittal balance parameters were similar between randomization groups. None of the parameters differed significantly between patients with an ODI from 0 to 40 and patients with ODI over 40. Balanced patients had a significantly superior outcome as measured by ODI (P0.05) compared with unbalanced patients.No difference in the investigated sagittal balance parameters was seen between patients treated with PLF + ALIF or posterolateral fusion alone. Lumbar lordosis and type of lordosis correlated with outcome but could not explain the superior outcome in the group with anterior support. Whether sagittal balance and anterior support during fusion provide a protective effect on adjacent motion segments remains unclear.

Study design Randomized controlled trial. Objective To analyze long-term adjacent segment degeneration (ASD) after lumbar fusion on magnetic resonance imaging and compare randomization groups with and without anterior column support. Summary of background data ASD can be a long-term complication after fusion. The prevalence and the cause of ASD are not well documented, but ASD are one of the main arguments for introducing the use of motion-preserving techniques as an alternative to fusion. Anterior lumbar interbody fusion combined with posterolateral lumbar fusion (ALIF+PLF) has been proved superior to posterolateral fusion alone regarding outcome and cost-effectiveness. Methods Between 1996 and 1999, 148 patients with severe chronic low back pain were randomly selected for ALIF+PLF or for PLF alone. Ninety-five patients participated. ASD was examined on magnetic resonance imaging with regard to disc degeneration, disc herniation, stenosis, and endplate changes. Disc heights on radiographs taken at index surgery and at long-term follow-up were compared. Outcome was assessed by validated questionnaires. Results The follow-up rate was 76%. ASD was similar between randomization groups. In the total cohort, endplate changes were seen in 26% of the participants and correlated significantly with the presence of disc degeneration and disc herniation. Disc degeneration and dorsal disc herniation were the parameters registered most frequently and were significantly more pronounced at the first adjacent level than at the second and the third adjacent levels. Patients without disc height reduction over time were significantly younger than patients with disc height reduction. Disc degeneration and stenosis correlated significantly with outcome at the first adjacent level. Conclusion The cause of the superior outcome in the group with anterior support is still unclear. Compared with the findings reported in the literature, the prevalence of ASD is likely to be in concordance with the expected changes in a nonoperated symptomatic population and therefore not accelerated by fusion.

We read the article entitled “Alendronate treatment improves bone–pedicle screw interface fixation in posterior lateral spine fusion: an experimental study in a porcine model” by Qingyun Xue et al. with great interest [1]. The purpose of the research was to investigate whether alendronate treatment improves bone–pedicle screw interface fixation in posterior lateral spine fusion. We would like to thank the authors for their innovative and encouraging paper, but we have some concerns about the safety profile of alendronate. The authors advocated wider use of alendronate based on the properties of bisphosphonates for reduction of bone remodelling by inhibition of osteoclastic activity. Normal bone remodelling is linked to new bone formation by the so-called coupling phenomenon. The most effective approach to prevent implant loosening would be to have a positive balance between bone formation and resorption in the active bone-remodelling time period. Alendronate treatment could protect the bone structure from extra resorption while maintaining the bone volume around the screw surface. In fact, prolonged suppression of bone remodelling with alendronate may be associated with a new form of insufficiency fracture of femur [2]. The fracture rate is higher in long-term use than during the first year of therapy, suggesting possible adverse effects on bone [3]. Alendronate inhibits bone resorption by suppressing activity of osteoclasts, and inducing them to undergo apoptosis. While this leads to an increase in bone mineral density (BMD) of patients with osteoporosis, treatment with alendronate has been shown to reduce bone turnover. In humans prolonged administration of bisphosphonates can lead to development of osteopetrosis or marble bone disease [4]. Keeping the above-mentioned facts in mind, authors must warn the orthopaedic community about liberal use of alendronate.

Background context Pain 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. Purpose To 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. Study design Prospective clinical cohort with a minimum of 1-year follow-up. Patient sample One hundred thirty-five patients undergoing lumbar spinal fusion. Fifty-seven men and 78 women, mean age 44 years (range 21–59 years). Outcome measures Dallas Pain Questionnaire (DPQ), Low Back Pain Rating Scale (LBPRS) pain index and patient satisfaction. Minimal clinical important difference was defined for the LBPRS score. Methods Pain 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. Results Thirty-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). Conclusions A nonorganic pain drawing was a significant risk factor for inferior outcome after spinal fusion surgery. The predictive value did not allow for patient selection.

What was formerly known as medicine has now become health care, an amalgam of several disciplines, including health economics. The role of health economics is fairly straightforward, namely to facilitate priority-setting under the objective of maximizing population health. For that purpose, cost-utility evaluations, providing a cost per quality-adjusted life-year (QALY) for different choices, have become popular. If cost-utility evaluations are to be run alongside clinical trials, trialists have to append an instrument for the measurement of generic, preference-based outcomes. The objective of this chapter is to provide some basis for the choice of instrument to assess generic, preference-based outcomes in clinical trials conducted in low back pain.

Biphasic calcium phosphate (BCP) ceramics has a potential advantage as an osteoconductive matrix and has an optimal resorption rate for bone formation. Using BCP ceramics as a bone graft during spinal fusion requires osteogenesis within the material and subsequent bridging between adjacent vertebrae to provide long-term support. Bisphosphonates have been reported to prolong the process of bone healing. The influence of bisphosphonate treatment on bone formation within BCP ceramics in spinal fusion remains unknown. The aim of this study was to evaluate the influence of alendronate on BCP osteogenesis in posterolateral spinal fusion.Posterolateral spinal fusion with pedicle screw fixation was performed at the lumbar spine in twenty-two pigs. BCP ceramics were applied as a bone graft to obtain bone fusion between adjacent transverse processes. Eleven pigs in the treatment group received oral alendronate 10 mg/d for three months postoperatively. Eleven pigs in the control group did not receive treatment with alendronate. All animals underwent posterolateral spinal fusion with BCP ceramics. The fusion rate was evaluated three months after the operation.The fusion rates evaluated by X-ray were 27.3% in the treatment group and 20% in the control group. The fusion rates using histological evaluation were 18.2% in the treatment group and 20% in the control group. The mean volumes of fusion mass were (3.64 +/- 0.86) cm(3) in the treatment group and (4.26 +/- 0.63) cm(3) in the control group. No significant differences were found in either trabecular bone volume or residual BCP volume between treatment and control groups using histological evaluation. The new bone formation within BCP ceramics was greater in the area adjacent to transverse process (P0.01).Oral alendronate with a dose of 10 mg daily do not inhibit bone formation within BCP ceramics or affect the fusion rate in posterolateral spinal fusion from porcine models.

Udgivelsesdato: 2010-Apr-29 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 muA 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/cm(2)) compared to non-smokers (0.517 g/cm(2)) (P = 0.086). Women had lower fusion mass BMD (0.460 g/cm(2)) compared to men (0.552 g/cm(2)) (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 muA 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/cm(2), 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.

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.

Study design Randomized, controlled, multi-center trial. Objective To investigate the effect of direct current (DC) electrical stimulation on functional and clinical outcome after lumbar spinal fusion in patients older than 60 years. Summary of background data Older patients have increased complication rates after spinal fusion surgery. Treatments which have the possibility of enhancing functional outcome and fusion rates without lengthening the procedure could prove beneficial. DC-stimulation of spinal fusion has proven effective in increasing fusion rates in younger and "high risk" patients, but functional outcome measures have not been reported. Methods A randomized, clinical trial comprising 5 orthopedic centers. The study included a total of 107 patients randomized to uninstrumented posterolateral lumbar spinal fusion with or without DC-stimulation. Functional outcome was assessed using Dallas Pain Questionnaire, SF-36, Low Back Pain Rating Scale pain index, and walking distance. Results Follow-up after 1 year was 95/107 (89%). DC-stimulated patients had significant better outcome in 3 of 4 categories in the Dallas Pain Questionnaire, better SF-36 scores (not significantly), but no difference in pain scores were observed. Median walking distance at latest follow-up was better in the stimulated group (not significant). Walking distance was significantly associated with functional outcome. There was no difference in any of the functional outcome scores between patients who experienced a perioperative complication and those without complications. Conclusion The achievement of a good functional outcome was heavily dependent on the obtained walking distance. DC-stimulated patients tended to have better functional outcome as compared to controls. No negative effects of perioperative complications could be observed on the short-term functional outcome.

Paraspinal muscle damage is inevitable during conventional posterior lumbar fusion surgery. Minimal invasive surgery is postulated to result in less muscle damage and better outcome. The aim of this study was to monitor metabolic changes of the paraspinal muscle and to evaluate paraspinal muscle damage during surgery using microdialysis (MD). The basic interstitial metabolisms of the paraspinal muscle and the deltoid muscle were monitored using the MD technique in eight patients, who underwent posterior lumbar fusion surgery (six male and two female, median age 57.7 years, range 37-74) and eight healthy individuals for different positions (five male and three female, age 24.1 +/- 0.8 years). Concentrations of glucose, glycerol, and lactate pyruvate ratio (L/P) in both tissues were compared. In the healthy group, the glucose and glycerol concentrations and L/P were unchanged in the paraspinal muscle when the body position changed from prone to supine. The glucose concentration and L/P were stable in the paraspinal muscle during the surgery. Glycerol concentrations increased significantly to 243.0 +/- 144.1 microM in the paraspinal muscle and 118.9 +/- 79.8 microM in the deltoid muscle in the surgery group. Mean glycerol concentration difference (GCD) between the paraspinal muscle and the deltoid tissue was 124.1 microM (P = 0.003, with 95% confidence interval 83.4-164.9 microM). The key metabolism of paraspinal muscle can be monitored by MD during the conventional posterior lumbar fusion surgery. The glycerol concentration in the paraspinal muscle is markedly increased compared with the deltoid muscle during the surgery. It is proposed that GCD can be used to evaluate surgery related paraspinal muscle damage. Changing body position did not affect the paraspinal muscle metabolism in the healthy subjects.

Udgivelsesdato: 2009-Jun OBJECTIVES: The objective of this study was to investigate the interchangeability of the EuroQol 5D (EQ-5D) and the Short Form 6D (SF-6D) in individuals with long-lasting low back pain to guide the optimal choice of instrument and to inform decision-makers about any between-measure discrepancy, which require careful interpretation of the results of cost-utility evaluations. METHODS: A cross-sectional study was conducted across 275 individuals who had spinal surgery on indication of chronic low back pain. EQ-5D and SF-6D were mailed to respondents for self-completion. Statistical analysis of between-measure agreement (using English weights) was based on Bland and Altman's limits of agreement and a series of linear regressions. RESULTS: A moderate mean difference of 0.085 (SD 0.241) was found, but because it masked more severe bidirectional variation, the expected variation between observations of EQ-5D and SF-6D in future studies was estimated at 0.546. The EQ-5D's N3 term alone explained a factor of 0.79 of the variation in between-measure differences, while the explanatory value of adding variables of age, sex, diagnosis, previous surgery, and occupational status was basically zero. A final model including only dummy variables for the N3 term and five identified framing effects explained a factor of 0.86 of the variation in between-measure differences. CONCLUSIONS: Although the EQ-5D and the SF-6D are both psychometrically valid for generic outcome assessment in long-lasting low back pain, it appears that they cannot generally be used interchangeably for measurement of preference values. Sensitivity analysis examining the impact of between-measure discrepancy thus remains a necessary condition for the interpretation of the results of cost-utility evaluations.

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. Udgivelsesdato: Feb

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.

Udgivelsesdato: 2007-May Although cost-effectiveness is becoming the foremost evaluative criterion within health service management of spine surgery, scientific knowledge about cost-patterns and cost-effectiveness is limited. The aims of this study were (1) to establish an activity-based method for costing at the patient-level, (2) to investigate the correlation between costs and effects, (3) to investigate the influence of selected patient characteristics on cost-effectiveness and, (4) to investigate the incremental cost-effectiveness ratio of (a) posterior instrumentation and (b) intervertebral anterior support in lumbar spinal fusion. We hypothesized a positive correlation between costs and effects, that determinants of effects would also determine cost-effectiveness, and that posterolateral instrumentation and anterior intervertebral support are cost-effective adjuncts in posterolateral lumbar fusion. A cohort of 136 consecutive patients with chronic low back pain, who were surgically treated from January 2001 through January 2003, was followed until 2 years postoperatively. Operations took place at University Hospital of Aarhus and all patients had either (1) non-instrumented posterolateral lumbar spinal fusion, (2) instrumented posterolateral lumbar spinal fusion, or (3) instrumented posterolateral lumbar spinal fusion + anterior intervertebral support. Analysis of costs was performed at the patient-level, from an administrator's perspective, by means of Activity-Based-Costing. Clinical effects were measured by means of the Dallas Pain Questionnaire and the Low Back Pain Rating Scale at baseline and 2 years postoperatively. Regression models were used to reveal determinants for costs and effects. Costs and effects were analyzed as a net-benefit measure to reveal determinants for cost-effectiveness, and finally, adjusted analysis (for non-random allocation of patients) was performed in order to reveal the incremental cost-effectiveness ratios of (a) posterior instrumentation and (b) anterior support. The costs of non-instrumented posterolateral spinal fusion were estimated at DKK 88,285(95% CI 81,369;95,546), instrumented posterolateral spinal fusion at DKK 94,396(95% CI 89,865;99,574) and instrumented posterolateral lumbar spinal fusion + anterior intervertebral support at DKK 120,759(95% CI 111,981;133,738). The net-benefit of the regimens was significantly affected by smoking and functional disability in psychosocial life areas. Multi-level fusion and surgical technique significantly affected the net-benefit as well. Surprisingly, no correlation was found between treatment costs and treatment effects. Incremental analysis suggested that the probability of posterior instrumentation being cost-effective was limited, whereas the probability of anterior intervertebral support being cost-effective escalates as willingness-to-pay per effect unit increases. This study reveals useful and hitherto unknown information both about cost-patterns at the patient-level and determinants of cost-effectiveness. The overall conclusion of the present investigation is a recommendation to focus further on determinants of cost-effectiveness. For example, patient characteristics that are modifiable at a relatively low expense may have greater influence on cost-effectiveness than the surgical technique itself--at least from an administrator's perspective.

Udgivelsesdato: 2006-Dec-1 STUDY DESIGN: Prospective randomized clinical study with a 5- to 9-year follow-up period. OBJECTIVE: The aim of the present study was to analyze the long-term outcome with respect to functional disability, pain, and general health of patients treated by means of circumferential lumbar fusion in comparison with those treated by means of instrumented posterolateral lumbar fusion. SUMMARY OF BACKGROUND DATA: Circumferential fusion has become a common procedure in lumbar spinal fusion both as a primary and salvage procedure. However, the claimed advantages of circumferential fusion over conventional posterolateral fusion lack scientific documentation. (The primary report with a 2-year follow-up has been published in Spine in 2002.) METHODS: From April 1996 to November 1999, a total of 148 patients (mean age, 45 years) with severe chronic low back pain were randomly selected for either posterolateral lumbar fusion (titanium Cotrel-Dubousset) or circumferential lumbar fusion (instrumented posterolateral fusion with anterior intervertebral support by a Brantigan cage). The primary outcome measure was the Dallas Pain Questionnaire (DPQ). The secondary outcome measures were the Oswestry Disability Index, the SF-36 instrument, and the Low Back Pain Rating Scale. All measures assessed the endpoint outcomes at 5 to 9 years after surgery. RESULTS: The available response rate was 93%. The circumferential group showed a significantly better improvement (P < 0.05) in comparison with the posterolateral group with respect to all four DPQ categories: daily activities, work/leisure, anxiety/depression, and social interest. The Oswestry Disability Index supported these results (P < 0.01). General health, as assessed by means of the SF-36, also showed significantly better physical health (P < 0.01) in the circumferential group, whereas no significant difference was found with respect to mental health compared with the posterolateral group. The circumferential group experienced significantly less back pain (P < 0.05) in comparison with the posterolateral group. In regard to leg pain, no significant difference was found. CONCLUSION: Circumferential lumbar fusion demands more extensive operative resources compared with posterolateral lumbar fusion. However, 5 to 9 years after surgery, the circumferentially fused patients had a significantly improved outcome compared with those treated by means of posterolateral fusion. These new results not only emphasize the superiority of circumferential fusion in the complex pathology of the lumbar spine but are also strongly supported in all of the validated questionnaires used in the study.

Udgivelsesdato: 2006-Aug 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.

STUDY DESIGN: An experimental animal study with randomized, paired control design was conducted using a porcine model.OBJECTIVES: The aim of this study was to evaluate the influence of alendronate treatment and the significance of different amounts of bone graft on posterior lateral spine fusion.SUMMARY OF BACKGROUND DATA: Treatment with bisphosphonates inhibits osteoclast-induced bone resorption and increases bone quality and density. It has been widely used clinically for treatment of osteoporosis. Bisphosphonates have been reported to elongate the callus remodeling process during fracture healing. Bisphosphonate treatment may modify bone graft healing and the remodeling process in spine fusion. The bone resorption phase exists during the healing process. Extensive bone graft resorption could reduce the basis for new bone formation, which could be an important factor for failure of spine fusion. Furthermore, different amounts of initially applied bone graft may influence spine fusion rate and bone graft incorporation process.METHODS: Twenty-two pigs were included in the study. Eleven pigs in the treatment group received alendronate 10 mg/day p.o. for 3 months after surgery. The other 11 pigs received no bisphosphonate and served as control group. Posterior lateral fusion with the CD Horizon system was performed on the lumbar spine using different amounts of autograft (4 g on one side and 8 g on the other side) in all animals. The fusion was evaluated using radiograph, CT scan, and histomorphometry at 3 months after operation.RESULTS: There was no statistical difference in either fusion rate or fusion mass volume between the two groups. The fusion rate based on radiograph was 75% on the 8-g autograft side and 45% on the 4-g side (P < 0.05). The mean volume of fusion mass was 2.36 cm3 on the 4-g side and 3.29 cm3 on the 8-g side (P < 0.01). No difference was found in either trabecular bone volume or fusion rate between treatment and control groups using histologic evaluation.The treatment group showed a higher fibrous tissue volume(P < 0.05), higher proportion of woven bone structure(P < 0.001), and lower bone marrow volume (P = 0.088) in the fusion mass. Different amounts of bone graft did not change the tissue composition of the fusion mass.CONCLUSIONS: Alendronate treatment in this study decreased fusion mass remodeling without inhibiting fusion rate. Increased amounts of autologous bone graft could improve the fusion rate in this experimental spine fusion study.

Several studies have suggested that psychosocial distress is an important predictor of negative outcome in lumbar spine surgery. Ozguler et al. [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 (-39 years/40-59 years/60+ years), 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 1 year/1-2 years/more than 2 years), 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 (low = group1 + 2/high = group 3 + 4). 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

This study investigated the healing potential of allograft from bisphosphonate-treated animals in anterior lumbar spine interbody fusion. Three levels of anterior lumbar interbody fusion with Brantigan cages were performed in two groups of five landrace pigs. Empty Brantigan cages or cages filled with either autograft or allograft were located randomly at different levels. The allograft materials for the treatment group were taken from the pigs that had been fed with alendronate, 10 mg daily for 3 months. The histological fusion rate was 2/5 in alendronate-treated allograft and 3/5 in non-treated allograft. The mean bone volume was 39% and 37.2% in alendronate-treated or non-treated allograft (NS), respectively. No statistical difference was found between the same grafted cage comparing two groups. The histological fusion rate was 7/10 in all autograft cage levels and 5/10 in combined allograft cage levels. No fusion was found at all in empty cage levels. With the numbers available, no statistically significant difference was found in histological fusion between autograft and allograft applications. There was a significant difference of mean bone volume between autograft (49.2%) and empty cage (27.5%) (P

BACKGROUND CONTEXT: The biological factors determining a successful spinal fusion have not yet been fully determined. PURPOSE: To determine the influence of graft cell vigor on fusion rate and fusion mass using in vitro osteoblast proliferation as a predictor. STUDY DESIGN: Animal study randomizing to posterolateral fusion with autograft with or without pedicle-screw instrumentation. PATIENT SAMPLE: Twenty adult Gottingen mini-pigs. OUTCOME MEASURES: Fusion rate measured both with X-ray and computed tomography (CT) as well as amount of fusion mass determined with three-dimensional CT. METHODS: Animals underwent posterolateral fusion with autograft either with or without pedicle-screw instrumentation. Additional graft was harvested for osteoblastlike cell culture. Cells were counted after 3 weeks, and their proliferative capacity was correlated to fusion rate and fusion amount. RESULTS: Cell count was significantly higher in the fused animals (p CONCLUSIONS: The achievement of a solid spinal fusion using autograft is related to properties of the bone-forming cells in the graft and fusion bed. Most likely it is the number of cells and not their proliferative capacity that is the most important factor.