Background

Previous surgery is known to increase the risk of complications during spine surgery, but few studies have quantified the dose-response effect using multivariate models to account for confounders. We quantified the effect of the number of prior spine surgeries on perioperative complications in patients undergoing surgery for lumbar degenerative disorders.

Posterior lumbar fusion is a frequently performed procedure in spinal surgery. High percentages of good and excellent results are indicated by physicians. On the other hand patient-based outcomes are reported. Little is known about the correlations of these two assessment types. We aimed at their comparison.

The analysis included 1013 patients with degenerative spinal disease or spondylolisthesis from an international spine registry, treated with posterior lumbar fusion. All patients were pre/postop assessed by physician-based McNab criteria (‘excellent’, ‘good’, ‘fair’, ‘poor’). Of these patients, 210 (mean age 61 years; 57% females) were in addition assessed by patient-based Oswestry Disability Index (ODI). The remaining 803 patients (mean age 59 years; 56% females) were assessed by patient-based Core Outcome Measure Index (COMI), including

Visual Analogue Scale (VAS) for back and leg pain as well as verbal self-rating (‘helped a lot’, ‘helped’, ‘helped only little’, ‘didn’t help’, ‘made things worse’). McNab criteria were compared to the Minimal Clinically Important Difference (MCID) in ODI (12.8), in VAS back (1.2) and leg pain (1.6). We investigated the correlations between McNab criteria and these patient-based outcomes.

In the ‘excellent’ group as rated by physicians, the proposed MCID was reached in 83% of patients for ODI, in 69% for VAS back and in 83% for VAS leg pain. All patients said the treatment had ‘helped’ or ‘helped a lot’. In the ‘good’ group 56% (ODI), 66% (back pain) and 86% (leg pain) reached the MCID. 96% of patients perceived the treatment as positive. In the ‘fair’ group 37% (ODI), 55% (back pain) and 63% (leg pain) reached the MCID. 49% had positive treatment considerations. The ‘poor’ group revealed 30% (ODI), 35% (back pain) and 44% (leg pain) of patients with reached MCID. Only 15% rated the treatment as positive.

The Spearman correlation coefficients between McNab criteria on the one hand and ODI, back and leg pain as well as patients’ verbal self-rating on the other hand were 0.57, 0.37, 0.36 and 0.46 respectively.

The comparison of physician and patient-based outcomes showed the highest correlations between McNab criteria and ODI, somewhat weaker correlations with patients’ self-rating and the weakest correlations with back and leg pain. Based on these findings, physicians’ evaluation of patient outcomes can be considered a valuable part of patient assessment, corresponding very well with patients’ perceptions of success or failure of spinal surgery.

Introduction: Quoted complication rates in older patients range from 2.5–80% after surgical treatment of LSS. There is general disagreement whether operative therapy is riskier for older versus younger spines. Using comprehensive literature review and data from the international “Spine Tango” register (www.eurospine.org), this study examines the risk of surgery for LSS relative to age.

Methods: Between May 2005 and August 2009 20’794 patients with various spinal pathologies were documented. The current study applied the following inclusion criteria:

- lumbar or lumbosacral degenerative spinal stenosis

This produced 1,493 patients, who were subdivided into three age groups:

< 65 yrs (n=609, 41%),

Results: Over 80% of patient outcomes were scaled as good or excellent by the treating physician with no significant differences between the age groups.

The surgical complication rate in the complete sample was 5.7%. Multivariate logistic regression showed surgery time (p< 0.001), fusion/rigid stabilization (p=0.025) and age group (p=0.043) as a significant co-variates for surgical complications. Group 3 had a 2.1-times higher likelihood for a surgical complication as in group 1.

The general complication rate of the complete sample was 2.9%. We found ASA (p=0.002), fusion / rigid stabilization (p=0.022) and age group (p=0.008) as significant influencing factors for general complications.

The follow-up complication rate was 10.2% and did not vary significantly between age groups, but multivariate logistic regression showed fusion/rigid stabilization (p< 0.001) and previous surgery (p=0.005) to be significant co-variates for FU complications.

Clearly age-related was the duration of hospital admission and level of ASA (both p< 0.001).

Discussion: The outcomes found in the “Spine Tango” register indicate that both surgical and general (particularly cardiovascular and urinary tract infections) complication rates after decompression for LSS are negatively influenced by age. The complication rates at FU showed no age-related variation, and according literature re-operation rates after surgery of the lumbar spine appear to actually decrease with aging.

Our study and literature leaves no doubt about that aged and very aged patients benefit from surgical treatment. Therefore, although we should be aware of the increased risk for surgical and general complications in this population, high age (> 75 yrs) should not be a main influencing factor in the choice of operative indication and strategy when treating LSS.

Background: Due to reported high rates of complications in Total Disc Replacement Swiss health care system demanded an obligatory national Health Technology Assessment-registry for Total Disc Replacement. Thus, SWISSspine was founded in 2003 to assess efficiency, cost effectiveness, safety and find predictors of co-morbidity for surgical outcome.

Study design and Methods: In an observational multi center mode data were collected from March 2005 to August 2008 with detailed frequency statistics. Preoperative assessment, 3 month and 1 year FU using EQ-5D, NASS-Instrument and co-morbidity-forms for patients were applied. The surgeons administered OR- and FU-forms. Statistics: multivariate regression analysis.

Patient sample: 427 interventions with 497 implants.

Results: A significant reduction of back pain: 71 to 31 (p< 0.001) and leg pain 54.7 to 20.7 (p< 0.001) was documented (VAS, 1year postop). Quality of life measured in EQ-5D increased from 0.32 to 0.73. Opiate-usage decreased from 31.7% to 7.7%. Increasing ROM and re-established lordosis were seen. Overall 19 complications occurred, 12 revisions were performed. It was revealed that medicamentous treated depression had a negative influence on the outcome.

Conclusions: SWISSspine as a mandatory instrument was successfully implemented in the treatment-program of degenerative lumbar disc-diseases. The results provide evidence for patients benefit. Back- as well as leg pain was reduced. Complication- and revision rates were low. Medicamentous treated depression seems to have a negative influence on postoperative pain outcome in TDR. Our results obtained from SWISSspine provide a reasonable potential supporting surgeon in decision making for TDR especially in patients with medicamen-tous treated depression.

Introduction: Dural tears are one of the most frequent type of complication in posterior spinal fusion with little known about their predictors.

Method: Prospective consecutive study with an evidence level 2++ of 42 patients in the international spine registry Spine Tango, who had been treated between 05/2005 and 8/2008 with posterior spinal fusion after opening of the spinal canal. Median age was 62.7 yrs (min 12.5, max 90.5 yrs) with a female to male ratio of 2:1. In 42 of 1575 cases a dural tear occurred being the most frequent type of complication in our study sample. Multiple linear regression was performed on potential predictor-variables of the occurrence of dural tears.

Results: Hospital (p=0.02) and number of segments of fusion (p=0.018) were found to be predictors of the occurrence of dural tears in posterior spinal fusion. Number of fusions per hospital (min 25, max 526) and academic status of hospital had no influence on the rate of dural tears. Fusions of four and more segments showed an increase of the rate of dural tears by three compared to fusions of less than four segments.

Conclusion: Predictors of dural tears in posterior spinal fusion are hospital, independent of number of spinal surgeries and academic status of hospital, and number of segments of fusion. In fusions of four and more segments a threefold higher risk of dural tears in comparison to fusions of less than four segments should be taken into consideration.

Introduction: Posterior lumbar fusion, in many variations, is one of the frequently performed procedures in spinal surgery. High percentages of good and excellent results are indicated by physicians. On the other hand isolated patient-based outcomes are reported. However, little is known about correlation of these two assessment types. We aimed at their comparison.

Methods: The analysis included 567 patients from the international registry ‘Spine Tango’. 453 patients with degenerative disease and posterior lumbar fusion had preop and postop VAS separately indicating back- and leg-pain, surgery and follow up data. Mean age was 57y; female/male ratio was 52% to 48%. Remaining 114 patients with the same diagnoses and treatment had additional preop and postop Oswestry disability indices (ODI). Mean age was 61y; female/male ratio was 55% to 45%.

Physician administered McNab criteria “excellent, good, fair and poor” were compared to ODI, VAS back- and leg pain and to the patients answer describing the outcome of the operation with the following options: helped a lot, helped, helped only little, didn’t help and made things worse. Then the concept of minimum clinically important difference (MCID) was applied

Results: In the “excellent” group ODI-improvement was detected for all patients, the proposed MCID was reached in 90% for ODI. According to this model 85.2% of patients reached MCID for VAS leg pain and 54.1% for VAS back pain. All patient said that the treatment helped or helped a lot

In the “good” group 86% (MCID: 51.7%) of patients improved regarding ODI, 81% (MCID: 65,7%) regarding back and 93% (MCID: 89.4%) regarding leg pain. 99% of patients said that the treatment helped a lot, helped or helped only little.

65% (MCID: 40%) of patients in the “fair” group had improved ODIs. Even in this group 88% of patients perceived the treatment as helping a lot, helping or helping only little.

Moreover in the “poor” group had 60% (MCID: 40%) of patients improved ODIs, 55% (MCID: 40%) alleviated back and 36% (MCID: 30%) reduced leg pain. But only 30% of patient stated that the treatment helped or helped only little.

Spearman correlation coefficients for ODI, VAS back, VAS leg and patient’s verbal statement on overall outcome were 0.42, 0.18, 0.27 and 0.53.

Discussion: ‘Spine Tango’ registry, to date containing more than 13.000 documented surgeries and three times more outcome datasets, provides excellent opportunities for comparison of outcomes. The analysis of patient and physician-based outcomes showed good correlation with the highest correlation coefficient for patient’s verbal statement. With this study we can state that there is strong evidence that physicians evaluation of outcome is very good corresponding with the patients’ perception of success or failure of the analyzed procedure.

Purpose: SWISSspine is a national health technology assessment (HTA) registry for ballon kyphoplasty (BKP) and total disc arthroplasty (TDA). It was initiated to evaluate the safety, efficiency and cost-effectiveness of these products. It is the first mandatory orthopaedic HTA registry of its kind in Switzerland. The aim is to generate evidence for a decision about reimbursement by the Swiss basic health insurance.

Methods: During the time between March 2005 until June 2008, 331 interventions with 391 treated levels in 320 patients have been documented. Data was collected in a prospective, observational multicenter mode. The preliminary timeframe for the registry is three years. Data collection is performed preoperative, at 6 weeks, 3 months, 6 months and 1 year followup as well as annually thereafter. Surgery and followup case report forms are administered by spinal surgeons. Comorbidity questionnaires, NASS and EQ-5D forms are completed by patients.

Results: Significant and clinically relevant reduction of back pain, improvement of quality of life and reduction of pain killer consumption was seen in the 1 year followup. Improvement of preoperative segmental kyhposis was achieved in the majority of cases. There were three symptomatic cement extrusions with radiculopathy documented.

Conclusion: BKP is a safe and effective treatment concerning pain reduction, quality of life improvement and pain killer consumption. The SWISSspine registry proved to be an excellent tool for evaluation of this new technology and its results lead to a permanent coverage of BKP by the basic health insurance.

Introduction: To date, herniated nucleus pulposus (NP) with radiculopathy and central or lateral recess stenosis are considered as contraindications for lumbar disc arthroplasty. In the present study we used data from a unique mandatory spine register, SWISSspine to investigate associations between preoperative status of NP herniated/non herniated with presence/absence of sciatica and clinical outcome

Methods: Between 3/2005 and 8/2008, 358 mono-segmental lumbar total disc arthroplasties were documented in a prospective observational multicenter mode. The data collection included peri-operative data and clinical outcomes based on NASS, EuroQol and VAS. The patients were divided into 4 groups: group I-128 patients with herniated NP with sciatica, group II-48 patients with herniated NP without sciatica, group III-74 patients without herniated NP but with sciatica and group IV-108 patients without herniated NP and no sciatica (classic indication). The groups were pair wise compared regarding 1-year postoperative VAS, EuroQol and NASS scores using ANOVA-test with Boferroni-Holm adjustment (α=0.05)

Results: The 4 groups had similar demographic characteristics. Statistical analyses showed no significant outcome differences between the classic and the other indications. For example a outcomes for group IV: NASS back pain pre-post: 72.0/31.7 EQ-5D pre-post: 0.32/0.69.

Discussion and Conclusion: Our analysis revealed no differences between patients with herniated NP combined with neural compression and patients with stenosis of recesses regarding pain alleviation and QoL improvement. The findings suggest that these diagnoses may not have to be considered as absolute contraindications for TDR anymore. The results of this multicenter observational study however, need to be verified in a controlled or experimental study design.

Background: context: Length of hospital stay (LOS) varies widely within patients with posterior spinal fusion. So far there is little evidence on its co-variates.

Purpose: This study examined which co-variates influence LOS in posterior spinal fusion. Study design: Prospective consecutive documentation of hospital based interventions in the international spine registry Spine Tango. Patient sample: Between 05/2005 and 11/2006 data of 3437 patients were documented in the registry. 790 patients with degenerative spinal disease (614) or spondylolisthesis (176), who had been treated with posterior decompression and spinal fusion, were included in this study. Median age was 62.8 yrs (min 13.2 yrs, max 89.8 yrs) with a female to male ratio of 2:1. Median LOS was 11 days (IQR 8–14 d). Outcome measures: LOS was chosen as dependent outcome variable.

Methods: Multiple linear regression was performed on following independent variables: age, gender, main pathology, number of spinal segments of posterior fusion, level of fusion, number of previous spinal surgeries, operation time, clinic (number of fusions, academic status), surgeon credentials, type of fusion (sole fusion, fusion + instrumentation, fusion + instrumentation + cage).

Results: Clinic (p< 0.0001) was found to be a highly significant co-variate for LOS (min 7 d, max 14 d). Number of fusions per clinic (min 25, max 434) and academic status of clinic had no influence on LOS. Further significant covariates were surgeon credentials (surgeons in training: 8.5 d, specialised spine surgeons: 11 d, orthopaedic or neurosurgeons: 12 d; p=0.001), number of spinal segments of posterior fusion (1 segment: 10 d, 2–3 segments: 12 d, 4–5 segments: 12.5 d, > 5 segments: 15 d; p=0.002), and age group (< 50 yrs: 9 d, 50–59 yrs: 11 d, 60–69 yrs: 12 d, ≥70 yrs: 13 d; p=0.01). Borderline significance was found for gender (women: 12 d, men: 10 d; p=0.05). All other variables showed no influence on LOS.

Conclusion: Co-variates of LOS of patients with posterior spinal fusion are clinic, independent of number of spinal surgeries per clinic and academic status of clinic, surgeon credentials, number of segments of fusion, age group, and gender. A short LOS in surgeries performed by surgeons in training is explained by a smaller number of segments of fusions in these procedures. A subgroup analysis on the co-variate clinic should be performed assessing further explanatory variables. However, this goes beyond the possibilities of documentation in a spine registry.

Posterior lumbar fusion is one of the most frequent procedures in spinal surgery. This study examined which factors predict physician-based outcomes in posterior lumbar fusion within the international spine registry Spine Tango.

This study used prospective consecutive hospital based documentation. Between May 2005 and October 2007 720 patients had been treated with posterior lumbar fusion for degenerative disease or spondylolisthesis. McNab criteria as commonly used physician-based outcomes were chosen as dependent outcome variable. We dichotomised the original McNab criteria combining “excellent” with “good” to “good”, and “fair” with “poor” to “poor”. Multivariate logistic regression was performed on following potential predictor-variables: age, gender, main pathology, number of previous spinal surgeries, number of spinal segments of posterior fusion, operation time, surgeon credentials, follow-up interval.

Median age was 63 years (range 13–90 yrs) with a female to male ratio of 6.3:3.7. Number of previous spinal surgeries (p< 0.001) and follow-up interval (p< 0.001) were found to be predictors of the dichotomised McNab criteria. Patients without previous spinal surgery showed the highest ratio of “good” to “poor” outcome (80.5%:19.5%). This ratio was almost consistently decreasing with the number of previous spinal surgeries to 40%:60% in patients with more than five previous surgeries. At six and twelve-weeks follow-up outcomes were significantly better than after one year, without significant differences between other follow-up intervals. Other examined co-variables showed no influence on the outcomes.

Predictors of physician-based outcomes in posterior lumbar fusion are “number of previous spinal surgeries” and “follow-up interval”. In patients with more than five previous spinal surgeries a higher likelihood of “poor” outcomes should be taken into consideration. A too positive outcome may occur at six or twelve-week’s follow-up.

Introduction: As an example of possibilities of Spine Tango we extracted data on dural tears, one of the most frequent types of complications in posterior spinal fusion. Little is known about their predictors. This study examined which factors predict the occurrence of dural tears in posterior spinal fusion.

Methods: Prospective consecutive documentation of hospital based interventions with an evidence level 2++. Between 05/2005 and 11/2006 data of 3437 patients were documented in the registry. 929 patients, who had been treated with posterior spinal fusion after opening of the spinal canal, were included in this study. Median age was 62.7 yrs (min 12.5, max 90.5 yrs) with a female to male ratio of 2:1. In 18 of 929 cases a dural tear occurred. Dural tears being the most frequent type of complications in the registry were chosen as dependent outcome variable (3–6). Multiple linear regression with stepwise elimination was performed on potential predictor-variables of the occurrence of dural tears. Benchmarking compared the performance of single hospitals with international peers.

Results: Hospital (p=0.02) and number of segments of fusion (p=0.018) were found to be predictors of the occurrence of dural tears in posterior spinal fusion. Number of fusions per hospital (min 25, max 526) and academic status of hospital had no influence on the rate of dural tears. Fusions of four and more segments showed an increase of the rate of dural tears by a factor of three compared to fusions of less than four segments. There was no significant difference between fusions of one segment and fusions of two or three segments (1.3 vs. 1.9%) as well as between fusions of four or five segments and fusions of more than five segments (4.6 vs. 4.2%). Differences between hospitals remained when benchmarking dural lesions with case mix.

Discussion: The feasibility of data analysis and benchmarking from the International Spine Registry Spine Tango could be demonstrated. Predictors of dural tears in posterior spinal fusion are

hospital and

In fusions of four and more segments a threefold higher risk of dural tears in comparison to fusions of less than four segments should be taken into consideration. A subgroup analysis on the predictor-variable hospital should be performed assessing further covariates. However, this goes beyond the possibilities of documentation in this international spine registry.

Introduction: Lumbar spinal stenosis is a frequent indication for spinal surgery. The predictive quality of treadmill testing and MRI for diagnostic verification is not yet clearly defined. The aim of our study was to assess correlations between treadmill testing and MRI findings in the lumbar spine.

Methods: Patients with lumbar spinal stenosis who had been admitted for surgical treatment by means of decompression with or without stabilisation were prospectively examined. We included patients with lumbar spinal stenosis as defined by clinical symptoms like low back and/or leg pain, which increased when walking, and by the area of the dural sac examined by MRI. We excluded patients with clinically manifest peripheral arterial disease, polyneuropathy or musculoskeletal impairments compromising the ability to walk. Treadmill tests were performed using the standardized testing protocoll by Deen at a speed of 0.5 m/sec without inclination. After the onset of symptoms (pain, weakness or dysaesthesia), each patient decided when to end the test.

The area of the dural sac and neuroforamina was examined with MRI for the narrowest spinal segment. ODI and VAS were used for clinical assessment.

Results: 25 patients were included with a median age of 67 years (Interquartile range IQR 60–72 yrs). In the narrowest spinal segment the median area of the dural sac was 91mm2 (IQR 67–135 mm2). The median ODI was 66 percent (IQR 64–72 percent). The median walking distance in the treadmill test was 70 m (IQR 30–130 m). The distance reached in the treadmill test correlated with the area of the dural sac (Spearman’s rho=0.53) and ODI (rho=0.51), but not with the area of the neuroforamina and VAS.

Discussion: The treadmill test helps objectifying pre- and postsurgical clinical complaints and verifying a lumbar spinal stenosis by creating a situation of dynamic strain. Moreover, the treadmill test lets the patient experience his own physical limits and enables the examiner to attain a replicable postoperative assessment. The distance reached in the treadmill test predicts the grade of stenosis in MRI but has a limited diagnostic importance for the level of clinical symptoms in lumbar spinal stenosis.