Most people experience low back pain (LBP) at least once in their lifetime. A minority goes on to develop persistent LBP causing significant socioeconomic costs. Aim of this study was to identify factors that influence the progression of acute to persistent LBP at an early stage (Hilfiker et al. 2007).

Prospective inception cohort study of patients attending a health practitioner for their first episode of acute LBP or recurrent LBP after a pain free period of at least six months. Patients were assessed at baseline addressing occupational and psychological factors as well as pain, disability, quality of life and physical activity, and followed up over six months. Baseline and follow-up questionnaires were based on the recommendations of the Multinational Musculoskeletal Inception Cohort Study (MMICS) Statement (Pincus et al. 2008). Variables were combined to the three indices ‘working condition’, ‘depression and maladaptive cognitions’ and ‘pain and quality of life’.

The index ‘depression and maladaptive cognitions’ comprising of depression, somatisation, a resigned attitude towards the job, fear-avoidance, catastrophizing and negative expectations on return to work was found to be a significant baseline predictor for persistent LBP up to six months (OR 5.1; 95%CI 1.04–25.1). The diagnostic accuracy of the predictor model had a sensitivity of 0.54 and a specificity of 0.90. Positive likelihood ratio was moderate with 5.3, negative likelihood ratio 0.5. Overall predictive accuracy of the model was 81%. The area under the curve in receiver operating characteristic (ROC) analysis of the index was 0.78 (CI95% 0.65–0.92), demonstrating a satisfactory quality of discrimination.

Psychological factors in patients with acute LBP in a primary care setting correlated with a progression to persistent LBP up to six months. The benefit of including factors such as ‘depression and maladaptive cognition’ in screening tools is that these factors can be addressed in primary and secondary prevention.

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.

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: 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.

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: The number of total ankle replacements has been raising in the last years. Most publications present short- and medium-term results. Comparison of outcomes is difficult because of inconsistent terminology and different parameters used. Moreover, poorly performing implants cannot be identified quickly because of low numbers, delayed reporting or publication bias.

Methods: Therefore, we have developed a module for total ankle prostheses in the framework of the International Documentation and Evaluation System (IDES) for standardized and centralized documentation of TAA outcomes. Content validation was conducted with a single surgeon series of 74 HINTEGRA_ ankle replacements.

Results: Between March 2004 and February 2008 74 patients were treated. The preoperative diagnosis was 18.9% osteoarthritis, 32.4% rheumatoid arthritis, 43.3% posttraumatic, 1.4% osteonecrosis and 4% others. There were intraoperative complications in 4%, local postoperative complications in 17.6% and revision surgeries in 16.2% of patients. The AOFAS hind-foot score improved from 23.8 points preoperative to 75.3 points after a mean followup time of 8.4 months. No significant differences in outcome were revealed between the various diagnostic groups.

Conclusion: The IDES-forms facilitate a structured and standardized data collection that is feasible in a research orientated but also purely clinical setting; this because of the different extents to which data can be recorded. The consistent use of the system assures a stringent internal quality assurance, and more interesting, an external quality assurance by means of comparisons and benchmarking with other users feeding the data pool with the exact same variables and outcomes. The Hintegra ankle appeared as a safe device with low complication rates in the hands of a foot and ankle specialist. A surgical learning curve was seen in the first two years.

Introduction: Studies about the influence of patient characteristics on mechanical socket failure in THA apply different methodologies and reveal inconclusive results. In addition the fixation mode has rarely been in the focus of investigation.

Methods: We conducted a two-arm matched pairs case-control study assessing the influence of patient characteristics sex, age, weight, BMI, diagnosis, and activity level (Charnley classification) on the odds for mechanical socket loosening. The cemented and uncemented fixation mode was analyzed separately.

Results: 299 cases and 986 controls were included in the cemented study arm and 510 cases and 3000 controls in the uncemented arm. Women had reduced loosening odds for the cemented (OR=0.59, p=0.0024) and uncemented (OR=0.63, p=0.0001) fixation compared to men (OR=1). Each additional year the intervention was postponed reduced the loosening odds by about 2 % for cemented (OR=0.98, p=0.017) and uncemented (OR=0.98, p=0.0002) sockets. In cemented sockets the weight group of 73–82 kg had lower loosening odds (OR=0.63, p=0.017) than the lighter (OR> 0.92) and heavier (OR> 1.1) weight groups. There were no significant effects of weight in the uncemented group. In contrast, obese patients (BMI> 30) with uncemented sockets displayed elevated loosening odds (OR=1.41, p=0.034) compared to an insignificant effect in the cemented arm. Osteonecrosis was the only main pathology revealing elevated loosening odds (OR=1.27, p=0.049) but only in cemented sockets. The Charnley classification as an indirect proxy of activity revealed changing and insignificant effects.

Conclusions: Female sex and a delayed intervention have similarly protective effects on the odds for cemented and uncemented socket loosening. Whilst a certain body weight range has a significantly protective effect in cemented sockets the more important finding is the significantly increased risk for uncemented socket loosening in obese patients. Patients with osteonecrosis are the only etiologic group at a significantly increase risk for socket loosening, but only with a cemented fixation. The Charnley classification as a surrogate for activity level had no influence on loosening risks in either socket fixation mode. Level of Evidence: Level III (case-control study)

Introduction: Randomized Controlled Trials (RCT) are the golden standard in nowadays evidence based outcome assessment. Nevertheless, RCTs in surgery are associated with several concerns. The major concern focuses on ethical issues when randomization is done.

Method: We conducted an indebt analysis on advantages and disadvantages of three types of data acquisition (Case Control Study (CCS), RCT, and Registries) where scientific impact, ability to assess changes over time, cost efficiency, time consumption, ability to provide bench marks and other variables are compared.

Results: RCTs are best regarding the scientific impact. Registers are superior in detecting changes over time (post market surveillance, early warning system), cost efficiency, time consumption, ability to provide benchmarks, local/national/international comparability and ability to let private practitioners participate. CCSs are of minor value in respect to all the assessed variables.

Conclusion: In Surgery, registries are an excellent alternative to RCTs if a great majority of the treating physicians (in respect to a therapy) participate and if all the treated patients (per physician) are included. The register increases its scientific impact if alternative therapies are included (control). In this case, the scientific impact of a register is getting nearly equivalent to RCTs.

Take home message: If ethical aspects allow an RCT, than the RCT is the study set up of choice when a new technique/implant has to be introduced in the market. Once the implant has proved its evidence, the following post market surveillance should be accompanied by registries (introduction of an implant in each country). If an RCT is not indicated (ethical or other contra indications), than registries should be used to prove evidence for an indicated therapy. CCSs are not recommended.

Aims: The study was carried out to describe the long-term development of relevant clinical parameters after total hip arthroplasty (THA). Methods: Primary and follow-up data from 26‘019 THA from 9‘801 men and 11‘144 women were monitored across a postoperative period of 15 years. The population was described as one group and according to Charnley. Results: Patients experienced significant pain relief and major improvements in mobility and hip motion. The 5% of patients with preoperatively no or mild hip pain grew to 90–95% postoperatively and was 85% 15 years later. The 8% patients with a preoperatively free walking time greater 30 min. increased to 60% postoperatively. 15 years after the THA 60% managed free walking times up to 30 minutes. A hip flexion greater 90 degrees was preoperatively possible for 22% of the patients, postoperatively for 78%. Up to 94% judged the outcome as excellent or good after one year and 84% after fifteen years. The prevalence of radiographically loose stems increased from 0.87% to 14.44% 14 years postoperatively. Simultaneously, the prevalence of radiographically loose cups increased from 0.8% to 16.67%. Conclusions: A THA delivers significant gain in mobility, hip motion and pain relief and a high number of satisfied patients. A constant deterioration of abilities and satisfaction could be observed beginning three to five years after the primary operation. However, 15 years postoperatively, these abilities were still superior to the preoperative levels. A steady increase in radiographically loose components was noted. It took patients three to five years to reach their maximum outcome.

Aims: New threshold levels for a classification of Harris hip score (HHS) with respect to patient satisfaction after total hip arthroplasty (THA) were calculated. Methods: Registry data from four follow-up intervals (< =3, 3–6, 6–9, > 9 years) from 3824 female and 4002 male patients were analyzed and optimal agreements between patient satisfaction and HHS classes were calculated using kappa values (κ). Patients were classified into Charnley classes A and B/C. HHS outcome was transformed into a binary format (positive, negative). Results: Associations between outcomes of the complete patient group using the normal HHS-classification (100, 90, 80,< 70) were weak (κ≤ 0.42). For a binary outcome classification with positive (excellent, good) and negative (fair, poor) results, associations improved especially for Charnley A patients (κ=0.46). Using the recalibrated HHS, the separation of patients in Charnley A vs. B/C and a binary outcome classification resulted in clear associations between HHS results and patient evaluation in both groups A (κ=0.527) and B/C (κ=0.424). The new thresholds were 95 (good), 75 (fair) and 65 (poor) for Charnley A and 95, 75 and 60 for Charnley B/C respectively. Conclusions: The newly calibrated HHS can differentiate between a patient perceived positive and a negative outcome in Charnley A and B/C patients. The differentiation between these two groups is essential since Charnley B and C patients have, by definition, an inferior mobility compared to Charnley A patients which can render a successful THA as fair and poor in many of those patients if the traditional HHS classification is applied.

We analysed follow-up data from 18 486 primary total hip arthroplasties performed between 1967 and 2001 to assess the validity of clinical procedures in diagnosing loosening of prosthetic components. Sensitivity, specificity and predictive values were estimated with the radiological definition of loose or not loose as the ‘gold standard’.

The prevalence of acetabular loosening increased from 0.6% to 13.9% during the period of the study and that of femoral loosening from 0.9% to 12.1%. Sensitivities and positive predictive values were low, suggesting that clinical procedures could not replace radiological assessment in the identification of loose prostheses. Specificities and negative predictive values were constantly above 0.86. The possibility of there being a prosthesis which is not loose in asymptomatic patients was consequently very high, particularly during the first five to six years after operation.

The necessity of periodic clinical and radiological follow-up examinations of asymptomatic patients during the first five to six years after operation remains questionable. Symptomatic patients, however, require radiological assessment.