Axial low back pain: one painful area--many perceptions and mechanisms.

Axial low back pain can be considered as a syndrome with both nociceptive and neuropathic pain components (mixed-pain). Especially neuropathic pain comprises a therapeutic challenge in practical experience and may explain why pharmacotherapy in back pain is often disappointing for both the patient and the therapist. This survey uses epidemiological and clinical data on the symptomatology of 1083 patients with axial low back pain from a cross sectional survey (painDETECT). Objectives were (1) to estimate whether neuropathic pain contributes to axial low back pain and if so to what extent. (2) To detect subgroups of patients with typical sensory symptom profiles and to analyse their demographic data and co-morbidities. (3) To compare patients with and without prior intervertebral disc surgery (IVD). Neuropathic pain components could be detected in 12% of the entire cohort. Cluster analyses of these patients revealed five distinct subgroups of patients showing a characteristic sensory profile, i.e. a typical constellation and combination of symptoms. All subgroups occurred in relevant numbers and some showed distinct neuropathic characteristics while others showed nociceptive features. Post-IVD-surgery patients showed a tendency to score more "neuropathic" than patients without surgery (not statistically significant). Axial low back pain has a high prevalence of co-morbidities with implication on therapeutic aspects. From these data it can be concluded that sensory profiles based on descriptor severity may serve as a better predictor for therapy assessment than pain intensity or sole diagnosis alone. Standardized phenotyping of pain symptoms with easy tools may help to develop an individualized therapy leading to a higher success rate in pharmacotherapy of axial low back pain.

Anteroposterior and rotational stability in fixed and mobile bearing unicondylar knee arthroplasty: a cadaveric study using the robotic force sensor system.

PURPOSE: Different bearing designs in unicondylar knee arthroplasty (UKA) have been developed in order to influence the rate of polyethylene wear. Increased anteroposterior translation and rotation after UKA has been hypothesized due to changes in joint surface geometry. The mobile bearing design was expected to show increased anteroposterior translation compared to the fixed bearing and biconcave bearing design. METHODS: Six human cadaver knees were used for the tests. Anteroposterior and rotational knee stability was analysed in 0°, 30°, 60°, 90° and 120° of knee flexion using a robotic testing system (KR 125, KUKA Robots Augsburg, Germany). Three forces and moments were measured in a Cartesian coordinate system with a resolution of 1.0 N and 0.1 Nm. RESULTS: There was no difference between the native knees and the knees after UKA in AP translation and rotation in all knee flexion angles. The factor knee flexion angle had a significant impact on the anterior translation when the type of bearing was neglected (p ≤ 0.015). CONCLUSION: This study shows that the natural knee stability in AP translation and rotation can be preserved in UKA. The preserved knee stability in different planes after UKA underlines the advantage of UKA when surgery is required in osteoarthritic changes of the medial compartment.

Accurate long-term prediction of height during the first four years of growth hormone treatment in prepubertal children with growth hormone deficiency or Turner Syndrome.

BACKGROUND/AIMS: The study aim was to develop and validate models for long-term prediction of growth in prepubertal children with idiopathic growth hormone deficiency (GHD) or Turner syndrome (TS) for optimal, cost-effective growth hormone (GH) therapy. METHODS: Height was predicted by sequential application of annual prediction algorithms for height velocity in cohorts of GHD (n = 664) and TS (n = 607) as documented within KIGS (Pfizer International Growth Database). As height prediction models also require an estimate of weight, new algorithms for weight increase during the first to fourth prepubertal years on GH were developed. RESULTS: When height was predicted from the start of GH treatment, the predicted and observed mean (SD) gain over 4 years was 30.4 (3.4) cm and 30.1 (4.9) cm, respectively, in GHD patients, and 27.2 (2.2) cm and 26.6 (3.5) cm, respectively, in TS patients. For all 4 years, gains of weight SD scores (SDS) were accurately described as a function of weight SDS and observed gain in height SDS (R(2) > 0.89). CONCLUSION: In GHD and TS patients treated with GH, an accurate prepubertal long-term prediction of height development in groups is possible. Based on this, an optimal individual height outcome could be simulated.

Expectation, satisfaction and clinical outcome of patients after total knee arthroplasty.

PURPOSE: There is a well-known difference between patients expectation, satisfaction and the measured clinical outcome in total knee arthroplasty (TKA). It has been hypothesized that higher expectation prior to surgery and higher satisfaction will show better clinical outcome according to well-established scoring systems, frequently used for assessment after TKA. METHODS: A consecutive group of 102 patients was included who received TKA for degenerative osteoarthritis. A modified patients expectation form was used prior and 8 months after surgery. Furthermore, the KSS, WOMAC and SF-36 served for patient assessment. Patients were grouped in responder and non-responder according to their level of expectation and fulfilment of expectation after surgery using a Likert scale. RESULTS: A total of 54 patients (53%) showed expectation prior to surgery of 1 or 2 and a satisfaction after surgery of 1 or 2 according to the Likert scales. These patients were classified as responders. Considering the continuous parameters of KSS, SF-36 and WOMAC, a few statistically significant differences were found between the responders and non-responders at baseline (pre-surgery) and at the fulfilment of their expectation after surgery. Patient expectation prior to surgery did not differ between both groups. The more satisfied patients showed significant better results in the KSS, WOMAC and SF-36 after surgery. The parameters general health (SF-36) and role emotional (SF-36) measured prior to surgery dominate the predictive potential to get a responder with sensitivity of 74%, specificity of 81% and a rate of correct classification of 78%. CONCLUSION: This study has shown that patient satisfaction correlates well with the clinical outcome according to the KSS, WOMAC and SF-36. The indication for TKA should consider the general health, emotional role and knee function of the patients as well in order to predict patient's outcome.

Fibromyalgia and neuropathic pain--differences and similarities. A comparison of 3057 patients with diabetic painful neuropathy and fibromyalgia.

BACKGROUND: Patients with diabetic neuropathy (DPN) and fibromyalgia differ substantially in pathogenetic factors and the spatial distribution of the perceived pain. We questioned whether, despite these obvious differences, similar abnormal sensory complaints and pain qualities exist in both entities. We hypothesized that similar sensory symptoms might be associated with similar mechanisms of pain generation. The aims were (1) to compare epidemiological features and co-morbidities and (2) to identify similarities and differences of sensory symptoms in both entities. METHODS: The present multi-center study compares epidemiological data and sensory symptoms of a large cohort of 1434 fibromyalgia patients and 1623 patients with painful diabetic neuropathy. Data acquisition included standard demographic questions and self-report questionnaires (MOS sleep scale, PHQ-9, PainDETECT). To identify subgroups of patients with characteristic combinations of symptoms (sensory profiles) a cluster analysis was performed using all patients in both cohorts. RESULTS: Significant differences in co-morbidities (depression, sleep disturbance) were found between both disorders. Patients of both aetiologies chose very similar descriptors to characterize their sensory perceptions. Burning pain, prickling and touch-evoked allodynia were present in the same frequency. Five subgroups with distinct symptom profiles could be detected. Two of the subgroups were characteristic for fibromyalgia whereas one profile occurred predominantly in DPN patients. Two profiles were found frequently in patients of both entities (20-35%). CONCLUSIONS: DPN and fibromyalgia patients experience very similar sensory phenomena. The combination of sensory symptoms--the sensory profile--is in most cases distinct and almost unique for each one of the two entities indicating aetiology-specific mechanisms of symptom generation. Beside the unique aetiology-specific sensory profiles an overlap of sensory profiles can be found in 20-35% of patients of both aetiologies.

Sensory symptom profiles and co-morbidities in painful radiculopathy.

Painful radiculopathies (RAD) and classical neuropathic pain syndromes (painful diabetic polyneuropathy, postherpetic neuralgia) show differences how the patients express their sensory perceptions. Furthermore, several clinical trials with neuropathic pain medications failed in painful radiculopathy. Epidemiological and clinical data of 2094 patients with painful radiculopathy were collected within a cross sectional survey (painDETECT) to describe demographic data and co-morbidities and to detect characteristic sensory abnormalities in patients with RAD and compare them with other neuropathic pain syndromes. Common co-morbidities in neuropathic pain (depression, sleep disturbance, anxiety) do not differ considerably between the three conditions. Compared to other neuropathic pain syndromes touch-evoked allodynia and thermal hyperalgesia are relatively uncommon in RAD. One distinct sensory symptom pattern (sensory profile), i.e., severe painful attacks and pressure induced pain in combination with mild spontaneous pain, mild mechanical allodynia and thermal hyperalgesia, was found to be characteristic for RAD. Despite similarities in sensory symptoms there are two important differences between RAD and other neuropathic pain disorders: (1) The paucity of mechanical allodynia and thermal hyperalgesia might be explained by the fact that the site of the nerve lesion in RAD is often located proximal to the dorsal root ganglion. (2) The distinct sensory profile found in RAD might be explained by compression-induced ectopic discharges from a dorsal root and not necessarily by nerve damage. These differences in pathogenesis might explain why medications effective in DPN and PHN failed to demonstrate efficacy in RAD.

A cross-sectional survey of 3035 patients with fibromyalgia: subgroups of patients with typical comorbidities and sensory symptom profiles.

OBJECTIVES: Patients with FM are heterogeneous. They present with a variety of pain qualities, sensory abnormalities and additional comorbidities. The aim was to identify clinically distinguishable subgroups of patients. METHODS: This investigation uses epidemiological and clinical data of 3035 FM patients from a cross-sectional survey (painDETECT) to (i) describe characteristic epidemiological data and comorbidities and (ii) detect subgroups of patients with typical patterns of sensory symptoms and comorbidities. RESULTS: Clinically relevant sensory abnormalities (strongly, very strongly present) included pressure pain (58%), prickling (33%), burning (30%) and thermal hypersensitivity (24%). Pain attacks were complained by 40% of patients. Moderate to severe comorbid depression occurred in 66% of patients. Only approximately 30% of the patients had optimal sleep. A hierarchical cluster analysis using descriptors of sensory abnormalities as well as the extent of comorbidities revealed five distinct subgroups of patients showing a characteristic clinical profile. Four subgroups of patients suffer from severe sensory disturbances in various combinations but lack pronounced comorbidities. In one subgroup, however, severe comorbidities dominate the clinical picture. Differences in pathophysiological mechanisms of pain generation can be attributed to each subgroup. CONCLUSIONS: The results of this study indicate that FM patients can be classified on the basis of their sensory symptoms and comorbidities by the use of a patient-reported questionnaire. Subgrouping of patients with FM may be used for future research and to tailor optimal treatment strategies for the appropriate patient.

A cross-sectional cohort survey in 2100 patients with painful diabetic neuropathy and postherpetic neuralgia: Differences in demographic data and sensory symptoms.

Patients with neuropathic pain syndromes are heterogeneous. They present with a variety of sensory symptoms and pain qualities. The knowledge of these data and etiology-specific differences is important to optimize clinical trial design and to develop more effective drugs. This investigation uses epidemiological and clinical data on the symptomatology of 2100 patients with painful diabetic neuropathy (DPN) and postherpetic neuralgia (PHN) from a cross-sectional survey (painDETECT) to (1) describe characteristic epidemiological differences, (2) analyse typical patterns of sensory symptoms in both cohorts and (3) determine whether questionnaires can capture these characteristics. PHN patients suffer more often from clinically relevant sensory disturbances although the average pain intensity is only marginally higher. This difference is particularly obvious with dynamic mechanical allodynia which is present in half of the PHN patients and in 18% of the DPN patients. Thermal hyperalgesia occurs twice as often in PHN. Numbness is described more often in DPN. Age has no influence on sensory symptoms in both entities. A hierarchical cluster analysis revealed five distinct subgroups of patients showing a characteristic sensory profile, a typical constellation and combination of neuropathic symptoms. All subgroups occur in relevant numbers in both entities but the frequencies differ between PHN and DPN. Since sensory symptoms likely translate into pain-generating mechanisms enrichment for potential treatment responders might be possible in clinical trials by assessing the sensory profiles. Patient-Reported Outcomes can be used to obtain a precise sensory characterization of each patient.

Achievement of guideline-defined treatment goals in primary care: the German Coronary Risk Management (CoRiMa) study.

AIMS: The success in achieving treatment goals for cardiovascular risk factors in primary care is largely unknown. Therefore, the goals of this study were (i) to assess whether routinely collected practice data can be used to evaluate treatment in primary care, (ii) to compare current treatment with goals of published guidelines, and (iii) to calculate future risk for cardiovascular events using these real-life data. METHODS AND RESULTS: In 110 physician offices in Germany, data from the patient management systems of all patients seen between January 1998 and June 2005 were extracted and analysed (715 644) with current guidelines used for reference. Of those patents, 284 096 (40% of all patients analysed) had one of the following diseases: 157 101 (55% of 284 096) had hypertension, 83 005 (29%) diabetes, 64 205 (23%) coronary artery disease (CAD), 174 787 (62%) hyperlipidaemia, and 136 360 (48%) had more than one of the listed diagnoses. During the last visit, treatment goals were achieved for total and LDL cholesterol in 9 and 29%, respectively, for blood pressure in 28%, and for HbA1c in 36%. Low achievement of treatment goals was also seen in patients with CAD or diabetes. Using the Framingham risk model and the SCORE Deutschland risk charts, 20 and 22% of patients had a high 10-year risk for a primary cardiovascular event and a fatal cardiovascular event, respectively. Achieving treatment goals for all risk factors would significantly reduce the number of high-risk patients. CONCLUSION: (i) Routinely collected practice data can be used to evaluate quality of care; (ii) 40% of patients in primary care have cardiovascular disease or diabetes; (iii) even in high-risk patients, the majority does not achieve treatment goals; and (iv) achieving the treatment goals would reduce the proportion of high-risk patients from 20 to <5%.