[Ultrasound examination of nerves of the upper extremities]. / Nervensonographie der oberen Extremitäten.

The ultrasound examination of peripheral nerves has been further developed in recent years and is recognized as an independent discipline by the German Society of Ultrasound in Medicine (DEGUM). A systematic ultrasound examination of the musculoskeletal system is not limited to the joints, muscles and bones but should also include the examination of nerves and blood vessels. Therefore, in the practice of ultrasound examination every rheumatologist should have at least a basic knowledge of the ultrasound examination of the peripheral nerves. In this article the authors present a landmark-based concept in which the three large nerves of the upper extremities can be completely visualized from proximal to distal and evaluated.

Energy Compression and Stabilization of Laser-Plasma Accelerators.

Laser-plasma accelerators outperform current radio frequency technology in acceleration strength by orders of magnitude. Yet, enabling them to deliver competitive beam quality for demanding applications, particularly in terms of energy spread and stability, remains a major challenge. In this Letter, we propose to combine bunch decompression and active plasma dechirping for drastically improving the energy profile and stability of beams from laser-plasma accelerators. Realistic start-to-end simulations demonstrate the potential of these postacceleration phase-space manipulations for simultaneously reducing an initial energy spread and energy jitter of ∼1-2% to ≲0.1%, closing the beam-quality gap to conventional acceleration schemes.

[Rehabilitation of orphan diseases in adulthood: osteogenesis imperfecta]. / Rehabilitation seltener Erkrankungen im Erwachsenenalter: Osteogenesis imperfecta.

Osteogenesis imperfecta (brittle bone disease) is an orphan disease caused by a genetic mutation in collagen metabolism. Bone fractures are the most common symptoms; however, the clinical manifestation can vary widely. Additional features can include blue sclera, dwarfism, bone deformities, muscular weakness, scoliosis, hearing loss and hypermobility of joints. Most patients show a reduction of skeletal function. This leads to an increased risk of being unable to continue their former work and to participate in social life. A comprehensive treatment includes drug therapy, surgery and rehabilitation. This article gives an overview of the current status of rehabilitation in adult patients with osteogenesis imperfecta.

A snapshot of European neurosurgery December 2019 vs. March 2020: just before and during the Covid-19 pandemic.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or Covid-19), which began as an epidemic in China and spread globally as a pandemic, has necessitated resource management to meet emergency needs of Covid-19 patients and other emergent cases. We have conducted a survey to analyze caseload and measures to adapt indications for a perception of crisis. METHODS: We constructed a questionnaire to survey a snapshot of neurosurgical activity, resources, and indications during 1 week with usual activity in December 2019 and 1 week during SARS-CoV-2 pandemic in March 2020. The questionnaire was sent to 34 neurosurgical departments in Europe; 25 departments returned responses within 5 days. RESULTS: We found unexpectedly large differences in resources and indications already before the pandemic. Differences were also large in how much practice and resources changed during the pandemic. Neurosurgical beds and neuro-intensive care beds were significantly decreased from December 2019 to March 2020. The utilization of resources decreased via less demand for care of brain injuries and subarachnoid hemorrhage, postponing surgery and changed surgical indications as a method of rationing resources. Twenty departments (80%) reduced activity extensively, and the same proportion stated that they were no longer able to provide care according to legitimate medical needs. CONCLUSION: Neurosurgical centers responded swiftly and effectively to a sudden decrease of neurosurgical capacity due to relocation of resources to pandemic care. The pandemic led to rationing of neurosurgical care in 80% of responding centers. We saw a relation between resources before the pandemic and ability to uphold neurosurgical services. The observation of extensive differences of available beds provided an opportunity to show how resources that had been restricted already under normal conditions translated to rationing of care that may not be acceptable to the public of seemingly affluent European countries.

[Sonography of the foot in rheumatology : Ultrasound diagnostics of the ankle joint and foot in the rheumatological routine]. / Fußsonographie in der Rheumatologie : Sonographische Diagnostik des Sprunggelenks und des Fußes im rheumatologischen Alltag.

Ultrasound examination of the joints is an essential component of diagnostics in rheumatology. Due to its easy accessibility, excellent image definition of soft tissue and bone surfaces with standardized scan sections and scoring systems, ultrasound examination of the joints enables decisions to be made on early and differential diagnostics, treatment monitoring and prognosis. Involvement of the ankle and foot is a common problem in both inflammatory and degenerative rheumatological diseases. Persisting inflammatory processes and bone destruction increase the burden of disease by causing a loss of mobility due to pain. As treatment is often prolonged it is an important issue for both the quality of life of affected patients and a burden on the resources of the healthcare system. The anatomical characteristics of the foot make it difficult to draw diagnostic conclusions by physical examination only. These diagnostic gaps in the remaining rheumatological questions can often be answered by ultrasound examination of the joint.

[Raynaud's phenomenon : Practical management]. / Raynaud-Phänomen : Praktisches Management.

Raynaud's phenomenon (RP) is a frequent and painful vasospasm of small arteries localized in acral body regions (most frequently the fingers). The more frequent so-called primary RP is caused merely by a functional dysregulation of the tonus of vascular walls. In contrast, the rarer secondary RP is additionally associated with structural abnormalities of blood vessels. Knowledge of RP is important for rheumatologists because secondary RP can be associated with the presence or development of severe underlying diseases, especially with systemic sclerosis. Thus, the rheumatologist has to be aware of this condition. In this article the diagnostic procedures and the most important treatment approaches are summarized.

Disturbance of verticality perception and postural dysfunction in Parkinson's disease.

OBJECTIVES: Verticality perception is known to be abnormal in Parkinson's disease (PD), but in which stage respective dysfunctions arise and how they relate to postural disorders remains to be settled. These issues were studied with respect to different dimensions of the subjective visual vertical (SVV) in relation to clinical parameters of postural control. MATERIALS & METHODS: All participants had to orientate a luminous line at random planar orientations to a strictly vertical position using an automated operator system. The SVV was analyzed in 58 PD patients and 28 control subjects with respect to (i) the angle between true and subjective vertical (deviation) and (ii) the variability of this across five measurements (variability). Results were referred to the subjective upright head position (SUH), the disease stage, and clinical gait/balance features assessed by the MDS-UPDRS and the Tinetti test. RESULTS: Parkinson's disease patients had significantly higher SVV deviation and variability than controls. With respect to disease stage, deviation developed before abnormal variability. SVV variability was associated with poor balance and gait performance, as well as postural instability. Deficits in SUH and SVV deviation were correlated and mostly unidirectional, but did not correspond to the side of motor symptom dominance. CONCLUSIONS: Visual verticality perception in PD is deviated already in early stages, conceivably as a relatively static internal misrepresentation of object orientation. Variability about verticality perception emerges in more advanced stages and is associated with postural and balance abnormalities.

Pilot multi-centre randomised trial of the impact of pre-operative focused cardiac ultrasound on mortality and morbidity in patients having surgery for femoral neck fractures (ECHONOF-2 pilot).

Hip fracture surgery is common, usually occurs in elderly patients who have multiple comorbidities, and is associated with high morbidity and mortality. Pre-operative focused cardiac ultrasound can alter diagnosis and management, but its impact on outcome remains uncertain. This pilot study assessed feasibility and group separation for a proposed large randomised clinical trial of the impact of pre-operative focused cardiac ultrasound on patient outcome after hip fracture surgery. Adult patients requiring hip fracture surgery in four teaching hospitals in Australia were randomly allocated to receive focused cardiac ultrasound before surgery or not. The primary composite outcome was any death, acute kidney injury, non-fatal myocardial infarction, cerebrovascular accident, pulmonary embolism or cardiopulmonary arrest within 30 days of surgery. Of the 175 patients screened, 100 were included as trial participants (screening:recruitment ratio 1.7:1), 49 in the ultrasound group and 51 as controls. There was one protocol failure among those recruited. The primary composite outcome occurred in seven of the ultrasound group patients and 12 of the control group patients (relative group separation 39%). Death, acute kidney injury and cerebrovascular accident were recorded, but no cases of myocardial infarction, pulmonary embolism or cardiopulmonary arrest ocurred. Focused cardiac ultrasound altered the management of 17 participants, suggesting an effect mechanism. This pilot study demonstrated that enrolment and the protocol are feasible, that the primary composite outcome is appropriate, and that there is a treatment effect favouring focused cardiac ultrasound - and therefore supports a large randomised clinical trial.

Age dependency of risk factors for cognitive decline.

BACKGROUND: Risk factors for cognitive decline might depend on chronological age. The aim of the study was to explore the age dependency of risk factors for cognitive decline in cognitively healthy subjects aged 55-85 years at baseline. METHODS: We included 2527 cognitively healthy subjects from the Longitudinal Aging Study Amsterdam (LASA). Median follow-up was 9.1 (IQR: 3.2-19.0) years. The association of genetic and cardiovascular risk factors, depressive symptoms, inflammation markers and lifestyle risk factors with decline in MMSE and memory function was tested using spline regression analyses. RESULTS: Subjects were on average 70.1 (SD 8.8) years old at baseline. Based on a spline regression model, we divided our sample in three age groups: ≤70 years (young-old), > 70-80 years (old) and > 80 years (oldest-old). The association of LDL cholesterol, homocysteine, hypertension, history of stroke, depressive symptoms, interleukin-6, a1-antichymotrypsin, alcohol use and smoking with cognitive decline significantly differed between the age groups. In general, the presence of these risk factors was associated with less cognitive decline in the oldest-old group compared to the young-old and old group. CONCLUSIONS: The negative effect of various risk factors on cognitive decline decreases with higher age. A combination of epidemiological factors, such as the selection towards healthier subjects during follow-up, but also risk factor specific features, for example ensuring the cerebral blood flow in case of hypertension, explain this diminished association at higher age. It is important to take these age differences into account when applying preventive strategies to avert cognitive decline.

Do older individuals who are diagnosed with cancer have worse physical performance prior to diagnosis compared to matched controls? A longitudinal cohort study.

BACKGROUND: Impaired physical performance is highly prevalent in older cancer patients and is associated with cancer-related outcomes such as mortality and chemotherapy-related toxicity. Physical performance might already decline prior to the cancer diagnosis due to undiagnosed disease. This study aimed to assess whether the physical performance of community-dwelling individuals prior to cancer diagnosis is worse compared to matched controls who are not diagnosed with cancer. METHODS: The study sample was selected from the Longitudinal Aging Study Amsterdam, a longitudinal study on a nationally representative sample of the Dutch older population. Physical performance of initially cancer-free individuals aged 55-84 years who were diagnosed with cancer during 10 or 20 years of follow-up was compared to the physical performance of controls who were not diagnosed with cancer. For controls, the physical performance measurements of the cycle with a median age closest to the cancer group were used. The time interval between physical performance measurements and the report of cancer was 2 to 4 years. Groups were compared using logistic and linear regression analysis. RESULTS: The study sample included 1735 individuals with a median age of 68.7 [interquartile range 63.3-76.4] years. During follow-up, 414 (23.9%) individuals were diagnosed with cancer. Handgrip strength, gait speed, chair stand ability, chair stand test time and ability to put on and take off a cardigan did not differ between groups. Individuals prior to cancer diagnosis were more likely to complete the tandem balance test. CONCLUSIONS: Physical performance of individuals 2 to 4 years prior to report of cancer diagnosis is not lower compared to controls. This suggests that physical performance may not be influenced by cancer before diagnosis.

[Merging different biobanks under one roof : Benefits and constraints on the way to a centralized biobank using the example of the BMBH]. / Alle unter einem Dach : Erfolge und Herausforderungen auf dem Weg zu einer zentralisierten Biobank am Beispiel der BMBH.

Founded in 1386, Heidelberg University is Germany's oldest and one of Europe's most reputable universities. As a scientific hub in Germany, Heidelberg is home to several internationally renowned medical research facilities that have an enormous demand for biomaterial samples and data-especially in the field of translational and cancer research.The main objective of the BMBF-funded project "BioMaterialBank Heidelberg" (BMBH) was the harmonization of local biobanking under the same administrative roof through the implementation of common and standardized project, data, and quality management procedures.In the very beginning, existing structures and processes of the participating biobanks in Heidelberg were identified and a common administrative structure with central representatives for IT and quality management (QM) was established to coordinate all BMBH activities.Over time, implementation of consented structures and processes took place, also revealing organizational challenges that had to be solved concerning, for example, differences in sample handling and the definition of consistent access regulations.We will discuss below these challenges as well as the opportunities of building a centralized biobank and show how issues can be resolved using the example of the BMBH.

[Osteomalacia-Clinical aspects, diagnostics and treatment]. / Osteomalazie ­ Klinik, Diagnostik und Therapie.

Osteomalacia is a bone disease caused by impaired skeletal mineralization. Vitamin D dependent types have to be distinguished from hypophosphatemic forms. Typical signs and symptoms include diffuse bone pain, muscle weakness and fragility fractures. The fracture pattern in osteomalacia is typically different from that of osteoporosis. Fragility fractures of the pelvis, sacrum, distal parts of the foot, proximal tibia and ribs are indicators for osteomalacia, whereas femoral neck and vertebral fractures (wedged vertebra, fish vertebra, vertebra plana and cover plate impression fractures) are typical for osteoporosis. Unspecific clinical features may be the reason for a delayed diagnosis. The correct classification of the complaint is dependent on the knowledge of the pathophysiology of osteomalacia and performance of additional bone-specific examinations. Determination of specific laboratory parameters should follow a rational algorithm, supplemented by imaging methods and a bone biopsy.

Circulating levels of dickkopf-1, osteoprotegerin and sclerostin are higher in old compared with young men and women and positively associated with whole-body bone mineral density in older adults.

Bone mineral density declines with increasing older age. We examined the levels of circulating factors known to regulate bone metabolism in healthy young and older adults. The circulating levels of dickkopf-1, osteocalcin, osteoprotegerin and sclerostin were positively associated with whole-body bone mineral density (WBMD) in older adults, despite the average WBMD being lower and circulating dickkopf-1, osteoprotegerin and sclerostin being higher in old than young. INTRODUCTION: This study aims to investigate the relationship between whole-body bone mineral density (WBMD) and levels of circulating factors with known roles in bone remodelling during 'healthy' ageing. METHODS: WBMD and fasting plasma concentrations of dickkopf-1, fibroblast growth factor-23, osteocalcin, osteoprotegerin, osteopontin and sclerostin were measured in 272 older subjects (69 to 81 years; 52% female) and 171 younger subjects (18-30 years; 53% female). RESULTS: WBMD was lower in old than young. Circulating osteocalcin was lower in old compared with young, while dickkopf-1, osteoprotegerin and sclerostin were higher in old compared with young. These circulating factors were each positively associated with WBMD in the older adults and the relationships remained after adjustment for covariates (r values ranging from 0.174 to 0.254, all p < 0.01). In multivariate regression, the body mass index, circulating sclerostin and whole-body lean mass together accounted for 13.8% of the variation with WBMD in the older adults. In young adults, dickkopf-1 and body mass index together accounted for 7.7% of variation in WBMD. CONCLUSION: Circulating levels of dickkopf-1, osteocalcin, osteoprotegerin and sclerostin are positively associated with WBMD in community-dwelling older adults, despite the average WBMD being lower and circulating dickkopf-1, osteoprotegerin and sclerostin being higher in old than young.

Chirp Mitigation of Plasma-Accelerated Beams by a Modulated Plasma Density.

Plasma-based accelerators offer the possibility to drive future compact light sources and high-energy physics applications. Achieving good beam quality, especially a small beam energy spread, is still one of the major challenges. Here, we propose to use a periodically modulated plasma density to shape the longitudinal fields acting on an electron bunch in the linear wakefield regime. With simulations, we demonstrate an on-average flat accelerating field that maintains a small beam energy spread.

Effects of functional endoscopic sinus surgery on the acoustics of the sinonasal tract.

BACKGROUND: Nasal and paranasal cavities are supposed to contribute substantially to the vocal tract resonator properties. However, their acoustical effects as well as the effects of sinus surgery on the voice remain unclear. In this work we investigate resonance phenomena of paranasal sinuses prior to and after various rhinosurgical procedures in cadaveric human sinonasal tracts and corresponding 3D casts. METHODOLOGY: Nasal and paranasal cavities of formalin-preserved cadavers and corresponding 3D replicas were excited by sine-tone sweeps from an earphone placed in the epipharynx. The response was picked up by a microphone at the nostrils. Different FESS procedures were performed and the acoustical responses following excitation were recorded. The measured acoustical changes in the obtained transfer functions were then evaluated. RESULTS: Marked low frequency dips were detected in the transfer functions when sinus cavities were included in the nasal resonator system. These dips showed a significant correlation with sinus volumes. Following FESS procedures they moved upwards in frequency depending on the extent of the surgical intervention. CONCLUSIONS: The transfer functions obtained in cadaveric situs and 3D replicas showed dips at the resonance frequencies of the paranasal cavities. Marked acoustic effects in terms of increase in dip frequency following FESS procedures were reproducibly documented.

Adaptation of multijoint coordination during standing balance in healthy young and healthy old individuals.

Standing balance requires multijoint coordination between the ankles and hips. We investigated how humans adapt their multijoint coordination to adjust to various conditions and whether the adaptation differed between healthy young participants and healthy elderly. Balance was disturbed by push/pull rods, applying two continuous and independent force disturbances at the level of the hip and between the shoulder blades. In addition, external force fields were applied, represented by an external stiffness at the hip, either stabilizing or destabilizing the participants' balance. Multivariate closed-loop system-identification techniques were used to describe the neuromuscular control mechanisms by quantifying the corrective joint torques as a response to body sway, represented by frequency response functions (FRFs). Model fits on the FRFs resulted in an estimation of time delays, intrinsic stiffness, reflexive stiffness, and reflexive damping of both the ankle and hip joint. The elderly generated similar corrective joint torques but had reduced body sway compared with the young participants, corresponding to the increased FRF magnitude with age. When a stabilizing or destabilizing external force field was applied at the hip, both young and elderly participants adapted their multijoint coordination by lowering or respectively increasing their neuromuscular control actions around the ankles, expressed in a change of FRF magnitude. However, the elderly adapted less compared with the young participants. Model fits on the FRFs showed that elderly had higher intrinsic and reflexive stiffness of the ankle, together with higher time delays of the hip. Furthermore, the elderly adapted their reflexive stiffness around the ankle joint less compared with young participants. These results imply that elderly were stiffer and were less able to adapt to external force fields.

Lateral Fasciectomy Sparing the Superficial Peroneal Nerve with Simultaneous Mesh Graft in Non-healing Lateral Leg Ulcers of Diverse Vascular Origins: Surgical Technique, Short- and Long-term Results from 44 Legs.

OBJECTIVES: The technique of lateral fasciectomy (LF) sparing the superficial peroneal nerve with mesh graft coverage is a novel treatment of non-healing lateral leg ulcers of various vascular origin affecting the fascia. We report short- and long-term results of LF for recalcitrant lateral leg ulcers. DESIGN: This study is a single center, retrospective case series of consecutive patients treated by LF. MATERIALS: From 827 ulcers treated at our institution, 44 recalcitrant lateral leg ulcers affecting the fascia (41 patients) underwent lateral fasciectomy between 2006 and 2013. METHODS: Preoperative indications, step-by-step surgical procedures, and perioperative care methodologies are presented. Long-term effects of healing and recurrence were clinically investigated or obtained through telephone interviews with relatives and local practitioners. RESULTS: Three discrete etiologies were identified: venous ulcers (n = 24), arterial-venous/mixed ulcers (n = 11), and arteriolar Martorell hypertensive leg ulcers (n = 9). Complete healing was achieved in 40 legs (91%) after 3 months, and in 43 of the affected legs (98%) in total. The median duration to complete healing was 64 days. There was no difference between the healing times of different etiologies. No local recurrence was observed during the follow-up period, which ranged from 1.8 to 8.7 years (median: 5.11, mean: 5.12). Twelve patients (27%) died within this period due to multimorbidity. CONCLUSIONS: Following lateral fasciectomy and mesh graft coverage, 43 legs (98%) healed in previously treatment resistant lateral leg ulcers.

Non-response to (statin) therapy: the importance of distinguishing non-responders from non-adherers in pharmacogenetic studies.

PURPOSE: In pharmacogenetic research, genetic variation in non-responders and high responders is compared with the aim to identify the genetic loci responsible for this variation in response. However, an important question is whether the non-responders are truly biologically non-responsive or actually non-adherent? Therefore, the aim of this study was to describe, within the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER), characteristics of both non-responders and high responders of statin treatment in order to possibly discriminate non-responders from non-adherers. METHODS: Baseline characteristics of non-responders to statin therapy (≤10 % LDL-C reduction) were compared with those of high responders (>40 % LDL-C reduction) through a linear regression analysis. In addition, pharmacogenetic candidate gene analysis was performed to show the effect of excluding non-responders from the analysis. RESULTS: Non-responders to statin therapy were younger (p = 0.001), more often smoked (p < 0.001), had a higher alcohol consumption (p < 0.001), had lower LDL cholesterol levels (p < 0.001), had a lower prevalence of hypertension (p < 0.001), and had lower cognitive function (p = 0.035) compared to subjects who highly responded to pravastatin treatment. Moreover, excluding non-responders from pharmacogenetic studies yielded more robust results, as standard errors decreased. CONCLUSION: Our results suggest that non-responders to statin therapy are more likely to actually be non-adherers, since they have more characteristics that are viewed as indicators of high self-perceived health and low disease awareness, possibly making the subjects less adherent to study medication. We suggest that in pharmacogenetic research, extreme non-responders should be excluded to overcome the problem that non-adherence is investigated instead of non-responsiveness.

Evaluation of self-swabbing coupled with a telephone health helpline as an adjunct tool for surveillance of influenza viruses in Ontario.

BACKGROUND: Calls to a telephone health helpline (THHL) have been previously evaluated for the ability to monitor specific syndromes, such as fever and influenza-like-illness or gastrointestinal illness. This method of surveillance has been shown to be highly correlated with traditional surveillance methods, and to have potential for early detection of community-based illness. Self-sampling, or having a person take his/her own nasal swab, has also proven successful as a useful method for obtaining a specimen, which may be used for respiratory virus detection. METHODS: This study describes a self-swabbing surveillance system mediated by a nurse-led THHL in Ontario whereby syndromic surveillance concepts are used to recruit and monitor participants with influenza-like illness. Once recruited, participants collect a nasal specimen obtained by self-swabbing and submit for testing and laboratory confirmation. Enumeration of weekly case counts was used to evaluate the timeliness of the self-swabbing surveillance system through comparison to other respiratory virus and influenza surveillance systems in Ontario. The operational efficiency of the system was also evaluated. RESULTS: The mean and median number of days between the day that a participant called the THHL, to the day a package was received at the laboratory for testing were approximately 10.4 and 8.6 days, respectively. The time between self-swab collection and package reception was 4.9 days on average, with a median of 4 days. The self-swabbing surveillance system adequately captured the 2014 influenza B season in a timely manner when compared to other Ontario-based sources of influenza surveillance data from the same year; however, the emergence of influenza B was not detected any earlier than with these other surveillance systems. Influenza A surveillance was also evaluated. Using the THHL self-swabbing system, a peak in the number of cases for influenza A was observed approximately one week after or during the same week as that reported by the other surveillance systems. CONCLUSION: This one-year pilot study suggests that the THHL self-swabbing surveillance system has significant potential as an adjunct tool for the surveillance of influenza viruses in Ontario. Recommendations for improving system efficacy are discussed.

The reason why orthopaedic surgeons perform total knee replacement: results of a randomised study using case vignettes.

PURPOSE: End-stage knee osteoarthritis (OA) results in total knee arthroplasty (TKA) surgery. The decision to perform TKA is not well defined, resulting in variation of indications among orthopaedic surgeons. Non-operative treatment measures are often not extensively used. Aim of this study was to investigate factors influencing the decision to perform TKA by Dutch orthopaedic surgeons. METHODS: Three case vignettes, each case divided into two versions, being identical except for information on age (younger and older age), pain (mild and severe pain) or radiological OA (low and high grade) were developed. A questionnaire including these three case vignettes was sent to 599 Dutch orthopaedic surgeons, who were randomised to either one of the two versions. The orthopaedic surgeons were asked whether TKA would be the next step in treatment. Furthermore, from a list of patient factors they were asked how strong these factors would influence the decision to perform TKA. RESULTS: 54 % of the orthopaedic surgeons completed the questionnaire (n = 326). Orthopaedic surgeons indicated to perform TKA significantly more often at higher age (73.3 vs. 45.5 %, p < 0.001). In the presence of mild pain, orthopaedic surgeons were slightly more reluctant to perform a TKA compared to severe pain (57.0 vs. 64.0 %, n.s.). Mild radiological OA made surgeons more reluctant to perform TKA compared to severe OA (9.7 vs. 96.9 %, p < 0.001). CONCLUSION: Old age and severe radiological OA are variables which are considered to be important in the decision to perform a TKA. Pain symptoms of moderate or severe pain are unequivocal when considering a TKA. LEVEL OF EVIDENCE: Economic/decision analysis, Level III.