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

Radiographic Biomarkers for Knee Osteoarthritis: A Narrative Review

Conventional radiography remains the most widely available imaging modality in clinical practice in knee osteoarthritis. Recent research has been carried out to develop novel radiographic biomarkers to establish the diagnosis and to monitor the progression of the disease. The growing number of publications on this topic over time highlights the necessity of a renewed review. Herein, we propose a narrative review of a selection of original full-text articles describing human studies on radiographic imaging biomarkers used for the prediction of knee osteoarthritis-related outcomes. To achieve this, a PubMed database search was used. A total of 24 studies were obtained and then classified based on three outcomes: (1) prediction of radiographic knee osteoarthritis incidence, (2) knee osteoarthritis progression and (3) knee arthroplasty risk. Results showed that numerous studies have reported the relevance of joint space narrowing score, Kellgren-Lawrence score and trabecular bone texture features as potential bioimaging markers in the prediction of the three outcomes. Performance results of reviewed prediction models were presented in terms of the area under the receiver operating characteristic curves. However, fair and valid comparisons of the models' performance were not possible due to the lack of a unique definition of each of the three outcomes.

Demographics are no clinically relevant predictors of patient-reported knee osteoarthritis symptoms - Comprehensive multivariate analysis

Aims & objectives

In clinical practice, arthroplasties are predominantly indicated by clinical and radiological assessment of osteoarthritis. Pain and function are individually considered, but a comprehensive analysis of differences in symptom reporting by pre-operative factors is lacking. In the present study, we determined differences in patient reported outcome measures between demographic groups among patients admitted to total knee arthroplasty.

Materials & methods

Between 2010 and 2019, we collected pre-operative Oxford Knee Scores, Western Ontario and McMaster University Osteoarthritis Index, quality of life in 2555 patients undergoing primary, osteoarthritis-indicated total knee arthroplasty at Patients were categorized by sex, age (<70, 70-80, >80 years), body mass index (BMI <25, 25-30, 30-35, >35 kg/m2), American Society of Anesthesiologists -classification (ASA 1, 2, ≥3) and Charnley score (A, B1, B2, C). Symptom scores (median, IQR) were compared using bivariate and multivariate methods.

Results

The cohort was 60% female, 70.0 years old (69.4-70.1), and BMI was 28.9 kg/m2 (29.6-30.0). As compared to bivariate analyses, between-group differences in multivariate analyses were consistently smaller. BMI and sex remain significant predictors after adjustment for age, ASA, and Charnley. Age, ASA, and Charnley were no independent predictors of symptom scores. A group of patients (30%) reported no physical dysfunction, and less symptom severity in pain and stiffness.

Conclusion

This study is the first to show that differences in symptom reporting between demographic groups are partly colinear, and are negligible for prediction of symptoms. Lastly, for a significant proportion of patients, patient-reported outcome measures do not adequately present disease severity.

Subchondral tibial bone texture of conventional X-rays predicts total knee arthroplasty

Lacking disease-modifying osteoarthritis drugs (DMOADs) for knee osteoarthritis (KOA), Total Knee Arthroplasty (TKA) is often considered an important clinical outcome. Thus, it is important to determine the most relevant factors that are associated with the risk of TKA. The present study aims to develop a model based on a combination of X-ray trabecular bone texture (TBT) analysis, and clinical and radiological information to predict TKA risk in patients with or at risk of developing KOA. This study involved 4382 radiographs, obtained from the OsteoArthritis Initiative (OAI) cohort. Cases were defined as patients with TKA on at least one knee prior to the 108-month follow-up time point and controls were defined as patients who had never undergone TKA. The proposed TKA-risk prediction model, combining TBT parameters and Kellgren–Lawrence (KL) grades, was performed using logistic regression. The proposed model achieved an AUC of 0.92 (95% Confidence Interval [CI] 0.90, 0.93), while the KL model achieved an AUC of 0.86 (95% CI 0.84, 0.86; p < 0.001). This study presents a new TKA prediction model with a good performance permitting the identification of at risk patient with a good sensitivy and specificity, with a 60% increase in TKA case prediction as reflected by the recall values.

Validation of a second-generation appropriateness classification system for total knee arthroplasty: a prospective cohort study

BACKGROUND

To test the validity of a second-generation appropriateness system in a cohort of patients undergoing total knee arthroplasty (TKA).

METHODS

We applied the RAND/UCLA Appropriateness Method to derive our second-generation system and conducted a prospective study of patients diagnosed with knee osteoarthritis in eight public hospitals in Spain. Main outcome questionnaires were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short-Form-12 (SF-12), and the Knee Society Score satisfaction scale (KSS), completed before and 6 months after TKA. Baseline, changes from baseline to 6 months (journey outcome), and 6-month scores (destination outcome) were compared according to appropriateness category. Percentage of patients attaining the minimal clinically important difference (MCID) and responders according to Outcome Measures in Rheumatology-Osteoarthritis Research Society (OMERACT-OARSI) criteria were also reported.

RESULTS

A total of 282 patients completed baseline and 6-month questionnaires. Of these, 142 (50.4%) were classified as Appropriate, 90 (31.9%) as Uncertain, and 50 (17.7%) as Inappropriate. Patients classified as Appropriate had worse preoperative pain, function, and satisfaction (p < 0.001) and had greater improvements (i.e., journey scores) than those classified as Inappropriate (p < 0.001). At 6 months, destination scores for pain, function, or satisfaction were not significantly different across appropriateness categories. The percentage of patients meeting responder criteria (p < 0.001) and attaining MCID was statistically higher in Appropriate versus Inappropriate groups in pain (p = 0.04) and function (p = 0.004).

CONCLUSIONS

The validity of our second-generation appropriateness system was generally supported. The findings highlight a critical issue in TKA healthcare: whether TKA appropriateness should be driven by the extent of improvement, by patient final state, or by both.

Recovery trajectories over six weeks in patients selected for a high-intensity physiotherapy program after Total knee Arthroplasty: a latent class analysis

Background

Recovery trajectories differ between individual patients and it is hypothesizes that they can be used to predict if an individual patient is likely to recover earlier or later. Primary aim of this study was to determine if it is possible to identify recovery trajectories for physical functioning and pain during the first six weeks in patients after TKA. Secondary aim was to explore the association of these trajectories with one-year outcomes.

Methods

Prospective cohort study of 218 patients with the following measurement time points: preoperative, and at three days, two weeks, six weeks, and one year post-surgery (no missings). Outcome measures were performance-based physical functioning (Timed Up and Go [TUG]), self-reported physical functioning (Knee injury and Osteoarthritis Outcome Score-Activities of Daily Living [KOOS-ADL]), and pain (Visual Analogue Scale [VAS]). Latent Class Analysis was used to distinguish classes based on recovery trajectories over the first six weeks postoperatively. Multivariable regression analyses were used to identify associations between classes and one year outcomes.

Results

TUG showed three classes: “gain group” (n = 203), “moderate gain group” (n = 8) and “slow gain group” (n = 7), KOOS showed two classes: “gain group” (n = 86) and “moderate gain group” (n = 132), and VAS-pain three classes: “no/very little pain” (n = 151), “normal decrease of pain” (n = 48) and “sustained pain” (n = 19). The” low gain group” scored 3.31 [95% CI 1.52, 5.09] seconds less on the TUG than the “moderate gain group” and the KOOS “gain group” scored 11.97 [95% CI 8.62, 15.33] points better than the “moderate gain group” after one year.

Patients who had an early trajectory of “sustained pain” had less chance to become free of pain at one year than those who reported “no or little pain” (odds ratio 0.11 [95% CI 0.03,0.42].

Conclusion

The findings of this study indicate that different recovery trajectories can be detected. These recovery trajectories can distinguish outcome after one year.

Which disease-related factors influence patients' and physicians' willingness to consider joint replacement in hip and knee OA? Results of a questionnaire survey linked to claims data

Background

A great heterogeneity in total joint replacement (TJR) rates has been reported for osteoarthritis (OA), most likely arising from a gap between patients’ and physicians’ views on the need for TJR. The purpose of this study therefore was to analyze potential cofactors which might influence the desire of patients to undergo TJR and physicians’ willingness to discuss surgery with their patients.

Methods

A total of 8995 patients in Germany with a claims data diagnosis of hip or knee OA or polyarthrosis were asked to complete a questionnaire for this cross-sectional study of sociodemographic factors, indicators of current joint function (WOMAC score), willingness to undergo TJR and whether they had already discussed TJR with a physician. The overall response rate was 40%. Responders with polyarthrosis and individuals without current or chronic symptoms in the corresponding joints, pain in already replaced joints or simultaneous symptomatic hip and knee OA were excluded. We linked the survey results to claims data. Separate logistic regression models were used to assess which parameters were associated with patients’ willingness to undergo TJR and physicians’ discussion of surgery.

Results

We analyzed 478 hip OA and 932 knee OA patients. Just 17% with hip OA and 14% with knee OA were willing to undergo TJR, although 44 and 45% had already discussed surgery with their physicians.

Patients’ willingness was associated with higher WOMAC scores, a deterioration of symptoms over the last 2 years, and previous TJR for another joint. The discussion with a physician was influenced by the impact on personal life and previous arthroplasty. Older age (odds Ratio (OR) 1.2 per 10 years), male sex (OR 0.69 vs female), longer symptom duration (OR 1.08 per 5 years), deterioration of symptoms (OR 2.0 vs no change/improvement), a higher WOMAC score (OR 1.3 per 10% deterioration) and reduced well-being (OR 1.1 per 10% deterioration) were associated with physician discussion in knee OA patients.

Conclusions

The proportion of patients willing to undergo TJR is lower than the proportion in whom physicians discuss surgery. While previous TJR seems to enhance patients’ and surgeons’ willingness, the influence of other cofactors is heterogeneous.

Predicting Total Knee Replacement from Symptomology and Radiographic Structural Change Using Artificial Neural Networks-Data from the Osteoarthritis Initiative (OAI)

The aim of the study was to longitudinally investigate symptomatic and structural factors prior to total knee replacement (TKR) surgery in order to identify influential factors that can predict a patient's need for TKR surgery. In total, 165 participants (60% females; 64.5 ± 8.4 years; 29.7 ± 4.7 kg/m²) receiving a TKR in any of both knees within a four-year period were analyzed. Radiographic change, knee pain, knee function and quality of life were annually assessed prior to the TKR procedure. Self-learning artificial neural networks were applied to identify driving factors for the surgical procedure. Significant worsening of radiographic structural change was observed prior to TKR (p ≤ 0.0046), whereas knee symptoms (pain, function, quality of life) worsened significantly only in the year prior to the TKR procedure. By using our prediction model, we were able to predict correctly 80% of the classified individuals to undergo TKR surgery with a positive predictive value of 84% and a negative predictive value of 73%. Our prediction model offers the opportunity to assess a patient's need for TKR surgery two years in advance based on easily available patient data and could therefore be used in a primary care setting.

A comparison of clinical and patient-reported outcome measures of TKR: Comparison of Asian to North American patients

BACKGROUND

Cultural differences between continents may also affect the outcome on interventions. This study compared an Asian and North American cohort of total knee replacement (TKR) patients.

QUESTIONS/PURPOSES

This study aims to compare the patient-reported outcome measures as well as a functional outcome after TKR between these two different patient populations with a different cultural societal background in two different countries.

PATIENTS AND METHODS

A retrospective study on two cohorts of 76 Asian TKR patients and 64 North American TKR patients were compared. Demographics, patient-reported outcome measures (Knee Society Score (KSS), Patient-Administered Questionnaire (PAQ), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)), knee range of motion (RoM), and radiographic component position were compared.

RESULTS

The Asian cohort had more females compared to the North American and significantly worse preoperative RoM, and worse KSS function score and PAQ pain scores. The preoperative KSS knee score and WOMAC scores were comparable between the two groups. Postoperatively, the differences in WOMAC and KSS knee scores were significant, while KSS function and PAQ were comparable between groups.

CONCLUSIONS

Even though Asian TKR patients had significantly worse preoperative scores, their postoperative outcomes were comparable to North Americans. The higher preoperative functional deficit and the higher pain levels in the Asian population might be due to cultural differences and/or socioeconomic reasons, which made Asian patients present with more severe conditions in the preoperative consultation for a possible surgical treatment compared to North Americans. More research is needed to investigate the difference between these cultural impacts on TKR outcomes.

LEVEL OF EVIDENCE

Level III/Retrospective cohort study.

A comparison of 4-year total medical care costs, adverse outcomes, and opioid/prescription analgesic use for 3 knee osteoarthritis pain treatments: Intra-articular hyaluronic acid, intra-articular corticosteroids, and knee arthroplasty

OBJECTIVES

To compare the medical costs associated with treatments for knee osteoarthritis (OA): intra-articular corticosteroids (ICS) and intra-articular hyaluronic acid (IHA) primarily, and ICS/IHA vs knee arthroplasty (TKA) secondarily.

METHODS

This was a retrospective analysis of an insurance claims database. Eligible members had diagnosed OA and no claims for ICS, IHA, or TKA during the 6-18-month look-back period. Cohorts of interest over the 4-year observation period were: patients who received ICS only, those who received IHA only, and those who received TKA only. Outcomes assessed included: (1) total allowed medical costs, (2) claims for pre-specified, treatment-related adverse outcomes and costs, and (3) opioid and/or prescription analgesic use and costs. Data extraction began on the date of the first ICS, IHA, or TKA in 2013 until December 31, 2017.

RESULTS

Of the 260,828 patients who qualified, 126,831 were taking monotherapy (IHA=3703, ICS=117,588, TKA = 5540). Adjusted 4-year per patient per month (PPPM) costs were lowest in the IHA cohort ($733); PPPM costs were $1230 in the ICS cohort and $1548 in the TKA cohort. A smaller percentage of patients in the IHA (7.1%) vs ICS (8.4%) or TKA cohort (11.8%) experienced any of the pre-specified adverse outcomes. Adverse outcome-related costs in the IHA cohort were lower ($19.91) than costs in the ICS ($32.18) and TKA cohorts ($31.12). Per-patient opioid and analgesic prescriptions were consistently and significantly lower in the IHA (range, 0.70-0.96) vs ICS cohort (range, 2.0-2.26) for Years 1 through 4. Usage rates were significantly lower in the IHA cohort vs TKA cohort in Year 1 (0.96 vs 4.77) and not different in Years 2 through 4 (TKA range, 0.76-1.08). In Year 1, opioid and prescription analgesic costs were significantly lower in the IHA vs ICS and TKA cohorts ($3.45 vs $11.14 and $12.82). After Year 1, opioid and prescription analgesic costs were significantly higher in the ICS (range, $13.83-15.96) vs IHA (range, $3.02-3.87) and TKA cohorts (range, $3.43-4.97).

CONCLUSIONS

Patients in the IHA cohort had lower total medical care costs, fewer adverse outcomes, and lower use/costs of opioids and prescription analgesics vs patients in the ICS and TKA cohorts. Reducing total medical care costs and minimizing opioid/analgesic use should be a treatment goal when selecting therapies for patients with knee OA.

Effects of low-intensity pulsed ultrasound on recovery of physical impairments, functional performance and quality of life after total knee arthroplasty: Protocol for a quasi-experimental study

INTRODUCTION

The presence of significant pain and swelling during the acute stage following total knee arthroplasty (TKA) may limit the patients' ability to cooperate in intensive physiotherapy interventions. Low-intensity pulsed ultrasound is one of the modalities that can be used for acute pain and swelling management. However, only one study investigated the effect of this modality in patients with TKA. There is limited documentation of the effects of combining low-intensity pulsed ultrasound in TKA rehabilitation in the recovery of physical impairments and how these influence the recovery of function after TKA. Therefore, this study is proposed with the aim to evaluate the effects of low-intensity pulsed ultrasound as an adjunct to conventional physiotherapy on the recovery of physical impairments, functional performance and quality of life after TKA surgery.

METHODS

This is an assessor-blinded quasi-experimental study comparing two approaches of physiotherapy, namely pulsed ultrasound-added physiotherapy and conventional physiotherapy. Total number of participants with TKA required for this study will be calculated based on the result of a pilot study. Participants will be alternately allocated into either pulsed ultrasound-added physiotherapy group (low-intensity pulsed ultrasound and conventional physiotherapy) or control group (conventional physiotherapy). Pulsed ultrasound-added physiotherapy group will receive low-intensity pulsed ultrasound starting at post-operative day 2 (4-5 times for the first-week after surgery and 2-3 times a week for a further 2 weeks). Both groups will receive conventional physiotherapy 4 to 5 times for the first-week after surgery and 2 to 3 times a week for a further 11 weeks. This procedure and process will be tested and established in a pilot study. Primary outcomes of interest are pain level, swelling, active range of knee motion, and quadriceps strength. The secondary outcomes are functional performance and quality of life.

DISCUSSION

This study will fill the gaps in knowledge relating the benefits of including low-intensity pulsed ultrasound into conventional physiotherapy for patients with TKA.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12618001226291.

From Early Radiographic Knee Osteoarthritis to Joint Arthroplasty: Determinants of Structural Progression and Symptoms

OBJECTIVE

To assess structural progression in knees with no/mild radiographic osteoarthritis (OA) (i.e., Kellgren/Lawrence [K/L] grades 0-2) that will undergo knee replacement during a 5-year period; to assess differences in structural damage on magnetic resonance imaging (MRI) in knees with no/mild radiographic OA versus those with severe radiographic OA (i.e., K/L grades 3 and 4) at baseline; and to assess differences in pain levels between those groups.

METHODS

All participants who underwent knee replacement from baseline to 60 months were drawn from the Osteoarthritis Initiative. MRIs were assessed for bone marrow lesions (BMLs), Hoffa synovitis, and effusion synovitis (i.e., hyperintensity signal changes in the fat pad and abnormal amount of capsular distension due to intraarticular joint fluid and/or synovial thickening) at baseline and at the time point before knee replacement (T0). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) pain were used for pain characterization. WOMAC activities of daily living and KOOS quality of life were applied to characterize functional status of the included participants. Logistic regression was used to assess the association of no/mild radiographic OA with these MRI features and pain.

RESULTS

Based on inclusion criteria, 181 knees were selected. Participants were predominantly female (57.8%) with a mean age of 64.4 years. A total of 51 knees (28.2%) had no/mild radiographic OA at baseline. Of these, 51.0% progressed to severe radiographic OA. No/mild radiographic OA knees showed higher odds of BMLs in the patellofemoral joint at baseline (odds ratio [OR] 7.92 [95% confidence interval (95% CI) 3.45-18.16]) and T0 (OR 9.44 [95% CI 4.00-22.28]) compared to severe radiographic OA knees. In addition, no/mild radiographic OA knees were associated with change from no pain to pain from baseline to T0 (adjusted OR 5.48 [95% CI 1.25-24.00]).

CONCLUSION

More than half of the knees with no/mild radiographic OA before knee replacement progressed to severe radiographic OA during 4 years of follow-up. BMLs in the patellofemoral joint were more often seen among knees that had no/mild radiographic OA. Worsening pain status may contribute to knee replacement in knees with no/mild radiographic OA.

How do orthopaedic surgeons inform their patients before knee arthroplasty surgery? A cross-sectional study

Background

Total knee arthroplasty (TKA) is a successful and common procedure. However, 6–28% of patients are dissatisfied postoperatively. The provision of preoperative patient information, inquiring about patients’ expectations, and taking a psychiatric history are essential parts of both preoperative evaluation and postoperative outcome. The aim of this study was to investigate how orthopaedic knee surgeons in Sweden inform their patients before surgery.

Methods

A questionnaire was distributed to all knee surgeons performing TKA in Sweden. Responses were received from 60 of the 65 orthopaedic departments performing TKA in Sweden (92%), covering 219 of the approximately 311 knee surgeons at the 65 departments (70%). The answers were analysed with descriptive statistics. A content analysis of the surgeons’ opinions was also performed using a thematic method.

Results

In terms of information provision, 58% of the surgeons always gave written information while 92% informed orally. Only 44% always asked about the patient’s expectations, and only 42% always informed patients about the 20% dissatisfaction rate after TKA. Additionally, 24% never operated on mild indication of arthrosis, 20% always took a psychiatric history, and half never or seldom consulted a psychiatrist. However, all the knee surgeons believed in a psychiatric impact on TKA outcome. Qualitative analysis revealed five common causes of patient dissatisfaction, which in descending frequency were: patients’ expectations, choice of patients to operate on, surgical factors, combinations of factors, and insufficient information provision to patients.

Conclusions

Knee surgeons in Sweden have considerable awareness of the importance of preoperative patient information, the impact of patient expectations, and psychiatric illness. However, they need to improve their preoperative routines when it comes to providing written information, asking about the patient’s expectations, and psychiatric assessment.

Factors associated with the orthopaedic surgeon's decision to recommend total joint replacement in hip and knee osteoarthritis: an international cross-sectional study of 1905 patients

OBJECTIVE

To determine factors associated with orthopaedic surgeons' decision to recommend total joint replacement (TJR) in people with knee and hip osteoarthritis (OA).

DESIGN

Cross-sectional study in eleven countries. For consecutive outpatients with definite hip or knee OA consulting an orthopaedic surgeon, the surgeon's indication of TJR was collected, as well as patients' characteristics including comorbidities and social situation, OA symptom duration, pain, stiffness and function (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), joint-specific quality of life, Osteoarthritis Research Society International (OARSI) joint space narrowing (JSN) radiographic grade (0-4), and surgeons' characteristics. Univariable and multivariable logistic regressions were performed to identify factors associated with the indication of TJR, adjusted by country.

RESULTS

In total, 1905 patients were included: mean age was 66.5 (standard deviation [SD], 10.8) years, 1082 (58.0%) were women, mean OA symptom duration was 5.0 (SD 7.0) years. TJR was recommended in 561/1127 (49.8%) knee OA and 542/778 (69.7%) hip OA patients. In multivariable analysis on 516 patients with complete data, the variables associated with TJR indication were radiographic grade (Odds Ratio, OR for one grade increase, for knee and hip OA, respectively: 2.90, 95% confidence interval [1.69-4.97] and 3.30 [2.17-5.03]) and WOMAC total score (OR for 10 points increase: 1.65 [1.32-2.06] and 1.38 [1.15-1.66], respectively). After excluding radiographic grade from the analyses, on 1265 patients, greater WOMAC total score was the main predictor for knee and hip OA; older age was also significant for knee OA.

CONCLUSION

Radiographic severity and patient-reported pain and function play a major role in surgeons' recommendation for TJR.

Are There Prognostic Factors for One-Year Outcome After Total Knee Arthroplasty? A Systematic Review

BACKGROUND

Preoperative factors predicting outcome for pain, physical function and quality of life after total knee arthroplasty (TKA) have not been clearly identified.

METHODS

Embase and MEDLINE were searched for relevant studies. A study was considered for inclusion if the study aimed to identify preoperative prognostic factors for pain, physical function, and/or quality of life after a follow-up period of at least 1 year; included at least 200 adults suffering from osteoarthritis and undergoing TKA; and analyzed data using multivariable modeling. The quality of the evidence per prognostic factor was determined using the Grading of Recommendations, Assessment, Development and Evaluation framework for prognosis studies.

RESULTS

A total of 18 studies were included. There is very low-quality evidence that preoperative more pain, presence of social support, absence of anxiety, and presence of more radiographic damage are prognostic factors for lower pain levels after TKA. There is very low-quality evidence that low preoperative physical function, less comorbidity, absence of anxiety, presence of social support, higher income, normal body mass index, and more radiographic damage are prognostic factors for better physical function. There is very low-quality evidence that female sex and less comorbidity are prognostic factors for better quality of life.

CONCLUSION

Only very low-quality evidence was found for a number of prognostic factors of long-term outcome after TKA. More studies that seek to generate understanding of the underlying process for the prognosis of outcome in TKA are needed to understand and test prognostic pathways, and it might be more valuable to look at recovery curves rather than at recovery points. Systematic review registration number: CRD42015026814.

Risk preferences and attitudes to surgery in decision making

Background and purpose - There is increasing evidence that several commonly performed surgical procedures provide little advantage over nonoperative treatment, suggesting that doctors may sometimes be inappropriately optimistic about surgical benefit when suggesting treatment for individual patients. We investigated whether attitudes to risk influenced the choice of operative treatment and nonoperative treatment. Methods - 946 Swedish orthopedic surgeons were invited to participate in an online survey. A radiograph of a 4-fragment proximal humeral fracture was presented together with 5 different patient characteristics, and the surgeons could choose between 3 different operative treatments and 1 nonoperative treatment. This was followed by an economic risk-preference test, and then by an instrument designed to measure 6 attitudes to surgery that are thought to be hazardous. We then investigated if choice of non-operative treatment was associated with risk aversion, and thereafter with the other variables, by regression analysis. Results - 388 surgeons responded. Nonoperative treatment for all cases was suggested by 64 of them. There was no significant association between risk aversion and tendency to avoid surgery. However, there was a statistically significant association between suggesting to operate at least 1 of the cases and a "macho" attitude to surgery or resignation regarding the chances of influencing the outcome of surgery. Choosing nonoperative treatment for all cases was associated with long experience as a surgeon. Interpretation - The discrepancy between available evidence for surgery and clinical practice does not appear to be related to risk preference, but relates to hazardous attitudes. It appears that choosing nonoperative treatment requires experience and a feeling that one can make a difference (i.e. a low score for resignation). There is a need for better awareness of available evidence for surgical indications.