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Review
Diagnostic accuracy of clinical tests for the diagnosis of hip femoroacetabular impingement/labral tear: a systematic review with meta-analysis
  1. M P Reiman1,2,
  2. A P Goode1,
  3. C E Cook1,
  4. P Hölmich3,4,
  5. K Thorborg3,5
  1. 1Department of Orthopedic Surgery, Duke University Medical Center, Durham, North Carolina, USA
  2. 2Duke University Medical Center, Durham, North Carolina, USA
  3. 3Sports Orthopedic Research Centre—Copenhagen (SORC-C), Arthroscopic Center Amager, Copenhagen University Hospital, Copenhagen, Denmark.
  4. 4Aspetar Sports Groin Pain Center, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
  5. 5Physical Medicine & Rehabilitation Research—Copenhagen (PMR-C), and Departments of Orthopaedic Surgery and Physical Therapy, Copenhagen University Hospital, Copenhagen, Denmark
  1. Correspondence to Dr Michael P Reiman, Department of Orthopedic Surgery, Duke University School of Medicine, DUMC 104002, Durham, NC 27710, USA; reiman.michael{at}gmail.com

Abstract

Background Surgery for hip femoroacetabular impingement/acetabular labral tear (FAI/ALT) is exponentially increasing despite lacking investigation of the accuracy of various diagnostic measures. Useful clinical utility of these measures is necessary to support diagnostic imaging and subsequent surgical decision-making.

Objective Summarise/evaluate the current diagnostic accuracy of various clinical tests germane to hip FAI/ALT pathology.

Methods A computer-assisted literature search of MEDLINE, CINAHL and EMBASE databases using keywords related to diagnostic accuracy of the hip joint, as well as the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for the search and reporting phases of the study. Quality assessment of bias and applicability was conducted using the Quality of Diagnostic Accuracy Studies-2 (QUADAS-2). Random effects models were used to summarise sensitivities (SN), specificities (SP), diagnostic odds ratio (DOR) and respective confidence intervals (CI).

Results The employed search strategy revealed 21 potential articles, with one demonstrating high quality. Nine articles qualified for meta-analysis. The meta-analysis demonstrated that flexion-adduction-internal rotation (pooled SN ranging from 0.94 (95% CI 0.90 to 0.97) to 0.99 (95% CI 0.98 to 1.00); DOR 5.71 (95% CI 0.84 to 38.86) to 7.82 (95% CI 1.06 to 57.84)) and flexion-internal rotation (pooled SN 0.96 (95% CI 0.81 to 0.99); DOR 8.36 (95% CI 0.41 to 171.3) tests possess only screening accuracy.

Conclusions Few hip physical examination tests for diagnosing FAI/ALT have been investigated in enough studies of substantial quality to direct clinical decision-making. Further high-quality studies across a wider spectrum of hip pathology patients are recommended to discern the confirmed clinical utility of these tests.

Trials registration number PROSPERO Registration # CRD42014010144.

  • Evaluation
  • Hip
  • Evidence based review
  • Groin
  • Injury

https://doi.org/10.1136/bjsports-2014-094302

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    Introduction

    Femoroacetabular impingement (FAI), an abnormal articulation and abutment of the femoral head against the acetabulum, is suggested to contribute to acetabular labral tear (ALT) and chondrolabral injury.1 The prevalence of ALT in patients with hip or groin pain ranges from 22% to 55%,2–5 although higher prevalence would be expected in a hip surgeon's consultancy.

    Surgery for the correction of FAI has increased significantly over the past decade.6 ,7 In fact, an 18-fold increase between 1999 and 2009 was shown in the USA.8 Given that differential diagnosis for the patient presenting with hip or groin pain is still suggested to be a diagnostic challenge,9 focus on proper diagnosis would seem warranted. A significant increase in attention has been shown for differential diagnosis of the hip joint and periarticular structures as the primary source for hip-related pain/dysfunction,10–14 although the principal focus is on radiographic imaging, and, to a lesser extent, clinical examination.15–17 The diagnostic accuracy of radiographic imaging for FAI/ALT,13 ,14 findings of radiographic asymmetries in asymptomatic individuals,18–44 as well as availability and cost of such imaging merits determination of the clinical utility of the clinical examination for FAI/ALT pathologies.

    While the diagnostic accuracy of hip physical examination (HPE) tests for FAI/ALT have previously been described,45–47 the estimation of test probability and, therefore, true clinical utility has not been synthesised. Therefore, the purpose of this study was to conduct a systematic review and meta-analysis of the literature regarding the diagnostic accuracy of HPE tests for FAI/ALT and describe their clinical utility.

    Methods

    Registration

    The study was registered on 6 August 2014 with the International Prospective Register of Systematic Reviews (PROSPERO# CRD42014010144). PROSPERO is a database of prospectively registered systematic reviews for health and social topics. The study was registered after pilot search and prior to updated data search and extraction.

    Data sources

    The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were utilised during the search and reporting phase of this review. The PRISMA statement includes a 27-item checklist that is designed to be used as a basis for reporting systematic reviews of randomised trials,48 but the checklist can also be applied to multiple forms of research methodologies.49

    A computer-assisted literature search of MEDLINE, CINAHL and EMBASE databases was performed from inception of each respective database to 10 June 2014. The goal was to optimise the sensitivity our search strategy,50 ,51 and to increase the likelihood that all appropriate studies were identified. The search strategy was developed in collaboration with a medical information specialist and used controlled vocabulary and key words related to diagnostic accuracy of the clinical examination measures relative to hip femoroacetabular impingement and labral tear.

    Screening filters were initially used during assessment of title, abstract and full text documents. The search was further limited to humans and English-only publications. The search strategy for MEDLINE is listed in online supplementary appendix 1.

    Selection criteria

    Articles examining clinical examination for FAI/ALT pathology were eligible if they met all of the following criteria: (1) included participants with hip pain suspected to be related to hip FAI/ALT, (2) included at least one clinical hip FAI/ALT pathology examination measure, (3) utilised an acceptable reference standard, (4) reported the results in sufficient detail to allow reconstruction of contingency tables to allow calculation of diagnostic accuracy metrics and (5) were written in English.

    An article was excluded if: (1) the pathology was associated with a condition located elsewhere (eg, lumbar spine) that referred pain to the hip region, (2) the clinical measures were performed under any form of anaesthesia or on cadavers, (3) specialised instrumentation not readily available to all clinicians were used, (4) physical clinical tests were included as a component of cluster tests, and (5) testing was performed on infants/toddlers.

    Data extraction

    Two reviewers (MPR, KT) independently performed the search. Since computerised search results for diagnostic accuracy data frequently omit many relevant articles,52 the reference lists of all selected publications were checked to retrieve relevant publications that were not identified in the computerised search. Grey literature was also manually searched and included publications, posters, abstracts or conference proceedings. To identify relevant articles, titles and abstracts of all identified citations were independently screened. Full-text articles were retrieved if the abstract provided insufficient information to establish eligibility or if the article passed the first eligibility screening.

    All criteria were independently applied by two reviewers (MPR, KT) to the full text of the articles that passed the first eligibility screening. Disagreements among the reviewers were discussed and resolved by a third reviewer (CEC). We determined which articles to include (for meta-analysis) using clinical and statistical judgement of study heterogeneity. Clinical judgment criteria involved assessment of similarity of populations, assessment context (eg, test performed a priori), study design (eg, case–control vs case based) and method in which specific tests were applied.53 In addition, after approval using clinical judgment, studies were statistically pooled when ≥2 studies examined the same index test and diagnosis with the same reference standard.

    Risk of bias/quality assessment

    Each of the full text articles was independently reviewed by two reviewers (MPR, CEC) and scored with the Quality Assessment of Diagnostic Accuracy Studies 2 scores (QUADAS-2) tool.54 Disagreements among the reviewers were discussed and resolved during a consensus meeting. The QUADAS-2 is a quality assessment tool comprised of four domains: patient selection, index test, reference standard, and flow and timing. The risk of bias is assessed in each of the domains, while the first three domains are also assessed for applicability by indicating a ‘low’, ‘high’ or ‘unclear’ rating. Applicability in the QUADAS-2 refers to whether certain aspects of an individual study are matching or not matching the review question. Unlike the QUADAS-1, the QUADAS-2 does not utilise a comprehensive quality score, rather an overall judgement of ‘low’, ‘high’ or ‘unclear’ risk. An overall risk rating of ‘low risk of bias’ or ‘low concern regarding applicability’ requires the study to be ranked as ‘low’ on all relevant domains. A ‘high’ or ‘unclear’ rating in one or more domains may require that the study be rated as an ‘at risk of bias’ or having ‘concerns regarding applicability.’

    Data extraction and analysis

    One reviewer (MPR) independently extracted information and data regarding study population, setting, special test performance, pathology, diagnostic reference-standard and number of true positives, false positives, false negatives and true negatives for calculation of sensitivity (SN), specificity (SP), positive likelihood ratios (+LR) and negative likelihood ratios (−LR) when not provided. SN is defined as the percentage of people who test positive for a specific pathology among a group of people who have the pathology. SP is the percentage of people who test negative for a specific pathology among a group of people who do not have the pathology. A positive likelihood ratio (+LR) is the ratio of a positive test result in people with the pathology to a positive test result in people without the pathology. A +LR identifies the strength of a test in determining the presence of a finding, and is calculated by the formula: SN/(1−SP). A negative likelihood ratio (−LR) is the ratio of a negative test result in people with the pathology to a negative test result in people without the pathology, and is calculated by the formula: (1−SN)/SP. The higher the +LR and lower the −LR the greater the post-test probability is altered. If analysed independently, tests that demonstrate high SN and low −LR are useful in ruling out a condition (screening). In contrast, tests that demonstrate high SP and high +LR assist in ruling in a condition (confirmation).55

    It has been suggested that post-test probability can be altered to a minimal degree with +LRs of 1– 2 or −LRs of 0.5–1, to a small degree with +LRs of 2–5 or −LRs of 0.2–0.5, to a moderate degree with +LRs of 5–10 and −LRs of 0.1–0.2) and to a large and almost conclusive degree with +LRs greater than 10 and −LRs less than 0.1.55 Pretest probability is defined as the probability of the target pathology before a diagnostic test result is known. It represents the probability that a specific patient, with a specific history, presenting to a specific clinical setting, with a specific symptom complex, has a specific pathology.55 The diagnostic odds ratio (DOR), defined as +LR/−LR, is a single indicator, independent of prevalence, which represents the ratio of the odds of positivity in disease relative to the odds or positivity in the non-diseased. The values for the DOR range from 0, indicating no test discrimination, to infinity with higher scores indicating better discrimination.56

    Meta-analysis

    DerSimonian and Laird57 random effects models, which incorporate both between and within study heterogeneity, were used to produce summary estimates of SN, SP, +LR, −LR, and diagnostic DOR. We initially attempted to analyse these data with a bivariate/hierarchical receiver operator curve model for those diagnostic tests with at least four studies. However, these models failed to converge and therefore report findings from the random effects models. An I-squared value of >50% and Cochrane's-Q p value of <0.10 were the criteria to indicate significant between-study heterogeneity, of SN and SP and likelihood ratios respectfully. Publication bias was not formally tested due to low power of the tests with limited included studies.58 No significant threshold effects were found using Spearman correlation coefficients. When a computational problem of empty cells existed, 0.5 was added to all four cells as suggested by Cox.59 Summary receiver operating characteristic (SROC) curves was produced when ≥4 studies were pooled. These curves summarise the diagnostic performance as a single number; the area under the curve (AUC) with a standard error (SE).60 AUC ≥0.90–1.00 were considered excellent, ≥0.80–90 considered good, ≥0.70–80 considered fair, ≥0.60–0.70 considered poor and ≥0.50–60 fail. Another measure, the Q* index and accompanied SE, is an additional measured produced which is the point on the SROC curve closest to the ideal left top-left corner (where SN and SP meet).61 All analyses were conducted by one of the authors (AG), blinded to results of the search, inclusion/exclusion and study quality, in Meta-DiSc V.1.4.62

    Results

    Selection of studies

    The systematic search through MEDLINE, CINAHL and EMBASE netted 340 abstracts, and 10 additional abstracts were identified through an extensive manual search. In total, 350 titles were initially retained after duplicates were removed. Abstract and full text review reduced the acceptable papers to 21 (figure 1 and table 1).

    View this table:
    Table 1

    Primary purpose(s) and risk of bias in included studies

    Figure 1
    Figure 1

    Flow diagram for study inclusion. IR, internal rotation; MA, meta-analysis; FADDIR, flexion adduction internal rotation test; MRA, MR arthrogram; RS, reference standard.

    This review included 1335 participants/1398 hips across 21 studies, investigating 11 different clinical special tests (tables 2 and 3). The sample size of the studies ranged from 1063 to 241 participants (table 2).64 Eight of the studies were retrospective,65–73 nine were prospective5 ,64 ,74–79 and the study design was unclear in four of the studies (table 1).3 ,63 ,80 ,81

    View this table:
    Table 2

    Demographics and characteristics of included studies

    View this table:
    Table 3

    Summary of articles reporting on the diagnostic accuracy of OSTs for hip impingement/labral tear tests

    Quality scores

    Table 1 provides the overall risk of bias score, with only one study80 demonstrating low risk of bias. It was unclear whether data collection was retrospective or prospective in this study.

    Results of individual diagnostic clinical measures

    Thirteen studies investigated the FADDIR test,65–69 ,71–73 ,75–77 ,79 ,81 three studies investigated the Flex-IR test,63 ,64 ,74 one study investigated the Bilateral lower extremity squat test,80 three studies investigated the FABER test,77–79 one study investigated the Scour test,78 one study investigated the IR with overpressure test,78 one study investigated the Resisted SLR test,78 one study investigated the Thomas test,3 one study investigated the THIRD test,70 one study investigated the IR-flexion-axial compression test,5 and one study investigated the Trochanteric tenderness test.77 Table 2 reports which tests each study investigated, as well as the characteristics of the study participants and the reference standard utilised. Table 3 reports the tests investigated, their diagnostic accuracy, reference standard utilised and the pretest to post-test probability change after use of the tests in each study for each test investigated.

    Meta-analysis

    Table 4 provides diagnostic properties and total sample sizes of the nine studies included in the meta-analysis. Four studies (n=188 participants)65 ,68 ,79 ,81 investigated the use of the FADDIR test with MR angiogram (MRA) reference standard, four studies (n=319 participants)68 ,69 ,71 ,76 investigated the use of the FADDIR test with surgery reference standard, and two studies (n=27 participants)63 ,74 investigated the use of the Flex IR test with surgery reference standard.

    View this table:
    Table 4

    Pooled diagnostic properties for the diagnosis of FAI/ALT

    Figures 2 and 3 illustrate the SROC curves for FADDIR test with MRA reference standard and surgery reference standard, respectively. This figure illustrates the relationship between SN and 1-SP (false-positive rate) for the included studies in pooled analyses. The AUC was considered fair (AUC=0.76 ((SE=0.19)) for the FADDIR with MRA reference and poor (AUC=0.65 ((SE=1.0)) for FADDIR with surgery reference. The point at which SN and SP were equal (Q*) was 0.70 (SE=0.19) the MRA reference standard and 0.61 (SE=0.81) for surgery reference standard.

    Figure 2
    Figure 2

    Summary receiver operating characteristic curve for FADDIR test (MRA reference standard).

    Figure 3
    Figure 3

    Summary receiver operating characteristic curve for FADDIR test (surgery reference standard).

    Figure 4 illustrates pretest to post-test probability changes utilising the FADDIR test with a surgery reference standard. Pretest to post-test probability for SN remained unchanged. Pretest to post-test probability demonstrated a notable shift, although the CIs were quite large.

    Figure 4
    Figure 4

    Nomogram demonstrating pretest to post-test probability changes (with CIs) after FADDIR test performance (surgery reference standard). Blue (top) line is post-test probability of diagnosis existing and red (bottom) line is post-test probability of diagnosis not existing.

    Discussion

    Our study examined the current literature investigating clinical examination tests for FAI/ALT. Owing to study heterogeneity and variable reference standards only two of the 11 different tests qualified for meta-analysis (FADDIR and Flexion IR tests). These, as well as most of the other tests, were predominantly only SN and not SP. Only two tests (in 9 studies) qualified for meta-analysis, and none of those tests significantly shifted post-test probability of the diagnosis of FAI/ALT. In fact, none of the tests investigated in our review is capable of significantly altering post-test probability. Additionally, the studies investigating all of the tests in our review, whether performed for the purpose of determining test diagnostic accuracy or not, were at risk for bias and low quality. A significant need for improved quality studies investigating these clinical tests exists.

    The purpose of performing clinical testing is to aid with determination of whether a particular pathology exists or not. When the clinician is appraising evidence about diagnostic tests they should consider several key concepts:55 ,82 did the participating individuals present a diagnostic dilemma? how much will different levels of the diagnostic test raise or lower the pretest probability of disease? will the reproducibility of the test result and its interpretation be satisfactory in my clinical setting? are the results applicable to the patients in my practice? will the test results change my management strategy? and will the patients be better off as a result of the test?

    Participants presenting to a clinicians practice with a diagnostic dilemma require utilisation of tests with properties capable of differentiating those with versus those without the disease. In order to properly assess these participants it is necessary to determine if they were drawn from a common group in which it is not known whether the condition of interest is present or absent.55 ,82 Participants in all 21 studies of this review were of high suspicion for various types of intra-articular joint pathology, most that were of high suspicion for FAI/ALT due to groin pain and/or other subjective symptoms (eg, clicking, catching) that are highly suggestive of these pathologies.3 ,5 ,68 The pretest probability in the investigated tests ranged from 17%5 to 94%,79 but was higher than 55% in all but five studies5 ,64 ,77 ,78 ,80 involving 10 of the 28 tests listed in table 3. Certainly, a high pretest probability can influence the likelihood of reporting a positive finding on the tests and this may be a reason we found high SN in the tests that were eligible for meta-analysis.

    The single largest increase in post-test probability (in studies of low bias) after use of a particular test was only 6.1% when utilising the painful squat test by Ayeni et al80 Most other tests investigated in this review provided very small percentage increases in post-test probability. In fact, in meta-analysis calculations (table 4), there were minimal to no increases in post-test probabilities, ranging from 1% decline in probability when using the FADDIR test (MRA reference standard), no change using the FADDIR test (surgical reference standard; figure 2), and 3% increase using the Flexion IR test with MRA reference standard. While the post-test probability could change significantly with, for example, the FADDIR test to rule out the pathology existing, the wide range CIs limit the accuracy of interpretation of these findings (figure 4). Additionally, having these test performed on participants of high suspicion of pathology results in scarce true negative findings in these studies.

    Ascertaining results of the tests investigated in this review strongly suggests limitations in their clinical utility. The results of these tests appear to minimally change the clinician's treatment strategy, and the participants do not appear to be better off as a result of performing these tests. The current scope of literature investigating these tests is narrow in its focus (examining participants with high suspicion of pathology prior to test performance) and, therefore, results in test results of high SN, poor SP and limited post-test probability in determining the diagnosis of FAI/ALT. In fact, a clinician practising in an orthopaedic/sports clinic seeing participants with high suspicion of FAI/ALT would benefit minimally by performing these tests.

    An additional concern regarding diagnostic accuracy studies is the potential for bias. Only one of the included studies in this review had low risk of bias.80 This study investigated a newly described test (bilateral lower extremity squat to maximum depth). Using a sample size of 76 participants, a SN of 75 and a SP of 41, this test was found to also provide the greatest shift in pretest to post-test probability (6.1%). As mentioned previously, the large majority of these tests had much greater pretest probabilities prior to test implementation than this test. This study utilised the more potentially biased reference standard of MRI and/or MRA.

    Although MRI/MRA is rightfully not considered the ‘gold standard’ for these studies, the use of surgery alone leads to biased participant sampling. Determination of the clinical utility of these tests requires their implementation in future studies across the spectrum of participants with and without undetermined hip pathology. The reference standard for these studies would thus be the more imprecise MRI/MRA. Although the diagnostic accuracy of MRI/MRA currently is limited,13 limiting image reading to those with specialist training,83 utilisation of precise, tailored protocols84 and improving imaging technology could afford suitability for MRI/MRA as acceptable reference standards for these participants. Implementation of these tests across this broad continuum of hip participants is paramount to determine their actual clinical utility.

    Limitations

    Limitations of this study include: limiting the search strategy to only those articles written in English, one author pulling the data points, lack of comparison of participant inclusion and exclusion across the studies and studies performed in settings of high pretest probability. Limiting to English language could potentially miss some studies to be included in our review. Only one author pulling the data points increases the risk of potential error, although this author (MPR) has pulled many of these data points for a similar review of both intra-articular and extra-articular hip pathology.85 Since many of the included studies were published prior to prospective guidelines for diagnostic accuracy studies, the robustness of reporting inclusion/exclusion criteria was highly variable among the studies and very difficult to comprehensively describe in this review. Having these studies performed in hip surgeon clinical settings is a limitation of the current literature that is uncontrollable by the authors of this review.

    Conclusion

    Owing to the low quality and biased sampling of patients with high probability of disease, hip physical examination tests do not appear to currently provide the clinician any significant value in altering probability of disease with their use. Currently, only the FADDIR and Flex-IR tests are supported by the data as valuable screening tests for FAI/LT pathology. Further studies involving high quality designs across a wider spectrum of hip pathology patients are necessary to discern the confirmed clinical utility of these tests.

    What are the new findings

    • Few hip clinical tests, as investigated in current studies, actually make a significant change in post-test probability for the potential of femoroacetabular impingement/acetabular labral tear (FAI/ALT) existing.

    • These clinical tests, when utilised in clinical settings of high pretest probability, will provide the practising clinician with limited to no assistance in determination of the presence or absence of FAI/ALT.

    • Prospective studies examining clinical utility of these tests in patients with/without various hip pathologies are not available, but suggested.

    Acknowledgments

    The authors would like to thank Leila Ledbetter, MLIS for assisting with the literature search for this study.

    References

    1. ↵
      1. Ganz R,
      2. Parvizi J,
      3. Beck M, et al
      . Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop Relat Res 2003;417:112–20.
      OpenUrlPubMed
    2. ↵
      1. McCarthy JC,
      2. Noble PC,
      3. Schuck MR, et al
      . The Otto E. Aufranc Award: the role of labral lesions to development of early degenerative hip disease. Clin Orthop Relat Res 2001;393:25–37. doi:10.1097/00003086-200112000-00004
      OpenUrlCrossRefPubMed
    3. ↵
      1. McCarthy JC,
      2. Busconi B
      . The role of hip arthroscopy in the diagnosis and treatment of hip disease. Orthopedics 1995;18:753–6.
      OpenUrlPubMedWeb of Science
    4. ↵
      1. Lewis CL,
      2. Sahrmann SA,
      3. Moran DW
      . Anterior hip joint force increases with hip extension, decreased gluteal force, or decreased iliopsoas force. J Biomech 2007;40:3725–31. doi:10.1016/j.jbiomech.2007.06.024
      OpenUrlCrossRefPubMedWeb of Science
    5. ↵
      1. Narvani AA,
      2. Tsiridis E,
      3. Kendall S, et al
      . A preliminary report on prevalence of acetabular labrum tears in sports patients with groin pain. Knee Surg Sports Traumatol Arthrosc 2003;11:403–8. doi:10.1007/s00167-003-0390-7
      OpenUrlCrossRefPubMedWeb of Science
    6. ↵
      1. Montgomery SR,
      2. Ngo SS,
      3. Hobson T, et al
      . Trends and demographics in hip arthroscopy in the United States. Arthroscopy 2013;22:661–5. doi:10.1016/j.arthro.2012.11.005
      OpenUrl
    7. ↵
      1. Lee YK,
      2. Ha YC,
      3. Yoon BH, et al
      . National trends of hip arthroscopy in Korea. J Korean Med Sci 2014;29:277–80. doi:10.3346/jkms.2014.29.2.277
      OpenUrlCrossRefPubMed
    8. ↵
      1. Colvin AC,
      2. Harrast J,
      3. Harner C
      . Trends in hip arthroscopy. J Bone Joint Surg Am 2012;94:e23.
      OpenUrlAbstract/FREE Full Text
    9. ↵
      1. Reiman MP,
      2. Mather RC III.,
      3. Hash TW II., et al
      . Examination of acetabular labral tear: a continued diagnostic challenge. Br J Sports Med 2013;48:311–19. doi:10.1136/bjsports-2012-091994
      OpenUrlPubMed
    10. ↵
      1. Byrd JW,
      2. Jones KS
      . Diagnostic accuracy of clinical assessment, magnetic resonance imaging, magnetic resonance arthrography, and intra-articular injection in hip arthroscopy patients. Am J Sports Med 2004;32:1668–74. doi:10.1177/0363546504266480
      OpenUrlAbstract/FREE Full Text
    11. ↵
      1. McCarthy JC,
      2. Busconi BD,
      3. Owens BD
      . Assessment of the painful hip. In: MCCarthy JC, ed. Early hip disorders. New York: Springer, 2003:7–8.
    12. ↵
      1. Tibor LM,
      2. Sekiya JK
      . Differential diagnosis of pain around the hip joint. Arthroscopy 2008;24:1407–21. doi:10.1016/j.arthro.2008.06.019
      OpenUrlCrossRefPubMedWeb of Science
    13. ↵
      1. Smith TO,
      2. Hilton G,
      3. Toms AP, et al
      . The diagnostic accuracy of acetabular labral tears using magnetic resonance imaging and magnetic resonance arthrography: a meta-analysis. Eur Radiol 2010;21:863–74. doi:10.1007/s00330-010-1956-7
      OpenUrlPubMed
    14. ↵
      1. Smith TO,
      2. Simpson M,
      3. Ejindu V, et al
      . The diagnostic test accuracy of magnetic resonance imaging, magnetic resonance arthrography and computer tomography in the detection of chondral lesions of the hip. Eur J Orthop Surg Traumatol 2013;23:335–44. doi:10.1007/s00590-012-0972-5
      OpenUrlCrossRefPubMed
    15. ↵
      1. Ayeni OR,
      2. Wong I,
      3. Chien T, et al
      . Surgical indications for arthroscopic management of femoroacetabular impingement. Arthroscopy 2012;28:1170–9. doi:10.1016/j.arthro.2012.01.010
      OpenUrlCrossRefPubMed
    16. ↵
      1. Hetaimish BM,
      2. Khan M,
      3. Crouch S, et al
      . Consistency of reported outcomes after arthroscopic management of femoroacetabular impingement. Arthroscopy 2013;29:780–7. doi:10.1016/j.arthro.2012.11.011
      OpenUrlCrossRefPubMed
    17. ↵
      1. Ayeni OR,
      2. Belzile EL,
      3. Musahl V, et al
      . Results of the PeRception of femOroaCetabular impingEment by Surgeons Survey (PROCESS). Knee Surg Sports Traumatol Arthrosc 2014;22:906–10. doi:10.1007/s00167-014-2882-z
      OpenUrlCrossRefPubMed
    18. ↵
      1. Register B,
      2. Pennock AT,
      3. Ho CP, et al
      . Prevalence of abnormal hip findings in asymptomatic participants: a prospective, blinded study. Am J Sports Med 2012;40:2720–4. doi:10.1177/0363546512462124
      OpenUrlAbstract/FREE Full Text
    19. ↵
      1. Schmitz MR,
      2. Campbell SE,
      3. Fajardo RS, et al
      . Identification of acetabular labral pathological changes in asymptomatic volunteers using optimized, noncontrast 1.5-T magnetic resonance imaging. Am J Sports Med 2012;40:1337–41. doi:10.1177/0363546512439991
      OpenUrlAbstract/FREE Full Text
    20. ↵
      1. Silvis ML,
      2. Mosher TJ,
      3. Smetana BS, et al
      . High prevalence of pelvic and hip magnetic resonance imaging findings in asymptomatic collegiate and professional hockey players. Am J Sports Med 2011;39:715–21. doi:10.1177/0363546510388931
      OpenUrlAbstract/FREE Full Text
    21. ↵
      1. Abe I,
      2. Harada Y,
      3. Oinuma K, et al
      . Acetabular labrum: abnormal findings at MR imaging in asymptomatic hips. Radiology 2000;216:576–81. doi:10.1148/radiology.216.2.r00au13576
      OpenUrlCrossRefPubMedWeb of Science
    22. ↵
      1. Aydingoz U,
      2. Ozturk MH
      . MR imaging of the acetabular labrum: a comparative study of both hips in 180 asymptomatic volunteers. Eur Radiol 2001;11:567–74. doi:10.1007/s003300000597
      OpenUrlCrossRefPubMedWeb of Science
    23. ↵
      1. Lecouvet FE,
      2. Vande Berg BC,
      3. Malghem J, et al
      . MR imaging of the acetabular labrum: variations in 200 asymptomatic hips. AJR Am J Roentgenol 1996;167:1025–8. doi:10.2214/ajr.167.4.8819406
      OpenUrlCrossRefPubMedWeb of Science
    24. ↵
      1. Cotten A,
      2. Boutry N,
      3. Demondion X, et al
      . Acetabular labrum: MRI in asymptomatic volunteers. J Comput Assist Tomogr 1998;22:1–7. doi:10.1097/00004728-199801000-00001
      OpenUrlPubMedWeb of Science
    25. ↵
      1. Nepple JJ,
      2. Brophy RH,
      3. Matava MJ, et al
      . Radiographic findings of femoroacetabular impingement in national football league combine athletes undergoing radiographs for previous hip or groin pain. Arthroscopy 2012;28:1396–403. doi:10.1016/j.arthro.2012.03.005
      OpenUrlCrossRefPubMed
    26. ↵
      1. Kapron AL,
      2. Anderson AE,
      3. Aoki SK, et al
      . Radiographic prevalence of femoroacetabular impingement in collegiate football players: AAOS exhibit selection. J Bone Joint Surg Am 2011;93:e111(1–10). doi:10.2106/JBJS.K.00544
      OpenUrlAbstract/FREE Full Text
    27. ↵
      1. Khanna V,
      2. Caragianis A,
      3. Diprimio G, et al
      . Incidence of hip pain in a prospective cohort of asymptomatic volunteers: is the cam deformity a risk factor for hip pain? Am J Sports Med 2014;42:793–7. doi:10.1177/0363546513518417
      OpenUrlAbstract/FREE Full Text
    28. ↵
      1. Ergen FB,
      2. Vudali S,
      3. Sanverdi E, et al
      . CT assessment of asymptomatic hip joints for the background of femoroacetabular impingement morphology. Diagn Interv Radiol 2014;20:271–6. doi:10.5152/dir.2013.13374
      OpenUrlCrossRefPubMed
    29. ↵
      1. Chakraverty JK,
      2. Sullivan C,
      3. Gan C, et al
      . Cam and pincer femoroacetabular impingement: CT findings of features resembling femoroacetabular impingement in a young population without symptoms. AJR Am J Roentgenol 2013;200:389–95. doi:10.2214/AJR.12.8546
      OpenUrlCrossRefPubMedWeb of Science
    30. ↵
      1. Joo JH,
      2. Lee SC,
      3. Ahn HS, et al
      . Evaluation of the alpha angle in asymptomatic adult hip joints: analysis of 994 hips. Hip Int 2013;23:395–9. doi:10.5301/hipint.5000036
      OpenUrlCrossRefPubMedWeb of Science
    31. ↵
      1. Jung KA,
      2. Restrepo C,
      3. Hellman M, et al
      . The prevalence of cam-type femoroacetabular deformity in asymptomatic adults. J Bone Joint Surg Br 2011;93:1303–7. doi:10.1302/0301-620X.93B10.26433
      OpenUrlCrossRefPubMed
    32. ↵
      1. Hack K,
      2. Di Primio G,
      3. Rakhra K, et al
      . Prevalence of cam-type femoroacetabular impingement morphology in asymptomatic volunteers. J Bone Joint Surg Am 2010;92:2436–44. doi:10.2106/JBJS.J.01280
      OpenUrlAbstract/FREE Full Text
    33. ↵
      1. Bixby SD,
      2. Kienle KP,
      3. Nasreddine A, et al
      . Reference values for proximal femoral anatomy in adolescents based on sex, physis, and imaging plane. Am J Sports Med 2013;41:2074–82. doi:10.1177/0363546513495346
      OpenUrlAbstract/FREE Full Text
    34. ↵
      1. Yuan BJ,
      2. Bartelt RB,
      3. Levy BA, et al
      . Decreased range of motion is associated with structural hip deformity in asymptomatic adolescent athletes. Am J Sports Med 2013;41:1519–25. doi:10.1177/0363546513488748
      OpenUrlAbstract/FREE Full Text
    35. ↵
      1. Klingenstein GG,
      2. Zbeda RM,
      3. Bedi A, et al
      . Prevalence and preoperative demographic and radiographic predictors of bilateral femoroacetabular impingement. Am J Sports Med 2013;41:762–8. doi:10.1177/0363546513476854
      OpenUrlAbstract/FREE Full Text
    36. ↵
      1. Reichenbach S,
      2. Leunig M,
      3. Werlen S, et al
      . Association between cam-type deformities and magnetic resonance imaging-detected structural hip damage: a cross-sectional study in young men. Arthritis Rheum 2011;63:4023–30. doi:10.1002/art.30589
      OpenUrlCrossRefPubMedWeb of Science
    37. ↵
      1. Reichenbach S,
      2. Juni P,
      3. Werlen S, et al
      . Prevalence of cam-type deformity on hip magnetic resonance imaging in young males: a cross-sectional study. Arthritis Care Res 2010;62:1319–27. doi:10.1002/acr.20198
      OpenUrlWeb of Science
    38. ↵
      1. Sutter R,
      2. Dietrich TJ,
      3. Zingg PO, et al
      . How useful is the alpha angle for discriminating between symptomatic patients with cam-type femoroacetabular impingement and asymptomatic volunteers? Radiology 2012;264:514–21. doi:10.1148/radiol.12112479
      OpenUrlCrossRefPubMedWeb of Science
    39. ↵
      1. Sutter R,
      2. Dietrich TJ,
      3. Zingg PO, et al
      . Femoral antetorsion: comparing asymptomatic volunteers and patients with femoroacetabular impingement. Radiology 2012;263:475–83. doi:10.1148/radiol.12111903
      OpenUrlCrossRefPubMedWeb of Science
    40. ↵
      1. Hartofilakidis G,
      2. Bardakos NV,
      3. Babis GC, et al
      . An examination of the association between different morphotypes of femoroacetabular impingement in asymptomatic subjects and the development of osteoarthritis of the hip. J Bone Joint Surg Br 2011;93:580–6. doi:10.1302/0301-620X.93B5.25236
      OpenUrlCrossRefPubMed
    41. ↵
      1. Kang AC,
      2. Gooding AJ,
      3. Coates MH, et al
      . Computed tomography assessment of hip joints in asymptomatic individuals in relation to femoroacetabular impingement. Am J Sports Med 2010;38:1160–5. doi:10.1177/0363546509358320
      OpenUrlAbstract/FREE Full Text
    42. ↵
      1. Weir A,
      2. de Vos RJ,
      3. Moen M, et al
      . Prevalence of radiological signs of femoroacetabular impingement in patients presenting with long-standing adductor-related groin pain. Br J Sports Med 2011;45:6–9. doi:10.1136/bjsm.2009.060434
      OpenUrlAbstract/FREE Full Text
    43. ↵
      1. Allen D,
      2. Beaule PE,
      3. Ramadan O, et al
      . Prevalence of associated deformities and hip pain in patients with cam-type femoroacetabular impingement. J Bone Joint Surg Br 2009;91:589–94. doi:10.1302/0301-620X.91B5.22028
      OpenUrlCrossRefPubMedWeb of Science
    44. ↵
      1. Schmitz MR,
      2. Bittersohl B,
      3. Zaps D, et al
      . Spectrum of radiographic femoroacetabular impingement morphology in adolescents and young adults: an EOS-based double-cohort study. J Bone Joint Surg Am 2013;95:e90. doi:10.2106/JBJS.L.01030
      OpenUrlAbstract/FREE Full Text
    45. ↵
      1. Leibold MR,
      2. Huijbregts PA,
      3. Jensen R
      . Concurrent criterion-related validity of physical examination tests for hip labral lesions: a systematic review. J Man Manip Ther 2008;16:E24–41. doi:10.1179/jmt.2008.16.2.24E
      OpenUrlCrossRefPubMed
    46. ↵
      1. Burgess RM,
      2. Rushton A,
      3. Wright C, et al
      . The validity and accuracy of clinical diagnostic tests used to detect labral pathology of the hip: a systematic review. Man Ther 2011;16:318–26. doi:10.1016/j.math.2011.01.002
      OpenUrlCrossRefPubMed
    47. ↵
      1. Tijssen M,
      2. van Cingel R,
      3. Willemsen L, et al
      . Diagnostics of femoroacetabular impingement and labral pathology of the hip: a systematic review of the accuracy and validity of physical tests. Arthroscopy 2012;28:860–71. doi:10.1016/j.arthro.2011.12.004
      OpenUrlCrossRefPubMed
    48. ↵
      1. Moher D,
      2. Liberati A,
      3. Tetzlaff J, et al
      . Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Int J Surg 2010;8:336–41. doi:10.1016/j.ijsu.2010.02.007
      OpenUrlCrossRefPubMed
    49. ↵
      1. Swartz MK
      . The PRISMA statement: a guideline for systematic reviews and meta-analyses. J Pediatr Health Care 2011;25:1–2. doi:10.1016/j.pedhc.2010.09.006
      OpenUrlCrossRefPubMedWeb of Science
    50. ↵
      1. Wilczynski NL,
      2. Haynes RB
      . Developing optimal search strategies for detecting clinically sound prognostic studies in MEDLINE: an analytic survey. BMC Med 2004;2:23. doi:10.1186/1741-7015-2-23
      OpenUrlCrossRefPubMed
    51. ↵
      1. Wilczynski NL,
      2. Haynes RB
      . Optimal search strategies for detecting clinically sound prognostic studies in EMBASE: an analytic survey. J Am Med Inform Assoc 2005;12:481–5. doi:10.1197/jamia.M1752
      OpenUrlAbstract/FREE Full Text
    52. ↵
      1. Doust JA,
      2. Pietrzak E,
      3. Sanders S, et al
      . Identifying studies for systematic reviews of diagnostic tests was difficult due to the poor sensitivity and precision of methodologic filters and the lack of information in the abstract. J Clin Epidemiol 2005;58:444–9. doi:10.1016/j.jclinepi.2004.09.011
      OpenUrlCrossRefPubMed
    53. ↵
      1. Akobeng AK
      . Understanding systematic reviews and meta-analysis. Arch Dis Child 2005;90:845–8. doi:10.1136/adc.2004.058230
      OpenUrlAbstract/FREE Full Text
    54. ↵
      1. Whiting PF,
      2. Rutjes AW,
      3. Westwood ME, et al
      . QUADAS-2: a revised tool for the quality assessment of diagnostic accuracy studies. Ann Intern Med 2011;155:529–36. doi:10.7326/0003-4819-155-8-201110180-00009
      OpenUrlCrossRefPubMedWeb of Science
    55. ↵
      1. Jaeschke R,
      2. Guyatt GH,
      3. Sackett DL
      . Users’ guides to the medical literature. III. How to use an article about a diagnostic test. B. What are the results and will they help me in caring for my patients? The evidence-based medicine working group. JAMA 1994;271:703–7. doi:10.1001/jama.1994.03510330081039
      OpenUrlCrossRefPubMedWeb of Science
    56. ↵
      1. Glas AS,
      2. Lijmer JG,
      3. Prins MH, et al
      . The diagnostic odds ratio: a single indicator of test performance. J Clin Epidemiol 2003;56:1129–35. doi:10.1016/S0895-4356(03)00177-X
      OpenUrlCrossRefPubMedWeb of Science
    57. ↵
      1. DerSimonian R,
      2. Laird N
      . Meta-analysis in clinical trials. Control Clin Trials 1986;7:177–88. doi:10.1016/0197-2456(86)90046-2
      OpenUrlCrossRefPubMedWeb of Science
    58. ↵
      1. Sterne JA,
      2. Gavaghan D,
      3. Egger M
      . Publication and related bias in meta-analysis: power of statistical tests and prevalence in the literature. J Clin Epidemiol 2000;53:1119–29. doi:10.1016/S0895-4356(00)00242-0
      OpenUrlCrossRefPubMedWeb of Science
    59. ↵
      1. Cox D
      . The analysis of binary data. London: Methuen, 1970.
    60. ↵
      1. Hanley JA,
      2. McNeil BJ
      . The meaning and use of the area under a receiver operating characteristic (ROC) curve. Radiology 1982;143:29–36. doi:10.1148/radiology.143.1.7063747
      OpenUrlCrossRefPubMedWeb of Science
    61. ↵
      1. Walter SD
      . Properties of the summary receiver operating characteristic (SROC) curve for diagnostic test data. Stat Med 2002;21:1237–56. doi:10.1002/sim.1099
      OpenUrlCrossRefPubMedWeb of Science
    62. ↵
      1. Zamora J,
      2. Abraira V,
      3. Muriel A, et al
      . Meta-DiSc: a software for meta-analysis of test accuracy data. BMC Med Res Methodol 2006;6:31. doi:10.1186/1471-2288-6-31
      OpenUrlCrossRefPubMed
    63. ↵
      1. Petersilge CA,
      2. Haque MA,
      3. Petersilge WJ, et al
      . Acetabular labral tears: evaluation with MR arthrography. Radiology 1996;200:231–5. doi:10.1148/radiology.200.1.8657917
      OpenUrlCrossRefPubMedWeb of Science
    64. ↵
      1. Nogier A,
      2. Bonin N,
      3. May O, et al
      . Descriptive epidemiology of mechanical hip pathology in adults under 50 years of age. Prospective series of 292 cases: clinical and radiological aspects and physiopathological review. Orthop Traumatol Surg Res 2010;96(8 Suppl):S53–8. doi:10.1016/j.otsr.2010.09.005
      OpenUrlCrossRefPubMed
    65. ↵
      1. Aprato A,
      2. Masse A,
      3. Faletti C, et al
      . Magnetic resonance arthrography for femoroacetabular impingement surgery: is it reliable? J Orthop Traumatol 2013;14:201–6. doi:10.1007/s10195-013-0227-1
      OpenUrlCrossRefPubMed
    66. ↵
      1. Barton C,
      2. Salineros MJ,
      3. Rakhra KS, et al
      . Validity of the alpha angle measurement on plain radiographs in the evaluation of cam-type femoroacetabular impingement. Clin Orthop Relat Res 2011;469:464–9. doi:10.1007/s11999-010-1624-x
      OpenUrlCrossRefPubMedWeb of Science
    67. ↵
      1. Domayer SE,
      2. Ziebarth K,
      3. Chan J, et al
      . Femoroacetabular cam-type impingement: diagnostic sensitivity and specificity of radiographic views compared to radial MRI. Eur J Radiol 2011;80:805–10. doi:10.1016/j.ejrad.2010.10.016
      OpenUrlCrossRefPubMed
    68. ↵
      1. Keeney JA,
      2. Peelle MW,
      3. Jackson J
      , et al. Magnetic resonance arthrography versus arthroscopy in the evaluation of articular hip pathology. Clin Orthop Relat Res 2004;163–9. doi:10.1097/01.blo.0000150125.34906.7d
    69. ↵
      1. Laude F,
      2. Sariali E,
      3. Nogier A
      . Femoroacetabular impingement treatment using arthroscopy and anterior approach. Clin Orthop Relat Res 2009;467:747–52. doi:10.1007/s11999-008-0656-y
      OpenUrlCrossRefPubMedWeb of Science
    70. ↵
      1. Myrick KM,
      2. Nissen CW
      . THIRD test: diagnosing hip labral tears with a new physical examination technique. J Nurse Pract 2013;9:501–5. doi:10.1016/j.nurpra.2013.06.008
      OpenUrlCrossRef
    71. ↵
      1. Peters CL,
      2. Schabel K,
      3. Anderson L, et al
      . Open treatment of femoroacetabular impingement is associated with clinical improvement and low complication rate at short-term followup. Clin Orthop Relat Res 2010;468:504–10. doi:10.1007/s11999-009-1152-8
      OpenUrlCrossRefPubMedWeb of Science
    72. ↵
      1. Sink EL,
      2. Gralla J,
      3. Ryba A, et al
      . Clinical presentation of femoroacetabular impingement in adolescents. J Pediatr Orthop 2008;28:806–11. doi:10.1097/BPO.0b013e31818e194f
      OpenUrlCrossRefPubMed
    73. ↵
      1. Wang WG,
      2. Yue DB,
      3. Zhang NF, et al
      . Clinical diagnosis and arthroscopic treatment of acetabular labral tears. Orthop Surg 2011;3:28–34. doi:10.1111/j.1757-7861.2010.00121.x
      OpenUrlCrossRefPubMed
    74. ↵
      1. Chan YS,
      2. Lien LC,
      3. Hsu HL, et al
      . Evaluating hip labral tears using magnetic resonance arthrography: a prospective study comparing hip arthroscopy and magnetic resonance arthrography diagnosis. Arthroscopy 2005;21:1250. doi:10.1016/j.arthro.2005.07.007
      OpenUrlPubMed
    75. ↵
      1. Hananouchi T,
      2. Yasui Y,
      3. Yamamoto K, et al
      . Anterior impingement test for labral lesions has high positive predictive value. Clin Orthop Relat Res 2012;470:3524–9. doi:10.1007/s11999-012-2450-0
      OpenUrlCrossRefPubMed
    76. ↵
      1. Leunig M,
      2. Werlen S,
      3. Ungersbock A, et al
      . Evaluation of the acetabular labrum by MR arthrography. J Bone Joint Surg Br 1997;79:230–4. doi:10.1302/0301-620X.79B2.7288
      OpenUrlCrossRefPubMed
    77. ↵
      1. Martin RL,
      2. Irrgang JJ,
      3. Sekiya JK
      . The diagnostic accuracy of a clinical examination in determining intra-articular hip pain for potential hip arthroscopy candidates. Arthroscopy 2008;24:1013–18. doi:10.1016/j.arthro.2008.04.075
      OpenUrlCrossRefPubMedWeb of Science
    78. ↵
      1. Maslowski E,
      2. Sullivan W,
      3. Forster Harwood J, et al
      . The diagnostic validity of hip provocation maneuvers to detect intra-articular hip pathology. PM R 2010;2:174–81. doi:10.1016/j.pmrj.2010.01.014
      OpenUrlCrossRefPubMed
    79. ↵
      1. Troelsen A,
      2. Mechlenburg I,
      3. Gelineck J, et al
      . What is the role of clinical tests and ultrasound in acetabular labral tear diagnostics? Acta Orthop 2009;80:314–18. doi:10.3109/17453670902988402
      OpenUrlCrossRefPubMedWeb of Science
    80. ↵
      1. Ayeni O,
      2. Chu R,
      3. Hetaimish B, et al
      . A painful squat test provides limited diagnostic utility in CAM-type femoroacetabular impingement. Knee Surg Sports Traumatol Arthrosc 2014;22:806–11. doi:10.1007/s00167-013-2668-8
      OpenUrlCrossRefPubMed
    81. ↵
      1. Beaule PE,
      2. Zaragoza E,
      3. Motamedi K, et al
      . Three-dimensional computed tomography of the hip in the assessment of femoroacetabular impingement. J Orthop Res 2005;23:1286–92. doi:10.1016/j.orthres.2005.03.011.1100230608
      OpenUrlCrossRefPubMedWeb of Science
    82. ↵
      1. Guyatt G,
      2. Rennie D,
      3. Meade MO, et al
      . Users’ guides to the medical literature: a manual for evidence-based clinical practice. 2nd edn. New York, NY: McGraw-Hill Education, 2008.
    83. ↵
      1. McGuire CM,
      2. MacMahon P,
      3. Byrne DP, et al
      . Diagnostic accuracy of magnetic resonance imaging and magnetic resonance arthrography of the hip is dependent on specialist training of the radiologist. Skeletal Radiol 2012;41:659–65. doi:10.1007/s00256-011-1266-4
      OpenUrlCrossRefPubMedWeb of Science
    84. ↵
      1. Llopis E,
      2. Fernandez E,
      3. Cerezal L
      . MR and CT arthrography of the hip. Semin Musculoskelet Radiol 2012;16:42–56. doi:10.1055/s-0032-1304300
      OpenUrlCrossRefPubMed
    85. ↵
      1. Reiman MP,
      2. Goode AP,
      3. Hegedus EJ, et al
      . Diagnostic accuracy of clinical tests of the hip: a systematic review with meta-analysis. Br J Sports Med 2013;47:893–902. doi:10.1136/bjsports-2012-091035
      OpenUrlAbstract/FREE Full Text
      1. Smith TO,
      2. Hilton G,
      3. Toms AP, et al
      . The diagnostic accuracy of acetabular labral tears using magnetic resonance imaging and magnetic resonance arthrography: a meta-analysis. Eur Radiol 2011;21:863–74. doi:10.1007/s00330-010-1956-7
      OpenUrlCrossRefPubMed

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    Footnotes

    • Contributors MPR developed the idea of manuscript. All the authors contributed in writing, editing and approval of final manuscript.

    • Competing interests None.

    • Provenance and peer review Not commissioned; externally peer reviewed.