Splendid reliability for MRI grading and prognostic parameters in astute hamstring injuries

Loading

  1. B Hamilton1,ii,
  2. R Whiteley3,
  3. E Almusa4,
  4. B Roger4,
  5. C Geertsemaone,
  6. Johannes L Tol1
  1. 1 Department of Sports Medicine, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
  2. 2 High Functioning Sport New Zealand, Auckland, New Zealand
  3. three Department of Rehabilitation, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
  4. 4 Department of Radiology, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
  1. Correspondence to Dr Johannes L Tol, Department of Sports Medicine, Aspetar; Qatar Orthopaedic and Sports Medicine Hospital, Doha PO Box 29222, Qatar; Johannes.tol{at}aspetar.com

Abstruse

Groundwork Categorical grading and other measurable MRI parameters are frequently utilised for predicting the outcome of hamstring injuries. However, the reliability and smallest detectable difference (SDD) accept not been previously evaluated. It therefore remains unclear if the variability in previously reported results reflects reporting variation or actual injury status.

Methods 25 hamstring injuries were scored by ii experienced radiologists using the Peetrons grading and specific prognostic MRI parameters: distance from ischial tuberosity (cm), extent (cranio to caudal, anterior to posterior, medial to lateral; (cm)), maximum cantankerous-exclusive area (%), volume (cm3) of the oedema. The interobserver and intraobserver reliability was calculated along with the SDDs for each calibration variable.

Results There were iii Grade 0 (12%), xi grade 1 (44%), 9 form 2 (36%) and two form 3 (viii%) injuries. Cronbach's α values for grading were 1.00 (inter) and 0.96 (intra), respectively. The intraclass correlation coefficients for the prognostic MRI parameters were between 0.77 and ane.0. The SDDs varied between each parameter.

Conclusions Excellent interobserver and intraobserver reliability was plant for grading and prognostic MRI parameters in astute hamstring injuries. In daily practise and research, we tin can be confident that scoring hamstring injuries past experienced radiologists is reproducible. The documented SDDs let meaningful clinical inferences to exist made when assessing observed and reported changes in MRI status.

  • Hamstring injuries
  • MRI

This is an Open Admission article distributed in accordance with the Artistic Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, accommodate, build upon this work non-commercially, and license their derivative works on different terms, provided the original piece of work is properly cited and the use is non-commercial. Run across: http://creativecommons.org/licenses/by-nc/3.0/

Statistics from Altmetric.com

  • Hamstring injuries
  • MRI

Introduction

Muscle injuries business relationship for up to 30% of all sporting injuries, with the hamstring complex being the most ofttimes injured site.1–4 MRI is considered useful in confirming injury diagnosis, severity and prognosis, with chiselled and continuous scoring systems constituting validated indicators of time to return to a sport.five–ix

A recent cohort study in European football established the clinical relevance of a widely used categorical grading system.x ,11 Notwithstanding, hamstring injuries may be considered a heterogeneous grouping and other researchers take focused on prognostic MRI parameters such every bit intramuscular location and extent of the injury.7 ,ix For case, the location, in particular the continuous distance to the ischial tuberosity, has a fair5 to good6 correlation with time to return to preinjury office. Similarly, measurements of the extent of the injury in 3 planes take shown correlation coefficients betwixt 0.39 and 0.74 (table 1).5–8 With increasing MRI availability, understanding of the clinical relevance of each of these variables continues to evolve.

View this table:

  • View inline

Table ane

Prognostic MRI parameters

Despite the frequent application of these MRI parameters, at that place are no data published regarding the reliability and smallest detectable differences (SDDs) in the MRI interpretation of hamstring muscle injuries. As a result, it remains unclear if the variability in study findings reflects a variability in the reporting or actual MRI condition. The aim of this report was to evaluate the interobserver and intraobserver reliability and certificate SDDs of MRI grading and other prognostic parameters in acute hamstring injuries.

Methods

The investigation formed part of a randomised controlled trial evaluating acute hamstring injuries (ClinicalTrial.gov number NCT01812564). Approving was obtained from the Ideals Committee of Aspetar, Qatar Orthopaedics and Sports Medicine Hospital and informed consent was obtained from all included patients.

Patients were recruited between November 2009 and December 2012 at an orthopaedic and sports medicine hospital in Qatar. For this substudy, 25 patients out of the recruited cohort who met singled-out inclusion criteria (astute onset of posterior thigh pain, MRI performed within 5 days from injury, historic period >18 years and male) were randomly selected. One investigator randomly selected 25 patients past circling the unique anonymised patient study number on a list of all patients.

MRI

The players were positioned supine and examined with a one.five Tesla Siemens Espree. In addition to a phased array curl, two-body matrix coils were strapped over the thigh and centred over the painful area, identified by the athlete and marked past the physician. Centric and coronal proton density with fat saturation along the longitudinal axis of the thigh (TR/TE 3490/27 and a 512×326 matrix for the coronal images and TR/TE 3000/32 and a 512×333 matrix for the axial images) with one signal boilerplate each were obtained. The field of view used on the coronals was 25 cm and 24 cm with the axial images and a 3.5 mm section thickness with no gap.

MRI assessment

Prior to the written report, two radiologists were familiarised with the MRI scoring protocol, in a trial involving 10 patients. Each radiologist scored the MRIs in random gild between May 2012 and January 2013. Radiologist one (EA), who was also involved in other hamstring diagnostic studies, scored 128 MRIs in this period. During this process, MRIs were randomly allocated each week in sets of 3–5 with at least ii months betwixt the beginning and second evaluations of the same MRI. Radiologist ii (BR) scored sets of iii–5 MRIs on a weekly basis in the same manner.

The radiologists, each with more than 9 years of experience in musculoskeletal radiology and blinded to the clinical status of the injury, independently interpreted the MRIs, scoring them co-ordinate to a modified Peetrons classification system;10 ,11 grade 0: no abnormalities; grade I: oedema without architectural distortion; grade II: oedema with architectural distortion; and grade III: consummate tear.

Additional prognostic MRI parameters measured were: craniocaudal, transverse and anteroposterior dimensions (cm) of identified oedema, and distance from the most proximal site of oedema to the ischial tuberosity (cm). Nosotros subsequently calculated the volume (cm3) of musculus involved and the maximum involved cross-exclusive expanse every bit a percentage of the full muscle cross-exclusive expanse in the transversal plane.

When more than one muscle was involved, the muscle with the nigh extensive oedema or tear was scored.

Information assay

Interobserver and intraobserver reliability was calculated with a one-style random model. For the categorical variable of overall grade, a scoring system (with choices of 0, 1, 2 or three) per observer per hamstring injury was recorded.10 ,eleven The interobserver reliability for these measures was estimated using Cronbach's α. For the parametric values, the intraclass correlation coefficient (ICC(2,one)) was calculated to approximate reliability. The inter-rater reliability is considered excellent if the ICC is >0.75, off-white to adept if 0.4<ICC<0.75 and poor if ICC is <0.4.12 The SDD was calculated from the inter-rater reliability assay.

Results

A full of 316 patients met the inclusion criteria, and all selected 25 MRIs were included in the analysis. Patient characteristics are presented in table 2. There were 3 Course 0 (12%), xi Class 1 (44%; biceps long caput (BLH) injuries), 9 grade 2 (36%; half dozen BLH ii semitendinosis (ST) and i semimembranosis (SB) injury) and 2 grade 3 (8%) injuries. The hateful values of the prognostic MRI parameters, reliability and SDD data are presented in table iii.

View this table:

  • View inline

Table 2

Patient characteristics (N=25)

View this table:

  • View inline

Table iii

Mean values (SD), interobserver and intraobserver reliability, 95% CI and SDD of prognostic parameters and grading11 in 25 acute hamstring injuries

Discussion

In this study, the interobserver and intraobserver reliability for MRI grading and prognostic parameters in acute hamstring injuries was excellent. When experienced radiologists report MRI data on hamstring strain injuries, we can be confident that the detailed assessment of MRI for injuries in these muscles volition be a reproducible finding. This is an important and clinically relevant finding when one considers the increased employ of MRIs in the diagnosis and prognosis of hamstring injuries, which has non been reported previously.

Values for SDDs are critical for our understanding of comparative prognosis between patients and continuous evaluation of private patients. Despite this, the SDDs for hamstring musculus evaluation with MRI have not been reported previously. The SDD for oedema measurement of approximately one.0–1.5 cm for three planes highlights that very modest differences may accurately reflect true variation in oedema in these planes. The SDDs presented here may be used both when comparing between different patients (for the assessment of relative prognosis), and for serial imaging of the same patient to clarify if the reported changes in MRI parameters (eg, in the length of tear, extent of oedema) are potentially due to measurement error (changes less than the SDD) or not (changes greater than the SDD).

Chiselled scales for grading musculus injuries are pragmatic and pop with clinicians and patients.x ,11 ,13 This is despite the seemingly arbitrary depiction of form descriptions. The SDD data illustrated here may provide guidance for the development of sensible cut-off points for any planned subgroup analyses.

Increasingly, studies are utilising MRIs for assessing hamstring muscle injury, its location, extent and relationship with prognosis.6 ,x However, the ultimate significance of many of the imaging findings described remains to be determined and, as such, the importance of a clear history and test must not be lost.thirteen ,xiv

While these data suggest good levels of reliability, it is important to note that this was between two experienced musculoskeletal radiologists, afterward a familiarisation trial involving 10 patients, using 1.5 Tesla field strength and high-resolution MRI (3.5 mm slices). One should be cautious almost extrapolating these information to less experienced radiologists, who may non have such an opportunity for familiarisation and appraisal. In any future inquiry, although our reported ICC was excellent, this may not translate to other studies and use of this reliability finding should be considered essential in any research or assay of radiological MRI grades sub-groups. However, future research may utilise this reliability and the SDD data to clarify the nature of the relations between MRI parameters and clinical outcomes.

Similarly, future technical developments may deem i.5 Tesla MRI to have inadequate sensitivity for specific variables of interest in muscle injury diagnosis, as 3.0 Tesla MRI already appears to exist clinically more sensitive. However, in all recently published high-level studies, ane.5 Tesla MRI was used to allocate the hamstring injury (Ekstrand et al 2, Asklling et al half dozen and Silder et alfifteen). Time to come research may use reliability studies on 3.0 Tesla MRI.

In decision, this is the start study to evaluate the interobserver reliability and SDD in assessing the MRI grading, location and extent of hamstring injuries. An excellent interobserver and intraobserver reliability was found. The SDDs presented allow clinically meaningful inferences to be fabricated when comparing within-subjects and between-subjects with hamstring muscle injuries.

References

  1. ↵
  2. ↵
  3. ↵
  4. ↵
  5. ↵
  6. ↵
  7. ↵
  8. ↵
  9. ↵
  10. ↵
  11. ↵
  12. ↵
  13. ↵
  14. ↵
  15. ↵

Request Permissions

If you wish to reuse any or all of this article please apply the link below which will accept you to the Copyright Clearance Center'southward RightsLink service. You will exist able to get a quick price and instant permission to reuse the content in many different ways.

Copyright data:

Published by the BMJ Publishing Group Limited. For permission to utilize (where not already granted nether a licence) please go to http://group.bmj.com/grouping/rights-licensing/permissions This is an Open up Access article distributed in accord with the Artistic Commons Attribution Not Commercial (CC BY-NC three.0) license, which permits others to distribute, remix, adapt, build upon this piece of work non-commercially, and license their derivative works on dissimilar terms, provided the original piece of work is properly cited and the utilize is non-commercial. Run across: http://creativecommons.org/licenses/by-nc/three.0/