Acute Quadriceps Muscle Strains MRI features and prognosis

1. Acute Quadriceps Muscle StrainsMRI features and prognosis Dr Tom Cross MBBS, FACSP, DCH The Stadium Orthopaedic and Sports Medicine Centre

2. Acute Quadriceps Muscle Strains:MRI features and prognosis Dr T Cross Dr N Gibbs Mr M Cameron Dr M Houang AJSM, April 2004

3. Introduction • Literature review • Methods • Results and Discussion • Conclusions • Questions??

4. Clinical Scenarioe.g.. Anterior thigh pain 7 days before World Cup FinalCan he play??

5. 1. Introduction

6. Objective To describe the MRI findings of a series of acute quadriceps muscle strains

7. Objective To assess any relationship between the MRIfindings and the time taken to return to sport

8. Setting • Sydney Swans Football Club • 1 of 16 clubs in the National competition

9. Design Prospective study over 3 years (1999-2001): Both in-season and pre-season periods

10. Patients 40professional footballers Consent from Club and individual players

11. Australian Rules Football “Athletes at risk” • Repetitive sprinting efforts • Repetitive kicking • Repetitive jumping & landing • Game time approximately 100 minutes

12. Australian Rules Football Ideal sport ( “outdoor laboratory”) to study muscle strain injury

13. Australian Rules Football Hamstring strain is the most significant injury in ARF (Quadriceps strain in top 10)

14. Motivation for research • To better understand/diagnose quadriceps muscle strains • To better manage/rehabilitate quadriceps muscle strains

15. Motivation for research • To make an EARLY ACCURATE PROGNOSIS (i.e. we were unable to clinically differentiate benign from serious quadriceps strains)

16. 2. Literature Review

17. Literature review Pomeranz (1993) • Retrospective study of Hamstring strains • n=14 • Prognosis associated with size (cross-sectional area%) of muscle strain injury on MRI scan

18. Literature review No research (i.e. series of cases) on, Clinical behavior MRI findings of acute quadriceps strains

19. Literature review No mention of Vastus quadriceps muscle strains in the literature

20. Literature review No research (i.e. series of cases) on “ distal rupture of rectus femoris” Distal rupture of RF

21. Literature review 3 retrospective studies on chronic muscle strain injuries of rectus femoris : all cases were “proximal injuries” • Rask and Lattig (1972) n=5 • Hughes and Hasselman (1995) n=10 • Temple et al (1998) n=7

22. Literature review Chronic “proximal strain injury” of rectus femoris Mean time to presentation = 7 months Tender anterior thigh mass Associated anterior thigh pain, weakness and dysfunction

23. Literature review Chronic “proximal strain injury” of rectus femoris The Dilemma! Research: Basic science studies found that muscle strain injury occurs at/near muscle-tendon junctions Q. Where is this muscle strain injury sited with respect to the known musculotendinous junctions???

24. Literature review • Hughes and Hasselman (1995, AJSM) Rectus femoris- cadaveric dissection

25. Literature review Special anatomy of rectus femoris Left thigh Hughes and Hasselman (1995) Superior acetabulum AIIS

26. Literature review Unipennate structure: proximal 1/3 of RF Central tendon Bipennate structure: Middle and distal 2/3 of RF

27. Literature review Chronic “proximal strain injury” of RF Muscle strain injury about the “intramuscular tendon of the indirect head” (the Central tendon) Central tendon Chronic “bull’s eye lesion” Fibrotic scar New muscle-tendon junctions

28. Chronic “Bulls Eye" lesion Normal Central Tendon

29. Chronic symptomatic “bull’s eye lesions” Macroscopic Microscopic Histology: centrally dense mature fibrous tissue with surrounding oedema, chronic inflammation, hemosiderin deposition, interspersed with normal and degenerating muscle fibres about NEW MUSCLE-TENDON JUNCTIONS

30. Literature review: continued…. Rectus femoris, an “at-risk muscle” • Acts eccentrically • Crosses two joints • High % fast twitch fibres

31. Literature review Vastus muscles • Act eccentrically • Cross only one joint • High % slow twitch fibres • Large bulk of synergistic muscles

32. 3. Methods

33. Methods Inclusion criteria • History • acute or gradual onset of anterior thigh pain while training or playing • Mechanism of injury documented (running, kicking, jumping/landing): if onset of symptoms were acute • Preferred kicking leg was correlated with the side injured • Examination : tenderness over the anterior thigh : other signs elicited but not the subject of this study

34. Methods Exclusion criteria • History of trauma to anterior thigh (Contusion) • Delayed onset of anterior thigh pain (DOMS)

35. Methods MRI within 24-72 hours • T1,T2 with fat suppression, STIR • Axial, coronal planes (both thighs imaged) (Axial T2with fat suppressionmost useful images)

36. Methods Muscle strain injury= high signal on T2 weighted images

37. Methods MRI diagnosis Location (MRI category) • Which quadriceps muscle (s) injured • Location of injury with respect to known musculotendinous junctions

38. Methods MRI diagnosis Size • Cross sectional area % (CSA) • Length (cm)

39. Methods • CSA% estimation (“dot” method)

40. Methods MRI diagnosis: miscellaneous features… • T2 hyper intensity • muscle fibre disruption • Perifascial fluid • Scarring/fibrosis

41. Methods What if more than one muscle injured? (i.e. double injury etc.) • Primary muscle injured= greatest CSA% • Secondary muscle injury= smaller CSA%

42. Results of acute MRI images • 25 acute clinical quadriceps strains were imaged • Authors were not blinded to these MRI’s

43. MRI negative n=3 Central tendon Central tendon

44. High signal on both sides of CT = an acute “bull’s eye” lesion RF-CTn=7

45. RF-CT (coronal) “feather-like” pattern

46. RF-CT High signal on only one side of CT

47. RF-CT High signal on one side of CT

48. No high signal about Central Tendon High signal in periphery RF-peripheral n=8

49. RF-periphery High signal about posterior lamina of RF

50. Anterior lamina of VI High signal in VI Vastus Intermedius n=6