LAMENESS DIAGNOSES: WHY SO MANY TOOLS?

1. LAMENESS DIAGNOSES: WHY SO MANY TOOLS? ANTONIO M. CRUZ DVM, MVM, MSc, DrMedVet, Dipl ACVS, Dipl ECVS Board Certified Specialist in Large Animal Surgery American/European College of Veterinary Surgeons Paton and Martin Veterinary Services Aldergrove, BC www.pmvetservices.com

2. DISCLAIMER THE MATERIALS CONTAINED IN THIS PRESENTATION ARE PROTECTED BY COPYWRIGHT LAWS. PLEASE DO NOT DOWNLOAD ANY OF IT FOR OTHER PURPOSES THAN PERSONAL USE.

3. WHO AM I?

9. My work as a University Prof.

10. Lameness Investigation • Methodic • Not rushed • Set realistic expectations • May take several days

11. Our Most Important Tool

12. Process • Adequate history of problem: Listen!! • Ask relevant questions • Observe!! • From a distance • Horse posture\attitude • Conformation • Muscle development

13. EXQUISITE KNOWLEDGE OF ANATOMY AND FUNCTION

14. CONFORMATION

15. CONFORMATION

16. FOOT / DIGIT

17. Hunter’s bump

18. PALPATION BACK LEGS HEAD AND NECK MOUTH HOOF TESTERS FOR SORENESS, SWELLINGS, HEAT…

20. PHYSICAL EXAM • Range of motion (ROM) • Regional • Active range of motion: voluntary Lateral, flexion • Passive range of motion: under sedation or GA • Active Assisted ROM: Stimulate to move Wither elevation, trunk elevation, spinal reflexes • Soft Tissue palpation: Sensitivity • Skin, fascia, muscle

21. DYNAMIC EXAM

22. Horse’s gait

23. Appreciate movement

24. NEUROLOGICAL OR LAME

25. FLEXION (STRESS) TESTS

26. MYTHS There is a characteristic gait for each lameness : False Horses always compensate the same way: False Nerve blocks should only be done after imaging: False

27. FACTS There is no magic wand You ALWAYS need to eliminate the lameness to identify its origin : by nerve or joint blocks You CANNOT ALWAYS identify the origin of a lameness Horses compensate in many different ways

28. FACTS Lameness evaluation is an art that requires accurate work and the examiner’s brain CANNOT be substituted by computers or imaging. Any diagnostic tool is only as good as the person using it. Indiscriminate use of diagnostic imaging tools will cloud the picture and confuse you, besides costing you unnecessary expense. A horse is not your car!

29. NERVE/JOINT BLOCKSBLOCK = ANAESTHESIA They are the ONLY way to connect the clinical and imaging findings to the REAL problem so it can be identified By abolishing the pain we are confirming the origin They isolate a segment or joint They are not 100 % - Need interpretation

30. A note about blocking the foot Today the diagnosis of heel pain remains elusive. However with the advent of MRI we are learning the group of lesions that in the past may have been considered “navicular disease or syndrome”. It is important to recognize therefore that not all “heel pain” means navicular disease and that only after an appropriate and extensive diagnostic work-up which may require extensive blocking and diagnostic imaging such as MRI the diagnosis of navicular disease can be made.

31. “HEEL PAIN” SYNDROME • Defined as a lameness that responds to a palmar digital nerve block. • It may include diagnosis such as: • Navicular disease/syndrome • DJD of coffin joint • Navicular bursitis • DDF tendonitis • Coffin join collateral ligament desmitis • Sole bruises • Sheared heels

32. Summary…

33. EQUINE FOOTDIAGNOSTIC NERVE BLOCKS Abaxial sesamoid block Palmar Digital n. block

34. Palmar digital (PD) nerve block • VOLUME • 1.5 mls • MEANING • 5 minutes • 15 minutes • 30 minutes

35. Abaxial sesamoid block

36. Navicular Bone • Deep digital flexor tendon runs over it • Insertion of ligaments • Forms part of coffin joint • Covered by hyaline cartilage on dorsal (coffin) side and by fibrocartilage on palmar (Nav. Bursa) side Deep Digital Flexor Tendon Navicular Bone

37. Coffin Joint Made up of coffin bone, pastern bone and navicular bone Minimal motion: forward and backward Second phalanx = pastern Coffin Bone Navicular Bone

38. EQUINE FOOTDIAGNOSTIC SYNOVIAL ANALGESIA • COFFIN JOINT • Joint, navicular bone, distal aspect of DDF, impar ligament, sole, palmar processes of the coffin bone, NAVICULAR BURSA

39. COFFIN JOINT ANAESTHESIA • PREVIOUS RESULTS • 20 % of horses with navicular pain did not response to coffin joint anest. • 80 % of horses without radiologic abnormalities of NB but with positive response to coffin joint were positive on scintigrafia of the podotrochlea • 70 % of horse with NB abnormalities on MRI had a positive response to coffin joint anaesthesia. • 90 % of horses with lesions on DDF detected by MRI responded to coffin joint anaesthesia within 5 minutes. • 17 % of horses with lesions on DDF detected by MRI responded to Nbursa block • 90 % of horses with positive response to coffin joint anaest and N Bursa had positive scintigrafic findings on the podotrochlea.

40. Navicular Bursa Block • More specific than coffin joint • Evaluate at 5, 15, 30 minutes • Positive response indicates podotrochlea pathology • May desensitize DDF insertion and heel • Results (59 horses; Dyson y col.) • 60 % of horses had radiographic abnormalities and all of them responded to N bursa block • 70 % of horses with abnormalities of the NB found on MRI showed a positive response to blocking of the bursa. • 12 % without response to coffin joint or bursa had normal scintigraphic findings. • Lack of response to coffin joint anesthesia and bursa eliminates almost entirely the diagnosis of navicular disease.

41. WHAT’S NEXT? AFTER a limited anatomical region has been identified, imaging should proceed

42. IMAGING TOOLS • ANATOMICAL • Radiographs (for bone / joints) • Ultrasound (for soft tissue, tendons, ligaments…) • MRI (for hard and soft tissues) • ARTHROSCOPY • FUNCTIONAL • Scintigraphy = bone scan • Thermography • MRI

43. X-rays (joints)

44. X-rays (Cysts)

45. X-rays (“chips”)

46. Why X-rays are the gold standard

47. Contrast Enhancement

48. ULTRASOUND TENDON SHEATH

49. ULTRASOUND LIGAMENT