Interactive Case Tutorial Case 04 Large Animal Bone

Instructions Review the history and signalment for the client Evaluate the radiographs provided Explore the interactive images and compare the answers given with your own interpretations. When you’ve clicked on the image, click the same spot again to make the label disappear. Answer the questions regarding a diagnosis and recommendations Review the radiologist’s findings

Case Presentation Signalment: 10 year old Appendix mare History: on and off right pelvic limb lameness since purchased several months ago for the purposes of hunter/jumper use; grade 3/5 right pelvic limb lameness; positive to hoof testers; moderate positive to distal limb flexion Study: distal right pelvic limb Technique note: a skyline view of the navicular bone is difficult to obtain in a pelvic limb

Distal right pelvic limb Small osteophyte Normal navicular Faint lucent line on distal phalanx R HIND

Distal right pelvic limb Irregular lucent line at lateral plantar process Sclerosis Solar margin resorption Line extends into distal interphalangeal joint Normal navicular bone

Distal right pelvic limb Enthesopathy at origin collateral ligament Normal navicular Normal medial plantar process Line extends into distal interphalangeal joint Irregular lucent line at lateral plantar process Sclerosis Solar margin resorption

Conclusions Provide a diagnosis based on your findings. Feedback Submit Chronic, likely type II (intra-articular), fracture involving the lateral plantar process of the distal phalanx of the right pelvic limb Healing is suspected as at the dorsal surface the lucent line is not as visible Feedback Continue

Recommendations Provide your recommendation for this client. Feedback Egg bar shoe with 4 clips to use the hoof wall to provide equal support of the foot and fractured distal phalanx The shoe should be reset every 6-8 weeks for at least the next 4 months Complete stall rest for at least the next 3 months Recheck lameness evaluation and radiographic evaluation in 3 months Feedback Continue Submit

Findings An irregular lucent line traverses the lateral plantar process extending into the distal interphalangeal joint The bone surrounding the lucent line is sclerotic and the margins are poorly defined Resorption is present at the solar margin of the lateral quarter/heel of the distal phalanx

Follow-up At 3 month recheck, lameness had mildly improved. On radiographs, the fracture line had healed approximately 60%. Continued stall rest for an additional 6-8 weeks was recommended, followed by 5-10 minutes of hand walking twice daily with an increase of time by 5 minutes every two weeks after that Note that fractures of the distal phalanx may heal by fibrosis; thus, a lucent line may always be present to a variable degree

The End