Avascular Necrosis Of The Sesamoids

HISTORY:(5/1/24) Patient is a 28 y/o female runner with 2 month history of right foot pain, no specific injury with insidious onset of the pain that was progressively worsening. The pain was located on the plantar aspect of the foot at the base of the first digit/ball of their foot. Denies pain with walking but had pain with running, especially with long distances. She was training for The Chicago marathon which included running/walking 10 miles daily. Pain is also worse with push off in her running stride. She denied any other major symptoms. PHYSICAL EXAMINATION: Right foot exam: Non-antalgic gait, no appreciable pes planus, no skin changes, bruising, swelling. There was Mild/moderate tenderness to palpation of the plantar surface at the 1st MTP and over sesamoid bones. Full range of motion with ankle and digit movement and also had 5/5 strength in all plane movements at the ankle. Sensation was intact and symmetric. DIFFERENTIAL DIAGNOSIS: Differential diagnosis included Sesamoiditis, bone contusion, stress fracture, sesamoid fracture, forefoot fat pad atrophy, early onset osteoarthritis, soft tissue disorder related to overuse and pressure, FHL tendonitis, or Plantar plate injury. TEST AND RESULTS: X-ray Right foot (5/1/24): No acute fracture or malalignment. Sesamoid bone is multipartite, a normal anatomic variant. MRI Right foot without contrast (5/17/24): Low signal intensity and fragmentation of the lateral hallux sesamoid that is suggestive of chronic avascular necrosis. Also mild avascular necrosis of the medial hallux sesamoid. FINAL WORKING DIAGNOSIS: Avascular necrosis of the hallux sesamoid bones TREATMENT AND OUTCOMES: It was decided to work on load management and get an orthotic with sesamoid cutout. She would continue to weight bear with supportive shoes and avoid barefoot walking or running. She also was instructed to maintain a home exercise program focused primarily on calf stretching and strengthening. All of these interventions were sufficient in allowing her to run pain free and avoid necrosed sesamoid removal. She was able to run the marathon with minimal to no pain!