The correct answer is choice 2, painful crepitus of the tendon with passive motion at the great toe. Figure A shows an axial cut of an MRI with fluid centered around the flexor hallicus longus (FHL) tendon, consistent with a diagnosis of tendinitis. Passive motion of the great toe causes movement of the inflamed FHL tendon at the ankle joint and resulting pain.
Tendinitis of the FHL is common a common cause of medial-sided ankle pain in dancers. Physical exam findings include painful crepitus with passive motion of the great toe, posteromedial tenderness, and triggering of the great toe. Treatment is initially conservative with ice, NSAIDs and activity modification. Steroid injections are contraindicated given the close proximity of the posterior tibial nerve. If conservative treatment fails, release of the FHL from its fibro-osseous tunnel has shown good results.
Hamilton et al. in JBJS present level 3 evidence where they operated on 41 patients with a combination of FHL tendinitis and posterior impingement. For those with FHL tendinitis, release of the fibro-osseous was performed. 30 out of the 41 patients were described as having a good or excellent result.
OKU gives a brief overview of FHL tendinitis. They conclude that if non-operative measures fail (activity modification, PT, NSAIDs), release of the fibro-osseous tunnel should be considered.
Illustration A shows the axial MRI scan of the ankle with anatomic labels.
Incorrect answer choices:
Answer 1: Pain with percussion of the posterior tibial nerve is consistent with tarsal tunnel.
Answer 3: Posterior ankle pain with forced passive plantar flexion is characteristic of posterior impingement.
Answer 4: Medial ankle pain with resisted inversion is consistent with a diagnosis of posterior tibial tendinitis.
Answer 5: Foot drop with weakness of dorsiflexion is most consistent with acute rupture of the tibialis anterior tendon.
Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 249-261
Hamilton WG, Geppert MJ, Thompson FM: Pain in the posterior aspect of the ankle in dancers: Differential diagnosis and operative treatment. J Bone Joint Surg Am 1996;78:1491-1500
PMID:8876576 (Link to Abstract)