20-year-old patient with right ankle and/or Achilles region symptoms. Ultrasound examination was performed of the Achilles tendon, flexor hallucis longus, tibialis posterior, flexor digitorum longus, peroneus longus and brevis, talocrural joint, retrocalcaneal bursa, medial and lateral ankle ligaments, and syndesmosis.
Ultrasound examination of the right ankle demonstrates mild swelling/hydrops of the talocrural joint, compatible with intra-articular irritation or reactive joint effusion.
The Achilles tendon shows moderate mid-portion tendinopathy. No partial or complete Achilles tendon rupture is present.
At the lateral ankle, the calcaneofibular ligament is markedly thickened. This is compatible with chronic ligamentous overload or previous inversion trauma. The anterior talofibular ligament is moderately thickened, also consistent with chronic lateral ankle ligament pathology.
No ligament rupture is identified. The remaining scanned tendons and structures are not described as abnormal.
Overall, the imaging pattern suggests chronic lateral ankle ligament changes with secondary talocrural joint irritation, in combination with moderate mid-portion Achilles tendinopathy. Altered ankle mechanics or a compensatory gait pattern may contribute to the Achilles tendon overload.
1. Final diagnosis
Findings are consistent with mild talocrural joint hydrops, moderate mid-portion Achilles tendinopathy, and chronic lateral ankle ligament pathology, with marked thickening of the calcaneofibular ligament and moderate thickening of the anterior talofibular ligament. No rupture is present.
2. Differential diagnosis
The differential diagnosis includes chronic lateral ankle ligament overload, previous inversion sprain with residual ligament thickening, chronic ankle instability, anterolateral impingement, reactive talocrural synovitis, osteochondral talar lesion, and mechanically induced joint hydrops. The Achilles tendon changes are most consistent with primary mid-portion tendinopathy, although altered ankle mechanics or compensatory loading may contribute.
3. Teaching points
Ultrasound is useful for assessing superficial ankle ligaments, tendon structure, tendon thickening, Doppler activity, and joint effusion. Chronic thickening of the ATFL and CFL may reflect previous sprain, repetitive overload, or chronic instability, even in the absence of a visible rupture. Mild talocrural hydrops should prompt clinical correlation for instability, impingement, or deeper intra-articular pathology, which may require MRI if symptoms persist.
4. Injury/disease information
Chronic lateral ankle ligament pathology often follows inversion trauma or repetitive mechanical overload. Residual ligament thickening may be associated with recurrent giving way, reduced proprioception, altered loading, and secondary talocrural joint irritation. Mid-portion Achilles tendinopathy is a load-related tendon disorder characterized by tendon thickening and structural degeneration. Management is usually conservative, focusing on progressive tendon loading, load modification, calf strengthening, proprioception, balance training, ankle stability work, and gradual return to activity. MRI may be considered when there is persistent swelling, locking symptoms, deep ankle pain, recurrent sprains, or insufficient recovery despite appropriate conservative care.
Marc is founder of, and trainer at, SonoSkills. SonoSkills is an organization dedicated to MSK ultrasound education. He's also an MSK Sonographer at EchoConsult in Roermond, the Netherlands.
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