5b (Ankle) - Answer: 68-year-old male is being evaluated for peroneal rupture in left ankle

HISTORY: 

This 68-year-old male is being evaluated for peroneal rupture in left ankle.


(QUIZ ANSWER) ABNORMAL TENDON IN THIS CASE:

Tendon of tibialis posterior.


Using the diagnostic web viewer, we have provided images that assist in telling our clinical story. Areas of significance are indicated below.


FINDINGS: 

Hindfoot valgus and pes planus deformity are present.

Small subchondral erosions noted in lateral margin and center of talar dome, suggestive of high-grade chondromalacia at these locations. Moderate degenerative changes of intertarsal and tarsometatarsal joints noted. Small ossicles noted above anterior calcaneal process in keeping with prior injury. Dorsal spurring of talonavicular joint is seen without evidence of tarsal coalition.

Os trigonum with synchondrosis with talus and minimal osteoedema at the talar side. No significant Intraosseous or surrounding inflammatory changes to suggest impingement syndrome.

Moderate subcortical osteoedema with intraosseous cystic changes noted in lateral aspect of inferior talus and superior calcaneus. Findings are suggestive of lateral hindfoot impingement.

Medial and lateral collateral ligaments, particularly spring ligament are intact.

Interosseous talocalcaneal ligament, cervical ligament and extensor retinaculum are intact. A ganglion pseudocyst measuring 2 cm x 1 cm is seen at the dorsal lateral aspect of the sinus tarsi.

Peroneus longus and brevis tendons and tendon sheaths are unremarkable. There is mild to moderate hypertrophic tendinopathy of plantar portion of posterior tibialis however no definite tear seen. Anterior tendon group is unremarkable.

Achilles tendon is unremarkable.

Small spurring is seen at the plantar aspect of the calcaneus. No active plantar fasciitis. Severe fatty infiltration and volumetric atrophy of the abductor digiti minimi is noted and may represent Baxter's neuropathy.

Varicose veins noted in medial tarsal tunnel.


CONCLUSION:

1. Hindfoot valgus and pes planus deformity. Lateral hindfoot impingement.

2. Moderate hypertrophic tendinopathy of plantar segment of posterior tibialis with no tear.

3. Severe fatty infiltration and volumetric atrophy of the abductor digiti minimi.

4. Mild sinus tarsi inflammatory changes with a ganglion cyst at the lateral aspect.

5. Scattered degenerative articular changes as described above.


ADDITIONAL EDUCATIONAL NOTES:

Q1 - Which segment of this tendon (of the tibialis posterior) is most commonly involved in acute sport injury or chronic injury?

A1 - In acute sport injuries, with young athletes, rarely a tendon rupture happens at the navicular attachment. However, they mostly present with tenosynovitis. With chronic injury, the retromalleolar segment is most commonly involved.


Q2 - What complications are associated with insufficiency of this tendon (of the tibialis posterior)?

A2 - It can result in pes planus, plantar flexion of talus with hind foot valgus, varus deformity of forefoot and sinus tarsi syndrome, and in late stages, tibotalar valgus deformity.


Q3 - What are the important stabilizers of the longitudinal arch of the foot? 

A3 - The most important stabilizer is PTT (dynamic stabilizer), followed by spring ligament and to some degree interosseous talocalcaneal ligament, cervical ligament and extensor retinaculum within the sinus tarsi. Hence, failure of PTT will result in transmission of force to other arch stabilizers. In long term, it causes spring ligament sprain and sinus tarsi syndrome, and eventually lateral hind foot impingement.


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