Midportion versus insertional tendinopathy, and for a rupture the gap in cm (resting and in plantarflexion) with the site — the numbers that decide conservative functional treatment versus repair.
Orient first
- Midportion tendinopathy is 2–6 cm above the insertion (watershed); insertional tendinopathy comes with Haglund deformity and bursitis.
- Complete ruptures are usually 2–6 cm above the insertion.
- A plantaris tendon intact beside a ruptured Achilles can mimic continuity.
Acquire the study
- High-frequency linear probe; longitudinal and transverse planes; passive plantarflexion and dorsiflexion.
The manoeuvre
- Transverse plane: AP thickness in mm (normal ~5–6 mm — verify).
- Power Doppler: neovascularity in tendinopathy.
- Rupture: gap length in cm at rest and in plantarflexion; distance from the calcaneal insertion.
- Retrocalcaneal bursa fluid; Haglund bump.
What confirms it
- Tendon discontinuity with a gap that persists in neutral.
What licenses you to exclude it
- Normal thickness and fibrillar pattern exclude significant tendinopathy.
The classic misread
- The intact plantaris tendon mistaken for residual Achilles fibres.