- Third most common tendon rupture
- Most common in 3rd to 5th decades
- Age related changes that facilitate Achilles rupture :
- Decreased perfusion
- Decrease in collagen cross linking and elasticity
- Increased stiffness
- Rupture occurs in a relatively hypovascular area of the tendon, 2 - 6 cm above its insertion into the calcaneus
- Repetitive microtrauma causes an inflammatory reparative process that in presence of decreased vascularity is unable to keep up with the stress
- Usual mechanisms :
- Sudden push off while knee is extended
- Forceful ankle dorsiflexion against a contracted heel cord
- Fall from a height on plantar flexed forefoot
Clinically
- Sharp tearing pain behind ankle following activity
- Patients often describes incident as if someone kicked him in ankle or has been shot
- Palpable defect of Achilles
- Inability to 'toe-walk'
- Simmond's test is diagnostic (also called Thompson's test)
- Active plantar flexion is less reliable, for it can be performed by other tendons that pass behind medial malleolus
Investigation
- Ultrasound and MRI demonstrate tear in doubtful cases
- MRI differentiates partial tears from complete tears, tendinosis or inflammation
Treatment
Acute
Nonoperative
- Best results obtained if :
- Under 48 hours
- Low demand patient
- No palpable tendon gap in 20° plantar flexion
- Immobilise in plantar flexion cast for 8-12 weeks
- Gradually decrease plantar flexion in 2-week intervals; reaching neutral at 8 weeks
- Maintain cast for another 4 weeks in neutral
- Use heel lift for 2-3 months after cast removal
- Higher re-rupture rate and lower power is reported in non operative management
Operative
- Most proper for young, active patients
- Posteromedial skin incision
- Allows access to plantaris to augment repair
- Suture (Kessler/Bunnell with peripheral suture)
- Repair paratenon separately
- Post op management is similar to no operative therapy
Late repair of chronic rupture (>4 weeks)
Old, low demand or medically unfit patients
- Rocker bottom shoe
- Hinged ankle brace with dorsiflexion stop
Young active patients
- Difficult to approximate ends
- Common methods used to close the gap are :
- V-Y plasty (Abraham)
- Turned down flap of proximal tendon (Lindholm/Bisworth)
- Proximal release of muscle attachment
- Can supplement repair with :
- Plantaris
- Fascia lata
- FDL
- FHL
- Peroneus brevis
Complications
- Skin slough
- Re-rupture
- Reduced power
- Adhesions
- Stiffness of ankle with reduced dorsiflexion
Prognosis
- Earlier return to activity in operative treatment
- Re-rupture rate:
- Operative 2-7%
- Non-operative 8-35%
