Quadriceps tendon rupture
Epidemiology
- Patients over 40 years old
- More common in males
- Most common location – at the insertion of the quadriceps tendon to the patella
Etiology/pathophysiology
- Axial load on a flexed knee – causes rapid contraction of quadriceps muscle, leading to tendon rupture
- E.g. falls, high-impact landing
- Risk factors – renal failure, diabetes, rheumatoid arthritis, hyperparathyroidism, steroid use
Anatomy – extensor mechanism of the knee
- Quadriceps femoris muscles
- Quadriceps tendon
- Patella
- Patellar tendon
- Tibial tubercle
Classification
- Partial – minimal impact on extensor mechanism
- Complete – marked impact on extensor mechanism
Clinical Features
- Pain
- Tenderness at the site of rupture
- Palpable deformity
- Patient unable to extend knee against resistance
Diagnosis
- X-ray – shows patella baja
- MRI – to differentiate between partial and complete tear
Treatment
- Knee immobilisation in brace
- Primary repair with reattachment to patella – if there is loss of extensor mechanism
Patellar tendon rupture
Epidemiology
- More common in males
- Less common than quadriceps tendon rupture
Etiology/pathophysiology
- Tensile overload of the extensor mechanism – most ruptures occur with knee in a flexed position
- 3 patterns of injury
- Avulsion with or without bone from the proximal insertion (most common)
- Midsubstance
- Distal avulsion from tibial tubercle
- Risk factors – SLE, rheumatoid arthritis, renal failure, diabetes mellitus, patellar degeneration, patellar tendinopathy
Clinical features
- Infrapatellar pain and tenderness
- Popping sensation
- Difficulty weight-bearing
- Large haemarthrosis and ecchymosis
- Patient unable to perform active straight leg raise
Diagnosis
- X-ray – patella alta
- Ultrasound
- MRI – to visualise tendon degeneration and associated soft tissue injuries
Treatment
- Immobilisation in full extension – with weight-bearing exercise programme
- For partial tears with intact extensor mechanism
- Primary repair – for complete tears
- Tendon reconstruction – for severely disrupted/degenerated patella tendon
Achilles Tendon rupture
Epidemiology
- More common in men 30-40 years old
- Often misdiagnose as ‘ankle sprain’
Etiology/pathophysiology
- Mechanisms
- Sudden forced plantar flexion
- Violent dorsiflexion in a plantar flexed foot
- Rupture usually occurs 4-6cm above the calcaneal insertion in the hypovascular region
- Risk factors – fluoroquinolones, steroid injections, episodic athletes
- Largest tendon in the body
- Formed by confluence of 3 tendons
- Soleus tendon, medial gastrocnemius tendon and lateral gastrocnemius tendon
- Inserts into the calcaneous
- Produces plantarflexion of the ankle
Clinical features
- Weakness, difficulty walking
- Pain in heel
- Increased passive dorsiflexion
- Calf atrophy – chronic cases
Diagnosis
- Thompson test – lack of plantar flexion when calf is squeezed
- X-ray
- Ultrasound – to distinguish between partial and complete ruptures
- MRI – for chronic ruptures
Treatment
- Bracing/casting
- Open end-to-end Achilles tendon repair – for acute ruptures <6 weeks
- Percutaenous Achilles tendon repair – higher risk of sural nerve damage
- Flexor hallucis longus transfer – for chronic ruptures