Tendon Rupture

Tendon rupture is partial or complete structural failure of a tendon, producing loss of normal force transmission from muscle to bone.

Rupture may be:

• Acute traumatic
• Degenerative
• Spontaneous through diseased tendon
• Open tendon laceration

Clinically, the most useful distinctions are:

Partial versus complete

A partial rupture retains some continuity and function.

A complete rupture produces full structural discontinuity.

Acute versus chronic

Acute tears have relatively mobile tendon ends and better potential for direct primary repair.

Chronic neglected tears progressively develop:

• Retraction
• Adhesion
• Muscle atrophy
• Fatty degeneration
• Tendon gap

and may require reconstruction rather than direct repair.

Risk factors for spontaneous or low energy rupture include:

• Increasing age
• Chronic tendinopathy
• Diabetes
• Renal disease
• Hyperparathyroidism
• Systemic inflammatory disease
• Fluoroquinolone exposure
• Systemic or local corticosteroid exposure
• Previous tendon injury

Patients often describe:

• Sudden snap or pop
• Acute pain
• Immediate weakness
• Loss of a previously normal movement
• Palpable tendon defect

The examination must assess function, not merely tenderness.

Examples:

Quadriceps tendon

Loss of active knee extension and inability to perform straight leg raise.

Patellar tendon

Same extensor mechanism failure, usually with a high riding patella.

Distal biceps

Loss of flexion strength and particularly supination strength.

Triceps

Weak or absent resisted elbow extension.

Achilles

Loss of plantar flexion power with positive Thompson test.

Partial ruptures can preserve enough function to make the diagnosis less obvious.

Diagnosis is often clinical.

Ultrasound: rapidly determines tendon continuity, dynamic movement and approximate gap.

MRI: useful when:

• Partial versus complete injury is uncertain
• Chronic tear is suspected
• Retraction must be measured
• Muscle quality affects reconstruction
• Associated soft tissue injury is important

Plain radiographs may reveal:

• Avulsion fragment
• Abnormal patellar height
• Associated fracture

Management depends heavily on the tendon involved.

Partial rupture

A partial tear with preserved function can often be treated with:

• Relative rest
• Short protective immobilisation where necessary
• Progressive physiotherapy
• Correction of precipitating factors

Progress loading according to pain and function.

Failure to regain strength or progression to complete rupture requires reassessment.

Complete rupture

A complete rupture causing major functional loss usually requires either:

• Structured functional rehabilitation

or

• Surgical repair

depending on the tendon.

Not all complete tendon ruptures require surgery. Acute Achilles rupture is the important example where modern functional nonoperative treatment can produce results close to operative repair in appropriately selected patients.

Extensor mechanism rupture

Complete quadriceps or patellar tendon rupture with loss of active knee extension generally requires early surgical repair.

Repair is easier during the first several weeks before:

• Tendon retraction
• Scar formation
• Patellar migration
• Quadriceps shortening

Acutely, use strong nonabsorbable or high strength sutures with:

• Transosseous tunnels

or

• Suture anchors

according to tear location.

Chronic extensor mechanism disruption may require:

• V Y advancement
• Tendon autograft
• Allograft
• Synthetic augmentation

Distal biceps rupture

A complete distal biceps rupture in an active patient generally benefits from repair because nonoperative treatment leaves substantial loss of supination strength.

Repair is ideally performed during the early period before major tendon retraction and scarring.

Older low demand patients may accept nonoperative treatment.

Open tendon injury

Open laceration requires:

• Wound assessment
• Irrigation and debridement when contaminated
• Neurovascular examination
• Primary tendon repair when tissue is suitable

A contaminated open tendon injury should not be closed around devitalised tissue merely to obtain immediate repair.

Rehabilitation principle

Tendon healing requires protection from excessive tensile load but also benefits from controlled progressive mechanical stimulation.

Prolonged rigid immobilisation causes:

• Adhesion
• Joint stiffness
• Muscle atrophy
• Reduced tendon mechanical quality

Rehabilitation should therefore progress from protected motion to controlled strengthening according to the repaired tendon and strength of the construct.