If a patellar tendon injury is suspected, should the patient be immobilized?

Immobilization for Suspected Patellar Tendon Injury

Yes, patients with suspected patellar tendon injury require immediate immobilization in a knee extension splint or brace to prevent further damage and facilitate optimal surgical repair outcomes. 1, 2, 3

Immediate Management Algorithm

Initial Immobilization Requirements

• Apply a rigid knee extension splint immediately when patellar tendon rupture is suspected, keeping the knee in full extension 1
• The splint must be padded to prevent pressure points and should be comfortably tight but allow one finger to slip underneath to ensure adequate circulation 1
• Do not attempt to straighten the knee or manipulate the injury before splinting 4

Clinical Indicators Requiring Immobilization

Suspect complete patellar tendon rupture and immobilize if the patient presents with:

• Palpable defect in the patellar tendon 2, 3
• Inability to actively extend the knee against gravity 2, 3
• Patella alta (high-riding patella) on lateral radiographs 2
• Localized patellar tendon tenderness 3

Critical Rationale for Immobilization

Time-Dependent Outcomes

The interval between injury and surgical repair is the most important prognostic factor for successful outcomes 2, 3. Immobilization serves to:

• Prevent further tendon retraction and tissue damage that would complicate delayed surgical repair 2
• Minimize the risk of compromised results including loss of knee flexion and decreased quadriceps strength that occur with delayed repair 2
• Protect the extensor mechanism until definitive surgical treatment can be performed 3

Complications of Non-Immobilization

Failure to immobilize can result in:

• Progressive tendon retraction making surgical repair technically more difficult 2
• Increased morbidity from this already debilitating injury 3
• Compromised functional outcomes even after eventual repair 2

Immobilization Specifications

Device Parameters

• Use a rigid knee extension splint with dorsal or volar design 1
• Ensure the splint permits one finger to slip underneath to verify adequate circulation 1
• Elevate the leg above heart level when splinted to minimize swelling 1

Safety Monitoring

Instruct patients to report immediately if they develop:

• Blue, purple, or extremely pale discoloration of toes/foot (indicates circulatory compromise requiring emergency intervention) 1
• Numbness, tingling, or inability to move the toes (suggests neurovascular compromise) 1
• Unremitting pain during immobilization 4

Adjunctive Measures During Immobilization

• Apply ice-water mixture for 15-20 minutes several times daily during the first week if pain or swelling present 1
• Allow active motion of ankle and hip joints to prevent stiffness 1
• Perform ankle pumps and hip exercises multiple times during the immobilization period 1

Important Clinical Caveats

Partial vs. Complete Tears

• Incomplete, partial tears can be managed nonsurgically with immobilization and progressive rehabilitation 3
• Complete ruptures require surgical repair, and immobilization serves as a bridge to definitive treatment 3

Duration Considerations

• Immobilization is a temporary measure pending surgical evaluation and repair 2, 3
• For complete tears, surgery should be performed as soon as possible after injury for optimal results 2, 3
• Prolonged immobilization beyond what is necessary can lead to complications including deep vein thrombosis 5

Common Pitfall to Avoid

Do not delay radiographic evaluation or surgical referral while maintaining prolonged immobilization. The diagnosis should be confirmed promptly with imaging (radiographs, ultrasound, or MRI), and complete ruptures should proceed to surgical repair without unnecessary delay 2, 3. Time to surgery remains the most important prognostic factor 3.