Immobilization Duration for Posterior Patella Fractures
For nondisplaced posterior patella fractures, immobilization should be maintained for 4-6 weeks with serial radiographic monitoring during the first 3 weeks to confirm the fracture remains nondisplaced. 1
Rationale for Immobilization Duration
The 4-6 week timeframe is based on fundamental fracture healing principles:
- Mechanical stress perpetuates bone injury and prevents healing, making immobilization crucial for maintaining fracture stability in nondisplaced patella fractures 1
- Progressive deformity can develop without adequate immobilization, as demonstrated in other fracture types where early motion leads to malalignment 1
- The immobilization period allows sufficient time for initial fracture consolidation while preventing displacement from quadriceps muscle forces
Critical Monitoring Protocol
Serial radiographic evaluation during the first 3 weeks is essential to detect any loss of reduction early 1. This monitoring period is critical because:
- Most displacement occurs in the early healing phase when fracture stability is most vulnerable 1
- Early detection of displacement allows for timely surgical intervention if needed
- After 3 weeks, if the fracture remains nondisplaced, continued immobilization until 4-6 weeks is typically sufficient
Type of Immobilization
Rigid immobilization is preferred over removable splints for displaced or unstable fractures 2. For nondisplaced posterior patella fractures:
- A cylinder cast or knee immobilizer in full extension is typically used to eliminate quadriceps pull
- The knee should be maintained in extension to minimize forces across the fracture site
- Functional bracing may be considered after initial healing is confirmed radiographically
Important Caveats
- If displacement occurs during the immobilization period, surgical intervention becomes necessary 3
- The length of immobilization showed no statistical significance in outcomes for operatively treated fractures 4, but this does not apply to conservatively managed nondisplaced fractures
- After immobilization, intensive quadriceps rehabilitation is essential, as muscular status determines functional outcomes more than residual laxity 5