Coding and Management of Displaced Patella Fracture After Failed Conservative Treatment
When a patella fracture initially treated non-operatively subsequently displaces and requires surgery, proceed with open reduction and internal fixation (ORIF) using tension band wiring with cannulated lag screws, and code this as a definitive surgical treatment rather than a failed conservative attempt. 1
Immediate Surgical Intervention
Displaced patella fractures that disrupt the extensor mechanism require operative treatment to restore unassisted gait capability. 1 The key clinical finding that mandates surgery is loss of extensor mechanism integrity—specifically, the inability to perform a straight leg raise against gravity indicates complete disruption requiring surgical repair. 1
Optimal Surgical Technique
For horizontally displaced two-part fractures (the most common pattern requiring conversion to surgery):
- Use two parallel cannulated lag screws combined with tension band wiring as the treatment of choice, as this provides superior biomechanical stability compared to tension band wiring alone. 2
- Open reduction with internal fixation remains the gold standard approach for displaced fractures with extensor mechanism disruption. 1
- Modified tension band wiring can be used for almost every fracture type, though supplementation with interfragmentary screws significantly improves construct stability. 1, 2
When Fracture Pattern Precludes Standard Fixation
If comminution has developed during the period of conservative treatment:
- Consider supplementing or replacing the tension band construct with cerclage wire/suture and/or plate-and-screw constructs to achieve adequate stability. 1
- Partial patellectomy may be necessary for severely comminuted fractures, though this should be avoided when possible due to loss of quadriceps power. 2
- Total patellectomy should be considered only as a salvage procedure given the poor functional outcomes and significant quadriceps weakness that results. 2
Critical Timing Considerations
Early surgical intervention after displacement is preferable to delayed treatment. 3 A case report of a 2-year-old neglected displaced transverse patella fracture demonstrated that delayed surgery resulted in only 80 degrees of flexion and persistent functional limitations, highlighting the importance of timely intervention. 3
Rehabilitation Protocol
- Initiate early rehabilitation regardless of treatment method to optimize functional outcomes. 2
- Begin range of motion exercises as soon as the fixation construct allows, typically within the first few weeks postoperatively. 2
- Consider leaving the lateral retinaculum open if significant stiffness is anticipated, as this may provide better motion recovery. 3
Expected Outcomes and Complications
Patients should be counseled that patellofemoral arthrosis is very common after healing of patella fractures, and substantial functional deficits may persist long after fracture healing. 1 Common complications following ORIF include:
- Symptomatic hardware requiring removal 4
- Posttraumatic arthritis 4
- Arthrofibrosis 4
- Extensor mechanism insufficiency 4
- Nonunion and infection (less common but serious) 4
Coding Approach
Code this scenario as a definitive surgical procedure (ORIF of patella fracture) rather than attempting to capture the failed conservative treatment separately. The clinical documentation should clearly note:
- Initial conservative management with subsequent displacement
- Loss of extensor mechanism integrity necessitating surgery
- Specific surgical technique employed (e.g., ORIF with tension band wiring and cannulated screws)
The displacement after initial conservative treatment represents a change in fracture pattern that mandates surgical intervention, not a surgical complication or treatment failure requiring separate coding. 1