From the Guidelines
Lucency around hardware in the foot does not necessarily mean a nonunion, though it can be one possible explanation, as evidenced by the complex interplay of factors such as loosening, osteolysis, and instability in total knee arthroplasty failure 1. When evaluating lucency around hardware in the foot, it's crucial to consider the timing and progression of the lucency, as well as other clinical factors such as pain, inability to bear weight, or visible motion at the fracture site.
- Normal bone remodeling can cause some lucency immediately after surgery, which may not be a concern.
- However, progressive lucency over time may indicate a complication such as hardware loosening, infection, or inflammatory response to the implant.
- The pattern and progression of lucency, time since surgery, and patient symptoms must be carefully evaluated by an orthopedic surgeon to determine if a nonunion exists or if another cause is responsible for the lucency.
- Additional imaging studies may be necessary to assess the extent of the lucency and guide further management, as seen in the evaluation of rotational instability of total knee arthroplasty 1.
- It's essential to note that the concepts of instability, malalignment, and loosening are closely interrelated, and minor degrees of instability can become a significant problem over time, potentially leading to loosening or other complications 1.
From the Research
Definition of Nonunion
- Nonunion is a condition where a fracture does not heal properly, and the bone does not unite as expected 2, 3, 4, 5, 6.
Factors Contributing to Nonunion
- Biological factors, such as impaired biology and metabolic disorders, can contribute to nonunion 2, 6.
- Mechanical factors, including loose or failing hardware, can also contribute to nonunion 3.
- Patient factors, such as infection, can also play a role in nonunion 2, 3, 5.
Lucency Around Hardware
- Lucency around hardware in the foot may indicate a nonunion, but it is not a definitive diagnosis 3.
- The presence of lucency around hardware can be a sign of loose or failing hardware, which can contribute to nonunion 3.
Diagnosis and Treatment of Nonunion
- Diagnosis of nonunion often requires assessment and treatment of multiple factors, including biological, mechanical, and patient factors 2, 6.
- Treatment of nonunion may involve hardware removal, bone grafting, and other surgical procedures 3, 5, 6.
- Teriparatide, a parathyroid hormone analogue, has been shown to be effective in treating delayed union and nonunion in some studies 4.