From the Research
Bipartite patella is a normal anatomical variant that does not require treatment unless it becomes symptomatic, in which case arthroscopic management is a safe and effective alternative to open surgical excision or release, as demonstrated by the most recent study in 2021 1.
Definition and Prevalence
Bipartite patella is a condition where the patella appears to be divided into two separate ossification centers on X-rays, most commonly affecting the superolateral portion of the patella. This occurs in approximately 2-3% of the population and is bilateral in about 50% of cases.
Diagnosis and Classification
On X-ray, bipartite patella appears as a separate bone fragment with smooth, well-corticated margins adjacent to the main patellar body, often with a radiolucent line between the fragments. The classification system includes three types: Type I (inferior pole), Type II (lateral margin), and Type III (superolateral pole, most common at 75% of cases).
Treatment
Most cases of bipartite patella are asymptomatic and discovered incidentally on imaging, requiring no treatment. However, if symptoms persist, arthroscopic management, including lateral release or excision of the accessory fragment, can provide excellent results, with 100% of patients being pain-free and able to return to sports after a mean of 2.6 months, as reported in the 2021 study 1. Other treatment options, such as open fragment excision or lateral retinacular release, have also been shown to be effective, but may have higher complication rates and longer recovery times, as noted in earlier studies 2, 3, 4.
Key Points
- Bipartite patella is a normal anatomical variant that does not require treatment unless symptomatic.
- Arthroscopic management is a safe and effective treatment option for symptomatic bipartite patella.
- The classification system includes three types: Type I, Type II, and Type III.
- Most cases are asymptomatic, but if symptoms persist, treatment options include arthroscopic management, open fragment excision, or lateral retinacular release.