Bipartite Patella

Ossification

 

Patella may develop from one or multiple ossification centres at 3 years

 

Failure of centres to fuse may produce bipartite or tripartite patella

- usually bilateral and painless

 

Classically superolateral

 

Classification Saupe

 

I   Inferior Pole 5%

II  Lateral 20%

III Superolateral 75%

 

Xray

 

Bipartite patella SuperolateralBipartite patella

 

CT

 

Bipartite Patella CT

 

MRI

 

Look for increased uptake ? symptomatic

 

Bipartite patella MRI

 

Clinical

 

1.  Overuse

- pain may result from repetitive microtrauma 

- injury to synchondrosis

- point tender & swollen

 

2. Acute injury

- can get acute injury with minor separation

- reports of bipartite patella healing post injury

- check SLR to ensure quadriceps tendon intact

 

Management 

 

Non operative Management

 

Majority will settle with non operative management

- mmobilisation for 4 weeks

- avoid impact sports

 

Ultrasound / Exogen

- reports of healing bipartite patella post injury

 

Operative Management

 

Options

 

Lateral release

 

Adachi et al Arthroscopy 2002

- lateral release performed

- excellent results in 13 and good in 4

- nearly 2/3 healed and remainder partially healed

- bone union more likely in patients < 15

 

Mori et al Am J Sports Med 1995

- 15/16 united at 8 months post lateral release

 

Removal of bipartite patella

 

A. Open

- easiest

- often need to reattach quadriceps tendon with anchors

 

B. Arthroscopic

 

Bipartite PatellaBipartite Patella