A 19-year-old male presented with knee pain after falling during a basketball game. Radiographs revealed a bipartite patella, which is a congenital condition where the patella fails to fuse, seen in 2-3% of the population. It is typically asymptomatic but can cause anterior knee pain aggravated by activity. Non-operative management is indicated initially but surgical excision may be needed if non-operative treatment fails after 6 months or for displaced fragments. The main risk of surgery is patellofemoral maltracking.

1. BIPARTATE PATELLA
DR ANIL KUMAR P
JUNIOR RESIDENT
DEPT OF ORTHOPAEDICS
SDUMC KOLAR

2. A 19-year-old male complains of two week
history of knee pain after falling during a
college basketball game. Physical exam is
unremarkable with no signs of effusion or
focal tenderness. the following
radiographs were obtained.

4. INTRODUCTION
• A bipartite patella is a congenital condition
caused by failure of the patella to fuse
• It is considered a developmental variation of
ossification
• It is typically asymptomatic, found incidentally
• Normal patella variant representing a failure of
fusion often confused with patella fractures

5. ANATOMY
Osteology
• The patella is the largest sesamoid bone
• Arises from a single ossification center
Ossification
• Males at 4-5 years
• Females at 3 years
• Accessory ossification center appears between
8-12 years

6. HISTOLOGY
• Tissue between accessory and main fragment is
composed of fibrocartilage > fibrous > hyaline
cartilage and avascular
• Adjacent bone has scalloped surface with
numerous osteoclasts and well-vascularized

7. Epidemiology
Incidence
• 2-3% of the population
Location
• Most often found in the superolateral region
(type III)
• Bilateral found in 50%

8. PATHOPHYSIOLOGY
• Direct or indirect injury results in disruption of the
fibrocartilaginous zone between the main patella
and accessory fragment.
• Fibrocartilaginous zone cannot heal by bony
union, resulting in persistent pain.
• Vastus lateralis contributes to traction force in
fragment separation and nonunion

9. • The pain is aggravated by activity and may be
reproduced by direct palpation

10. BLOOD SUPPLY
From popliteal artery
• Superior lateral
• Superior medial
• Inferior lateral
• Inferior medial geniculate artery
From superficial femoral artery
• Supreme geniculate artery
From anterior tibial artery
• Anterior tibial recurrent artery

12. SAUPE CLASSIFICATION
Saupe Classification
Type Incidence Location
Type I 5% Inferior pole
Type II 20% Lateral margin
Type III 75% Superolateral pole

14. PRESENTATION
• Most are asymptomatic and discovered
incidentally
• Only 2% become symptomatic
• Anterior knee pain
• Pain aggravated by squatting, jumping, climbing
stairs

15. EXAMINATION
• Localized tenderness over accessory fragment
(typically superolateral patella)
• Hematoma
• Restricted range of knee motion
• Unusual patella prominence or palpable defect
• Larger than normal patella

16. IMAGING
• AP knee radiograph -best view to visualize
bipartite patella
• Skyline view
– Prone position (non-weight-bearing)
– Squatting position (weight-bearing)
– May show displacement of the accessory
fragment
• Weight-bearing skyline (squatting) view
demonstrates increased separation of
fragments compared with non-weight views
(prone)

18. CT SCAN
•
• Will clearly demonstrate fragment, but does not
demonstrate edema

19. MRI
Indications
• Assessment of painful bipartite patella to
determine if pain is attributable to the bipartite
patella
Findings
• Edema around the fragment may indicate that it
is the cause of symptomatic knee pain

21. TREATMENT
NON-OPERATIVE
• Generally, non-operative, symptomatic
management is indicated for bipartite patella for
at least 6 months
• Rest, immobilization, NSAIDS, and physical
therapy
• Rest and restriction of sports activities
• NSAIDS
• Isometric quadriceps strengthening exercises

22. • Immobilization with the knee braced in 30° of
flexion
• Local corticosteroid injections
• Non-operative management may be less
successful in younger, athletic patients, possibly
due to non-compliance

23. OPERATIVE MANAGEMENT
I. Open excision of the accessory fragment
Indications
• Failed non-operative treatment >6 months
• In cases of a displaced fragment requiring
reduction
• Direct trauma resulting in the onset of pain
• Significant impairment in daily activities
• Most common treatment technique, typically good
results

24. Arthroscopic excision
• Lead to faster recovery and avoids disrupting
the quad tendon
Lateral retinacular release
• Indications
• Supero-lateral fragment (to remove the traction
force of the vastus lateralis on the fragment)

27. Complications
• Patellofemoral maltracking
– due to excision of a large fragment or lateral
retinacular release
– may lead to patellofemoral degenerative
changes
• Effusion
• Persistent knee pain
• Quadriceps weakness
• Osteonecrosis

29. Summary
• Failure of the patella to fuse
• Developmental variation of ossification
• Asymptomatic, found incidentally
• Single ossification center
• Accessory and main fragment is composed
of fibrocartilage which cannot heal by bony
union, resulting in persistent pain

30. • Major blood supply is from geniculate artery
• Saupe classification
• Pain tenderness restricted ROM
• AP and squatting skyline view is best viewed for
fragments
• Symptomatic treatment for 6 months f/b surgical
management

31. •THANK YOU

32. • Associated conditions
– nail-patella syndrome
– Nail–patella syndrome is a genetic disorder that results in
small, poorly developed nails and kneecaps, but can also affect
many other areas of the body, such as the elbows, chest, and
hips
– patella fracture
• compared with patella fractures, bipartite patellas:
– are located superolaterally
– have smooth, rounded borders