Patella Fractures

1. PATELLA
FRACTURES
Seminar Presentation: Dr Mukul Jain
Guide: Dr Ramavtar Saini (Professor Orthopaedics)
GMCH, Udaipur, Rajasthan
11.06.2018

2. Introduction
• Largest sesamoid bone in body
• Articular surface with large lateral facet and small medial facet
• Attachments –Quadriceps Tendon
- Patellar Ligament
- Medial & Lateral Retinaculam

3. History
• Until 19th century – nonoperative
• 1940s – critical biomechanical function of patella highlighted
• 1877 – first ORIF with wiring
• 1950s – anterior tension band technique (muller)

4. • Current surgical treatment available
1.ORIF a.)TBW
b.) cannulated screw tension band technique
2 Partial Patellectomy
3 Total Patellectomy

5. • Goals of surgical treatment are
1. Restoration of the functional integrity and strength of the
extensor mechanism
2Maximizing articular congruity
3Preservation of patellar bone

6. Assessment Of patellar
Fractures
• Mechanism Of Injury
A. Direct
B. Indirect

7. • Signs and Symptoms
H/o a.direct blow to patella
b.fall from standing height
c.forceful contraction of quadriceps on a partially flexed knee
C/o anterior knee pain
swelling
difficulty ambulating after a fall

8. P/E: a.acute hemarthrosis
b.tender, palpable defect
c.Lacerations, abrasions(r/o compound # by SALINE LOAD
TEST)
• Note: the patient’s ability to extend the knee
does not rule out a patella fracture, but rather it
suggests that the continuity of the extensor
mechanism is maintained via an intact
retinacular sleeve.

9. Diagnostic Studies
• Plain Radiographs-
AP
Lateral
Tangential or axial views
• bipartite or Tripartite
Patella
-may be mistaken for # patella
-affects 8% of population
-characteristic superolateral
position
-bilateral in 50% of cases

10. • Insall salvati Ratio
(Assessment Of Patellar
Height)
Ratio of Height of Patella to
length of patellar tendon
a. Normal 1.02+/-0.13
b. Patella Alta <1
c. Patella Baja >1

11. • CT scan
-Rarely required
- imp. In evaluation of patellar stress fractures,
nonunion, malunion
• MRI (not routinely advised)
-Used to evaluate Extensor mechanism injuries
-normal xrays but is unable to straight leg raise
-chondral injuries asso. with patellar dislocations
-suspicion of osteochondral fractures

12. Classification Of patella
Fractures
• Non displaced
-Transverse
-Stellate
-Vertical
• Displaced
-Transverse
-Stellate
-Pole
-Osteochondral
-Fractures after bone tendon
bone harvest
-Masqueraders

13. Non Operative Treatment
Indications
-<3mm of fragment
dispacement or <2mm of
articular incongruity
-intact extensor machanism
-severe medical
comorbidity
-severe osteopenia
Relative contraindications
• Extensor lag or
incompetent extensor
mechanism
• >2 mm articular
incongruity
• >3 mm fracture
displacement
• Open fracture
• Loose bone or chondral
fragments

14. • Techniques
-4 to 6 weeks of extension spinting or bracing
-long leg cylindrical cast with proper moulding
-SLR and isometric quadriceps exercises
-ROM as soon as callus appears

15. Operative Treatment
• Biomechanics of Tension Band
The principle of tension band wire fixation : convert the tensile
forces generated from the quadriceps complex at the anterior cortical
surface of the patella into compressive forces at the articular surface.
• A variety of internal fixation constructs have been
performed till date.
• Preoperative Planning: Simplifying the fracture
pattern
• Surgical approaches: Midline longitudinal extensile
skin incision centered over patella

17. Surgical Steps
Modified Anterior Tension Band
• Anterior longitudinal midline incision
• Avoid unnecessary undermining of tissue
• Expose fracture and clear of debris
• Assess degree of injury and define fracture pattern
• Simplify fracture pattern with K-wires or screws when
able
• Reduce fracture
• Place two 1.6-mm K-wires perpendicularly across
fracture,
• 5 mm below anterior cortical surface
• Pass 18-gauge wire beneath patellar tendon posterior
to K-wires
• Cross limbs of wire over anterior patella
• Pass wire through quadriceps tendon posterior to K-
wires
• Tighten wires by twisting both limbs of the wire
simultaneously
• Bend ends of K-wires 180 degrees posteriorly
• Impact bent ends of K-wires into patella

18. Cannulated Screw Tension Band
• Place two cannulated screw guidewires
perpendicularly across fracture 5 mm
below anterior cortical surface
• Drill with cannulated drill over
guidewires
• Use depth gauge for screw lengths
• Insert screws
• Pass a single 18-gauge wire separately
through each cannulated screw
• Cross limbs of wire over anterior patella
• Tighten wires by twisting both limbs of
the wire simultaneously
• Bend wire twists posteriorly into deep
soft tissue

19. • Postoperative Care
*Early Range Of Motion and protected weight
bearing
*CPM to reduce postop stiffness and improve
articular cartilage healing

20. Partial Patellectomy
• Indications
-comminution of distal pole
-dysvascular or free fragments
• Contraindications
-salvageable patella
-tendon repair possible without removal of bony
fragments

21. Steps
• Anterior longitudinal midline incision
• Expose fracture
• Assess degree of injury and determine
which fragments are salvageable
• Remove nonviable patellar fragments
• Reduce and internally fix retained
fragments
• Place grasping stitch in tendon
• Reattach patellar or quadriceps tendon
through three parallel drill holes
• Secure suture over bone bridges in full
extension
• Assess strength of repair with controlled
flexion
• Consider adding cerclage wire from
quadriceps tendon to tibial tubercle
• Perform multilayer closure

22. Total Patellectomy
Indications
• Severely comminuted
fractures unable to
accept internal fixation
or suture repair
• Failed internal fixation
• Patellar osteomyelitis
Contraindications
• Ability to retain any
portion of the patella

23. Steps
• Anterior longitudinal midline
incision
• Expose fracture
• Assess degree of injury and
determine if patellar salvage is
possible
• Remove patellar fragments
• Imbricate redundant extensor
mechanism tissue with heavy
braided nonabsorbable suture
• Check extensor mechanism
tension at 90 degrees of flexion
• Perform multilayer closure
• Advance VMO

24. Thanks