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PATELLAR FRACTURES

Dr. D. N. Bid

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Definition• Patellar #s are classified as either non-displaced

or displaced. Those that are less than 1-2 mm articular step-off or 3 mm of fragment separation displaced are considered nondisplaced #s.

• Patellar #s may also be described as transverse, longitudinal, or comminuted.

• Extraarticular patellar #s involve the poles of patella and are usually secondary to avulsion injuries.

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Transverse patellar # with

retinacular tear.

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Patellar #s may be described as longitudinal or comminuted.

These #s are intra-articular.

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Mechanism of Injury

• A direct blow to the patella accounts for the majority of patellar fractures.

• Indirect force from a violent contraction of the quadriceps muscle can also result in a patellar #.

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Treatment Goals

• Orthopaedic Objectives–Alignment• 1. Fracture Displacement.• 2. Articular congruity.

– Stability • Stability is best achieved by restoring bony congruity

and using hardware to rigidly fix the #.

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• Rehabilitation Objectives• Range of Motion

• Muscle strength

• Functional Goals

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• Rehabilitation Objectives• Range of Motion– 1. Restore full ROM of the knee in flexion and

extension to prevent extension lag.– 2. Restore the rectus femoris (two joint muscle) to

its full length so as to achieve full ROM of the hip and knee.– 3. Maintain ligamentous flexibility, which may be

reduced secondary to trauma and immobilization.

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• Rehabilitation Objectives• Muscle strength–A) improve the strength of the quadriceps

muscle.–B) improve the strength of the hamstrings

muscles.–C) improve the quadriceps-hamstring

balance.

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• Rehabilitation Objectives• Functional Goals– Normalize the gait pattern, specially in stance

phase. – Undertake proprioceptive and sport specific

training.

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Expected time of Bone Healing

8-12 weeks

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Expected Duration of Rehabilitation

12-15 Weeks

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Methods of Treatment

• Cast or Knee Immobilizer

• Open Reduction and Internal Fixation

• Partial / Total Patellectomy

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Transverse patellar fracture with intraarticular involvement

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Transverse patellar fracture treated with

lag screw fixation.

This is stress shielding device unless solid fixation

is not achieved.

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Transverse patellar # with

displacement.

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Transverse patellar # treated with tension

band wiring.

As the quadriceps muscle attempts to separate #

fragments, the wire tightens, forcing them back together.

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Tension band fixation for a transverse patellar #.

The parallel wires control alignment and the tension

band wire tightens with any attempt to distract the

fracture.

This is a stress sharing device.

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Special considerations of the Fracture

• Bipartite Patella

• Long term sequelae

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• Bipartite Patella– Frontal view of the knee

demonstrates the characteristic appearance of a bipartite patella.

– The ununited ossification center is typically in the upper, lateral aspect of the patella (red arrow). This occurs in about 2% of the population, is much more common in males and is bilateral 57% of the time.

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Associated Injury

• Retinacular tear

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• Weight bearing

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Gait CycleWhat is the effect during each phase?

• Stance Phase– Heel strike– Foot flat– Mid-Stance– Push off

• Swing Phase– Acceleration– Mid-swing– Deceleration

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Treatment

• Treatment: Early to immediate (Day One to One week)

• Treatment: Two weeks

• Treatment: Four to Six weeks

• Treatment: Eight to Twelve weeks

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Long Term Considerations and Problems

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Thank You