dislocation of patella

Dislocation Of Patella.

Types

• Acute

• Recurrent

• Habitual

1. Acute

• Result 4m sudden contraction of quadriceps while the knee is flexed or semi-flexed.

• Dislocates laterally• C/F:

– Pain– Swelling– Unable to straighten the knee– Medial condyle(Femur) more prominent – Tenderness (antero-medially)

Treatment:

• Reduction- Under Gen. anesthesia

• Immobilisation: cylinder cast—3 weeks

Recurrent D/L

• Etiology:– Congenital

• Lig. Laxity• hypoplasia of lat. Femoral condyle• Flattening of Intercondylar groove• Patellar maldevelopment• Primary muscle defect• Genu valgum

– Acquired• Genu valgum• Inequality of growth of condyle• Weakness of Quads• Contracture• fibrosis

PathologyFirst episode

Tear of capsule on medial side of patella

If improper healing

Persistent laxity

Recurrent d/l

Damage to contiguous surface of patella & fem. Condyles

Flattening & then further d/l

C/F• More common in girls• Often B/L• Acute pain with knee stuck in flexion• In dislocated state:

– Visually obvious– Tenderness– Swelling

• Between attack– Patella alta– Gen. lig. Laxity– Apprehension test +ve

Investigation:

• X-ray– Dislocation – High-riding patella– Other anatomical abnormality

• MRI

• CT-SCAN

Treatment

• Conservative– Quads exercise– NSAIDS

• Operative– Camphell Op.– Goldwait op.– Hauser’s op.– Patellectomy– Muscle release with V-Y Z-plasty

Habitual D/l

• Everytime knee is flexed, It dislocates laterally

• Present in early childhood

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