Knee · Acute injury

Patella Fracture

Fracture of the kneecap — from a direct blow or sudden forceful contraction of the quadriceps.

Cared for across all 6 OSI locations

Overview

what it is and why it matters
Front view of the knee showing the femur, tibia, patella, cruciate and collateral ligaments, and the medial and lateral menisci.
Knee anatomy. The knee is the meeting point of the thigh bone (femur), shin bone (tibia), and kneecap (patella). Four ligaments hold it together — the ACL and PCL inside the joint and the MCL and LCL on the sides — and two C-shaped menisci cushion the joint surfaces.
Blausen Medical · Wikimedia Commons · CC BY-SA 4.0

Patella fractures occur from a direct blow (fall onto the knee, car dashboard) or from an indirect mechanism — the sudden eccentric load of the quadriceps during a stumble can pull the patella apart. The extensor mechanism of the knee — quadriceps tendon, patella, patellar tendon, tibial tubercle — must be intact for active knee extension. Patellar fractures that disrupt this mechanism require operative repair.

Diagnosis

exam first, imaging second

Anterior knee pain, inability to do a straight-leg raise (indicating extensor mechanism disruption), and a palpable gap in the kneecap. AP, lateral, and Merchant X-rays of the knee confirm the fracture and its displacement. CT further characterizes comminuted patterns.

Treatment Path

how care progresses at OSI
1

Non-operative management

For non-displaced fractures with an intact extensor mechanism: cylinder cast or hinged brace in extension for 4–6 weeks with progressive weight-bearing.

Surgical Options at OSI

if non-operative care isn't enough

Displaced fractures (> 2–3 mm articular step or gap), comminuted fractures with extensor mechanism disruption, and osteomyelitis and septic…">open fractures require surgery.

Providers Who Treat Patella Fracture

sports-medicine team

Michael S. Vrana, M.D.

David B. Templin, M.D.

Trent Twitero, M.D.

Further Reading

authoritative sources

External patient-education references and related OSI pages for additional background:

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