ContentsSynopsisCodesLook ForDiagnostic PearlsDifferential Diagnosis & PitfallsBest TestsManagement PearlsTherapyReferencesView all Images (10)
Patellar fracture
Other Resources UpToDate PubMed

Patellar fracture

Contributors: Robert Lachky MD, Eric Ingerowski MD, FAAP
Other Resources UpToDate PubMed

Synopsis

The patella is the largest sesamoid bone in the body, and it functions to direct the forces exerted by the quadriceps muscles. Patients with patella fracture will have pain / swelling over the knee with large knee effusion and tenderness over the patella.

Fracture can be caused by direct or indirect forces.
  • Direct impact to patella can occur from a fall on a flexed knee landing directly on patella or motor vehicle crash. This can result in a transverse fracture pattern (more common in younger adults) or a comminuted fracture (more common in elderly patients and those with osteoporotic bone).
  • Indirect impact can occur with sudden flexion of the knee against a contracted quadriceps muscle (depending on the force and properties of the muscle / bone / tendon, something in the patient's extensor mechanism will break, whether it is the quadriceps tendon, the patellar tendon, or the patella itself). Avulsion fractures involve the superior / inferior pole.
Osteochondral lesion of patella is discussed separately.

Codes

ICD10CM:
S82.009A – Unspecified fracture of unspecified patella, initial encounter for closed fracture

SNOMEDCT:
51037009 – Fracture of patella

Look For

Subscription Required

Diagnostic Pearls

Subscription Required

Differential Diagnosis & Pitfalls

Best Tests

Subscription Required

Management Pearls

Subscription Required

Therapy

Subscription Required

References

Subscription Required

Last Reviewed:06/28/2019
Last Updated:03/26/2021
Copyright © 2021 VisualDx®. All rights reserved.
Patellar fracture
Copyright © 2021 VisualDx®. All rights reserved.