Paeds Trauma iSAWE 13

Question

A 10 year old boy falls from his bicycle. He has a tense haemarthrosis and cannot fully extend the knee.

Paeds Trauma iSAWE 13, radiograph and CT of the knee
Radiograph and CT of the knee. Image by Tsan-Wen Huang, Chien-Ying Lee, Szu-Yuan Chen, Shih-Jie Lin, Kuo-Yao Hsu, Robert Wen-Wei Hsu, Yi-Sheng Chan, Mel S. Lee, Wikimedia Commons, CC BY-SA 4.0.
  1. Describe the imaging and classify the injury.
  2. What may block reduction?
  3. Outline management.

Answer

Imaging

  • Avulsion fracture of the tibial eminence
  • The paediatric equivalent of an ACL rupture
  • Incomplete ossification makes bone weaker than the ligament

Meyers and McKeever

TypeDescription
IUndisplaced
IIAnterior elevation, posterior hinge intact
IIICompletely displaced
IVDisplaced and comminuted or rotated (Zaricznyj)

Block to reduction

  • Entrapment of the anterior horn of the medial meniscus or intermeniscal ligament
  • Present in many type II and III injuries
  • MRI to assess entrapment and other injuries

Management

  • Type I, cast or brace in near extension
  • Type II, attempt closed reduction in extension, fix if not reduced
  • Type III and IV, arthroscopic or open reduction and fixation
  • Suture fixation avoids hardware crossing the physis
  • Epiphyseal screws avoid the physis
  • Arthrofibrosis is the main complication, start early motion
  • Residual laxity is common but symptomatic instability is uncommon

Related pages

Author Contributions

Orthofracs team

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.