Incidental Finding of a Thorn in the Left Knee Joint of an Amateur Football Player and Arthroscopic Removal: A Case Report

JBJS Case Connect. 2021 Jul 15;11(3). doi: 10.2106/JBJS.CC.21.00237.


Case: A 19-year-old male amateur footballer was referred to our center with complaints of relapsing and remitting pain, swelling, and reduced range of motion of the left knee. History, radiological, and laboratory findings were unrevealing, except for chronic synovitis. On arthroscopy, a 3.3 × 0.3-cm thorn was found embedded in the anteromedial aspect of the anterior cruciate ligament and was carefully removed. The postoperative course was uneventful.

Conclusion: The foreign body must be considered as differential diagnoses in players presenting with unilateral chronic synovitis of the knee. Knee arthroscopy is the gold standard for both diagnostic and therapeutic purposes when the history is unclear, and radiological investigations are inconclusive.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Anterior Cruciate Ligament / surgery
  • Arthroscopy / methods
  • Football*
  • Humans
  • Incidental Findings
  • Knee Joint / diagnostic imaging
  • Knee Joint / surgery
  • Male
  • Young Adult