Finger Enthesophytes at the Flexor Digitorum Superficialis Insertion in an Avid Bowler: A Case Report

Enthesophytes are bony spurs that form at the insertion sites of ligaments, tendons, or articular capsules on bone, also known as entheses. In the hand, they commonly form due to inflammatory disorders but can also form due to mechanical stress. It is hypothesised that the mechanical loads cause micro-damage of the fibrocartilaginous enthesis, which results in new bone formation from osteoblast differentiation. We present a unique case where a patient formed enthesophytes at the flexor digitorum superficialis (FDS) insertion site of the long and ring fingers, which the authors believe could be due to the mechanical stresses caused by bowling. He was managed conservatively with observation.