Sliding Position of the Flexor Tendons Relative to the Hook of Hamate in CT Scans.

BACKGROUND: The aim of this study was to assess the height of nonunion formation injuring the ulnar-side finger flexor tendon, the positional relationship between the hook of the hamate and little finger flexor tendon was evaluated on CT scans.

METHODS: The subjects were 20 healthy patients (40 hands) (14 males and 6 females, mean age: 28 years old). Their hands were imaged in extension and flexion of the fingers on CT. The position of the little finger flexor tendon was determined regarding the height of the hook of the hamate as 100%.

RESULTS: The heights of the flexor digitorum profundus tendons were 46 ± 6% in extension and 44 ± 9% in flexion, and those of the flexor digitorum superficialis tendons were 87 ± 8% in extension and 91 ± 9% in flexion.

CONCLUSIONS: Our study suggested that 40% of the base of the hook of the hamate does not contact with the flexor tendon, suggesting that flexor tendon injury is unlikely to occur in that region.