Snapping Junctura Tendinum to the Small Finger Simulating Radial Sagittal Band Rupture: A Report of Two Cases

Author(s): Jeon I, Seok J, Choi J, Lee Byung-Woo, Kim Shin-Yoon, Kim Poong-Taek

Source: J Bone Joint Surg  Am 91: 1219-1222, 2009.

Summary:

The authors report two cases of snapping junctura tendinum within the 4-5 intermetacarpal space found operatively in patients presumed to have radial sagittal band rupture.  Pathologic painful snapping is usually associated with the long and ring finger with ulnar subluxation of extensor tendon following radial sagittal band rupture.  The authors also present their method of surgical treatment.

Both patients were females with new onset of painful snapping of the small finger.  One patient had a new activity associated with overuse and the other blunt trauma to the 4-5 intermetacarpal space.  Examination identified radial subluxation of the extensor tendon to the small finger at 30 degrees of MP flexion.  At the time of surgery, the radial sagittal band was noted to be intact.  Both patients were noted to have a thickened type 3 junctura tendinum which snapped at 30 degrees intraoperatively.

The junctura was incised at the ring extensor and sutured to the radial slip of the EDQ.  Patients were progressed from 2weeks immobilization to PROM (4weeks) to full AROM at 6 weeks.  Both patients hand full function of the hand without recurrence at two years follow-up.  The authors conclude that a thickened junctura tendinum should be included in the differential diagnosis for painful snapping of the small finger.