Flexor Carpi Radialis Tendon Rupture from Scapho-Trapezio-Trapezoid Osteoarthritis: A Case Report and Review of Literature.

Subcutaneous rupture of the flexor carpi radialis (FCR) tendon from scapho-trapezio-trapezoid (STT) osteoarthritis is a rarely reported and diagnosed condition. A 65-year-old female presented in the clinic with wrist pain aggravated with movement. On physical examination, there was a 2-cm soft elastic mass at the radial side of the volar wrist. There was no tenderness, but pain was elicited with range of motion. Computed tomography confirmed an osteoarthritic STT with large spurs. Magnetic resonance imaging (MRI) showed impingement on the tract of the FCR associated with synovitis. Complete rupture was noted intraoperatively. Interpositional arthroplasty with palmaris longus tendon ball transfer was done after removing the bone spurs and minimal resection of the joint. At follow-up 4 months later, the patient was pain-free after a brief period of immobilisation. We present a novel approach to STT osteoarthritis with FCR rupture, which avoids the complications and disadvantages of STT fusion, promoting early rehabilitation. Level of Evidence: Level V (Therapeutic).