Prospective morphologic and dynamic assessment of deep flexor tendon healing in zone II by high-frequency ultrasound:...

The purpose of this article is to prospectively evaluate early postoperative morphologic and functional changes after deep flexor tendon repair in zone II using ultrasound and to correlate findings from ultrasound with the clinical outcome.

Ten patients (mean age, 34 years; range, 19-55 years) with 11 injured deep flexor tendons of the hand underwent surgical tendon repair. Postoperative tendon morphology was assessed with gray-scale and power Doppler ultrasound over a period of 3 months. Tendon excursion over the proximal interphalangeal joint was assessed by sonographic scar tracking. Correlation of ultrasound findings with clinical outcome was performed.

Almost all repaired tendons exhibited a spindlelike shape after 1 week, of which 50% developed a normal shape after 12 weeks. A persisting spindlelike shape over 3 months was associated with a significantly increased tendon excursion (p < 0.05) and a trend toward better active motion of the fingers (p = 0.056). Tendons with increased power Doppler signal showed a significantly better tendon excursion and active motion after 12 weeks (all p < 0.05). Tendon excursion measurements obtained by scar tracking showed excellent correlation (r = 0.84; p < 0.05) with total active finger motion.

Preliminary data of this study indicate a better clinical outcome if a sutured tendon maintains a spindlelike shape and increased power Doppler signal. This might indicate a predominantly intrinsic healing pattern with reduced adhesion formation. Ultrasound morphology, power Doppler signal, and tendon excursion may be helpful tools to rate tendon healing and to establish individually modified rehabilitation protocols.