This study, “Ultrasonographic Assessment of Flexor Tendon Mobilization: Effect of Different Protocols on Tendon Excursion,” is an important contribution to our understanding of flexor tendon excursion in the hand. In spite of advances in the surgical repair of lacerated flexor tendons and different modifications of both active and passive motion postoperative treatment programs, “the optimal rehabilitation program after flexor tendon repair is yet to be determined.”1 After surgical repair and healing, the goal of restoring maximum flexor tendon excursion (normally approximately 28 mm for the flexor digitorum superficialis tendon and 33 mm for the flexor digitorum profundus tendon) would allow full motion and normal function2. In this study, Korstanje et al. evaluated three currently used clinical rehabilitation protocols and two experimental models.
The following are important strengths of their research. The authors studied the effects of surrounding tissues and the effects of motion or position of adjacent fingers on the excursion of the long finger flexor digitorum profundus tendon. Included in their study were the commonly used modified Kleinert mobilization protocol and the passive four-finger mobilization protocol (hold-and-place method).
Because adjacent tissues have been shown to move in the same direction as the flexor tendon3, with greater movement proximal to the metacarpophalangeal joint and smaller movement in zone II4, adhesions attaching the tendon to these surrounding tissues can be assumed to move until they eventually limit tendon excursion. Korstanje et al. did not study cadavers or animals but rather studied normal human subjects with use of a noninvasive technique involving in vivo high-resolution ultrasound to measure the flexor digitorum profundus excursion with five postoperative motion protocols. Ultrasonography is a potential method for the measurement of flexor tendon excursion after tendon repair that has eluded hand surgeons for years. Some surgeons have suggested the use of a radiopaque marker or metallic suture in a repaired tendon to allow for the radiographic measurement of tendon excursion after tendon repair4.
The authors concluded that (1) the long finger flexor digitorum profundus tendon excursion was influenced by the position of the adjacent fingers; (2) both the absolute excursion and the relative excursion of the long finger flexor digitorum profundus tendon were decreased if the adjacent fingers remained in extension; (3) there were significant differences between the five protocols; (4) the active four-finger mobilization protocol and the passive four-finger mobilization protocol allowed the best absolute tendon excursion in comparison with the modified Kleinert mobilization protocol (the modified Kleinert protocol achieved only 43% of the absolute tendon excursion that was achieved with the active four-finger protocol and only 56% of that achieved with the passive four-finger protocol) and both experimental models; and (5) currently both experimental protocols probably do not merit use clinically (the extension model because it provided the least excursion of any method and the flexion model because of the difficulty that patients would have keeping the fingers fully flexed into the palm).
The limitations of the study were that (1) only eleven healthy subjects completed the study; (2) no actual tendon injuries were studied; (3) the surrounding tissues measured were in zone V, not in another zone, such as the important zone II; and (4) there was a potential inaccuracy of the location on the tendon that was used to measure the tendon’s excursion, namely, the accuracy of the kernel method.
This study will serve as a foundation for future clinical studies using ultrasound to measure tendon excursion in other zones, especially zone II, in prospective randomized trials of patients with repaired flexor tendon(s). Investigators can then compare at least the potential best two easily-used rehabilitation protocols (the active and passive four-finger protocols), the modified Kleinert protocol, and others as clinicians seek to prove the ideal postoperative mobilization protocol following flexor tendon repair in the hand.
↵* The author did not receive payments or services, either directly or indirectly (i.e., via his institution), from a third party in support of any aspect of this work. He, or his institution, has had a financial relationship, in the thirty-six months prior to submission of this work, with an entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. The author has not had any other relationships, or engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.
- Copyright © 2012 by The Journal of Bone and Joint Surgery, Incorporated