FLEXOR TENDON PULLEY V–Y PLASTY: AN ALTERNATIVE TO PULLEY VENTING OR RESECTION E. DONA and W. R. WALSH From the Orthopaedic Research Laboratories, University of New South Wales, Prince of Wales Hospital, Sydney, Australia Zone 2 flexor tendon repairs can require ‘‘venting’’ or partial resection of the A2 and/or A4 pulleys. We propose and biomechanically assess a technique used by the authors in which the A2 and A4 pulleys are divided and repaired using a V–Y plasty. Two groups of cadaveric fingers were used, one group for assessing the A2 pulley and the second for assessing the A4 pulley. Prepared fingers were mounted onto custom-made jigs, tested using a servohydraulic testing machine and assessed for load to failure. The loads obtained were 75N (SD ¼ 26N) and 234N (SD ¼ 73N) for the A4 and A2 pulleys, respectively. These loads are well in excess of those one would anticipate during a postoperative active mobilization protocol. Tendon pulley V–Y plasty creates a mechanically sound pulley and maintains sufficient cover of the underlying tendon. This technique provides access to perform a tendon repair and/or permits free tendon gliding post-repair, thus providing an attractive alternative to simply ‘‘venting’’, or resecting, an otherwise troublesome pulley. Journal of Hand Surgery (British and European Volume, 2006) 31B: 2: 133–137 Keywords: flexor tendon, repair, pulley, venting Flexor tendon pulleys serve to maintain a constant relationship, or moment arm, between the flexor tendon and the joint axis. In doing so, they ensure maximum joint movement for any given amount of tendon excursion (Barton, 1969; Doyle and Blythe, 1974, 1975; Idler, 1985; Idler and Strickland, 1984; Lin et al., 1989; Peterson et al., 1986). Absence of the pulley system acts to increase the moment arm of the tendon with clinically apparent tendon bowstringing. The net effect is an increased amount of tendon excursion required to produce the same arc of motion, with a potentially decreased range of motion and power. The A2 and A4 pulleys are the strongest of the annular pulleys and are considered to be the most important (Bunnell, 1918; Doyle, 1988; Doyle and Blythe, 1974, 1975, 1989; Idler, 1985; Idler and Strickland, 1984; Lin et al., 1989, 1990; Manske and Lesker, 1977, 1983). Consequently, surgeons are careful to preserve their integrity during tendon repairs. Unfortu- nately, the pulley often restricts access to the tendon making it technically difficult to perform the repair (Kwai Ben and Elliot, 1998). They can also limit tendon excursion post-repair. As a result of this, surgeons have often been forced to partially or completely divide (‘‘vent’’) tendon pulleys (Kwai Ben and Elliot, 1998; Manske and Lesker, 1983; Strickland, 1986). It has been suggested that up to 75% resection of either of the A2 or A4 pulleys will provide ‘‘clinically acceptable’’ results (Mitsionis et al., 2000; Tomaino et al., 1998). This paper assesses V–Y plasty of flexor tendon pulleys as an alternative to venting or partial resection. This technique has been employed by the authors to gain adequate exposure to the flexor tendons and to allow unrestricted tendon gliding through the pulley after repair. MATERIALS + METHODS Surgical technique The concept of V–Y plasty is not new to surgeons, although its application to tendon pulleys has not previously been described (Figs 1 and 2). V–Y plasty creates elongation of the tissue of interest with some small, but acceptable, narrowing. When this is applied to tendon pulleys, it creates increased length in the radial–ulnar axis, with shortening in the longitudinal axis. The end result is a pulley that has an increased circumference (Fig 3). Such a procedure can be performed for both the A2 and A4 pulleys. The A4 pulley requires a single V–Y plasty. However, because of its length, the A2 pulley requires two V–Y plasties side-by-side to increase the circumference along its whole length. In many clinical situations, only half of the A2 pulley requires an increase of circumference and a single V–Y plasty is sufficient. To maximize the benefit of the V–Y plasty, one needs to ensure that all three points of the ‘‘V’’ extend to the bony attachment of the pulley. The ‘‘V’’ is designed with each limb gently flared at the base and the apex of the V slightly rounded. This is done to increase the surface area of each of the tips of the three flaps created, thus maximising the suture purchase of each limb. After creating the ‘‘V’’, the clinical circumstances will dictate how far the apex of the ‘‘V’’ is advanced before repair. Generally, this would be several milli- metres. If uncertain as to how far the apex needs to be advanced, a temporary holding stitch can be placed at the apex to create the vertical limb of the ‘‘Y’’. Once this has been performed, free gliding of the tendon beneath can be assessed. When satisfied with the length of the ARTICLE IN PRESS 133