Abstract
In the 1970s, Boyes pointed out the problem of flexor tendon repairs sticking under the A2 pulley, the tightest part of the sheath (Boyes and Stark, 1971). This article is too small to define how we move forward to avoid this problem in zone 2C and the authors apply too much science to their small study. However, it is important.
In 1994, Professor Tang showed better results for simple Zone 2C flexor tendon injuries when only the flexor digitorum profundus (FDP) was repaired (Tang, 1994). In 1998, we could not corroborate this for simple flexor tendon divisions in our work and, for a time, I believed that flexor digitorum superficialis (FDS) tendon sacrifice was only necessary under circumstances likely to result in significant oedema in the distal palm. More recently, I have come round to Professor Tang’s view that FDP repair only is wise for any injury under the A2 pulley as an acknowledgement of the reality: (i) that the complex anatomy below the A2 pulley of the FDS tendon wrapping itself around the FDP tendon makes a double pulley; (ii) that the sutured tendon is inevitably thicker than the original; and (iii) that most flexor tendon repairs are done, worldwide, by surgeons with less skill than the best of senior hand surgeons who may obtain ideal repair of both tendons in this area. The expertise to achieve free tendon movement after repair of both FDS and FDP tendons in zone 2C with partial divisions of the A2 pulley, even up to removal of two-thirds of its length, may not be always be present.
This article suggests a simpler, but not new, policy of complete A2 division. Yet again, we must acknowledge the research work of Savage (1990), who showed that division of the A2 pulley caused no significant change to function, provided the remainder of the sheath, including the A1 pulley, remained intact. In addition, earlier surgeons who, believing in healing by extrinsic adhesions, were no respecters of the pulleys, as shown in the writings of Mason (1940): ‘ The sheath is just large enough for its contents and provides scarcely enough space for repair of one tendon. The fibrous sheath is excised for a distance of about 1/4 inch above and below the suture line’; and Verdan (1958): ‘The sheath is excised over a distance of about 2 to 3 cm; the amount of sheath to be resected was determined by estimating the physiological gliding amplitude at this level’.