Orthopaedic Hand Trauma CH35

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SECTION 3  | Tendon Injuries

classification of the injury. It is important to determine the extent of injury at the time of diagnosis because certain cases require surgical correction within 7 to 10 days of the injury. Timely management is recommended in all cases, because it can be difficult to determine the degree of retraction of the tendon on physical examination. ■ ■ Type I/II ● ● Surgical options include dorsal button, direct tie around bone, suture anchor, or a combination of techniques. ● ● An attempt to localize the level of retraction preoperatively should be made using physical examination and imaging modalities. Intraop- eratively, the tendon is identified using a Bruner approach, in which a volar zigzag incision is made from the level of tendon retraction proximally to the distal DIP joint. The flexor sheath is then exposed. An incision is made just distal to the A2 pulley to locate the tendon. A suture is passed through the tendon and the tendon is advanced through the flexor tendon pulley system to the distal phalanx. This often requires dilation of the pulley system. A pediatric feeding tube may be helpful in passing the tendon under the pulleys. Attempts should be made to preserve the A2 and A4 pulleys. Overadvance- ment of the tendon should be avoided to prevent quadriga. In type I injuries, the distal end of the tendon will be avascular as a result of the disrupted vincula and should be trimmed prior to reapprox- imation. In type II rupture, the vincula remain intact, but fibrosis may develop at the FDS chiasm, which may limit tendon gliding. The fibrotic end should be debrided in these cases. ● ● Dorsal button technique ( Figure 35.5 ) ◆ ◆ The bone bed on the distal phalanx should be prepared by removing any soft tissue, while still preserving the palmar plate to promote direct tendon-bone healing. Next, Keith needles are drilled into the distal phalangeal bone bed exiting through the mid portion of the nail plate and paired sutures are passed through the tendon and tied over a button on top of the nail plate via the Keith needles. ◆ ◆ Disadvantages—The pull-through button technique may lead to tendon-bone gapping due to the distance between the fixation point of the tendon-bone and the suture knot. This can also damage the nail plate, including deformity and nail fold necrosis, but these complications are rare. ● ● Suture anchor technique ◆ ◆ This technique has potential advantages of complete internaliza- tion of the suture anchor without disruption of the nail plate or