65 Painful Finger after Bony Nonunion
65.1 Patient History Leading to the Specific Problem
A 25-year-old man presents with painful bony nonunion of the middle phalanx of his right middle finger. He incurred amputation of the finger 10 weeks before by trauma with electric-powered scissors. Original surgery included replantation via suture of the deep flexor tendon, extensor tendon, and primary end-to-end suture of both neurovascular bundles and of two dorsal veins. Osteosynthesis was performed by diagonal Kirschner’s wires (K-wires) with additive intraosseous suture. The distal interphalangeal joint was transfixed because of ligament instability. ▶Fig. 65.1 shows initial findings and results of the original surgery. Absence of bony healing was diagnosed in plain radiological follow-up controls. ▶Fig. 65.2 shows radiological findings 10 weeks after replantation.
Fig. 65.1 Exemplary case of a single-finger replantation. (a–c) Preoperative findings. (d, e) Intraoperative findings. (f, g) Early postoperative clinical result.
65.2 Anatomic Description of the Patient’s Current Status
In the presented case, replantation surgery was performed without significant intraoperative complications. Postoperative blood supply of the finger was regular; wound healing was primary. However, the lateral X-ray raises suspicion that the axial K-wire did not sufficiently stabilize the proximal fragment. In further course, consolidation of the phalanx was not adequate. Nevertheless, active physical therapy was started after 6 weeks of immobilization with only guided and passive exercises to prevent further stiffening of the fingers. Active tendon function was present upon careful examination. Yet, the patient felt pain and had the feeling of instability of the affected finger. Further course of rehabilitation was ineffective in the face of the radiologically confirmed bony nonunion. Therefore, the indication for surgical revision was confirmed.
65.3 Recommended Solution to the Problem
Localized pain was caused by bony nonunion; thus, the clinical problem could be solved by bony revision in this case. In digital replantation, the 6-month period is not always a prerequisite for establishing the diagnosis of nonunion and for the decision in favor of a revision surgery. This holds especially true if biomechanical factors such as inadequate stabilization and biological factors such as suboptimal perfusion and excessive soft-tissue trauma prohibit bony healing. In the presented case, the early date of revision was chosen because painful instability of the finger disturbed physical therapy and postoperative recovery. Due to the significant risk for joint or even finger stiffness as a consequence of prolonged immobilization, mobility of the unaffected fingers has to be preserved at all costs. Effective physical therapy and early mobilization are essential for this purpose.
One should realize that especially a replantation with limited postoperative perfusion needs a stable fixation to prevent nonunion. Suitable methods are after primary shortening of the bone, shortened arthrodesis, osteosynthesis using K-wires, tension band wiring, or internal plate fixation. Of course, replantation is an individual situation every time, and not all these principles can be always implemented in favor of primary finger rescue. Therefore, the hand surgeon should be prepared for nonunion revision.
In the presented case, revision was performed by stable plate fixation and a cancellous bone graft from distal radius with moderate shortening of the bone and resection of avital bone and scar tissue. Because of preservation of venous perfusion and because of the mostly sclerotic soft tissue, length of the finger cannot always be restored. Corticocancellous bone grafting from iliac crest is only indicated if a larger gap results after removal of all fibrous tissue and resection of the affected bone. We recommend a dorsal approach. It must be emphasized that replanted tissue in finger replantation does not always randomize steadily after a certain time, so not only the palmar arteries but also the dorsal veins should be identified and preserved.
65.3.1 Recommended Solution to the Problem
• Replantation demands stable osteosynthesis. Often, a primary shortening of the bone is suitable. This may prevent nonunion.
• If a revision of bony nonunion is indicated, we recommend a dorsal approach.
• The dorsal veins should be identified and conserved during the procedure.
• Bone should be carefully debrided by moderate shortening and by removal of all fibrous tissue. Bone grafting from the distal radius is mostly adequate. Osteosynthesis should be performed by mechanically stable methods like internal locking plate fixation if the quality of skin and soft tissues is adequate. In selected cases, local flaps might be required for stabile defect coverage.