With the development of surgical technique and instrument, the number of spinal surgery, especially spinal instrumen- tation, is increasing. In addition, the spinal surgeries in high risk patients, such as elderly patients, diabetes mellitus, immune deficiency patients, and obesity, are also increasing. Post-operative wound infection after spinal instrumen- tation is the major complication in such patients, which may adversely influence the surgical results, which are pro- longed the hospital day and antibiotics use, non-union, and post-operative back pain. There have been many controversies about the treatment of post-operative wound infection after spinal instrumen- tation. Early detection of wound infection is the most important. So we should observe the wound carefully. If there were redness, local heating and swelling, the authors always check the WBC count with differentiation, ESR and CRP and we changed the antibiotics. However, if there were no changes or further elevation in these chemical parameters and generalized sign of infection such as fever, the authors did MRI or CT scan for the diagnosis of abscess formation. The spinal instrument may act as a foreign body. However, our principle of surgical treatment of wound infection is the maintenance of spinal instrumentation. At the time of revision surgery due to surgical wound infection, wide inci- sion and debridement of necrotic tissue is mandatory. As a final step of revision surgery, the authors always insert the irrigation catheters for post-operative closed continuous irrigation. Of course, the irrigation fluid should be mixed with the sensitive antibiotics and the patients should be injected with sensitive antibiotics. These closed continuous irrigation catheters were maintained about one week. Intravenous antibiotics were injected until normalization of CRP. After nor- malization of CRP, oral antibiotics were used and it may be continued until normalization of ESR. Among the 5235 patients who underwent a lumbar fusion with instruments from January 1, 1993 to December 31, 2003 in our institute, total 33(0.63%) patients had postoperative deep wound infection after spinal instrumentation. Among them, 25(76%) cases of post-operative wound infection after spinal instrumentation were treated with above closed continuous irrigation method. Of them, 18(72%) cases could be cured successfully. There were 7(28%) cases of recurrent infection, in which vertebral spondylitis developed in spite of revision surgery, closed continuous irrigation, and sensitive antibiotics. These 7(28%) patients should be removed the spinal instrument.
