[Infectious complications after arthroscopic replacement of the cruciate ligaments].

PURPOSE OF THE STUDY: Infection following replacement of the cruciate ligaments of the knee joint may result in not only graft failure but also complete destruction of the joint. The aim of this study was to report the authors' experience with the diagnosis and therapy of this, fortunately occasional, complication.

MATERIAL: In the period from October 1999 till June 2003, a total of 2372 arthroscopic operations of the knee joint were carried out; of these, 908 were cruciate ligament replacements. Three surgeons using the same technique were involved. An autologous graft taken from the ligamentum patellae and fixed with interference screws was used in 857 knees, and a graft derived from the tendon of the semitendinosus or the gracilis muscle, with "endobutton" fixation, was employed. Two kinds of inflammatory complications were recorded in the early post-operative period, i. e., infection of the articular cavity and infected subcutaneous hematoma at site of graft collection.

METHODS: When infection of the articular cavity was suspected because of severe pain, perspiration, motion restriction, articular exudate and increased temperature, arthrocentesis was performed and a sample of the fluid withdrawn was sent for cultivation; laboratory tests (blood counts, erythrocyte sedimentation rate, C-reactive protein) were carried out and antibiotic therapy was started. When there was no subsidence of signs within 24 h, revision surgery was carried out without waiting for the results of laboratory examination. Coagula from inside of the cavity were removed through a short incision on the lateral side of the suprapatellar recess and, after repeated thorough irrigation, a suction drain was inserted. Antibiotic therapy was administered parenterally. Infected subcutaneous hematoma, associated with edema, reddening and tension of the skin, pain, fluctuation and, in some cases, high temperature, was treated by disintegration of the wound, removal of the hematoma, debridement and thorough irrigation. After drain insertion, the wound was closed by suture. The development of infectious complications was assessed in relation to the risk factors described in the literature, namely, patient's age, operating room time and tourniquet application, previous infections of the upper respiratory or urinary tracts, previous surgery on the same joint and the season in which the operation was performed.

RESULTS: A total of 37 revision operations following replacement of the cruciate ligaments of the knee joint were carried out; of these, 29 involved the articular cavity. An infectious agent was found in six cases (0.7 % of the total number of cruciate ligament replacements). Eight knees were treated for hematoma in the wound at site of graft collection and, in seven of them, Staphylococcus aureus was isolated (0.8 % of the total number of crucial ligament replacements). For recurrent problems the distal fixation material had to be removed in two patients at 6 and 12 months, respectively. Afterwards the patients were free from symptoms. The only risk factor for the development of infection was found to be previous surgery on the same joint.

DISCUSSION: The authors prefer early revision surgery in the cases showing signs of developing infection in the articular cavity or hematoma in the wound after graft collection. Therefore the results of positive cultivation were fewer in comparison with other relevant reports. In revision surgery on the articular cavity, the authors made a 2-cm incision on the lateral side of the suprapatellar recess, which enabled them to wash out all coagula, in comparison to other authors who recommend irrigation with the use of arthroscopic apparatus only. The early intervention made it possible to keep all grafts in situ. The only factor associated with a higher occurrence of complications in our patients was a previous operation on the same joint.

CONCLUSIONS: On the basis of their experience with arthroscopic replacement of the cruciate ligaments, the authors recommend an active approach if the development of infectious complications is suspected. In our patients, no persisting sequelae were recorded.