Knee Joint Dislocation Complicated by Tabes Dorsalis Requiring Open Reduction: A Case Report

Abstract

herein report a case of knee dislocation with an unusual clinical course in which closed reduction was difficult due to the patient's past illness. Case ReportA 78-year-old man was injured in a fall while wheeling his bicycle on a snowy road. Although his right knee joint was deformed, he left it untreated for seven days, but finally attended the outpatient department of our hospital at the suggestion of his family on day 8 after the injury. At the first examination, his right knee joint was swollen and contracted in a slight flexion/varus/lateral rotation position. The femur protruded as a result of the deformation, and the skin of the proximomedial region of the knee showed ischemic change due to compression (Figures 1 and 2). The right dorsalis pedis pulse was weak but palpable. Plain X-ray films showed that the patella was outwardly displaced, and the tibia was displaced posterolaterally to the femur. Based on these findings, we made a diagnosis of traumatic knee joint dislocation (Figures 3 and 4).He had a history of quaternary neurosyphilis and had been treated with high doses of penicillin prior to the current visit, with sequelae of tabes dorsalis and dementia. Before the injury, imperception and gait disturbance due to spinal ataxia had been observed in the patient.Under fluoroscopic guidance, we tried several closed reduction methods such as anterior tibial drawer in the knee flexed position, lower limb traction and application of anterior pressure to the patella, but failed to reposition the knee. Subsequently, we tried to perform closed reduction under general anesthesia. During repositioning, the skin with ischemic change was lacerated and the articular surface of the medial femoral condyle was exposed, creating an open wound on the knee (Figure 5). Consequently, we changed the procedure to open reduction. AbstractA 78-year-old man sustained right knee dislocation in a fall. His pain was diminished on account of his past history of tabes dorsalis due to neurosyphilis, resulting in delayed hospital attendance for a week. The injury was posterolateral rotatory dislocation of the knee. Since closed reduction was not possible, open reduction was performed. Most cases of knee joint dislocation are easy to reduce. However, it is difficult to conduct closed reduction in this type of dislocation, because the joint capsule and medial collateral ligaments are torn by the medial femoral condyle. It is important to recognize that some types of dislocation of the knee are difficult to reduce.