The irreducible knee-luxation after low-velocity trauma

Abstract

Aims and Objectives: Knee-luxations are severe and rare injuries. Within the last years there is an incline on low velocity trauma leading to a nee-luxation. The luxated knee should be reduced immediately to minimize collateral damage to soft-tissue structures, nerves, vessels, etc. Materials and Methods: We report about a 87-year old man who was brought to our emergency room after he fell out of his bed. He showed a to the lateral side luxated tibial-head, which could not be reduced in analog sedation. The foot pulses could be measured with the Doppler, the patient was under massive pain so we decided to perform an immediate operative intervention. Even under maximum relaxtion the knee stayed in medial luxation. Results: The open reposition showed the destruction of all medial structures including the subcutaneous fat. The medial condyle was completely uncovered. The sartorious fascia, the ruptured M. vastus medialis and fibres of the medial collateral ligament have been trapped in the medial tibial joint line. The reposition was made possible by incision of the sartorious fascia. The tibially ruptured acl was refixated in a modified canula technique, the medial structures were adapted with sutures and additionally stabilized with ligament bracing for the medial collateral ligament. Postoperatively, the knee was immobilized in an external fixation for two week. Afterward we started with functional rehabilitation. The postoperatively obtained CT-angiography showed now traumatic vascular damage. This case is completely foto-documented. Conclusion: The irreducible knee-luxations are rare complications. So far there are 4 cases published. In all cases there has been an interposition of the musculus vastus medialis an the surrounding structures. An immediate open intervenvtion to reposition the knee has to be performed to avoid severe damage to. Especially the elderly patient benefits from a single-staged procedure to reconstruct the ruptured ligaments. To realize the best outcome early functional rehabilitation under close supervision of the surgeon is necessary.