Rapid Osteolysis and Loosening of Unicompartmantal Knee Prosthesis Due to Posterior Dislocation of the Polyethylene Insert

Abstract

Introduction: Unicondylar knee arthroplasty (UKA) is a treatment option for pure medial tibiofemoral osteoarthrosis. The most common complication of UKA is anterior or medial polyethylene dislocation. We report a rare complication (posterior fixed polyethylene dislocation) of UKA. Case: We present a case of 79-year-old man with bilateral medial compart man arthrosis underwent bilaterally medial UKA. He had posterior fixed intra-articular polyethylene dislocation which was missed by his first intervention. After three months of missed polyethylene dislocation the implants of UKA was totally loosen. Conclusion: Diagnostic delay of polyethylene dislocation may result to loosening of component and it will lead to revision of UKA to TKA, which is technically challenging then primer total knee arthroplasty. The most common early complication of UKA is polyethylene dislocation. This should not be forgotten in a painful UKA with locking or without locking. Ortho Surg Ortho Care Int J Copyright © Alauddin Kochai 2/3 How to cite this article: Alauddin K. Rapid Osteolysis and Loosening of Unicompartmantal Knee Prosthesis Due to Posterior Dislocation of the Polyethylene Insert. Ortho Surg Ortho Care Int J . 2(2). OOIJ.000532.2018. DOI: 10.31031/OOIJ.2018.02.000532 Volume 2 Issue 2 The patient was referred to department of chest diseases and department of anesthesiology for preoperative preparation and treatment of lung problems. The department of chest diseases didn’t allow for an elective operation. He had to continue medical treatment for his lung diseases. After one and a half month the department of chest diseases and anesthesiology allowed for operation. In AP graphy the femoral and tibial components were loosen (Figure 2). Revision of UKA to TKA planed. Previous incision and medial parapatellar approach for arthrotomy performed. All compartments of the knee were covered by metallizes. The tibial and femoral components were loose and were moving with flexion and extension of the knee. The polyethylene was fixed at the posterior of the knee. The tibia and femoral components easily removed. Polyethylene released from the posterior of the knee and removed. Femoral and tibia osteotomies for total knee arthroplasty performed. Total knee arthroplasty procedure successfully performed (Figure 3). At the first day after operation the patient began walking comfortably without any support. The patient was extern 4 days after operation with 0-120 degrees ROM of the knee.