PURPOSE: To evaluate the causes and modes of complications after unicompartmental knee arthroplasty (UKA) in Korean patients, and to identify the adaptability of mobile-bearing UKA for Korean patients by analyzing its complications. MATERIALS AND METHODS: Between January 2002 and December 2015, a total of 1,325 patients (1,560 cases) who underwent mobile-bearing medial UKA and were followed-up for more than 1 year were included in this study. We analyzed the complications of UKA retrospectively, and investigated the mode of complications, mean time to reoperation, and method of treatment. RESULTS: We observed a total of 101 complications (6.5%) after mobile-bearing UKA. The most prevalent complication was dislocation of mobile-bearing (n=52, 3.3%), accounting for more than half of the complications. Other complications include component loosening (n=16, 1.0%), progression of arthritis in lateral compartment (n=9, 0.6%), polyethylene wear and breakage (n=5, 0.3%), periprosthetic fracture (n=4, 0.3%), impingement (n=3, 0.2%), medial collateral ligament (MCL) injury (n=2, 0.1%), arthrofibrosis (n=1, 0.1%), unexplained pain (n=1, 0.1%) and infection (n=8, 0.5%). At a mean of 5.2 years post-UKA, complications occurred in our patients. The mean time interval from UKA to the development of mobile-bearing dislocation, component loosening, and progression of arthritis to the lateral compartment was a 4.3 years, 6.5 years, and 11.2 years, respectively. Complications were treated with a conversion to total knee arthroplasty in 68 cases, revision UKA in 1 case, and simple bearing change in 23 cases. Remaining complications were treated with arthroscopic management (n=3), MCL repair (n=2), open reduction and internal fixation (n=2), closed reduction and internal fixation (n=1), and manipulation (n=1). CONCLUSION: The incidence of mobile-bearing dislocation after mobile-bearing UKA was especially higher in Korean patients. However, the progression of arthritis in the lateral compartment and polyethylene wear were relatively lower compared with Western counterparts. Therefore, it is encouraged that Korean patients are provided with sufficient preparation for mobile-bearing dislocation and education prior to surgery when performing mobile-bearing UKA.
Arthritis ; Arthroplasty, Replacement, Knee* ; Collateral Ligaments ; Dislocations ; Education ; Humans ; Incidence ; Knee Joint ; Methods ; Osteoarthritis ; Periprosthetic Fractures ; Polyethylene ; Reoperation ; Retrospective Studies