Mid-term results of rotating hinged knee prosthesis

Aim: In surgeries on patients with advanced ligament instabilities or severe bone defects rotating hinged knee prostheses are one of a limited number of appropriate options. The objective of our study is to evaluate the mid-term functional results and complications of several surgeries using this form of prothesis. Material and Method: The rotating hinged knee prosthesis (RHKP) was applied to 23 knees of 19 patients in primary or revision surgeries at our instution between February 2009 and December 2011. Following their operations,patients underwent several retrospective evaluations to assess surgical success. The average follow-up period for the patients was 54 months. The average age of the patients at their last follow-up was 75. Results: The average Special Surgery Knee Scores,Knee Society Knee Scores,and Knee Society Functional Scores were 44,27,and 18,respectively,before the surgery; and 83,92,and 70 in the final post-surgery follow-ups. In addition,the average range of motion increased from the pre-operative level of 76 to 101 degrees at the final evaluation. Two patients had per-operative rupture of the patellar tendon,and four patients had various complications after the surgery,including periprosthetic fracture,deep infection,aseptic loosening,and patellofemoral instability. Discussion: Primary or revision knee arthroplasty using RKHP can be successful in cases with advanced ligament instability or severe bone defects; however,increased complication rates should be kept in mind.