Abstract
Aim
In surgeries on patients with advanced ligament instabilities or severe bone defects modern-generation of rotating hinged knee prostheses are one of the main options. The objective of our study is to evaluate the mid-term functional results and complications of several surgeries using this form of prosthesis.
Material and Method
The rotating hinged knee prosthesis (RHKP) was applied to 208 knees of 204 patients in primary surgeries between September 2009 and December 2017, the minimum followup was 15 months (mean, 65 months; range, 15–115 months). Of the total number of female patients there were 152 (74.5%), men − 52 (25.5%). The average age of the patients was 64,6 years (from 32 to 85). The main indications for using RHKP were severe varus deformity with flexion contracture in 107 knees (51,4%), severe valgus deformity (from 20 to 50 degrees) in 54 knees (26,0 %), severe ligamentous deficiencies in 24 knees (11,5%) and ankylosis in the flexion position in 23 cases (11,1%). Patients were evaluated clinically (Knee Society score) and radiographically (positions of components, signs of loosening, bone loss).
Results
The average Knee Society Knee Scores, and Knee Society Functional Scores were 27, and 18, respectively, before the surgery; and 86, and 77 in the final post-surgery follow-ups. In addition, the average range of motion increased from the pre-operative level of 46 to 104 degrees at the final evaluation. Four patients (2%) had various complications after the surgery : two patients had deep infection, in one case took place fracture of the hinge mechanism and in one - post-operative rupture of the patellar tendon.
Conclusions
Primary knee arthroplasty using RKHP can be successful in cases with advanced ligament instability or severe bone defects. Modern-generation of the kinematic rotating-hinge total knee prostheses allow to achieve in difficult primary cases the same consistently good results as commonly used constructions in standard situations.
