The mid-term outcome of unicondylar knee arthroplasty for patients in mid-ages

Objective To evaluate the mid-term clinical outcome of unicondylar knee arthroplasty (UKA) in patients in mid-ages.Methods Nineteen cases (21 knees) with the age less than sixty were treated with UKA from April 2007 to January 2010 and were followed up.The range of motion (ROM),the Hospital for Special Surgery (HSS) knee score,the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index,Feller score,femur-tibia angle (FTA),width of lateral tibiofemoral joint space,visual analogue scale/score (VAS) and SF-36 scale were documented.Results All patients were followed up for 4 to 6.5 years (mean,5.2 years).The 5-years survival rate was 91.7％.One revision was performed due to polyethylene spacer frayed and prosthesis aseptic loosening.The polyethylene spacer was frayed in another patient,but there were no symptoms.The HSS was 88.1±6.8 at the final follow-up,which was 60.4±5.2 preoperatively.The WOMAC was 11.5±6.5 at the final follow-up,which was 42.9±5.9 preoperatively.The VAS was 1.1± 1.8 at the final follow-up,which was 6.6±0.7 preoperatively.The ROM was 121.2°± 11.1° at the final follow-up,which was 113.8°± 11.5° preoperatively.The Feller score was 25.2±6.6 at the final follow-up,which was 19.3±7.0 preoperatively.The FTA was 175.3°±2.4° at the final follow-up,which was 179.5°±3.8° preoperatively.The width of lateral tibiofemoral joint space was 6.7±0.6 mm at the final follow-up,which was 6.8±0.6 mm preoperatively.No deterioration of the laterally compartment or patellofemoral joint cartilage destruction happened.All the parameters of life quality were below the standard values excluding the BP,RE and PF.The exercise intensity was also decreased postoperatively.Conclusion The efficacy of UKA in mid-ages was satisfied and the 5-years survival rate was high. Key words: Arthroplasty, replacement, knee;  Treatment outcome;  Osteoarthritis