A Selective arthroplasty algorithm contributes to clinical outcome and patient satisfaction in patients with osteoarthritis of the knee

AIMS AND OBJECTIVES: The purpose was to evaluate the clinical outcomes and patient satisfaction of patients with knee osteoarthritis treated within a selective arthroplasty algorithm, using focal metal implants (FMI), unicompartmental (UKA), patellofemoral (PFA), bicompartimental (BKA) and total knee arthroplasty (TKA) in a single center. MATERIALS AND METHODS: This is a prospective study analyzing a consecutive series of 613 patients treated by two surgeons in a single center. In 283 men and 330 women either partial or total knee replacement were performed. Their mean age at surgery was 63±6,85 years and mean BMI 29,55±5,00 kg/m2. 357 UKA, 178 TKA, 30 PFA, 23 BKA and 25 FMI were performed. Implants were cemented or cementless (UKA) and made of cobalt chrome in partial knee and zirconium oxide in total knee replacement. Demographics and patient reported outcomes (VAS, KOOS, Oxford Knee Score (OKS) and Knee Society Score (KSS Expectations and satisfaction)) were collected preoperatively and 3,6 and 12 months postoperatively. A total of 442 of 457 eligible patients (Compliance = 96,7%) have thus far completed the 12 months follow-up time point. RESULTS: All mean KOOS, OKS, KSS and VAS scores improved significantly 1 year after surgery (p<0.05). Mean preoperative aggregated KOOS improved from 49.8±13,3 to 74,8±16.9 in UKA, from 43,9±13,3 to 65,2±12,4 in PFA, from 46.6±13,1 to 73,8±14,4 in TKA, from 45,2±11,2 to 73,0±9,8 in BKA and 40.9 ± 23.0 to 63.2 in FMI (p<0.05). Mean preoperative aggregated OKS improved from 25,3±7,6 to 38,7±8,4 in UKA, from 22,9±7,6 to 33,3±8,6 in PFA, from 23.3±7.3 to 37,5±7.7 in TKA, from 22,0±7,5 to 39,0±4.0 in BKA and from 22.9 ± 10.0 to 33.4 ± 11.3 in FMI (p<0.05). The mean pain level VAS decreased from pre-treatment to 12 months after surgery in UKA from 5.6 to 1.6, in PFA from 6.2 to 2.8, in TKA from 6.2 to 1.7, in BKA from 6.8 to 1.6 and VAS 5.5 to 2.4. The Mean KSS Expectation/Satisfaction improved at 1 y FU in UKA in expectation 13.7 ± 1.6 and mean KSS satisfaction: 31.1 ± 8.4, in FMI in expectation: 13.5 ± 1.6 and mean KSS satisfaction 26.0 ± 11.4 , in TKA: expectation 13.5 ± 1.8 and mean KSS satisfaction 30.0 ± 7.1, in PFA: expectation 13.7 ± 1.7 and mean KSS satisfaction 26.4 ± 9.2 and BKA: expectation 13.6 ± 1.9 and mean KSS satisfaction 31.2 ± 4.2. Two patients (0.4%) underwent revision (at 3 month for inlay dislocation (UKA) and at 12 Month for desease progression (FMI)). CONCLUSION: This study shows excellent clinical results and patient satisfaction of patients treated within a selective arthroplasty algorithm. Adherence to strict indications for partial as well as for total knee replacement will lead to a comparable significant improvement of patient reported outcomes, patient satisfaction and a low revision rate one year postoperatively.