Bicompartmental Knee Arthroplasty (BKA) in comparison to unicompartmental (UKA), Patellofemoral (PFA) ans total knee arthroplasty (TKA) – Early Clinical Results

Abstract

Aims and Objectives: The purpose was to evaluate the clinical outcomes of patients with knee osteoarthritis treated with bicompartmental arthroplasty (BKA) in comparison to unicompartmental (UKA), patellofemoral (PFA) and total knee arthroplasty (TKA) in a single center. Materials and Methods: This is a prospective study analyzing a consecutive series of 396 patients from two surgeons in a single center. In 191 men and 205 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. In 238 patients UKA, in 125 TKA, in 21 PFA and in 11 patients BKA was performed. Implants were cemented 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)) were collected preoperatively and 3,6 and 12 months postoperatively. A total of 202 patients have thus far completed the 12 months follow-up time point. Results: All mean KOOS and OKS scores improved significantly 1 year after surgery (p<0.05). Mean preoperative aggregated KOOS improved from 49,0±14,1 to 74,3±17,8 in UKA, from 44,1±12,9 to 67,5±9,4 in PFA, from 46,1±15,1 to 71,0±14,8 in TKA and from 45,7±13,8 to 72,6±9,7 in BKA (p<0.05). Mean preoperative aggregated OKS improved from 25,1±7,6) to 38,5±9,7 in UKA, from 23,0±7,6 to 36,8±3,8 in PFA, from 23,4±8,2 to 37,3±8,1 in TKA and from 22,9±9,6 to 37,0±1,5 in BKA (p<0.05). The mean pain level (VAS)decreased from pre-treatment to 12 months after surgery in UKA from 5,5 to 1,6, in PFA from 6,1 to 2,5, in TKA from 6,0 to 1,9 and in BKA from 6,6 to 2,6. One patient (0.4%) underwent revision (at 3 month for inlay dislocation). Conclusion: This study shows excellent early clinical results of patients treated with unicompartmental, bicompartmental and total knee arthroplasty. Adherence to strict indications lead to a significant improvement of patient reported outcomes and a low revision rate one year postoperatively. The reported results for BKA are comparable to those of patients treated with unicompartmental arthroplasty. We conclude that bicompartmental arthroplasty is a safe and reliable surgery for patients with bicompartmental osteoarthritis.