A high level of satisfaction after bicompartmental individualized knee arthroplasty with patient‐specific implants and instruments

Purpose Customized Individually Made (CIM) Bicompartmental Knee Arthroplasty (BKA) implants and three‐dimensional printed customized instruments are available to fit to each patient’s unique anatomy, medial or lateral with patellofemoral. This study aimed to evaluate the clinical outcomes after CIM‐BKA. Methods Fifty‐five patients [59 knees; average age, 51 years; standard deviation (SD), 6.8; range 37–65 years] who underwent CIM‐BKA were evaluated over an average of 3.8‐year follow‐up (SD 1.6; range 1–6 years). Forty‐one knees underwent BKA combined medial and patellofemoral replacement (BKA‐MP) and 18 knees underwent BKA combined lateral with patellofemoral replacement (BKA‐LP). Survival rates, the modified Cincinnati Knee Rating Scale, WOMAC, VAS, SF‐36, a satisfaction survey, and radiographic evaluation were used to evaluate outcomes. Results Overall, survival rates were 98% and 92% at 2 and 5 years, respectively. Of 56 knees (95%) that did not fail, all patient‐reported functional scores significantly improved post‐operatively ( P  < 0.01), regardless of the previous surgeries, with a high level of satisfaction (51/56 knees, 91%). Radiographically, all the femoral components fit perfectly and 56 knees (95%) of the tibial components fit with less than 2 mm of undercoverage or overhang. Three knees (5%) required the conversion to TKA and 17 knees (29%) required subsequent surgical procedures, of which multiply operated knees had higher rate than virgin knee [14/40 (35%) vs. 3/16 (19%)]. Conclusion CIM‐BKA allowed precise fit of the components and provided a significant improvement post‐operatively with a high level of satisfaction over short‐ to mid‐term follow‐up. This novel CIM‐BKA is resurfacing, and does not require 10‐mm faceted cuts, being only 3‐mm‐thick, which preserves bone stock for the future. It may be a promising option for relatively young active patients with bicompartmental osteoarthritis with a longer term follow‐up being necessary. Level of evidence IV.