Primary Total Knee Arthroplasty Using a Cementless Highly Porous Titanium Tibial Baseplate in Patients Under the Age of 50: An Average 7.6-year Follow-up

Background Younger and more active patients undergoing primary cemented total knee arthroplasty (TKA) have demonstrated increased failure incidence due to multiple factors including aseptic loosening. The purpose of this study was to evaluate results of cementless TKA using a highly porous cementless tibial baseplate in patients aged ≤50 years. Methods This was a retrospective study of 150 consecutive cementless TKAs in patients aged ≤50 years using the same implant design. Twenty-nine patients were lost-to-follow-up (19.3%), leaving 121 TKAs in 98 patients with minimum 5-year follow-up. There were 41 men and 80 women with mean age of 45.8 years (range, 32-50), mean BMI of 37.5 kg/m 2 (range, 19.3-64.1), and mean follow-up of 7.6 years (range, 4.7-10.9). Clinical outcomes, complications, and patient-reported outcome measures were reviewed. Results There were 11 (9.1%) revisions: 5 (4.1%) for instability, 4 (3.3%) for dissociation of the metal-backed patella from the polyethylene, and 2 for unexplained pain elsewhere. Knee Society function and knee scores improved from means of 46.6 and 39.3 preoperatively to 79.9 and 83.3 postoperatively, respectively ( P < .001). Survivorship with aseptic loosening as the endpoint was 100% at 11.5 years and 87.7% due to all-cause revision. Conclusions Cementless TKA utilizing a highly porous baseplate in patients aged ≤50 years with mean 7.6-year follow-up demonstrated excellent survivorship with no revisions due to aseptic loosening. Results of this study using a cementless highly porous tibial baseplate with the advantage of biological fixation appear promising.