Abstract
PURPOSE: To evaluate the clinical and radiographic results of a novel partial unicondylar arthroplasty (PUCA) using a three-dimensional-printed (3DP) porous tantalum prosthesis for treating focal osteochondral defects (FOCD) of the femoral condyle, in comparison with unicompartmental knee arthroplasty (UKA). METHODS: This exploratory-retrospective matched-cohort consecutively enrolled study involved 17 patients: 8 in Group A (PUCA with 3DP porous tantalum prosthesis) from a larger trial and 9 in Group B (UKA), matched by age, gender, and BMI. Participants, aged 18-60, had femoral condylar FOCD with complete clinical and imaging data; exclusions included knee instability and incomplete data. Follow-ups were at 6 weeks, 3, 6, 12 months, and annually. The primary outcome was the Hospital for Special Surgery (HSS) knee score, with secondary outcomes including visual analogue scale (VAS), time to full-weight-bearing walking (FWBK), knee injury and osteoarthritis outcome score (KOOS), Lysholm scores and range of motion (ROM). Prosthesis stability and Kellgren-Lawrence (KL) grading were assessed via radiograph, and postoperative complications were compared. Statistical analyses included the Mann-Whitney U test, independent-samples t test, and Fisher's Exact test. RESULTS: All patients averaged 49.6 years old at surgery with a mean follow-up of 49.6 months. No demographic or complication differences were found between groups, and no revisions were needed. Preoperative scores were similar (P > 0.05). Postoperatively, Group A demonstrated significantly greater improvements in KL grades (1.5 ± 0.5 vs. 2.5 ± 0.5, P = 0.006), VAS (1.3 ± 0.5 vs. 2.5 ± 0.5, P = 0.002), HSS (92.3 ± 1.8 vs. 87.4 ± 1.6, P = 0.000), KOOS (90.9 ± 1.6 vs. 88.3 ± 1.9, P = 0.009), Lysholm (91.4 ± 2.4 vs. 88.5 ± 1.9, P = 0.019), and ROM (133.1° ± 6.5° vs. 115.6° ± 4.0°, P = 0.000), except for FWBK (4.9 ± 0.8 vs. 5.3 ± 0.5 weeks, P = 0.189). However, only the difference in ROM met the minimum clinically important difference. All postoperative scores, except for ROM and KL, showed statistically significant improvement compared with preoperative values in both groups radiographs at final follow-up showed stable prostheses in both groups with no signs of loosening. The statistical power for postoperative HSS was 1.0 (G*Power, effect size = 2.89). CONCLUSION: This initial study is the first to apply personalized PUCA with 3DP porous tantalum prostheses for FOCD, demonstrating promising early outcomes compared with UKA, such as delayed progression of osteoarthritis, effective pain relief, and improved knee function and quality of life. PUCA notably preserves more native tissue and adapts to individual defects, making it clinically feasible by offering a potentially better option for future FOCD management.