Short-term Clinical and Functional Outcomes of Deep-dish Congruent Tibial Polyethylene Component in Primary Total Knee Arthroplasty

Background: Total knee arthroplasty (TKA) is the definitive solution for advanced knee osteoarthritis (OA). A key variable in TKA is implant design, particularly regarding posterior cruciate ligament (PCL) management. Deep-dish congruent tibial polyethylene inserts offer a design alternative to conventional cruciate-retaining (CR) and posterior-stabilised (PS) implants, providing posterior stability without femoral bone resection. Methods: A prospective observational study was conducted involving 42 patients undergoing primary TKA with PCL-sacrificing and deep-dish congruent tibial polyethylene implants at a tertiary care centre. Preoperative and postoperative assessments were done using the Oxford Knee Score (OKS) and Knee Society Score (KSS) at 3–6 months. Results: The mean OKS improved from 15.7 ± 4.2 preoperatively to 37.9 ± 4.6 at 3 months and 40.3 ± 3.8 at 6 months and 41.3 ± 4.7 at the 1-year follow-up. The KSS pain component rose from 38.8 ± 11.5 to 79 ± 4.4 and the function score increased from 36.7 ± 23.4 to 82.6 ± 12.3 by the sixth postoperative month. At the final 1-year follow-up, the overall KSS improved from 41.6 ± 7.8 to 86.9 ± 6.2. Range of motion (ROM) improved significantly from 92.3 ± 8.5° preoperatively to 118.4 ± 9.2°, with no fixed flexion deformity observed. Statistical analysis showed highly significant improvements across all outcome measures ( P < .001). Conclusions: Deep-dish congruent polyethylene inserts in TKA offer excellent early functional and clinical results. By providing posterior stability while preserving bone, this design represents an optimal balance between CR and PS philosophies and may be especially suitable for elderly patients with deficient PCL.