Rotating-platform deep-dish total knee arthroplasty with restricted kinematic alignment: Five-year clinical and functional outcomes

Introduction: Total knee arthroplasty (TKA) utilizing deep-dish tibial inserts has gained interest due to its high congruency and enhanced stability. However, due to the advent of more personalized alignment philosophies, the combination of a rotating-platform deep-dish TKA design with restricted kinematic alignment (rKA) might improve patient satisfaction. Therefore, this study evaluated the five-year clinical and functional outcomes of rKA with a deep-dish TKA design. Methods: A retrospective analysis was conducted on patients who underwent primary TKA with a rotating-platform deep-dish design and rKA. Of 143 eligible patients, 123 completed five-year follow-up. Clinical and radiographic assessments included the five-year postoperative results: Knee Society Score (KSS), patient satisfaction, range of motion, coronal limb and implant alignment, postoperative complications and implant survivorship. Statistical analyses compared preoperative and postoperative outcomes with paired analyses. Results: Median KSS Knee and Function scores significantly improved from 70 (IQR 5) and 60 (IQR 26) preoperatively to 90 (IQR 20) and 93 (IQR 21) postoperatively (p < 0.001). Postoperative coronal alignment in this study encompassed a hip-knee-ankle angle was 178.1° ± 3.5, a Lateral Distal Femoral Angle of 89.9° ± 2.6, and a Medial Proximal Tibial Angle of 88.6° ± 2.2. At five years, 94% of patients were either satisfied or very satisfied. The revision-free survival rate was 98%. Periprosthetic joint infection and arthrofibrosis were the most common complications (1.6% for both groups separately), followed by aseptic loosening of a cementless femoral component (0.8%) and patellar dislocation (0.8%). Discussion: Rotating-platform deep-dish TKA with restricted kinematic alignment results in excellent functional outcomes, high patient satisfaction, and low complication rates at five-year follow-up. These findings support its viability as a surgical strategy, though long-term studies are warranted to assess implant durability and survivorship beyond 10 years.