Abstract
OBJECTIVE: Computer-assisted surgery (CAS) and patient-specific instrumentation (PSI) are digital techniques to improve the accuracy of implant positioning in total knee arthroplasty (TKA), but their effects on clinical outcomes are still in dispute. The objective of this trial is to evaluate the efficacy and safety of CAS and PSI compared to conventional instrumentation (CI) in TKA. METHODS: A prospective randomized controlled trial was conducted. A total of 135 patients undergoing TKA were randomized into CAS group, PSI group and CI group with 45 patients in each group. Primary outcome is the coronal mechanical axis of lower extremity. Secondary outcomes include Femoral Rotation Angle (FRA) of the femoral prosthesis, operation time, perioperative blood loss, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Forgotten Joint Score (FJS) and complications. RESULTS: Outliers of Hip-Knee-Ankle angle (HKA) were 24.4% in CI group, 17.8% in CAS group and 31.1% in PSI group respectively, and there was no significant difference among these 3 groups (P > 0.05). Outliers of FRA were 13.3% in CI group, 26.7% in CAS group and 11.1% in PSI group respectively with no significant difference (P > 0.05). Operation time was (66.67 ± 12.85)min, (81.67 ± 12.31)min and (52.78 ± 8.62)min in CI, CAS and PSI group. Operation time in CI was longer than PSI and shorter than CAS with significant difference (P < 0.01). There was no significant difference in comparison of blood loss, transfusion rate, postoperative WOMAC and FJS (P > 0.05). CONCLUSION: CAS and PSI, compared with CI, did not significantly improve clinical outcomes including lower limb alignment, rotation of femoral prosthesis, blood loss, transfusion rate, and function scores. However, CAS was associated with prolonged operation time, whereas PSI resulted in a reduced operation time. LEVEL OF EVIDENCE: Level II. TRIAL REGISTRATION: ChiCTR-INR-17,012,881 (registration date: 03/10/2017).