ObjectiveTo explore the short-term effectiveness of domestic robot-assisted total knee arthroplasty (RATKA) conducted by a prospective randomized controlled trial.MethodsPatients who were scheduled for primary unilateral TKA between October 2020 and December 2020 were eligible in this randomized controlled trial. According to the random number table method, they were allocated to the traditional TKA group and the RATKA group [application of the Yuanhua robotic-assisted TKA (YUANHUA-TKA) system during operation]. A total of 63 patients met the selection criteria were enrolled in the study, of which 3 cases voluntarily withdrew from the trial. And finally 60 cases were enrolled for analysis; of which 28 cases were in the RATKA group and 32 cases were in the traditional TKA group. There was no significant difference in gender, age, body mass index, American Society of Anesthesiologists (ASA) classification, duration of osteoarthritis, surgical side, and preoperative knee visual analogue scale (VAS) resting and motion scores, joint range of motion (ROM), Knee Society Score (KSS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC) pain, stiffness, and function scores, hip-knee-ankle angle (HKA) deviation (P>0.05). The operation time and intraoperative blood loss of the two groups were recorded. Knee joint VAS resting and motion scores, ROM, KSS scores, and WOMAC pain, stiffness, and function scores were used to evaluate the knee joint function and pain. Gait analysis (flexion and extension angle) was conducted at 3 months after operation. The full length X-ray films of lower limbs and anteroposterior and lateral X-ray films of knee joint were taken. The HKA deviation, lateral tibia component (LTC), frontal femoral component (FFC), frontal tibia component (FTC), and lateral femoral component (LFC) measured on the X-ray films were used to evaluat the lower limb alignment and prosthesis position.ResultsThe operations of the two groups completed successfully; the incisions healed by first intention after operation, and no complications related to the operation occurred. The operation time of the RATKA group was significantly longer than that of the traditional TKA group (t=12.253, P=0.001), and there was no significant difference in intraoperative blood loss between the two groups (t=3.382, P=0.071). All patients were followed up 3 months. At 3 months after operation, the knee joint VAS resting and motion scores, ROM, KSS scores, and WOMAC pain, stiffness, and function scores improved significantly when compared with preoperatively in the two groups (P<0.05); there was no significant difference of pre- and post-operative indicators between the two groups (P>0.05). The gait analysis showed that the flexion and extension angle in the RATKA group was significantly bigger than that in the traditional TKA group (t=9.469, P=0.003). X-ray films reexamination at 3 months after operation showed that the prostheses in the two groups were in good positions, and there was no adverse events such as prosthesis loosening or sinking. There were significant differences in the HKA deviation between pre- and post-operation in the two groups (P<0.05), but the difference of pre- and post-operative HKA deviation between the two groups was not significant (t=1.254, P=0.267). There was no significant difference in FFC, FTC, and LFC between the two groups (P>0.05); the LTC was significantly smaller in the RATKA group than in the traditional TKA group (t=17.819, P=0.000), which was closer to the ideal value.ConclusionYUANHUA-TKA system can improve the accuracy of osteotomy and the prosthesis placement as well as the lower limb alignment. Its short-term effectiveness can be promised, but long-term effectiveness needs to be further studied.
Lower limb alignment and soft tissue balance are important factors affecting patient satisfaction, clinical functional outcome, and prosthetic long-term survival rate after total knee arthroplasty (TKA). Robot-assisted TKA (rTKA) has the advantages of achieving precise osteotomy and soft tissue balance. However, rTKA under the guidance of classic mechanical alignment principles does not significantly improve the functional outcome after operation. The new TKA alignment principles, such as kinematic alignment (KA) and functional alignment (FA), can better consider the patient’s own knee joint morphology and kinematic characteristics, which may help improve the clinical results of TKA. With the help of more objective and accurate soft tissue balance assessment tool such as pressure sensors, KA and FA have been proven to better achieve soft tissue balance. rTKA can achieve non-neutral alignment goals such as KA or FA more accurately and reproducibly. The use of these lower limb alignment and soft tissue balancing strategies will be expected to further increase the patients’ satisfaction rate after rTKA.