Efficacy of the newly designed "SkyWalker" robot compared to the MAKO robotic system in primary total knee arthroplasty: a one-year follow-up study.

PURPOSE: Robot-assisted surgical systems for performing total knee arthroplasty (TKA) have gained significant attention. This study was designed to compare the surgical outcomes in primary TKA surgery between the recently developed "SkyWalker" robot system and the more commonly used MAKO robot. METHODS: A total of 75 patients undergoing primary TKA surgery by the same surgical team were included in this study, with 30 patients in the "SkyWalker" group and 45 patients in the "MAKO" group. We documented the osteotomy plan for both robotic systems. The lower limb alignment angles were evaluated by postoperative radiographic assessment. The operation time, estimated blood loss, postoperative hospital stays, and changes in laboratory indexes were collected during hospitalization. In addition, a comparative evaluation of knee functional assessments and complications was conducted during six month and one year follow-ups. RESULTS: There were no significant differences between the two groups in terms of the accuracy of restoring lower limb alignment, estimated blood loss, or operation time. The knee function assessments at six months and one year postoperatively were similar in both groups. Except for day three after surgery, the level of interleukin-6 (IL-6) and the change in IL-6 (∆IL-6) from preoperative baseline were higher in the "SkyWalker" group than in the MAKO group (median: 20.53 vs. 14.17, P=0.050 and median: 17.30 vs. 10.09, P=0.042, respectively). Additionally, one patient from the MAKO group underwent revision surgery at nine months postoperatively due to ongoing periprosthetic discomfort. CONCLUSIONS: The newly developed "SkyWalker" robot showed comparable efficacy to the MAKO robot in terms of lower limb alignment accuracy and postoperative six month and one year follow-up of clinically assessed resumption of knee function.

Sagittal Alignment in Total Knee Arthroplasty: Are There Any Discrepancies Between Robotic-Assisted and Manual Axis Orientation?

BACKGROUND: Sagittal alignment determines the extension and flexion of knee prostheses in total knee arthroplasty (TKA). The definition of the sagittal axes may be different between the Mako TKA system (Stryker) and the conventional manual intramedullary approach. Whether there is any discrepancy between the 2 approaches has not been well studied. METHODS: We retrospectively analyzed 60 full-length computed tomographic (CT) scans of the lower extremities of 54 patients. The femur and tibia were modeled by using Mimics (Materialise). The Mako mechanical axes were determined according to the Mako TKA Surgical Guide. The manual intramedullary axes were determined according to the central axis of the tibial proximal and femoral distal medullary cavities. The femoral, tibial, and combined angular discrepancies were measured in the sagittal plane. RESULTS: On the femoral side, the Mako mechanical axis was more likely to be located in an extended position relative to the manual intramedullary axis (56 of 60 knees). The median angular discrepancy was 2.46° (interquartile range [IQR], 1.56° to 3.43° [range, -1.06° to 5.24°]). On the tibial side, the Mako mechanical axis was likely to be located in a flexed position relative to the manual intramedullary axis (57 of 60 knees). The median angular discrepancy was 2.40° (IQR, 1.87° to 2.84° [range, -0.79° to 4.20°]). The angular discrepancy of the femoral-tibial sagittal angle was 4.63° (IQR, 3.71° to 5.64° [range, 1.20° to 9.02°]). CONCLUSIONS: Compared with manual TKA, the Mako system is more likely to result in a decreased posterior tibial slope and extension of the femoral prosthesis. It may also influence the evaluation of lower-extremity extension and flexion. When using the Mako system, special attention should be given to these discrepancies. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Internal fixation and unicompartmental knee arthroplasty for an elderly patient with patellar fracture and anteromedial osteoarthritis: A case report.

BACKGROUND: Open reduction and internal fixation (ORIF) is the traditional surgical treatment for patellar fractures, and unicompartmental knee arthroplasty (UKA), especially Oxford UKA, has been increasingly used in patients with medial knee osteoarthritis (OA). However, the process of choosing treatment for patients with both patellar fractures and anteromedial knee OA remains unclear. We present the case of a patient with a patellar fracture and anteromedial OA. CASE SUMMARY: We present the case of a 72-year-old woman with a history of bilateral medial compartment OA of the knees and a right Oxford UKA. She also experienced a recent left patellar fracture. ORIF and Oxford UKA were performed in a single stage. The patient showed excellent postoperative clinical results. CONCLUSION: ORIF and Oxford UKA can be performed simultaneously for patients with patellar fracture and anteromedial OA on the same knee.