Robotic-assisted total knee arthroplasty results in decreased incidence of anterior femoral notching compared to posterior referenced instrumented total knee arthroplasty.

OBJECTIVE: Periprosthetic fracture (PPF) is an uncommon but devastating complication after total knee arthroplasty (TKA). Anterior femoral notching (AFN) is one of a perioperative risk factor for PPF. The main purpose of this study was to compare between the rates of anterior femoral notching (AFN) and supracondylar periprosthetic femoral fracture (sPPF) of manual TKA and robotic arm-assisted TKA (RATKA). Meanwhile, blood loss, transfusion rates, inflammatory responses, complications, early clinical and radiological outcomes were also assessed.

METHODS: This retrospective study included 330 patients (133 RATKA and 197 manual TKA). Differences in risks of inflammatory, blood loss, complications (periprosthetic fracture and periprosthetic joint infection), pre-operative and post-operative distal lateral femoral angle (LDFA), distal femoral width (DFW), prosthesis-distal femoral width (PDFW) ratio, AFN, femoral component flexion angle (FCFA), peri-operative and post-operative functional outcomes between the RATKA and manual TKA groups were compared.

RESULTS: The operation time and postoperative CRP level in the RATKA group was significantly longer and higher than that in the manual TKA group ( p < .001). However, there was no significant difference in postoperative WBC level ( p = .217), hemoglobin loss ( p = .362), postoperative drainage ( p = .836), and periprosthetic fracture ( p = 1.000). There was no significant difference in LDFA ( p > .05), DFW( p = .834), PDFW ratio ( p = .089) and FCFA ( p = .315) between the two groups, but the rate of AFN in the RATKA group was significantly lower than that in the manual TKA group ( p < .05). There was no significant difference in ROM between the two groups on POD3, POD 90 and 1 year ( p < .05), but the FJS-12 score in the RATKA group was higher than that in the manual TKA group on 1 year ( p = .001).

CONCLUSION: Robotic-assisted total knee arthroplasty can decrease the incidence of anterior femoral notching compared to posterior referenced instrumented total knee arthroplasty.