Evaluation of the safety and efficacy of the fully automated active robotic system in robotic assisted total knee arthroplasty

Abstract

Background: Use of semi-active and active robotic system for performing Total Knee Arthroplasty (TKA) is increasing. The novel fully automated active robotic system performs milling of the bone surfaces with a high speed burr. The aim of the current study was to assess the safety and efficacy of the system in robotic assisted TKA (RA-TKA).

Materials and methods: A single center clinical trial was conducted following 30 knees undergoing active RA-TKA for 6 months. Inclusion criteria were patients undergoing RA-TKA for end stage arthritis. Patients undergoing conventional TKA and revision TKA were excluded from the study. Sample size was estimated to be 28 patients with α error of 0.05 and β error of 0.2 with power of study being 80. A pre-defined list of RA-TKA adverse events was employed to study the safety of the system. Efficacy was judged by comparing the planned versus achieved Implant size, alignment and limb alignment on post-operative radiographs. The post-operative clinical evaluation was done by an independent observer who was not part of the operating team. The primary safety and efficacy hypothesis was tested using a one sided Exact binomial test. The p value < 0.05 was considered significant.

Results: Pre-defined adverse events did not occur in any of the 30 RA-TKA (statistically significant p value < 0.001). The implant size accuracy was 100% (30 out of 30 knees) for femoral component and 96.67% (29 out of 30 knees) for tibial component (statistically significant, Chi-squared test, p value 0.0105 and 0.0461 respectively). The implant position and limb alignment was accurate in 100% of patients (p value < 0.001).

Conclusion: Early experience of the use of fully automated active robotic system in TKA shows that it is safe and also is effective in achieving accurate implant size and implant/limb alignment.

Keywords: Efficacy; Fully automated; Robotic assisted; Safety; Total knee arthroplasty.

Fig. 1

Pre-Operative 3D CT Scan templating and planning of the RA-TKA.

Fig. 2

The Femur and Tibia points being registered in the computer.

Fig. 3

Fully automatic robotic arm performing distal femur and proximal tibia bone cuts.

Fig. 4

Pre- Operative and Post-Operative X-Ray and Intra-operative measurement estimation.

Fig. 5

Pre -operative and post- operative X-Ray.