Iatrogenic bone and soft tissue trauma in robotic-arm assisted TKA compared to conventional jig-based TKA

Iatrogenic bone and soft tissue trauma in robotic-arm assisted total knee arthroplasty compared to conventional jig-based total knee arthroplasty: A prospective cohort study and validation of a new classification system, by Kayani et al. Arthroplasty (2018) in press, accepted manuscript.

Abstract:

Background
The objective of this study was to compare macroscopic bone and soft tissue injury between robotic-arm assisted total knee arthroplasty (RA-TKA) and conventional jig-based total knee arthroplasty (CJ-TKA), and create a validated classification system for reporting iatrogenic bone and periarticular soft tissue injury following TKA.

Methods
This study included 30 consecutive CJ-TKAs followed by 30 consecutive RA-TKAs performed by a single-surgeon. Intraoperative photographs of the femur, tibia, and periarticular soft tissues were taken prior to implantation of prostheses. Using these outcomes, a macroscopic soft tissue injury (MASTI) classification system was developed to grade iatrogenic soft tissue injuries. Inter- and intra-observer validity of the proposed classification system was assessed.

Results
Patients undergoing RA-TKA had reduced medial soft tissue injury in both passively correctible (p<0.05) and non-correctible varus deformities (p<0.05); more pristine femoral (p<0.05) and tibial (p<0.05) bone resection cuts; and improved MASTI scores compared to CJ-TKA (p<0.05). There was high inter-observer (ICC 0.92 [95% CI: 0.88-0.96], p<0.05) and intra-observer agreement (ICC 0.94 [95% CI: 0.92- 0.97], p<0.05) of the proposed MASTI classification system. Conclusion There is reduced bone and periarticular soft tissue injury in patients undergoing RA-TKA compared to CJ-TKA. The proposed MASTI classification system is a reproducible grading scheme for describing iatrogenic bone and soft tissue injury in TKA.