Evolving techniques in active robotic arm-assisted total knee arthroplasty: a retrospective study of pin placement...

Robotic-assisted total knee arthroplasty (RA-TKA) significantly improves surgical precision, implant alignment, and functional outcomes, but extra-incisional pin placement can lead to complications like infections, fractures, and quadriceps tethering. This study evaluates the outcomes of intra-incisional pin placement compared to traditional extra-incisional pin placement in RA-TKA using the fully active robotic system. A retrospective analysis was conducted including 1106 patients who underwent cruciate-retaining RA-TKA. Both the groups were operated by single surgeon with sub-vastus approach without tourniquet. Patients were categorized into two groups: intra-incisional pin placement (Group 1, n = 547) and extra-incisional pin placement (Group 2, n = 559). Outcomes were evaluated using the Oxford Knee Score (OKS) and Forgotten Joint Score (FJS), and complications, such as pin-site infections, fractures, stiffness, and wound issues, were compared between groups. Postoperative OKS and FJS showed comparable functional recovery between the groups, with Group 1 demonstrating slightly better patient-reported outcomes (OKS: 42.16 ± 14.78 vs. 41.78 ± 14.32; p = 0.66; 95% CI -2.09 to 1.34; FJS: 87.34 ± 17.66 vs. 84.67 ± 15.88; p < 0.008; 95% CI -4.65 to -0.69). The overall complication rate was significantly lower in Group 1 (2.01%) compared to Group 2 (14.31%, p < 0.001), with no pin-site infections or fractures in the intra-incisional group. Pin-site pain, a major concern in Group 2, was absent in Group 1 (9.12% vs. 0%, p < 0.001). Active RA-TKA can be effectively performed using intra-incisional pin placement, offering a safer alternative to extra-incisional approaches. This technique bars additional incisions, potentially lowering the risk of infection and fractures while preserving functional outcomes. Further research is needed to confirm these benefits across diverse patient populations.