COMPUTER-ASSISTED NAVIGATION IN TOTAL KNEE REPLACEMENT

The accuracy of implantation using computer navigation and robotic total knee replacement (TKR) has been proven. Time taken during surgery has been a factor for surgeons for not using the technology. Aim of this study was to analyse time taken in different steps and identify which part needs improvement. Robotic time was compared to computer navigation. Methods: 15TKR were performed with MAKO robot. Software for the ligament balancing was used. All had CT scan preoperatively. Time of different surgical steps was recorded. Time for computer navigation was recorded too. After joint exposure, trackers and verification pins for tibia and femur were inserted. Femoral registration matching started at 10.8 minutes (SD3.3 Range7-20). It took 3.2 minutes to match femoral anatomy to CT scan. Tibial registration done at 14.1minutes (SD3 Range10- 23). Once matching was accepted to required accuracy, tibial cut was made at 22.2 minutes (SD4.4 Range 15-30). Next the soft tissues were assessed with tensioner. It took 6.3 minutes (SD 5.6). Final femoral preparation done at 35.7 minutes (SD 5.6 Range25-45). Trial performed at 52 minutes (SD7.3 Range42-63). Implants were cemented at 63.4 minutes (SD8 Range50-72). Wound closed at 77.6 minutes (SD9.5 Range65-97). The computer navigated TKR surgery took 70 minutes on an average. Compared to navigation, robotic technique took approximately 7 minutes longer, not significantly different. This could be due to learning curve of the surgical and theatre team. Improvement is required in different steps. The familiarity of staff will increase the efficiency. Registration matching took 11.4 minutes. Femoral preparation took 17 minutes. These steps could be streamlined.

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Gap Deviation after Cementation in Computer Assisted Navigation TKA

10.29007/t7tz ◽

2019 ◽

Author(s):

Chumroonkiet Leelasestaporn ◽

Tomorn Tarnpichprasert

Keyword(s):

Soft Tissue ◽

Total Knee Replacement ◽

Knee Replacement ◽

Mechanical Axis ◽

Mobile Bearing ◽

Flexion Contracture ◽

Implant Design ◽

Computer Assisted ◽

Assisted Navigation ◽

Total Knee

INTRODUCTIONThe outcome of knee replacement depended on alignment, balancing of soft tissue, symmetrical andrectangular gaps adjustment, and accurate implant placement. Many techniques have been used toimprove these factors including navigator assisted knee replacement, which has precise bone cutand accurate soft tissue balancing. However, cementation may change gaps and alignment that canaffect outcome of knee replacement.OBJECTIVETo compare gaps and alignment after cementation in computer assisted total knee replacementMATERIAL AND METHODSProspective collecting data all cases performed computer assisted total knee replacement withcruciate retaining - mobile bearing implant design. Gaps and mechanical axis was collected andcompered between complete trial prosthesis and final cementation.RESULTLateral extension gap and flexion contracture significantly increase after cementation whencompared with trial implantation [0.6 mm (P = 0.021), 2.7o (P = 0.00)]. The mechanical axis was notdeviated after cementation (P = 1.00).CONCLUSIONCementation is able to influence gap and alignment. It may be useful to control and recheck gap andalignment with navigation system during cementation. Clinical correlation needs furtherinvestigation.

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