Prospective non-randomized comparative clinical outcome of computer assisted total knee arthroplasty with and without a minimally invasive approach.

OBJECTIVE: Compare clinical outcomes of computer assisted total knee arthroplasty using the LCS knee implant with (CAMITKA) and without (CATKA) minimally invasive surgery.

MATERIAL AND METHOD: The author prospectively performed 71 computer-assisted total knee arthroplasties (TKA) in group of the present study using the Ci navigation system in a non-randomized manner.

RESULTS: CAMITKA subjects had a mean operation time of 105 minutes, average incision length of 9.1 cm, mean total blood loss of 541 ml, mean time to ambulation of 25.4 hours, and required approximately 10 and 18 days using walkers and canes respectively, before ambulating unaided CATKA subjects had a mean operation time of 81 minutes, average incision length of 13.5 cm, mean total blood loss of 599 ml, mean time to ambulation of 45.4 hours, and required 17 and 27.5 days using walkers and canes respectively, before ambulating unaided. All outcome differences have statistical significances, except blood loss. Mechanical axis alignment measured from post-operative radiographic assessment showed that 2.5% of all knees were outliers and average axis deviations were 1.39 degrees and 1.34 degrees for CAMITKA and CATKA subjects, respectively. No complications were detected. CAMITKA is advantageous with respect to recovery time.

CONCLUSION: Minor surgical pitfalls were experienced with CAMITKA regarding visualization and initial registration of the navigation system. However, they may be corrected by coupling navigation with CT scan, fluoroscopy, and/or ultrasound Additionally, accurate mechanical axis alignment shows that computer assisted surgery technology allows minimal invasive surgery in TKA because it allows visualization of areas not directly revealed without aid.