Prospective Randomized Trial of Navigated and Conventional TKA

Evaluation of the component position and kinematics after navigated and conventional Total Knee Arthroplasty.

Component position, kinematics After skin closure lateral x-rays were done in different flexion angles in order to evaluate the kinematic behaviour of the TKA. A full-length standing and a lateral radiograph as well as CT scans of the hip, knee and ankle joint were performed 5 to 7 days postoperatively before discharge. clinical outcome Patient sociodemographic and anamnestic data were collected. The written interview was complemented by the EuroQol questionnaire (release EQ-5D) and the assessment of the patients' functional status (Knee Society Score) one week before surgery and 18 to 24 month after surgery.

In all patients a cemented, unconstrained, cruciate-retaining TKA with a rotating platform (ScorpioTM PCS, Stryker Orthopaedics, Mahwah, NJ) was implanted. No patellar resurfacing was performed. A medial parapatellar approach with a femur-first preparation was done in all cases. The Stryker Navigation System, Knee Navigation Software V3.1 (Stryker Orthopaedics, Mahwah, NJ) was used for computer-assisted implantation. The conventional implantation was performed with femoral intramedullary and tibial extramedullary standard alignment guides.

Inclusion Criteria: primary or secondary osteoarthritis of the knee indication to TKA a mechanical axis between 20° varus and 5° valgus signed informed consent Exclusion Criteria: previous hemi- or total arthroplasty severe instability that could not be treated with an unconstrained, cruciate-retaining TKA

Lutzner J, Krummenauer F, Wolf C, Gunther KP, Kirschner S. Computer-assisted and conventional total knee replacement: a comparative, prospective, randomised study with radiological and CT evaluation. J Bone Joint Surg Br. 2008 Aug;90(8):1039-44. doi: 10.1302/0301-620X.90B8.20553.

Beyer F, Pape A, Lutzner C, Kirschner S, Lutzner J. Similar outcomes in computer-assisted and conventional total knee arthroplasty: ten-year results of a prospective randomized study. BMC Musculoskelet Disord. 2021 Aug 18;22(1):707. doi: 10.1186/s12891-021-04556-3.

Harman MK, Banks SA, Kirschner S, Lutzner J. Prosthesis alignment affects axial rotation motion after total knee replacement: a prospective in vivo study combining computed tomography and fluoroscopic evaluations. BMC Musculoskelet Disord. 2012 Oct 23;13:206. doi: 10.1186/1471-2474-13-206.

Lutzner J, Krummenauer F, Gunther KP, Kirschner S. Rotational alignment of the tibial component in total knee arthroplasty is better at the medial third of tibial tuberosity than at the medial border. BMC Musculoskelet Disord. 2010 Mar 25;11:57. doi: 10.1186/1471-2474-11-57.