Abstract
The conventional Knee arthroplasty jigs, while being usually accurate, often result in prostheses being inserted in an undesired alignment resulting in poor postoperative outcome. This is especially true about unicompartmental knee replacement. Computer navigation and roboticaly assisted unicompartmental knee replacement were introduced in order to improve surgical accuracy of the femoral and tibial bone cuts.
The aim of this study was to assess accuracy and reliability of robotic assisted, unicondylar knee surgery (Makoplasty) in producing reported bony alignment. Two hundred and twenty consecutive patients who underwent medial robotic assisted unicondylar knee surgery (Makoplasty) performed by two surgeons (RJ & GP) were retrospectively identified and included in the study. Femoral and tibial sagittal and coronal alignments and posterior slope of the tibial component were measured in the post-operative radiographs. These measurements were compared with the equivalent measurements collected during intra-operative period by the navigation to study the reliability and accuracy of femoral and tibial cuts.
Results
We found an average difference of 2.2 to 3.6 degrees between the intra-operatively planned and post-operative radiological equivalent measurements.
In conclusion: assuming appropriate planning, robotically assisted surgery in unicondylar knee replacement will result in reliably accurate positioning of component and reduce early component failures caused by malpositioning. Mismatch between preplanning and post-op radiography is caused by poor cementing technique of the prosthesis rather than wrong bony cuts.
