Robotic-assisted total knee arthroplasty improved component alignment in the coronal plane compared with navigation-assisted total knee arthroplasty: a comparative study.

The purpose of this study was to directly compare implant placement accuracy and postoperative limb alignment between robotic-assisted total knee arthroplasty and navigation-assisted total knee arthroplasty. This retrospective case-control study included a consecutive series of 182 knees (robotic-assisted group, n = 103 knees; navigation-assisted group, n = 79). An image-free handheld robotic system (NAVIO) or an image-free navigation system (Precision N) was used. Component and limb alignment were evaluated on three-dimensional computed tomography scans and full-length standing anterior-posterior radiographs. We compared the errors between the final intraoperative plan and the postoperative coronal and sagittal alignment of the components and the hip-knee-ankle angle between the two groups. The orientation of the femoral and tibial components in the coronal plane were more accurate in the robotic-assisted group than in the navigation-assisted group (p < 0.05). There was no significant difference in the orientation of the femoral and tibial component in the sagittal plane between the two groups. There were fewer outliers in the tibial coronal plane in the robotic-assisted group (p < 0.05). There was also no significant difference in the frequency of outlying values for coronal or sagittal alignment of the femoral component or sagittal alignment of the tibial component or the hip-knee-ankle angle between the two groups. Robotic-assisted total knee arthroplasty using a handheld image-free system improved component alignment in the coronal plane compared with total knee arthroplasty using an image-free navigation system. Robotic surgery helps surgeons to achieve personalised alignment that may result in better clinical outcomes.

Intracanalicular Osteochondroma in the Lumbar Spine.

Osteochondroma is a common benign bone tumor that is relatively rare in the spine. Here, we report two cases of symptomatic solitary osteochondroma of the lumbar spine. The first case was a 61-year-old man who presented with a 2-year history of right leg numbness. Imaging findings showed that the cause of the radiculopathy was osteochondroma of the right inferior articular process at L4. The tumor was removed en bloc, and the numbness resolved. The second case was a 62-year-old man with osteochondroma of the right superior articular process at L5 that caused pain and numbness in the right leg. En bloc resection of the osteochondroma with the ligamentum flavum relieved the symptoms. Spinal osteochondroma occurs relatively frequently in elderly individuals compared with peripheral lesions and mimics a degenerative spinal disorder. Careful physical examination and imaging evaluation can reveal this tumor and surgery is effective for relieving the symptoms.