Computed tomography and structured light imaging guided orthopedic navigation puncture system: effective reduction of intraoperative image drift and mismatch

BackgroundImage-guided surgical navigation systems are widely regarded as the benchmark for computer-assisted surgical robotic platforms, yet a persistent challenge remains in addressing intraoperative image drift and mismatch. It can significantly impact the accuracy and precision of surgical procedures. Therefore, further research and development are necessary to mitigate this issue and enhance the overall performance of these advanced surgical platforms.ObjectiveThe primary objective is to improve the precision of image guided puncture navigation systems by developing a computed tomography (CT) and structured light imaging (SLI) based navigation system. Furthermore, we also aim to quantifying and visualize intraoperative image drift and mismatch in real time and provide feedback to surgeons, ensuring that surgical procedures are executed with accuracy and reliability.MethodsA CT-SLI guided orthopedic navigation puncture system was developed. Polymer bandages are employed to pressurize, plasticize, immobilize and toughen the surface of a specimen for surgical operations. Preoperative CT images of the specimen are acquired, a 3D navigation map is reconstructed and a puncture path planned accordingly. During surgery, an SLI module captures and reconstructs the 3D surfaces of both the specimen and a guiding tube for the puncture needle. The SLI reconstructed 3D surface of the specimen is matched to the CT navigation map via two-step point cloud registrations, while the SLI reconstructed 3D surface of the guiding tube is fitted by a cylindrical model, which is in turn aligned with the planned puncture path. The proposed system has been tested and evaluated using 20 formalin-soaked lower limb cadaver specimens preserved at a local hospital.ResultsThe proposed method achieved image registration RMS errors of 0.576 ± 0.146 mm and 0.407 ± 0.234 mm between preoperative CT and intraoperative SLI surface models and between preoperative and postoperative CT surface models. In addition, preoperative and postoperative specimen surface and skeletal drifts were 0.033 ± 0.272 mm and 0.235 ± 0.197 mm respectively.ConclusionThe results indicate that the proposed method is effective in reducing intraoperative image drift and mismatch. The system also visualizes intraoperative image drift and mismatch, and provides real time visual feedback to surgeons

Medium-term results following arthroscopic reduction in walking-age children with developmental hip dysplasia after failed closed reduction

Abstract Background Arthroscopic reduction has become increasingly popular as an alternative to open reduction for the treatment of developmental dysplasia of the hip (DDH). However, patient outcomes beyond one and a half years after surgery remain unclear. The purpose of this study is to report the medium-term outcomes of walking-age patients who received arthroscopic reduction after an unsuccessful closed reduction. This research was conducted as part of a retrospectively registered study. Methods We performed arthroscopic reduction in eight children with DDH after failed closed reduction between January 2010 and January 2012 and followed all cases for a minimum of 5 years. Arthroscopic reduction was performed using a two-portal approach without traction. Capsular release and resection of the transverse acetabular ligament were also performed if needed. Patient demographics, clinical variables, anatomical assessment measures, and post-operative complications were extracted from medical records. Results We treated five male and three female patients with an average age at operation of 15.6 months (range, 12 to 22 months). All obstacles to reduction were corrected arthroscopically. Concentric reduction of the hip joint was observed in post-operative X-rays in all cases. The average safe zone was increased from 17.5° (8° to 30°) to 42.1° (36° to 50°) after the operation. The average acetabular (AC) index was reduced from 40.3° (33° to 65°) to 21.9° (19° to 26°) at the end of follow-up. No complications occurred and no patients developed necrosis of the femoral head, recurrent dislocation, or residual hip dysplasia. Conclusions Arthroscopic reduction is a suitable surgical procedure for the treatment of DDH among walking-age children with failed closed reduction and severe dislocation. This method is quick and safe, and it can be performed without post-operative complications over the medium term