【Abstract】 Objective To evaluate the feasibility and effectiveness of reconstruction of mandibular bone defects using three-dimensional skull model and individualized titanium prosthetics from computer assisted design. Methods Between July 2002 and November 2009, 9 patients with mandibular defects accepted restorative operation using individualized bone prosthetics. Among 9 cases, 4 were male and 5 were female, aged 19-55 years. The causes of mandibulectomy were benign lesions in 8 patients and carcinoma of gingival in 1 patient. Mandibular defects exceeded midline in 2 cases, involved condylar in 4 cases, and was limited in one side without involvement of temporo-mandibular joint in 3 cases. The range of bone defects was 9.0 cm × 2.5 cm-17.0 cm × 2.5 cm. The preoperative spiral CT scan was performed and three-diamensional skull model was obtained. Titanium prosthetics of mandibular defects were designed and fabricated through multi-step procedure of reverse engineering and rapid prototyping. Titanium prosthetics were used for one-stage repair of mandibular bone defects, then two-stage implant denture was performed after 6 months. Results The individualized titanium prosthetics were inserted smoothly with one-stage operative time of 10-23 minutes. All the cases achieved incision healing by first intention and the oblique mandibular movement was corrected. They all got satisfactory face, had satisfactory contour and good occlusion. In two-stage operation, no loosening of the implants was observed and the abutments were in good position with corresponding teeth which were designed ideally before operation. All cases got satisfactory results after 1-9 years of follow-up. At last follow-up, X-ray examinations showed no loosening of implants with symmetry contour. Conclusion Computer assisted design and three-dimensional skull model techniques could accomplish the design and manufacture of individualized prosthetic for the repair of mandibular bone defects.
Objective To investigate the value of computer-aided design (CAD) in defining the resection boundary, reconstructing the pelvis and hip in patients with pelvis tumors. Methods Between November 2006 and April 2009, 5 cases of pelvis tumors were treated surgically using CAD technology. There were 3 males and 2 females with an average age of 36.4 years (range, 24-62 years). The cause was osteosarcoma, giant cell tumor of bone, and angiosarcoma in 1 case, respectively,and chondrosarcoma in 2 cases. According to the Enneking system for staging benign and mal ignant musculoskeletal tumors, regions I, I + II, III, IV, and I + IV is in 1 case, respectively. According to the principle of reverse engineering, 5 patients with pelvis tumors were checked with lamellar CT/MRI scanning, whose two-dimensional data were obtained in disease area. The three-dimensional reconstruction of pelvic anatomical model, precise resection boundary of tumor, individual surgical template, individual prosthesis, and surgical simulation were precisely made by computer with CAD software. Based on the proposal of CAD, the bone tumor was resected accurately, and allograft il ium with internal fixation instrument or allogeneic il ium with personal ized prosthetic replacement were used to reconstruct the bone defect after tumor was resected. Results The operation was successfully performed in 5 cases. The average operation time was 7.9 hours, and the average blood loss was 3 125 mL. Hemorrhage and cerebrospinal fluid leakage occurred in 1 case, respectively, and were cured after debridement. Five patients were followed up from 24 to 50 months (mean, 34.5 months). All patients began non-weight bearing walk with double crutches at 4-6 weeks after operation, and began walk at 3-6 months after operation. Local recurrence developed in 2 patients at 18 months after operation, and resection and radiotherapy were performed. According to International Society of Limb Salvage criteria for curative effectiveness of bone tumor l imb salvage, the results were excellent in 2 and good in 3. Conclusion The individual surgical template, individual prosthesis, and surgical simulation by CAD ensure the precision and rel iabil ity of pelvis tumors resection. The CAD technology promotes pelvis tumor resection and the reconstruction of pelvis to individual treatment stage, and good curative effectiveness can be obtained.
Objective To improve the fitness and initial fixation strength between the hip and bone and to optimize the shape of the prosthetic implants. Methods The cross-section of hip canal was automatically extracted by Image processing. By using taper curve fit,hypocurve predigesting and the curve of shape center fit, the parameters of long-short diameter and the curve of shape center were got to design the hip shape.CAD was adopted to analyze and evaluate the configuration of bone and shape of hip.The “peg-in-hole” was employed to optimize the shape of implant by the visual test of “Drawingout” in computer. Results 23.2% hip-bone average matching rate and 0.033% bone damage rate were presented by CAD analysis. The implant extraction path were validated visually and quantitatively by measuring the maximum amount of overlap in the path configuration. Conclusion The valuable method for prothsetic hip design was presented by the way of image processing,graphics design and optimizingdesign in this study.
ObjectiveTo study the feasibility of preparation of the individualized femoral prosthesis through computer assisted design and electron beammelting rapid prototyping (EBM-RP) metal three-dimensional (3D) printing technology. MethodsOne adult male left femur specimen was used for scanning with 64-slice spiral CT; tomographic image data were imported into Mimics15.0 software to reconstruct femoral 3D model, then the 3D model of individualized femoral prosthesis was designed through UG8.0 software. Finally the 3D model data were imported into EBM-RP metal 3D printer to print the individualized sleeve. ResultsAccording to the 3D model of individualized prosthesis, customized sleeve was successfully prepared through the EBM-RP metal 3D printing technology, assembled with the standard handle component of SR modular femoral prosthesis to make the individualized femoral prosthesis. ConclusionCustomized femoral prosthesis accurately matching with metaphyseal cavity can be designed through the thin slice CT scanning and computer assisted design technology. Titanium alloy personalized prosthesis with complex 3D shape, pore surface, and good matching with metaphyseal cavity can be manufactured by the technology of EBM-RP metal 3D printing, and the technology has convenient, rapid, and accurate advantages.
ObjectiveTo evaluate the effectiveness of three-dimensional (3D) printing navigation templates assisting reconstruction with personalized unrestricted total knee prosthesis to treat maliganant bone tumors around the knee. MethodsBetween March 2007 and September 2014, 43 patients with malignant tumor around the knee were divided into 2 groups: 3D printing navigation templates assisting reconstruction with personalized unrestricted total knee prosthesis were used in 21 cases (trial group), and conventional tumor resection and reconstruction with hinged total knee prosthesis were used in 22 cases (control group). There was no significant difference in age, gender, tumor location, pathological diagnosis, tumor stage, diameter of tumor, disease duration, and preoperative visual analogue scale (VAS) score between 2 groups (P>0.05), which were comparable. Intraoperative length of tumor resection and blood loss were recorded and compared, and the postoperative complications and tumor recurrence were observed. The Musculoskeletal Tumor Society (MSTS) score was used to evaluate knee joint function. ResultsThe operations were completed successfully in the patients of 2 groups and postoperative pathological results were negative in tumor resection margin. All the patients were followed up 12-77 months (mean, 36.7 months). There was no significant difference in the length of tumor resection and blood loss between trial group and control group (t=1.01, P=0.32; t=-0.76, P=0.45). In trial group, the resection range and reconstruction results were consistent with preoperative computer simulation; postoperative complications happened in 2 cases (9.52%); 1 case of immunological rejection and 1 case of infection); 2 cases (9.52%) had recurrence of osteosarcoma and pulmonary metastasis at 1 year after operation. In the control group, complication occurred in 6 cases (27.27%; 2 cases of periprosthetic fractures, 2 cases of infection, 1 case of incision nonunion, and 1 case of common peroneal nerve injury); 4 cases (18.18%) had recurrence of osteosarcoma and metastasis at 1 year after operation. There was no significant difference in postoperative complication and recurrence rate between 2 groups (χ2=2.24, P=0.14;χ2=0.67, P=0.41). At last follow-up, distal femur score of tumor and proximal tibial score of tumor in trial group were significantly better than those in control group (t=4.89, P=0.00; t=3.94, P=0.00). The mean flexion and extension range of motion of the knee joint was (115.45±12.25)° in trial group and was (101.49±11.96)° in control group, showing significant difference (t=3.78, P=0.00). ConclusionThe effectiveness using 3D printing navigation templates assisting reconstruction with personalized unrestricted prosthesis for maliganant bone tumors around the knee is better than conventional tumor resection and reconstruction with hinged total knee prosthesis. It can improve the joint function better and the patients' quality of life.
Objective To explore the clinical methods of resection of elbow tumor and total elbow replacement with custom personalized prosthesis based on three dimensional (3-D) printing navigation template. Methods In August 2016, a 63-year-old male patient with left elbow joint tumor was treated, with the discovery of the left distal humerus huge mass over 3 months, with elbow pain, activity limitation of admission. Computer-assisted reduction technique combined with 3-D printing was used to simulate preoperative tumor resection, a customized personal prosthesis was developed; tumor was accurately excised during operation, and the clinical result was evaluated after operation. Results The time was 46 minutes for tumor resection, and was 95 minutes for personalized implant and allograft bone without fluoroscopy. X-ray and CT examination at 1 week after operation showed good position of artificial elbow joint; the anteversion of ulna prosthesis was 30° and the elbow carrying angle was 15°, which were consistent with the simulated results before surgery. The finger flexion was normal at 1 month after operation; the range of motion was 0-130° for elbow flexion and extension, 80° for forearm pronation, and 80° for forearm supination. The elbow function was able to meet the needs of daily life at 7 months after operation, and no recurrence and metastasis of tumor were observed. Conclusion For limb salvage of elbow joint, computer aided design can make preoperative surgical simulation; the navigation template can improve surgical precision; and the function of elbow joint can be reconstructed with customized and personlized prosthesis for total elbow replacement.
Objective To explore the therapeutic effect of rehabilitation therapy combined with computer-aided design and computer-aided manufacture (CAD/CAM) of orthopedic insoles on deputy scaphoid inflammation. Methods We selected the patients with deputy scaphoid inflammation who had treated in Sichuan Province Orthopedic Hospital between July 2018 and February 2020. The patients were randomly divided into control group and experimental group by drawing lots. The control group received rehabilitation therapy, while the experimental group received rehabilitation therapy combined with CAD/CAM orthopedic insoles. The clinical efficacy was tested at the 5th and 12th weeks after treatment, and the foot pain was assessed by Visual Analogue Scoring (VAS), and the foot function was assessed by the American Orthopaedic Foot and Ankle Association (AOFAS) scale. Results A total of 78 patients were included, and 3 patients dropped out. There was no significant difference in sex, age, weight or course of disease between the two groups (P>0.05). Before treatment, there was no statistically significant difference in VAS score (t=0.329, P=0.743) or AOFAS score (t=0.431, P=0.668) between the two groups. At the 5th and 12th weeks after treatment, the VAS score of the experimental group was lower than that of the control group (t=4.517, 5.299; P<0.001), and the AOFAS score was higher than that of the control group (t=6.239, 5.779; P<0.001). Over time, the VAS score of the two groups decreased (P<0.05), while the AOFAS score increased (P<0.05). Conclusion Rehabilitation therapy combined with CAD/CAM of orthopedic insoles have better curative effect than traditional rehabilitation therapy for deputy scaphoid inflammation.
Objective To compare the effect of three-dimensional visual (3DV) model, three-dimensional printing (3DP) model and computer-aided design (CAD) modified 3DP model in video-assisted thoracoscopic surgery (VATS) sublobular resection. MethodsThe clinical data of patients who underwent VATS sublobular resection in the Affiliated Hospital of Hebei University from November 2021 to August 2022 were retrospectively analyzed. The patients were divided into 3 groups including a 3DV group, a 3DP group and a CAD-3DP group according to the tools used. The perioperative indexes and subjective evaluation of operators, patients and their families were compared. ResultsA total of 22 patients were included. There were 5 males and 17 females aged 32-77 (56.95±12.50) years. There were 9 patients in the 3DV group, 6 patients in the 3DP group, and 7 patients in the CAD-3DP group. There was no statistical difference in the operation time, intraoperative blood loss, drainage volume, hospital stay time or postoperative complications among the groups (P>0.05). Based on the subjective evaluations of 4 surgeons, the CAD-3DP group was better than the 3DV group in the preoperative planning efficiency (P=0.025), intuitiveness (P=0.045) and doctor-patient communication difficulty (P=0.034); the CAD-3DP group was also better than the 3DP group in the overall satisfaction (P=0.023), preoperative planning difficulty (P=0.046) and efficiency (P=0.014). Based on the subjective evaluations of patients and their families, the CAD-3DP group was better than the 3DP group in helping understand the vessel around the tumor (P=0.016), surgical procedure (P=0.020), procedure selection (P=0.029), and overall satisfaction (P=0.048); the CAD-3DP group was better than the 3DV group in helping understand the tumor size (P=0.038). ConclusionCAD-modified 3DP model has certain advantages in pre-planning, intraoperative navigation and doctor-patient communication in the VATS sublobectomy.