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Objective: Scaphoid and lunate fractures have a relatively high incidence rate. Traditional carpectomy and carpal arthrodesis in the treatment of carpal osteonecrosis will lead to many complications. Three-dimensional (3D) printed tantalum has good biocompatibility and can be designed to match the patient’s personalized anatomical carpal structure. This study aims to investigate carpal function and prosthesis-related conditions after carpal bone replacement using 3D printed tantalum prostheses.Methods: From July 2020 to January 2022 at our center, seven patients with osteonecrosis of the carpus received carpal bone replacement using 3D printed tantalum prosthesis. The Disability of the Arm, Shoulder and Hand (DASH) score and patient satisfaction, as well as the Mayo Wrist Scores (Cooney method, modified Green, and O’Brien wrist score), were used to evaluate the preoperative and postoperative wrist function of patients. The Visual Analog Scale (VAS) pain scores were also recorded before and after surgery. The angles of flexion, dorsiflexion, ulnar deviation, and radial deviation were measured using an arthrometer. The grip strength and pinch strength of the operated hand after carpal bone replacement and the contralateral healthy carpus were measured using a dynamometer. Radiographs were taken to confirm the condition and complications of the tantalum prosthesis.Results: All seven patients were followed for 19.6 ± 2.7 months. At the last follow-up, the grip strength of the operated wrist joint after carpal bone replacement was 33.4 ± 2.3 kg, the pinch strength was 8.9 ± 0.7 kg, the flexion was 54.6° ± 0.8°, the dorsiflexion was 54.7° ± 1.7°, the ulnar deviation was 34.6° ± 1.9°, and the radial deviation was 25.9° ± 0.8°, all of which showed no statistically significant difference with the contralateral healthy carpus (p > 0.05). There were significant differences in the VAS, DASH, and MAYO scores between the preoperative and the last follow-up (p < 0.01). Patients had reduced postoperative pain and improved wrist function and range of motion (ROM), and the tantalum prostheses were stable.Conclusion: The 3D printed tantalum brings us new hope, not only for hip or knee replacement, but also for joint replacement of other complex anatomical structures, and patients with other irregular bone defects such as bone tumors and deformity, which could realize personalized treatment and precise medicine.

Fractures of the radial head account for 33% of elbow fractures. More and more studies have found that the radial head plays an important role in the normal function of the elbow joint, and many complications will occur after resection of the radial head. Accurate treatment of radial head fractures is crucially important. At this stage, commercialized radial head prosthesis of fixed size is commonly used in radial head replacement, but the mismatch of prosthesis and material problems have resulted in many complications. The three-dimensional (3D) printed porous tantalum has good biocompatibility, is conducive to bone ingrowth, has ideal elastic modulus, and can be prepared into a highly porous material that can be designed to match the radial head according to each patient's personalized anatomical structure. The purpose of this study was to investigate the elbow joint function, complications and prosthesis conditions after radial head replacement using 3D printed porous tantalum. Seven patients with comminuted fracture of radial head in our Center received radial head replacement using 3D printed porous tantalum. Patients were followed on the elbow joint function, range of motion (ROM), elbow radiographs, postoperative complications, and bone condition of tantalum metal. quality situation. Follow-up data showed that the patients had less postoperative pain, improved elbow function and ROM, and bone ingrowth in the tantalum prosthesis. The 3D printing porous tantalum can be applied to hip replacement, knee replacement, and other patients with irregular bone defects such as bone tumor, bone deformity, etc., which has the potential to realize personalized and precise treatment.

Although customized three-dimensional tantalum implants have been used to treat a large variety of diseases, few reports have described the application of such implants to reconstruct large pelvic bone defects after the removal of massive tumors. We herein describe a 30-year-old woman with a 9-year history of a massive low-grade chondrosarcoma in the pelvic bone. After removal of a solid 12- × 8- × 6-cm tumor with clear margins, we used a customized three-dimensional printed tantalum implant to fill the large pelvic bone defect and performed hip arthroplasty in a one-step surgery. The patient’s postoperative recovery was uneventful. She started walking 1 month after surgery, and she developed no tumor recurrence, instrumentation failure, or implant loosening during the 12-month follow-up period. This report describes the successful application of a customized three-dimensional printed implant to reconstruct a massive pelvic bone defect. Satisfactory functional recovery was achieved with no apparent complications. The methodology of the current case may benefit orthopedic and oncologic surgeons in designing treatment strategies for similar cases.

Background Three-dimensional (3D) reconstruction has been used for various diseases, but few reports have described its application in pelvic reconstruction after removal of giant chondrosarcoma. Case reports describing the clinical application of personalized 3D-printed titanium implants are needed for future clinical reference. Case presentation: We herein describe a 29-year-old woman with a giant chondrosarcoma treated with a personalized 3D titanium implant. The surgery was successful, and the patient recovered with significant pain relief and good functional recovery after the surgery. No implant-related complications occurred during the 12-month follow-up. The current case represents successful application of 3D printing technology to the treatment of a massive bone defect due to the removal of a giant osteoporotic tumor. Conclusions Personalized 3D titanium implants can be used in the reconstruction of massive bone defects after the removal of giant pelvic sarcomas. The methodology and results described in the current case report can be a used as reference in the treatment of similar cases in future.

The aim of this study was to evaluate the effects of niacin in diet on the expression of nitric oxide synthase (NOS) in rat lungs of the animal model of silicosis established by direct tracheal instillation of silica particles into rat lungs surgically. The niacin concen- tration in serum was analyzed by high performance liquid chromatography (HPLC). The expression of inducible nitric oxide synthase (iN- OS) protein in paraffin-embedded lung sections was determined by streptavidin/peroxidase (SP) staining. Quantitative analysis by Image- Pro Plus was also performed on the expression of iNOS. The results showed that niacin concentration in serum of the niacin-treated rats was significantly higher than that in the control and silica-treated rats. After 7 days of silica instillation, iNOS integrated optical density (IOD) in rat lungs and total NOS and iNOS activities in bronchoalveolar lavage fluid (BALF) in silica-treated rats rose by 273420.75, 2.61 units! mL and 1.89 units/mL respectively, when compared with those in the control rats. Niacin treatment significantly reduced silica-induced iNOS IOD in rat lung tissues and total NOS and iNOS activities in BALF supernatant by 248292.35, 1.50 units/ml and 0.91 units nil, respectively, as compared with those in silica-treated rats. Therefore, niacin can effectively attenuate the pathological expression of NOS in rat lung tissues induced by silica particles. [ABSTRACT FROM AUTHOR]