Objective To summarize the research progress of the artificial wrist joint prosthesis. Methods Domestic and abroad literature concerning artificial wrist joint prosthesis was reviewed and analyzed thoroughly. Results Artificial wrist joint prosthesis has been developed to the 4th generation. The artificial wrist joint arthroplasty has advantages of pain relief and functional improvement and can achieve ideal short-term effectiveness. But there are some problems, such as loosening, subsidence, fracture, and dislocation of prosthesis. The long-term effectiveness of the 3rd and 4th generation prosthesis still need to be followed up. Conclusion The biomechanics of wrist joint is extremely complicated, which results in less application and slow development of artificial wrist joint prosthesis. Early-term effectiveness of artificial wrist joint arthroplasty is basically satisfactory, but there are still some long-term complications. So the artificial wrist joint prosthesis remains to be developed.
Objective To summarize the research progress of scaphotrapeziotrapezoid osteoarthritis (STT OA) and its etiology and clinical treatment. Methods The domestic and foreign literature on STT OA in recent years was reviewed and the research progress was summarized. Results STT OA is a common OA, which is highly prevalent in postmenopausal women and diagnosed by wrist X-ray films. The current treatment methods include conservative treatment and surgery. Among them, the conservative treatment can relieve clinical symptoms, but the long-term effectiveness is not ideal. In surgical treatment, scaphoid arthrodesis can effectively relieve wrist pain, but it sacrifices part of the range of motion and grip strength of the wrist, and there is a risk of fusion failure. Distal scaphoid resection and trapezium resection have the advantages of short operation time, simple operation, less damage to the joint capsule and ligament, and shorter postoperative external fixation time, but they lead to changes in carpal bone alignment and dorsal intercalated segmental instability. Arthroplasty can provide pain relief while restoring grip strength and preserving wrist motion, but there is a risk of dislocation of the prosthesis. Conclusion At present, there is no gold standard for the STT OA treatment. The short-term effectiveness of arthroplasty and arthroscopic distal scaphoid resection are satisfactory, but the long-term effectiveness needs further study.
Objective To design customized titanium alloy lunate prosthesis, construct three-dimensional finite element model of wrist joint before and after replacement by finite element analysis, and observe the biomechanical changes of wrist joint after replacement, providing biomechanical basis for clinical application of prosthesis. Methods One fresh frozen human forearm was collected, and the maximum range of motions in flexion, extension, ulnar deviation, and radialis deviation tested by cortex motion capture system were 48.42°, 38.04°, 35.68°, and 26.41°, respectively. The wrist joint data was obtained by CT scan and imported into Mimics21.0 software and Magics21.0 software to construct a wrist joint three-dimensional model and design customized titanium alloy lunate prosthesis. Then Geomagic Studio 2017 software and Solidworks 2017 software were used to construct the three-dimensional finite element models of a normal wrist joint (normal model) and a wrist joint with lunate prosthesis after replacement (replacement model). The stress distribution and deformation of the wrist joint before and after replacement were analyzed for flexion at and 15°, 30°, 48.42°, extension at 15°, 30°, and 38.04°, ulnar deviation at 10°, 20°, and 35.68°, and radial deviation at 5°, 15°, and 26.41° by the ANSYS 17.0 finite element analysis software. And the stress distribution of lunate bone and lunate prosthesis were also observed. Results The three-dimensional finite element models of wrist joint before and after replacement were successfully constructed. At different range of motion of flexion, extension, ulnar deviation, and radial deviation, there were some differences in the number of nodes and units in the grid models. In the four directions of flexion, extension, ulnar deviation, and radial deviation, the maximum deformation of wrist joint in normal model and replacement model occurred in the radial side, and the values increased gradually with the increase of the range of motion. The maximum stress of the wrist joint increased gradually with the increase of the range of motion, and at maximum range of motion, the stress was concentrated on the proximal radius, showing an overall trend of moving from the radial wrist to the proximal radius. The maximum stress of normal lunate bone increased gradually with the increase of range of motion in different directions, and the stress position also changed. The maximum stress of lunate prosthesis was concentrated on the ulnar side of the prosthesis, which increased gradually with the increase of the range of motion in flexion, and decreased gradually with the increase of the range of motion in extension, ulnar deviation, and radialis deviation. The stress on prosthesis increased significantly when compared with that on normal lunate bone. Conclusion The customized titanium alloy lunate prosthesis does not change the wrist joint load transfer mode, which provided data support for the clinical application of the prosthesis.
Objective To analyze the effectiveness of single 3D-printed microporous titanium prostheses versus flap combined prostheses implantation in the treatment of large segmental infectious bone defects in limbs. MethodsA retrospective analysis was conducted on the clinical data of 76 patients with large segmental infectious bone defects in the limbs who were treated between January 2019 and February 2024 and met the inclusion criteria. Among them, 51 were male and 25 were female, with an age of (47.7±9.4) years. Of the 76 patients, 51 had no soft tissue defects (single prostheses group), while 25 had associated soft tissue defects (flap combined group). The single prostheses group included 28 cases of tibial bone defects, 11 cases of femoral defects, 5 cases of humeral defects, 4 cases of radial bone defects, and 3 cases of metacarpal and carpal bone defects, with bone defect lengths ranging from 3.5 to 28.0 cm. The flap combined group included 3 cases of extensive dorsum of foot soft tissue defects combined with large segmental metatarsal bone defects, 19 cases of lower leg soft tissue defects combined with large segmental tibial bone defects, and 3 cases of hand and forearm soft tissue defects combined with metacarpal, carpal, and radial bone defects, with bone defect lengths ranging from 3.8 to 32.0 cm and soft tissue defect areas ranging from 8 cm×5 cm to 33 cm×10 cm. In the first stage, vancomycin-loaded bone cement was used to control infection, and flap repair was performed in the flap combined group. In the second stage, 3D-printed microporous titanium prostheses were implanted. Postoperative assessments were performed to evaluate infection control and bone integration, and pain recovery was evaluated using the visual analogue scale (VAS) score. Results All patients were followed up postoperatively, with an follow-up time of (35.2±13.4) months. In the 61 lower limb injury patients, the time of standing, walk with crutches, and fully bear weight were (2.2±0.6), (3.9±1.1), and (5.4±1.1) months, respectively. The VAS score at 1 year postoperatively was significantly lower than preoperatively (t=−10.678, P<0.001). X-ray films at 1 year postoperatively showed that in 69 cases (90.8%), the prostheses-bone interface was well integrated, with no complication such as infection, fractures, prostheses displacement or breakage, or nerve damage. According to the Paley scoring system for the healing of infectious bone defects, the results were excellent in 37 cases, good in 29 cases, fair in 3 cases, and poor in 7 cases. In the single prostheses group, during the follow-up, there was 1 case each of femoral prostheses fracture, femoral infection, and tibial infection, with a treatment success rate of 94.1% (48/51). In these patients, the time of fully bear weight was (5.0±1.0) months. In the flap combined group, during the follow-up, 1 case of tibial fixation prostheses screw fracture occurred, along with 2 cases of recurrent foot infection in diabetic patients and 1 case of tibial infection. The treatment success rate was 84.0% (21/25), and the time of fully bear weight was (5.8±1.2) months. The overall infection eradication rate for all patients was 93.4% (71/76). Conclusion The use of 3D-printed microporous titanium prostheses, either alone or in combination with flaps, for the treatment of large segmental infectious bone defects in the limbs results in good effectiveness with a low incidence of complications. It is a feasible strategy for the reconstruction of infectious bone defects.