Objective To evaluate the surgical skill, cause of revision, compl ications, prosthetic survival and postoperative function in revision of custom-made tumor prosthesis replacement of knee joint. Methods The cl inical data of 33 patients who received prosthetic revision surgery between June 2002 and June 2007 were reviewed. There were 17 malesand 16 females with an average age of 33.1 years (range, 16-67 years). The pathological diagnosis included 17 osteosarcomas, 11 giant cell tumors, 2 mal ignant fibrous histocytomas, 1 chondrosarcoma, 1 synovial sarcoma, and 1 l iposarcoma. The involved locations were distal femur in 22 cases and proximal tibia in 11 cases. The average interval between first prosthetic replacement and revision surgery was 45.3 months (range, 6-180 months). The reason for revision included local recurrence in 2 cases, deep infection in 8 cases, aseptic loosening in 7 cases, peri prosthetic fracture in 1 case, prosthetic stem fracture in 6 cases, and prosthetic hinge failure in 9 cases. Six patients with deep infection received two-stage revision surgery, while the other 27 patients received one-stage revision. Cemented prostheses were used in all patients. Allograft prosthetic composite and revisions were used in 2 patients who had deficit of diaphysis for stem fixation. Results In 17 patients who received both primary prosthetic replacement and revision, the operative time was (149.8 ± 40.5) minutes and (189.9 ± 43.8) minutes, and the blood loss was (605.2 ± 308.0) mL and (834.1 ± 429.9) mL for primary prosthetic replacement and revision, respectively; all showing statistically significant differences (P lt; 0.05). The mean time of follow-up was 45.1 months (range, 12-76 months). Heal ing between allograft and host bone was obtained in 2 patients with allograft prosthetic composite and revision after 1.5 years and 2 years, respectively. After revision surgery, 3 patients died of lung metastasis after 12-24 months, and other 3 patients havinglung metastasis were al ive with disease. Nine (30%) compl ications occurred in 30 patients who were al ive at last follow-up. The compl ications included wound infection in 2 patients, deep infection in 5 patients, mechanical problems in 2 patients. Prosthetic failure occurred in 7 patients (23.3%). The 5-year survival rate of revised prosthesis was 68.6%. The Musculoskeletal Tumor Society (MSTS) score at 6 months after revision (73.6% ± 14.4%) was significantly improved (P lt; 0.01) when compared with before revision (57.1% ± 10.6%). Conclusion The main reasons for revision of custom-made tumor prosthesis of knee joint were mechanical problems and deep infection. Although revision surgery of knee is relatively compl icated and has some compl ications, a functional l imb could be maintained in most tumor patients.
ObjectiveTo observe the effectiveness of digital customized plate in the treatment of complex limb fracture. MethodsBetween January 2012 and May 2013, CT raw data of complex limb fracture were used to establish the fracture three-dimensional simulation model after reduction, and a customized personalized anatomic plate was designed and used for internal fixation after open reduction in 42 cases. There were 22 males and 20 females, aged 16-53 years (average, 37.4 years). The causes of injury were traffic accident in 21 cases, falling from height in 18 cases, crush by heavy objects in 3 cases, including 26 cases of fresh closed fracture and 16 cases of open fracture (9 cases of type Ⅰ and 7 cases of type Ⅱ according to Gustilo classification). According to AO classification, there were 15 cases of humerus comminuted fracture, 4 cases of radial comminuted fracture, 8 cases of femoral comminuted fracture, and 15 cases of tibia comminuted fracture. The interval of injury and operation was 6-28 days (mean, 10 days). ResultsReduction and internal fixation of fracture were successfully performed on 42 patients. The length and position of digital customized plate, direction and length of screw implant, number of screw were basically identical with preoperative design. The operation time was 35-120 minutes (mean, 70 minutes); the blood loss volume was 30-500 mL (mean, 180 mL); and X ray fluoroscopy frequency was 2-6 times (mean, 3 times). Superficial infection occurred in 2 cases, and was cured after dressing change; primary healing of incision was obtained in the other patients. Forty-two cases were followed up 6-24 months with an average of 11.5 months. The fracture healing time was 8-19 weeks (mean, 14 weeks) in 41 cases; delayed union occurred in 1 case at 44 weeks after operation. The fracture anatomical reduction was achieved in 19 cases, malunion in 3 cases, and functional reduction in the other patients. At last follow-up, no plate and screw loosening and breakage was observed. ConclusionDigital customized plate in treatment of complex fractures of limbs, especially for the multiple comminuted fracture of long bones of the limbs has the advantages of convenient operation, less trauma, fewer complications, and good effectiveness.
ObjectiveTo explore the application of three-dimensional (3D) printing technology in precise and individualized surgical treatment of severe distal humeral bone defect.MethodsFive patients with severe distal humeral bone defects were treated with customized 3D printing prostheses between December 2010 and December 2015. There were 4 males and 1 female, with an age of 23-57 years (mean, 35 years); and the length of the bone defect was 5-12 cm (mean, 8 cm). The cause of injury was mechanical injury in 2 cases and strangulation in 3 cases. All of them were the open fracture of Gustilo type Ⅲ. There were 2 cases of radial fracture, 1 case of cubital nerve injury, and 3 cases of radial nerve injury. The time from injury to one-stage operation was 6-18 hours (mean, 10 hours). The operation time, intraoperative blood loss, and intraoperative fluoroscopy were recorded. During follow-up, the anteroposterior and lateral X-ray films of the elbow joints were performed to identify whether there was prosthesis loosening; Mayo Elbow Performance Score (MEPS) and upper extremity Enneking score were used to evaluate limb function.ResultsThe operation time was 140-190 minutes (mean, 165 minutes). The intraoperative blood loss was 310-490 mL (mean, 415 mL). The intraoperative fluoroscopy was 1-3 times (mean, 1.6 times). Five patients were followed up 14-38 months (mean, 21 months). The wound exudate occurred in 1 case and cured after anti-inflammatory local dressing change; the subcutaneous hematoma occurred in 1 case, and improved after color Doppler ultrasound guided puncture and drainage. The MEPS scores and the Enneking scores were all significantly improved when compared with preoperative ones (P<0.05). Except MEPS score between 6 and 12 months after operation had no significant difference (P>0.05), there were significant differences in MEPS scores and Enneking scores between the other time points (P<0.05). During the follow-up, no prosthetic loosening or joint dislocation occurred.Conclusion3D printing technology can achieve personalized treatment of severe distal humeral bone defects, obtain relatively good elbow joint function, and has less postoperative complications and satisfactory effectiveness.
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.
ObjectiveTo review research progress on the design, manufacturing, and clinical application of three-dimensional (3D) printed customized prosthesis in acetabular reconstruction of hip revision surgery. MethodsThe related research literature on 3D printed customized prosthesis and its application in acetabular reconstruction of hip revision surgery was searched by key words of “3D printed customized prosthesis”, “revision hip arthroplasty”, “acetabular bone defect”, and “acetabular reconstruction” between January 2013 and May 2024 in Chinese and English databases, such as CNKI, Wanfang database, PubMed, etc. A total of 34 271 articles were included. After reading the literature titles, abstracts, or full texts, the literature of unrelated, repetitive, low-quality, and low evidence level was screened out, and a total of 48 articles were finally included for analysis and summary. ResultsThe bone growth and mechanical properties of 3D printed customized prosthesis materials are better than those of non-3D printed customized prosthesis, which further solves the problem of elastic modulus mismatch between the implant and natural bone caused by “stress shielding”; the porous structure and antibacterial coating on the surface of 3D printed customized prosthesis have good anti-bacterial effect. 3D printed customized prosthesis can perfectly match the patient’s individual acetabular anatomical characteristics and defect type, thus improving the accuracy of acetabular reconstruction and reducing the surgical time and trauma. Conclusion3D printed customized prosthesis can be used for precise and efficient individualized acetabular reconstruction in hip revision surgery with good early- and mid-term effectiveness. More optimized production technics and procedures need to be developed to improve the efficiency of clinical application and long-term effectiveness.