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 discuss the clinical application of preserving femoral neck in total hip arthroplasty and to analyze the early stage results.Methods From January 1999 to June 2001, 12 patients underwent total hip arthroplasty with preservation of femoral neck. We cut off the femoral head in infra-head position with improved Moore micro-incisions to reserve intact neck of femur. Thensuitable size of extra cup was selected and placed at 55° eversion angle. The internal cup, made from ultra high polymer poly thene and with ultra radius design, was placed at 45°eversion angle. Harris scores were recorded before operation, after operation and during the follow-up. During the follow-up, the X-rayfilms were taken to assess position, loosening of the prosthesis and ectopic ossification.Results All 12 patients were followed up 2-4.5years with an average of 3.1 years. The mean Harris score of hip elevated from 54 scores before operation to 92 scores of the last follow-up. Mild ectopic ossification occurred in 3 cases. There was no prosthesis loosening and femoral prosthesis setting, and only onepatient had mild bone absorption around femoral prosthesis.Conclusion Total hip arthroplasty with femoral neck preservation is a good option for the patients who need total hip arthroplasty for variable reasons, which is indicated for the patients whose femoral neck is intact with no osteoporosis.
ObjectiveTo evaluate long-term radiographic and clinical effectiveness of total cervical disc replacement (TDR) with Prodisc-C prosthesis at a minimum of 10 years follow-up.MethodsThe clinical data of 118 patients with cervical disc degeneration disease (CDDD) treated with TDR by using Prodisc-C prosthesis between December 2005 and April 2008 were retrospectively analyzed. There were 66 males and 52 females, with the age of 25-62 years (mean, 46.8 years). There were 38 cases of cervical spondylotic radiculopathy, 28 cases of cervical spondylotic myelopathy, and 52 cases of mixed cervical spondylotic myelopathy. The operative segments were C3-7, including 90 cases of single segment, 20 cases of continuous double segments, and 8 cases of continuous three segments. A total of 154 Prodisc-C prostheses were used during the operation. The clinical effectiveness was evaluated by pain visual analogue scale (VAS) score, neck disability index (NDI), Japanese Orthopaedic Association (JOA) score, and Odom grade before and after operation. Imaging evaluation indicators included range of motion (ROM), sagittal lordosis angle, intervertebral disc height (IDH), and prosthesis displacement, subsidence, loosening, locking, and heterotopic ossification (HO), adjacent segment degeneration (ASD), and other complications. Patients were grouped according to whether HO or ASD occurred or not, the ROM of surgical segment was compared.ResultsAll patients were followed up 121-150 months (mean, 135.8 months). No revision operation was performed during the follow-up period. The VAS, NDI, JOA scores and Odom grades were significantly improved at 1 week after operation and last follow-up when compared with preoperative ones (P<0.05); VAS and NDI scores were further improved at last follow-up than those at 1 week after operation (P<0.05); there was no significant difference in JOA scores and improvement rates between at 1 week after operation and at last follow-up (P>0.05). The ROM of the whole cervical spine and the operative segment decreased at 1 week and 10 years after operation when compared with preoperative ones (P<0.05), but there was no significant difference in the other time points (P>0.05); there was no significant difference in the ROM between the upper adjacent segment (UAS) and the lower adjacent segment (LAS) at each time point after operation (P>0.05). There was no significant difference in sagittal lordosis angle of cervical spine before and after operation (P>0.05); the sagittal lordosis angle of operative segment increased significantly at 1 week, 6 months, 1 year, and 2 years after operation (P<0.05). The IDH of operative segment was significantly improved at each time point after operation (P<0.05), but there was no significant difference in IDH between UAS and LAS at each time point after operation (P>0.05). No prosthesis displacement, subsidence, or loosening occurred at each time point after operation. There was no significant difference of the prosthetic displacement and subsidence distance between all time points after 6 months after operation (P>0.05). At last follow-up, the incidence of prosthetic locking/fusion was 10.4%, showing no significant difference when compared with 6 months (1.9%) (P<0.05). The incidence of upper ASD and lower ASD was 1.3% and 2.6% respectively at 1 week after operation. The incidence of upper ASD and lower ASD increased gradually with time prolonging, and there were significant differences between different time points (P<0.05). The ROM of operative segment in ASD group was lower than that in non-ASD group at each time point after operation, but there was no significant difference (P>0.05). HO appeared in 58.4% of the segments at 6 months after operation, and the incidence of HO increased significantly with time, which was significantly different from that at 6 months after operation (P<0.05). The ROM of operative segments in HO group was significantly lower than that in non-HO group at 6 months, 2 years, 5 years, and 10 years after operation (P<0.05).ConclusionTDR has little effect on adjacent segments, although there are some imaging complications, it has no significant effect on the improvement of overall clinical effectiveness. Prodisc-C prosthesis can provide long-term, safe, and definite clinical effectiveness in the treatment of CDDD.
Objective To investigate the effectiveness of cementless total hip arthroplasty (THA) in treatment of avascular necrosis of the femoral head (ANFH) in patients with human immunodeficiency virus (HIV) infection. Methods The clinical data of 22 patients (35 hips) with HIV infection and ANFH (positive group), who were treated with cementless THA between February 2014 and January 2017, was retrospectively analyzed. Tirty-three cases (43 hips) without HIV infection, who were treated with cementless THA during the same period, were collected as control (negative group). There were significant differences in the age, gender, incidence of bilateral ANFH, and disease duration between 2 groups (P<0.05). There was no significant difference in the Ficat stage of ANFH between 2 groups (P>0.05). The operation time, intraoperative blood loss, rate of blood transfusion, postoperative complications, and hospitalization time were recorded. The hip joint function was evaluated by Harris score and X-ray film was performed to observe the position of the prosthesis. Results The follow-up time was 13-24 months (mean, 20.2 months) in positive group and 14-25 months (mean, 21.6 months) in negative group. The operation time of negative group was significantly shorter than that of positive group (t=3.677, P=0.001). However, there was no significant difference in intraoperative blood loss, rate of blood transfusion, and hospitalization time between 2 groups (P>0.05). There was no significant difference in Harris score between 2 groups before operation and at 1, 3, 6, and 12 months after operation (P>0.05). There were 2 cases of superficial infection of incision and 1 case of pulmonary infection during hospitalization in positive group, and 1 case of superficial infection of incision and 1 case of venous thrombosis of lower extremity in negative group. No death or loosening and sinking of the prosthesis occurred in both groups during follow-up. Conclusion Cementless THA is a safe and effective method for ANFH in patients with HIV infection.
Objective To evaluate the clinical valueof the revision of total hip replacement(THR), to analyse the reason of the rev isions, and to discuss the main difficulties and measures to manage it.Methods From June 1998 to January 2002, 15 cases (15 hips) were revised on totalhip replacement. The reasons for revision in the cases were as follows:failure of primary operative techenique, loosening and sinking of the components, displacement of the prosthesis, erosion of the acetabulum, as well as fracture of the femoral stem. The main difficulties of the revision were:poor health condition of the patients; the remove of the prosthesis of the primary THR,especially the broken femoral stem and the cements; the loss of localbone. The measures to remove the broken femoral stem were described.ResultsAll cases were followed up 2.4 years on average: 2 patients died from heart disease and cerebrovascular disease respectively, while the good results were achieved in the others.No infection, dislocation, loosening, and other complications occurred. The good effects were related with following factors:mild degree of illness; no severe bone defect; most of the first femoral head replacement.Conclusion The revision of THRis a more difficult operation, so that the special instrument and equipment andoperative experience are required.
Objective To summarize the application progress of three-dimensional (3D) printed metal prosthesis in joint surgery. Methods The related literature was extensively reviewed. The effectiveness of 3D printed metal prosthesis in treatment of joint surgery diseases were discussed and summarized, including the all key issues in prosthesis transplantation such as prosthesis stability, postoperative complications, bone ingrowth, etc. Results 3D printed metal prosthesis has good matching degree, can accurately reconstruct and restore joint function, reduce operation time, and achieve high patient satisfaction in short- and medium-term follow-up. Its application in joint surgery has made good progress. Conclusion The personalized microporous structure prostheses of different shapes produced by 3D printing can solve the problem of poor personalized matching of joints for special patients existing in traditional prostheses. Therefore, 3D printing technology is full of hope and will bring great potential to the reform of orthopedic practice in the future.
Objective To introduce the concept and clinical applications of rotational alignment of the femoral prosthesis in total knee arthroplasty (TKA) so as to avoide the postoperative complications caused by rotational alignment. Methods The clinical and experimental research literature about rotational alignment of the femoral prosthesis in TKA was extensively reviewed and analyzed. Results Femoral prosthesis malrotation can lead to flexion gap unbalanced and undesirable patellar track. Rotation alignment of the femoral prosthesis is defined with radiological and computer assisted technique at pre- and post-operation, which can make the rotation alignment of the femoral prosthesis and the function of the knee favorable. Conclusion In recent years, many surgical skills and new techniques of defining the rotational alignment are developed, and good clinical results are achieved.
ObjectiveTo report the preliminary clinical results and analyze the prognostic factors of prosthetic failures with non-cemented modular prosthetic reconstruction after tumor resection in lower extremities.MethodsA clinical data of 150 patients with lower extremity tumors treated with MEGASYSTEM-C non-cemented modular prosthetic reconstruction between October 2011 and September 2016 was retrospectively analyzed. There were 88 males and 62 females, aged from 12 to 81 years, with a median age of 24 years. According to World Health Organization (WHO) classification of bone tumors, 120 cases were primary malignant tumors, 27 cases were intermediate tumors, and 3 cases were metastatic tumors. Among them, 134 cases underwent primary operation and 16 cases underwent reoperation after recurrence. Eighty-seven patients with malignant tumors received chemotherapy before and after operation, and no patient received local radiotherapy during perioperative period. Proximal femur was reconstructed in 32 cases, distal femur in 83 cases, and proximal tibia in 35 cases. The postoperative follow-up time, the results of oncology (survival status and tumor recurrence), and prosthesis failure (prosthesis survival rate, reasons for failure, treatment plan after failure) were recorded. The reason of the prosthesis failure was classified into 5 types according to the classification defined by Henderson et al. Kaplan-Meier survival analysis and Log-Rank test were used to analyze patient and prosthesis survival. Lower extremity function was assessed by using the Musculoskeletal Tumor Society (MSTS) scoring system and MSTS scores were compared for patients with different reconstruction sites.ResultsAll patients were followed up 5-84 months, the median follow-up time was 39 months. During the follow-up period, there were 116 cases of tumor-free survival, 10 cases of tumor-bearing survival, and 24 died of lung metastasis or multiple metastases. The 3-year and 5-year survival rates of 120 patients with primary malignant tumors were 83.1% and 76.6%. There was no significant difference in survival rate between different reconstruction sites (P=0.851). Seven cases (4.7%) had local recurrence at 7-21 months after operation. The 3-year and 5-year survival rates of the prosthesis in 150 patients were 94.4% and 92.5%. There was no significant difference in survival rate between different reconstruction sites (P=0.765). There were 26 failures in 24 patients (16.0%) during the follow-up period. There were 9 cases of type 1 failure, 1 case of type 2 failure, 3 cases of type 3 failure, 5 cases of type 4 failure, and 8 cases of type 5 failure. At last follow-up, 120 of the 126 patients survived without prosthetic failure. Except that the influence of different parts of prosthesis on the incidence of type 4 failure (P=0.029), the influence of chemotherapy on the incidence of type 5 failure (P=0.002) were significant, the influence of other types of failure on different reconstructed parts of prosthesis, initial operation, and perioperative chemotherapy had no significant difference (P>0.05). There were 5 cases of amputation (4 cases of type 5 failure, 1 case of type 4 failure), 3 cases of prosthesis removal (1 case of type 2 failure, 1 case of type 3 failure, 1 case of type 4 failure), 3 cases of revision while keeping the original prosthesis (2 cases of type 1 failure, 1 case of type 5 failure). The overall MSTS score was 24±3. The MSTS scores were 24±3, 25±3, and 23±3 in patients whose reconstruction sites located in proximal femur, distal femur, and proximal tibia, respectively, showing no significant difference (F=3.014, P=0.052).ConclusionThe short-term follow-up showed a lower incidence of complications and good function for MEGASYSTEM-C non-cement modular prosthesis system in treatment of bone defects after lower limb tumor resection. The main factors affecting the early survival of prosthesis were tumor progression and infection.
Objective To investigate and evaluate the safety and efficacy of the aortic-mitral annular enlargement technique (double annular enlargement) in patients with small-size valve prostheses after prior valve surgery. MethodsThe clinical data of patients who underwent double valve annular enlargement in Wuhan Asia Heart Hospital from April 2020 to April 2022 were retrospectively analyzed. Results A total of 30 patients were collected, including 2 males and 28 females aged 9-78 (52.71±3.53) years. All patients had previous heart valve surgery, including 1 patient receiving the third heart surgery. All patients were operated on successfully and there were no postoperative in-hospital deaths. There was no postoperative bleeding which needed a secondary open-chest hemostasis, and one patient underwent permanent pacemaker implantation due to postoperative sick sinus syndrome. The mean diameter of the implanted prosthetic aortic valve was 24.23±1.60 mm, which was significantly larger than that of the preoperative aortic valve (21.03±1.90 mm, P＜0.001). The mean diameter of the implanted prosthetic mitral valve was 28.33±1.21 mm, which was significantly larger than that of the preoperative mitral valve (25.43±0.84 mm, P＜0.001). The mean peak gradient difference across the prosthetic aortic valve on postoperative echocardiography was 18.17±6.44 mm Hg, which was significantly lower than that of the preoperative aortic valve (82.57±24.48 mm Hg, P＜0.001). The mean peak gradient difference of the postoperative prosthetic mitral valve was 12.73±5.45 mm Hg, which was significantly lower than that of the preoperative mitral valve (19.43±8.97 mm Hg, P=0.003). Conclusion The double annular enlargement technique is safe and effective for reoperation in patients with a history of valve surgery with a small aortic root to obtain both a larger size prosthetic valve for a larger orifice area and stability of the mitral-aortic valve union, resulting in good postoperative hemodynamic characteristics and clinical outcomes.
This study evaluated the cytotoxicity of a new type silicone rubber for maxillofacial prosthesis, which was developed by the present authors. According to the GB/T16886.5-2003, the samples were prepared and tested with cell counting kit-8 (CCK-8) assay, the relative growth rate (RGR) was calculated, and morphology of L929 cells were observed by scanning electron microscope and phase contrast microscope. The results showed that RGR of L929 cells were 91.65% (24 h), 87.03% (48 h), 87.30% (72 h), respectively, and the level of cytotoxicity was grade 1. The L929 cells showed typical fusiform shape and their morphology did not changed significantly after 24 h, 48 h and 72 h. These data indicated that the newly-developed silicone rubber material, as a maxillofacial prosthesis material, should be a safe biomaterial.