Influence of the Different Prosthesis Designs on Subjective Functional Evaluation after TKA: Medium-Term Outcome Using the 2011 Knee Society Score

Background: Patient-reported outcome (PRO) has become the focus of increased attention in the assessment of total knee arthroplasty (TKA). The purpose of this study was to investigate whether different prosthesis designs affected postoperative patient-reported performance. Materials and Methods: We reviewed 216 patients (234 knees) implanted with the Press-Fit Condylar Sigma prosthesis at our institution between January 2009 and December 2011. This study included 76 knees with fixed-bearing cruciate-retaining (FB-CR), 78 knees with fixed-bearing posterior-stabilized (FB-PS), and 80 knees with mobile-bearing posterior-stabilized (MB-PS) designs. The mean follow-up was 8.0 ± 0.74 years. Preoperative and follow-up ratings according to the 2011 Knee Society Score (2011 KSS), range of motion (ROM), and standing femoro-tibial angle (FTA) were obtained for all patients. Additionally, Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were collected at last follow-up. Results: Three separate subscales of the 2011 KSS of the three cohorts were significantly improved post-operatively compared to the pre-operative values (p < 0.05), except for expectation scores. At the time of follow-up, significantly higher the 2011 Knee Society Functional Scores <2011 KSFS> (P = 0.016) were found in the PS group. In particular, there were significant differences in advanced activities of the 2011 KSFS among the three groups (P = 0.017). Satisfaction scores showed no difference among the three groups (P = 0.251). On the other hand, WOMAC and expectation scores were significantly better in the PS groups. (P = 0.003, P = 0.004). ROM in the MB-PS group (124.0°) was better than that in FB-PS (119.4°) and FB-CR (118.9°) (P = 0.005). On the other hand, additional surgery was needed in five PS knees. Conclusion: The PS prostheses had superior 2011 KSFS, expectation scores, WOMAC scores and ROM than the CR prostheses. In contrast, the postoperative prosthesis-related complication rates were lower with CR prostheses. Further detailed evaluation is necessary to determine whether the characteristics of the different prostheses affect PRO.

THE DESIGN AND CLINICAL APPLICATION OF TOTALANKLE PROSTHESIS WITH PARTIAL TIBIA

The authors applied the first total ankle with partial tibial replacement forthe tumor of the tibia and fibula in 1987. We have followed this case for 10 years.Up to now, the outcome of this operation is very good, with no tumor recurrenceand good function. According to the experiences, the authors raised the technicalindexes of design, the indications, incision, surgical procedures, and warnings.

Development and application of rapid rehabilitation system for reconstruction of maxillofacial soft-tissue defects related to war and traumatic injuries

Background: Maxillofacial war injuries usually cause severe facial organ defects and deformities, handicapping the patient's daily activities, even result in a tendency to commit suicide. The application of maxillofacial prosthesis is an alternative to surgery in functional–aesthetic facial reconstruction. Computer aided design and computer aided manufacturing has opened up a new approach to the fabrication of maxillofacial prosthesis. An intelligentized rapid simulative design and manufacture system for prosthesis was developed to facilitate the prosthesis fabrication procedure.Methods: Maxillofacial prosthesis rapid simulation design and rapid fabrication system consists of three components: digital impression, intelligentized prosthesis designing, and rapid manufacturing. The patients' maxillofacial digital impressions were taken with Structured-light 3D scanner; and then the 3D model of prostheses and their negative molds could be designed in specific software; finally, with the resin molds fabricated by rapid prototyping machine, the prostheses could be produced directly and quickly.Results: Fifteen patients of maxillofacial defect caused by traumatic injuries received prosthesis rehabilitation provided by the established system. The contour of the prostheses coordinated properly with the appearance of the patients, and the uniform-thickness border sealed well to adjacent tissues. All the patients were satisfied with their prostheses.Conclusions: The rapid simulative rehabilitation system of maxillofacial defects has been approaching completion. It could provide advanced technological reservation for the Army in the issue of maxillofacial defect rehabilitation.

Use of short stems in revision of standard femoral stem:A case report

BACKGROUND Short stems are usually uncemented prosthetics and are recommended in the treatment of traumatic or degenerative diseases of hip.In revision procedures for elderly patients with serious comorbidity,applying a short stem could reduce peri-and post-operative secondary surgical risks to femoral osteotomy,which are necessary for the removal of parts of the implant or acrylic cement from the medullary canal.There are no cases in the literature that apply a short stem for prosthetic revision by acrylic cement anchorage.CASE SUMMARY A male patient had a left hip replacement in 1995 due to coxarthrosis.At the age of eighty the patient reported an accidental trauma and walked with pain in the left thigh.The X-ray highlighted the stem breakage in the distal section without fracturing the femoral cortex.The patient had various comorbidities(diabetes,anaemia,heart deficiency,and arrhythmia)presenting a high operation risk(ASA 4).During the revision procedure,the distal apex of the stem could not be removed from the femoral cortex.Because of the poor general health of the patient,the surgeon decided not to perform a Wagner femoral osteotomy to remove the distal section of the stem and decided to implant a short stem to avoid removing the stem section of the previous implant.The patient had his left femur X-rayed 15 d post-trauma.CONCLUSION A field of application of short stem may be the development of a cemented short stem to reduce the complexity of the revision procedure.

Systematic review of the etiology behind patellar clunk syndrome

BACKGROUND Total knee arthroplasty is one of the most successful operations performed worldwide today.Patellar clunk syndrome(PCS)is a postoperative complication that arises due to the development of a fibrous nodule along the undersurface of the quadriceps tendon.The current literature on PCS has not yet come to a consensus regarding its etiology.To date,this is the first study that analyzes the existing literature on PCS in order to generate a conclusion regarding its etiology.It is hypothesized that prosthesis design is the main component behind the development of PCS.AIM To determine the etiology of PCS and its association with pre and post-operative characteristics of the prosthesis and native knee.METHODS We conducted a systematic review according to the PRISMA guidelines by searching through PubMed,Cochrane,and Google Scholar from May-July 2018 for cases of PCS using search MeSH terms“patella OR patellar”AND“clunk”OR“catch”OR“crepitus”.The search included case series and clinical trials and excluded review articles,yielding 30 articles from the original search and 3 additional articles from reference lists.We extracted data upon the outcomes in patients afflicted with PCS to determine the etiology of PCS.We performed additional bias assessments to validate our search algorithm and results.RESULTS Prosthesis design was the metric most frequently implicated in the incidence of PCS,though several other metrics were contributory toward its pathogenesis.Later prosthetic designs incorporate a reduced intercondylar box ratio and box width to reduce contact between the proximal patellar pole and the intercondylar box,thereby reducing incidence of PCS.CONCLUSION The etiology of PCS is multifactorial,owing to the growing metrics that have associations with its incidence.This conclusion is validated by the significance of prosthesis design as the most likely parameter involved in developing PCS since different prosthesis designs are often the result of different parameters.Future studies should be directed at isolating individual prosthetic parameters of prosthesis designs in order to determine what permutation of parameters is most closely associated with the development of PCS.

Novel 3D Printed Modular Hemipelvic Prosthesis for Successful Hemipelvic Arthroplasty： A Case Study

In this study, in order to prevent the failure of hemipelvic arthroplasty using a patient-specific Computer-Aided Design （CAD） and Additive Manufacturing （AM） approach, a new design for modular hemipelvic prosthesis was developed. Moreover, the biomechanical properties of the new design were determined. The 3D printed pelvic prosthesis with a sacrum portion that completely matches the back surface of the patient＇s sacrum offers more potential for bone ingrowth between the host bone and prosthesis. The new approach integrated the capabilities of digital medical imaging techniques, CAD and metal AM to realize a modular hemipelvic prosthesis. The patient＇s pelvic Digital Imaging and Communication in Medicine （DICOM） data were imported into Mimics software to construct a digital representative patient model for design of the prosthesis. A physical model was obtained using a Stereolithography （SLA） 3D printer for preoperative planning. The final customized implant was designed by using UG NX 10.0 software. Then a surgically modular hemipelvic prosthesis was fabricated from the Ti6Al4V titanium alloy by electron beam melting technology. The operation was performed according to the preoperative planning. The outcome of the operation was good at the 6-month follow-up. Also, the stress distribution and the relative micromotion revealed positive results based on a finite element model built to detect prosthesis stability. The 3D printed modular hemipelvic prosthesis provided good resolution for the failure of hemipelvic arthroplasty. Personal customization will be important in future surgeries aiming at improving the anatomy and function of the implant.

Three-fin acetabular prosthesis for superior acetabular bone defects： a three-dimensional finite element analysis

Background Given that three-dimensional finite element models have been successfully used to analyze biomechanics in orthopedics-related research, this study aimed to establish a finite element model of the pelvic bone and three-fin acetabular component and evaluate biomechanical changes in this model after implantation of a three-fin acetabular prosthesis in a superior segmental bone defect of the acetabulum.

Does mismatch of the femoral component aspect ratio influence the range of knee flexion after posterior-stabi- lized total knee arthroplasty？

Objective： To study whether the range of knee flexion （ROF） is affected by geometrical mismatch of the femoral component and the resultant change in the pos- terior condylar offset （PCO） after high-flexion posterior-sta- bilized total knee arthroplasty （TKA）. Methods： One hundred osteoarthritic patients （50 males and 50 females） underwent femoral osteotomy by the ante- rior referencing technique. The PCO for each patient was measured from lateral radiographs before, during and 2 years after TKA. The thickness of the joint cartilage was mea- sured by magnetic resonance imaging before TKA and added onto the radiographic measurement. The relationship between changes in the PCO and improvements in the ROF before, during and 2 years after TKA were statistically analyzed. Results： Compared with the preoperative value, the PCO was reduced by （3.45±3.28） mm after TKA, with a significantly larger reduction observed in female patients than male patients （P〈0.05）. When examining the subject popu- lation as a whole, there was a significant positive correla- tion between PCO and ROF improvement during TKA （P〈 0.05）, but this improvement was not maintained 2 years after TKA （P〉0.05）. However, when male and female patients were analyzed separately, there was a significant positive correlation between PCO change and ROF improvement for both sexes at both time points （all P〈0.05）. Conclusions： Restoration of PCO plays an important role in the optimization of knee flexion even after posteriorstabilized TKA. Femoral components based on Caucasian anatomic characteristics could not match the native anatomy of distal femurs in Chinese population especially female Chinese. Rotated resection of distal femur with anterior referencing technique usually leads to a decreased PCO and therefore reduces maximal obtainable flexion.

Role of precoating in artificial vessel endothelialization

As the progress of vascular surgery, artificial vessels have become the substitute for large and middle diameter vessels but have not for small diameter ones owing to thrombogenesis and occlusion within a short period of time after being applied. Artificial vessel endothelialization is one of the ideal methods to resolve such issue and has been improved continuously since Herring in 1978 put forward this term in the first time and utilized vascular endothelial cells (ECs) harvested from living animals to perform the test of artificial vessel endothelialization. However, human endothelial cells show little adhesion to the currently available vascular graft materials and some expanded polytetrafluoroethylene (ePTFE) grafts have shown only 10%+/-7% endothelial cell attachment rate (ECA, ie, attachment of ECs when incubated in vitro). Moreover, when the graft is exposed to pulsatile blood flow, a high proportion of cells are washed off from the lumen. Maximum cell loss occurs in the first 30-45 min after exposure to pulsatile flow, with up to 70% of cells lost. After that, a slower exponential loss occurs over the next 24 h. The lack of retention of cells could be partly overcome by sodding, but other techniques, involving engineering the lumen to improve ECA and endothelial cell retention rate (ECR, ie, retention of ECs when the grafts are exposed to pulsatile flow) have been developed. These include shear stress preconditioning, electrostatic charging and, above all, most successfully to date, precoating with EC specific adhesive glues that are mostly found in the extracellular basement membrane of blood vessels. The commonest are chemical coatings, preclotting, chemical bonding, and surface modifications.