Indication and surgical approach for reconstruction with endoprosthesis in bone-associated soft tissue sarcomas:Appropriate case management is vital

It is important for surgeons performing sarcoma surgery to know that bone resection and tumor prosthesis applications in soft tissue sarcomas(STS)have unique features in terms of indication,surgical approach and follow-up,in terms of the management of these cases.Some STS are associated with bone and major neurovascular structures.Bone-associated STS are generally relatively large and relatively deep-seated.Additionally,the tendency for metastasis is high.In some cases,the decision about which structures to resect is difficult.These cases are often accompanied by poor oncological and surgical outcomes.Management of cases should be done by a multidisciplinary team in advanced centers specialized in this field.The surgical team must have sufficient knowledge and experience in the field of limb-sparing surgery.Preoperative evaluation and especially good planning of bone and soft tissue reconstruction are vital.

Transfer film effects induced by 3D-printed polyether-ether-ketone with excellent tribological properties for joint prosthesis

Based on the building principle of additive manufacturing,printing orientation mainly determines the tribological properties of joint prostheses.In this study,we created a polyether-ether-ketone(PEEK)joint prosthesis using fused filament fabrication and investigated the effects of printing orientation on its tribological properties using a pin-on-plate tribometer in 25% newborn calf serum.An ultrahigh molecular weight polyethylene transfer film is formed on the surface of PEEK due to the mechanical capture of wear debris by the 3D-printed groove morphology,which is significantly impacted by the printing orientation of PEEK.When the printing orientation was parallel to the sliding direction of friction,the number and size of the transfer film increased due to higher steady stress.This transfer film protected the matrix and reduced the friction coefficient and wear rate of friction pairs by 39.13%and 74.33%,respectively.Furthermore,our findings provide a novel perspective regarding the role of printing orientation in designing knee prostheses,facilitating its practical applications.

Effect of Wearing a Maxillofacial Prosthesis on Masticatory Rhythm Improvement in Mandibulectomy Patients

Background: Recording jaw movement rhythms in patients with jaw defects is challenging using conventional tracking devices. However, masticatory rhythm is crucial for masticatory performance and nutritional intake. This study aimed to explore the impact of using a maxillofacial prosthesis to restore masticatory rhythm in mandibulectomy patients with a novel wearable device. Methods: Twelve patients who underwent mandibulectomy and were rehabilitated with maxillofacial prosthesis were recruited. Chewing rate, cycle durations, coefficient of variation of cycle durations (CV), changing times of skin morphology on the back of the ear pinna area (SM), and masticatory performance were measured during gum chewing without and with a denture using a wearable jaw movement rhythm tracking device. A paired t-test and the Pearson correlation coefficient were used for statistical analysis. Results: The chewing rate increased by 8.6 cycles/min with dentures (P P = 0.01). The CV and SM decreased with dentures (P = 0.004 and P = 0.01, respectively). Significant correlations were found between the CV and SM without dentures (P = 0.004). Conclusion: 1. Wearing maxillofacial prostheses can improve masticatory rhythm in patients who undergo mandibulectomy with Eichner B2 occlusal supports. 2. The wearable device is available for measuring masticatory rhythm in patients with jaw defects in clinics. 3. Changing times of the skin morphology on the back of the ear pinna indicate jaw movement stability through a simpler process than the coefficient of variation of cycle durations.

Electrophysiological evaluation of alterations in penile sensation due to penile prosthesis implantation in patients with erectile dysfunction

Objective The present study was aimed to determine the effect of penile prosthesis implantation(PPI)surgery on penile sensation by evaluating the penile electromyography(EMG)variables.Methods The research was designed as a prospective study.Thirty patients who were diagnosed with organic erectile dysfunction and had underwent PPI surgery between January 2017 and January 2018 in the Urology Clinic of Antalya Training and Research Hospital were included in this study.Penile sensory EMG was performed on each patient 1 day prior to the surgery by the Physical Therapy and Rehabilitation clinic.Additionally,the control EMG study was also performed in the 3rd and 6th postoperative months.Results We included 27 patients in this study who attended regular follow-ups and had complete EMG results.Out of the 27 patients,23(85.2%)patients had received malleable(ProMedon)penile prosthesis,one(3.7%)patient had received a two-piece inflatable(Ambicor)penile prosthesis,and three(11.1%)patients had received a three-piece inflatable(AMS 700 CXR)penile prosthesis.The mean nerve conduction value(NCV)of the patients was 29.85(standard derivation:22.54;range:0-78.4)m/s during the preoperative period,whereas it was 27.64(standard derivation:24.72;range:0-83.3)m/s in the 3rd postoperative month and 24.80(standard derivation:22.31;range:0-88.4)m/s in the 6th postoperative month.There was no significant difference between preoperative NCV and 3rd postoperative month NCV(p=0.607).Similarly,no significant difference was observed between preoperative NCV and 6th postoperative month NCV(p=0.276).Additionally,the change between NCV values at postoperative 3rd and 6th months was not statistically significant(p=0.553).Conclusion Significant loss of penile sensation does not occur in patients who undergo PPI surgery.

A new passive transfemoral prosthesis mechanism based on 3R36 knee and ESAR foot providing walking and squatting

Researchers have proposed various linkage mechanisms to connect knee and ankle joints for above-knee prosthe-ses,but most of them only offer natural walking.However,studies have shown that people assume a squatting posture during daily activities.This paper introduces a novel mechanism that connects the knee joint with the foot-ankle joint to enable both squatting and walking.The prosthetic knee used is the well-known 3R36,while the energy storing and return(ESAR)prosthetic foot is used for the ankle-foot joint.To coordinate knee and ankle joint movements,a six-bar linkage mechanism structure is proposed.Simulation results demonstrate that the proposed modular transfemoral prosthesis accurately mimics the motion patterns of a natural human leg during walking and squatting.For instance,the prosthesis allows a total knee flexion of more than 140°during squatting.The new prosthesis design also incorporates energy-storing mechanisms to reduce energy expenditure during walking for amputees.

Gait Analysis of a Subject with Tarsometatarsal Prosthesis

Introduction: Gait analysis of an adult man after trans-metatarsal unilateral amputation is described. Objective: Instrumental gait analysis of a subject 15 years after trans-metatarsal unilateral amputation in two footwear conditions: while walking barefoot and with prosthesis. Materials and Methods: In a movement analysis laboratory, locomotion studies were carried out at freely chosen walking speed by a 65-year-old subject, obtaining kinematic, kinetic and surface electromyographic data in time and space. Gait analysis was performed using instrumental technologies from a digital eco-system applying walking protocols. Results: When the patient wore the prosthesis, several positive improvements were observed in various aspects of gait. These included enhancements in the base of support, gait speed, and joint range of movements. Additionally, there was a slight improvement in the vertical ground reaction forces pattern, indicating a positive effect of the assistive technology. Furthermore, the use of the prosthesis led to a more organized pattern of muscle activity, which further supports its beneficial impact. However, it is worth noting that some challenges still persisted, particularly regarding stabilizing the body during the double support phase. Despite this difficulty, the overall findings suggest that the use of the prosthesis offers valuable improvements to the patient’s gait dynamics. Conclusions: After conducting a thorough analysis of the parameters related to the gait of a subject who underwent a trans-metatarsal unilateral amputation fifteen years ago, it was found that the use of prosthesis had a positive impact. This study demonstrated important improvements in some kinematic and kinetic parameters, including muscle activation patterns, indicating an increase in comfort and confidence while utilizing the prosthetic device.

Current situation and development of facial prosthesis

Facial prostheses have developed significantly in the last 10 years,especially between 2016 and 2021.This development is mainly due to the great progress made in the fields of biocompatible materials,digital technology,and three-dimensional printing technology,which provides guarantee for low allergy,high biosimulation,comfort,and satisfactory usability.Treatment teams typically consist of plastic surgeons,material experts,engineers,and computer scientists who have extensive clinical experience.These teams successfully implement an integrated,multidisciplinary model by prioritizing the reasonable expectations of both the physician and patient,leading to improved patient satisfaction and compliance with prosthetic constraints.This study aimed to review the concept,development status,existing problems,and future of facial prosthesis.

Retinal Prosthesis:A Potential Benefit for the Blind

Retinal degenerative diseases may induce the degeneration of outer retina and in turn,blindness.Nevertheless,due to the maintenance of inner retina,the coding and processing of visual neurons responses are still able to be executed naturally.Therefore,an effective retinal prosthesis device may be developed by mimicking the function of outer retina:transferring the visual light into artificial stimulus and delivering the stimulus to the retina aiming to evoke the neural responses.As two main developing directions for current retinal prosthesis,epiretinal(ER)and subretinal(SR)prosthesis are both undergoing experimental stage and possessing advantages and limitations.Further investigations in power supply,biocompatibility,etc.are still required.Additionally,suprachoroidal transretinal stimulation(STS)and neurotransmitter-induced stimulation as some other alternatives in retinal prosthesis are also considered as promising research directions,although they are not mature enough to be applied commercially,either.

Development and clinical application of a new testicular prosthesis

A new type of testicular prosthesis made of silastic with an elliptical shape to mimic a normal testis was developed by our team and submitted for patenting in China. The prosthesis was produced in different sizes to imitate the normal testis of the patient. To investigate the effects and safety of the testicular prosthesis, 20 patients receiving testicular prosthesis implantation were recruited for this study. Follow-up after 6 months revealed no complications in the patients. All the patients answered that they were satisfied with their body image and the position of the implants, 19 patients were satisfied with the size and 16 patients were satisfied with the weight. These results show that the testicular prosthesis used in this study can meet patient＇s expectations. Patients undergoing orchiectomy should be offered the option to receive a testicular prosthesis implantation. The dimensions and weight of the available prosthetic implants should be further addressed to improve patient satisfaction.

An Optoelectronic Pulse Frequency Modulation Circuit for Retinal Prosthesis

A pulse frequency modulation（PFM） circuit for retinal prosthesis,which generates electrical pulses with frequency proportional to the intensity of incident light, is presented. The fundamental characteristic of the circuit is described and analyzed. The circuit is realized in 0.6μm CMOS process,and the simulation results testify to the possibility of sub-retinal implantation.

REALIZATION OF ALGORITHM OF TOOL PATH GENERATION FOR NC MACHINING OF MOLAR PROSTHESIS

The CAD model of molar prosthesis is usually stored in standard templete library （STIr） format. A new topological structure is given based on STL format and the vertex-based entity offset algorithm is presented to realize the rapid generation of roughing/finishing tool path for molar prosthesis. Simulation results show that the proposed algorithm prossesses characteristics of excellent stabilization, fast calculation speed and high machining accuracy.

Ocular prosthesis incorporating IPS e-max press scleral veneer and a literature review on non-integrated ocular prosthesis

The article highlights a new method for the fabrication of an ocular prosthesis by the incorporation of a ceramic scleral veneer. The steps of fabrication include impression making, wax try-in, performing a “cut-back” on a selected stock eye, insertion of the IPS e-max press scleral veneer, finishing and insertion. It also includes a detailed review on non-integrated ocular prostheses.

Development of an internally braced prosthesis for total talus replacement

Total loss of talus due to trauma or avascular necrosis,for example,still remains to be a major challenge in foot and ankle surgery with severely limited treatment options.Implantation of a custom made total talar prosthesis has shown promising results so far.Most important factors for long time success are degree of congruence of articular surfaces and ligamentous stability of the ankle.Therefore,our aim was to develop an optimized custom made prosthesis for total talus replacement providing a high level of primary stability.A custom made hemiprosthesis was developed using computed tomography and magnetic resonance imaging data of the affected and contralateral talus considering the principles and technology for the development of the S.T.A.R.prosthesis(Stryker).Additionally,four eyelets for fixation of artificial ligaments were added at the correspondent footprints of the most important ligaments.Two modifications can be provided according to the clinical requirements:A tri-articular hemiprosthesis or a bi-articular hemiprosthesis combined with the tibial component of the S.T.A.R.total ankle replacement system.A feasibility study was performed using a fresh frozen human cadaver.Maximum range of motion of the ankle was measured and ligamentous stability was evaluated by use of standard X-rays after application of varus,valgus or sagittal stress with 150 N.Correct implantation of the prosthesis was technically possible via an anterior approach to the ankle and using standard instruments.Malleolar osteotomies were not required.Maximum ankle dorsiflexion and plantarflexion were measured as 22-0-28 degrees.Maximum anterior displacement of the talus was 6 mm,maximum varus tilt 3 degrees and maximum valgus tilt 2 degrees.Application of an internally braced prosthesis for total talus replacement in humans is technically feasible and might be a reasonable procedure in carefully selected cases with no better alternatives left.

Tissue Sparing Surgery and Its Relevance within Hip Prosthesis

The total hip replacement rationale, since 1960 when it was introduced by Sir Charnley, has been modified and evolved until nowadays thanks to laboratory research and clinical trials. This evolution followed a guideline whose milestones are: 1) the surgical approach and implantation technique (ex: detachment of the greater trochanter);2) to use or not to use cement;3) the evolution of materials (titanium, ceramic, x-linked polyethylene);4) the identification of the debris-disease rather than the cement-disease;5) studies focused on bone-prosthesis interaction and biological phenomena related. Between those studies, the authors consider crucial the introduction of tissue sparing surgery and femoral neck preserving rationale, concepts to which they have devoted their scientific research and clinical experience for over the last 30 years, from 1980 to nowadays.

Treatment of acute periprosthetic infections with prosthesis retention: Review of current concepts

Periprosthetic joint infection(PJI) is a devastating complication after total joint arthroplasty, occurring in approximately 1%-2% of all cases. With growing populations and increasing age, PJI will have a growing effect on health care costs. Many risk factors have been identified that increase the risk of developing PJI, including obesity, immune system deficiencies, malignancy, previous surgery of the same joint and longer operating time. Acute PJI occurs either postoperatively(4 wk to 3 mo after initial arthroplasty, depending on the classification system), or via hematogenous spreading after a period in which the prosthesis had functioned properly. Diagnosis and the choice of treatment are the cornerstones to success. Although different definitions for PJI have been used in the past, most are more or less similar and include the presence of a sinus tract, blood infection values, synovial white blood cell count, signs of infection on histopathological analysis and one ormore positive culture results. Debridement, antibiotics and implant retention(DAIR) is the primary treatment for acute PJI, and should be performed as soon as possible after the development of symptoms. Success rates differ, but most studies report success rates of around 60%-80%. Whether single or multiple debridement procedures are more successful remains unclear. The use of local antibiotics in addition to the administration of systemic antibiotic agents is also subject to debate, and its pro's and con's should be carefully considered. Systemic treatment, based on culture results, is of importance for all PJI treatments. Additionally, rifampin should be given in Staphylococcal PJIs, unless all foreign material is removed. The most important factors contributing to treatment failure are longer duration of symptoms, a longer time after initial arthroplasty, the need for more debridement procedures, the retention of exchangeable components, and PJI caused by Staphylococcus(aureus or coagulase negative). If DAIR treatment is unsuccessful, the following treatment option should be based on the patient health status and his or her expectations. For the best functional outcome, one- or two-stage revision should be performed after DAIR failure. In conclusion, DAIR is the obvious choice for treatment of acute PJI, with good success rates in selected patients.

Factors influencing utilization and satisfaction with external breast prosthesis in patients with mastectomy:A systematic review

Purpose:The aim of this study is to describe and analyse the factors which influence utilization of EBPs among breast cancer patients worldwide and particularly in China.Methods:Literature searches were conducted in Wanfang,CNKI,and PubMed databses in order to identify relevant articles published in both Chinese and English up to October 2014.The phrase“external breast prosthesis”in Chinese was used to search titles,abstracts,and key words to find articles in Wanfang and CNKI electronic databases.Synonyms and related terms for external breast prosthesis were combined and used for searches performed in PubMed.Additional references were subsequently extracted from the bibliographies of all included articles and reviews.Qualitative analysis was applied in this study rather than meta-analysis.Results:The number of relevant studies published in other countries is five times greater than the literature published in China,with most articles written by Australian scientists.Based on the existing references,reconstruction,comfort,appearance,cost,mental status,and supportive information were the main factors influencing choice of treatment options by patients.Conclusion:Six main factors influencing EBP use worldwide were identified.Although the number of breast cancer cases per year is increasing at a much higher rate in China relative to the average number globally,relevant studies on Chinese patients are lacking.Thus,further studies should be undertaken in China in order to develop effective service modalities in order to improve quality of life of patients.

Customized reconstructive prosthesis design based on topological optimization to treat severe proximal tibia defect

A novel reconstructive prosthesis was designed with topological optimization(TO)and a lattice structure to enhance biomechanical and biological properties in the proximal tibia.The biomechanical performance was validated through finite element analysis(FEA)and biomechanical tests.The tibia with inhomogeneous material properties was reconstructed according to computed tomography images,and different components were designed to simulate the operation.Minimum compliance TO subject to a volume fraction constraint combined with a graded lattice structure was utilized to redesign the prosthesis.FEA was performed to evaluate the mechanical performances of the tibia and implants after optimization,including stress,micromotion,and strain energy.The results were analyzed by paired-samples t tests,and p<0.05 was considered significant.Biomechanical testing was used to verify the tibial stresses.Compared to the original group(OG),the TO group(TOG)exhibited lower stress on the stem,and the maximum von Mises stresses were 87.2 and 53.1 MPa,respectively,a 39.1%reduction(p<0.05).Conversely,the stress and strain energy on the tibia increased in the TOG.The maximum von Mises stress values were 16.4 MPa in the OG and 22.9 MPa in the TOG with a 39.6%increase(p<0.05),and the maximum SED value was 0.026 MPa in the OG and 0.042 MPa in the TOG,corresponding to an increase of 61.5%(p<0.05).The maximum micromotions in the distal end of the stem were 135μm in the OG and 68μm in the TOG,almost a 50%reduction.The stress curves of the biomechanical test coincided well with the FEA results.The TO approach can effectively reduce the whole weight of the prosthesis and improve the biomechanical environment of the tibia.It could also pave the way for next-generation applications in orthopedics surgery.

3D printing-based drug-loaded implanted prosthesis to prevent breast cancer recurrence post-conserving surgery

Systemic chemotherapy of breast cancer is commonly delivered as a large dose and has toxic side effects.Local chemotherapy would overcome the shortcomings of systemic reconstruction and could play an important role in breast cancer surgery according to personalized demand.The application of three-dimensional(3D)printing technology makes personalized customization possible.We designed and prepared a prosthesis containing paclitaxel(PTX)and doxorubicin(DOX)microspheres(PPDM)based on 3D printing to prevent tumor recurrence and metastasis after breast conserving surgery.Polydimethysiloxane has good biocompatibility and was used as a drug carrier in this study.The average particle size of the PTX and DOX microspheres were approximately 3.1μm and 2.2μm,respectively.The drug loading of PTX and DOX microspheres was 4.2% and 2.1%,respectively.In vitro drug release studies demonstrated that the 3D-printed prosthesis loaded with PTX and DOXmicrospheres could release the drugs continuously for more than 3 weeks and thereby suppress cancer recurrence with reduced side effects.The PTX and DOX microspheres not only exerted a synergistic effect,but also achieved a good sustained release effect.In vivo evaluation showed that the PPDM could effectively inhibit breast cancer recurrence andmetastasis inmice with breast cancer.PPDM are expected to achieve postoperative chemotherapy for breast cancer and be highly efficient to prevent local breast cancer recurrence and metastasis.

Penile prosthesis implantation and tunica albuginea incision without grafting in the treatment of Peyronie＇s disease with erectile dysfunction

We evaluated penile prosthesis implantation with tunica albuginea-relaxing incisions without grafting in the treatment of Peyronie＇s disease associated with erectile dysfunction. Between April 2005 and June 2011, 62 patients underwent surgery due to severe Peyronie＇s disease associated with erectile dysfunction. Malleable and inflatable penile prostheses were inserted in 49 and 13 cases, respectively. Penile prostheses were inserted into the corpora cavernosa using the standard ventral approach. After lifting the neurovascular bundle, the tunica albuginea was incised and opened at the plaque region to correct the deformities and to lengthen the penis. Subsequently, the wide neurovascular bundle was replaced, and all incisions of the tunica albuginea were covered to prevent corporal grafting. In the median follow-up of 35 months （range 14-82 months）, the penis was completely straightened in 59 （95%） patients. Numbness of the glans, which the patients found initially upsetting, decreased or disappeared spontaneously 3-6 months later. Penile prosthesis implantation with tunica albuginea incisions is a viable alternative in the treatment of Peyronie＇s disease because the extensive dissection of the neurovascular bundle allows a good approach to the plaque and provides excellent covering of the incised tunica albuginea without additional grafting.

Prospective and long-term evaluation of erect penile length obtained with inflatable penile prosthesis to that induced by intracavernosal injection

We compared erect penile length after inflatable penile prosthesis （IPP） implantation with that induced by intracavemosal injection （ICI） before surgery. A total of 11 patients with full erections induced by ICI of 0.25 mL of Trimix （papaverine, phentolamine and prostaglandin E 1） at the time of penile color duplex Doppler ultrasonograpby were enrolled in this study. The patients subsequently underwent IPP implantation as the ultimate treatment for their erectile dysfunction （ED）. Erect penile length consequent to IPP implantation was measured at 6 weeks, 6 months and at I year after surgery. The Sexual Health Inventory for Men （SHIM） was administered before, and at 6 months and 1 year after IPP implantation. Erect penile length （mean ± s.c.） as induced by ICI was 13.2 ± 0.4 cm, whereas the lengths attained with IPP were 12.4 ± 0.3, 12.5 ± 0.3 and 12.5 ± 0.4 cm at the sixth week, sixth month and 1-year follow-ups, respectively. There were 0.83 ± 0.25, 0.75 ± 0.20 and 0.74 ± 0.15 cm decreases in erect penile length at 6 weeks, 6 months and 1 year, respectively, after IPP implantation when compared with that after ICI （P 〈 0.05）. The SHIM scores for patients reporting shorter penises were the same as those for patients without complaints at the 6-month and 1-year follow-ups （P 〉 0.05）. To our knowledge, this is the first study to objectively show a significant decrease in erect penile length after IPP implantation when compared with that after ICI. However, this decrease did not affect the effectiveness of IPP in treating ED.