Introduction Of New Implants Research Articles

Introduction of innovations in joint arthroplasty: Recommendations from the 'EFORT implant and patient safety initiative'.

With the implementation of the new MDR 2017/745 by the European Parliament, more robust clinical and pre-clinical data will be required due to a more stringent approval process. The EFORT Implant and Patient Safety Initiative WG1 'Introduction of Innovation', combined knowledge of orthopaedic surgeons, research institutes, orthopaedic device manufacturers, patient representatives and regulatory authorities to develop a comprehensive set of recommendations for the introduction of innovations in joint arthroplasty within the boundaries of MDR 2017/745. Recommendations have been developed to address key questions about pre-clinical and clinical requirements for the introduction of new implants and implant-related instrumentation with the participation of a steering group, invited by the EFORT Board in dialogue with representatives from European National Societies and Speciality Societies. Different degrees of novelty and innovation were described and agreed on in relation to when surgeons can start, using implants and implant-related instrumentation routinely. Before any clinical phase of a new implant, following the pre-market clinical investigation or the equivalent device PMCF pathway, it is a common understanding that all appropriate pre-clinical testing (regulatory mandatory and evident state of the art) - which has to be considered for a specific device - has been successfully completed. Once manufacturers receive the CE mark for a medical device, it can be used in patients routinely when a clinical investigation has been conducted to demonstrate the conformity of devices according to MDR Article 62 or full equivalence for the technical, biological and clinical characteristics has been demonstrated (MDR, Annex XIV, Part A, 3.) and a PMCF study has been initiated.

Re-revision hip replacement in peri prosthesis shaft femur fracture in operated case of cemented total hip replacement

Introduction: Revision surgery differs from original total hip replacement surgery, which is a lengthier and more difficult process. To get a satisfactory result, substantial preparation is required, as well as the use of specialised implants and instruments. Periprosthetic fractures are most commonly caused by a fall and frequently necessitate revision surgery. Most modifications will include the use of customised implants intended to compensate for compromised bone and soft tissue. Case Report: 68-year-old male with bilateral cemented total hip replacement presents with peri prosthetic shaft femur fracture in left side without DNVD which was van-couver type B2 managed with ORIF + Platting + TBW loop which eventually failed, impairing the patient's routine activity, so he came to SMIMER hospital. Management: We performed implant removal + revision total hip replacement with long stem femoral component, which failed post-operatively, therefore the patient underwent Re-revision surgery with inter locking nail femoral long stem component. During repeated follow-ups, the patient expressed satisfaction with his everyday activities. Discussion: Complication are common in revision surgery. Early management is key to rectify intra operative and post-operative complication. Periprosthetic femoral fractures after total hip replacement is a rare but feared complication. Peri prosthetic fracture is managed based on fracture pattern and stem and bone stock. Conclusion: Surgical treatment of periprosthetic fractures, thanks to the introduction of new implants for osteosynthesis and development of new stems for revision endoprostheses, helps achieve ever better results. Of major importance for choosing the treatment method is correct classification of fracture and stem stability.

Cost-Effectiveness of Peptide Enhanced Bone Graft i-Factor versus Use of Local Autologous Bone in Anterior Cervical Discectomy and Fusion Surgery.

Study DesignWe conducted decision analytical modeling using a Markov model to determine the ICER of i-factor compared to autograft in ACDF surgery.ObjectiveThe efficacy and safety of traditional anterior cervical discectomy and fusion (ACDF) surgery has improved with the introduction of new implants and compounds. Cost-effectiveness of these innovations remains an often-overlooked aspect of this effort. To evaluate the cost-effectiveness of i-FACTOR compared to autograft for patients undergoing ACDF surgery.MethodsThe patient cohort was extracted from a prospective, multicenter randomized control trial (RCT) from twenty-two North American centers. Patients randomly received either autograft (N = 154) or i-Factor (N = 165). We analyzed various real-world scenarios, including inpatient and outpatient surgical settings as well as private versus public insurances. Two primary outcome measures were assessed: cost and utility. In the base-case analysis, both health and societal system costs were evaluated. Health-related utility outcome was expressed in quality-adjusted life years (QALYs). Cost-effectiveness was expressed as an incremental cost-effectiveness ratio (ICER).ResultsIn all scenarios, i-FACTOR reduced costs within the first year by 1.4% to 2.1%. The savings proved to be incremental over time, increasing to 3.7% over an extrapolated 10 years. The ICER at 90 days was $13,333 per QALY and became negative (“dominated”) relative to the control group within one year and onwards. In a threshold sensitivity analysis, the cost of i-FACTOR could theoretically be increased 70-fold and still remain cost-effective.ConclusionThe novel i-FACTOR is not only cost-effective compared to autograft in ACDF surgery but is the dominant economic strategy.

Safety of vitamin E-infused highwall liners for routine use in primary total hip arthroplasty: single centre, short-term follow-up of 1221 cases.

Introduction of new implants should be monitored closely to capture any signs of compromising patient safety. Vitamin E infused highly-crosslinked polyethylene liners (VEPE) offer the potential for reduced wear. Highwall liners have been hypothesised to result in increased wear and potential liner fractures. The aim of this study was to determine the 3-7-year follow-up of highwall VEPE for primary total hip arthroplasty (THA), focusing on liner-related complications. We included 1221 consecutive THA operations from July 2010 to May 2014 with minimum follow-up of 3 (3.1-6.8) years Data collected included demographics, implant data, complications, reoperations, and deaths. Data were cross-referenced with the Danish Hip Arthroplasty Registry in order to ensure validity and completeness. Acetabular shell position was measured using Martell Hip Analysis Suite in a subgroup of 931 THAs. Cumulative stem revision and shell revision at 3-year follow-up was 3.4% and 0.4% respectively. There were no revisions due to liner failure. Reason for revision included 11 dislocations, 15 soft-tissue revisions for infection, 44 stem revisions of which 34 were periprosthetic fractures and 13 shell revisions of which 6 were combined shell and stem revisions. Early follow-up of VEPE liners for primary THA have not shown any revisions associated with liner failure. Continued monitoring of new materials are necessary to capture any signs of compromised patient safety.

Increased risk for dislocation after introduction of the Continuum cup system: lessons learnt from a cohort of 1,381 THRs after 1-year follow-up

Background and purpose — The introduction of new total hip replacements (THRs) is known to be associated with an increased risk for complications. On completion of a competitive procurement process, a new uncemented cup system was introduced into general use at our institution in 2016. We launched this study after the introduction to assess (1) the incidence of early dislocations of the old (Pinnacle) and the new (Continuum) cup systems, and (2) whether the cup design would affect the risk for dislocation.Patients and methods — We assessed the incidence of dislocations after 1,381 primary THRs performed at our institution during 2016. Also, the effect of the cup system (Pinnacle, Continuum with neutral liner, Continuum with elevated rim liner) on dislocation rates was analyzed using a multivariable regression model.Results — 47 (3.4%) early dislocations were identified. The incidence of dislocations was 1.3% for the Pinnacle, 5.1% for the Continuum with neutral liner, and 1.2% for the Continuum with elevated rim liner. The Continuum with neutral liner was found to have an increased risk for dislocations compared with the Pinnacle (aOR 5, 95% CI 1.4–17). However, when an elevated rim liner was used with the Continuum, the risk for dislocation between the Continuum and the Pinnacle was similar.Interpretation — Our results emphasize the need for both careful consideration before the introduction of new implants and the systematic monitoring of early outcomes thereafter. The elevated rim liner should be preferred for use with the Continuum cup because of the poor coverage of the neutral liner that may result in dislocations.

A systematic review of short metaphyseal loading cementless stems in hip arthroplasty.

Short-stemmed femoral implants have been used for total hip arthroplasty (THA) in young and active patients to conserve bone, provide physiological loading, and reduce the incidence of thigh pain. Only short- to mid-term results have been presented and there have been concerns regarding component malalignment, incorrect sizing, and subsidence. This systematic review reports clinical and radiological outcomes, complications, revision rates, and implant survival in THA using short-stemmed femoral components. A literature review was performed using the EMBASE, Medline, and Cochrane databases. Strict inclusion and exclusion criteria were used to identify studies reporting clinical and radiological follow-up for short-stemmed hip arthroplasties. A total of 28 studies were eligible for inclusion. This included 5322 hips in 4657 patients with a mean age of 59 years (13 to 94). The mean follow-up was 6.1 years (0.5 to 20). The mean Harris Hip Score improved from 46 (0 to 100) to 92 (39 to 100). The mean Oxford Hip Score improved from 25 (2 to 42.5) to 35 (12.4 to 48). The mean Western Ontario & McMaster Universities Osteoarthritis Index improved from 54 (2 to 95) to 22 (0 to 98). Components were aligned in a neutral coronal alignment in up to 90.9% of cases. A total of 15 studies reported component survivorship, which was 98.6% (92% to 100%) at a mean follow-up of 12.1 years. Short-stemmed femoral implants show similar improvement in clinical and radiological outcomes compared with conventional length implants. Only mid-term survivorship, however, is known. An abundance of short components have been developed and used commercially without staged clinical trials. Long-term survival is still unknown for many of these components. There remains tension between innovation and the moral duty to ensure that the introduction of new implants is controlled until safety and patient benefit are demonstrated. Implant innovation and subsequent use should be driven by proven clinical outcomes, rather than market and financial forces, and ethical practice must be ensured. Cite this article: Bone Joint J 2019;101-B:502-511.

A randomized RSA study concentrating especially on continuous migration

Background and purpose — There is a general call for phased introduction of new implants, and one step in the introduction is an early evaluation of micromotion. We compared the micromotion in the Triathlon and its predecessor, the Duracon total knee prosthesis, concentrating especially on continuous migration over 5 years of follow-up. Patients and methods — 60 patients were randomized to receive either a cemented Triathlon total knee prosthesis or a cemented Duracon total knee prosthesis. 3-D tibial component migration was measured by radiostereometric analysis (RSA) at 3 months and at 1, 2, and 5 years. Results — There was no statistically significant difference in maximum total point motion (MTPM) between the 2 groups (p = 0.1). The mean MTPM at 5 years for the Duracon was 1.10 (SD 1.21) mm and for the Triathlon it was 0.66 (SD 0.38) mm. The numbers of continuously migrating prostheses were similar in the groups at the fifth year of follow-up; 6 of 21 prostheses in the Duracon group and 3 of 21 in the Triathlon group had migrated more than 0.3 mm between the second year and the fifth year of follow-up (p = 0.2). Interpretation — The Triathlon has a micromotion pattern similar to that of the Duracon total knee system at both short-term and medium-term follow-up, and may therefore, over time, show the same good long-term mechanical stability.

Effects of magnesium degradation products on mesenchymal stem cell fate and osteoblastogenesis

The unique properties of magnesium (Mg) and its alloys that combine favourable mechanical properties, biocompatibility, and biodegradability, which until now have been restricted primarily to polymers, justify its study in the field of implantology. Previous in vivo studies have underlined the possible osteoconductive effects of Mg-based metals, and several in vitro studies have highlighted positive effects of Mg-enriched biomaterials. However, although the observed biological activity of magnesium is intriguing, it remains largely unexplored. Furthermore, due to increased regulations, the introduction of new implants on the market must be accompanied by thorough mechanistic understanding. Therefore, to mimic the in vivo effects of the degradation of Mg-based implants on mesenchymal stem cell differentiation during bone remodelling, non-haematopoietic multipotent foetal progenitor cells, i.e., human umbilical cord perivascular cells (HUCPV), were cultured for up to three weeks with or without osteoblastic differentiating media and with or without magnesium extract (approximately 5mM). To partially unveil the mechanism or to select paths for further investigation, a very broad selection of genes was chosen (e.g., those involved in osmolality sensing). Several classical bone markers were also studied at the gene and protein levels. The data suggest that Mg extract alone potentiates cell proliferation or delays the natural fate of maturation/differentiation. However, when the cells are driven toward osteoblastic differentiation, the effect of the Mg extract becomes much more complex, positively or negatively influencing differentiation via various pathways. These preliminary results confirm the choice of the various parameters utilised here and highzlight the importance of further studies.

Post-traumatic wrist atrhritis: PRC versus 4-corner fusion

Painful destruction of the wrist as a consequence of scaphoid non-union advanced collapse (SNAC) or chronic advanced scapho-lunate dissociation (SLAC) is a challenge to treat. In the late stages of either condition, only salvage procedures can be discussed. The option of proximal row carpectomy (PRC) only remains available in stage II, when the mid-carpal joint is still preserved and the capitate head has an intact cartilage. Four-corner fusion (4CF) is still possible in stages III of these conditions. While PRC is technically less demanding and does not involve the possibility of non-union, different postoperative problems have been described with this technique. This includes radial styloid impingement and pisiform bone impingement syndromes, leading to further interventions. In addition progressive osteoarthritis at the lunate fossa has been observed, compromising long-term results. In contrast, 4-corner fusion is a technically demanding procedure with a risk of non-union, despite the introduction of new implants. Furthermore malunion with incomplete lunate repositioning may compromise the clinical results. This study attempts to analyze the results of PRC compared to 4-corner fusion in stages II/III wrists suffering from SNAC or SLAC situations.

The next critical role of orthopedic registries

The next critical role of orthopedic registries

Appraisal of evidence base for introduction of new implants in hip and knee replacement: a systematic review of five widely used device technologies

Objective To determine the evidence of effectiveness and safety for introduction of five recent and ostensibly high value implantable devices in major joint replacement to illustrate the need for change...

Radiostereometric analysis of early implant migration – a valuable tool to ensure proper introduction of new implants

Radiostereometric analysis of early implant migration – a valuable tool to ensure proper introduction of new implants

RSA and Registries: The Quest for Phased Introduction of New Implants

Although the overall survival of knee and hip prostheses at ten years averages 90%, recent problems with several hip and knee prostheses have illustrated that the orthopaedic community, industry, and regulators can still further improve patient safety. Given the early predictive properties of roentgen stereophotogrammetric analysis (RSA) and the meticulous follow-up of national joint registries, these two methods are ideal tools for such a phased clinical introduction. In this paper, we elaborate on the predictive power of RSA within a two-year follow-up after arthroplasty and its relationship to national joint registries. The association between RSA prosthesis-migration data and registry data is evaluated. The five-year rate of revision of RSA-tested total knee replacements was compared with that of non-RSA-tested total knee replacements. Data were extracted from the published results of the national joint registries of Sweden, Australia, and New Zealand. There was a 22% to 35% reduction in the number of revisions of RSA-tested total knee replacements as compared with non-RSA-tested total knee replacements in the national joint registries. Assuming that the total cost of total knee arthroplasty is $37,000 in the United States, a 22% to 35% reduction in the number of revisions (currently close to 55,000 annually) could lead to an estimated annual savings of over $400 million to the health-care system. The phased clinical introduction of new prostheses with two-year RSA results as a qualitative tool could lead to better patient care and could reduce the costs associated with revision total knee arthroplasty. Follow-up in registries is necessary to substantiate these results and to improve post-market surveillance.

Extent of corpectomy determines primary stability following isolated anterior reconstruction in a thoracolumbar fracture model

Background Based on the development of minimal-invasive techniques and introduction of new implants enabling secure reconstruction an increasing number of patients are treated by isolated anterior column surgery. Most biomechanical studies dealing with thoracolumbar fracture models use worst-case scenarios of complete corpectomies to simulate vertebral body defects neglecting the influence of remaining cortical bone in partial corpus instability. Using a standardized partial and total corpectomy model we investigated the effect of the extent of corpectomy on stiffness in an anterior reconstruction model. Methods Twelve human thoracolumbar specimens (Th11-L3) were loaded in a spine simulator with pure moments in the three motion planes. Following intact testing partial corp- and discectomy and later complete corpectomy of L1 were performed. Defects were instrumented by vertebral body replacements and additional anterior plating systems bridging the defect from Th12 to L2. Intersegmental rotations were measured between Th12 and L2. Findings Significantly ( P < 0.05) increased range of motion was found in reconstructions of total compared to partial corpectomy. Total corpectomy reconstructions showed solely in lateral bending a significant reduction of range of motion compared to the intact state, while in axial rotation and flexion/extension it was significantly increased. Partial corpectomy reconstructions resulted in significantly reduced range of motion for lateral bending and flexion/extension compared to the intact specimen. Interpretation Isolated anterior reconstructions of the thoracolumbar spine revealed sufficient stiffness in the partial vertebral corpus defect. In contrast, total corpectomy did not show an adequate stiffness. Especially in regard to rotational stiffness additional posterior fixation has to be recommended.

Future Directions in Breast Implant Surgery

Breast implant surgery will remain a major component of the practice of plastic surgery. The future may hold promise for the introduction of new implants for the augmentation of the breast and for reconstruction. The constant demand and pressure placed on the manufacturers to keep developing new fillers are proof that satisfaction with saline implants is lacking. Today, however, the saline implant may be believed to be the safest breast implant available for clinical application. The demand necessitates that implants be used for enhancement of a woman's self image and for reconstruction. The smooth-surface implants are considered more popular and safer for patients, perhaps because it has been well documented that the shell may have been the cause of the problem. However, the constancy in holding on using and reapplying the same principles of a faulty shell may not be as scientific an endeavor as we have done in the past, and to keep placing different fillers in the faulty shell. Perhaps the lamination process used in manufacturing, the air in the shell, or wear and tear produces mechanical weakening of the shell that eventually will lead to loss of integrity of the silicone-shell breast implant. The global community is looking to plastic surgeons for a solution. The applications and the demand for breast implants are global in nature. Meanwhile, as clinicians are waiting for a new implantable breast device, they will continue to use what is available and advise patients that the implantation of a breast prosthesis is not a life-long endeavor. There is a need, however, for the implants to be maintained by the process of exchange every 8 to 10 years. Breast reaugmentation is to be performed as a standard because plastic surgeons will be waiting for further clarifications from the regulators or the scientific community. The goal is to produce a good outcome and maintain safety for the patients with a high standard of care.

A complementary thoracic implant for the surgical correction of the scoliotic curve. A preliminary report

The results of the surgical correction of scoliosis through posterior approach have significantly improved by the introduction of new implants during the past decades. Even with these improvements the available implants only allow limited correction especially regarding axial rotation, and also their application is rather complicated. We developed a new implant which simultaneously grasps and exerts forces on both transverse processes of the vertebrae, to achieve a more efficient and safer correction with a simple surgical technique. In our paper we report on the concept of the new implant, its most important features, its mechanical tests, cadaver experimentations, and biomechanical assessments.