Durable Fixation Research Articles

Management of Bone Loss in Revision Total Knee Arthroplasty: An International Consensus Symposium.

The evaluation, classification, and treatment of significant bone loss after total knee arthroplasty (TKA) continue to be a complex and debated topic in revision TKA (rTKA). Despite the introduction of new evidence and innovative technologies aimed at addressing the approach and care of severe bone loss in rTKA, there is no single document that systematically incorporates these newer surgical approaches. Therefore, a comprehensive review of the treatment of severe bone loss in rTKA is necessary. The Stavros Niarchos Foundation Complex Joint Reconstruction Center Hospital for Special Surgery, dedicated to clinical care and research primarily in revision hip and knee replacement, convened a Management of Bone Loss in Revision TKA symposium on June 24, 2022. At this meeting, the 42 international invited experts were divided into groups; each group was assigned to discuss questions related to 1 of the 4 topics: (1) assessing preoperative workup and imaging, anticipated bone loss, classification system, and implant surveillance; (2) achieving durable fixation in the setting of significant bone loss in revision TKA; (3) managing patellar bone loss and the extensor mechanism in cases of severe bone loss; and (4) considering the use of complex modular replacement systems: hinges, distal femoral, and proximal tibial replacements. Each group came to consensus, when possible, based on an extensive literature review and interactive discussion on their group topic. This document reviews each these 4 areas, the consensus of each group, and directions for future research.

Pertrochanteric Nonunion: When and Why to Consider a Medullary Implant.

Pertrochanteric nonunion management is a technically challenging problem. When repair is undertaken rather than conversion arthroplasty, successful treatment revolves around accurate deformity correction, preservation of vascularity, and stable durable fixation. The decision to use an extramedullary or intramedullary implant should be influenced by nonunion-specific characteristics and patient-related conditions. Failure to understand these nuances when selecting an implant strategy often results in treatment failure. The primary purpose of this article was to discuss these variables and delineate when an intramedullary implant should be considered for treatment of a pertrochanteric nonunion. The secondary purpose was to describe the author's preferred surgical technique for implant-driven deformity correction and compression when choosing an intramedullary nail.

The Triple-Double Technique of Arthroscopic Hill-Sachs Remplissage

Surgeons are increasingly treating Hill-Sachs lesions arthroscopically by suturing the posterior rotator cuff and capsule into the defect, a procedure known as “remplissage.” A number of remplissage techniques have been described in the literature, and these often vary by the number and location of suture anchors. The “triple-double” technique of arthroscopic Hill-Sachs remplissage can be used for larger lesions. This technique utilizes a three-anchor configuration secured by interconnected double-mattress sutures to provide durable fixation through a large contact area between the capsulotenodesis tissue and the prepared bone bed to theoretically optimize healing.

Three-dimensional design custom-made uncemented stem for revision of cemented distal femoral endoprosthesis due to aseptic loosening

BackgroundRevision of cemented distal femoral replacement (DFR) due to aseptic loosening is challenging because of the resultant femoral bone loss. This paper aims to examine the outcomes of three-dimensional (3D) design custom-made uncemented stems for revision.MethodsBetween January 2014 and December 2020, 17 patients received 3D design uncemented stems for revision of loosed cemented DFR. The femoral bone loss was classified into four Grades, and four types of uncemented stems were designed correspondingly. The revision stems were custom-made for each patient by measuring the diameter of the medullary cavity and the anterior curvature of the femur.ResultsThe patient counts with their corresponding Grades of femoral bone loss were as follows: Grade I, 8 patients; Grade II, 5 patients; Grade III, 3 patients; and Grade IV, 1 patient. During the mean follow-up of 80 months, no revision failure was detected. The postoperative radiographic showed that the stem matched the femoral anterior curvature well. The femoral bone defect was completely filled by the 3D design stem in 10 of the 17 cases postoperatively. In the remaining cases, the persistent peri-stem defect was filled or partially restored during the follow-up.Conclusion3D design custom-made uncemented stem created precise, stable, and durable fixation and provided satisfactory clinical outcomes, which seems to be a viable method for cemented DFR revision.

TIBIAL METAPHYSEAL CONES COMBINED WITH SHORT STEMS PERFORM AS WELL AS LONG STEMS IN REVISION TOTAL KNEE ARTHROPLASTY

Little information exists regarding optimal tibial stem usage in revision total knee arthroplasty (rTKA) utilising a tibial trabecular metal (TM) cone. The purpose of this study was to compare 1) functional outcomes, 2) radiographic outcomes, and 3) implant survivorship in rTKA utilising TM cones combined with either short stems (SS) or long stems (LS) at minimum two-years clinical follow-up.In this retrospective, multi-centre study, patients undergoing TM cone utilising rTKA between 2008 and 2019 were included. Patients were divided into: SS group (no diaphyseal engagement), and LS group (diaphyseal engagement). All relevant clinical charts and post-operative radiographs were examined. Oxford Knee Score (OKS) and EuroQol-5D (EQ-5D-5L) data were collected at most recent follow-up.In total, 44 patients were included: 18 in the SS group and 26 in the LS group. The mean time of follow-up was 4.0 years. Failure free survival was 94.5% for the SS group and 92.3% for the LS group. All failures were for prosthetic joint infections managed with debridement, antibiotics, and implant retention. At most recent follow-up, 3 patients demonstrated radiographic signs of lucency (1 SS 2 LS, p = 1) and the mean OKS were 37 ± 4 and 36 ± 6 (p = 0.73) in the SS and LS groups, respectively.Tibial SS combined with TM cones performed as well as LS in rTKA at minimum two-years follow-up. A tibial SS in combination with a TM cone is a reliable technique to achieve stable and durable fixation in rTKA.

Bony glenoid reconstruction in revision arthroplasty

Glenoid pathologies are one of the main indications for shoulder arthroplasty revisions. In most cases, the glenoid bone defect is associated with insufficiency of the rotator cuff, so that only reverse total shoulder arthroplasty can be considered as arevision implant. For stable permanent fixation of the reverse glenoid component, to avoid inferior glenoid notching, and to achieve optimal function, physiological restoration of three-dimensional glenoid anatomy is necessary. In order to approach the individual glenoid pathologies in adifferentiated and optimal manner, it is important to classify the defects. Abasic distinction must be made between centric contained and eccentric uncontained defects. Combinations often occur. It is also important to consider the severity, depth, and three-dimensional orientation of the defect. Therefore, aCT analysis of the glenoid is essential preoperatively. The data obtained should serve as the basis for computer-assisted planning to determine the optimal position of the glenoid baseplate and the type and shape of the bone graft for the reconstruction. For patients with good bone quality, we recommend defect reconstruction with autologous iliac crest. The type of graft configuration and fixation and the decision between aone- and two-stage procedure depend on the type and severity of the defect. With technically correct reconstruction and proper prosthesis implantation, sufficient integration of the bone graft and durable fixation of the glenoid component can be expected with satisfactory clinical results. After bony reconstruction of the defects, repeated treatment with areverse arthroplasty is possible in the long term in the event of renewed glenoid problems.

The exeter cemented stem provides outstanding long-term fixation and bone load at 15years follow-up: A systematic review and meta-analysis.

Since its introduction in 1988, the double-tapered polished Exeter cemented stem has been widely adopted in primary total hip arthroplasty (THA). Despite the results coming from the arthroplasty registries have proven great survivorship, the aim of this study was to dig deeper and describe the modes of failure of the Exeter stem at 15years follow-up while reporting the clinical and radiographic outcomes. A search of PubMed, MEDLINE, and Embase was performed using the Preferred Reporting Items for Systematic Review and Meta-Analyses since inception of database to January 2022. A meta-analysis was performed on stem's failure rates and clinical outcomes using random effects models. Publication bias was assessed with funnel plots. Overall, ten studies met the inclusion criteria with 2167 hips at mean 14.8 ± 4.1years follow-up. The meta-effect estimate for revision rate for stem-related reasons was 3.8% (CI 95% 2.1-5.6, p < 0.01). The meta-effect for revision rate for stem aseptic loosening (AL) was 0.22% (CI 95% 0-0.4, p = 0.048) and for periprosthetic fracture was 0.6% (CI95% 0.3-0.9, p < 0.001). The meta effect estimate for Oxford Hip Score (OHS) at final follow-up was 32.4 (moderate; CI 95% 23.2-41.6, p <0.001) with and heterogeneity among the studies of I2 0%. Radiolucent lines were reported in 5.5% of cases, with 1.0% of cases (21 hips) reported to be progressive. Current evidence suggests that the Exeter cemented stem not only has proven long-term outstanding reliability with a revision rate of 3.8%, but also incredibly low revision rates for AL (0.22%) and periprosthetic fracture (0.6%). It is suitable for a variety of indications, and the consistent radiological appearances indicate durable fixation and load transmission while being associated with a remarkably low stem-related complication rate.

Finite element analysis of screw fixation durability under multiple boundary and loading conditions for a custom pelvic implant.

Despite showing promising functional outcomes for pelvic reconstruction after sarcoma resection, custom-made pelvic implants continue to exhibit high complication rates due to fixation failures. Patient-specific finite element models have been utilized by researchers to evaluate implant durability. However, the effect of assumed boundary and loading conditions on failure analysis results of fixation screws remains unknown. In this study, the postoperative stress distributions in the fixation screws of a state-of-the-art custom-made pelvic implant were simulated, and the risk of failure was estimated under various combinations of two bone-implant interaction models (tied vs. frictional contact) and four load cases from level-ground walking and stair activities. The study found that the average weighted peak von Mises stress could increase by 22-fold when the bone-implant interactions were modeled with a frictional contact model instead of a tied model, and the likelihood of fatigue and pullout failure for each screw could change dramatically when different combinations of boundary and loading conditions were used. The inclusion of additional boundary and loading conditions led to a more reliable analysis of fixation durability. These findings demonstrated the importance of simulating multiple boundary conditions and load cases for comprehensive implant design evaluation using finite element analysis.

Tibial metaphyseal cones combined with short stems perform as well as long stems in revision total knee arthroplasty

BackgroundsThere is uncertainty around optimal tibial stem length in revision total knee arthroplasty (rTKA) utilizing a tibial trabecular metal (TM) cone. The purpose of this study was to compare: (1) functional outcomes, (2) radiographic outcomes and (3) implant survivorship in rTKA utilizing TM cones combined with either short stems (SS) or long stems (LS) at minimum 2 years follow‐up.MethodsIn this retrospective, multi‐centre study, patients undergoing rTKA utilizing a TM cone between 2008 and 2019 were included. Patients were divided into: SS group (no diaphyseal engagement), and LS group (diaphyseal engagement). All relevant clinical charts and post‐operative radiographs were examined. Oxford Knee Score (OKS) and EuroQol‐5D (EQ‐5D‐5L) data were collected at most recent follow‐up.ResultsIn total, 44 patients were included: 18 in the SS group and 26 in the LS group. The mean time of follow‐up was 4.0 years. Failure free survival was 94.4% for the SS group and 92.3% for the LS group. All failures were for prosthetic joint infections managed with debridement, antibiotics, and implant retention. At most recent follow‐up, 3 patients demonstrated radiographic signs of lucency (1 SS 2 LS, P = 1) and the mean OKS were 37 ± 4 and 36 ± 6 (P = 0.73) in the SS and LS groups, respectively.ConclusionTibial SS combined with TM cones performed as well as LS in rTKA at minimum 2 years follow‐up. A tibial SS in combination with a TM cone is a reliable technique to achieve stable and durable fixation in rTKA.

Cemented Versus Cementless Total Knee Arthroplasty in Obese Patients With Body Mass Index ≥35 kg/m2: A Contemporary Analysis of 812 Patients.

Cemented total knee arthroplasty (TKA) has been shown to have higher failure rates in obese patients, and cementless TKA may provide more durable fixation. This study compared outcomes and survivorship of obese patients undergoing cemented and cementless TKA of the same modern design. We identified a consecutive series of 406 primary cementless TKA performed in obese patients with body mass index (BMI) ≥35 kg/m2 in 2013-2018. Each case was matched 1:1 with 406 cemented TKA based on age, sex, BMI, bearing surface, and year of surgery. Knee Injury and Osteoarthritis Outcome Score for Joint Replacement and Short Form-12 were collected preoperatively, at 6 months and 2 years. Implant survivorship was recorded at mean 4.0 years (range 2.0-7.8). There was no difference in mean BMI between the cemented (38.6 ± 3.4 kg/m2; range, 35-60) and cementless cohorts (38.7 ± 3.3 kg/m2; range, 35-54; P= .706). Both groups had similar final postoperative scores and improvement in scores at 2 years. Furthermore, a similar percentage met the minimal clinically important difference (Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, 70.0% vs 71.2%, P= .700; Short Form-12 Physical, 74.1% vs 70.4%, P= .240). Both groups demonstrated high 7-year survivorship free from aseptic revision (99.0% vs 99.5%, P= .665). Obese patients with BMI ≥35 kg/m2 undergoing cementless and cemented TKA of the same modern design had similar outcomes and survivorship at early to mid-term follow-up. Continued surveillance of this high-risk population is necessary.

Tibial metaphyseal sleeves in primary total knee arthroplasty following high tibial osteotomy and tibial plateau fracture; preliminary mid-term survival and outcome

BackgroundPrevious high tibial osteotomy (HTO), and tibial plateau fractures (TPF) may cause problems in subsequent total knee arthroplasty (TKA) due to altered metaphyseal bone structure. Higher rates of loosening of the tibial component have been described.In post-HTO and TPF cases, a more durable fixation could be achieved by tibial sleeves. This study investigates the preliminary short-to-midterm clinical and radiographic results in a cohort of these cases. MethodsA cohort of 28 patients was selected, 11 following HTO, and 17 following TPF. Standard clinical and radiologic follow-up was performed at 6 weeks, and one and two years. Revision with removal of primary prosthesis for any reason was the primary outcome. Patient reported pre- and postoperative pain, satisfaction and general health scores were collected at one and two years. Postoperative radiographs were analyzed for radiolucent lines. ResultsThere were no cases of aseptic loosening. Survival for all reasons was 96.4% (CI 77.2%–99.5%). One progressive radiolucent line was seen. Numerical rating scale (NRS) for pain with and without weightbearing at 2-year follow-up improved from 8 to 3 and from 5 to 2 points respectively. Overall general health scores improved with a median of 70 at ≥ 2 years, compared to 63 pre-operatively. ConclusionWith no revision for aseptic loosening the use of tibial sleeves in primary TKA seems a safe and reliable method for fixation of the tibial component in metaphyseal bone with altered bone structure at short and mid-term follow-up.Level of evidence: Level IV, cohort study.

How surface coatings on titanium implants affect keratinized tissue: A systematic review.

Apart from osseointegration, the stability and long‐term survival of percutaneous titanium implants is also strongly dependent on a qualitative soft‐tissue integration in the transcutaneous region. A firm connective tissue seal is needed to minimize soft‐tissue dehiscence and epithelial downgrowth. It is well‐known that the implant surface plays a key role in controlling the biological response of the surrounding keratinized tissue and several coating systems have been suggested to enhance the soft‐tissue cell interactions. Although some promising results have been obtained in vitro, their clinical significance can be debated. Therefore, the purpose of this systematic review is to gain more insight into the effect of such coatings on the interface formed with keratinized soft‐tissue in vivo. A comprehensive search was undertaken in March 2021. Relevant electronic databases were consulted to identify appropriate studies using a set of search strings. In total, 12 out of 4971 publications were included in this review. The reported coating systems were assigned to several subgroups according to their characteristics: metallic, ceramic and composite. Notwithstanding the differences in study characteristics (animal model, implantation period, reported outcomes), it was noticed that several coatings improve the soft‐tissue integration as compared to pristine titanium. Porous titanium coatings having only limited pore sizes (<250 μm) do not support dermal fibroblast tissue attachment. Yet, larger pores (>700 μm) allow extensive vascularized soft‐tissue infiltration, thereby supporting cell attachment. Nanostructured ceramic coatings are found to reduce the inflammatory response in favor of the formation of cell adhesive structures, that is, hemidesmosomes. Biomolecule coatings seem of particular interest to stimulate the soft‐tissue behavior provided that a durable fixation to the implant surface can be ensured. In this respect, fibroblast growth factor‐2 entrapped in a biomimetic apatite coating instigates a close to natural soft‐tissue attachment with epidermal collagen fibers attaching almost perpendicular to the implant surface. However, several studies had limitations with respect to coating characterization and detailed soft‐tissue analysis, small sample size and short implantation periods. To date, robust and long‐term in vivo studies are still lacking. Further investigation is required before a clear consensus on the optimal coating system allowing enhancing the soft‐tissue seal around percutaneous titanium implants can be reached.

Тотальное эндопротезирование тазобедренного сустава в течение последних 25 лет

Тотальное эндопротезирование тазобедренного сустава (ТЭТС) является одной из наиболее клинически эффективных и экономически целесообразных ортопедических процедур в течение последних пяти десятилетий. Прочность фиксации цементной бедренной ножки остается стандартом, с которым сравнивают все современные методы фиксации. Выживание ножек составило 82 % при 20-летнем периоде и 81 % при 30-летнем. При этом выживание ацетабулярных чашек составило 71 и 52 % соответственно. В североамериканском регистре больных с протезированием тазобедренного и коленного суставов использование цементных чашек уменьшилось с 12 % в 1995 году до 7,8 % в 2001 году. Клинические данные не указывают на стойкие клинические преимущества методов малоинвазивной хирургии (Minimally Invasive Surgery, MIS) по сравнению с традиционными хирургическими доступами. Нередко встречаются серьезные осложнения, связанные с использованием данного метода. В последнее десятилетие наблюдается резкое снижение частоты клинического использования методов MIS при ТЭТС. В период с 1993 года во всем мире наблюдалось последовательное увеличение объемов поверхностного эндопротезирования тазобедренного сустава. До 2008 года поверхностное эндопротезирование тазобедренного сустава составляло 6–9 % от всех ТЭТС. Несмотря на заинтересованность больных поверхностным эндопротезированием, боязнь осложнений и выживание имплантатов в длительной перспективе, а также неизвестные последствия влияния ионов металлов и связанные с ними неблагоприятные тканевые реакции привели к сокращению количества поверхностного эндопротезирования тазобедренного сустава в большинстве стран. Инновации в области обработки полиэтилена привели к улучшению его износостойких характеристик. Идеальный полиэтиленовый материал должен иметь высокую плотность поперечных связей (крепкая межмолекулярная связь) и низкий потенциал окисления. Это достигается за счет увеличения дозы облучения, которая подается на полиэтилен (до 10 Мрад), что увеличивает количество поперечных связей. Чтобы снизить окислительный потенциал, компоненты облучают в бескислородной среде с барьерной упаковкой. Существует ограниченное количество доказательств сравнительной эффективности разных пар трения тазобедренных суставов. Рандомизированные клинические исследования демонстрируют похожие коротко- и среднесрочные периоды выживания среди керамо-керамической пары трения, керамики с кросс-линкованным полиэтиленом и металла с кросс-линкованным полиэтиленом у больных моложе 65 лет. Керамические головки приобретают все большую популярность по сравнению с металлическими головками. Огромные различия до сих пор существуют среди стран по частоте использования цементной и бесцементной фиксации. В 2013 году в некоторых странах использование цементных ножек было меньше 4 %, в других странах оно составляло более 68 % в том же году. Во всем мире сегодня существует тенденция к увеличению количества бесцементной фиксации. Общенациональная база данных пациентов США демонстрирует причины проведения ревизионного ТЭТС: среди 51 345 повторных ТЭТС вывихи составляли 22,5 %, асептическая нестабильность — 19,7 %, инфекция — 14,8 %. В 2030 году клиническая потребность в первичном ТЭТС увеличится на 174 %, до 572 000 случаев в год, по сравнению с 2002 годом, а спрос на ревизионное ТЭТС увеличится на 137 % до 2030 года.

Интрасклеральное ущемление узлов без вскрытия конъюнктивы и обнажения склеры при склеральной усиленной шовной фиксации интраокулярной линзы: собственная модификация

Purpose. Development of new technique for scleral reinforced suture fixation of intraocular lens (IOL) in the absence of capsule support with intrascleral capture of knots without conjunctival opening. Material and methods. Three patients with «IOL-capsular bag» complex dislocation into the vitreous cavity underwent scleral fixation of the IOL in the new modification. The IOL was placed into ciliary sulcus on two 9-00 double polypropylene sutures brought out transsclerally without conjunctival opening. Both sutures were passed intrasclerally for 3.0 mm, sticking each of needles into the sclera at the points of sutures exit from conjunctiva, and brought out through conjunctiva. Threads were cut, leaving 2.0 mm free ends, and knots (2-1-1) were tied with the tension necessary to capture them in the scleral canals. At the points of exit of threads' ends from the conjunctiva, additional needles with looped double threads were sticked again, passed intrasclerally for 3.0 mm and were brought out through conjunctiva; ends of the threads fixing the IOL were captured in loops and dipped in the scleral canals. Results. During the follow-up, position of the IOL was correct, sites of neddles' sticks into the conjunctiva were epithelized, and no tendency to erosion of intrascleral threads was observed. Conclusions. New modification of scleral fixation of IOLs is technically simple, does not require conjunctival opening. It involves the use of double suture, which increases the durability of fixation. Technique can be used for fixation of any IOL model, as well as artificial irido-lens diaphragm, intracapsular ring or intracapsular segment. Key words: scleral fixation of intraocular lens.

Basic principles of odontopreparation for non-removable orthopedic structures (literature review)

Introduction. The actual problem of dentists-orthopedists at the present time is a violation of the odontopreparation protocol and, as a result, poor-quality fixation of various non-removable orthopedic structures. For a strong and reliable fixation of non-removable orthopedic structures, special requirements must be imposed on them in terms of the shape and surface of the support of the processed tooth. These requirements include: parallelism of the walls of the prepared tooth (must be cylindrical); parallelism of the vertical walls of the stumps of the teeth, high-quality gingival ledge [1, 2]. Qualitatively prepared teeth for orthopedic structures, observance of parallelism of the walls create optimal conditions for stable fixation of orthopedic structures. Correctly executed gingival ledge promotes durable fixation of the crown and eliminates the likelihood of infection under it. After analyzing a large volume of domestic and foreign literature, it can be concluded that the creation of various methods of odontopreparation with the task of creating the most favorable supragingival part of the tooth for further fixation of the orthopedic structure is a significant problem in modern dentistry. The creation and clinical testing of DNT (dental navigation technologies) allows for accurate quality control of the performed odontopreparation. The purpose of this article was to analyze the existing methods of odontopreparation and identify the most effective ones among them.

Implant survival and functional results of endoprosthetic reconstruction for proximal femoral metastases with pathological fractures.

This study aimed to evaluate the patient and implant survival, clinical and functional outcomes, and the rate of complications resulting in reconstruction failure following endoprosthetic reconstruction (EPR) of extensive proximal femoral metastases associated with actual or impending pathological fractures. A total of 111 patients with actual or impending pathological fractures due to metastatic disease of the proximal femur were treated with EPR between 2003 and 2018. Staged surgery, bilateral EPR, was performed in 3 cases. The patients comprised 51 females and 60 males with a mean age of 52.1 ± 12.3 years. The patient and implant survival were recorded. Clinical and functional outcomes were assessed by using the visual analogue scale (VAS), Musculoskeletal Tumour Society (MSTS) functional scoring, and Karnofsky Performance Scale (KPS). The different types of abductor mechanism repair were evaluated by functional tests and existence of Trendelenburg gait at postoperative follow-ups. The complications resulting in reconstruction failure were investigated. The mean follow-up was 23.1 ± 17.9 months. The overall survival of patients after EPR was 89% at 6 months, 72% at 1 year and 10% at 5 years. The estimated 1- and 5-year overall implant survival was 100% and 97.3% (95% CI, 0.95-0.98), respectively, as the endpoint was defined as complete removal of the prosthesis. Median VAS score before endoprosthetic replacement was 8 and after 3 months 4. Before surgery, the median MSTS score was 40 (30-56.6%) and the median KPS score was 40 (30-50). Postoperative third month, the median MSTS score was 56.6 (53.3-86.6%) and the median KPS score was 60 (40-70). Functional scores were superior in trochanter major split osteotomized group compared to trochanter major removed group. Trendelenburg gait was seen in 20 (17.5%) patients postoperatively. There were 10 (8.7%) complications resulting in reconstruction failure. Endoprosthetic replacement can provide a durable fixation with high implant survival rate and good clinical and functional results in extensive proximal femoral metastases associated with a pathological fracture.

Constrained liners revisited: favourable mid-term results in patients with high-risk of dislocation: technical considerations for the optimal outcome.

The outcomes of constrained liners (CLs) in total hip arthroplasty (THA) remain inconclusive. We evaluated the mid-term performance of CLs in a consecutive series of high-risk dislocation patients undergoing primary or revision THA performed by a single surgeon. The survival, dislocation rate, complications, and functional patients' scores were assessed. Surgical tips to enhance outcomes were reviewed. 45 patients who received the Trident Tripolar CL between 2010 to 2019 were retrospectively evaluated from Arthroplasty Registry Thessaloniki. There were 17 primary and 28 revision THAs. The primary indications for using CL were severe abductor insufficiency or comorbidities, increasing the dislocation risk in primary, and recurrent dislocation or abductor insufficiency in revision THAs. The mean patient's age was 68.5 (±14.5) years, and the mean follow-up 3.81 (±1.66) years. There were 2 dislocations and 1 deep infection in the revision group. For any reason, the cumulative 6-year survival rate was 93.3%, 100% for primary, and 89.3% for revision THAs. The mean overall CL survival was 76.3 months for any reason (95% CI, 68.1-84.5) and 80.5 months for dislocation (95% CI, 75.8-85.2). The mean postoperative functional scores were significantly improved (p < 0.001) at the latest follow-up. CLs can provide hip stability and durable fixation in selected low-demand patients with high-risk for dislocation after primary and revision THA at mid-term follow-up. Careful patient selection and the refined surgical technique aiming at the neutral liner position and considering the high CLs' offset relative to stem-neck impingement are necessary to maximise outcomes.

CORR Insights®: Compliant Compression Reconstruction of the Proximal Femur Is Durable Despite Minimal Bone Formation in the Compression Segment.

CORR Insights®: Compliant Compression Reconstruction of the Proximal Femur Is Durable Despite Minimal Bone Formation in the Compression Segment.

Early Survivorship of Newly Designed Highly Porous Metaphyseal Tibial Cones in Revision Total Knee Arthroplasty.

BackgroundMetaphyseal cones provide durable fixation in revision total knee arthroplasty (TKA). However, there is a paucity of data on the outcomes of a new porous cone design. As such, the goal of this study was to analyze the early survivorship in patients undergoing revision TKA with this cone.MethodsWe retrospectively reviewed 163 revision TKAs with a newly designed porous tibial cone from 2016 to 2018. Mean age was 67 years, and mean body mass index was 33 kg/m2. Minimum follow-up duration was 2 years. Most patients were revised for aseptic loosening (46%), 2-stage periprosthetic joint infection (PJI) reimplantation (28%), or instability (15%). Most were varus-valgus constrained (65%) or hinged (32%) constructs. The majority had hybrid tibial stem fixation (74%). A multivariate Cox regression analysis was used to identify risk factors for reoperation.ResultsSurvivorship free from re-revision for aseptic loosening, any nonmodular revision, and any reoperation was 100%, 96%, and 86% at 2 years, respectively. No patients were revised for aseptic loosening. Six (4%) tibial cones were removed for PJI, one of which was loose. There were 23 reoperations (14%), most commonly for PJI (10%). Multivariate analysis identified PJI reimplantation (hazard ratios [HR] = 4.2, P = .002), males (HR = 2.9, P = .02), and hinged constructs (HR = 2.7, P = .02) as significant risk factors for reoperation.ConclusionsIn a complex revision TKA cohort with a new highly porous tibial cone, in which most patients received hybrid stem fixation and nonlinked and linked constraint, there was 100% survival free from re-revision for aseptic loosening at 2 years. Longer term follow-up is required.

Megaprosthesis as a treatment modality for persistent distal femoral nonunion in middle aged adults

Introduction:Managing distal femur non-union can be a struggle for any orthopedician as it brings along many perplexities which may not lead to satisfactory patient outcome. The target in these cases should be to reduce the morbidity and allow early rehabilitation of the patient and to accomplish this, megaprostheses can be a feasible option. The orthodox use of megaprostheses is in the musculo-skeletal oncologic surgeries but its use can be extended to traumatic etiologies. These can be offered as a single stage definite procedure in patients who have already undergone several previous surgeries. Here we report a series of four cases of persistent non-union of distal femur treated with megaprostheses and recommend this modality for achieving the desired goal but the indication should be meticulously selected.Hypotheses:Megaprosthesis as a definitive treatment option in persistent distal femur non-union and prevention of repeated surgical intervention.Methods:Four cases of persistent distal femur nonunion with failed osteosynthesis were selected who were initially treated with a distal femur locking plate. Results were assessed in terms of range of motion, limb length discrepancy, knee society score and osteointegration of the components.Results:The mean age of the patients at the time of DFEPR was 49 years (42-55).The mean follow up of patients was for approximately 2 years, with the longest follow up being 3.5 years for the first operated case of the series. The range of motion was from full extension to about 105 degrees of flexion with two patients having an extension lag of 10 degrees. Patients were ambulatory without support. Postoperatively, the mean knee society score was 83 (78–88) at last follow-up as compared to 29 (21-36) in the pre-operative period. No case of infection or loosening was reported. There was 1 cm of shortening in one patient in the operated limb which was compensated by giving shoe raise. Good osseointegration of the megaprosthesis was revealed on both anteroposterior and lateral radiographs.Conclusion:Although there are very limited studies on the use of megaprosthesis for traumatic cases, it can be considered as an alternative when we are left with only arthrodesis or amputation as the final option. Despite the operative challenges, there is marked improvement in pain and functional capacity as experienced by these severely limited patients, which are the hallmarks of a successful salvage. The use of distal femur mega-prosthesis is a novel acumen in cases, where bone stock at the fracture site at distal end of femur is so severely compromised that traditional revision osteosynthesis would not provide stable and durable fixation. The indications for this surgery must be rigorously selected and should only complement osteosynthesis procedures, which remain the reference treatment option.