Prosthetic Knee Joint Research Articles

Modular component exchange has no advantage in Debridement, Antibiotics and Implant Retention (DAIR) for early onset hip and knee prosthetic joint infection.

Debridement, Antibiotics and Implant Retention (DAIR) has been the mainstay of treatment for early onset periprosthetic joint infection in spite of variable results. Modular component exchange is a widely recommended strategy to improve success rates with DAIR though very strong evidence to support its practice is still lacking. Eighty six patients underwent DAIR for early onset PJI following primary hip and knee arthroplasty were divided into two groups for this retrospective review. 45 patients (group 1) underwent DAIR with modular component exchange and 41 patients without exchange (group 2). We compared success rates based on infection eradication (primary outcome variable) and need for revision surgical procedures between these two groups. We also assessed differences in primary outcome based on type of arthroplasty, timing of DAIR and addition of local antibiotics. The overall success rate after DAIR was 71%. The outcome was similar in both groups (69% vs 74%, P = 0.66). The need for revision surgical procedures was 27% which was similar in both groups (P = 0.98) with 23% needing revision of prosthetic components. Type of arthroplasty (hip or knee) and addition of local antibiotics had no bearing on infection eradication after DAIR with or without modular component exchange. DAIR with in 45days of primary arthroplasty had significantly higher success rate compared to DAIR after 45days in both groups. We observed that modular component exchange did not improve infection eradication after DAIR for early onset PJI following hip and knee arthroplasty. Reasonable success rates can be expected after DAIR especially if the patient develops early clinical signs and the procedure is carried out as early as possible.

Kinematic and kinetic parameters of prosthetic knee joints during walking – Comparison of gait analysis results and internal sensor data

Kinematic and kinetic parameters of prosthetic knee joints during walking – Comparison of gait analysis results and internal sensor data

Prevalence and risk factors for haematogenous periprosthetic joint infection during Staphylococcus aureus bacteraemia

Background Staphylococcus aureus bacteraemia (SAB) may lead to periprosthetic joint infections (PJI) via haematogenous spread of bacteria to the joint. Due to the risk of PJI, patients with SAB and prosthetic joint are recommended prolonged antibiotic treatment. The aim of the study was to assess the risk of PJI during SAB, and to evaluate if short treatment duration affects outcomes in patients with uncomplicated SAB and prosthetic joints without clinical signs of PJI. Methods Patients with growth of S. aureus in blood cultures were cross-referenced against the Swedish Arthroplasty register to identify patients with prosthetic hip or knee joints at the time of SAB. Medical records were reviewed to identify PJI at the time of SAB and during a 6-month follow-up period. Results Out of 400 patients with SAB and a prosthetic joint, 281 met all eligibility criteria and were included in the study. Of the included participants, 35 (12%) had a haematogenous PJI. Younger age and presence of multiple prosthetic joints were associated with an increased risk of PJI. Of the 247 patients without signs of PJI at the initial SAB episode, 118 patients (48%) had an uncomplicated infection and received short total antibiotic treatment (median 15 days, IQR 13-17). The risk of PJI during the follow-up period was low (<1%) and similar in the uncomplicated group compared to patients with complicated SAB that received longer antibiotic treatment (median 29 days, IQR 15-70). Conclusion The prevalence of haematogenous PJI was lower than previously reported. Our data do not support prolonged antibiotic treatment in patients with SAB and prosthetic joints without clinical signs of PJI.

Paediatric Prosthetic Knee Design: The Technical Requirements of a Swing Phase Control Mechanism are Correlated with Parameters of Childhood Growth.

There is a lack of innovation in affordable prosthetic knee joints for children. One significant reason is the absence of technical requirements which consider the foundation of childhood: growth. This study aims to develop and use a modelling tool to determine the technical requirements throughout childhood growth for one prosthetic knee design feature, a swing phase control mechanism (SPCM). 3D gait data of 31 able-bodied children across a range of physical maturities were analyzed. For each participant 2 models were created from a validated paediatric able-bodied musculoskeletal model. The model was first linearly scaled, then a corresponding unilateral right knee-disarticulation amputation model produced by removing segments below the knee and replacing with prosthetic componentry. Long established low-cost prosthetic componentry and a novel polycentric knee were implemented. For each participant, inverse dynamics were conducted and the SPCM torque requirements defined. Prosthetic knee SPCM torque requirements were significantly less than the able-bodied knee to emulate able-bodied gait at free speed: 17.9% (± 10.2) and 66.3% (± 17.0) reduction in maximum extension and flexion torque, respectively. Maximum knee extension torque showed the strongest negative correlation with intact body mass (ρ = -0.6251) whereas flexion torque showed the strongest correlation with height (ρ = 0.6611). Corresponding linear regression fits produced RMSE of 1.91and 1.73 Nm, respectively. Results were also determined for slow and fast speeds. The torque requirements of an affordable paediatric prosthetic knee SPCM are defined and found to strongly correlate with parameters of childhood growth (body mass, height, and age). Current results recommend low-cost paediatric prosthetic SPCM designs can be tailored to accommodate growth. The creation of musculoskeletal models facilitate multiple future studies.

The Microbiology of Knee Prosthetic Joint Infection and its Influence on Persistent Infection.

Periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) is a severe complication causing a significant burden. The study aims were to establish the epidemiology of microorganisms in TKA PJI, the rate of persistent infection requiring further surgery, and the risk factors for this. Microbiological specimens between June 2002 and March 2017 at five regional hospital sites were identified with revision TKA procedures in the National Joint Replacement Registry. The time between procedures, type of revision strategy, and any subsequent further revision operations were collected. At minimum 2-year follow-up, 174 revision TKA were identified, with a mean patient age of 69 ± 11 years. A broad range of pathogens were identified. Fifty cases (29%) had persistent infection requiring at least one further operative procedure, 13 cases required 3 or more. Coagulase-negative Staphylococcus species (CNS) was seen most with failed surgery, polymicrobial infections also posing a significant risk factor. The best chance of a successful PJI surgical strategy was < 12 months from primary TKA, with the greatest risk between 3 and 5 years (p < 0.05). Younger age significantly increased the risk of further surgery (p < 0.05). Management varied; 103 (59%) debridement, antibiotic therapy and implant retention, with further surgery in 29%; 45 (17%) single-stage revision, with further surgery in 13%; and 26 (15%) two-stage revision, with further surgery in 12%. This study presents the most common causative pathogens for PJI in TKA, and the high rate of persistent infection after initial revision surgery. Risk factors for persistent infection and further revision surgery were polymicrobial and CNS infections, patients who presented between 3 and 5 years following primary TKA, and younger age. This study therefore raises important risk factors and areas for future research to reduce the burden of multiple operations after PJI.

Do High Doses of Multiple Antibiotics Loaded into Bone Cement Spacers Improve the Success Rate in Staphylococcal Periprosthetic Joint Infection When Rifampicin Cannot Be Employed?

Rifampicin is one of the mainstays in treating staphylococcal prosthetic joint infection (PJI). However, discontinuation due to intolerance, drug interactions, and adverse events is common. Two-stage revision surgery remains the gold standard, with the number of revision arthroplasties steadily increasing. This study aims to evaluate the effectiveness and safety of a novel two-stage revision protocol for staphylococcal prosthetic joint infection (PJI) utilizing bone cement spacers loaded with multiple high doses of antibiotics. Additionally, it seeks to analyze outcomes in patients ineligible for rifampicin treatment. A retrospective review of 43 cases of staphylococcal hip and knee prosthetic joint infections (PJIs) from 2012 to 2020 was conducted. In all instances, a commercial cement containing 1 g of gentamicin and 1 g of clindamycin, augmented with 4 g of vancomycin and 2 g of ceftazidime, was employed to cast a spacer manually after thorough surgical debridement. We report an eradication rate of 82%, with no significant differences observed (p = 0.673) between patients treated with (84%, n = 19) and without rifampicin (79%, n = 24). There were no disparities in positive culture rates (7%), spacer replacement (18%), or survival analysis (p = 0.514) after an average follow-up of 68 months (range 10-147) in the absence of systemic toxicity and surgical complications superimposable to those previously reported. In conclusion, two-stage revision with local high doses of ceftazidime, vancomycin, gentamicin, and clindamycin demonstrates high effectiveness in treating staphylococcal PJIs. Notably, systemic rifampicin does not influence the outcomes. This protocol, with multiple high doses of antibiotics loaded into the bone cement spacer, is presented as a viable and safe alternative for patients unsuitable for rifampicin treatment.

Lightweight design of prosthetic knee joint based on variable density method

Abstract The variable density method has emerged as an efficient approach for tackling the topology optimization challenge in continuous structures. In response to the increasing demand for lightweight prosthetic joints, a lightweight design was conducted, focusing on the front linkage rod - a crucial component of prosthetic joints. This study employed Altair Inspire software to optimize the motion-based topology of the front linkage rod. Additionally, the optimized model underwent geometric reconstruction and strength analysis. Subsequently, both the pre- and post-lightweight models were subjected to 3D printing to determine the weight reduction ratio. After confirming that the weight reduction ratio fell within the acceptable error range, a lightweight model was successfully achieved, exhibiting a remarkable weight reduction of 68.61% when compared to the initial model. This research introduces a fresh perspective on the lightweight design of prosthetic joints in motion, offering valuable insights for future endeavors in this field.

CAN WE PREDICT DAIR FAILURE IN PJI? EXTERNAL VALIDATION OF THE KLIC AND CRIME80 SCORES

IntroductionDebridement, antibiotics irrigation and implant retention (DAIR) is a common management strategy for hip and knee prosthetic joint infections (PJI). However, failure rates remain high, which has led to the development of predictive tools to help determine success. These tools include KLIC and CRIME80 for acute-postoperative (AP) and acute haematogenous (AH) PJI respectively. We investigated whether these tools were applicable to a Waikato cohort.MethodWe performed a retrospective cohort study that evaluated patients who underwent DAIR between January 2010 and June 2020 at Waikato Hospital. Pre-operative KLIC and CRIME80 scores were calculated and compared to success of operation. Failure was defined as: (i) need for further surgery, (ii) need for suppressive antibiotics, (iii) death due to the infection. Logistic regression models were used to calculate the area under the curve (AUC).Results117 eligible patients underwent DAIR, 53 in the AP cohort and 64 in the AH cohort. Failure rate at 2 years post-op was 43% in the AP cohort and 59% in the AH cohort. In the AP cohort a KLIC score of &lt;4 had a DAIR failure rate of 28.6%, while those who scored ³4 had a failure rate of 72.2% (p=0.002). In the AH cohort a CRIME80 score of &lt;3 had a DAIR failure rate of 48% while those who scored ³3 had a 100% failure rate (p&lt;0.001).DiscussionThis study represents the first external validation of the KLIC and CRIME80 scores for predicting DAIR failure in an Australasian population. The results indicate that both KLIC and CRIME80 scoring tools are valuable aids for the clinician seeking to determine the optimal management strategy in patients with AP or AH PJI.

A Meta-Analysis of Success Rates of One-Stage Versus Two-Stage Revisions in Knee Prosthetic Joint Infections.

Prosthetic joint infections (PJIs) pose significant challenges following total joint arthroplasties and cause profound complications. They are associated with significant morbidity and mortality. One-stage revision involves the removal of the infected implant and simultaneous re-implantation of a new prosthesis in a single surgical procedure. The two-stage approach is traditionally more common in the United States and follows a deliberate sequence: the infected implant is first removed, followed by a period of antibiotic therapy, and then a second surgery for implant reinsertion. While two-stage revisions were traditionally considered the gold standard, recent advancements have introduced one-stage revisions as a viable alternative. One-stage revision offers the advantage of being a single procedure, significantly reducing the patient's downtime without a functioning knee. Currently, there has not been a comprehensive exploration of the comparative outcomes between two-stage revisions and one-stage revisions. This systematic review and meta-analysis aimed to assess the outcomes of both one- and two-stage revisions for total knee arthroplasties (TKAs), by utilizing comparison studies as the foundation for analysis. Our search encompassed databases such as MEDLINE (Medical Literature Analysis and Retrieval System Online), Embase, and Cochrane to identify articles examining the comparative efficacy and outcomes of one- and two-stage revision procedures between January 2000 and June 2023. We employed keywords relevant to knee PJIs to identify comparative studies reporting on success rates, reinfection rates, microbiological findings, and other pertinent outcomes. Statistical analysis for this investigation was performed using Review Manager 5.4 (The Cochrane Collaboration, 2020) with a standard significance threshold set at a p-value less than .05. This meta-analysis incorporated six comparison articles and 802 patients. Two-stage revisions (547 patients) were associated with greater success rates (i.e., infection eradication) than one-stage revisions (255 patients) (p = .03). The studies did not suggest a difference in the microbiology of the infections. Two-stage revisions are associated with higher success rates than one-stage revisions in the treatment of knee PJIs. Future randomized controlled trials should evaluate the optimization of the management of these complications.

Exploration and demonstration of explainable machine learning models in prosthetic rehabilitation-based gait analysis.

Quantitative gait analysis is important for understanding the non-typical walking patterns associated with mobility impairments. Conventional linear statistical methods and machine learning (ML) models are commonly used to assess gait performance and related changes in the gait parameters. Nonetheless, explainable machine learning provides an alternative technique for distinguishing the significant and influential gait changes stemming from a given intervention. The goal of this work was to demonstrate the use of explainable ML models in gait analysis for prosthetic rehabilitation in both population- and sample-based interpretability analyses. Models were developed to classify amputee gait with two types of prosthetic knee joints. Sagittal plane gait patterns of 21 individuals with unilateral transfemoral amputations were video-recorded and 19 spatiotemporal and kinematic gait parameters were extracted and included in the models. Four ML models-logistic regression, support vector machine, random forest, and LightGBM-were assessed and tested for accuracy and precision. The Shapley Additive exPlanations (SHAP) framework was applied to examine global and local interpretability. Random Forest yielded the highest classification accuracy (98.3%). The SHAP framework quantified the level of influence of each gait parameter in the models where knee flexion-related parameters were found the most influential factors in yielding the outcomes of the models. The sample-based explainable ML provided additional insights over the population-based analyses, including an understanding of the effect of the knee type on the walking style of a specific sample, and whether or not it agreed with global interpretations. It was concluded that explainable ML models can be powerful tools for the assessment of gait-related clinical interventions, revealing important parameters that may be overlooked using conventional statistical methods.

Use of thioglycolate broth as a pre-analytic transport medium in the diagnosis of prosthetic joint infection.

This study aimed to investigate whether adding tissue samples directly into thioglycolate (TG) broth yielded a greater number of anaerobic organisms than freshly sampled tissue in suspected hip and knee prosthetic joint infections (PJIs). Between January 2017 and December 2020, a total of 90 patients (46 males, 44 females; median age: 71.7 years; range, 50.8 and 87.8 years) who underwent revision hip or knee arthroplasty were included. Intraoperative samples were taken, with five placed in TG broth and five in standard containers (PC) with subsequent aerobic and anaerobic culturing conducted. Demographic and baseline data of the patients were recorded. The primary outcome was positive bacterial growth from a PJI specimen inoculated directly into TG broth at the time of collection or standard PJI specimen processing. Secondary outcomes investigated were the presence of Cutibacterium acnes (C. acnes) and the curative success of revision procedure. A total of 900 samples (450 PC and 450 TG) were taken from 90 revision arthroplasty patients (47 knees and 43 hips). There was no statistically significant difference in the number of positive bacterial growth samples between TG broth and standard processing (p=0.742). This was consistent with subgroup analysis analyzing C. acnes (p=0.666). In hip and knee arthroplasty, there is no benefit in substituting or adding TG broth as a culture medium to better identify both general bacterial species and C. acnes infections specifically. However, the use of TG may be useful in confirming a true positive result for infection.

Genetic Algorithm with Lyapunov Stability for Control of Prosthetic Knee Joint

Genetic Algorithm with Lyapunov Stability for Control of Prosthetic Knee Joint

Dyslipidaemia is associated with Cutibacterium acnes hip and knee prosthetic joint infection.

Optimization of medical factors including diabetes and obesity is a cornerstone in the prevention of prosthetic joint infection (PJI). Dyslipidaemia is another component of metabolic syndrome which has not been thoroughly investigated as an individual, modifiable risk factor. This study examined the association of dyslipidaemia with PJI caused by the lipophilic microbe Cutibacterium acnes (C. acnes). A retrospective chart review examined patients with positive C. acnes culture at hip or knee arthroplasty explantation. A control group with methicillin-sensitive Staphylococcus aureus (MSSA) positive cultures at explantation was matched for age, sex, and surgical site, as well as a second control group with no infection. A total of 80 patients were included, 16 with C. acnes, 32 with MSSA, and 32 with no infection. All patients had a lipid panel performed within oneyear of surgery. Lipid values and categories were compared using multinomial logistic regressions. High or borderline triglycerides (TG) (relative risk ratio (RRR) = 0.13; P = 0.013) and low high-density lipoprotein (HDL) (RRR = 0.13; P = 0.025) were significantly associated with C. acnes PJI compared to MSSA-PJI. High or borderline TG (RRR = 0.21; P = 0.041) and low HDL (RRR = 0.17; P = 0.043) were also associated with a greater probability of C. acnes infection compared to no infection. The presence of elevated TG and low HDL were both associated at a statistically significant level with C. acnes hip or knee PJI compared to controls with either MSSA PJI or no infection. This may represent a specific risk factor for C. acnes PJI that is modifiable.

On the application of spatial four-bar motion and axode generation for the design of a prosthetic canine knee joint

The novelty of this work is that for the first time, spatial four-bar linkage motion generation and axode generation models have been applied for the design of a joint to replicate natural canine knee motion. This canine knee design method incorporates spatial four-bar Revolute-Revolute-Spherical-Spherical linkage motion generation and axode generation models to ultimately produce the rolling cam surfaces needed to produce natural spatial canine knee motion. This work presents the latest findings from an ongoing study where a transfemoral prosthetic knee design method is being applied to produce concept prosthetic knee joints for canines that replicate natural spatial knee motion during treadmill gait. To date, this study has considered three canine subjects, ranging from ages 1.1 to 10 years and treadmill speeds ranging from 1.3 to 2.9 km/h.

Frequent microbiological profile changes are seen in subsequent-revision hip and knee arthroplasty for prosthetic joint infection.

A proportion of patients with hip and knee prosthetic joint infection (PJI) undergo multiple revisions with the aim of eradicating infection and improving quality of life. The aim of this study was to describe the microbiology cultured from multiply revised hip and knee replacement procedures to guide antimicrobial therapy at the time of surgery. Patients and methods: Consecutive patients were retrospectively identified from databases at two specialist orthopaedic centres in the United Kingdom between 2011 and 2019. Patient were included who had undergone repeat-revision total knee replacement (TKR) or total hip replacement (THR) for infection, following an initial failed revision for infection. Results: A total of 106 patients were identified. Of these patients, 74 underwent revision TKR and 32 underwent revision THR. The mean age at first revision was 67years (SD 10). The Charlson comorbidity index was 2 for 31 patients, 3-4 for 57 patients, and 5 for 18 patients. All patients underwent at least two revisions, 73 patients received three, 47 patients received four, 31 patients received five, and 21 patients received at least six. After six revisions, 90 % of patients had different organisms cultured compared with the initial revision, and 53 % of organisms were multidrug resistant. The most frequent organisms at each revision were coagulase-negative Staphylococcus (36 %) and Staphylococcus aureus (19 %). Fungus was cultured from 3 % of revisions, and 21 % of infections were polymicrobial. Conclusion: Patients undergoing multiple revisions for PJI are highly likely to experience a change in organism, with 90 % of patients having a different organism cultured by their sixth revision. It is therefore important to administer empirical antibiotics at each subsequent revision, taking into account known drug resistance from previous cultures. Our results do not support the routine use of empirical antifungals.

Design and experiment of a variable stiffness prosthetic knee joint using parallel elastic actuation

Active prosthetic knee joints are proven to provide outstanding actuating performance in various walking situations. Currently, most active prosthetic knee joints are directly actuated via motors, which have the disadvantages of high-power consumption and insufficient joint compliance. In order to solve this problem, this paper proposed an active prosthetic knee joint with a unique variable stiffness parallel elastic actuation (VSPEA) mechanism. The VSPEA prosthetic knee joint is implemented by a geared five-bar mechanism with a motor-screw system. The VSPEA mechanism is implemented via another optimized compact motor-screw-spring system controlled by an adaptive stiffness adjustment algorithm. Numerical verifications show that the VSPEA prosthetic knee joint can reduce its actuation torque and power compared to the prosthetic knee joint without the VSPEA mechanism. Further practical experiments of the VSPEA prosthetic knee joint indicate that the Root Mean Square of its actuation motor power can decline 7.36 %, 8.75 %, and 11.51 % at 1.49 m/s, 1.21 m/s, and 0.85 m/s level-ground walking, respectively, which demonstrated that VSPEA could effectively reduce the energy consumption and improve the endurance of the prosthetic knee joint.

A rare first case of prosthetic knee joint infection by Citrobacter koseri

Citrobacter generally colonizes the gastrointestinal and urogenital tracts of humans, but musculoskeletal infection by Citrobacter in the elderly is extremely rare. To our knowledge, less than 15 cases of causing musculoskeletal infection have been reported in the literature. In the last few years, there has been a considerable increase in the incidence of prosthetic knee joint infection in the United States, with a higher risk of infection in the first two years following surgery. Although gram-positive bacteria like Staphylococcus and Streptococci are more common cause of PJI, gram-negative bacteria can also be found in infected joints. We report the first case of PJI in the left knee due to in an 82-year-old adult two years after bilateral knee arthroplasty. This case report intends to educate and raise awareness for causing PJI as a long term post-op complication even in healthy individuals. We searched articles on Pubmed and Medline for PJI and citrobacter infection. We report clinically and microbiologically confirmed in a synovial fluid sample of the left knee joint. should be considered as a possible pathogen for PJI in long term setting even in an otherwise healthy individual.

Short-term outcomes of articular cement spacer in the treatment of prosthetic knee joint infections: a retrospective case series.

Short-term outcomes of articular cement spacer in the treatment of prosthetic knee joint infections: a retrospective case series.

Outcome of debridement, antibiotics and implant retention for streptococcal hip and knee prosthetic joint infections: A systematic review and meta-analysis

Outcome of debridement, antibiotics and implant retention for streptococcal hip and knee prosthetic joint infections: A systematic review and meta-analysis

Fabrikasi Model Anatomi 3-D menggunakan 3-D Printing untuk Simulasi Proses Operasi Total Knee Replacement (TKR) berdasarkan Rekonstruksi Pemindaian CT/MRI sebagai Alat Edukasi dan Pelatihan

&lt;p&gt;&lt;em&gt;Currently, 3-D printing or additive manufacturing technology has been widely used to fabricate anatomical 3-D models of human body parts based on CT/MRI Scan reconstructions. Anatomical 3-D models resulting from 3-D printing have many applications, such as educational tools, specific implants, concepts of preoperative planning, etc. This research focuses on the reconstruction of the knee bones, modeling the Total Knee Replacement (TKR) prosthetic knee joint, and creating a 3-D anatomical model for TKR surgery simulation model using a fused deposition modeling (FDM) 3D print type. The results of the 3-D anatomical model using a 3D print can demonstrate a simulation of the TKR operation and installation according to the operating procedure with the limitation of the surgical process only to cutting the bone and inserting a prosthetic knee joint.&lt;/em&gt;&lt;/p&gt;