Total Knee Replacements

OBJECTIVE:

The external knee adduction moment (EAM) is often considered a surrogate measure of the distribution of loads across the tibiofemoral joint during walking. This study was undertaken to quantify the relationship between the EAM and directly measured medial tibiofemoral contact forces (Fmed ) in a sample of subjects across a spectrum of activities.
METHODS:

The EAM for 9 patients who underwent total knee replacement was calculated using inverse dynamics analysis, while telemetric implants provided Fmed for multiple repetitions of 10 activities, including walking, stair negotiation, sit-to-stand activities, and squatting. The effects of the factors "subject" and "activity" on the relationships between Fmed and EAM were quantified using mixed-effects regression analyses in terms of the root mean square error (RMSE) and the slope of the regression.
RESULTS:

Across subjects and activities a good correlation between peak EAM and Fmed values was observed, with an overall R(2) value of 0.88. However, the slope of the linear regressions varied between subjects by up to a factor of 2. At peak EAM and Fmed , the RMSE of the regression across all subjects was 35% body weight (%BW), while the maximum error was 127 %BW.
CONCLUSION:

The relationship between EAM and Fmed is generally good but varies considerably across subjects and activities. These findings emphasize the limitation of relying solely on the EAM to infer medial joint loading when excessive directed cocontraction of muscles exists and call for further investigations into the soft tissue-related mechanisms that modulate the internal forces at the knee

INTRODUCTION: Diseases of the locomotor system or musculoskeletal disease are on the rise, mainly due to the ageing of the population but also due to lifestyle changes. Those are the main cause of chronic pain and disability in the modern world. Thanks to the achievements of modern medicine, in patients with advanced osteoarthritis of the hip or knee it is possible to replace the diseased joint with an endoprosthesis, with very good long-term results related to pain reduction and function improvement. The aim of this study is to examine are there any differences in the quality of people's life before and after implantation of total knee endoprosthesis. RESPONDENTS AND RESEARCH METHODS: There were 30 subjects of both genders with knee joint disease enrolled in the study, who were treated with the surgical course at the Orthopedics clinic and the traumatology of the UKCS by implanting a total endoprosthesis, from the beginning of April until the end of October 2018. As an instruments of this research are used standardized SF-36 questionnaire for assessing the quality of life and overall health status and a modified questionnaire on the socio-demographic characteristics of the respondents. RESULTS: Patients after implantation of total knee endoprosthesis have a better quality of life, i.e. statistical significance at physical function level (P = 0.0001), role limits due to physical problems (P = 0.0001), social functions (p = 0.0001), energy or vitality (P = 0.0001), pain (p = 0.0001), limitations of the role due to emotional problems (P = 0.0001), and emotional prosperity (P = 0.0001) and general health (P = 0.004). CONCLUSIONS: The quality of life of patients was worse before the period after the total knee endoprosthesis, where statistically significant improvement was demonstrated.

Purpose Reproducing the femoral rollback through specially
designed mechanism in knee implants is required to
achieve full knee function in total knee arthroplasty. Most
contemporary implants use cam/post mechanism to replace
the function of Posterior Cruciate Ligament. This study
was aimed to determine the most appropriate cam and post
designs to produce normal femoral rollback of the knee.
Methods Three different cams (triangle, ellipse, and circle)
and three different posts (straight, convex, concave)
geometries were considered in this study and were analysed
using kinematic analyses. Femoral rollback did not
occur until reaching 50° of knee flexion. Beyond this angle,
two of the nine combinations demonstrate poor knee flexion
and were eliminated from the study.
Results The combination of circle cam with concave
post, straight post and convex post showed 15.6, 15.9 and
16.1 mm posterior translation of the femur, respectively.
The use of ellipse cam with convex post and straight post
demonstrated a 15.3 and 14.9 mm femoral rollback, whilst
the combination of triangle cam with convex post and straight post showed 16.1 and 15.8 mm femoral rollback,
respectively.
Conclusion The present study demonstrates that the use
of circle cam and convex post created the best femoral rollback
effect which in turn produces the highest amount of
knee flexion. The findings of the study suggest that if the
design is applied for knee implants, superior knee flexion
may be possible for future patients.
Level of evidence IV.

Total knee replacements (TKR) have been of great interest for over three decades. Loosening of tibial components has been identified as one of the primary causes of failures in early knee
replacement. Alignment and fixation techniques play an important role in achieving high success rates. About 27,000 knee replacements are carried annually in UK alone and revision knee surgery accounts for about 10-12% worldwide.
Defective bone stock requires the use of augments to stabilise the tibial plate. In these cases, current clinical practice is to use an extended implant stem to ensure stability. The problem with this is that it reduces the potential for future knee revisions. Biomechanical analysis of this procedure is being undertaken in order to determine best practice. The research will also include an analysis to compare the use of cement to fill the defected region rather than augments.
The report outlines the clinical studies; discussing various implants and different approaches to the modelling work. As part of the research, some modelling software packages were assessed. Detailed studies were performed to select a suitable package that allows the replication of clinically observed environments in static simulations. The report discusses the final modelling approach, and boundary conditions used to perform finite element analysis. Detailed stress and strain distributions have been obtained and the results show that the solution is a clinically acceptable working model.
This model can be modified to include varying material properties and densities to allow for
realistic simulation. Future work will involve modifying the model to include the augments,
different lengths of stem and a range of other clinically relevant parameters.

Knee Replacement Surgery is one of the best treatment options for knee diseases and conditions. The treatment of knee infection depends on the type and severity of the injury. Here are some important myths and facts on the lifestyle choices that affect joint health.

Introduction: Total knee replacement (TKR) is one of the most frequent orthopaedic procedures performed every year. At the same time 20% of patients who underwent TKR are not satisfied with the outcome. The reasons are unknown; we think that a mechanical alignment beyond 3° of varus-valgus can represent the most important cause of failure of TKR and consequently patient dissatisfaction. Materials and Methods: Neutral mechanical alignment is the main goal in every TKR: this can be achieved through different tools, such as extramedullary and intramedullary guides, patient-specific instrumentation (PSI) and computer assisted surgery (CAS). The aim of this review is to compare the different alignment techniques in TKR, to describe CAS procedure and CAS results in recent literature. Results: Regarding the intramedullary guide, there is an increased risk of fatty embolism; there are great limitations on its use, or even impossibility, in cases of bone deformity and sequelae of trauma. Regarding the extramedullary guide, it becomes more difficult to use in cases of great obesity or increased soft-tissue volume around the tibia. PSI for TKR has been introduced to improve alignment, reduce outliers, operation time and the risk of fatty embolism by avoidance of intramedullary canal violation. Recent randomized controlled trials and meta-analysis proved no advantage of PSI in improving mechanical axis and implant survivorship. Discussion: CAS has provided to be a useful tool in assisting the surgeon to achieve more accurate post-operative mechanical axis through precise and reproducible bone cuts and ligament balancing. Two meta-analyses definitively proved that CAS technique improves mechanical axis and implant survivorship and one recent meta-analysis demonstrated that CAS provides better mechanical alignment and higher functional scores at short-term follow-up. (www.actabiomedica.it)

An increased LOS and undesired outcomes fall to be a burden physically and mentally for such patients, and so they should be previously educated on the expected outcomes. Nonetheless, the importance of these factors on the decision to perform knee arthroplasty is debatable among surgeons.

The Anterolateral Ligament (ALL) of the Knee was recently discovered. 
ALL has been considered as a prime stabiliser of the rotational instability of the knee . There is no complete consensus about its anatomy .The purpose of this study is to compare mechanical properties of ALL and IlioTibial Tract (ITT). The specimens were embalmed with a new product. A membranous structure (ALL) cross anterior to the gain of FCL and stretched with combined varus, flexion and internal rotation of the knee. Two tests were carried out for a relaxation test and an elongation test to identifies non-linear behaviour and behaviour at rupture .ITT found to be 6 times more resistant to large strain than that ALL but its damage and its rupture occur at strain 3 and 2 times smaller, respectively. Average Young Modulus for ITT is 225.7 ± 99.4 and for ALL is 38.15 ± 52.98.
This is the prefinal copy .

""Purpose: Flexion contracture has been shown to impair function and reduce satisfaction
following total knee arthroplasty (TKA). The aim of this study was to identify modifiable
intra-operative variables that predict post-TKA knee extension.
Methods: Data was collected prospectively on 95 patients undergoing total knee arthroplasty,
including pre-operative assessment, intra-operative Computer Assisted Surgery (CAS)
measurements and functional outcome including range of motion at 1 year. Patients were
divided into two groups: those with mild flexion contracture (> 5°) at the 1 year and those
achieving full extension.
Results: The sagittal orientation of the distal femoral cut differed significantly between
groups at the 1 year follow-up (p = 0.014). Sagittal alignment of greater than 3.5° from the
mechanical axis was shown to increase the relative risk of a mild flexion contracture at 1 year
follow-up by 2.9 times, independent of other variables.
Conclusion: Increasing the sagittal alignment of the distal femoral cut more than 3.5 degrees
from the mechanical axis is an independent risk factor for clinically detectable mild flexion
contracture 1 year from index procedure.""

Total knee replacement is the fastest growing "High Cost" or-thopedic surgery in the world [1]. In India, the per annum knee replacements have multiplied thirty times in the last decade [2]. With such large numbers of knee replacements being performed regularly, many of them on patients younger than 55 years, it is logical that in years to come, there will arise a need for a large number of revision surgeries, which are far more complex and costlier than the index primary surgery [3]. With total knee replacement TKR surgery being covered by all insurance schemes, including the government schemes [4], younger surgeons are in a rat race to perform this surgery even on those patients on whom it is not indicated. Camps are being held and public awareness campaigns are being run by orthopedic surgeons and hospitals extolling the benefits of this procedure, and warning the patients of the perils of its delay (Figure 1). However the risks, complications, and the natural history of the artificial knee joints are seldom discussed in detail with the pa-Figure 1: Knee replacement is an aggressively promoted surgery. tients. Likewise few surgeons inform the younger patients about the finite life of the artificial knee, and the extremely high cost, technical skills and infrastructure needed for revision knee replacements. This results in a situation where near normal knees are replaced for minimal symptoms without any attempts at restoration or preservation of the joint. Despite the fact that logic tells us that a natural knee is always preferable to an artificial one, the number of surgeons engaged in preservation and restoration are far fewer than the primary arthroplasty surgeon. Arthroplasty today is a glamorous sub specialty and most young trainees aspire to be a replacement surgeon, rather than a restoration/preservation surgeon. The X-ray in figure 2 shows a pre and post operative X-rays of both knees of a doctors mother which underwent replacement. Though the post operative radiograph has nothing to criticize on technical grounds, a look at the preoperative X-ray will clearly indicate that the patient is suffering from only very early minimal medial compartment OA of the knee. Such knees should not be replaced. Figure 2: A knee replacement has been performed on a near normal knee which could have been managed better by other lesser invasive methods.

Neuroimaging studies, using various modalities, have evidenced a link between the general intelligence factor (g) and regional brain function and structure in several multimodal association areas. While in the last few years, developments in computational neuroanatomy have made possible the in vivo quantification of cortical thickness, the relationship between cortical thickness and psychometric intelligence has been little studied. Recently, cortical

""Background: The position of the femoral component in total knee arthroplasty (TKA) in the axial plane is important in ensuring good functional outcome and avoiding early revision. A number of methods of guiding femoral component rotation at the time of implantation are described. The functional flexion axis (FFA) of the knee is a kinematically derived reference axis which can be determined intra-operatively by a computer navigation system as an alternative method of guiding femoral component rotation. 
Question/purposes: (1) Can the FFA be measured reliably and reproducibly? (2) Where does it lie in relation to more traditional methods of judging femoral component rotation?
Methods: Thirty seven patients undergoing elective TKA were recruited to the study. Preoperative CT scans were obtained and identified the trans-epicondylar axis (TEA). TKA was then performed using computer navigation. The FFA was derived before incision and again following the surgical approach and osseous registration. The navigation system was used to register the surgical trans-epicondylar axis. The FFA and surgical TEA were then compared to the CT-derived TEA.
Results: The mean  pre-incision FFA was found to be similar to the intra-operative FFA and therefore deemed reproducible. No differences were seen in patient variability between surgical TEA and pre-incision FFA. Both FFA and surgical TEA were different from the CT-TEA and deemed to be of similar accuracy.
Conclusion: Further evaluation is required to ascertain whether the FFA adds to currently available methods for determining the ideal rotation of the femoral component during TKA. 
""

This examines knee biomechanics in terms of patient function, prosthesis design, cruciate ligament retention, alignment, and fixation of the tibial component. While design and surgical technique for total knee replacement progress, a better understanding of the characteristics of joint loading, stress distribution, and the biologic response of bone to stress will provide the potential to improve both function and implant longevity.

In this routine procedure, the worn out cartilage forming the knee are trimmed and chamfered to allow for insertion of a metallic cap and tray articulating with one another through a highly resistant low friction plastic (polyethylene) cartridge insert. This artificial knee helps the patient in their everyday movement and usually last for long durations.
The material is light therefore there is a good chance of it giving away under intense stress, therefore the patients are asked to keep to as little movement as they can. The patient satisfaction success rate of the operation is high, but is critically dependent on diligent post operative cooperation with exercises and physiotherapy.

This study involves the failure analysis of an ultra high molecular polyethylene (UHMWPE) tibial insert from Apollo® Total Knee System, which was removed after 10. years of service from 70. years old female patient. The tibial insert was investigated by using a stereoscope, scanning electron microscope (SEM), infinite focus microscope (IFM) and energy disperse spectroscopy (EDS) to characterize the morphology and composition of the bearing surface. Differential scanning calorimetry (DSC) and Fourier transform spectroscopy (FTIR) were employed to characterize the degradation and crystallinity of the component. Gel-permeation chromatography (GPC) was used to measure the polyethylene tibial insert molecular weight. Results showed that the failure of total knee replacement (TKR) was associated with high grade wear and oxidation degradation. Surface delamination, scratch marks, pitting, folding, and embedded third body particles were observed on the retrieved UHMWPE tibial surface. Pit depth as large as 60 μm was measured on the surface. The damage features observed on the UHMWPE tibial insert suggested degradation is due to fatigue related wear and is oxidation-induced. Overall results show that the UHMWPE tibial insert which was retrieved from a patient who is active and but not overweight underwent degradation of material properties and high grade wear during 10. years of service.

http://www.sciencedirect.com/science/article/pii/S1350630711000999

PURPOSE:

Data on the association between body mass index (BMI) and risk of knee osteoarthritis (KOA) are sparse for Asian populations who are leaner than Western populations. We evaluated the association between BMI and risk of total knee replacement (TKR) due to severe KOA among Chinese in Singapore.

METHODS:

We used data from the Singapore Chinese Health Study (SCHS), a population-based prospective cohort of 63,257 Chinese men and women, aged 45-74 years at enrollment from 1993 to 1998. Information on height, weight, diet and lifestyle factors were obtained via in-person interviews. TKR cases for severe KOA were identified via linkage with the nationwide hospital discharge database through 2011. Cox regression and weighted least squares regression were used in the analysis.

RESULTS:

The mean BMI among cohort participants was 23.1 kg/m(2), and more than two-thirds had BMI below 25 kg/m(2). A total of 1649 had TKR attributable to severe KOA. Risk of TKR increased in a strong dose-dependent manner with increasing BMI throughout the 15-32 kg/m(2) range and became less clear at BMI >32 kg/m(2). In the BMI range 16-27 kg/m(2), there was a 27% increase in TKR risk for each unit increase in BMI (P for trend < 0.001). Compared to BMI 19-20 kg/m(2), the risk estimates of TKR were all statistically significant with increasing unit of BMI ≥21 kg/m(2). Results were similar for men and women.

CONCLUSION:

Our results provided evidence for a constant mechanical mechanism underlying BMI and KOA initiation and/or progression.

Osteoarthritis is a disease caused by loss of cartilage tissue, which acts as a cushion to protect the ends of bones and helps the movement of the joint. It is the most common rheumatic disease, especially among older people and affects more women than men. Knee osteoarthritis has produced particular interest in latest years because it has become one of the major causes of physical disability in both men and women worldwide.
This project aimed to obtain a 3D model of the knee of a patient affected by osteoarthritis, based on specific medical images and then print a prototype of the knee. For this, using a database containing medical images provided by OAI, the study containing the sharpest and best for processing images was selected. Then, working with the study, the bone part of the knee was properly segmented using a software called 3D Slicer. After segmentation, files needed for printing the desired prototype were generated.
After all, it was concluded that it is possible to segment a knee with osteoarthritis using actual patient medical images and then print a 3D prototype that can be used in future analyzes.

Mechanical breathing technology has evolved over centuries. In the 1530s, a fireplace bellows connected to a tube placed in a patient's mouth marked the first attempt on record of ventilation by mechanical means. The earliest body-enclosing respirator was patented in America in 1864 and by 1876 the 'spirophore,' the first functional ventilator, was designed featuring the basic elements of later 'iron lungs' including a metal tank, sliding bed and adjustable rubber collar. The J.H. Emerson Company followed with a practical and commercially viable iron lung allowing hospitals throughout the world to have a standard respirator with replaceable parts.

TKR in Ahmedabad, Total Knee Replacement & Shoulder Surgeon in Ahmedabad. Our team of renowned professionals offers a variety of Treatments.

TOTAL KNEE REPLACEMENT
This specialized type of surgery has helped millions of mostly old people worldwide. Increasing age brings in many diseases and a sedentary lifestyle adds to the troubles. A combination of overweight, osteoporosis, cartilage wear and tear, arthritis, and so on lead to gradually increasing pain in the knees. While medicines and physiotherapy reduce pain in the beginning, total knee replacement [TKR] is the only permanent solution for painful knees.

DIFFERENT TYPES OF TKR ARE:
Primary Total Knee Replacement
Revision Knee Replacement
Uni-condylar Knee Replacement [only one part of the knee is replaced]

TOTAL HIP REPLACEMENT
Osteoarthritis of the hip joint
Hip injuries
Rheumatoid arthritis
Bone tumor or
Avascular Necrosis: aka AVN, it occurs because of insufficient blood supply

THR MUST BE DONE WHEN
Pain that keeps you awake at night
Little or no relief from pain medications
Difficulty walking up or down the stairs
Trouble standing up from a seated position
Avoiding walking because of pain

Background Studies have highlighted asymmetries in knee joint moments during activities of daily living in individuals with osteoarthritis and joint replacements. However, there is a need to investigate the forces at the knee joints in order to establish the extent of loading asymmetry. Methods Twenty healthy (mean, 62; range, 55-79 years of age) and 34 pre-to post-knee arthroplasty (mean, 64; range, 39-79 years of age) participants performed gait and sit-stand activities in a motion capture laboratory. Testing was conducted 4 weeks pre-and 6 months post-knee arthroplasty. Knee joint forces and moments were predicted using inverse dynamics and used to calculate peak loading and impulse data which were normalized to body weight (BW). Comparisons were made in loading between affected and contralateral limbs, and changes from pre-to post-knee arthroplasty. Findings Pre-knee arthroplasty mean peak vertical knee forces were greater in the contralateral limb compared to the affected limb during both gait 3.5*BW vs. 3.2*BW and sit-stand 1.8*BW vs. 1.5*BW. During gait, peak knee adduction moment asymmetries significantly changed from pre-to post-knee arthroplasty (-0.3 to 0.8*% BWm.Ht), although differences in vertical knee forces remained. The sit-stand activity showed vertical ground reaction asymmetries slightly increased post-knee arthroplasty (from 0.06*BW pre-to 0.08*BW post). The healthy participants showed no noteworthy asymmetries. Interpretation This study showed loading asymmetry of the ground reaction and TFJ forces between affected and contralateral limbs both pre-post-knee arthroplasty. Over reliance of the contralateral limb could lead to pathology.

Background: The available literature on the reported patient satisfaction following bilateral staged primary total knee arthroplasty (TKA) is limited. The purpose of our study is to compare patient-reported satisfaction following bilateral non-simultaneous TKA performed
in a single unit.
Methods: We retrospectively analyzed our regional database, the Trent and Wales Arthroplasty Audit Group (TWAAG). Patients who had bilateral staged TKA in the University Hospitals of Leicester, UK, between 1990 and 2007 and had completed a 12-month post-operative questionnaire were included in the study.
Results: One thousand one patients were included in the study. 824 patients (82.3%) reported being satisfied with both of their primary
TKAs. 91% and 88% reported being satisfied with their TKA respectively for the first and second sides. A chi-squared test revealed that the difference in satisfaction rates between the first and second side TKA was statistically significant. 86 patients were pleased with their first side but not pleased/unsure with the second side. On the other hand, 55 patients were pleased with their second side but not pleased/unsure with the first side. This difference was also statistically significant.
Conclusion: In our study, more patients were pleased following their first side compared to their second side TKA.

Background and purpose Although a tourniquet may reduce bleeding during total knee replacement (TKA), and thereby possibly improve fixation, it might also cause complications. Migration as measured by radiostereometric analysis (RSA) can predict future loosening. We investigated whether the use of a tourniquet influences prosthesis fixation measured with RSA. This has not been investigated previously to our knowledge. Methods 50 patients with osteoarthritis of the knee were ran-domized to cemented TKA with or without tourniquet. RSA was performed postoperatively and at 6 months, 1 year, and 2 years. Pain during hospital stay was registered with a visual analog scale (VAS) and morphine consumption was measured. Overt bleeding and blood transfusions were registered, and total bleeding was estimated by the hemoglobin dilution method. Range of motion was measured up to 2 years. Results RSA maximal total point motion (MTPM) differed by 0.01 mm (95% CI –0.13 to 0.15). Patients in the tourniquet group had less overt bleeding (317 mL vs. 615 mL), but the total bleeding estimated by hemoglobin dilution at day 4 was only slightly less (1,184 mL vs. 1,236 mL) with a mean difference of –54 mL (95% CI –256 to 152). Pain VAS measurements were lower in the non-tourniquet group (p = 0.01). There was no significant difference in morphine consumption. Range of motion was 11° more in the non-tourniquet group (p = 0.001 at 2 years). Interpretation Tourniquet use did not improve fixation but it may cause more postoperative pain and less range of motion.

total knee arthroplasty patient-specific instrumentation navigation accuracy This investigation evaluated the Smith and Nephew VISIONAIRE patient-specific cutting block (PSCB) system for total knee arthroplasty. A consecutive series of 60 patients was recruited. Intraoperative computer navigation was used to evaluate the accuracy of the cutting blocks in the coronal and sagittal planes for the tibia, as well as rotational plane for the femur. The PSCB would have placed 79.3% of the sample within ±3°of the preoperative plan in the coronal plane, while the rotational and sagittal alignment results within ±3°w ere 77.2% and 54.5% respectively. The VISIONAIRE PSCB system achieved unacceptable accuracy when assessed by computer navigation. There might be many sources of error, but caution is recommended before using this system routinely without objective verification of alignment.

Background: Mobile-bearing knee designs represent an alternative to conventional fixed-bearing implants in total knee arthroplasty. The purpose of this study was to determine the clinical results of a mobile-bearing knee implant. Methods: From 1990 to 1998, 326 primary consecutive mobile-bearing total knee prostheses were implanted in 260 patients who had a mean age and standard deviation of 66.7 ± 6.9 years. Femoral and tibial components were cemented in all knees, and the patella was resurfaced in 199 knees (61%). Patients were evaluated with the use ofthe Knee Society clinical rating system and radiographie examinations. Complications were noted, and survivorship ofthe prostheses was determined. Results: The mean follow-up period was 156 ± 27.3 months, with maximum follow-up at eighteen years. The mean Knee Society knee score improved from 32.4 ± 21.2 preoperatively to 92.6 ± 10.0 at the time of the last follow-up (p = 0.00), and the mean Knee Society functional score improved from 39.3 ± 18.7 preoperatively to 66.7 ± 18.6 at the time of the last follow-up (p = 0.00). Mean knee flexion improved from 92.3° ± 14.5° preoperatively to 112.1° ± 13.4° at the time of the last follow-up (p = 0.00). There were twenty-four (7.4%) knees that required revision. In eighteen (5.5%) knees, worn out or broken polyethylene was found and a polyethylene-only exchange was done. Six knees (1.8%) were fully revised. The survival rate was 0.96 (95% confidence interval, 0.93 to 0.98) at ten years and 0.87 (95% confidence interval, 0.79 to 0.93) at eighteen years. Conclusions: A fully congruent, mobile-bearing total knee prosthesis had excellent survivorship during the ten to eighteenyear follow-up interval.

Total knee replacements (TKR) have been of great interest for over three decades. Loosening of tibial components has been identified as one of the primary causes of failures in early knee replacement. Alignment and fixation techniques play an important role in achieving high success rates. About 27,000 knee replacements are carried annually in UK alone and revision knee surgery accounts for about 10-12% worldwide. Defective bone stock requires the use of augments to stabilise the tibial plate. In these cases, current clinical practice is to use an extended implant stem to ensure stability. The problem with this is that it reduces the potential for future knee revisions. Biomechanical analysis of this procedure is being undertaken in order to determine best practice. The research will also include an analysis to compare the use of cement to fill the defected region rather than augments. The report outlines the clinical studies; discussing various implants and different approaches to the modelling work. As part of the research, some modelling software packages were assessed. Detailed studies were performed to select a suitable package that allows the replication of clinically observed environments in static simulations. The report discusses the final modelling approach, and boundary conditions used to perform finite element analysis. Detailed stress and strain distributions have been obtained and the results show that the solution is a clinically acceptable working model. This model can be modified to include varying material properties and densities to allow for realistic simulation. Future work will involve modifying the model to include the augments, different lengths of stem and a range of other clinically relevant parameters.

Aim: Early research found innate immune factor complement C3 in the synovial fluid (SF) and activated in serum of osteoarthritis (OA) patients. Whether synovial C3 comes from circulation, or is produced locally, is still unknown. It is also unclear whether synovial and circulating C3 is responsible to OA symptoms. A native C3 molecule consists of two chains, C3-α and C3-β. Small fragments breaking down from C3-α chain in serum and SF were reported to be related to OA severity. Little is known if C3-β chain is involved in the pathogenesis.

Method: In this study, we evaluated these important areas by biochemical analyses of C3-α and C3-β chains in both the SF and plasma of OA patients.
Results: Our results showed that C3-α and C3-β levels in SF did not correlate with those in plasma, suggesting that synovial C3 is independently and locally produced, rather than being “leaked” from circulation. Synovial C3-β but not C3-α levels correlated with pain, other OA symptoms, function in daily living, and sports/recreational activities. Plasma C3-β levels only marginally correlated with pain, and plasma C3-α
levels did not correlate with any of these OA symptoms.

Conclusion: We present first-hand evidence that the clinical symptoms of OA are mainly associated with C3 in the local SF rather than systemic circulation, suggesting local factors in the etiopathogenesis. Future local targeted therapies for pain management may be more effective and safer.

KEYWORDS
complement, innate immunity (basic sciences), osteoarthritis, pain, symptom

https://onlinelibrary.wiley.com/doi/abs/10.1111/1756-185X.13794

BACKGROUND: Bringing together generic and heart failure (HF)–specific
items in a publicly available, patient-reported outcome measure may
facilitate routine health status assessment for improving clinical care
and shared decision-making, assessing quality of care, evaluating new
interventions, and comparing groups with different conditions.
METHODS AND RESULTS: We performed a mixed-methods study to
develop and validate the PROMIS®-Plus-HF (Patient-Reported Outcomes
Measurement Information System®-Plus-Heart Failure) profile measure—a
HF-specific instrument based on the generic PROMIS. We conducted
8 focus groups with 61 patients with HF and phone interviews with
10 HF clinicians. The measure was developed via an iterative process
of reviewing existing PROMIS items and developing and testing new
HF items. In a 600-patient sample, we estimated reliability (internal
consistency; test-retest, with n=100 participants). We conducted validity
analyses using Pearson r and Spearman ρ correlations with Kansas City
Cardiomyopathy Questionnaire subscores. In a longitudinal sample, we
performed responsiveness testing (paired t tests) with 75 patients with
HF receiving interventions with expected health status improvement. The
PROMIS-Plus-HF measure comprises 86 items (64 existing; 22 new) across
18 domains. Internal consistency reliability (Cronbach α) coefficients
ranged from 0.52 to 0.96, with α≥0.70 in 12 of 17 domains. Test-retest
intraclass correlation coefficients were ≥0.90. Correlations with Kansas
City Cardiomyopathy Questionnaire subscores supported expected
convergent (r/ρ>0.60) and divergent validity (r/ρ<0.30). In the longitudinal
sample, 10 of 18 domains had improved (P<0.05) scores from baseline to
follow-up.
CONCLUSIONS: The PROMIS-Plus-HF profile measure—a complete
assessment of physical, mental, and social health—exhibited good
psychometric characteristics and may facilitate patient-centered care and
research. Subsets of domains and items can be used depending on the
clinical or research purpose.

Background. The fit of the allograft is a particular concern in FOCA surgery. Digital design and fabrication were utilized in conjunction with traditional surgery to enable efficient discovery and reproduction of appropriately dimensioned allograft.
Materials and methods. A patient with large osteochondral defects in the lateral femoral condyle was to undergo FOCA surgery. A digital virtual operation was performed, based on computed tomography images of the patient. Polyamide saw templates were manufactured using a selective laser sintering process, and gypsum powder was used to manufacture preoperative and intraoperative medical models with binder jetting process. The design dimensions were verified numerically by determining the intactness of the section surface and allograft volume based on four independent measurements of the initial design, and an automated design optimization strategy was postulated. For the surgery, a lateral longitudinal approach was employed.
Results. The virtual operation allowed an efficient design of the saw templates. Their shape and dimensions were verified with a numerical CT analysis method. The allograft dimensions (med.lat./sup.inf./ant.post.) were approximately 40/28.5/24 mm, respectively, with the anterosuperior corner diagonally removed, yielding a section volume of approximately 16.5 cm3. These manually chosen dimensions were reminiscent of the corresponding computationally optimized values.
Conclusions. Use of computer-aided design and manufacture in virtual operation planning and 3D printing in the fabrication of designed templates allowed for an efficient FOCA procedure and accurate allograft fitting. The numerical optimization method allowed for a semiautomated design process, which can in turn be realized also with surgical navigation or robotic surgery methods.

A prospective study of 107 consecutive patients awaiting total knee or total hip arthroplasty found that 22.4% had positive Doppler Ultrasound evidence of pre-operative asymptomatic DVT and 9.3% had both positive sonographic and D-dimer evidence this, which calls into question the appropriateness of pharmacological post-operative DVT prevention and treatment, in addition to its investigation. AIMS: Total knee arthroplasty (TKA) and total hip arthroplasty (THA) have traditionally been associated with a post-operative risk of venous thrombo-embolism (VTE). However, the extent of this risk is not clearly defined, particularly in the context of modern surgical techniques and rehabilitation. Chemo-prophylactic and therapeutic agents used in the management of deep vein thrombosis (DVT) are themselves not without risk. Therefore, this study aims to determine the pre-operative incidence of asymptomatic DVT amongst patients listed for TKA or THA, which may shed light on the appropriateness of DVT prevention and treatment protocols in these individuals. METHODS: We prospectively performed pre-operative, bilateral, lower limb Doppler ultrasound scans (USS) on 107 consecutive patients listed for primary TKA or THA. Exclusion criteria consisted of concurrent anti-coagulation or a previous history of DVT. Both radiologists and sonographers were involved in undertaking the US examinations. Patients with evidence suggestive of DVT went on to have a D-dimer blood test, which if positive resulted in commencement of anti-coagulation therapy and postponement of surgery.

Background: Total knee arthroplasty (TKA) is one of the most effective surgical interventions for pain relief and functional recovery in young patients with rheumatoid arthritis, ankylosing spondylitis, traumatic arthritis, osteoarthritis knee, hampering the daily activities in life. The encouraging TKA results have prompted a growth in TKA utilisation, particularly in younger patients and a move away from procedures such as osteotomy and UKA which have been associated with higher re-operation rates. Over the last 2 decades there has been an increasing tendency toward the use of TKA in young adults, with some countries reporting a 5-fold increase in the last 10 years. Material and Method: This study was done on the patients who underwent total knee arthroplasty (37) at MGM medical college and hospital, Kamothe, Navi Mumbai. Out of 37 patients, 6 patients did not followed up at regular interval. Only 31 patients were included in the study (18 females and 13 males) fulfilling the inclusion and exclusion criteria. Total 50 knee were included in this study. Results: This study includes 31 cases fulfilling the inclusion and exclusion criteria with total 50 knees undergoing TKA. The mean age was 46.5 years. The functional outcome was calculated using knee society score. The average knee society score was 70.5 after 6 month post TKA while it was 80.5 after 1 year with reduced pain upto 6 month and almost no pain after 1 year. Three patients were seen with MRSA positive results and were operated after been treated with mupirocin. Two patients showed superficial skin infection following TKA. Conclusions: The total knee arthroplasty is one of the most successful and patient satisfactory surgical procedure in young patients relieving pain and daily activities in life as compared to old age patients undergoing TKA. In our study we have seen that it had provided the stability and promising result, by providing back the ability to carried out daily activities by own self after undergoing TKA in young patients who were facing problems in carrying out their daily activities by providing good outcomes as measured by knee society score as compared to older patients undergoing TKA.

1 2 This is a pre-review version of the manuscript: 3 4 Strickland, M. A., C. T. Arsene, et al. (2010). "A multi-platform comparison of 5 efficient probabilistic methods in the prediction of total knee replacement 6 mechanics." Comput Methods Biomech Biomed Engin 13(6): 701-709. 7 8 ABSTRACT 54 Explicit finite element (FE) and multi-body dynamics (MBD) models have been developed to evaluate total 55 knee replacement (TKR) mechanics as a complement to experimental methods. In conjunction with these 56 models, probabilistic methods have been implemented to predict performance bounds and identify important 57 parameters, subject to uncertainty in component alignment and experimental conditions. Probabilistic 58 methods, like Advanced Mean Value (AMV) and Response Surface Method (RSM), provide an efficient 59 alternative to the gold standard Monte Carlo Simulation Technique (MCST). The objective of the current 60 study was to benchmark models from 3 platforms (2 FE and 1 MBD) using various probabilistic methods by 61 predicting the influence of alignment variability and experimental parameters on TKR mechanics in 62 simulated gait. Predicted kinematics envelopes were on average about 2.6 mm for anterior-posterior (AP) 63 translation, 2.9 o for internal-external (IE) rotation and 1.9 MPa for peak contact pressure for the various 64 platforms and methods. Based on the good agreement with the MCST, the efficient probabilistic techniques 65 may prove useful in the fast evaluation of new implant designs, including considerations of uncertainty, e.g. 66 misalignment. 67 68

Background Osteoarthritis of the knee causes significant
disability amongst the elderly, and total knee replacement
remains the only effective intervention for pain relief and
functional improvement. Using data from single military
healthcare institutional records in India, we estimated the
utilization rates of total knee replacement by age, gender
and rank profile.
Methods All the data were retrieved manually from institutional
records as the institutional databases are yet to be
digitized. The information on the study subjects was retrospectively
retrieved from the records of the Department of
Orthopaedics from the year 1997 to 2012. Trends were
estimated by using two 6-year periods separated by a decade,
i.e. 1997–2002 and 2007–2012. We estimated age-, genderand
rank-specific rates of TKR utilization in these years.
Results From 1997 to 2002, 37 TKRs were performed as
compared to 800 during 2007–2012, showing a more than
20 times increase. During 1997–2002, the mean age was
62.6 years (SD—9.224) compared to 65.8 years (SD—
7.05). There was significant disparity in TKR utilization
rates on the basis of rank with officers and their dependent,
showing much higher utilization rates in both year groups
which is possibly explained by the higher level of awareness
about the procedure, higher education levels and
higher acceptability of the procedure by the officers as
compared to PBORs. The rate of TKR was marginally
higher amongst women as compared to men.
Conclusion The TKR utilization rates have increased
tremendously over a decade. In view of this huge increase,
future planning is essential to enable optimal material and
human resource allocation as well as training to meet future
challenges.