Introduction. Patients undergoing total knee arthroplasty (TKA) with end-stage osteoarthritis of knee have secondary foot and ankle pathology. Some compensatory changes occur at ankle and subtalar joint secondary to malalignment and deformity at the knee joint. Purpose was to evaluate the changes in hindfoot malalignment and foot deformities in patients with advanced osteoarthritis of knee requiring TKA and effect of correction of knee deformities post TKA on foot/Ankle alignment. Methods. 61 consecutive patients with Kellgren-Lawrence grade IV osteoarthritis knee undergoing TKA were enrolled in a prospective blinded study. Demographic data, deformities at knee and ankle, hindfoot malalignment and functional outcome scores such as VAS, KSS, WOMAC scores, Foot and Ankle Disability Index (FADI) and Foot posture index (FPI) were recorded preoperatively and postoperatively at 6, 12 weeks and final follow up (range: 6–21 months; mean: 14.2months). Results. Statistically significant improvement was observed in KSS score, WOMAC score, FADI and FPI after TKA. There was improvement in ankle valgus after correction of knee varus deformity. Hind foot changes mainly occured at subtalar joint. Hallux valgus (10 patients), and Pesplanus (5 patients) were associated with advanced osteoarthritis of knee. Gait profile score and Gait deviation index improved significantly after TKA. There was increased stance phase and decreased stride length in knee osteoarthritis patients which improved after TKA. Conclusion. Hind foot malalignment with foot deformities (hind foot valgus) occur secondary to knee malalignment and deformities (varus deformity) in advanced osteoarthritis of knee which subsequently improve following TKA

We have utilized arthroscopic arthroplasty of the hip joint (arthroscopic partial resection of the acetabular edge) for the treatment of advanced osteoarthritis of hip joint. We have utilized arthroscopic Arthroplasty to widen the joint space and tried to improve the outcome of joint preserving operation. We have treated advanced osteoarthritis of nine hip joints of eight patients (age from 41 to 56, averaged 44.3 years old) by arthroscopic arthroplasty in the past six years. The patient was put on the surgical traction table in the supine position. Arthroscope was inserted into the hip joint from antero-medial approach under fluoroscopic control and the acetabular edge was shaved until bleeding from subchondral bone was seen. In eight joints of seven patients, additional surgical procedures were applied later. Acetabular edge resection alone might resulted in the lateral-proximal displacement of the femoral head and to acquire good result in the long term, some additional procedure should be considered. However, in one case of this series showed good roof osteophyte formation after arthroscopic arthroplasty with improved JOA score. This might be a result of improved blood supply at the edge of acetablum. We believe that arthroscopic arthroplasty for advanced osteoarthritis in combination with other procedures may avoid total hip arthroplasty

Purpose. To examine measurement properties of four disability outcomes in patients with advanced osteoarthritis of the glenohumeral joint. Methods. This was a prospective longitudinal study of patients with advanced osteoarthritis of the glenohumeral joint who underwent a Total Shoulder Arthroplasty (TSA) and were followed for 6 months. Four measures [Western Ontario Osteoarthritis Shoulder (WOOS) Index, the American Shoulder and Elbow Surgeons (ASES) assessment, Constant-Murley score (CMS), and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH)] were completed 2-3 weeks before surgery and at 6 months after surgery. Results. Seventy-seven patients (average age: 66, range 35 to 86, 60% women, 40% men) participated in the study. The Cronbach's Coefficient Alpha of subjective measures was high at 0.91, 0.86, and 0.83 for WOOS, ASES, and QuickDASH respectively. All measures were able to discriminate between men and women's levels of disability at p< 0.05. Correlations between pre-operative scores were moderate (0.59 to -0.79) and slightly increased post-operatively (0.61 to -0.87). All measures were sensitive in detecting change in the disability status over a period of 6 months. Conclusion. All four disability measures were reliable and valid for use in patients with advanced osteoarthritis of the glenohumeral joint. Outcome measurement in busy clinics can be facilitated by choosing valid and reliable measures that have the advantage of simplicity for use by patients and clinicians. The consensus-based standards for selection of outcome measures have been developed for hip and knee arthritis and need to take place for the shoulder joint. Developing consensus by an international group of experts will improve consistency in using outcome measures in patients with shoulder problems

Advanced osteoarthritis of knee is associated with low-backache in a significant number of patients and adversely affects the quality of life. There is a paucity of literature describing outcomes of backache after total-knee-arthroplasty (TKA). We evaluated backache in patients of advanced knee-osteoarthritis and their functional and radiological outcomes after TKA after approval from Institutional ethics committee. Fifty-nine patients (40 females and 19 males) were included. Mean body-mass index was 28.7. Mean visual analogue score (VAS) for knee-pain was 7.98 preoperatively and 1.6 in follow-up. For chronic backache, the mean VAS score improved from 6.08 to 2.4, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) improved from 67.5 to 37.8, Knee society score (KSS) from 49.8 to 76.6, Oswestry Disability Index (ODI) Score from 55.44 to 34.65 and SF-36 Quality-of-life score from 44.95 to 74.63. There was a significant correlation between in knee and low-back functional scores. Magnetic resonance imaging-based scoring of degenerative changes (Pfirrmann grading) showed improvement only in 13.5% patients; 56% showed no change and 30.5% showed deterioration of scores. Chronic low backache is a significant co-morbidity in advanced knee-osteoarthritis. TKA has the potential to relieve backache along with knee-pain and improves quality of life

Introduction and Aim

Quadriceps strength is crucial for physical function in patients with knee osteoarthritis (KOA). This study aimed to investigate the effect of combining blood flow restriction (BFR) with low-intensity training (LIT) on quadricep strength in patients with advanced KOA.

Introduction and Aims: Establishing pathogenic mechanisms that are important for OA progression would support development of therapies to delay arthoplasty and extend the life of the joint. The aim of this study was to define a human model system for comparing minimal and advanced OA cartilage at the tissue, cellular, and molecular level.

Method: Cartilage was isolated from femoral condyles of patients undergoing knee arthroplasty, with advanced OA cartilage obtained from areas within 1cm of overt lesions, and minimal OA cartilage taken from areas with no obvious surface defects. Representative histological sections were scored for disease severity based on four categories: fibrillation, chondrocyte cloning, matrix depletion and cellularity using Bioquant Nova v5.00.8 software. The proteoglycan and hydroxyproline content of the cartilage was determined by biochemical analysis. Following RNA isolation and reverse transcription, the cDNA was analysed for relative gene expression using real-time PCR. Gene expression patterns were compared on a patient-matched basis.

Results: Histological analysis showed that the advanced OA cartilage differed from the minimal cartilage with regard to cloning (p< 0.001), fibrillation (p< 0.001), and proteoglycan depletion (p< 0.001). There was no difference in overall cellularity. The advanced OA cartilage had significantly less proteoglycan content than the minimal tissue, with no difference found in hydroxyproline content. The following changes were observed in the relative expression level of specific genes: 1) the steady state level of osteopontin mRNA showed an overall 3.5-fold increase in advanced OA cartilage compared to minimal (p< 0.01); 2) The mRNA coding for aggre-can was down-regulated in advanced disease tissue to less than 50% the level found in minimal tissue in nine out of 11 patients; 3) the expression of mRNA coding for link protein was also significantly decreased in advanced OA cartilage compared to minimal in nine out of 11 patients; and 4) the mRNA level coding for collagen II did not show an obvious pattern of expression in the minimal versus advanced cartilage. The expression of mRNA coding for MMPs was variable with regard to disease state with the majority of patients showing decreased MMP3, MMP9, and MMP13 mRNA expression in advanced OA tissue compared to minimal.

Conclusions: This study clearly demonstrates that patient-matched minimal and advanced OA cartilage show significant differences in cell and matrix characteristics. In addition, differential patterns of gene expression are observed in this model that may relate to the pathogenic mechanism operating during progression of OA.

Purpose: The purpose of this study was to examine the measurement properties of four commonly used disability measures. We hypothesized that all measures would have a high (0.8 or > 0.8) internal consistency and ability to discriminate between men and women’s level of disability. A moderate convergent validity (0.5 to 1.00).

Method: This was a prospective longitudinal study of patients with advanced primary osteoarthritis of glenohumeral joint who underwent a Total Shoulder Arthroplasty (TSA). Four measures [Western Ontario Osteoarthritis Shoulder (WOOS) Index, the American Shoulder and Elbow Surgeon’s (ASES) assessment, Constant-Murley Score (CMS), and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH)] were completed 2–3 weeks before surgery and at 6 months after surgery. The measurement properties were examined in:

internal consistency as a measure of reliability,

Analysis involved calculating Cronbach Coefficient Alpha to measure internal consistency. Convergent validity was examined by the Pearson correlation coefficient. Analysis of Variance examined the extent of known group validity. The Standardized Response Mean (SRM) was used to measure the relative sensitivity to change.

Results: Seventy patients (mean age: 65, range: 35–86, 44 females, 26 males) participated in the study. The Cronbach Coefficient Alpha was high at 0.91, 0.86, and 0.83 for WOOS, ASES, and QuickDASH respectively. Cross-sectional convergent validity was moderate with correlations varying from 0.54 to 0.79. Longitudinal convergent validity ranged from 0.58 to 0.88. All measures were able to discriminate between men and women at p< 0.05 with Cohen’s d of 1.07, 0.85, 0.82, and 0.55 for QuickDASH, CMS, WOOS, and ASES respectively. The SRM was 2.41, 2.17, 1.88, and 1.63 for WOOS, CMS, ASES and QuickDASH respectively.

Conclusion: All four disability measures were valid and reliable in candidates for TSA. The WOOS, a disease-specific outcome demonstrated a higher reliability and sensitivity to change than other measures. QuickDASH had a better ability to differentiate between men and women. Clinicians may not gain additional information by administrating multiple similar outcome measures. Researchers will decrease their chance of declaring a statistical significance by choosing one primary outcome measure.

Although periacetabular osteotomies are widely used for the treatment of symptomatic acetabular dysplasia, the surgical outcomes after long term follow-up are still limited. Thus, we assessed hip survival and patient-reported outcomes (PROMs) at 20 years after the transposition osteotomy of acetabulum (TOA). Among 260 hips in 238 patients treated with TOA, 172 hips in 160 patients were evaluated at average 20.8 years, excluding patients who died or lost to follow-up. Kaplan-Meier analysis was used to assess survivorship with an end-point of THA. PROMs were evaluated using the VAS satisfaction, VAS pain, Oxford hip score (OHS), and Forgotten joint score (FJS). The thresholds of favorable outcomes of FJS and OHS were obtained using the receiver-operating characteristic curve with VAS satisfaction ≥ 50 and VAS pain < 20 as anchors. Thirty-three hips (19.2%) underwent THA at average 13.3 years after TOA. Kaplan-Meier analysis revealed hip survival rate at 20 years was 79.7%. Multivariate analysis showed the preoperative Tönnis grade significantly influenced hip survival. Survival rates with Tönnis grade 0, grade 1, and grade 2 were 93.3%, 86.7%, and 54.8% at 20 years, respectively. More than 60% of the patients showed favorable PROMs (VAS satisfaction ≥ 50, VAS pain < 20, OHS ≥ 42, FJS ≥ 51). Advanced Tönnis grade at the latest follow-up and higher BMI were significantly associated with unfavorable OHS, but not with other PROMs. This study demonstrated the durability of TOA for hips with Tönnis grade 0–1 and favorable satisfaction in majority of the patients at 20 years after surgery. Current presence of advanced osteoarthritis is associated with the lower hip function (OHS), but not necessarily associated with subjective pain and satisfaction. Higher BMI also showed a negative impact on postoperative function

Tibial cut is a crucial step in ensuring adequate and appropriate proximal tibial resection for mechanical orientation and axis in total knee replacement. We evolved the concept and technique of Condylar Differential for planned tibial cuts in conventional total knee replacement, which accounts for individual variations and reflects individual mechanical orientation and alignment. We used Condylar Differential in 37 consecutive total knee replacements including valgus knees and severe advanced osteoarthritis. First a vertical line is drawn on digital weight bearing anteroposterior radiograph for mechanical axis of tibia. Then a horizontal line is drawn across and perpendicular to the mechanical axis. The distances between the horizontal line and the lowest reproducible points of articular surfaces of medial and lateral tibial condyles respectively are measured. The difference between two measurements obviously represents Condylar Differential. Condylar Differential, adjusted to the nearest millimetre, is maintained in executing tibial cuts, successively if necessary. Condylar Differential measurement showed a very wide variation, ranging from 8–6 (2 mm) to 10-0 (10 mm). We found that prior measurement of Condylar Differential is a simple, consistent and effective estimate and individualises the tibial cut for optimal templating of tibia. We encountered no problems, adopting this technique, in our series. Condylar Differential contributes to optimal individualised tibial cut in conventional total knee replacement and is a useful alternative to computer navigated option with comparable accuracy in this respect. While we used the technique in digitised radiographs, this technique can also be applied to plain films, allowing for magnification

Transposition osteotomy of the acetabulum (TOA) was the first periacetabular osteotomy for the osteoarthritis hips due to acetabular dysplasia, in which the acetabulum was transposed with articular cartilage. TOA improves coverage of the femoral head to restore congruity and stability, and also prevent further osteoarthritis deterioration and induce regeneration of the joint. Many good clinical outcomes have been reported for such periacetabular osteotomies for osteoarthritis of the hips at an early stage. In contrast, the clinical outcome is controversial for those hips at an advanced stage, in which the joint space has partly disappeared. The purpose of this study was to investigate whether TOA is an appropriate option for treatment of osteoarthritis of the hips at the advanced stage by comparing with matched control hips at the early stage. Between 1998 and 2001, TOA was performed in 104 hips of 98 patients. Sixteen of 17 hips (94%) with osteoarthritis at the advanced stage were examined and compared with 37 matched control hips at the early stage. The mean age at the operation was 48(38–56) and the mean follow-up period was 88 (65–107) months. TOA corrected the acetabular dysplasia and significantly improved containment of the femoral head. No hips had secondary operations including THA. Clinical scores were also significantly improved in both of the groups. In the advanced osteoarthritis cases, there was a tendency for abduction congruity before transposition osteotomy of the acetabulum to reflect the clinical outcome. TOA is a promising treatment option for the advanced osteoarthritis of the hips as well as for those patients at the early stage when preoperative radiographs show good congruity or containment of the joint

The primary aim of this study was to identify the rate of osteoarthritis in scaphoid fracture non-union. We also aimed to investigate whether the incidence of osteoarthritis correlates with the duration of non-union(interval), and to identify the variables that influence the outcome. We retrospectively reviewed 273 scaphoid fracture non-union presented between 2007 and 2016. Data included patient demographics, interval, fracture morphology, grade of osteoarthritis (Kellgren-Lawrence) and scaphoid non-union advanced collapse (SNAC), and overall health-related quality of life. Patients were divided into two groups (SNAC and Non-SNAC). Group differences were analysed using Mann-Whitney U test and association with Pearson's correlations. A two-sided p-value of <0.05 was considered significant. The scaphoid fracture non-union were confirmed on CT scans (n=243) and plain radiographs (n=35). The subjects were 32 females and 260 males with the mean age of 33.8 years (SD, 13.2). The average interval was 3.1 years (range, 0–45 years). Osteoarthritis occurred in 58% (n=161) of non-unions, and 42% (n=117) had no osteoarthritis. In overall, 38.5% (n=107) had SNAC-1, 9% (n=25) with SNAC-2, and 10.4% (n=29) presented with SNAC-3. The mean interval in the non-SNAC group was 1.2 years, and in SNAC 1,2, and 3 were 2.6, 6.8, and 11.1 years, respectively. The average summary index in SNAC and non- SNAC groups was 0.803 and 0.819, respectively. Our results also showed a significant correlation between advanced osteoarthritis and proximal fracture non-unions(P<0.05). We concluded that there is no clear correlation between the interval and the progression of osteoarthritis. SNAC was more likely to occur in fractures aged 2 years or older

Introduction. Total hip arthroplasty (THA) is an effective surgery for the treatment of advanced osteoarthritis but increasing numbers of these procedures are having a significant impact on healthcare budgets. One route to mitigate the increasing costs is outpatient THA, discharging patients on the same day as their surgery. The purpose of this study was to determine the cost of outpatient THA compared to standard overnight stay in hospital. Methods. This was a prospective-randomized controlled trial for patients undergoing primary THA through a direct anterior approach. Participants were randomized to be discharged on the same day as surgery, as outpatients, or on day one post-surgery, as inpatients, using a Zelen consent model. Adverse events were assessed, and participants completed self-reported cost questionnaires at two-, six- and 12-weeks post-surgery, and the WOMAC preoperatively and at 12-weeks post-surgery. We performed a cost analysis from health care payer (HCP) and societal perspectives. Results. 106 patients were enrolled in this study, with 50 randomized to outpatient and 56 randomized to inpatient THA. Seven patients from the outpatient group and five patients from the inpatient group crossed-over. Adverse event rate was similar between the groups with seven events in four participants in the inpatient group and three events in two participants in the outpatient group. WOMAC scores were not significantly different between the groups (p=0.12). From both a HCP and societal perspective, inpatient THA was more costly than outpatient THA. The cost difference was $3,353.15 for HCP (p<0.0001) and $3,703.30 for societal (p=0.003) in favour of outpatient THA. Conclusion. Our results suggest that outpatient THA is a cost-saving procedure when compared to inpatient THA from both HCP and societal perspectives. We will continue recruitment to investigate whether these results hold true in a larger sample as well as assess for cost-effectiveness, patient safety and satisfaction. Acknowledgements. This study was supported by the Opportunities Fund of the Academic Health Sciences Centre Alternative Funding Plan of the Academic Medical Organization of Southwestern Ontario (AMOSO). We also received funding from the PSI Foundation. For any tables or figures, please contact the authors directly

Background. Mechanics and kinematics of the knee following total knee replacement are related to the mechanics and kinematics of the normal knee. Restoration of neutral alignment is an important factor affecting the long-term results of total knee replacement. Tibial cut is a vital and crucial step in ensuring adequate and appropriate proximal tibial resection, which is essential for mechanical orientation and axis in total knee replacement. Tibial cut must be individually reliable, reproducible, consistent and an accurate predictor of individual anatomical measurements. Conventional tibial cuts of tibia with fixed measurements cannot account for individual variations. While computer navigated total knee replacement serves as a medium to achieve this objective, the technology is not universally applicable for differing reasons. Therefore we evolved the concept and technique of Condylar Differential for planned tibial cuts in conventional total knee replacement, which accounts for individual variations and reflects the individual mechanical orientation and alignment. Methods. We used the Condylar Differential in 37 consecutive total knee replacements. We also applied the technique in valgus knees and severe advanced osteoarthritis. First a vertical line is drawn on the digital weight bearing anteroposterior radiograph for mechanical axis of tibia. Then a horizontal line is drawn across and perpendicular to the mechanical axis of tibia. The distances between the horizontal line and the lowest reproducible points of the articular surfaces of the medial and lateral tibial condyles respectively are measured. The difference between the two measurements obviously represents the Condylar Differential. Condylar Differential, adjusted to the nearest millimeter, is maintained in executing the tibial cuts, if necessary successive cuts. Results. Condylar Differential measurement showed a very wide variation, ranging from 8–6 (2 mm) to 10-0 (10 mm). We found that prior measurement of Condylar Differential is a simple, consistent and effective estimate and individualizes the tibial cut for optimal templating of tibia in total knee replacement. We encountered no problems, adopting this technique, in our consecutive series of total knee replacements. Conclusions. Condylar Differential contributes to optimal individualized tibial cut in conventional total knee replacement and is a useful alternative to computer navigated option with comparable accuracy in this respect. While we used the technique of Condylar Differential in digitized radiographs, this technique can also be applied to plain films, allowing for the magnification

Introduction. Total knee arthroplasty is a highly effective procedure to improve the quality of life in patients with advanced osteoarthritis. The number of these procedures are expected to grow 174% by 2030. This growth rate is expected to economically strain the health care system. A potential solution to alleviate this problem is the utilization of single use instruments (SUI). Potential advantages of SUI include: improved operating room efficiencies, decreased costs associated with traditional instrument management (sterile processing, shipping), and decreased infection risk. The present study examines the clinical results of SUI compared to standard instrumentation. Furthermore, economic modeling is performed to examine the cost savings that is potentially realized with their use. Materials and Methods. 51 patients receiving a TKA with use of SUI were prospectively compared to 49 patients utilizing standard instrumentation. Knee Society Scores and Radiographic alignment will be evaluated. Adverse events will be recorded. Economic modeling of SUI will be performed in 4 different areas: 1. Decreased infection burden; 2. Operating room logistics; 3. Sterile processing savings; and 4. Instrument logistical savings. Results. The average Pre-operative KSS (Objective/Functional) scores were 48.7/41.6 for the SIU patients compared to 50.2/38.7 for the standard instrumentation patients. Post-operative improvements measured 84.0/72.8 and 83.9/76.4 for the 2 groups respectively. The Pre-operative Hip-Knee-Ankle Angle was 176.2 and 177.0 for the 2 groups. The SUI HKA improved to 179.3 while the standard improved to 178.9. There were no statistical differences between the 2 groups. Furthermore, there were no cases of subsidence, migration, loosening, or infection in either group. There were no SUI procedure abandonments. Economic analysis revealed a decreased risk of Infection burden of $28.08/case. Operating room efficiencies include reduced set-up/take-down time and case efficiency savings/case. This averages $348.14/case. Instrument sterilization savings occur by bypassing the central sterile-processing department completely and models to $700/case. Finally, instrument logistics savings include time and money spent organizing/turning over/shipping instrument sets for cases. This estimate is $112.88/case for a total economic value of $1, 189.10/case. Discussion. In summary, the present study confirms that SUI provides similar clinical and radiographic results to standard instrumentation for TKA. Furthermore, SUI offers significant cost savings/case via potential benefits of reduced risk of infection, increased operating room productivity, and significant tray sterilization and loaner instrumentation cost savings

Introduction. The obesity epidemic is a growing problem and must be considered with the projected increased demand for total hip arthroplasty (THA). Previous studies have reported increased complication rates after THA in the obese population, which has led to hesitation in offering surgery to this population. Moreover, some insurers are denying coverage for morbidly obese patients. While many consider obesity a “modifiable” risk factor, very few patients with advanced osteoarthritis have successfully lost substantial weight. The experience of centers that utilize systematic preoperative risk stratification tools and standardized postoperative total joint pathways may be underrepresented in prior studies. The aim of this study is to describe one surgeon's experience performing THA in morbidly and super-obese patient populations using an institutional preoperative Risk Stratification Tool (RST) and total joints pathway. Methods. We conducted a retrospective review of patients undergoing primary THA between May 2014 and December 2017 performed by a single surgeon at a tertiary care referral center. All patients were assessed preoperatively using an institutional RST and had a minimum of 90-day postoperative follow up. Patients were stratified by body mass index (BMI, kg/m. 2. ): non-obese (BMI < 30), obese (30–34), severely obese (35–39), morbidly obese (40–44), and super-obese (≥ 45). Primary outcomes were inpatient and 90-day complications. Continuous and binary parameters were analyzed by Kruskal-Wallis and Fisher exact tests. Logistic regression was additionally utilized to evaluate outcomes by BMI cohort. Results. A consecutive series of 368 patients met inclusion criteria across all BMI cohorts. There was significant variation with respect to age (P=0.001), BMI (P<0.001), diabetes (P=0.008), ASA class (P<0.001), and anesthesia type (P=0.003) (Table 1). Variation among BMI cohorts was also identified for several operative and postoperative parameters, including longer operative and in-room time and greater length of stay (P<0.001) (Table 2). Compared to non-obese patients, super-obese patients had 20.1 greater odds of return to OR within 90 days for superficial surgical site infection (SSI) or prolonged round drainage (P=0.008) (Table 3). Notably, morbidly and super-obese patients were not at significantly increased risk for inpatient intensive care unit (ICU) transfer, blood transfusion, 90-day emergency room visit, or 90-day readmission compared to their non-obese counterparts. For patients in whom 1-year follow-up was available, these differences between BMI cohorts remained insignificant. Conclusions. Patients with BMI>40 are more likely than non-obese patients to have increased postoperative rehabilitation needs but are not at increased risk for in-hospital complications. Super-obese patients have greater risk of superficial SSI or prolonged wound drainage than non-obese patients but are not at increased risk for revision or deep infection in any cohort. Use of a preoperative RST may help to mitigate postoperative complications and readmissions previously associated with morbid and super-obesity. We conclude that THA can be safely performed in super-obese patients and therefore care should not be denied to this population. Summary sentence. Total hip arthroplasty (THA) can be safely performed in morbidly and super-obese patients with the use of a preoperative risk stratification tool (RST) and total joints pathway. For any tables or figures, please contact the authors directly

Introduction. Total knee replacement (TKR) is an established and effective surgical procedure in case of advanced osteoarthritis. However, the rate of satisfied patients amounts only to about 75 %. One common cause for unsatisfied patients is the anterior knee pain, which is partially caused by an increase in patellofemoral contact force and abnormal patellar kinematics. Since the malpositioning of the tibial and the femoral component affects the interplay in the patellofemoral joint and therefore contributes to anterior knee pain, we conducted a computational study on a cruciate-retaining (CR) TKR and analysed the effect of isolated femoral and tibial component malalignments on patellofemoral dynamics during a squat motion. Methods. To analyse different implant configurations, a musculoskeletal multibody model was implemented in the software Simpack V9.7 (Simpack AG, Gilching, Germany) from the SimTK data set (Fregly et al.). The musculoskeletal model comprised relevant ligaments with nonlinear force-strain relation according to Wismans and Hill-type muscles spanning the lower extremity. The experimental data were obtained from one male subject, who received an instrumented CR TKR. Muscle forces were calculated using a variant of the computed muscle control algorithm. To enable roll-glide kinematics, both tibio- and patellofemoral joint compartments were modelled with six degrees of freedom by implementing a polygon-contact-model representing the detailed implant surfaces. Tibiofemoral contact forces were predicted and validated using data from experimental squat trials (SimTK). The validated simulation model has been used as reference configuration corresponding to the optimal surgical technique. In the following, implant configurations, i.e. numerous combinations of relative femoral and tibial component alignment were analysed: malposition of the femoral/tibial component in mediolateral (±3 mm) and anterior-posterior (±3 mm) direction. Results. Mediolateral translation/malposition of the tibial component did not show high influence on the maximal patellofemoral contact force. Regarding the mediolateral translation of the femoral component, similar tendencies were observed. However, lateralisation of the femoral component (3 mm) clearly increased the lateral patella shift and medialisation of the tibial component (3 mm) led to a slightly increased lateral patella shift. Compared to the reference model, pronounced posterior translation of the tibial and femoral component resulted in a lower patellofemoral contact force, further increasing with higher anterior translation of the components. The translation of the tibial component showed smaller influence on the patellofemoral contact force than the translation of the femoral component. Discussion. In our present study, the mediolateral malposition of the femoral and tibial component showed no major impact on patellofemoral contact force and contribution to anterior knee pain in patients with CR TKR. However, the influence of implant component positioning in anterior-posterior direction on patellofemoral contact force is evident, especially for the femoral component. Our generated musculoskeletal model can contribute to computer-assisted preclinical testing of TKR and may support clinical decision-making in preoperative planning

It is unusual to require the use of a total knee implant with more constraint than a posterior-stabilised post in primary knee arthroplasty. The most common indication is a knee with a severe deformity, usually fixed valgus with an incompetent medial collateral ligament, and an inability to correctly balance the knee in both flexion and extension. The pre-operative deformity is usually greater than 15–20 degrees fixed valgus and may be associated with a severe flexion contracture. This is usually seen in an elderly female patient with advanced osteoarthritis. Those pre-operative diagnoses more likely to require a constrained design include advanced rheumatoid arthritis, true neuropathic joint, and the “Charcot-like” joint due to bone loss or crystalline arthritis. Rarely, patients with periarticular knee Paget's disease of bone may require more constraint following correction of a severe deformity through the knee joint. Beware those patients with a staple or screw at the medial epicondyle or those with severe heterotopic ossification at the medial joint line, as this may signify a serious prior injury to the medial collateral ligament. Finally, there is a possibility of inadvertent division of the medial collateral ligament intra-operatively. Although this situation may be treated with suture repair and bracing, my choice is to switch to more constraint and early unbraced motion. There are over 20 designs of varus-valgus constrained components, with a variety of tibial post designs with specific rotary and angular biomechanics, and many have the option of adding modular stems. Our experience with constrained, non-linked designs has been favorable with both the use of nonmodular and modular stem extensions. Longer-term survival analysis has shown a 96% survival at 10 years with these constrained components. However, the older designs frequently required a lateral retinacular release for proper patella tracking, and there were patella complications (fracture and osteonecrosis) in 16%. With a more modern design, over the past 12 years, the need for a lateral retinacular release and patella complications have been notably decreased. Varus-valgus constrained components have a small but important role in primary total knee arthroplasty for patients with severe deformity or an incompetent medial collateral ligament

Total knee arthroplasty has been the main treatment method among advanced osteoarthritis (OA) patients. The main post-operative evaluation considers the level of pain, stability and range of motion (ROM). The knee flexion level is one of the most important categories in the total knee arthroplasty patient's satisfaction in Asian countries due to consistent habits of floor-sitting, squating, kneeling and cross legged sitting. In this study, we discovered that the posterior capsular release enabled the further flexion angles by 14 degrees compared to the average ROM without posterior release group. Our objective was to increase the ROM using the conventional total knee arthroplasty by the posterior capsular release. Posterior capsular release is being used in order to manage the flexion contraction. Although the high flexion method extends the contact area during flexion by extending the posterior condyle by 2mm, the main problem has been the early femoral loosening. We searched for the method to get the deep knee flexion with the conventional knee prosthesis. 122 OA patients with less than preoperative 130 flexion that underwent conventional TKAs using Nexgen from January, 2014 to September, 2016 were reviewed. Posterior femoral osteophytes were removed as much as possible, but 74 cases were performed posterior capsular release, while 48 cases were not performed. After checking postoperative ROM after 6 months of operation, we compared 74 knees with a posterior capsular release and 48 knees without posterior capsular release. As a result, the average ROM in the posterior capsular release group was 132 degrees, but the average ROM without posterior release group is 118 degrees. No postoperative hyperextension was found when the adequate size of polyethylene (PE) thickness was utilized. Hence, the conventional TKA with a posterior capsular release showed satisfactory clinical outcomes in the deep knee flexion of Asians

Aims

This study compared patient-reported outcomes of three total knee arthroplasty (TKA) designs from one manufacturer: one cruciate-retaining (CR) design, and two cruciate-sacrificing designs, anterior-stabilized (AS) and posterior-stabilized (PS).

Introduction. Most of the algorithm available today to balance varus knee is based on a surgeon's hands-on experience without full understanding of pathological anatomy of varus knee. The high-resolution MRI allows us to recognize the anatomical details of the posteromedial corner and the changes of the soft tissue associated with the osteoarthritis and varus deformity. We have in this study, reviewed 60 cases of severe varus knee scheduled for TKR and compared it to normal MRI and those MRI were evaluated and read by a musculoskeletal radiologist. We have documented clearly the changes that happens in soft tissue, leading to tight medial compartment. We will also show multiple short intra-operative video confirming that MRI findings. Material & method. We have retrospectively reviewed the MRI on 60 patients with advanced osteoarthritis varus knee. We also reviewed 20 MRI for a normal knee matched for age. We evaluated the posteromedial complex and MCL in sagittal PD-weighted VISTA to check the alignment of the MCL and posteromedial complex and the associate MCL bowing and deformity that could happen in osteoarthritis knee. We have measured the thickness of the posteromedial complex and the posterior medial bowing of the superficial MCL and the involvement of the posterior oblique ligament in those patients. To measure the posterior bowing of the MCL, a line was drawn through the posterior aspect of both menisci and we measured the distance between the posterior edge of MCL to that line in actual image. To measure the thickness of the posteromedial complex, we measured it at two areas in the posterior medial corner posteriorly at the level of the medial meniscus. Measuring the medial bowing of the MCL was done by a line drawn through the medial edge of the femoral condyle and the tibial condyle at the level of the medial meniscus to the inner aspect of the MCL. The normal distance between the posterior aspects of the MCL to the posterior meniscus line was approximately measured 2 cm. in average. Results. We were able to recognize and measure the medial deviation of MCL in all arthritic knees due to the deformity and the effect of the medial margin osteophyte and medial extrusion of the meniscus. Thickening of posteromedial complex was recognized in the majority of the cases with prominent thickening seen in 50/60 knees with average thickness measuring approximately 1.2 cm due to the synovial thickening, adhesions, granulation tissue, degenerated medial meniscus, and involvement of the posterior oblique ligament and the capsular branch of the semimembranosus tendon, as well as the oblique popliteal ligament. The involvement of posterior oblique ligament were seen in majority of the cases. In 55 cases we have showed a heterogeneous appearance of the ligament and loss of normal signal within the postero medial complex and we have documented that the oblique ligament will cause the posterior bowing of the MCL. The medial bowing of the MCL is also correlated to the severity of the varus deformity with an average distance to the normal medial line of the medial meniscus measuring approximately 1.1 cm. Discussion. Our study shows that the changes affecting the superficial MCL is likely to be secondary to the obvious changes involving the posteromedial complex and to the marginal osteophyte as well as the extrusion of the medial meniscus. Also, we have confirmed that there are deforming structures such as the oblique ligament with adhesion and thickening with all the posterior medial complex. Those changes clearly caused the posterior bowing to the superficial MCL without an actual shortening of the ligament. The scarring tissue in the posteromedial corner and the adhesion is acting as a soft phyte tensioning and deforming the ligament and the posterior capsule. The oblique ligament act as a deforming forces forcing the superficial MCL to bow posteriorly. The lengths of the superficial MCL stayed the same. Conclusion. The conventional wisdom of releasing the distal attachment of the superficial medial MCL to balance knee has to be a challenge based on our MRI finding. Releasing the superficial MCL can sometimes lead to a major instability of the knee requiring a more constrained implant. Our MRI assessment clearly showed that the Superficial MCL is deformed because of posterior bowing and medial bowing and considerable thickening of the posteromedial corner, as well as the accompanying osteophyte. We believe that clearing the superficial MCL and excising those thickened scar tissue in the posterior medial corner will enable us to balance the knee without creating instability Conclusion: The conventional wisdom of releasing the distal attachment of the superficial medial MCL to balance knee has to be a challenge based on our MRI finding. Releasing the superficial MCL can sometimes lead to a major instability of the knee requiring a more constrained implant. Our MRI assessment clearly showed that the Superficial MCL is deformed because of posterior bowing and medial bowing and considerable thickening of the posteromedial corner, as well as the accompanying osteophyte. We believe that clearing the superficial MCL and excising those thickened scar tissue in the posterior medial corner will enable us to balance the knee without creating instability