Knee Society Clinical Rating System Research Articles

Minimum 15-Year Survival of a Biconvex Inlay Patellar Component in Primary Total Knee Arthroplasty: An Analysis of 2,530 Total Knee Arthroplasties From a Single Institution

BackgroundRoutine patellar resurfacing during primary total knee arthroplasty (TKA) remains controversial. To our knowledge, there are no studies reporting the long-term performance of a cemented biconvex all-polyethylene inlay component implanted at the time of primary TKA. The purpose of this study was to examine the 15-year survivorship and long-term clinical outcomes of this biconvex inlay patella used at our institution. MethodsWe retrospectively reviewed our prospectively collected institutional database and identified 2,530 patients who underwent cemented TKA with a single prosthetic design (from 1996 to 2007) where the patella was resurfaced using this cemented biconvex inlay patella. The mean age at surgery was 68 years (range, 29 to 93). The mean body mass index was 33.0 (range, 16.4 to 76.3), with 61.9% women. At the time of analysis, the mean time from surgery was 20.4 years (range, 15 to 26). We used Kaplan–Meier analysis to calculate survivorship at 15 years. We analyzed clinical outcomes using 3 patient-reported outcome measures collected prospectively. ResultsThe 15-year survivorship with revision surgery for all causes as the end point was 97.1% (95% confidence interval 96.1 to 98.1%). The 15-year survivorship with revision surgery for a patella-related complication as the end point was 99.7% (95% confidence interval 99.4 to 1.0). At the final follow-up, patients showed significant improvement in scores for the Knee Society Clinical Rating System (P < .001), Western Ontario and McMaster University Osteoarthritis Index (P < .001), and Veterans Rand 12-Item Health Survey physical component (P < .001). ConclusionsRoutine patellar resurfacing using a biconvex inlay patellar component has excellent survivorship and a low rate of complications at 15 years post-TKA.

How to Choose the Appropriate Posterior Slope Angle Can Lead to Good Knee Joint Function Recovery in Total Knee Arthroplasty?

In this study, we aim to examine the effects of osteotomy under varying posterior slope angles on knee joint function recovery following knee arthroplasty. We conducted a retrospective analysis from September 2015 to September 2018 on 240 patients who underwent knee arthroplasty three years previously. The study participants were categorized based on changes in the angle of the posterior slope before and after surgery: Group 1, > 5°; Group 2, 3°-5°; Group 3, 0°-3°; Group 4, -3°-0°; Group 5, < -3°. All participants were affected with knee osteoarthritis. The Knee Society Clinical Rating System (KSS) knee function score, Western Ontario and McMaster Universities Arthritis Index (WOMAC) knee function score, Visual Analogue Scale (VAS) pain score, and postoperative complications were measured 3 years after surgery. The level of pain experienced by the patients decreased significantly than before, with pain scores ranging from 1.0-3.0, and there was a statistical difference between groups (H = 93.400, P <0.001). The KSS score increased, with group 5 having the lowest median score of 78.0 and group 2 having the highest median score of 97.0, and there was a statistical difference between groups (H = 164.460, P < 0.001). The WOMAC score was reduced, with the median score being 24.0, 11.0, 14.0, 20.0, and 26.0, in the five groups, respectively. Group 5 had the highest score, while Group 2 had the lowest score, and there was a statistically significant difference between groups (H = 164.223, P < 0.001). No symptoms such as periprosthetic femoral fracture, prosthetic loosening, or pad wear were detected in patients postoperatively. Osteotomy at various posterior slope angles in total knee arthroplasty impacts postoperative knee function rehabilitation. An excessive increase or decrease in angle can have an impact on the postoperative recovery of knee function.

A Gel-Based Proteomic Analysis Reveals Synovial α-Enolase and Fibrinogen β-Chain Dysregulation in Knee Osteoarthritis: A Controlled Trial.

The identification of synovial fluid (SF) biomarkers that could anticipate the diagnosis of osteoarthritis (OA) is gaining increasing importance in orthopaedic clinical practice. This controlled trial aims to assess the differences between the SF proteome of patients affected by severe OA undergoing Total Knee Replacement (TKR) compared to control subjects (i.e., subjects younger than 35, undergoing knee arthroscopy for acute meniscus injury). The synovial samples were collected from patients with Kellgren Lawrence grade 3 and 4 knee osteoarthritis undergoing THR (study group) and young patients with meniscal tears and no OA signs undergoing arthroscopic surgery (control group). The samples were processed and analyzed following the protocol defined in our previous study. All of the patients underwent clinical evaluation using the International Knee Documentation Committee (IKDC) subjective knee evaluation (main outcome), Knee Society Clinical Rating System (KSS), Knee injury and Osteoarthritis Outcome Score (KOOS), and Visual Analogue Scale (VAS) for pain. The drugs' assumptions and comorbidities were recorded. All patients underwent preoperative serial blood tests, including complete blood count and C-Reactive Protein (CRP). The synovial samples' analysis showed a significantly different fibrinogen beta chain (FBG) and alpha-enolase 1 (ENO1) concentration in OA compared to the control samples. A significant correlation between clinical scores, FBG, and ENO1 concentration was observed in osteoarthritic patients. Synovial fluid FBG and ENO1 concentrations are significantly different in patients affected by knee OA compared with non-OA subjects.

Does the use of 3D-printed cones give a chance to postpone the use of megaprostheses in patients with large bone defects in the knee joint?

Revision procedures and the resulting bone loss are a big challenge for orthopedic surgeons. Therefore, we checked what functional outcomes that 3D-printed cone augments can offer to patients with bone defects (Anderson Orthopedic Research Institute [AORI] classification type 2B and 3) in the knee and whether the use of cones can delay the necessity to use a megaprotheses. Data from 64 patients (M = 22; W = 42) who underwent total knee arthroplasty (TKA) revision were included in the analysis. The Knee Society Clinical Rating System (KSS) and the range of motion in the knee joint were used for the functional assessment. The mean follow-up was 28 months (range: 18–44 months). The survival rate for aseptic loosening at follow-up was 100%. Infection occurred in two (3.1%) patients. The mean KSS score increased from 12.75 points preoperatively to 66.56 postoperatively (p < 0.001). The mean range of motion in the knee changed from 61.15° preoperatively to 115.93° postoperatively (p < 0.001). 3D-printed cone augments seem to be a good solution for patients requiring a TKA revision procedure. When used in patients with bone defects classified as 2B and 3 (AORI), they can be a good alternative, delaying the need for megaprotheses.

Logistic Regression and Machine Learning Models Cannot Discriminate Between Satisfied and Dissatisfied Total Knee Arthroplasty Patients

Approximately 20% of total knee arthroplasty (TKA) patients are found to be dissatisfied or unsure of their satisfaction at 1-year post-surgery. This study attempted to predict 1-year post-surgery dissatisfied/unsure TKA patients with pre-surgery and surgical variables using logistic regression and machine learning methods. A retrospective analysis of patients who underwent primary TKA for osteoarthritis between 2012 and 2016 at a single institution was completed. Patients were split into satisfied and dissatisfied/unsure groups. Potential predictor variables included the following: demographic information, patella re-surfaced, posterior collateral ligament sacrificed, and subscales from the Knee Society Knee Scoring System, the Knee Society Clinical Rating System, the Western Ontario and McMaster Universities Osteoarthritis Index, and the 12-Item Short Form Health Survey version 2. Logistic regression and 6 different machine learning methods were used to create prediction models. Model performance was evaluated using discrimination (AUC [area under the receiver operating characteristic curve]) and calibration (Brier score, Cox intercept, and Cox slope) metrics. There were 1432 eligible patients included in the analysis, 313 were considered to be dissatisfied/unsure. When evaluating discrimination, the logistic regression (AUC= 0.736) and extreme gradient boosted tree (AUC= 0.713) models performed best. When evaluating calibration, the logistic regression (Brier score= 0.141, Cox intercept= 0.241, and Cox slope= 1.31) and gradient boosted tree (Brier score= 0.149, Cox intercept= 0.054, and Cox slope= 1.158) models performed best. The models developed in this study do not perform well enough as discriminatory tools to be used in a clinical setting. Further work needs to be done to improve the performance of pre-surgery TKA dissatisfaction prediction models.

Treatment of knee osteoarthritis with intra-articular injection of allogeneic adipose-derived stem cells (ADSCs) ELIXCYTE\xae: a phase I/II, randomized, active-control, single-blind, multiple-center clinical trial

ObjectiveTo evaluate the safety and efficacy of intra-articular (IA) injection of allogeneic adipose-derived stem cells (ADSCs) ELIXCYTE® for knee osteoarthritis.MethodsThis was a patient-blind, randomized, active-control trial consisted of 4 arms including hyaluronic acid (HA) control and 3 ELIXCYTE® doses. A total of 64 subjects were screened, and 57 subjects were randomized. The primary endpoints included the changes from baseline to post-treatment visit of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score at Week 24 and the incidence of adverse events (AEs) and serious adverse events (SAEs).ResultsNo ELIXCYTE®-related serious adverse events were reported during 96 weeks of follow-up and no suspected unexpected serious adverse reaction (SUSAR) or death was reported. The changes of the primary endpoint, WOMAC pain score at Week 24, showed significant differences in all ELIXCYTE® groups, as well as in HA groups between post-treatment visit and baseline. The ELIXCYTE® groups revealed significant decreases at Week 4 compared to HA group in WOMAC total scores, stiffness scores, functional limitation scores suggested the potential of ELIXCYTE® in earlier onset compared to those from HA. The significant differences of visual analog scale (VAS) pain score and Knee Society Clinical Rating System (KSCRS) functional activities score at Week 48 after ELIXCYTE® administration suggested the potential of ELIXCYTE® in the longer duration of the effectiveness compared to HA group.ConclusionsELIXCYTE® for knee osteoarthritis treatment was effective, safe, and well-tolerated. The efficacy results were showed that ELIXCYTE® conferred the earlier onset of reductions in pain scores and improvements in functional scores than HA group.Trial registration: ClinicalTrials.gov Identifier: NCT02784964. Registered 16 May, 2016—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02784964

Functional results and survivorship after medial unicompartmental knee arthroplasty: a single center experience from Saudi Arabia.

BACKGROUND: Isolated involvement of the medial compartment of the knee in degenerative disease is encountered in about 25% of patients with gonarthrosis. We aim to show that in a well-selected group of such patients, medial unicompartmental knee arthroplasty (UKA) is a good option.OBJECTIVES: Review the functional outcomes of patients undergoing UKA and determine the long-term survivorship of the implants and complications of the procedure.DESIGN: Analytical retrospective chart review.SETTING: Academic tertiary care medical center and tertiary care private hospital in the western region of Saudi Arabia.PATIENTS AND METHODS: We selected patients who underwent medial UKAs by the same surgeon between December 1988 and December 2009. The life table approach and the Kaplan-Meier statistical method were used to estimate the survival rate (5–30 years) with revision as the endpoint. Functional outcome scores were determined according to the Knee Society Clinical Rating System.MAIN OUTCOME MEASURES: Change in performance scores for pain, walking, and range of movement. Survivorship of the implants with removal of the implant as the endpoint; post-operative complications.SAMPLE SIZE: 218 implants on 142 patients.RESULTS: The survival rate for UKA was 94.7% at 10 years (95% CI 0.906–0.970), 80.9% at 20 years (95%CI 0.724–0.871), and at 30 years it was 77.8% (95%CI 0.669–0.855) of the total knee arthropathies. The average grand total functional score increased from 61 (maximum 200) at 0 months to above 150 at ≥6 months.CONCLUSION: UKA is a good option for isolated medial compartment gonarthrosis with excellent functional outcome and good survivorship in selected patients.LIMITATION: Single center experience, retrospective. We lost 6.0% of patients during follow-up.CONFLICT OF INTEREST: None.

Revision for coronal malalignment will improve functional outcome up to 5years postoperatively.

Revision of a total knee arthroplasty (TKA) for the diagnosis of malalignment is widely performed. However, very little is known about the functional outcome in revision TKA surgery for malalignment. The aim of this study was to assess the functional outcome and to identify factors influencing the functional outcome of patients who have had a revision of a TKA for the diagnosis of malalignment at 5years follow-up. All patients with a revision of a TKA for malalignment as the primary reason were selected from a prospective database. The diagnosis of symptomatic malalignment was made by the surgeon and quantified by radiologic examination. Functional outcome was scored by the functional score of the Knee Society Clinical Rating System (fKSS) at 0, 12, 24 and 60months. Multiple imputation for missing data and multivariable analysis were performed to identify factors influencing functional outcome. After selection, 105 patients (age: 65.1 ± 9.1years, gender M:F 30:75) were eligible for outcome analysis. Functional outcome significantly improved from the preoperative (fKSS: 44.1 ± 22.0) to 5years postoperative (64.7 ± 24.0, p < 0.001) time frames. Higher degree of coronal deviation, younger age and lower preoperative KSS were found to be strongest positive influencing factors for the change in fKSS. Revision of TKA for malalignment appears to be an effective treatment to improve functional outcome up to 5years postoperatively. Higher degree of coronal deviation, younger age and lower preoperative KSS are the strongest contributing factors for functional improvement. Level III; Therapeutic prospective cohort study.

A new prediction model for patient satisfaction after total knee arthroplasty and the roles of different scoring systems: a retrospective cohort study

BackgroundAlthough total knee arthroplasty (TKA) is an efficacious treatment for end-stage osteoarthritis, ~20% of patients are dissatisfied with the results. We determined which factors contribute to patient satisfaction and compared the various scoring systems before and after surgery.MethodsIn this retrospective cohort study, 545 patients were enrolled and evaluated preoperatively and 1 year postoperatively. Patient demographics, as well as scores for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form (SF)-12, and 1989 Knee Society Clinical Rating System (1989 KSS), were recorded preoperatively and postoperatively. The possible predictors were introduced into a prediction model. Scores for overall satisfaction and the 2011 Knee Society Score (2011 KSS) were also assessed after TKA to identify the accuracy and agreement of the systems.ResultsThere were 134 male patients and 411 female patients, with an overall prevalence of satisfaction of 83.7% 1 year after surgery. A history of surgery (p < 0.001) and the 1989 KSS and SF-12 were of the utmost importance in the prediction model, whereas the WOMAC score had a vital role postoperatively (change in WOMAC pain score, p < 0.001; change in WOMAC physical function score, p < 0.001; postoperative WOMAC pain score, p = 0.004). C-index of model was 0.898 > 0.70 (95% confidence interval (CI): 0.86-0.94). The Hosmer-Lemeshow test showed a p value of 0.586, and the AUC of external cohort was 0.953 (sensitivity=0.87, specificity=0.97). The agreement between the assessment of overall satisfaction and the 2011 KSS satisfaction assessment was general (Kappa=0.437 > 0.4, p < 0.001).ConclusionA history of surgery, the preoperative 1989 KSS, and the preoperative SF-12 influenced patient satisfaction after primary TKA. We recommend the WOMAC (particularly the pain subscale score) to reflect overall patient satisfaction postoperatively.

Allergy Testing Has No Correlation with Intraoperative Histopathology from Revision Total Knee Arthroplasty for Implant-Related Metal Allergy.

Lymphocyte transformation testing (LTT) is often used in the workup for possible metal allergy after total knee arthroplasty (TKA) but the correlation of this test with other diagnostic metal-allergy findings in patients undergoing revision TKA for suspected metal allergy has not been established. A single-center, single-surgeon cohort of 19 TKAs in which both components were revised for presumed implant-related metal allergy based on history, physical, and LTT testing, to nonnickel-containing implants were retrospectively identified. Histopathologic samples obtained intraoperatively were semiquantitatively analyzed using both the Hospital for Special Surgery (HSS) synovial pathology score and the Campbell aseptic lymphocyte-dominant vasculitis-associated lesion (ALVAL) score. As histopathology control group, we included in the study an additional cohort of 17 patients who received aseptic revision TKA and had no history of reported or tested metal sensitivity. All preoperative LTT results were highly reactive to nickel. However, this did not correlate with local periarticular tissue response in 18 of 19 cases which demonstrated a low HSS synovial score (mean: 3.8 ± 2.8, of a maximum score of 28) and the low Campbell ALVAL scores (mean: 2.5/10 ± 1.3, of a maximum score of 10). There were not any significant differences between the study group (suspected implant-related metal allergy) and the control group (nonsuspected implant-related metal allergy) in regard to (1) the Campbell score and (2) the HSS synovial inflammatory score. Knee Society Clinical Rating System (KSCRS) function score improved significantly after revision (mean postoperative increase: 34.0 ± 17. 2; p < 0.001), as well as mean visual analog scale (VAS) pain (mean postoperative decrease: 33.3 ± 26.4; p < 0.01) score. The short-term survival rate (at mean follow-up of 26.1 months) of this patient cohort was 100%. In this cohort of revised TKA patients with suspected nickel allergy based on clinical presentation and LTT positive results, intraoperative histopathology was essentially normal. However, all patients with suspected nickel allergy showed a significant clinical and functional improvement with excellent short-term survival rates. The clinical significance of a positive LTT needs further study.

IN FEMALE PRIMARY OSTEOARTHRITIC PATIENTS, UNDERGOING TOTAL KNEE ARTHROPLASTY, IS GENDER-SPECIFIC CRUCIATE RETAINING HIGH-FLEXION KNEE, SUPERIOR TO STANDARD CRUCIATE RETAINING FLEXION KNEE, FROM THE VIEW OF CLINICO-FUNCTIONAL OUTCOMES.

Anthropometric measurements of the human knee, have differences in the women's and the men's knee. Total Knee Arthroplasty (TKA), aim is to relieve pain in an osteoarthritic knee, to improve the functional range of movements, and thereby improve the quality of life, of the patient. In this study, which was specically done for women patients with primary tri-compartmental osteoarthritis of the knee, the implant design for total knee arthroplasty was either “Standard CR Flex Knee” or “Gender-Specic CR High-Flex Knee”. This prospective study had a recruitment period of 2 years and a minimum follow-up period of 1 year and was done between March 2018 to February 2021. 23 female subjects aged between 51 to 80 years, were recruited in the “Standard CR Flex Knee” group and 25 female subjects aged between 51 to 80 years, were recruited in the “GenderSpecic CR High-Flex Knee” group. 60.42% (n=29) had a right sided involvement and remaining 39.58% (n=19) had a left sided involvement. Post-operative Knee Society Clinical Rating System (KSS), mean clinical outcome for “Standard CR Flex” and “Gender-Specic CR High-Flex Knee” were scored as 87.5 and 92.0 points respectively. With regard to the mean functional outcome, as per KSS both the groups averaged 85.0 points. Thus, this study could not establish any potential additional benets, by opting for the “Gender-Specic CR High-ex knee prosthesis”. Both the “Standard CR Flex Knee” and the “Gender-Specic CR High-Flex Knee” TKA yielded nearly similar clinico-functional outcomes.

A comparison between laterally wedged insoles and ankle-foot orthoses for the treatment of medial osteoarthritis of the knee: A randomized cross-over trial

Objective: To compare biomechanical and clinical outcome of laterally wedged insoles (LWI) and an ankle-foot orthosis (AFO) in patients with medial knee osteoarthritis. Design: Single-centre, block-randomized, cross-over controlled trial. Setting: Outpatient clinic. Subjects: About 39 patients with symptomatic medial knee osteoarthritis. Interventions: Patients started with either LWI or AFO, determined randomly, and six weeks later changed to the alternative. Main measures: Change in the 1st maximum of external knee adduction moment (eKAM) was assessed with gait analysis. Additional outcomes were other kinetic and kinematic changes and the patient-reported outcomes EQ-5D-5L, Oxford Knee Score (OKS), American Knee Society Clinical Rating System (AKSS), Hannover Functional Ability Questionnaire – Osteoarthritis and knee pain. Results: Mean age (SD) of the study population was 58 (8) years, mean BMI 30 (5). Both aids significantly improved OKS (LWI P = 0.003, AFO P = 0.001), AKSS Knee Score (LWI P = 0.01, AFO P = 0.004) and EQ-5D-5L Index (LWI P = 0.001, AFO P = 0.002). AFO reduced the 1st maximum of eKAM by 18% (P < 0.001). The LWI reduced both maxima by 6% (P = 0.02, P = 0.03). Both AFO and LWI reduced the knee adduction angular impulse (KAAI) by 11% (P < 0.001) and 5% (P = 0.05) respectively. The eKAM (1st maximum) and KAAI reduction was significantly larger with AFO than with LWI (P = 0.001, P = 0.004). Conclusions: AFO reduces medial knee load more than LWI. Nevertheless, no clinical superiority of either of the two aids could be shown.

Total diz artroplastisinde subvastus ve medial parapatellar yaklaşımın klinik ve radyolojik sonuçlarının değerlendirilmesi

Introduction: The aim of this study is to compare clinically and radiologically the subvatus (SV) and medial parapatellar (MPP) approaches performed in patients undergoing total knee arthroplasty (TKA) due to severe gonarthrosis. Materials and methods: Patients who underwent TKA between 2015 and 2019 were divided into two groups, SV and MPP, according to the type of approach performed. Demographic, clinical, and surgical information of the patients were evaluated. Knee Society Clinical Rating System (KSS) and visual analogue scale (VAS) scores were used for functional evaluation. AP and lateral orthoroentgenograms and knee radiographs taken at the last follow-up were used for radiological evaluation. Results: The mean duration of surgery and tourniquet was significantly higher in the SV group. (p &lt;.001 and p &lt;.001, respectively). Mean blood loss and number of blood transfusions were significantly higher in the MPP group. (p &lt;.001 and p &lt;.001, respectively). Opiate analgesic need, straight leg raising time and hospitalization time were also significantly higher in the MPP group. (p &lt;.001, p &lt;.001 and p &lt;.001, respectively). Although the KSS, VAS scores, and the range of motion at the first month were better in the SV group, there was no difference between the two groups at 6 and 12 months. Conclusion: According to this study, with the SV approach used for TKA, postoperative blood loss and the need for transfusion decreased, the duration of hospitalization was shortened, postoperative pain was less, and functional scores were better. The only disadvantage is the prolonged operation time

Management of bone deficiency by metal augmentation in total knee arthroplasty

Background Inadequate bone stock is frequently encountered in total knee arthroplasty and may be found in primary and revision procedures. Different techniques and devices for their management include additional bone resection, shifting of the components, filling the defect with cement with or without reinforcing screws or mesh, bone grafting, modular metal augmentation, or custom components. The modular augmentations are particularly useful in restoring the proper anteroposterior dimension as well as distal positioning of the joint line. In this study, the authors evaluate the use of metal augmentation for the management of deficient bone stock in total knee arthroplasty. Patients and methods A prospective study was done through the period between June 2014 and June 2017 on 30 knee arthroplasties, both primary and revision cases in 28 patients with bone deficiency consistent with Anderson Orthopedic Research Institute type II, treated by metal augmentation using different types of tibial and femoral augments applied to a posterior-stabilized prosthesis. The mean follow-up was 19 months. Eighteen cases (60%) were primary knee arthroplasties, and 12 cases (40%) were revision knee arthroplasties. Assessment at follow-up included clinical assessment through the knee society clinical rating system and radiographic assessment through the knee society roentgengraphic evaluation system. Results At the last follow-up, the average clinical knee society score was 80.4 (range from 16 to 93) compared with the average preoperative knee society score of 32 (range from 6 to 51). Only tibial radiolucent lines appeared in zones 1, 2 (nine cases), zones 3, 4 (four cases), and zone 5 in one case. All were nonprogressive radiolucent lines, except for two cases that progressed to aseptic loosening, and only one of them to a varus subsidence of the tibial implant. Conclusion Modular metal augmentation is a successful way for reconstruction of bone defects encountered in total knee arthroplasty through preservation of joint line and bone stock.

Radiographs are not sufficient for evaluation of component fit in subtle knee pain after total knee arthroplasty.

To determine the component fit by radiography or computed tomography after total knee arthroplasty and the relation of imaging with clinical examination of residual knee pain. The study was conducted in 172 patients with residual knee pain after total knee arthroplasty. The patients were examined to determine whether they experienced pain upon palpation at nine regions surrounding the tibial and femoral components, and the results were noted. The Knee Society Clinical Rating System and The Western Ontario and McMaster Universities Arthritis Index pain scale score forms were completed for all patients. Radiologic evaluation was performed using computed tomography and anteroposterior, lateral, and oblique radiographs to determine component overhang/underhang status at these nine regions. Overhang, underhang, and cortical fit groups were created based on the position of the component at the bone margin. A statistical relationship was sought between the clinical scores and the values measured to determine which imaging method showed the best correlation with clinical scores. Consistency of CT and Rx measurements was compared using the McNemar-Bowker test. Comparisons between groups were made using Student's t test for normally distributed data, and the Mann-Whitney U test. Computed tomography and radiographic measurements were similar in the medial, anterior, and lateral tibial regions. However, no similarities were observed in the anteromedial, anterolateral, posteromedial, and posterolateral tibial regions, and in the distal-medial and distal-lateral aspects of the femur. Statistical relationships among decreased clinical scores, pain with palpation, and the presence of overhang/underhang were only observed in the medial tibial region for imaging using radiography. A statistically significant relationship was observed in the medial, posteromedial, and posterolateral tibial regions, and in the distal-medial region of the femur for imaging based on computed tomography. Radiography could only aid in assessing the component fit in the anteromedial, medial, and lateral regions of the tibia in patients with residual knee pain following knee arthroplasty, but it was not sufficient in comparison with computed tomography in six other regions. Prospective study, level of evidence II.

Design Modifications of the Posterior-Stabilized Knee System May Reduce Anterior Knee Pain and Complications Following Total Knee Replacement.

In total knee arthroplasty (TKA), advances in posterior-stabilized (PS) knee implant designs address patellofemoral mechanics and cam-post engagement in an effort to reduce patellofemoral pain and improve knee kinematics. Such modifications may include improved femoral rollback, improved femoral dislocation resistance, minimized wear, and improved longevity. In this study, we compared a newer PS knee design that incorporates a left and right specific femoral component and smoother trochlear groove to improve patellofemoral mechanics with an older PS design in order to assess patellofemoral pain, manipulation rates, and revision rates. Using an institutional database, we retrospectively identified TKAs performed by the same surgeon using the Logic® PS knee system and theolder Optetrak PS knee system (Exactech Inc., Gainesville, FL, USA), with a minimum 2-year follow-up. Clinical outcomes for each cohort were measured using the Knee Society Clinical Rating System, University of California Los Angeles Activity Scale, pain visual analog scale(VAS), Veterans Rand 12-Item Health Survey, and Western Ontario and McMaster Universities Osteoarthritis Index. In addition, rates of anterior knee pain, manipulation, and revision were compared between the two knee systems, and a Kaplan-Meier survivorship curve defining failure as need for revision was calculated to allow comparison between the cohorts. From 2000 to 2018, there were 1482 TKAs performed using the Logic PS (not counting 12 patients who had died) and 445 in the Optetrak PS group (not counting 20 patients who had died). In the Logic PS and Optetrak PS groups, respectively, the average age at operation was 66.7years and 68.6years and the average body mass index was 30.8 and 31.2. Pain VAS scores were significantly lower in the Logic PS group than in the Optetrak group (1.72 vs. 2.75out of 10, respectively). There was also a significant difference inthe percentages of patients reporting anterior knee pain in the Logic group, as compared with the Optetrak group (5.6% vs. 11.8%, respectively). In addition, manipulation rates differed significantly between the Logic and Optetrak groups (0.34% vs. 10.70%, respectively). The revision rates were 1.15% for the Logic group and 2.0% for the Optetrak group. However, there was a significant difference in rates of revision performed because of osteolysis, favoring the Logic group (0.07% vs. 0.6%). The Kaplan-Meier survivorship curve shows a significant difference in time until revision between the Logic and Optetrak groups. Design modifications to improve patellofemoral mechanics demonstrated significant improvements in overall pain and patellofemoral pain and reduced manipulation rates post-operatively.

Intact, pie-crusting and repairing the posterior cruciate ligament in posterior cruciate ligament-retaining total knee arthroplasty: A 5-year follow-up.

BACKGROUNDThe posterior cruciate ligament (PCL) is important for cruciate-retaining (CR) total knee arthroplasty (TKA). Whether the entire PCL should be retained during CR-TKA is controversial.AIMTo evaluate the clinical outcomes of PCL preservation in CR-TKA and the methods used to deal with the PCL during surgery.METHODSA retrospective review of patients with osteoarthritis undergoing primary CR-TKA (176 patients, 205 knees) in our institution between March 2012 and March 2014 was performed. A PCL protector was used to preserve the intact PCL bone block. The status of the PCL was recorded during surgery. Intact PCL preserved, pie-crusting and repairing were used to balance the tension of the PCL. Range of motion (ROM) and the Knee Society Clinical Rating system (KSS) were evaluated preoperatively and at the endpoint of follow-up.RESULTSThe mean ROM of the knee was 103.2 ± 17.2°, KSS clinical score was 47.6 ± 9.5 and KSS functional score was 46.3 ± 11.9 before surgery. The mean ROM of the knee was 117.5 ± 9.7°, KSS clinical score was 89.2 ± 3.6 and KSS functional score was 84.6 ± 9.8 at 5 years follow-up. ROM, KSS clinical scores and KSS functional scores were significantly improved after surgery (P < 0.01). Thirty-two (23.7%) TKAs involved PCL pie-crusting and 18 (13.3%) involved PCL repair. Eighty-five (63.0%) TKAs applied standard operating procedures and preserved intact PCL. At 5 years follow-up, in the intact PCL group, the mean ROM of the knee was 118.0 ± 8.3°, KSS clinical score was 89.1 ± 3.7 and KSS functional score was 84.9 ± 9.6. In the PCL pie-crusting group, mean ROM of the knee was 114.0 ± 13.5°, KSS clinical score was 88.8 ± 3.4 and KSS functional score was 83.8 ± 10.5. In the PCL repair group, mean ROM of the knee was 120.3 ± 7.0°, KSS clinical score was 89.0 ± 3.6 and KSS functional score was 89.4 ± 4.5. There were no significant differences in ROM, KSS clinical scores and KSS functional scores among the three groups (P > 0.05).CONCLUSIONThe clinical outcomes of preserving the PCL in CR-TKA are encouraging. Pie-crusting and PCL repair do not affect the function. The PCL protector effectively protected the PCL bone block.

Medium-term Results Evaluation between Gender-Specific x Conventional Total Knee Arthroplasty Prostheses.

Objective To compare the postoperative functional result of total knee arthroplasty (TKA) with gender-specific prosthesis versus TKA with conventional prosthesis in a 5-year period. Methods Retrospective study with functional evaluation of 30 patients (15 patients from each group) using scores (Knee Injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities arthritis index [WOMAC], and The Knee Society Clinical Rating System [KSS]) and range of motion (ROM) as methods of assessment. Results The differences found between the score values and ROM were not statistically significant. Conclusion The gender-specific prosthesis presents functional results equal to those of conventional prosthesis after 5 years postoperatively.

Does Recession of the Posterior Cruciate Ligament Influence Outcome in Total Knee Arthroplasty?

BackgroundFor a PCL-retaining (posterior cruciate ligament) total knee arthroplasty (TKA) to function suitably, proper soft tissue balancing, including PCL recession, is required. Yet, when the recession of the PCL is needed, there is still a debate as to whether a cruciate-retaining (CR) TKA should be converted to a posterior-stabilized TKA due to the concern of instability and poorer clinical outcomes. The purpose of this study is to determine whether recession of the PCL adversely affects clinical outcomes in patients who undergo CR TKA. MethodsCR TKAs of the same design performed by the senior author (J.M.) were identified between December 2006 and July 2015. Clinical outcome measurements were collected and included the Western Ontario and McMaster Universities Osteoarthritis Index score, the Knee Society Clinical Rating System, Short Form-12 Physical Composite Score/Mental Health Composite Score, and revision rates. ResultsThere were no significant differences in clinical outcome when the PCL was retained, partially recessed, or completely released during PCL-retaining TKA (Western Ontario and McMaster Universities Osteoarthritis Index: P = .54, Knee Society Clinical Rating System: P = .42, Short Form-12 Mental Health Composite Score: P = .89, Short Form-12 Physical Composite Score: P = .527). ConclusionThis study presents evidence of similar clinical outcomes when the PCL is retained or released during PCL-retaining TKA, provided attention is paid to appropriate soft tissue balancing. CR TKA undergoing partial or complete release of the PCL should not routinely be converted to a posterior-stabilized knee design. Level of EvidenceLevel II, Prognostic study.

A 13- to 16-year clinical and radiological outcome study of the genesis II cruciate retaining total knee arthroplasty with an oxidised zirconium femoral component

PurposeThe Genesis II Total Knee Arthroplasty with an oxidized zirconium (OxiniumTM) femoral component (Smith & Nephew, Memphis, TN, USA) was introduced in an attempt to reduce polyethylene wear and osteolysis. MethodsWe retrospectively evaluated prospectively collected data from 245 consecutive patients (40 men and 205 women; mean age at surgery 70.1 years, range 44 to 85 years) who underwent 261 TKAs with a mean follow-up of 15.1 years (range 13 to 16 years). Implant failure rate, complication rate, clinical (both subjective and objective) and radiological outcomes were assessed. ResultsAt final follow-up, 24 (9.8 %) patients (24 TKAs) were lost to follow-up and 35 (14.3%) patients (35 TKAs) had died for reasons unrelated to surgery. Four TKAs, in four patients, were revised because of aseptic loosening. In five TKAs (five patients) secondary patella resurfacing was performed because of patellofemoral pain. Survivorship analysis showed a cumulative success rate of 98.4% (95% CI, 94.3% - 100%) at 15 years with revision for aseptic loosening as an end point, and 95.6% (95% CI, 92.7% - 98.7%) at 15 years with revision for any reason as an end point. All patients showed a statistically significant improvement (p = 0.01) in the Knee Society clinical rating system, WOMAC Score, KOOS Score, Oxford Knee Score and EuroQol 5D Score. Surgery fulfilled patient expectations for 90.1% of patients; in 5.4% it did not, and 4.5% declined to answer. ConclusionThis study demonstrates satisfactory long-term clinical results for this knee design.