High-flex Total Knee Arthroplasty Research Articles

Do High-Flexion Total Knee Arthroplasty Have More Adverse Events™

Introduction: High-flexion knee prosthesis was proposed to result in better outcomes after knee arthroplasty. However, latest meta-analysis revealed that this implant indeed only produced better range of motion (ROM) and no benefits in other functional outcomes, including weight-bearing flexion. Moreover, recent studies suggested that more complications occurred in high-flexion total knee arthroplasty (TKA) instead. Objectives: This study focuses on the adverse events of high-flexion TKA compared to standard TKA in mid to long term of follow-up. Methods: Systematic search was done in online databases, i.e. Pubmed, ScienceDirect, ClinicalKey. We only included studies with a minimum follow-up duration of 5 years, expecting that this mid to long term follow-up could provide a better picture of the outcomes. Results: Seven studies were included in the final quantitative analyses, involving a total of 2,693 knees in high-flexion TKA and 3,892 knees in standard TKA. High-flexion TKA significantly had higher revision surgery compared to standard TKA (p = 0.03), 41(1.52%) and 53 (1,36%) knees, respectively. Loosening was not statistically different between those groups. Generally, radiolucent line was also more frequently observed in high-flex TKA (p = 0.01), 7.43% V 3.83% at femoral side and 5.69% V 4.41% at tibial side. Although infection and instability were higher in high-flexion knee, only a few studies found the occurrence of these parameters. Four studies evaluated the incidence of osteolysis and none was found in both groups. Conclusion: Considering that high-flexion TKA may only yield on better ROM but carry a bigger risk of adverse events, one has to cautiously weighing up the benefits and risks when planning of delivering a high-flexion TKA.

A review on flexion angle in high-flexion total knee arthroplasty for indonesian’s need

Total Knee Arthroplasty (TKA) proposed as an alternative treatment for damaged knee joints of humans is reviewed. The commercial application of TKA can help patients to improve their daily normal activities. Here the high-flex type total knee arthroplasty (High-Flex TKA) is typically designed for the patient’s convenience on which the greater range of motion can be adjusted for extreme activities such as Seiza and Muslim praying. However, the present High-Flex TKAs have not fulfilled the needs of Indonesians for religious activities with a flexion angle of 150°–165°. Therefore, this review aims to examine the flexion range of High-Flex TKAs proposed for the needs of Indonesians. This study is a narrative review, all studies published and reviewed are related to the range of flexion angles on the use of products from many manufacturers and various types that have been used by patients, as well as the development of a CAD-based TKA design. It was proposed in the present study that the flexion angle on High-Flex TKAs may be optimized by thickening the posterior femoral condyle, creating a medial pivot system, and applying a single radius system on the femoral component. Whereas, the tibial insert component could be designed by setting up the posterior tibial slope, and creating a post-cam stabilizer mechanism. Many knowledge gaps related to the population of research objects, lack of research on extreme angles, development of TKA components, are discussed. Further needs of extensive research on TKA in Mongoloid races are anticipated to be introduced for extreme angles and most comprehensive product development for optimization of the flexion angle.

The High Flex Total Knee Arthroplasty\u2014Higher Incidence of Aseptic Loosening and No Benefit in Comparison to Conventional Total Knee Arthroplasty: Minimum 16-Years Follow-Up Results

PurposeThis prospective randomized study compares the clinical and radiographic long-term results at least 16 years after total knee arthroplasty (TKA) between a mobile-bearing high flex and a fixed-bearing posterior-stabilized knee.MethodsIn 2000, we included 60 patients who underwent a TKA. Patients were divided into two groups. At the time of the follow-up after a minimum of 16 years (16.5 years ± 0.6), 16 patients had died for causes unrelated to the operation, 15 were lost to the follow-up. Five patients of the high flex group had a revision. The final evaluation included the hospital for special surgery score (HSS) and radiographs. Using the X-rays and the Knee Society Roentgenographic Evaluation and Scoring System, radiolucent lines and the maximal knee flexion were determined.ResultsNo significant differences between the two groups were found. The mean HSS score of LPS group patients was 87.9 (± 10.6) points and that of the high flex group was 93.1 (± 7.4) points. Five patients of the high flex group had undergone a reoperation. One knee was revised for painful mid-flexion instability and the others for symptomatic aseptic loosening of the components.ConclusionThe long-term follow-up does not show any clear benefits and even a higher incidence of implant loosening using the mobile-bearing high-flex knee.

Uncemented monoblock trabecular metal posterior stabilized high-flex total knee arthroplasty: similar pattern of migration to the cruciate-retaining design — a prospective radiostereometric analysis (RSA) and clinical evaluation of 40 patients (49 knees) 60 years or younger with 9 years’ follow-up

Background and purpose — Uncemented monoblock cruciate retaining (CR) trabecular metal (TM) tibial components in total knee arthroplasty (TKA) work well in the long-term perspective in patients ≤ 60 years. Younger persons expect nearly normal knee flexion after TKA, but CR implants generally achieve less knee flexion compared with posterior stabilized (PS) implants. Cemented PS implants have higher revision rate than CR implants. Can an uncemented monoblock PS TM implant be used safely in younger patients?Patients and methods — 40 patients (49 knees) age ≤ 60 years with primary (20 knees) or posttraumatic osteoarthritis (OA) were operated with a high-flex TKA using an uncemented monoblock PS TM tibial component. Knees were evaluated with radiostereometric analysis (RSA) a mean 3 days (1–5) postoperatively, and thereafter at 6 weeks, 3 months, 1, 2, 5, and 9 years. Clinical outcome was measured with patient-related outcome measures (PROMs).Results — The implants showed a pattern of migration with initial large migration followed by early stabilization lasting up to 9 years, a pattern known to be compatible with good long-term results. Clinical and radiological outcome was excellent with 38 of the 40 patients being satisfied or very satisfied with the procedure and bone apposition to the entire implant surface in 46 of 49 knees. Mean knee flexion was 130°. 1 knee was revised at 3 months due to medial tibial condyle collapse.Interpretation — The uncemented monoblock PS TM implant works well in younger persons operated with TKA due to primary or secondary OA.

Results of High-Flex Total Knee Arthroplasty: Minimum 3-Year Follow-Up Result

Purpose: The purpose of this study was to evaluate the results of high-flexion total knee arthroplasty. Materials and Methods: We evaluated 355 patients (372 cases) who underwent total knee arthroplasty using high-flexion implants from January 2005 to December 2011. The patients included 36 men and 336 women with a mean age of 70.6 (52-88 years) years. Average follow-up duration was 59 months (36-77 months) months. Three types of high flexion implants were used in this study. We performed preoperative assessment and last follow-up clinical evaluation was performed using range of motion (ROM), knee score and function score according to the knee society clinical rating system and complications. Radiologic evaluation was performed using plain radiographs to evaluate loosening or osteolysis. Results: The mean ROM increased from 114.9° preoperatively to 127.0° at the final follow-up. The average knee score improved from 60.5 points preoperatively to 90.9 points at final follow-up and knee function score improved from 49.0 to 84.4 points. The clinical results were improved in each type of implants. A radiolucent line was detected in 2 cases in the Sigma rotating platform flexion group and patellar tendon rupture occurred in 1 case in the NexGex legacy posterior-stabilized-flex group. Infection occurred in 2 cases after 2 and 5 years postoperatively in the Scorpio non-restrictive geometry group and were treated with revision arthroplasty. No significant loosening was observed. Conclusion: This study obtained good results after total knee arthroplasty using high-flexion implants, and no loosening was observed. There were no differences in the type of implants in regard to the ROM and clinical variables.

Clinical outcomes after high-flex versus conventional total knee arthroplasty.

To compare clinical outcomes after high-flex versus conventional total knee arthroplasty (TKA). A systematic review and meta-regression were performed to compare post-operative outcomes between the two types of prostheses. Relevant randomized controlled trials were identified from MEDLINE and Scopus up to November, 2014. Fourteen of 369 studies were eligible; 14, 7, 6, 5, 3, 12 and 7 studies were included in the pooling of maximum knee flexion, Knee Society Knee Score (KS), Knee Society Function Score (FS), Hospital for Special Surgery score (HSS), short-form (SF) physical activity score, post-operative complications (DVT, fractures, infection) and revision TKA, respectively. The high-flex TKA had 1.97° [95% confidence interval (CI) 0.37, 3.57], -0.86 (95% CI -1.65, 0.07) and -1.34 (-2.57, -0.11) higher mean maximum knee flexion, KS and FS when compared to conventional TKA. However, there were non-significant differences in HSS, SF-36 (physical), complications and revision TKA. This study suggests that there are improvements in post-operative knee range of motion and knee scores in high-flex TKA implants when compared to conventional TKA implants; however, the difference was very small and therefore might not have any clinical impact. Therefore, conventional TKA can be used as a substitute. However, cost-effective analysis should be performed to make appropriate selections in the future. There are no statistically significant differences in terms of HSS, quality of life, complications and revisions between the groups. I.

No Clinical Benefit of High-Flex Total Knee Arthroplasty. A Meta-Analysis of Randomized Controlled Trials

The application of high-flex prosthesis in total knee arthroplasty (TKA) is an area of continuing debate. Thus, we conducted a meta-analysis of randomized controlled trials (RCTs). A literature search was performed in PubMed, EMBASE and the Cochrane database. 10 trials involving 1230 knee joints were eligible for our meta-analysis. No significant difference was observed between the two designs regarding postoperative range of flexion, clinical scores, quality of life outcomes, or complication rate. Moreover, the advantage of high-flex implants for patients with high preoperative range remained not statistically significant and high-flex design in NexGen system showed a marginal improvement in the postoperative range of flexion. Based on current findings, high-flex prosthesis did not appear to confer any benefit as compared to standard prosthesis.

Comparable short-term results seen with standard and high-flexion knee arthroplasty designs in European patients

PurposeIn a prospective study we evaluated outcomes of total knee arthroplasty (TKA) procedures in 62 patients with a follow up of 12 months to test our hypothesis that high-flexion CR (cruciate retaining) TKA provides a better range of motion and better outcome than standard CR design in Central European patients with their special problems and demands. MethodsPatients were randomly divided into two groups (high flex vs. standard). The outcome was determined by measuring maximum knee flexion and using the KS-score and the SF-36 score. ResultsAfter 12 months ability to flex the knee significantly improved in both groups to 115° (SD 11) in the high flex group versus 119° (SD 12) in the standard group. There was no difference between the designs regarding maximum flexion (p = 0.78). Overall clinical rating scores significantly improved in both groups, but there was no difference between groups at one year after surgery (p (KSS) = 0.7 and p (SF-36) = 0.63). KS-score values improved from 25 points to 89 points for standard TKAs and from 20 points to 90 points for high flex TKAs. SF-36-score “Physical Functioning” values improved from 33 points to 66 points for standard TKAs and from 27 points to 63 points for high flex TKAs. ConclusionOur results confirm known good results of the procedure and suggest that the benefit of high flex knee designs is similar to standard knee designs one year after index surgery. Further studies are required to evaluate long-term results of both designs.

Do patients care about higher flexion in total knee arthroplasty? A randomized, controlled, double-blinded trial

BackgroundLittle information exists to support that patients care about flexion beyond what is needed to perform activities of daily living (ADL) after Total knee arthroplasty (TKA). The purpose of this study was to investigate if the achievement of a higher degree of knee flexion after TKA would result in a better patient perceived outcome.MethodsThe study is a randomized, double-blinded, controlled trial in which 36 patients (mean age: 67.2 yrs) undergoing one-stage bilateral TKA randomly received a standard cruciate-retaining (CR) TKA in one knee and a high-flex posterior-stabilized (PS) TKA in the contra lateral knee. At follow-up ROM, satisfaction, pain, “feel” of the knee and the abilities in daily activities were assessed.ResultsAt 1-year follow-up we found an expected significantly higher degree of knee flexion of 7° in the high-flex knees (p = 0.001). The high-flex TKA’s showed a mean active flexion of 121°. In both TKA’s the median VAS pain score was 0, the median VAS satisfaction score was 9, and the median VAS score of the patient “feel” of the knee was 9 at 1-year follow-up. Further, there were no significant differences between the knees in the performance of daily activities.ConclusionsAs expected the high-flex TKA showed increased knee flexion, but no significant differences in the patient perceived outcomes were found. This suggests little relevance to the patients of the difference in knee flexion – when flexion is of this magnitude – as pain free ROM and high patient satisfaction were achieved with both TKA’s.Trial registrationClinicalTrials.gov: NCT00294528

The Mid-Term Results of High-Flex Total Knee Arthroplasty: Minimum 5-Year Follow-Up Results

The Mid-Term Results of High-Flex Total Knee Arthroplasty: Minimum 5-Year Follow-Up Results

2009 Marshall Urist Young Investigator Award: How Often Do Patients with High-Flex Total Knee Arthroplasty Use High Flexion?

2009 Marshall Urist Young Investigator Award: How Often Do Patients with High-Flex Total Knee Arthroplasty Use High Flexion?

2009 Marshall Urist Young Investigator Award: How Often Do Patients with High-Flex Total Knee Arthroplasty Use High Flexion?

Although high-flexion TKA designs aim to safely accommodate deep flexion, it is unknown how often patients use deep flexion outside the laboratory. We used a validated smart-activity monitor to document the prevalence of knee flexion greater than 90 degrees in 20 consecutive patients (21 knees) who had high-flexion TKAs, at a minimum of 2 years' followup. Patients wore the device continuously for a mean of 35.7 +/- 0.5 hours. The 21 knees flexed more than 90 degrees for an average of 10 +/- 3.8 minutes (0.5%). Activities performed with flexion greater than 90 degrees were, on average, 70% in single-limb stance, 12% moving from sitting to standing, 8% walking, 7% moving from standing to reclining, 2% stepping, 0.9% moving from lying to standing, and 0.1% running. Eight knees flexed greater than 120 degrees for an average of 2.2 minutes (range, 0.2-15 minutes), or 0.1% of the testing time. Activities performed with flexion greater than 120 degrees were, on average, 90% in single-limb stance, 6% moving from sitting to standing, 3% walking, 0.6% moving from standing to reclining, 0.3% stepping, and 0.1% moving from lying to standing. Peak flexion used at any time during testing was, on average, 84% +/- 11% of maximum postoperative flexion (125 degrees +/- 12 degrees). These patients rarely used deep flexion. Level IV, therapeutic study.

A Comparison of the Functional Results of High-Flex Total Knee Arthroplasty - LPS-Flex vs. Scorpio-Flex TKA -

Purpose: This study compared the clinical and functional results of LPS-Flex with those of Scorpio-Flex TKA. Materials and Methods: Fifty cases of High-Flex TKA (24 LPS-Flex and 26 Scorpio-Flex) were analyzed retrospectively. All the procedures were performed during the same period by the senior author and the patients were followed-up for more than 5 years. A functional evaluation was performed by a questionnaire on the high flexion-related activities, including cross-leg sitting, squatting, standing from the floor, standing from a chair and ascending and descending stairs. Each function was classified by the patients into five grades. The clinical evaluation included the range of motion, the Knee Society Knee Score and Function Score (KSKS & KSFS), the WOMAC score and the patient’s satisfaction score. Results: The functional evaluation showed a better result in the LPS-Flex group for the cross-leg sitting function (p=0.039) but there was no difference in the other functions. The clinical evaluation showed more flexion in the LPS-Flex group than that in the Scorpio-Flex group (p=0.044) but there were no difference in the KSKS, KSFS, WOMAC score and the patient's satisfaction score. Conclusion: LPS-Flex TKA showed better functional results for cross-leg sitting than did Scorpio-Flex TKA. This difference was attributed to the LPS-Flex group having more flexion than that of in the Scorpio-Flex group.

Clinical and radiological results of high flex total knee arthroplasty: a 5 year follow-up

In a prospective randomized study, we compared the results after implantation of the mobile bearing high flex TKA with a fixed bearing posterior stabilized TKA in 60 patients (30 patients each group). We evaluated the hospital for special surgery-score (HSS) and different radiological parameters preoperatively, as well as 3 months, 3 and 5 years postoperatively. Three months postoperatively, the high flex group showed better results in scores for pain, ROM (122.5 degrees vs. 107.33 degrees), as well as in the overall HSS (87.21 vs. 82.68 points). Three and 5 years postoperatively, there were no differences between both the groups in all scores, but the HSS is still increasing. The theoretical advantages of the mobile bearing knee prostheses were reflected in the clinical results, only partly and temporarily.

A Comparative Study between High-Flex and Non High-Flex Total Knee Arthroplasty

Pur p ose: The purpose of this study was to compare the clinical results of a high-flex design (S corpioflex Ⓡ , S tryker) in total knee arthroplasty with those of a non-high-flex design (S corpio Ⓡ PS type, S tryker). Mat e r ia ls and Met h ods: Fifty-two knees with at least 120 degrees of further flexion preoperatively underwent total knee arthroplasty. Of the 52 knees, there were 35 knees in the high-flex design (H F group) and 17 knees in the non high-flex design (non-H F group). The clinical results were evaluated by postoperative further flexion at 3 months, 6 months, 1 year, 2 years and 3 years, as well as by Del ta flexion, which means postoperative flexion improvement. The Knee Soci ety Score and X-rays were evaluated preoperatively and at the 3-year follow-up. Resul ts : The H F group showed significantly greater flexion than the non-H F group at 3 months postoperatively (p=0.000). The delta flexion was also greater in the HF group at 3 months postoperatively (p=0.000). The Knee Soci ety Score and X-rays were similar in the two groups at the final follow-up (p >0.05).

Early results of high-flex total knee arthroplasty: comparison study at 1 year after surgery

We compared clinical [including maximal flexion and range of motion (ROM)] and radiographical outcomes of high-flex versus conventional implants for total knee arthroplasty (TKA) after 1 year. We also analyzed the factors affecting postoperative ROM in high-flex implants. The high-flex group (n=90) had an average maximal flexion of 129.8 degrees (standard deviation (SD), 5.2 degrees ) significantly higher than the 124.3 degrees (SD, 9.2 degrees ) of the conventional group (n=90), especially for patients with less than 90 degrees of knee flexion (P<0.05). There was no significant difference in hospital for special surgery (HSS) score between the two groups. No knee developed osteolysis, aseptic loosening, or other complications. We found that, for high-flex implants, preoperative ROM had a significant effect on postoperative ROM.

The Early Results of High-Flex Total Knee Arthroplasty: A Minimum of 2 Years of Follow-up

We retrospectively reviewed our first 25 cases of high-flex total knee arthroplasty (TKA) with an average follow-up of 28 months. The results were compared to a matched group of posterior stabilized (PS) TKA. There was no significant difference in Knee Society Scores between the 2 groups. The high-flex group had an averaged 138° of knee flexion, which was significantly higher than the PS group (average, 126°). Eighty percent of patients in high-flex group were able to squat, which was significantly higher than in PS group (32%). In patients with a small bone frame, occasionally, their bone stock of the posterior femoral condyle is inadequate for high-flex TKA. For the patients without special demands, the additional knee flexion from high-flex design made no significant difference on the results.