Anatomic Graduated Component Total Knee Research Articles

The role of the posterior cruciate ligament in total knee replacement

ObjectivesThe purpose of this study was to examine the effect of posterior cruciate ligament (PCL) retention, PCL recession, and PCL excision during cruciate-retaining total knee replacement.MethodsA total of 3018 anatomic graduated component total knee replacements were examined; 1846 of these retained the PCL, 455 PCLs were partially recessed, and in 717 the PCL was completely excised from the back of the tibia.ResultsClinical scores between PCL groups favored excision for flexion (p < 0.0001), and recession and retention for stairs (p < 0.0001). There was a mild difference in long-term all-cause aseptic survivorship between PCL-retained (96.4% at 15 years) combined with PCL-recessed groups (96.6% at 15 years) when compared with the PCL-excised group (95.0% at 15 years) (p = 0.0411, Wilcoxon; p = 0.0042, log-rank), as well as tibial or femoral loosening, which reported prosthesis survival of 97.8% at 15 years for PCL-retained knees, 98.2% for recessed knees, and 96.4% for excised knees (p = 0.0934, Wilcoxon; p = 0.0202, log-rank).ConclusionsDespite some trade off in clinical performance, if the PCL is detached at the time of operation, conversion to a posterior-stabilised prosthesis may not be necessarily required as long as stability in the anteroposterior and coronal planes is achieved.

Long-Term Follow-Up of Anatomic Graduated Component Total Knee Arthroplasty: A 15- to 20-Year Survival Analysis

The aims of this study were to determine survival rate, the clinical performance, and radiologic results of an Anatomic Graduated Component (AGC) total knee arthroplasty (TKA). Survival analysis was assessed by analyzing all hospital records of 211 AGC TKAs in 177 patients after 15 to 20 years. The survival rate was 87%, with failure defined as revision for any reason including infection. The main reasons for failure were infection and failure of the metal-backed patellar component. Clinical evaluation of 30 patients (33 TKAs) and questionnaires of 20 patients (23 TKAs) were taken, showing moderate to good results (mean Knee Society Score, 51; mean Western Ontario and McMaster Universities Osteoarthritis index, 82; mean University of California Los Angeles score, 4). Radiologic evaluation of 13 TKAs in 12 patients showed that none was suspect for loosening. Three knees showed significant medial wear but no clinical complaints. In conclusion, this is one of the first studies showing that AGC total knee prosthesis has good results 15 to 20 years after surgery.

Validity of published outcome data concerning Anatomic Graduated Component total knee arthroplasty: a structured literature review including arthroplasty register data

Total knee arthroplasty (TKA) as a treatment for end-stage osteoarthritis of the knee shows good results in terms of patient satisfaction. For the assessment of outcome and revision rate after total joint arthroplasty, there are two major data sources: clinical studies and national arthroplasty registers. The purpose of this study was to analyse the outcome of Anatomic Graduated Component (AGC) TKA reported in clinical studies and to perform a comparison with the outcome reported by national arthroplasty registers. A systematic literature review was performed using standardised methodology in order to determine the outcome and revision rate of AGC TKA. In a comprehensive meta-analysis of clinical studies and worldwide register results we examined the quality of the basic data and the occurrence and influence of potential bias factors. Confidence intervals were calculated to determine the statistical significance of differences. We found significant differences as regards the revision rate measured in revisions per 100 observed component years. Compared to worldwide register data it turned out to be significantly lower in clinical studies published by the implant development team. Actually, they reported a revision rate of 0.18 revisions per 100 observed component years, whereas annual reports of national arthroplasty registers report 0.74 revisions per 100 observed component years. A comparison of the results from national arthroplasty registers of different countries revealed a significantly higher revision rate for Denmark in relation to worldwide register data. A conventional meta-analysis of clinical studies is affected by the influence of the development team and therefore subject to bias. For the assessment of outcome arthroplasty register data should be rated as superior and, being used as reference data for the detection of potential bias factors in the clinical literature, could make an essential contribution to the quality of scientific meta-analysis.

A Comparison in Proximal Tibial Strain Between Metal-Backed and All-Polyethylene Anatomic Graduated Component Total Knee Arthroplasty Tibial Components

Loading in total knee arthroplasty (TKA) is multifactorial and dependent on alignment, ligament balance, patient, and implant factors. Abnormal loading has been linked to clinical failure; however, the respective contribution of each factor to failure is not well known. This study defined the effect of metal backing on loading patterns in the proximal tibia. Composite tibiae were implanted with metal-backed and all-polyethylene Anatomic Graduated Component TKA tibial components (Biomet, Inc, Warsaw, Ind) and coated with photoelastic material allowing full-field dynamic strain quantification. In simulated varus loading distributions, significant increases in measured strain were observed ranging from 40% to 587% for all-polyethylene vs metal-backed tibial components. Higher observed strains in the proximal tibia observed with all-polyethylene tibial components could possibly explain increased clinical failure rates observed with this TKA design.

Twenty-Year Survivorship of Cementless Anatomic Graduated Component Total Knee Arthroplasty

There is a renewed interest in cementless total knee arthroplasty (TKA) due to improved biomaterials, desire for decreased surgical times and the potential increased longevity. Seventy-three cementless TKAs (AGC, Biomet, Warsaw, Ind) were performed from 1984 to 1986. All components were implanted without cement and without screws and obtained minimum 10 years of follow-up. No patient was lost to follow-up. Fifteen failures occurred, including 12 failed metal-backed patellae, and survivorship for aseptic loosening of any component was 76.4% at 20 years. Two tibial components failed of aseptic loosening at 1.1 and 2.2 years. Excluding patella failures, the survivorship for the cementless tibial component was 96.8% at 20 years. There were no femoral component failures. After eliminating patella failures, this cementless monoblock tibial component without screws demonstrated excellent 20-year survivorship.

Hybrid Total Knee Arthroplasty

A retrospective study of 201 anatomic graduated component total knee arthroplasties implanted with hybrid fixation at the authors' center was performed in response to conflicting data in the literature concerning the benefits of a hybrid method. Selection for hybrid fixation was nonrandomized and based on femoral component fit. Survivorship analysis was performed, and rates of radiolucent lines surrounding the femoral component and occurrence of osteolysis were noted. At 7 and 13 years, survivorship with tibial or femoral revision as the end point was 0.9926 and 0.9732, respectively. Radiolucencies were found adjacent to 15 femoral components at final followup (seven in Zone 1, three in Zone 2, five in Zone 3, one in Zone 4, two in Zone 5, zero in Zone 6). Osteolysis was observed in one knee after secondary evaluation. Hybrid fixation in a selected patient population can result in excellent results in middle to long-term followup.

Long-term followup of nonmodular total knee replacements.

The purpose of the current study was to evaluate and determine the mechanism and etiology of failure of components that failed in long-term followup of Anatomic Graduated Component total knee replacements. The authors previously reported the survivorship of 4583 Anatomic Graduated Component total knee arthroplasties done during a 17-year period. The current study was done to evaluate the etiology and cause of failure of the components that failed. There were six (0.18%) failures of the femoral component. There were 21 tibia components that failed (0.46%). Twelve tibial components failed because of an osteonecrotic lesion in the medial tibia plateau. The clinical survival rate with revision or loosening of one or more components was 98.9% at 15 years. No component was revised for polyethylene wear or osteolysis. This total knee replacement has proved to have minimal wear and excellent longevity with time with no revisions between 10 and 15 years despite having nearly flat-on-flat geometry and retaining the posterior cruciate ligament. The most common cause for revision (12 tibial components) was because of an osteonecrotic lesion in the medial tibia plateau, which developed after surgery and led to loosening.

Ten to fourteen year survival and functional analysis of the AGC total knee replacement system

A study of 562 Anatomic Graduated Component (AGC) total knee arthroplasties that were performed in 402 patients between November 1986 and September 1990 is reported. All patients had implantation with a cemented posterior cruciate-retaining design, with resurfacing of the patella using all polyethylene patella components. Mean age at surgery was 71 years (range 41–92 years). Patients were followed for a minimum of 10 years (range 10–14 years). Nine knees were lost to follow-up (1.4%). The mean Knee Society Score for pain and function were analyzed by Charnley categories: Category A — 97 (pain) and 89 (function); Category B — 91 (pain) and 84 (function); and Category C — 89 (pain) and 62 (function). The survival analysis at 14 years was 97% with revision for any reason as the endpoint and the authors continue to utilize this implant system.

Long-term followup of anatomic graduated components posterior cruciate-retaining total knee replacement.

The purpose of the current study was to evaluate the authors' 15-year experience with the Anatomic Graduated Components total knee replacement. This is a report of the survivorship of 4583 Anatomic Graduated Component total knee arthroplasties. Kaplan-Meier survival analyses were performed with the end point defined as radiographic loosening, revision, or both. This end point was subdivided into the best case scenario in which it was assumed that all the patients lost to followup were doing well throughout the study and a worst case scenario in which it was assumed that all patients lost to followup had failed results at their last clinic visit. There were six (0.18%) femoral, 21 (0.46%) tibial, and 180 (4.2%) all-polyethylene patellar component failures secondary to aseptic loosening. All femoral components and 90% of the tibial components were revised; however, only 15 patellar components were revised. The clinical survival rate with revision of one or more of the components was 98.86% at 15 years. Despite having nearly flat-on-flat geometry and retaining the posterior cruciate ligament, which should increase the stresses in the polyethylene and at the bone-cement interface, this total knee replacement has proved to have minimal wear and excellent longevity with time. The authors think this is a result of the direct compression molded polyethylene articulation and the nonmodular configuration that incorporates metal backing on the tibial component and eliminates back-sided tibial component polyethylene wear.

Low-conforming all-polyethylene tibial component not inferior to metal-backed component in cemented total knee arthroplasty: Prospective, randomized radiostereometric analysis study of the AGC total knee prosthesis

In a prospective, randomized study of 40 patients, the quality of fixation of cemented metal-backed versus all-polyethylene tibial components of the unconstrained anatomic graduated component total knee arthroplasty design was studied during 2 years using radiostereometric analysis (RSA). The shape, as well as the articulating geometry, of the implants was identical, as was the operative technique and the postoperative regimen. In this study, no negative consequences regarding the quality of fixation using an all-polyethylene tibial component with unconstrained articulating surfaces could be identified. In all aspects, the all-polyethylene tibial components displayed migration on par with, or sometimes lower than, their metal-backed counterparts. The rotations of the all-polyethylene components were equally low as for the metal-backed components, and maximum lift-off was significantly lower than for the metal-backed implants. We could not identify any collapse of the bone at the medial condyle or increased subsidence at the medial part of the tibia or increased rates of radiolucent lines in the knees with all-polyethylene components. All all-polyethylene implants seemed to be stable within the resolution of RSA between 1 and 2 years, a finding known to be of positive prognostic significance regarding future aseptic loosening.

Patellar Complications (Total Knee Arthroplasty) Effect of Lateral Release and Thickness

One thousand, one hundred forty-six Anatomic Graduated Component total knee arthroplasties performed between 1987 and 1989 were used to investigate the effects of patellar thickness alone or coupled with lateral retinacular release on initial patellar complications and maximal flexion. Lateral release was found not to be statistically significant regarding radiolucency, patellar prosthesis loosening, or an increase or decrease in flexion. However, total knee arthroplasties in which a lateral release was done, which either saved the superior lateral genicular artery or sacrificed the superior lateral genicular artery, were found to increase the incidence of initial patellar fractures and/or loosening (complications within 1 year) when compared with total knee arthroplasties in which a lateral release was not performed. There was no statistical difference in failure rates regarding fractures and/or loosening of the patella between lateral releases in which the superior lateral genicular artery was saved and the lateral releases in which the superior lateral genicular artery was sacrificed. A difference in postoperative patellar thickness compared with preoperative patellar thickness was found not to be significant to initial patellar fracture and/or loosening, patellar fracture alone, patellar loosening alone, radiolucency, the need for a lateral release, or to an increase or decrease in flexion. Lateral release and patellar thickness had no significant effect on patellar fracture and/or loosening.

Osteolysis around cementless porous-coated knee prostheses

The Journal of Bone and Joint Surgery. British volumeVol. 77-B, No. 4 ArticlesFree AccessOsteolysis around cementless porous-coated knee prosthesesCG Moran, IM PinderCG MoranSearch for more papers by this author, IM PinderSearch for more papers by this authorPublished Online:1 Jul 1995https://doi.org/10.1302/0301-620X.77B4.7677886AboutSectionsPDF/EPUB ToolsAdd to FavouritesDownload CitationsTrack CitationsPermissions ShareShare onFacebookTwitterLinked InRedditEmail FiguresReferencesRelatedDetailsCited byUncemented Tantalum Monoblock Tibial Fixation for Total Knee Arthroplasty in Patients Less Than 60 Years of AgeJournal of Bone and Joint Surgery, Vol. 100, No. 10Total Knee Arthroplasty Using Cementless Porous Tantalum Monoblock Tibial Component: A Minimum 10-Year Follow-UpThe Journal of Arthroplasty, Vol. 31, No. 10Early Failure of Cementless Porous Tantalum Monoblock Tibial ComponentsThe Journal of Arthroplasty, Vol. 28, No. 9Twenty-Year Survivorship of Cementless Anatomic Graduated Component Total Knee ArthroplastyThe Journal of Arthroplasty, Vol. 25, No. 4Hybrid Total Knee Arthroplasty Vol. 77-B, No. 4 Metrics History Published online 1 July 1995 Published in print 1 July 1995 InformationCopyright © 1995, The British Editorial Society of Bone and Joint Surgery: All rights reservedPDF download