Why are total knee replacements revised?: analysis of early revision in a community knee implant registry

Since 1991, 5760 knee arthroplasty procedures done by 53 surgeons have been registered in a community joint implant registry and were reviewed regarding initial revision done within the healthcare system. The 168 revisions done represented 2.9% of the knee arthroplasties between September 1991 and December 2002. Survival was defined as the absence of revision surgery. Death was considered a censored event. Cumulative survival rates for the different total knee arthroplasty configurations were: cemented total knee arthroplasty with all-polyethylene tibia, 99.2%; cemented total knee arthroplasty with metal-backed tibia, 96.3%; hybrid total knee arthroplasty, 89.3%; and unicondylar knee arthroplasty, 87.2%. Cemented total knee arthroplasty with metal-backed tibia had better survival than hybrid total knee arthroplasty, ingrowth total knee arthroplasty, and unicondylar knee arthroplasty. Cemented total knee arthroplasty with a metal-backed tibia did not have better survival than cemented total knee arthroplasty with an all-polyethylene tibia. Gender was not related to survival. Age was related to survival, with older patients' knees surviving longer. Aseptic loosening or wear was the cause of revision in 40.8% of patients having total knee arthroplasty and 46.6% of patients having unicondylar knee arthroplasty, whereas progression of arthritis necessitated unicondylar knee revision in 51.2% of patients having that procedure. This study presents further evidence of the value of and ongoing need for total joint registries. Cemented total knee arthroplasty with all-polyethylene tibia and with metal-backed tibia showed more than 95% 10-year cumulative survival. Hybrid total knee arthroplasty, ingrowth total knee arthroplasty, and unicondylar knee arthroplasties did not show such good results.     

Influence of tibial bone quality on loosening of the tibial component in total knee arthroplasty for rheumatoid arthritis: long-term results

This study examined the relationship between the bone quality of the proximal tibia, which was quantitatively investigated by histomorphometric method at the time of total knee arthroplasty, and the occurrence of loosening of an all-polyethylene tibial component in nine rheumatoid arthritis patients. Despite severe osteoporosis, there was no loosening after 12.8 years. These results suggest that even severe osteoporosis does not influence the occurrence of loosening of a cemented, all-polyethylene tibial component in rheumatoid patients with low activity levels. We recommend the use of all-polyethylene tibial component for low-activity patients.     

Medial screws and cement: a possible mechanical augmentation in total knee arthroplasty

The purpose of this study was to determine whether screws placed beneath the medial tibial plateau in cemented total knee arthroplasty helps prevent collapse of the medial tibia. A previous study found that the AGC all-polyethylene tibial component had a 14% rate of collapse of the medial subchondral region in the first postoperative year. Of 536 implanted AGC all-polyethylene tibial components, 20 had screws inserted beneath the medial tibial plateau. No AGC all-polyethylene tibial components with screws failed because of aseptic loosening or collapse of the medial tibial plateau. The study included 125 cemented metal-backed total knee arthroplasties with screws inserted beneath the medial tibial plateau. We also found 2 cases of collapse of the medial tibial plateau and 1 case of collapse on the lateral side. No revisions were performed. The placement of screws beneath the medial tibial plateau to fill large defects is an excellent precaution against collapse of the medial tibia.     

The all-poly tibia in patients <60: Not an affordable care act alternative

Patients aged <60 years who have an all-polyethylene tibial component implanted with cement during total knee arthroplasty are at high risk for failure and need for revision. The all-polyethylene tibial design fails at a high rate because it cannot withstand the demands of this age group for the forces exerted during higher activity levels and the length of use expected after total knee arthroplasty. Patients implanted with metal-backed tibial components have longer clinical survivorship and less need for revision. This article outlines the dangers of a cemented all-poly tibia in patients <60 years.     

A randomized comparison of all-polyethylene and metal-backed tibial components

Clinical failures of all-polyethylene tibial components in total knee arthroplasty generally have been failures of design, not materials. The current study was designed to compare a modern congruent all-polyethylene tibial component with a metal-backed tibial component with the same articular design and geometry. All patients older than 60 years of age requiring total knee arthroplasty were randomized prospectively to receive either a cemented posterior cruciate ligament-retaining all-polyethylene component or a metal-backed tibial component with identical articular surfaces. All patients received identical cemented femoral and all-polyethylene patellar implants. The mean age of the patients was 69 years, and the mean American Society of Anesthesiology score was 3. The diagnosis was osteoarthritis in 92% of this population. Three hundred twenty-four total knee arthroplasties in 296 patients were performed; 213 joints (111 all-polyethylene tibias and 102 metal-backed tibias) with a minimum of 3 years followup (mean, 49 months) are reported. The preoperative Knee Society knee score in the group of patients who received an all-polyethylene tibial component was 38 points, improving to 84 points at latest followup, whereas in the group of patients who received a metal-backed tibial component, the score improved from 35 to 85 points. Functional scores increased from preoperative values of 56 to 74 points in the patients who received all-polyethylene tibial components, and 57 to 72 points in the patients who received metal-backed tibial components. Range of motion measured at latest followup averaged 106 degrees in patients who received an all-polyethylene tibial component and 107 degrees in the patients who received a metal-backed component, and postoperative tibiofemoral alignment averaged 6 degrees valgus for both groups. There were 13 reoperations for instability, patellofemoral problems, or deep infection, but none for aseptic loosening or wear in either group. These differences were not statistically significant, nor were any measures of patient satisfaction or clinical outcome between the two groups in this period. Total knee arthroplasty with a well-designed, contemporary congruent all-polyethylene tibial component functions equivalently to its metal-backed tibial counterpart at 3- to 5-year followup in this patient population, and is less costly ($675).     

Clinical results of isolated tibial component revisions with femoral component retention

The purpose of this study is to report the outcome for a consecutive series of isolated nonmodular tibial component revisions. A consecutive series of 6548 total knee arthroplasties (6024 metal backed; 524 all-polyethylene) were performed with nonmodular tibial components of which 54 knees (0.82%) (22 metal backed; 32 all-polyethylene) underwent isolated tibial component revision with femoral component retention. Clinical outcome and component survivorship were examined. Pain scores improved from 19 to 42 points and Knee Society score improved from 62 to 87 points after revision. At a mean of 6.6-year follow-up, the survivorship of the revised tibial components and retained femoral components, with aseptic loosening as the end point, was 100%.     

Midterm results of all-polyethylene tibial components in primary total knee arthroplasty

Our goal was to determine the 7-year survivorship of a total knee arthroplasty system with all-polyethylene tibial components. From June 1996 to December 1997, 129 consecutive patients (177 knees) (>/=70 years old) underwent such primary arthroplasty at 2 centers in the United States. The 88 patients (120 knees) with 7 years or more of follow-up were evaluated radiographically and functionally. Average results included: Knee Society Score, 93.7 points (SD, 8.1); Knee Society function score, 68.9 points (SD, 27.6); range of motion, 119 degrees (SD, 10.9); osteolysis, 0%; stress shielding, 6.6%; progressive radiolucencies, 2.5%; Kaplan-Meier survivorship (revision), 99.4% (95% confidence intervals, 98.2%-100.0%). At midterm follow-up, an all-polyethylene tibial component proved to be an excellent surgical option for total knee arthroplasty in an elderly patient population.     

Eleven-year implant survival rates of the all-polyethylene and metal-backed modular Optetrak posterior stabilized knee in bilateral simultaneous cases

A prospective randomized study was conducted to determine if a design change in the articular surface geometry introduced in the Optetrak total knee to increase prosthetic joint conformity and further reduce polyethylene stress had any impact on implant survival, particularly when the all-polyethylene version of the implant was used. Forty-seven patients undergoing bilateral simultaneous total knee arthroplasties were randomized for the side, receiving an all-polyethylene tibial component and followed up for a mean 11.6 years. Survival rates for the all-polyethylene and metal-backed modular versions of the implant were both 98%, excluding a single case of deep infection. Survival rates with revision for aseptic loosening as an end point were 100%. The increase in tibial and femoral radii in the coronal plane of the Optetrak posterior stabilized knee did not result in a reduced implant survival rate in either the metal-backed modular or all-polyethylene versions of the implant.     

Migration of all-polyethylene compared with metal-backed tibial components in cemented total knee arthroplasty

Background and purpose — With a rapidly increasing population in need of total knee arthroplasty (TKA), there is renewed interest in cost-saving all-polyethylene designs. Differences between metal-backed and all-polyethylene designs in initial component migration assessed by radiostereometric analysis (RSA), a proven predictor for late aseptic loosening, have been scantily reported. The purpose of this study was to compare implant migration and clinical outcomes of all-polyethylene tibial components versus metal-backed trays of similar geometrical shape.

Patients and methods — In this randomized controlled trial, 59 patients received a cemented Triathlon condylar-stabilizing implant (Stryker, Mahwah, NJ, USA) with either an all-polyethylene (n = 29) or a metal-backed tibial component (n = 30). RSA measurements and clinical scores (the Knee Society Score, Forgotten Joint Score, and Knee Osteoarthritis and Injury Outcome Score) were evaluated at baseline and postoperatively at 3, 12, and 24 months. A linear mixed-effects model was used to analyze the repeated measurements.

Results — A statistically significant difference in mean migration after 2 years was found in favor of the all-polyethylene group, with a mean maximum total point motion of 0.61?mm (95% CI 0.49–0.74) versus 0.81?mm (95% CI 0.68–0.96) for the cemented group (p = 0.03). However, this difference was smaller and not statistically significant after post hoc adjustment for surgeon effect. Both groups showed comparable improvements on all clinical outcome scores over time.

Interpretation — The Triathlon all-polyethylene tibial component showed less migration, suggesting a lower risk of late loosening as compared with its metal-backed counterpart. However, the found surgeon effect warrants further investigation.     

Superior Survival of Fully Cemented Fixation Compared to Hybrid Fixation in a Single Design Rotating Hinge Knee Implant

BackgroundClinical observations revealed higher rates of aseptic loosening for hybrid fixated rotating hinge knee implants compared to fully cemented ones. We hypothesize that the use of a fully cemented fixation technique had a higher survival rate for aseptic loosening compared to a hybrid fixation technique in a rotating hinge knee implant.MethodsAll procedures of patients who were treated with the RT-PLUS rotating hinge knee implant (Smith & Nephew, Memphis, TN) between 2010 and 2018 were included. Primary outcome was revision for aseptic loosening. Kaplan-Meier survivorship and Cox proportional hazard regression analysis were performed to calculate survival rates and hazard ratios.ResultsA total of 275 hinge knee implants were placed in 269 patients (60 primary procedures, 215 revisions). Median follow-up was 7.3 ± 3.9 years. In total, 24 components (16 hybrid femur, 2 fully cemented femur, 6 hybrid tibia; all revision procedures) in 19 patients were revised for aseptic loosening. Kaplan-Meier survivorship analysis showed superior survival rates of fully cemented components (femur 97.1%; tibia 100%) compared to hybrid fixated components (femur 89.5%; tibia 95.9%) at the 10-year follow-up. Multivariate Cox hazard analysis showed a significantly higher risk of aseptic loosening for hybrid fixated components, a prior stemmed component and the femoral component.ConclusionFully cemented fixation showed superior survival rates for aseptic loosening compared to hybrid fixation in a single design rotating hinge knee implant. A prior stemmed component appears to be a risk factor for aseptic loosening and the femoral component seems to be more prone to loosening.     

Metal-backed and all-polyethylene tibial components in total knee replacement.

One hundred seventy-five patients with 243 consecutive primary Press Fit Condylar cruciate-substituting total knee replacements were evaluated at a mean of 5.5 years. One hundred thirteen knees had modular metal-backed tibial components and 130 had all-polyethylene tibial components. The mean knee score and functional score for the patients with unrevised components was not significantly different. The incidence of osteolysis and synovitis was higher in patients in the modular metal-backed tibia group (5%; five patients, six knees). No patients in the all-polyethylene tibia group had osteolysis or synovitis. Five revision operations were necessary: four for osteolytic defects and one for synovitis, all in patients in the modular metal-backed tibia group. All of the retrieved polyethylene inserts had evident backside wear. The best case rate of survival of the all-polyethylene tibial components was 96%+/-0.8% at 7 years and for the modular metal-backed components it was 75%+/-10% at 7 years. Metal backing and modularity were added to the Press Fit Condylar total knee replacement design to improve fixation durability. However, the superiority of the modular metal-backed implants remains in question.     

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.     

Midterm Results After Tantalum Cones in 1-Stage Knee Exchange for Periprosthetic Joint Infection: A Single-Center Study

BackgroundThe use of tantalum cones to reconstruct extensive bone defects in revision total knee arthroplasty has been established. We aimed to evaluate the midterm results after 1-stage knee exchange for periprosthetic joint infection using tantalum cones.MethodsSeventy-two patients (mean age, 70 ± 8.2 years) treated with a 1-stage exchange for infected total knee arthroplasty using porous tantalum cones, between 2011 and 2016, were retrospectively included. Either rotating or pure hinge system in combination with femoral and/or tibial cones was used. Survivorship analysis (septic and aseptic) was performed. Prospectively, functional outcome was assessed at a mean follow-up of 49.9 ± 18.8 months (range, 24-88).ResultsA total of 15 patients (21%) were rerevised, 8 (11.1%) for infection and 7 (10%) for aseptic loosening, requiring cone exchange in 12 patients (17%). Cone-related survival free from any revision was 83% ± 3.8 standard deviation (95% confidence interval, 74-90), and infection-free survival was 89% ± 4.2 standard deviation (95% confidence interval, 76-93). No significant correlation was reported between the types of prosthesis used (P = .8) or implanted cones and failure (P = .6). History of a previous septic revision increased the risk of cone revision after the index surgery (P < .001). Preoperative Hospital for Special Surgery knee score improved from 47 ± 16 (range, 14-87) to 60 ± 17 (range, 24-84) points at the latest follow-up.ConclusionFirst study reports on outcomes of the 1-stage exchange using tantalum cones for knee periprosthetic joint infection with additional severe bone loss. Midterm cone-related and infection-free survival offered good results and provided reasonable functional outcomes.     

Eighteen-Year Outcome of an Uncemented "Meniscal Bearing", Cruciate-Retaining Total Knee System

BackgroundThe aim of this study is to evaluate the survival, radiographic, and functional outcomes of the uncemented “meniscal bearing” cruciate-retaining Low Contact Stress (LCS) (DePuy Synthes, Warsaw, IN, USA) total knee system after a long-term follow-up period.MethodsA total of 56 patients (67 knees) who received an uncemented “meniscal bearing” cruciate-retaining LCS total knee system between 2000 and 2005 were retrospectively reviewed. Patients were 64 ± 7 years old with osteoarthritis as the indication for arthroplasty. The survivorship, radiographs, and patient-reported outcome measures (PROMs) were analyzed.ResultsThe all-cause survival after 5, 10, 15, and 18 years was 97.0%, 93.8%, 92.0%, and 92.0%, respectively. Survival with revision for aseptic loosening as an end point was 98.4% at 5 years and 96.7% at 10, 15, and 18 years. Reasons of revisions and their interventions consisted of anterior knee pain requiring secondary patellar resurfacing (n = 3, 60%), polyethylene wear requiring an insert exchange (n = 2, 40%), and bearing spin-out requiring an insert exchange (n = 1, 20%). Two of the 5 revision cases developed aseptic loosening of the tibial component later on during the study period. A radiographic analysis demonstrated radiolucent lines in 14/47 implants (30%) after 12.0 ± 3.8 years, but were not revised, respectively. After a mean follow-up of 18.5 years, PROMs (n = 20) were found comparable with the 1-year postoperative PROMs of all implants reported by the LROI (Dutch Arthroplasty Register).ConclusionThis present study demonstrates good results of the uncemented “meniscal bearing” cruciate-retaining LCS total knee system toward survival and functional outcomes after a long-term median follow-up of 17.5 years.Level of EvidenceTherapeutic retrospective cohort study, LEVEL III.     

Advantage of Minimal Anterior Knee Pain and Long-term Survivorship of Cemented Single Radius Posterior-Stabilized Total Knee Arthroplasty without Patella Resurfacing

BackgroundThe single radius total knee prosthesis was introduced with the advantage of reduced patellar symptoms; however, there is no long-term follow-up study of the same. The purpose of this study was to determine the survival rate of single radius posterior-stabilized total knee arthroplasty and patellofemoral complication rates in a consecutive series.MethodsSeventy-one patients (103 knees) who underwent arthroplasty without patellar resurfacing using a single radius posterior-stabilized total knee prosthesis were followed up for a minimum 10 years. Clinical evaluation using Knee Society knee and function scores and radiologic evaluation were performed at regular intervals. Anterior knee pain as well as patellofemoral complications were evaluated with a simple questionnaire. The Kaplan-Meier product-limit method was used to estimate survival.ResultsSeventeen patients (23 knees) were excluded due to death (12 knees) or lost to follow-up (11 knees). Of the 80 knees enrolled, all femoral components and 78 tibial components were well fixed without loosening at final follow-up. Two revisions were performed because of tibial component loosening and periprosthetic joint infection. One patient with tibial component loosening refused to have revision surgery. No obvious tibial insert polyethylene wear was observed. The survivorships at 132 months were 96.7% using revision or pending revision as end points. Anterior knee pain was present in 6 patients (6 knees, 7.5%) at the latest follow-up. No patellofemoral complication requiring revision was encountered.ConclusionsThe single radius posterior-stabilized total knee prosthesis demonstrated an excellent minimum 10-year survivorship. The low rates of implant loosening and 7.5% of anterior knee pain as a patellofemoral complication are comparable with those reported for other modern total knee prosthesis.     

Long-term results of total condylar knee arthroplasty

From 1979 to 1984, 126 consecutive Total Condylar (Howmedica, Rutherford, NJ) knee arthroplasties were performed at a hospital in Taiwan, of which 64 knees were available for evaluation. The patients' average weight was 58 kg. The average Hospital for Special Surgery knee score at the latest follow-up was 86 points. Using revision for mechanical failure as an end point, the 20-year overall survival was 91.9%. The survival for the all-polyethylene tibial component was 96.4% and for the metal-backed tibial component was 88.4%. The difference was statistically significant (P < .001). We recommend the use of the more cost-effective and durable all-polyethylene tibial component for a primary cemented total knee arthroplasty, particularly in Asians with a relatively low weight and who are relatively inactive, especially in elderly people.     

Comparison of metal-backed and all-polyethylene tibial components in cruciate condylar total knee arthroplasty

An evaluation of 78 knees in 63 patients using the cruciate-sparing total condylar prosthesis was performed. At a mean of 10 years following the arthroplasty there were 86% good or excellent results in knees with an all-polyethylene tibial component compared to 95% with a metal-backed tibial component (NS). Survivorship at 10 years using an endpoint of revision was 96% (NS) in both groups; using an endpoint of revision or poor knee score was 85% (NS) in the metal-backed compared to 92% (NS) in the all-polyethylene groups; using an endpoint of revision, poor knee score, or complete radiolucent line was 85% in the metal-backed compared to 90% (NS) in the all-polyethylene groups. There were no significant differences in the frequency of radiolucent lines at the last evaluation. Two percent of the tibial components in the metal-backed group had complete radiolucent lines compared to none in the allpolyethylene group. The cruciate-sparing total condylar prosthesis provides satisfactory results with no significant differences between the metal-backed or all-polyethylene tibial components at 10 years.     

A Prophylactic Tibial Stem Reduces Rates of Early Aseptic Loosening in Patients with Severe Preoperative Varus Deformity in Primary Total Knee Arthroplasty

BackgroundPatients with a preoperative varus deformity >8 degrees are at increased risk of aseptic loosening after total knee arthroplasty. This study analyzes the effect of a tibial stem on the rate of aseptic loosening in patients with a severe preoperative varus deformity.MethodsPatients with a preoperative varus deformity of >8 degrees and 2-year minimum follow-up with a stemmed tibial component (n = 67) were matched 1:2 to patients with a similar preoperative varus deformity with a standard tibial component (n = 134). Radiolucent lines were measured on the tibia at 6 weeks, 1 year, and 2 years postoperatively using the Knee Society Radiographic Evaluation System. Failure was defined as revision due to aseptic loosening of the tibial component. Outcomes were evaluated using Student’s t-tests and log-rank tests.ResultsPatients with tibial stems had greater preoperative deformity (12.9 vs 11.3 degrees, P = .004). There was no difference in postoperative alignment (1.7 vs 2.1 degrees varus, P = .25) or tibial component angle (1.8 vs 2.1 degrees varus, P = .33). Patients with stems were more likely to have more constraint (44.8% vs 1.5%, P < .001). Progression of radiolucent lines >2 mm was observed in 17.6% (23/134) vs 5.97% (4/67) of patients in the stem group (P = .03). Rates of aseptic loosening were lower in the stem group (0% vs 5.15%, P = .05).ConclusionDespite worse preoperative deformity and higher utilization of constraint, tibial stem use in patients with severe preoperative varus deformity resulted in lower rates of aseptic loosening. Prophylactic use of stems in these patients may help increase implant survival.     

Dual massive skeletal allograft in revision total knee arthroplasty

The reconstruction of large uncontained defects represents a major challenge to the revision total knee surgeon, and the outcome of the revision often depends on the management of these bone deficiencies. We report the first successful use of both complete distal femoral and proximal tibia massive allografts in the reconstruction of large femoral and tibial uncontained defects during revision total knee arthroplasty. At the five-year follow up, we did not find any infection, graft failure or loosening of implant, in spite of using two massive structural allografts in a single revision total knee arthroplasty.