Cemented total knee arthroplasty remains the “gold standard”

Despite its availability for several decades, current literature does not provide sufficient evidence to demonstrate superiority of cementless total knee arthroplasty (TKA) when compared to cemented TKA. This review aims to highlight the current disadvantages and shortcomings of cementless fixation for TKA.     

The cementless knee: Intermediate term guarantee on parts and labor

While cemented fixation is the current gold standard in North America, biologic fixation to host bone has the potential for a more durable construct, particularly in young and active patients. Previous failures with cementless TKA constructs have been attributed to design-related issues such as poor tibial ingrowth surfaces, metal-backed patellas, screw track osteolysis, and issues with the polyethylene, including thin inserts and non-conforming articulations. Recent innovations such as tantalum have shown durable and reliable results with contemporary cementless TKAs. Additional advantages include diminished operative times, preservation of bone stock, ease of revision surgery, and elimination of third body wear.     

The Future is Non-cemented Total Knee Arthroplasty: Volume Trends at the Hospital for Special Surgery

IntroductionThe optimal fixation method for total knee arthroplasty (TKA) is still a debate. Cemented fixation has excellent long-term results and is the gold standard. However, longevity in the younger, heavier, and more active population is suboptimal. Cementless TKA offers the opportunity to gain biological fixation and overcome these shortcomings.MethodsThis is a retrospective review of all consecutive cementless TKA procedures performed at a single academic institution from 2016 until 2020. Demographics, aseptic revisions, and septic revisions were pulled from the electronic medical record. The number of yearly implanted cementless TKA prosthesis was determined to analyze utilization trends.ResultsEight-hundred and two patients were identified with a mean age of 61.57 ± 7.78 years, and a mean of BMI 32.12 ± 5.98 kg/m². The mean time to revision was 12.31 ± 13.91 months. There were four septic failures and nine aseptic failures during the study period. Of these nine aseptic failures only five were due to mechanical loosening. There was a yearly linear increase in the use of cementless fixation.ConclusionCementless fixation is here to stay, and its use will continue to increase. Early and mid-term outcomes have been excellent thus far. Changing clinical practice takes time but we have already seen this transition take place in total hip arthroplasty. As technology and design continue to evolve, we believe it is a possibility.     

使用与不用骨水泥固定人工膝关节置换术后疗效的比较

探讨使用与不用骨水泥固定氧化铝陶瓷制NCU型TKA术后的疗效。1989～1995年,为了治疗晚期骨性关节病及类风湿病,共施行NCU型TKA68例103个关节。对获得平均随访5年8个月的65例99个关节的以胫骨假体为中心的临床评价及X线计测的结果进行了比较性分析。临床评价方法是以JOA膝关节评价基准为标准,X线的评价方法是将术前、术后、最终调查时的正侧位X线照片数字化后输入电子计算机利用电脑软件系统进行了计测与评价。65例99个关节TKA术后经随访5年以上的结果表明NCU型TKA术后获得了比较良好的疗效。术后并发症7％,再手术率5％,不用骨水泥组疗效劣于使用骨水泥固定组,两组间的疼痛评分及透亮线出现率的差异均有显著性统计学意义。     

Increased Survivorship of Cementless versus Cemented TKA in the Morbidly Obese. A Minimum 5-Year Follow-Up

Background

Total knee arthroplasty (TKA) in the morbidly obese patients can be challenging with an increased risk of complications. Studies have shown increased aseptic failures with well-aligned cemented TKAs in the obese patient. The purpose of this study is to determine if TKA in the morbidly obese (body mass index [BMI] ≥ 40) using cementless implants would demonstrate improved results and survivorship compared to cemented TKA at a minimum 5-year follow-up.

Hybrid component fixation in total knee arthroplasty: minimum of 10-year follow-up study

Hybrid total knee arthroplasty (TKA) (uncemented femur with cemented tibia and patella) was introduced in the late 1980s to gain the theoretical advantage of durable cementless femoral fixation while avoiding the problems noted with cementless tibial fixation. From December 1992 to July 2000, 215 patients (235 knees) who underwent hybrid TKA were enrolled in this study. Five types of prosthesis (AGC, Maxim, LCS-M, LCS-APG, and Scorpio) were used. Revision rate for aseptic loosening was 16 (6.8%) of 235 knees. At 10 and 15 years, survivorship with tibial or femoral revision as the end point was 0.95 and 0.92, respectively. Hybrid TKA provides durable fixation with clinical and radiographic performance at minimum 10 years comparable with cemented series.     

Does Body Mass Index Influence the Outcomes and Survivorship of Modern Cementless Total Knee Arthroplasty?

BackgroundHigher body mass index (BMI) has been associated with higher rates of aseptic loosening following cemented total knee arthroplasty (TKA). However, there is a paucity of evidence on the effect of BMI on the durability of modern cementless TKA. We aimed to assess the association between BMI and clinical outcomes following cementless TKA and to determine if there was a BMI threshold beyond which the risk of revision significantly increased.MethodsWe identified 1,408 cementless TKAs of a modern design from an institutional registry. Patients were classified into BMI categories: normal (n = 136), overweight (n = 476), obese class I (n = 423), II (n = 258), and III (n = 115). The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement and 12-item Short Form Health Survey scores were collected preoperatively and 2 years postoperatively. Survivorship was recorded at minimum 2 years (range, 24 to 88 months). BMI was analyzed as a continuous and categorical variable.ResultsThe improvement in patient-reported outcomes was similar across the groups. Thirty four knees (2.4%) were revised and 14 (1.0%) were for aseptic failure. Mean time-to-revision was 1.2 ± 1.3 years and did not differ across BMI categories (P = .455). Survivorship free from all-cause and aseptic revision was 97.1% and 99.0% at mean 4 years, respectively. Using Cox regression to control for demographics and bilateral procedures, BMI had no association with all-cause revision (P = .612) or aseptic revision (P = .186). Receiver operating characteristic curve analysis found no relationship between BMI and revision risk (c-statistic = 0.51).ConclusionBMI did not influence functional outcomes and survivorship of modern cementless TKA, possibly due to improved biological fixation at the bone-implant interface. Longer follow-up is necessary to confirm these findings.     

Redefining Indications for Modern Cementless Total Knee Arthroplasty: Clinical Outcomes and Survivorship in Patients >75 Years Old

BackgroundMost studies on cementless total knee arthroplasty (TKA) have excluded patients >75 years due to concerns that older patients have poorer bone mineral density and osteogenic activity. This study compared the midterm outcomes and survivorship of cemented and cementless TKA of the same modern design performed in patients >75 years.MethodsWe identified a consecutive series of 120 primary cementless TKA performed in patients >75 years. Each case was propensity score matched 1:3 with 360 cemented TKA of the same modern design based on age, sex, body mass index, Charlson Comorbidity Index, bilateral procedures, liner type, and year of surgery. Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) and Short Form-12 (SF-12) were collected preoperatively, at 6 months and 2 years. Implant survivorship was recorded at mean 4.2 years (range, 2.0-7.9).ResultsMean age was 79.0 ± 3.4 years (range, 75-92) in the cemented cohort and 78.9 ± 3.5 (range, 75-91) in the cementless cohort (P = .769). There was no difference in final postoperative scores or improvement in scores at 2 years. The percentage of patients that met the minimal clinically important difference was also similar (KOOS-JR, 68.9% vs 69.2%, P = .955; SF-12 Physical, 71.7% vs 66.7%, P = .299). Seven-year survivorship free from aseptic revision was 99.4% for cemented knees and 100% for cementless knees (log-rank, P = .453).ConclusionPatients over 75 years undergoing cementless or cemented TKA of the same modern design had comparable outcomes and survivorship in the midterm. The theoretical risks of cementless fixation in this age group were not realized in this study.     

Results of cementless total knee arthroplasty in an older rheumatoid arthritis population

Fifty-five total knee arthroplasties (TKAs) in thirty-nine adult (mean age, 62 years) patients with rheumatoid arthritis were studied prospectively for a period of 1-7 years. All of the procedures were performed using cementless fixation of the tibial and femoral components. The Knee Society clinical rating system mean knee scores increased 56 points after operation (mean, 88 points), and the mean functional scores increased 28 points (mean, 64 points). Two revisions (4%) have been required, one for secondary late infection and one for failure of a cementless metal-backed patellar component. Good bone stock was retained in both, allowing for uneventful cementless revision. Forty-two arthroplasties (76%) were completely pain-free, twelve (22%) had mild, occasional discomfort with weight-bearing, and one (2%) had moderate pain at last examination. In this older rheumatoid population, cementless TKA offers good or excellent early clinical results and excellent preservation of bone stock should revision become necessary.     

Cementless vs Cemented Tibial Fixation in Primary Total Knee Arthroplasty

Background

The ideal fixation for modern tibial components in total knee arthroplasty (TKA) remains controversial with uncertainty on whether cementless implants can yield equivalent outcomes to cemented fixation in early follow-up.

Survivorship of Metaphyseal Sleeves in Revision Total Knee Arthroplasty

Background

Metaphyseal fixation has promising early results in providing component stability and fixation in revision total knee arthroplasty (TKA). However, there are limited studies on midterm results of metaphyseal sleeves. We analyzed complications, rerevisions, and survivorship free of revision for aseptic loosening of metaphyseal sleeves in revision TKA.

The Use of Cementless Components Does Not Significantly Increase Procedural Costs in Total Knee Arthroplasty

BackgroundModern cementless total knee arthroplasty (TKA) designs have shown promising early clinical success; however, concerns exist regarding the higher cost of the cementless implants. The purpose of this study is to evaluate the total facility cost of cementless vs traditional cemented TKA along with the effect of cementless fixation on short-term outcomes.MethodsWe reviewed a consecutive series of patients between 2015 and 2017 who underwent either cementless or cemented primary TKA. Itemized facility costs were calculated for every procedure using a time-driven activity-based costing algorithm. Controlling for demographic variables and medical comorbidities, we performed a multivariate analysis to identify independent risk factors for facility costs following TKA. Short-term outcome metrics including complications, readmissions, and patient-reported outcomes were compared between groups.ResultsAmong the 2426 primary TKA patients in this study, 119 (4.91%) were performed using cementless implants. When compared to cemented TKA, cementless TKA patients had higher implant costs ($3047.80 vs $2808.73, P < .0001), but lower supply costs ($639.49 vs $815.57, P < .0001) and lower operating room personnel costs ($982.01 vs $1238.26, P < .0001). When controlling for confounding variables, cementless fixation did not have a significant effect on total facility cost or outcomes.ConclusionIn conclusion, the use of cementless TKA implants did not significantly increase total procedural costs when compared to traditional cemented TKA components at our institution. Our data suggest that the increased cost of a cementless implant is recouped through savings in cost of cement and supplies, as well as shorter operative times. The authors encourage investigators at other institutions to use the authors' methodology to evaluate (preferably in a prospective manner) whether the findings from this study can be corroborated.     

骨水泥与非骨水泥固定在初次全膝关节置换术中的应用:系统评价和meta分析

背景:全膝关节置换术(TKA)治疗终末期膝关节疾病的效果已被公认。目前TKA中假体-骨的固定形式主要有骨水泥固定和非骨水泥固定两种;前者应用广泛,但理想的假体固定方法仍存在争议。目的:通过meta分析评价骨水泥或非骨水泥固定在初次TKA中的优缺点,探讨其不同的适应证并提出TKA的最佳固定方式。方法:通过检索策略检索PubMed、The Cochrane Library、EMbase、CNKI、VIP、CBM和万方数据库,收集所有TKA术中骨水泥和非骨水泥固定的报道,采用RevMan 5.1软件进行meta分析。结果:最终纳入17项研究,并对其报道的结局指标进行合并分析。其中9项研究报道了TKA术后5年内的膝关节假体生存率,发现骨水泥固定组与非骨水泥固定组间生存率有显著统计学差异(RR=1.02,95%CI:1.00~1.05,P=0.02),但5年后的膝关节假体生存率无统计学差异(RR=1.01,95%CI:0.97~1.04,P=0.75)。术后假体相关并发症,骨水泥与非骨水泥固定组间无显著统计学差异(RR=0.97,95%CI:0.75~1.27,P=0.84)。影像学指标:术后两组间胫骨组件位置在冠状位及矢状位上偏移度数存在统计学差异,其他指标无统计学意义。结论:非骨水泥固定TKA植入组件发生偏转的概率相对较高,但非骨水泥固定TKA在假体中期生存率和临床疗效方面与骨水泥固定结果相似。为了更全面、准确地评价骨水泥固定与非骨水泥固定的长期生存率、安全性、临床及放射学指标,还需进一步研究。     

Cemented Versus Cementless Total Knee Arthroplasty in Obese Patients With Body Mass Index ≥35 kg/m2: A Contemporary Analysis of 812 Patients

BackgroundCemented total knee arthroplasty (TKA) has been shown to have higher failure rates in obese patients, and cementless TKA may provide more durable fixation. This study compared outcomes and survivorship of obese patients undergoing cemented and cementless TKA of the same modern design.MethodsWe identified a consecutive series of 406 primary cementless TKA performed in obese patients with body mass index (BMI) ≥35 kg/m² in 2013-2018. Each case was matched 1:1 with 406 cemented TKA based on age, sex, BMI, bearing surface, and year of surgery. Knee Injury and Osteoarthritis Outcome Score for Joint Replacement and Short Form-12 were collected preoperatively, at 6 months and 2 years. Implant survivorship was recorded at mean 4.0 years (range 2.0-7.8).ResultsThere was no difference in mean BMI between the cemented (38.6 ± 3.4 kg/m²; range, 35-60) and cementless cohorts (38.7 ± 3.3 kg/m²; range, 35-54; P = .706). Both groups had similar final postoperative scores and improvement in scores at 2 years. Furthermore, a similar percentage met the minimal clinically important difference (Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, 70.0% vs 71.2%, P = .700; Short Form-12 Physical, 74.1% vs 70.4%, P = .240). Both groups demonstrated high 7-year survivorship free from aseptic revision (99.0% vs 99.5%, P = .665).ConclusionObese patients with BMI ≥35 kg/m² undergoing cementless and cemented TKA of the same modern design had similar outcomes and survivorship at early to mid-term follow-up. Continued surveillance of this high-risk population is necessary.     

Manipulation Under Anesthesia is Safe After Cementless Total Knee Arthroplasty: A Multicenter Study

BackgroundCementless total knee arthroplasty (TKA) is thought to facilitate durable, biological fixation between the bone and implant. However, the 4-12 weeks required for osseointegration coincides with the optimal timeframe to perform a manipulation under anesthesia (MUA) if a patient develops postoperative stiffness. This study aims to determine the impact of early MUA on cementless fixation by comparing functional outcomes and survivorship of cementless and cemented TKAs.MethodsA consecutive series of patients who underwent MUA for postoperative stiffness within 90 days of primary, unilateral TKA at 2 academic institutions between 2014 and 2018 were identified. Cases involving extensive hardware removal were excluded. Cementless TKAs undergoing MUA (n = 100) were propensity matched 1:1 to cemented TKAs undergoing MUA (n = 100) using age, gender, body mass index, and year of surgery. Both groups had comparable baseline Knee Injury and Osteoarthritis Outcome Scores (KOOS), Short Form (SF)-12 Physical, and SF-12 Mental scores. MUA-related complications as well as postoperative KOOS and SF-12 scores were compared.ResultsMUA-related complications were equivalently low in both groups (P = .324), with only 1 patella component dissociation in the cementless group. No tibial or femoral components acutely loosened in the perioperative period. Postoperative KOOS (P = .101) and SF-12 Mental scores (P = .380) were similar between groups. Six-year survivorship free from any revision after MUA was 98.0% in both groups (P = 1.000).ConclusionEarly postoperative MUA after cementless TKA was not associated with increased MUA-related complications or worse patient-reported outcomes compared to cemented TKA. Short-term survivorship was also comparable, suggesting high durability of the bone-implant interface.     

Clinical Outcomes of Revision Total Knee Arthroplasty after High Tibial Osteotomy and Unicompartmental Knee Arthroplasty: A Systematic Review and Meta‐Analysis

As more high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are performed, orthopaedic surgeons realize that more HTO and UKA failures will require revision to total knee arthroplasty (TKA) in the future. To systematically evaluate the clinical outcomes of TKA after HTO and TKA after UKA, the Embase, PubMed, Ovid, Web of Science, and Cochrane Library databases were searched for studies investigating revision TKA after HTO and UKA published up to June 2021. RevMan version 5.3 was used to perform the meta‐analysis. The revision TKA after HTO and revision TKA after UKA groups were compared in terms of operative time, range of motion (ROM), knee score, postoperative complications, postoperative infection, revision, and revision implants used. Nine studies were ultimately included in the meta‐analysis. Results revealed that the knee score for the revision TKA after HTO group was better than that of the revision TKA after UKA group (MD 4.50 [95% CI 0.80–8.20]; p = 0.02). The revision TKA after HTO group had a lower revision rate (OR 0.65 [95% CI 0.55–0.78]; p < 0.00001) and fewer revision implants used (OR 0.11 [95% CI 0.05–0.23]; p < 0.00001). There were no statistical differences in operation time (MD ‐2.00 [95% CI −11.22 to 7.21]; p = 0.67), ROM (MD ‐0.04 [95% CI ‐3.69–3.61]; p = 0.98), postoperative complications (OR 1.41 [95% CI 0.77–2.60]; p = 0.27), or postoperative infections (OR 0.89 [95% CI 0.61–1.29]; p = 0.53). To conclude, the revision rate of revision TKA after UKA was greater, and more revision implants were required. It is important for orthopaedic surgeons to preserve bone during primary UKA.     

Long-term Survival Rate of Implants and Modes of Failure After Revision Total Knee Arthroplasty by a Single Surgeon

The purpose of the present study was to analyze the survival rate of implants and mode of failure after revision total knee arthroplasty (TKA) using one type of modular prosthesis by a single surgeon. From September 1990 to June 2009, 224 revision TKAs were performed in 194 patients. The 5-, 8-, and 10-year survival rates were 97.2%, 91.6%, and 86.1%, respectively. Re-revision TKAs were performed in 20 knees because of infection (seven knees), loosening (six knees), polyethylene wear (six knees), and periprosthetic fractures (one knee). The long-term survival rate of revision TKA was satisfactory, but careful attention is necessary to detect the late failure. The prevention of infection and the stable fixation of components are required at the time of revision TKA.     

Cementless TKA: The preferred method for young,active, and heavy patients

Cementless fixation has the advantage of obtaining biological fixation, which should respond better than cement to the increased stresses that are expected in younger, active, and/or obese patients. In total, 1011 Natural-Knee® cementless total knee replacements were performed by the author from 1986 to 2015 in this patient population. The 10-year failure rates of 20–30% were noted in the early cases, which included the use of metal-backed patellae and use of tibial screws that allowed back-side polyethylene wear debris-induced osteolysis. Reliable bone attachment occurred. The last 760 total knee replacements in this series have been performed with cementless femoral and tibial components, no tibial screws, cemented patellae, and highly cross-linked polyethylene tibia with only one revision for aseptic loosening or osteolysis.     

Tantalum Cones for Severe Bone Defects in Revision Knee Arthroplasty: A Minimum 10-Year Follow-Up

BackgroundTwo-to 6-year results of reconstruction of severe bone defects in revision total knee arthroplasty (TKA) with highly porous tantalum cones have been encouraging, but 10-year follow-up is lacking. The purpose of this study was to determine the minimum 10-year results of tantalum cones in revision TKA.MethodsFrom 2005 to 2010, 30 consecutive patients (30 knees) underwent revision TKA with the use of cones. All patients were followed clinically and radiographically for a minimum of 10 years. A total of 42 cones (25 tibial and 17 femoral) were used to reconstruct massive bone defects classified as Anderson Orthopaedic Research Institute Types 2A (10), 2B (12), and 3 (19). The mean age of the patients was 73 years (range, 55 to 84) at the time of revision. The indication for the revision included aseptic loosening (15 patients) and second-stage reimplantation for deep infection (15 patients). Six patients were lost to follow-up.ResultsIn total, 6 cones had to be revised. Minimum 10-year cone survivorship for any reason was 81% (25 of 31 cones). With cone revision for aseptic loosening as the end point, survivorship was 96% (30 of 31). No evidence of loosening or migration of any implant was noted on the most recent radiographs.ConclusionMetaphyseal fixation with tantalum cones in revision TKA demonstrated excellent survivorship and fixation at a minimum follow-up of 10 years. This type of metaphyseal reconstruction can be a durable option for revision TKA in patients who have massive bone defects.     

Use of Stepped Porous Titanium Metaphyseal Sleeves for Tibial Defects in Revision Total Knee Arthroplasty: Short Term Results

Stepped porous titanium metaphyseal sleeves may provide an option for enhanced fixation in managing challenging tibial defects in revision total knee arthroplasty (TKA). We retrospectively reviewed data on 51 patients who underwent revision TKA utilizing a metaphyseal sleeve for Anderson Orthopaedic Research Institute (AORI) Type II and III tibial defects between June 2007 and July 2011. Of these 51 patients, 36 patients had complete clinical and radiographic data. At final follow-up (mean: 38 months) significant improvements in knee range of motion and Knee Society scores were observed postoperatively (P < 0.001). Four revision procedures were necessary, but none for aseptic implant fixation failure. Radiographic review at final follow-up revealed stable, osteointegrated components without component migration or clinically significant osteolysis. Metaphyseal sleeve use in the management of moderate to severe tibial defects in revision TKA resulted in satisfactory clinical outcomes and is a versatile option for achieving stable fixation.