Cemented versus cementless fixation of a tibial component in LCS mobile-bearing total knee arthroplasty performed by a single surgeon

Enhanced improvement and comparable survivorship in cementless versus cemented total knee arthroplasty: a 2-year analysis of patient reported outcomes and 5-year analysis of implant survivorship

PURPOSE

This study aimed to evaluate patient-reported outcomes, functional recovery, satisfaction, and implant survivorship for cementless and cemented TKA.

METHODS

A prospective, non-randomized, multicenter study was conducted on 453 patients. Cohort 1 (n = 373 knees) received a fully cementless construct with the Triathlon Tritanium Tibial Baseplate, Triathlon Tritanium Patella, Triathlon CR or PS Beaded Femur with Peri-Apatite, and the Triathlon Tibial Insert. Cohort 2 (n = 147 knees) received a fully cemented construct with identical implant design. Oxford Knee Score (OKS), 2011 Knee Society Score (KSS), and Short Form 12 scores were recorded preoperatively and at 6 weeks, 6 months, 1 year, and 2 years postoperatively. Implant survivorship and adverse events were also recorded.

RESULTS

OKS (mean difference [MD] 1.5, p = 0.0123), KSS Symptoms for pain (with level walking [MD 0.62, p = 0.0007]; with stairs or incline [MD 0.85, p = 0.0037), KSS Patient satisfaction (MD 2.31, p = 0.0004), and KSS Functional Activities (MD 0.53, p = 0.0108) were significantly greater in Cohort 1 out to 2 years postoperatively. The Kaplan-Meier estimated all-cause survivorship was 98.2% (95% CI: 95.7-99.3%) for Cohort 1 and 97.5% (95% CI: 92.6-99.2%) for Cohort 2 (p = 0.4366).

CONCLUSION

Cementless TKA exhibited similar or greater patient outcomes, satisfaction, and function up to 2 years postoperative, while both cohorts showed comparable rates of adverse events and survivorship at 5-year follow-up. This evidence underscores the clinical value and safety of cementless TKA.

Cementless fixation in total knee arthroplasty: current evidence and future perspective

INTRODUCTION

Cementless fixation plays an increasing role in total knee arthroplasty (TKA). The objective of this review article is to analyze functional outcomes and survivorship of cementless TKA.

MATERIALS AND METHODS

A comprehensive literature search for studies reviewing the outcome and survivorship of cementless TKA was conducted. This search was based on the PRISMA 2020 guidelines using PubMed, Medline, and Embase. The included studies were screened by two independent observers.

RESULTS

From 2010 to 2022, fifteen studies were included. Eleven studies compared cementless and cemented TKA. Four studies only covered cementless implants. Survivorship and functional outcomes of cementless TKA are at least comparable to those of cemented implants.

CONCLUSION

With improvement in manufacturing, and surgical tools for more precise delivery, such as robotic assisted TKA and 3D-printed implants, one can expect increase in usage of cementless TKA, due to a more biological fixation, better survivorship, and outcomes.

Comparison of Cemented and Cementless Fixation in Total Knee Arthroplasty: A Meta-Analysis and Systematic Review of RCTs

OBJECTIVE

This study aimed to compare infection, aseptic loosening, revision, operation time, function scores, and the radiographic radiolucent line (RLL) between cementless and cemented fixation in total knee arthroplasty (TKA).

METHODS

Articles reporting the outcomes of cemented and cementless TKA were searched in Medline, EMBASE, Web of Science, and the Cochrane Library. The search was conducted from articles published from January 1996 to May 2024. Odds Ratios (OR) and confidence intervals (CI) were used to measure the results. Cochrane Collaboration's Review Manager software was used to perform the meta-analysis.

RESULTS

Sixteen randomized controlled trials containing 2358 participants were included in this meta-analysis. Pooled data found that, in TKA, there were no significant differences between cemented fixation and cementless fixation for a prosthesis in infection, aseptic loosening and revision. The subgroup analysis and sensitivity analysis results of the knee society score (KSS) showed a significant difference favoring cementless fixation in a follow-up of less than 5 years (MD = -2.30, 95%CI -3.85 -0.74, p = .001) while favoring cemented fixation in a follow-up over 5 years (MD = 2.79, 95%CI 0.95 4.63, p = .003). The operation time of cementless was less than that of cemented (MD = 12.03, 95%CI 8.30 15.77, p < .00001). No significant difference was detected in knee society function score, Western Ontario and McMaster Universities osteoarthritis index, and RLL. There was no heterogeneity across studies (p > .1), and most studies have a low risk of bias.

CONCLUSIONS

Within a follow-up period of less than 5 years, cementless TKA had better KSS, while over 5 years, KSS was better in cemented TKA, and cementless TKA required less operation time.

The Utilization of Press-Fit Total Knee Arthroplasty is Not Evenly Distributed: A National Registry Review

BACKGROUND

This study evaluates trends of cemented versus press-fit total knee arthroplasty (TKA). We hypothesized that press-fit TKA is more common in younger and obese patients. There may also be racial, geographic, and institutional variation.

METHODS

The American Joint Replacement Registry was used to conduct a retrospective review of primary TKA procedures for osteoarthritis in the United States between January 2019 and March 2022. The objective was to identify differences in incidence, demographics, body mass index (BMI), Charlson Comorbidity Index (CCI), and institutional teaching status (teaching vs. non-teaching) between press-fit and cemented TKAs.

RESULTS

Two hundred ninety-seven thousand four hundred two patients (61% female, average age 68 years, 88.3% White) underwent cemented TKA versus 50,880 patients (52% female, average age 65 years, 89% White) underwent press-fit TKA. Overall, 20.8% of press-fit versus 19.9% of cemented TKA had a BMI of 35 to 39.9 and 15.2% of press-fit versus 12.5% of cemented TKA had BMI >40 ( P < 0.001). Patients undergoing press-fit TKA were less likely Black (OR = 0.727; P < 0.0001), Asian (OR = 0.651, P < 0.0001), and Native Hawaiian/other Pacific Islander (OR = 0.705, P < 0.02) with White as the reference group. Northeastern and Southern United States were more likely to use press-fit TKA than the Midwest (OR = 1.89 and OR = 1.87, P < 0.0001) and West (OR = 1.67; and OR = 1.65; P < 0.0001). Press-fit TKA incidence in 2019 was 9.9% versus 20.6% in 2022 ( P < 0.001).

CONCLUSION

Press-fit TKA is increasingly more common in Northeastern and Southern United States, and patients are older than expected. Patients with BMI >35 had a slightly higher rate of undergoing press-fit than cemented TKA. Notable racial differences also exist. Additional research addressing racial disparities and evaluating longevity of press-fit designs is needed.

Cementless and Cemented Total Knee Arthroplasties Have Similar Outcomes but Cementless Patellar Component Migration was Observed in a Paired Randomized Control Trial

BACKGROUND

Cementless total knee arthroplasty (TKA) has become increasingly popular. Some surgeons are concerned about pain, implant stability, and metal-backed patellar component survivorship. This study investigated the outcomes of cementless compared with cemented TKA in bilateral cases.

METHODS

We randomized 80 knees in 40 osteoarthritic knee patients who underwent bilateral TKA with patellar resurfacing under one anesthesia. All participants received cementless prostheses in one knee and cemented prostheses in the other. The outcomes were knee function measured by the forgotten joint scores, modified Western Ontario and McMaster Universities Osteoarthritis Index, knee ranges of motion, pain levels, operative times, radiographic outcomes, and complications. All knees were followed for a minimum of 2 years (2 to 3 years).

RESULTS

Cementless and cemented TKA had similar functional outcomes in forgotten joint score (97 ± 5 versus 98 ± 3 points, P = .52), modified Western Ontario and McMaster Universities Osteoarthritis Index score (3 ± 4 versus 3 ± 2 points, P = .96), and ranges of motion (134 ± 7° versus 134 ± 7°, P = .16). The postoperative pain was also similar (P > .05). There were 4 cementless patellar components had superior migration for an average of 3.5 mm (range, 1.77 to 4.16) without loosening. The mean time of migration was 4 (range, 2 to 6) weeks.

CONCLUSIONS

Cementless TKA had similar functional outcomes and recovery patterns compared with cemented TKA. However, there was concern of cementless component migration at patellae.

Patient Selection in Randomized Controlled Trials of Total Knee Arthroplasty: A Systematic Review Assessing Inclusion Criteria

BACKGROUND

Patients undergo total knee arthroplasty (TKA) at widely disparate stages of osteoarthritis, raising the possibility of high heterogeneity among patients enrolled in TKA research studies. Obscuration of treatment effectiveness and other problems that may stem from cohort heterogeneity can be controlled in clinical studies by rigorously defining target patients. The purpose of this review was to determine the extent to which randomized controlled trials (RCTs) on TKA use osteoarthritis severity, as defined by radiographic grade or patient-reported outcome measures (PROMs), in their inclusion criteria, and to investigate potential impact on outcome.

METHODS

A search of PubMed, Embase, Scopus, Web of Science, and Cochrane databases used a combination of terms involving TKA, PROMs, and radiographic scoring. A total of 1,227 studies were independently reviewed by 2 screeners for the above terms. RCTs with ≥100 patients (236) and with <100 patients (325) undergoing TKA were analyzed with regard to the specific inclusion criteria and recruitment process.

RESULTS

Among the identified RCTs with ≥100 patients, 18 (<8%, with a total of 2,952 randomized patients) used specific radiographic scoring or PROM thresholds in their inclusion criteria. Eleven of the 18 studies used specific radiographic scoring, such as the Kellgren-Lawrence or Ahlbäck classifications. Three studies used preoperative PROM thresholds: Knee Society Knee Score of <60, Knee Society Function Score of <60, Oxford Knee Score of <20, and Hospital for Special Surgery Score of <60. Among studies with <100 patients, 48 (<15%) used specific inclusion criteria.

CONCLUSIONS

The vast majority of RCTs (>85%) did not enroll patients based on disease severity, as measured by PROM score thresholds or radiographic classifications, in their inclusion criteria. The lack of consistent inclusion criteria likely results in heterogeneous cohorts, potentially undermining the validity of RCTs on TKA.

LEVEL OF EVIDENCE

Prognostic Level I . See Instructions for Authors for a complete description of levels of evidence.

Results of a Highly Porous Metal-Backed Cementless Patella Implant: A Minimum 5-Year Follow-Up

Initial design cementless metal-backed patellar implants failed due to multiple reasons including implant design, use of first-generation polyethylene, and surgical technique. This study evaluates clinical outcomes and survivorship of total knee arthroplasty (TKA) using a current generation highly porous metal-backed patellar component. One-hundred twenty-five consecutive primary cementless TKAs with a compression molded highly porous metal-backed patella were reviewed. One-hundred three TKAs (82.4%) with 5-year clinical and radiographic follow-up were available for review. These were matched with 103 consecutive TKAs using a cemented patella of the same implant design. The cementless cohort had a mean age of 65.5 years, body mass index (BMI) of 33.0, and follow-up of 64.4 months. Indications for cementless TKA were based on multiple factors including age, BMI, and bone quality. There were no revisions for loosening or mechanical failure of the cementless patella compared with two cemented patellae revised for aseptic loosening. Eight patients required revisions in the cementless cohort: three for prosthetic joint infection (PJI), two for instability, one periprosthetic femur fracture, one for patella instability, and one for extensor mechanism rupture. Five patients required revisions in the cemented cohort: two for aseptic patellar loosening, one for aseptic femoral loosening, one for PJI, and one for instability. All-cause survivorship at 5 years was 92.2 and 95.1% for the cementless metal-backed implant and cemented implant cohorts, respectively. Use of a compression molded highly porous metal-backed patella component demonstrated excellent clinical and radiographic results at 5-year follow-up. Longer follow-up is required to evaluate the ability of highly porous cementless patella implants to provide durable long-term fixation.

Cementless metal-backed patellar components in primary total knee arthroplasty using an implant of modern design

Aims

The use of cementless total knee arthroplasty (TKA) components has increased during the past decade. The initial design of cementless metal-backed patellar components had shown high failure rates due to many factors. The aim of this study was to evaluate the clinical results of a second-generation cementless, metal-backed patellar component of a modern design.

Methods

This was a retrospective review of 707 primary TKAs in 590 patients from a single institution, using a cementless, metal-backed patellar component with a mean follow-up of 6.9 years (2 to 12). A total of 409 TKAs were performed in 338 females and 298 TKAs in 252 males. The mean age of the patients was 63 years (34 to 87) and their mean BMI was 34.3 kg/m2 (18.8 to 64.5). The patients were chosen to undergo a cementless procedure based on age and preoperative radiological and intraoperative bone quality. Outcome was assessed using the Knee Society knee and function scores and range of motion (ROM), complications, and revisions.

Results

A total of 24 TKAs (3.4%) in 24 patients failed and required revision surgery, of which five were due to patellar complications (0.71%): one for aseptic patellar loosening (0.14%) and four for polyethylene dissociation (0.57%). A total of 19 revisions (2.7%) were undertaken in 19 patients for indications which did not relate to the patella: four for aseptic tibial loosening (0.57%), one for aseptic femoral loosening (0.14%), nine for periprosthetic infection (1.3%), one for popliteus impingement (0.14%), and four for instability (0.57%). Knee Society knee and function scores, and ROM, improved significantly when comparing pre- and postoperative values. Survival of the metal-backed patellar component for all-cause failure was 97.5% (95% confidence interval 94.9% to 100%) at 12 years.

Conclusion

The second-generation cementless TKA design of metal-backed patellar components showed a 97.5% survival at 12 years, with polyethylene dissociation from the metal-backing being the most common cause of patellar failure. In view of the increased use of TKA, especially in younger, more active, or obese patients, these findings are encouraging at mean follow-up of seven years.

A prospective randomised controlled trial of cemented and uncemented tibial baseplates: functional and radiological outcomes

INTRODUCTION

With the success of uncemented fixation in younger patients undergoing total hip arthroplasty and the growing demand for total knee arthroplasty (TKA) in a younger cohort of patients, there has been an increasing interest in cementless tibial baseplate fixation. We sought to determine whether there was a clear advantage to the use of three different forms of tibial baseplate fixation. The primary outcome of this study was survivorship and secondary outcomes were functional and radiological outcomes, up until 10 years.

MATERIALS AND METHODS

We conducted a randomised controlled trial and recruited 224 patients with 274 knees. Patients underwent TKA by a single surgeon utilising a standard surgical technique. All patients received a cruciate retaining TKA with a cementless femoral component, and were randomised to receive either a cemented tibial component, a pegged porous coated cementless tibial component with screws or a cementless tantalum monoblock tibial component with pegs. Patient reported outcome measures (PROMS), radiological data and survivorship were assessed until 10 years post-operatively.

RESULTS

Pre-operative range of motion, alignment and PROMS were similar between the three groups. The use of cemented, cementless with screws or cementless with pegs fixation options, lead to differences in functional outcomes. There was greater improvement in the Oxford score and Knee Society Score in patients who received a cemented baseplate compared to tantalum and the pegged porous groups. However, radiological and survival outcomes were similar in all three groups. Overall survivorship was 99.6%, with one knee with cementless tibial fixation and screws revised for subsidence at 3 years. There were no cases of venous thromboembolism, periprosthetic fracture or infection.

CONCLUSIONS

Irrespective of tibial fixation method, functional and radiological outcomes remain similar at follow-up at 10 years, with no clear difference in outcome between each group. Each method of fixation also had excellent survivorship over this period and should reassure surgeons that whichever method of fixation they choose, long-term outcomes are likely to be satisfactory.

Cementless Compared to Cemented Total Knee Arthroplasty is Associated With More Revisions Within 1 Year of Index Surgery

Background

Cementless total knee arthroplasties (TKAs) have gained renewed interest due to improved implant designs and lower rates of revision than its cemented counterparts. The purpose of this study was to compare revision rates between cemented vs cementless TKAs within 1 year of primary arthroplasty.

Methods

This was a retrospective review from the PearlDiver Patient Record Database. International Classification of Diseases and Current Procedural Terminology codes were used to identify patients who had undergone cemented and cementless TKAs and subsequent surgical revisions. An unadjusted univariate analysis of patient demographics, Charlson Comorbidity Index score, and surgical revisions at 90 days and 1 year after TKA was performed using chi-squared testing. Multivariate logistic regression analyses were subsequently performed for 1-year surgical complications requiring revision.

Results

Of 324,508 patients, 312,988 (96.45%) underwent cemented TKAs, and 11,520 (3.55%) underwent cementless TKAs. Patients undergoing cementless TKA tended to be younger than patients undergoing cemented TKA (63.67 ± 9.15 cementless vs 66.22 ± 8.85 cemented, P < .001). Univariate chi-squared testing showed that cementless patients were more likely to require 1-component femoral or tibial revision at 90 days and 1 year, irrigation and debridement at 90 days and 1 year, and arthroscopy with lysis of adhesions at 1 year only. Similar findings were observed for these 3 revision procedures at 1 year after correcting for age, gender, and Charlson Comorbidity Index score using multivariate logistic regression analysis as cementless TKA patients had higher odds ratios for each of the revisions.

Conclusions

Small but significant differences were found in surgical revisions among cementless TKAs when compared to cemented TKAs within 1 year of the index procedure.

Cementless Metal-Backed Patellar Components in Primary Total Knee Arthroplasty: An Average 10-Year Follow-Up

BACKGROUND

Historically, 1st generation metal-backed cementless patellar implants demonstrated high failure rates due to multiple factors. The 2nd generation cementless implants were developed with purported improvements in component design and polyethylene wear characteristics. This study evaluated clinical results of a current generation cementless metal-backed patellar implant with a minimum 5-year follow-up.

METHODS

One hundred and thirty-six primary total knee arthroplasties (TKAs) with metal-backed cementless patellae were compared to 183 cemented patellae with the same implant design. The cementless group mean age was 61 years (range, 40 to 81), mean body mass index (BMI) of 34.9 (range, 22.6 to 64.5), and mean follow-up of 10 years (range, 5 to 13). The cemented group mean age was 65 years (range, 32 to 89), mean BMI of 32.5 (range, 18.2 to 56.6), and mean follow-up of 10 years (range, 5 to 12). Significant demographic differences of age (P < .001), BMI (P < .01), and sex (P < .001) were found, with cementless patients being younger, heavier, and with more men.

RESULTS

There were no statistical differences in non-revision procedures (P = .214), TKA revisions (P = .639), patellar revisions (P = .151), and patellar aseptic loosening (P = .737). The 10-year survivorship of the cementless metal-backed patella was 95.9% with all-cause failure as the endpoint. The 10-year survivorship of the cemented patellar component was 98.9%.

CONCLUSION

This study demonstrated noninferiority of a 2nd generation HA-coated cementless metal-backed patellar implant in primary TKA compared to cemented patellae with 10-year survivorship of 95.9%. Advances in implant design and polyethylene wear properties have led to improved clinical results with metal-backed patellar components in primary TKA.

Is Cementless Total Knee Arthroplasty Safe in Women Over 75 Y of Age?

BACKGROUND

Cementless total knee arthroplasty (TKA) is the subject of renewed interest. Previous concerns about survivorship have been addressed and there is an appeal in terms of biological fixation and surgical efficiency. However, even surgeon advocates have concerns about the risk of marked subsidence when using this technology in older patients at risk for osteoporosis.

METHODS

This was a retrospective analysis of 1,000 consecutive fully cementless mobile bearing TKAs performed at a single institution on women over 75 years of age who had postoperative and 1-year x-rays. The primary outcome was the incidence of subsidence.

RESULTS

There were three asymptomatic cases with definite subsidence and change in alignment. In a fourth symptomatic case, the femoral component subsided into varus and the tibia into valgus, thus maintaining alignment which facilitated nonoperative treatment in a 92-year-old. Overall, at 1 year, there were two- liner revisions for infection without recurrence. Five patients had further surgery, of which three were washouts and two were for periprosthetic fractures sustained postoperatively within 1 year. Seven patients had further anesthesia, of which five were manipulations and two were nonrecurrent closed reductions for spinouts.

CONCLUSION

Cementless TKA did not have a high risk of subsidence in this at-risk population. In the hands of experienced surgeons, these procedures can be used safely irrespective of bone quality.

Cementless Mobile-Bearing Total Knee Arthroplasty: 10 Years Follow-Up

Background Although most TKR surgeries are cemented, the interest in cementless TKR has increased dramatically during the last few years because of the new generation of cementless prostheses and the increased number of young patients who need TKR. Methods Ten years of retrospective reviews of 80 patients who had cementless, complete rotating platform TKR (DePuy Synthes, Warsaw, Indiana) were performed. Patients were divided into two groups according to their age (above and below 70 years old). Functional outcomes at the final follow-up were evaluated clinically by filling out a satisfaction form, and the Oxford Knee Score as well as all medical and surgical complications were recorded for each patient. Results The 10-year cumulative implant survival rate was 100%, i.e. no patients had revision surgeries with no significant statistical difference between the two age groups. The 10-year evaluation rate was 90%. Conclusion The use of cementless TKA exhibited good survivability, long-term clinical and functional results, and no implant revision in various age groups, as well as a high satisfaction rate. There was no statistically significant difference between the results of different age groups.

Cementless and Cemented Dual-pivot Total Knee Arthroplasty: A Matched Comparison with a Minimum Two-year Follow-up

INTRODUCTION

With the use of newer biomaterials, many authors have reported similar results between cementless and cemented total knee arthroplasty (TKA). The purpose of this study was to compare the early clinical and radiographic outcomes of cementless and cemented TKA using the same dual-pivot articulation.

METHODS

A consecutive series of 806 TKAs were implanted by a single surgeon using the same dual-pivot articulation. There were 634 TKAs (79%) cemented and 172 (21%) uncemented. One patient in the cementless group was lost before two years. The remaining 171 cementless TKAs were matched 1:1 with cemented TKAs with respect to age, sex, and body mass index (BMI). All patients were followed for a minimum of two years (range, 24 to 66 months) using the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR), and Knee Society clinical and radiographic evaluation. The average follow-up was 3.8 years (range, 24-66 months) in the cemented group and 3.4 years (range,24-56 months) in the cementless group.

RESULTS

At final follow-up, the average KOOS-JR score was higher in the cementless group (86 points (range, 64-100) vs. 80 points (range, 57-100). Post-op Knee Society scores (including pain and function) were similar. There was one deep infection (cemented TKA). The manipulation rate was 1.2% in the cementless group and 2.4% in the cemented TKA group. Excluding infection, two knees (1.2%) were revised in each group. No cases of femoral or tibial component loosening were identified.

CONCLUSION

Patients implanted with either a cemented or cementless TKA using the same conforming dual-pivot articulation design had similar early outcomes and functional improvements. The type of fixation did not appear to influence the early clinical results.

Uncemented Tibial Fixation Has Comparable Prognostic Outcomes and Safety Versus Cemented Fixation in Cruciate-Retaining Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Cemented and uncemented fixation are the primary methods of tibial prosthesis fixation in total knee arthroplasty. However, the optimal fixation method remains controversial. This article explored whether uncemented tibial fixation has better clinical and radiological outcomes, fewer complications, and revision rates compared to cemented tibial fixation.

METHODS

We searched the PubMed, Embase, Cochrane Library, and Web of Science databases up to September 2022 to identify randomized controlled trials (RCTs) that compared uncemented total knee arthroplasty (TKA) and cemented TKA. The outcome assessment consisted of clinical and radiological outcomes, complications (aseptic loosening, infection, and thrombosis), and revision rate. Subgroup analysis was used to explore the effects of different fixation methods on knee scores in younger patients.

RESULTS

Nine RCTs were finally analyzed with 686 uncemented knees and 678 cemented knees. The mean follow-up time was 12.6 years. The pooled data revealed significant advantages of uncemented fixations over cemented fixations in terms of the Knee Society Knee Score (KSKS) (p = 0.01) and the Knee Society Score-Pain (KSS-Pain) (p = 0.02). Cemented fixations showed significant advantages in maximum total point motion (MTPM) (p < 0.0001). There was no significant difference between uncemented fixation and cemented fixation regarding functional outcomes, range of motion, complications, and revision rates. When comparing among young people (<65 years), the differences in KSKS became statistically insignificant. No significant difference was shown in aseptic loosening and the revision rate among young patients.

CONCLUSIONS

The current evidence shows better knee score, less pain, comparable complications and revision rates for uncemented tibial prosthesis fixation, compared to cemented, in cruciate-retaining total knee arthroplasty.

The Evolution, Current Indications and Outcomes of Cementless Total Knee Arthroplasty

Total knee arthroplasty (TKA) has been performed by orthopedic surgeons for decades, but the cementless TKA has only recently gained much interest in the world of arthroplasty. Initially, early designs had multiple complications, particularly with aseptic loosening due to osteolysis and micromotion. However, modifications have shown good outcomes and excellent survivorship. Over the last several decades, changes in implant designs as well as implant materials/coatings have helped with bone in growth and stability. Furthermore, surgeons have been performing TKA in younger and more obese patients as these populations have been increasing. Good results from the cementless TKA compared to cemented TKA may be a better option in these more challenging populations, as several studies have shown greater survivorship in patients that are younger and have a greater BMI. Additionally, a cementless TKA may be more cost effective, which remains a concern in today's healthcare environment. Overall, cemented and cementless TKA have great results in modern times and there is still a debate as to which implant is superior.

Press-Fit Dual-Pivot Total Knee Arthroplasty: Early Results With a Minimum 2-Year Follow-Up

BACKGROUND

Ultracongruent (UC) tibial bearings are being used with increasing frequency in the United States. Evidence suggests that the use of certain UC bearings may lead to improved patient satisfaction when compared with using conventional inserts. However, little is known as to what effect the use of UC tibial inserts has on bone ingrowth in uncemented total knee arthroplasty (TKA). The purpose of this study was to determine the early clinical and radiographic results of TKA using a press-fit dual-pivot design.

METHODS

Between 2017 and 2019, a consecutive series of 232 TKAs were implanted using a press-fit tibial and femoral component and a UC dual-pivot tibial insert. Sixty-two percent of patients were male. The average age was 56 years. Patients were followed for a minimum of 2 years (range, 24-42 months) using KOOS-JR and Knee Society clinical and radiographic evaluation.

RESULTS

No patient had more than mild knee stiffness at the final follow-up. Two patients reported moderate knee pain with stair climbing. All other patients reported either mild or no pain with activity. Knee Society pain scores averaged 42 points. Flexion averaged 118 degrees. Three knees (1.3%) were revised (one each for flexion instability, tibial plateau fracture, and suspected femoral component loosening). No other cases of femoral or tibial loosening were identified.

CONCLUSION

Although the success of uncemented TKA is determined by a variety of factors, the use of this dual-pivot knee design did not appear to influence tibial or femoral component fixation at early follow-up, yielding acceptable clinical and radiographic outcomes.

Long-term effects of cemented and cementless fixations of total knee arthroplasty: a meta-analysis and systematic review of randomized controlled trials

BACKGROUND

To determine the long-term effects (a minimum follow-up time 8.8 years) of cemented and cementless fixations used for total knee arthroplasty (TKA).

METHODS

PubMed, EMBASE, Ovid, Cochrane Library, CINAHL, China National Knowledge Infrastructure and China Wangfang database were interrogated for appropriate randomized controlled trials (RCTs) through July 2020. Data were extracted and assessed for accuracy by 2 of the authors acting independently. Any controversial discrepancies were resolved after discussion with a third author.

RESULT

Eight RCTs were included with low to moderate bias risks. The cemented fixation of TKA was comparable to cementless fixation in terms of implant survival (relative risk, 1.016; 95% CI 0.978 to 1.056; P = 0.417), Knee Society (KS) knee score (standardized mean difference (SMD), - 0.107; 95% CI - 0.259 to 0.045; P = 0.168), KS function score (SMD - 0.065; 95% CI - 0.238 to 0.109; P = 0.463), KS pain score (SMD - 0.300; 95% CI - 0.641 to 0.042; P = 0.085), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score (SMD - 0.117; 95% CI - 0.307 to 0.073; P = 0.227), HSS score (SMD - 0.027; 95% CI - 0.270 to 0.217; P = 0.829), range of motion (SMD 0.061; 95% CI - 0.205 to 0.327; P = 0.652) at ≥ 8.8 years of follow-up. In terms of radiographic outcomes at ≥ 8.8 years of follow-up, the incidence of a radiolucent line in the cementless group was lower than for the cemented group (SMD 3.828; 95% CI 2.228 to 6.576; P < 0.001). However, the maximum total point motion (MTPM) of the cementless group was greater than for the cemented group (SMD - 0.739; 95% CI - 1.474 to - 0.005; P = 0.048).

CONCLUSIONS

Long-term follow-up verified that cementless and cemented fixation have similar prosthesis survival rates, clinical scores and mobility. However, radiography suggested that each technique had an advantage with regard to the radiolucent line and MTPM.

Primary Stability in Cementless Rotating Platform Total Knee Arthroplasty

Highly porous ingrowth surfaces have been introduced into tibial tray fixation to improve long-term survivorship in cementless total knee arthroplasty. This study was designed to evaluate the effect of porous ingrowth surface on primary stability in the implanted cementless tibial component. Three tibial tray designs possessing sintered bead or roughened porous coating ingrowth surfaces were implanted into a foam tibia model with primary stability assessed via digital image correlation during stair descent and condylar liftoff loading. Follow-up testing was conducted by implanting matched-pair cadaveric tibias with otherwise identical trays with two iterations of ingrowth surface design. Trays were loaded and micromotion evaluated in a condylar liftoff model. The sintered bead tibial tray exhibited slightly lower micromotion than the roughened porous coating in stair descent loading. However, no significant difference in primary stability was observed in condylar liftoff loading in either foam or cadaveric specimens. Cementless tibial trays featuring two different iterations of porous ingrowth surfaces demonstrated both good stability in cadaveric specimens with less than 80 microns of micromotion and 1 mm of subsidence under cyclic loading. While improved ingrowth surfaces may lead to improved biological fixation and long-term osteointegration, this study was unable to identify a difference in primary stability associated with subsequent ingrown surface design iteration.

Cemented vs. cementless fixation in primary total knee arthroplasty: a systematic review and meta-analysis

Over 100,000 total knee replacements (TKRs) are carried out in the UK annually, with cemented fixation accounting for approximately 95% of all primary TKRs. In Australia, 68.1% of all primary TKRs use cemented fixation, and only 10.9% use cementless fixation. However, there has been a renewed interest in cementless fixation as a result of improvements in implant design and manufacturing technology.

This meta-analysis aimed to compare the outcomes of cemented and cementless fixation in primary TKR. Outcome measures included the revision rate and patient-reported functional scores.

MEDLINE and EMBASE were searched from the earliest available date to November 2018 for randomized controlled trials of primary TKAs comparing cemented versus cementless fixation outcomes.

Six studies met our inclusion criteria and were analysed. A total of 755 knees were included; 356 knees underwent cemented fixation, 399 underwent cementless fixation. They were followed up for an average of 8.4 years (range: 2.0 to 16.6).

This study found no significant difference in revision rates and knee function in cemented versus cementless TKR at up to 16.6-year follow-up.

Cite this article: EFORT Open Rev 2020;5:793-798. DOI: 10.1302/2058-5241.5.200030

Hybrid fixation versus full-cemented or full-cementless fixation in total knee arthroplasty: Systematic review and meta-analysis of comparative studies

OBJECTIVE

Hybrid fixation is one alternative to full-cemented fixation in total knee arthroplasty (TKA) with theoretical advantages. Hybrid fixation may offer the advantages of cementless femoral fixation, while also avoiding the problem of tibial loosening in full-cementless TKA. The purpose of the study is to determine whether hybrid TKA may perform comparably to or better than full-cemented and full-cementless TKA.

METHODS

We searched the MEDLINE, EMBASE and Cochrane Library databases through September 2018 for randomized controlled trials and observational studies comparing outcomes of hybrid versus full-cemented or full-cementless fixation techniques. Outcomes of interest included aseptic loosening, overall reoperation rate, infection, radiolucent lines and operating time. Data were pooled with the Mantel-Haenszel random effects model.

RESULTS

We included 14 studies with follow-up ranging from 2.7 to 9.6 years in our quantitative analysis, of which 7 studies compared hybrid fixation with full-cemented TKA and another 7 compared hybrid fixation with full-cementless TKA. Combined data revealed that the hybrid fixation group had a similar rate of aseptic loosening compared with cemented (P = 0.19) and cementless (P = 0.49) groups. There was no difference with respect to other outcomes, including overall reoperation rate, infection, radiolucent lines and operating time between groups.

CONCLUSION

Hybrid, cementless and cemented TKAs have comparable mid-term results as it pertains to aseptic loosening, overall reoperation, infection, radiolucent lines and operating time. Further comparative studies are needed to investigate these potential effects over the long-term.

Clinical Outcomes and Survivorship of Contemporary Cementless Primary Total Knee Arthroplasties

BACKGROUND

Total knee arthroplasties (TKAs) with cementless fixation have been studied in multiple series with varying success. The aim of this study was to prepare a systematic review of the literature to evaluate clinical outcomes and revtpdelision rates of patients undergoing contemporary cementless TKA.

METHODS

A search of PubMed and MEDLINE was conducted for English-language articles published between 2005 and 2018 to identify studies examining survivorship and clinical outcomes of cementless TKAs. Studies that reported clinical and/or radiographic outcomes were included. Data collected included the number of TKAs, implant utilized, primary diagnosis, mean age and follow-up, implant survivorship, complications, revisions, and clinical outcome scores. All hybrid constructs and revision TKAs were excluded. Poisson regression analysis was used to determine the revision incidence rates per 1,000 person-years.

RESULTS

Forty-three studies with 10,447 TKAs met inclusion criteria, of which 8,187 were primary cementless TKAs. The mean follow-up was 7 years. The revision incidence per 1,000 person-years was 4.8 for all cementless designs. The complication rate for all cementless TKAs was 6%, with deep venous thrombosis being the most common complication. The mean postoperative Knee Society Score and Functional Score were 92 and 83, respectively.

CONCLUSIONS

While newer-generation cementless designs have shown improved survivorship and clinical outcomes compared with earlier-generation cementless designs, the literature for cementless designs remains limited when compared with cemented designs. Further studies are needed to determine if cementless TKA can achieve the same benefits that have been realized with cementless total hip arthroplasty.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Survival rate of cemented versus cementless tibial component in primary total knee arthroplasty over 5 years of follow-up: comparative study of 109 prostheses

INTRODUCTION

Knee osteoarthritis is the main indication for primary total knee arthroplasty (TKA). It is now accepted that cementless implantation of the femoral component provides equivalent results to cemented one, however, the optimal fixation method of the tibial component remains controversial. The purpose of this study was to compare the survivorship of cemented versus cementless tibial baseplate in primary total knee arthroplasty.

MATERIALS AND METHODS

We carried out a retrospective, monocentric study, including 109 TKA (Zimmer^® Natural Knee II ultra-congruent mobile-bearing) implanted between 2004 and 2010 for primary osteoarthritis, comparing 2 groups depending on tibial component fixation method, one cemented (n = 68) and one cementless (n = 41). Clinical (Knee Society Rating System (KSS), Hospital for Special Surgery (HSS) scores, range of motion) and radiodiological outcomes were assessed at last follow-up with a minimal follow-up of 5 years.

RESULTS

Mean follow-up were 8.14 [5.31-12.7] and 8.06 [5.22-12.02] years, respectively, in cemented and cementless groups. The tibial component survival rate was 100% [95CI: 91.4-100] in the cementless group and 97.1% [95CI: 89.78-99.42] in the cemented group (2 aseptic loosenings) (p = 0.27). Radiolucent lines were present in 31.7% (n = 13) of the cementless and 44.1% (n = 30) of the cemented baseplates (p = 0.2). The postoperative KSS knee score was higher in the cementless group (99 ± 3 vs. 97 ± 7.5; p = 0.02), but there was no significant difference in KSS function, global KSS and HSS scores. Mean range of flexion was 120 ± 10° in the cementless group and 122.5 ± 15° in the cemented group (p = 0.37). No significant differences were found on the radiographic data or on complications.

CONCLUSION

In this study, the survival rate of the tibial component is not influenced by its fixation method at a mean follow-up of 8 years in osteoarthritis, which confirms the reliability of cementless fixation in primary TKA.

Comparison of infection in cemented, cementless and hybrid primary total knee arthroplasty: a network meta-analysis and systematic review of randomized clinical trials

BACKGROUND

Prosthetic joint infection (PJI) is a serious complication of joint replacement surgeries. Surgeons often take extra measures to reduce the risk of PJI. Whilst many studies have compared between cemented, cementless and hybrid fixation (femoral cementless, tibial cemented), most focus on survivorship, clinical and function outcome scores as primary endpoints. This meta-analysis aims to study the association between fixation methods and risk of PJI in primary total knee arthroplasty (TKA).

METHODS

A systematic review and network meta-analysis of randomized controlled trials (RCT) were performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Data from studies assessing prevalence of PJI in each fixation type were extracted and analysed.

RESULTS

Twelve RCT comprising a total of 1573 knees were included. Six RCT compared between cemented (n = 486 knees) and cementless (n = 440 knees) fixation, while six RCT compared between hybrid (n = 324 knees) and cementless (n = 323 knees) fixation. Network meta-analysis did not reveal any fixation type that significantly increased the infection rate in TKA. Rate of all infection was lowest in cemented TKA as compared to cementless (odds ratio (OR) 0.90, 95% confidence interval (CI) 0.35-2.28) and hybrid (OR 0.63, 95%CI 0.13-2.99) TKA. Rate of PJI requiring revision surgery was lowest in cementless TKA as compared to cemented (OR 0.89, 95%CI 0.30-2.41) and hybrid (OR 0.57, 95%CI 0.09-2.71) TKA. Rate of PJI not requiring revision surgery was lowest in cemented TKA as compared to hybrid (OR 0.56, 95%CI 0.06-6.10) and cementless (OR 0.55, 95% 0.14-5.63).

CONCLUSION

Unlike total hip arthroplasties, fixation method is not a predisposing risk factor for infections in TKA. However, this meta-analysis may not have sufficient statistical power to show a significant difference between fixation types. It is recommended that prophylactic precautions against other known risk factors for infection should still be clinically practiced.

LEVEL OF EVIDENCE

Level I, meta-analysis of randomized controlled trials.

Functional outcomes comparative analysis of cemented and uncemented total knee arthroplasty

Introduction

Cementless knee arthroplasty becomes more and more popular worldwide. At the beginning of endoprosthetics era, cementless implants showed unsatisfactory results. However, surgical technologies develop rapidly and nowadays the cementless fixation shows better outcomes.

Objectives

To analyze the experience of total knee arthroplasty using cementless fixation for the treatment of advanced arthritis of the knee.

Methods

We operated on 130 patients. The mean follow-up duration was 36 months. In 70 patients we used cementless fixation and in 60 patients we used implants with cemented fixation. To evaluate the results, we used KOOS scale and WOMAC scale. We also evaluated the mean duration of surgical intervention and blood loss.

Results

In the cementless group WOMAC and KOOS scales scores before the operation were 198,2 (±35.7) and 23,1 (±3.4), respectively, and in the cemented group it was 199.3(±36.8) and 24.9 (±2.1), respectively(p > 0,05). One year after the operation, KOOS and WOMAC scores were 54.5(±12.6) and 83.6(±8,.2) in the cementless group and 78.9(±4.6) and 66.9(±5.7) in the cemented group(p < 0,05)., respectively. Intraoperative blood loss was 255(±89,3) in the cemented group and 315(±52,1) in cementless group(p < 0,05). Postoperative blood loss was 515(±119, 5) and 440(±129,3)) (p < 0,05), respectively. Mean duration of intervention was 78 min (±6,8) in cemented group and 64 min (±8,7) in cementless group(p < 0,05).

Conclusions

1We have better functional results using implants with cementless fixation.2There was a greater intraoperative and postoperative blood loss in cementless group.3Cementless knee arthroplasty associated with shorter duration of intervention than cemented.

Better outcomes are associated with cementless fixation in primary total knee arthroplasty in young patients: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The use of cemented and cementless fixations in primary total knee arthroplasty (TKA) in young patients is controversial. Previous reviews predominantly relied on data from retrospective studies. This systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated the optimal fixation mode in TKA for young patients.

METHODS

The PubMed, Embase, Medline, Web of Science, and full Cochrane Library electronic databases were searched from inception to July 2018. The outcome measurements consisted of functional outcomes (Knee Society Score [KSS], range of motion [ROM]), radiolucent lines, aseptic loosening, total complications, and reoperation rate. Study data were pooled using a random-effects model.

RESULTS

Six RCTs were included in the systematic review and meta-analysis. The mean follow-up period was 12 years (range, 2-16.6 years). Cementless TKA was associated with higher KSS-function (P < .0001), higher KSS-pain (P = .005), better ROM recovery (P = .01), and fewer radiolucent lines (<1 mm) (P = .04) compared with cemented TKA. No significant intergroup differences were observed for KSS-knee, total complications, aseptic loosening, or reoperation rate. These results based on a random-effects model were unchanged by sensitivity analysis assumptions.

CONCLUSION

Cementless TKA was substantially superior to cemented TKA in young patients. Although the complication and survival rates were similar between groups, better clinical outcomes were obtained with cementless fixation. Further well-designed studies with long follow-up durations are necessary to confirm our findings.

Mobile-bearing total knee arthroplasty implants combined with surface cementation produced satisfactory clinical and radiographic outcomes at the 5-year follow-up

PURPOSE

Very little is known about the use of combined surface cementation (only tibial tray) and mobile-bearing tibial components in total knee arthroplasty (TKA). This study was investigated whether the index combinations show satisfactory clinical outcomes after mobile-bearing TKA using posterior cruciate ligament (PCL)-retaining meniscal-bearing (MB) and PCL-substituting rotating-platform (RP) TKA designed using different anteroposterior constraints.

METHODS

This study is a retrospective evaluation of a prospective database. Five-year postoperative clinical outcomes were assessed in 127 patients (127 knees) and 122 patients (122 knees) who underwent TKA with an MB and RP design, respectively. The Hospital for Special Surgery (HSS) score, range of motion, loosening/radiolucency, and subsidence around both components were evaluated in the two designs.

RESULTS

The postoperative median HSS score was excellent in both the MB and RP groups (93 and 92, respectively). Postoperative flexion and extension did not differ between the two designs. Neither design showed > 2-mm radiolucencies raising concern for femoral or tibial implant stability. Five (2%) of 249 patients (5 knees) (MB, n = 4; RP, n = 1) showed detectable subsidence of the tibial component. However, no revision TKA had been performed by the 5-year follow-up because no patients had complaints severe enough to necessitate revision surgery.

CONCLUSIONS

Clinically good outcomes comparable with previous studies were obtained 5 years after mobile-bearing TKA with surface cementation using both MB and RP implant designs. Thus, equivalent mid-term clinical outcomes of the index combination can be obtained with other implant designs and cementation techniques.

LEVEL OF EVIDENCE

Level II.

Total Knee Arthroplasty in Severe Valgus Deformity Using a Modified Technique-A 10-Year Follow-Up Study

BACKGROUND

Valgus knee deformity accounts for only 10% of total knee arthroplasties (TKAs), but is frequently considered the most challenging to manage. This study provides a 10-year follow-up on a previously reported series of severe valgus knees performed using an unconstrained mobile-bearing TKA with a modified technique to validate this technique.

METHODS

A consecutive series of 275 predominantly cementless TKAs in 262 patients were performed for severe valgus (≥10°) deformity and prospectively followed to 10 years. Patient-reported outcome measures included the Oxford Knee Score, American Knee Society Score, Bartlett Patellar Score, and the Short Form 12 questionnaire.

RESULTS

Average valgus deformity was reduced from 15.6° to 3.8° (P < .001). At a mean follow-up of 10.4 years (range, 9.5-14.1), 90 (34.4%) patients had died. Of the reviewed survivors, the mean Oxford Knee Score was 27.8 ± 9.8, with an American Knee Society clinical score of 85.6 ± 17.0 and a functional score of 65.1 ± 20.4, with 78% of patients reporting good to excellent results. To date, there has been 1 (0.36%) revision and 13 (4.73%) reoperations. Kaplan-Meier implant survival was 99.6% at 10 years.

CONCLUSION

Despite its challenging nature, the valgus knee is associated with excellent survivorship and satisfactory long-term results using this modified technique.

LEVEL OF EVIDENCE

Level IV.

A 9-Year Outcome Study Comparing Cancellous Titanium-Coated Cementless to Cemented Tibial Components of a Single Knee Arthroplasty Design

BACKGROUND

The cemented Advance Medial-Pivot total knee arthroplasty (TKA) was designed to reflect contemporary knee kinematics data and has shown satisfactory long-term outcomes.

METHODS

We retrospectively evaluated prospectively collected data from 2 groups of patients. Group A consisted of 54 patients (54 TKAs), 18 men and 36 women, and mean age at surgery was 63.2 ± 5.2 years; group B consisted of 54 patients (54 TKAs), 17 men and 37 women, and mean age at surgery was 63.8 ± 5.1 years. Patients of both groups were matched for age, gender, side, body mass index, and length of follow-up. The cementless components of this design were implanted in group A and the cemented in group B. Implant failure, complication rates, clinical (both subjective and objective) and radiological outcomes were assessed in all patients of both groups.

RESULTS

All patients of both groups were available for final follow-up evaluation at a mean of 8.6 ± 0.4 years. Survival analysis at 9 years showed a cumulative success rate of 100% in both groups with all end points. In neither group were implant-related, surgeon-related, or patient-related failures observed. When both groups were compared, in all time intervals, no differences were recorded on Knee Society system, Western Ontario and McMaster University Osteoarthritis Index, Short Form-12, and Oxford Knee Scores. On radiological examination, for both groups, all parameters evaluated were satisfactory.

CONCLUSION

This study presents satisfactory midterm clinical and radiological outcomes with the use of both versions of this design. Moreover, no implant-related failures were observed with the use of cancellous titanium-coated tibial implants.

Cementless Total Knee Arthroplasty: A Comprehensive Review of the Literature

This review evaluated (1) original and newer cementless implants; (2) outcomes of newer designs; (3) risks and benefits; and (4) newer cementless vs cemented total knee arthroplasties. A search for all reports on cementless total knee arthroplasties published from January 2010 to April 2017 was performed, and 31 studies were included for final analysis. Newer cementless total knee arthroplasty designs have shown excellent survivorship, functional outcomes, and satisfaction rates in both young and elderly populations. Compared with cement fixation, there may be potential benefits with the newer cementless implants. However, these findings need to be further substantiated with additional studies reporting longer-term results. [Orthopedics. 2018; 41(5):263-273.].

No difference in implant survivorship and clinical outcomes between full-cementless and full-cemented fixation in primary total knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

The debate over the use of cemented or cementless fixation in total knee arthroplasty (TKA) has never stopped since cementless fixation was introduced. We undertook a systematic review and meta-analysis to evaluate the optimal mode of fixation (full-cementless vs. full-cemented) in TKA.

METHODS

PubMed, Embase, and the Cochrane Library databases up to July 2017 were searched to identify randomised controlled trials (RCTs) and quasi-RCTs comparing full-cementless TKA and full-cemented TKA. The primary outcome was implant survivorship. Secondary outcomes included radiological outcomes (maximum total point-motion [MTPM], radiolucent line, rotation degree) and clinical outcomes (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] score, Knee Society Score [KSS] score, postoperative range of movement, blood loss and complications).

RESULTS

Seven studies were included in the systematic review and meta-analysis. The mean follow-up was 7.1 years (range from 2 to 16.6 years). There was no difference in implant survivorship (RR, 0.98; 95% CI, 0.95-1.01; p = 0.25; I² = 0%), MTPM (weighted mean difference [WMD], 0.13 mm; 95% CI, -0.69-0.95; p = 0.75; I² = 89.3%) and radiolucent line (RR, 1.36; 95% CI, 0.57-3.23; p = 0.48; I² = 54%) between the cementless and cemented methods. There was a mean 0.22° more rotation in the full-cementless fixation group (95% CI, 0.13-0.32; p < 0.01; I² = 28.5%). There were no significant differences relating to clinical outcomes (WOMAC score, KSS score, postoperative range of movement, blood loss and complications) between the two fixation groups.

CONCLUSIONS

Although more overall component rotation is found in full-cementless fixation, the implant survivorship and clinical efficacy are likely similar between full-cementless and full-cemented fixation. However, future RCTs with similar cementless prosthetic coating and longer-term follow-up are still needed to confirm our findings.

Uncemented vs Cemented Cruciate Retaining Total Knee Arthroplasty in Patients With Body Mass Index Greater Than 30

BACKGROUND

Aseptic loosening of cemented and uncemented tibial components continues to be a source of implant failure after total knee arthroplasty (TKA) in the obese population. There is limited literature reviewing uncemented cruciate retaining (CR) components in the obese population.

METHODS

A clinical and radiographic review was performed on 325 patients who underwent a cemented or uncemented TKA with a CR knee prosthesis and body mass index ≥30 kg/m² between January 2010 and June 2013. Charts were reviewed for the incidence of revision due to aseptic loosening of the tibial baseplate, revision for any reason, incidence of radiolucent lines around the tibial baseplate, range of motion, and patient reported outcomes.

RESULTS

There was no statistically significant difference between groups in survivorship for aseptic loosening of the tibial component (99.4% uncemented, 99.3% cemented, P = .94) and overall survivorship (98.1% uncemented, 98.3% cemented, P = .90). The Lower Extremity Activity Scale and Forgotten Joint Score-12 clinical outcome measures were similar between groups (10.2 ± 3.7 vs 9.7 ± 3.4 and 66.1 ± 28.2 vs 64.9 ± 24.3, P = .33, P = .78, respectively). Postoperative knee flexion was similar between groups (114.6 ± 9.3 vs 114.1 ± 9.3, P = .67).

CONCLUSION

Our study demonstrated similar survivorship of this CR design for aseptic loosening of the tibial baseplate and overall revision rates in obese patients undergoing either an uncemented or cemented TKA. The uncemented and cemented groups had comparable clinical and radiographic short to mid-term outcomes when implanted in good alignment when treating end-stage knee osteoarthritis.

Nano-carrier based drug delivery systems for sustained antimicrobial agent release from orthopaedic cementous material

Total joint replacement (TJR), such as hip and knee replacement, is a popular procedure worldwide. Prosthetic joint infections (PJI) after this procedure have been widely reported, where treatment of such infections is complex with high cost and prolonged hospital stay. In cemented arthroplasties, the use of antibiotic loaded bone cement (ALBC) is a standard practice for the prophylaxis and treatment of PJI. Recently, the development of bacterial resistance by pathogenic microorganisms against most commonly used antibiotics increased the interest in alternative approaches for antimicrobial delivery systems such as nanotechnology. This review summarizes the efforts made to improve the antimicrobial properties of PMMA bone cements using nanotechnology based antibiotic and non-antibiotic delivery systems to overcome drawbacks of ALBC in the prophylaxis and treatment of PJIs after hip and knee replacement.

Outcomes of cementless unicompartmental and total knee arthroplasty: A systematic review

BACKGROUND

Aseptic loosening is a common failure mode in cemented unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). This led to the development of cementless designs but the historical outcomes were poor. Recent developments in cementless designs have improved outcomes, but the current status is unknown. Therefore, a systematic review was performed to assess recent outcomes of cementless knee arthroplasty.

METHODS

A search was performed using PubMed, Embase and Cochrane systems and national registries for studies reporting outcomes since 2005. Fifty-two cohort studies and four registries reported survivorship, failure modes or functional outcomes of cementless UKA and TKA.

RESULTS

Nine level I studies, six level II studies, three level III studies, 34 level IV studies and four registries were included. Three hundred eighteen failures in 10,309 cementless TKA procedures and 62 failures in 2218 cementless UKA procedures resulted in extrapolated five-year, 10-year and 15-year survivorship of cementless TKAs of 97.7%, 95.4% and 93.0%, respectively, and cementless UKA of 96.4%, 92.9% and 89.3%, respectively. Aseptic loosening was more common in cementless TKA (25%) when compared to UKA (13%). Functional outcomes of cementless TKA and UKA were excellent with 84.3% and 84.5% of the maximum possible scores, respectively.

CONCLUSIONS

This systematic review showed that good to excellent extrapolated survivorship and functional outcomes are seen following modern cementless UKA and TKA, with a low incidence of aseptic loosening following cementless UKA.

LEVEL OF EVIDENCE

Level IV.

Cementless total knee arthroplasty

As the number of younger and more active patients treated with total knee arthroplasty (TKA) continues to increase, consideration of better fixation as a means of improving implant longevity is required. Cemented TKA remains the reference standard with the largest body of evidence and the longest follow-up to support its use. However, cementless TKA, may offer the opportunity of a more bone-sparing procedure with long lasting biological fixation to the bone. We undertook a review of the literature examining advances of cementless TKA and the reported results.

Cite this article: Bone Joint J 2016;98-B:867–73.

Short Term Outcomes of a Hydroxyapatite Coated Metal Backed Patella

We retrospectively evaluated the records and radiographs of 101 knees with a hydroxyapatite coated metal backed patella (HAP) and 50 knees with a cemented polyethylene patella (CP) with minimum two year clinical follow up. There were no patellar revisions during the study period. Patients in both the HAP and CP groups had similar clinical outcomes at final follow-up. Forty-five percent of patients in the HAP group had 1-2mm areas of decreased trabecular bone density around the pegs, which were not observed in the CP group, and may represent stress shielding. This uncemented HAP component has satisfactory early clinical outcomes, but long-term follow up is necessary to determine the durability of this implant.

No clinical benefit of titanium nitride coating in cementless mobile-bearing total knee arthroplasty

PURPOSE

Titanium nitride (TiN) coating of cobalt-chromium-molybdenum (CoCrMo) implants has shown to improve the biomechanical properties of the implant surface and to reduce adhesive wear in vitro. It is yet unknown whether TiN coating of total knee prosthesis (TKP) affects the postoperative clinical outcome of total knee arthroplasty (TKA).

METHODS

In a double-blind randomized controlled clinical trial, 101 patients received an uncemented mobile-bearing CoCrMo TKP, either TiN coated or uncoated. Primary outcome measure visual analogue scale (VAS) score for pain, and secondary outcome measures Knee Society Score (KSS), revision rate and adverse events, range of motion of the knee as well as knee circumference and knee skin temperature were assessed 6 weeks, 6 months, 1 year and 5 years postoperative. Repeated measures analysis was used to evaluate the postoperative outcome measures over time.

RESULTS

There was no difference between the two groups in VAS score, KSS, revision rate, range of motion of the knee, knee circumference and knee skin temperature. There were no adverse events that could be related to the TiN coating.

CONCLUSIONS

TiN-coated TKP does not influence the postoperative outcome of uncemented mobile-bearing TKA regarding postoperative pain, revision rate, range of motion, swelling and temperature of the knee. Therefore, TiN coating of CoCrMo TKP has no clinical benefit on the outcome of cementless mobile-bearing TKA.

LEVEL OF EVIDENCE

Therapeutic study, Level I.

Long-term outcome of low contact stress total knee arthroplasty with different mobile bearing designs

PURPOSE

to evaluate the differences in clinical outcome and survivorship of three different mobile bearings for total knee arthroplasty.

METHODS

a retrospective study was conducted in 60 patients (53 females, 7 males, mean age: 68 years and 5 months) each submitted to total knee replacement using one of the three different mobile bearings of the LCS system (Depuy Johnson & Johnson, Warsaw, IN). The diagnosis was knee osteoarthritis in 57 cases and rheumatoid arthritis in three cases. Three different groups of 20 cases each were identified: total knee arthroplasties with mobile menisci (group 1); total knee arthroplasties with the rotating platform (group 2); and total knee arthroplasties with the anteroposterior glide platform (group 3). As regards the component fixation, 33 implants were cementless, three were cemented, and in 24 only the tibial component was cemented. The patella was not replaced.

RESULTS

although the duration of follow-up differed between the three groups, the clinical and radiological results at final follow-up showed no revision of femoral and/or tibial components for mechanical or septic reasons, and no signs of impending failure. One meniscal bearing, showing polyethylene wear after 17 years, was successfully replaced.

CONCLUSIONS

the present retrospective study confirmed the long-term effectiveness of knee implants with mobile bearings, in which the congruity of the surfaces makes it possible to overcome the problem of high contact stresses that may result in polyethylene wear and osteolysis; at the same time, these implants eliminate constraint forces thereby reducing the risk of mechanical loosening.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.