Cemented or cementless total knee arthroplasty? - Comparative results of 200 cases at a minimum follow-up of 11 years

Interference fit of cementless tibial implants and the initial mechanical environment: A micro-CT and DVC study

During cementless total knee arthroplasty (TKA), an overlap between the resected tibia and the implant's geometry, termed interference fit, is introduced to facilitate primary stability and direct bone-implant contact. However, little is known about the actual interference achieved and the resulting mechanical response in the surrounding cancellous bone. The aim of this study was (1) to experimentally quantify the actual interference achieved for a commercially available cementless tibial implant and (2) to assess its effect on the post-impaction cancellous bone strain. Seven human cadaveric tibiae were micro-CT scanned intact (23 µm/pixel), once prepared for TKA (46 µm/pixel) and following implantation (46 µm/pixel). The actual interference across the entire bone-implant interface was quantified and, via digital volume correlation, the compressive strains of bone in contact with the implant and at increasing distance, were extracted. An inhomogeneous actual interference was found across the implant pegs and keel (median ± std dev: 0.70 ± 0.27 mm), which was lower than the intended. Limited interference (0.02 ± 0.12 mm) was found directly under the baseplate, with immediate bone-baseplate contact of 54%. The induced compressive strains were related to the actual interference within 3.14 mm from the bone-implant interface (R2 = 0.269-0.450, p < 0.001), with higher compressive strains corresponding to higher interference, but not being related to the bone volume fraction. Clinical Significance: Insight is provided into the interaction between the variability of the resection and the resulting mechanical environment. A complex relationship is apparent, whereby the actual interference accounted for up to 45% of the variation in induced compressive strain magnitude.

The COVID-19 pandemic caused gender-specific declines in knee surgery rates in Sweden from 2020 to 2021

Purpose

Changes in knee surgery incidence are important factors for stakeholders and healthcare providers. The aim of this study was to examine trends and patterns in knee surgeries in Sweden from 2010 to 2022. The study focuses on gender-specific and overall rates of knee surgeries.

Methods

The analysis is based on a data set sourced from national healthcare records. The data was stratified based on surgical rates and categorized by gender, year and the specific knee arthroplasty technique used. We tracked year-to-year changes in surgical rates to identify overarching patterns. We used Poisson regression to predict future trends. Comparisons were made between various surgical subcategories, such as those with and without cement in knee arthroplasty surgeries.

Results

In 2010, the rate of knee surgeries per 100,000 person-years was 518.7 for males and 448.0 for females. These rates exhibited fluctuations over time, reaching their lowest point in 2020, attributed to the pandemic's disruption of elective procedures, with 386.4 surgeries per 100,000 males and 386.3 surgeries per 100,000 females. A resurgence was observed in 2022. The rates of primary knee arthroplasty increased, with a male rate of 106.2 and a female rate of 150.7 surgeries per 100,000 inhabitants in 2010, rising to 126.8 for males and 166.2 for females in 2022.

Conclusion

This comprehensive nationwide open-source data analysis of knee surgeries in Sweden shows that the COVID-19 pandemic significantly impacted knee surgery rates in Sweden, causing a notable decline in 2020, followed by a resurgence in 2022. Furthermore, while men had higher surgery rates than women, they experienced a larger decline in the incidence of knee surgeries compared to women. Understanding these trends is crucial for stakeholders and healthcare providers to improve resource allocation, address gender disparities, and maintain the resilience of surgical services in the face of disruptions.

Level of Evidence

Level III.

A Comparison of the Periprosthetic Fracture Rate of Cemented and Cementless Total Knee Arthroplasties: An Analysis of Data From the National Joint Registry

BACKGROUND

Periprosthetic fractures are serious complications of knee arthroplasty often requiring complex surgery. There is concern of increased periprosthetic fracture risk with cementless components given the reliance on interference fit for primary stability. It is unknown how the periprosthetic fracture risk compares between cemented and cementless total knee arthroplasties (TKAs).

METHODS

A total of 22,477 cemented and 22,477 cementless TKAs from the National Joint Registry and Hospital Episodes Statistics database were propensity score matched on patient and surgical factors. Cumulative periprosthetic fracture rates were calculated using Kaplan-Meier analyses and compared with Cox regressions. Subgroup analyses were performed in different age, body mass index, and sex groups.

RESULTS

The 3-month fracture rate in the cemented and cementless TKA groups were 0.02% and 0.04%, respectively. At 10 years, the cumulative fracture rate after cemented TKA was 1.2%, and after cementless was 1.4%. During the study period, there were no significant differences in fracture rates between cemented and cementless TKAs with a hazards ratio 1.14 (confidence interval 0.94 to 1.37, P = .20) at 10 years postoperatively. There were no significant differences in fracture rates between fixation types on subgroup analyses of sex, body mass index, and age groups. Female sex was a risk factor for fracture in both cemented (odds ratio 2.35, P < .001) and cementless TKAs (odds ratio 2.97, P < .001).

CONCLUSIONS

The periprosthetic fracture rates following cemented and cementless TKA surgery are low being approximately 1.2% and 1.4%, respectively at 10 years. There were no significant differences in periprosthetic fracture rates requiring readmission between cemented and cementless TKAs.

LEVEL OF EVIDENCE

III.

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.

Survivorship and complications of cementless compared to cemented posterior-stabilized total knee arthroplasties: A systematic review and meta-analysis

PURPOSE

Controversy exists on the best fixation for total knee arthroplasty (TKA). Non-cemented fixation has been theorized to improve patient outcomes and longevity of implantation but no study has focused on comparison between cemented or cementless posterior-stabilized implants despite being the most commonly or second most frequently utilized implant in most total knee replacement registries.

METHODS

Inclusion criteria with observational and interventional papers, and review articles that focused on patients with cementless and cemented PS TKAs were used to analyze outcomes such as implant survivorship, complication, or revision rates. Using a combination of keywords, a systematic search was performed on Medline (PubMed), Embase, and Cochrane Library for Meta-Analysis.

RESULTS

When using the specified criteria, only 8 studies were selected for full-text analysis and meta-analysis after eliminating screening duplicates, titles, and abstracts without full-text access. These eight studies contain 1652 patients, 693 in the non-cemented Group, and 959 in the cemented total knee prosthesis Group. The meta-analysis revealed the advantage of cementless fixation over cemented fixation in implant survivorship, with 0.6% and 2.6% of aseptic loosening in each Group. The cumulative survival at 12 years was 97.4% for the cementless Group and 89.2% for the cemented Group. The subgroup with a stem showed a positive outcome for cementless fixation over cemented fixation regarding implant survivorship. No differences between the cemented and cementless TKAs were observed in patient-reported outcomes, revision rates, or radiolucent line development.

CONCLUSION

We observed comparable rates for cemented and cementless posterior-stabilized TKAs over a medium-term follow-up period.

24-Year-Old Patient with Klippel-Trenaunay Syndrome Underwent Cementless Robotic Cruciate-Retaining TKA: A Case Report

CASE

A 24-year-old man with Klippel-Trenaunay syndrome (KTS) presented with severe knee osteoarthritis unresponsive to conservative measures. Owing to end-stage, debilitating arthritic symptoms, surgery was pursued. Careful preoperative, multidisciplinary planning/treatment included magnetic resonance imaging to characterize the venous malformations throughout the right lower extremity, preoperative sclerotherapy, sirolimus, and robotic-assisted cementless total knee arthroplasty (TKA).

CONCLUSION

Cementless robotic-assisted TKA with selective patellar resurfacing can be a viable option for young KTS patients with severe osteoarthritis when a meticulous multidisciplinary approach, including sclerotherapy and advanced imaging, is undertaken to analyze vascular abnormalities, minimize surgical risks, preserve bone stock, and optimize outcomes.

Cemented vs. Cementless Fixation in Primary Knee Replacement: A Narrative Review

Knee osteoarthritis (OA) is one of the leading causes of disability around the globe. Osteoarthritis is mainly considered a disease affecting the elderly. However, more and more studies show that sports overuse, obesity, or congenital disorders can initiate a pathologic cascade that leads to OA changes in the younger population. Nevertheless, OA mostly affects the elderly, and with increasing life expectancy, the disease will develop in more and more individuals. To date, the golden standard in the treatment of the end-stage of the disease is total joint replacement (TJR), which restores painless knee motion and function. One of the weakest elements in TJR is its bonding with the bone, which can be achieved by bonding material, such as poly methyl-methacrylate (PMMA), or by cementless fixation supported by bone ingrowth onto the endoprosthesis surface. Each technique has its advantages; however, the most important factor is the revision rate and survivor time. In the past, numerous articles were published regarding TJR revision rate, but no consensus has been established yet. In this review, we focused on a comparison of cemented and cementless total knee replacement surgeries. We introduced PICO rules, including population, intervention, comparison and outcomes of TJR in a PubMed search. We identified 783 articles published between 2010 and 2023, out of which we included 14 in our review. Our review reveals that there is no universally prescribed approach to fixate knee prostheses. The determination of the most suitable method necessitates an individualized decision-making process involving the active participation and informed consent of each patient.

Long-term clinical and radiological outcome of a cementless titanium-coated total knee arthroplasty system

INTRODUCTION

To ensure a high-quality standard, it is important to frequently evaluate different prostheses models to avoid prostheses with high failure rates. Thus, the aim of the study was to evaluate the long-term outcome of the uncemented titanium-coated total knee arthroplasty (TKA) system (Advanced Coated System (ACS) III, Implantcast, GERMANY). We hypothesized that the ACS III would have a similar performance as other cemented TKA systems.

MATERIALS AND METHODS

A total of 540 ACS III mobile-bearing knee joint prostheses were implanted in 495 patients. The visual analogue scale (VAS) score, Tegner activity score (TAS), knee society score (KSS), Western Ontario and McMaster (WOMAC) score, and the Short Form 12 (SF-12) score for the evaluation of quality of life (QoL) were taken after at least 9 years of follow-up. In addition, we measured range of motion (ROM) and assessed potential sex differences. In addition, the survival analysis was calculated at a median follow-up of 16.7 years.

RESULTS

At the final follow-up, 142 patients had died, and 38 had been lost to follow-up. The rate of revision-free implant survival at 16.7 years was 90.0% (95% CI 87.1-92.2%) and the rate of infection-free survival was 97.0% (IQR 95.2-98.2%). The reasons for revision surgery were aseptic loosening (32.9%), followed by infection (27.1%), inlay exchange (15.9%), and periprosthetic fractures (5.7%). At the clinical follow-up visit, the mean VAS score was 1.9 ± 1.9, the median TAS was 3 (IQR 2-4), and the mean KSS for pain and function were 83.5 ± 15.3 and 67.5 ± 25.2, respectively. The mean WOMAC score was 81.1 ± 14.9, and the median SF-12 scores for physical and mental health were 36.9 (IQR 29.8-45.1) and 55.8 (IQR 46.2-61.0), respectively. The mean knee flexion was 102.0° ± 15.4°. Male patients had better clinical outcome scores than female patients [SF-12 mental health score, p = 0.037; SF-12 physical health score, p = 0.032; KSS pain score (p < 0.001), and KSS functional score (p < 0.001)].

CONCLUSION

The ACS III TKA system is a suitable option for the treatment of end-stage osteoarthritis of the knee joint because of its adequate long-term survival. Our findings are in line with published data on similar TKA systems that have shown favourable clinical scores in males.

LEVEL OF EVIDENCE

Level III-Retrospective cohort study.

Cemented total knee arthroplasty provides greater knee range of motion at 2 years than cementless technique

INTRODUCTION

Optimal fixation method between cemented, cementless, and hybrid techniques for total knee arthroplasty (TKA) is still debated. The purpose of this study is to evaluate the clinical outcomes of patients undergoing cemented versus cementless TKA.

METHODS

We reviewed 168 patients who underwent a primary TKA at a single academic institution between January 2015 and June 2017. Patients were categorized into cemented (n = 80) or cementless (n = 88) groups. Only patients with greater than or equal to 2-year follow-up were included in the study. Multivariate regressions were performed to analyze the relationship between the surgical fixation technique and the clinical outcomes.

RESULTS

There were no differences in demographics or baseline operative characteristics between the two groups. The cemented group had fewer manipulations under anesthesia (MUA) (4 vs. 15, p = 0.01), longer intraoperative tourniquet times (101.30 vs. 93.55 min, p = 0.02), and increased knee range of motion (ROM) at final follow-up (111.48 vs. 103.75°, p = 0.02) compared to the cementless group.

DISCUSSION AND CONCLUSION

Both cemented and cementless component fixation are viable options for (TKA). This study found that patients who underwent a cemented TKA required fewer MUA's and had greater final ROM compared to patients undergoing cementless TKA. Additional research is required regarding cementless and cemented fixation. We believe that the choice of which fixation technique to use ultimately comes down to patient characteristics and surgeon preference.

The sensitivity of the stiffness and thickness of a titanium inlay in a cementless PEEK femoral component to the micromotions and bone strain energy density

Polyetheretherketone (PEEK) has been proposed as alternative material for total knee arthroplasty implants due to its low stiffness, which may reduce stress-shielding. In cementless fixation, a proper primary fixation is required for long-term fixation. Previous research showed that the lower stiffness of a cementless PEEK femoral component results in larger micromotions at the implant-bone interface compared to a cobalt-chrome femoral component. A titanium inlay on the PEEK implant surface may improve the primary fixation while maintaining the favourable stiffness properties. Therefore, the effect of thickness and stiffness of a titanium inlay on the primary fixation and stress-shielding was investigated. A finite element model of the femur and femoral component was created with five titanium inlay variants. The micromotions and strain energy density (SED) were quantified as outcome measures. The distal thin - proximal thick variant showed the largest resulting micromotions (51.2 µm). Relative to the all-PEEK femoral component, the addition of a titanium inlay reduced the micromotions with 30 % to 40 % without considerably affecting the stress-shielding capacity (strain energy difference of 6 % to 10 %). Differences in micromotions (43.0-51.2 µm) and SED between the variants were relatively small. In conclusion, the addition of a titanium inlay could lead to a reduction of the micromotions without substantially affecting the SED distribution.

Highlighting the Advantages and Benefits of Non-NSAID Treatment After Total Knee Arthroplasty: A Cross-sectional Study

BACKGROUND/AIM

Osteoarthritis is one of the most common degenerative conditions that causes pain, stiffness, and decreased functionality. The management of knee osteoarthritis necessitates collaboration among specialists from different disciplines, considering the primary clinical manifestations and functional level of the disease. The aim of this study was to highlight the disparities in postoperative outcomes between knee arthroplasty procedures with and without non-steroidal anti-inflammatory drugs (NSAIDs). The study specifically focuses on the immediate advantages and outcomes observed at the 6-month milestone.

PATIENTS AND METHODS

This study followed 713 patients who were randomly divided into two groups: a group that did not receive non-steroidal anti-inflammatory drugs (N-NSAIDs) consisting of 394 patients, and a group that received non-steroidal anti-inflammatory drugs (NSAIDs) comprising 319 patients. The study spanned a duration of 5 years (2018-2022), with patients being followed and evaluated for up to 6 months after the surgery.

RESULTS

It was observed that, from a therapeutic standpoint, the use of injectable treatments decreased. Significantly better differences were recorded in the N-NSAIDs group regarding return to pre-osteoarthritis activities at 6 months and reduced or absent night pain at 3 months (p<0.05).

CONCLUSION

Statistically significant improvements were observed in the N-NSAIDs group concerning the ability to resume pre-osteoarthritis activities within 6 months, as well as a reduction or absence of nighttime pain within 3 months.

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.

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.

Patient-reported outcomes following cemented versus cementless primary total knee arthroplasty: a comparative analysis based on propensity score matching

BACKGROUND

Existing studies of patient-reported outcomes (PRO) following total knee arthroplasty (TKA) based on fixation methods (cemented vs cementless) are limited to single centers with small sample sizes. Using multicentered data,, we compared baseline and early post-operative global and condition-specific PROs between patients undergoing cemented versus cementless TKA.

METHODS

With PROs prospectively collected through Comparative Effectiveness Pulmonary Embolism Prevention After Hip and Knee Replacement (PEPPER) trial (ClinicalTrials.gov: NCT02810704), we examined pre- and post-operative (1, 3, and 6-months) outcomes in 5,961 patients undergoing primary TKA enrolled by 28 medical centers between December 2016 and August 2021. Outcomes included the short-form of the Knee Injury and Osteoarthritis Outcome Score (KOOS-Jr.), the Patient-Reported Outcomes Measurement Information System Physical Health (PROMIS-PH), and the Numeric Pain Rating Scale (NPRS). To minimize selection bias, we performed a 1-to-1 propensity score matched analysis to assess relative pre- to post-operative change in outcomes within and between cemented and cementless TKA groups.

RESULTS

With greater than 90% follow-up, significant pre to- post-operative improvements were observed in both groups. At 6 months, the cemented TKA group achieved a 3.3 point (55% of the Minimum Clinically Important Difference) greater improvement in the mean KOOS-Jr. (95%CI: 0.36, 6.30; P = 0.028) than did the cementless group with no significant between-group differences in PROMIS-PH and NPRS.

CONCLUSIONS

In a large cohort of primary TKAs, patients with cemented fixation reported early incremental benefit in KOOS-Jr. over those with cementless TKA. Future studies are warranted to capture longer follow-up of PROs.

The mid-term survival of cemented, uncemented, and hybrid fixation of the ACS mobile bearing total knee arthroplasty

Background

Till today, Cemented Fixation in Total Knee Arthroplasty (TKA) is significantly more used than Hybrid or Uncemented Fixation. The purpose of this study was to compare Cemented, Uncemented and Hybrid Fixation of the ACS Mobile Bearing TKA at Mid-term follow-up.

Methods

This study was an extended data report of our prospective single-center, single-blinded randomized controlled clinical trial comprising 105 patients. The primary outcome was survival at five years of follow-up calculated by Kaplan-Meier and Log-rank test. The secondary outcome was function based on patient-reported outcome measures (PROMs).

Results

Eighty-three patients were included, of which 25 belonged into group A (Cemented), 28 in group B (Uncemented), and 30 in group C (Hybrid). Mean follow-up was 5.8 ± 0.7 (range 5-7) years. The 5-year survival rates were 96.8% (95%CI: 90.5; 100) in the Cemented group, 94.2% (95%CI: 86.4; 100) in the Uncemented group, and 93.8% (95%CI: 85.4; 100) in the Hybrid group for revision for any reason (p = 0.80). Functional outcome was similar among the groups.

Conclusion

In our cohort of ACS Mobile Bearing TKA, there was no difference between Cemented, Uncemented, and Hybrid Fixation with regard to survival and function at Mid-term follow-up.

Trial registration

Dutch Trial Register (NTR3893), 2013-03-12.

Level of evidence

II.

Cemented Total Knee Arthroplasty Shows Less Blood Loss but a Higher Rate of Aseptic Loosening Compared With Cementless Fixation: An Updated Meta-Analysis of Comparative Studies

BACKGROUND

The aim of this study was to update the current evidence on functional outcomes, complications, and reoperation rates between cemented and cementless total knee arthroplasty (TKA) by evaluating comparative studies published over the past 15 years.

METHODS

The PubMed, MEDLINE, Scopus, and the Cochrane Central databases were used to search keywords and a total of 18 studies were included. Random and fixed effect models were used for the meta-analysis of pooled mean differences (MDs) and odds ratios (ORs).

RESULTS

A total of 5,222 patients were identified with a mean age of 64.4 ± 9.4 and 63 ± 8.6 years for the cemented and cementless TKA groups, respectively. The mean follow-up was 107.9 ± 30 and 104.3 ± 10 months for the cemented and cementless TKA groups, respectively. Cemented TKA showed a significantly greater postoperative Knee Society Score (MD = -0.95, 95% CI [-1.57, 0.33], P = .003) and range of motion (MD = -1.09, 95% CI [-1.88, -0.29], P = .0007), but no differences in other outcome scores were found. The incidence of periprosthetic joint infection, radiolucent lines, instability, and polyethylene wear was also comparable. Cemented TKA showed less perioperative blood loss (SMD = -438.41, 95% CI [-541.69, -35.14], P < .0001) but a higher rate of manipulation under anesthesia (OR = 3.39, 95% CI [1.64, 6.99], P = .001) and aseptic loosening (OR = 1.62, 95% CI [1.09, 2.41], P = .02) than cementless TKA. No differences were found in terms of the reoperation rate.

CONCLUSION

When cemented and cementless fixations are compared in primary TKA, comparable functional outcomes and reoperation rates can be achieved. Cemented TKA showed less blood loss but a higher rate of manipulation under anesthesia and aseptic loosening.

Micro-CT scan optimisation for mechanical loading of tibia with titanium tibial tray: A digital volume correlation zero strain error analysis

Primary stability of press-fit tibial trays is achieved by introducing an interference fit between bone and implant. The internal cancellous bone strains induced during this process and during loading have yet to be quantified experimentally. Advancements in large-gantry micro-CT imaging and digital volume correlation (DVC) allow quantification of such strains. However, before undertaking such a test, experimental requirements and DVC performance need to be examined, particularly considering the presence of a large orthopaedic implant (tibial tray). The aim of this study was to assess the DVC zero-strain accuracy (mean absolute error: MAER) and precision (standard deviation of error: SDER) on a cadaveric human tibia implanted with a titanium press-fit tray across four plausible scanning configurations, using a cabinet micro-CT system (Nikon XT H 225 ST). These varied in rotation step and resulting scanning time (106 min vs. 66 min), presence or absence of a 2 mm-thick aluminium cylinder for mechanical testing, and X-ray tube voltage (150 kVp vs. 215 kVp). One proximal tibia was implanted and micro-CT scanned (42 μm/pixel), with repeated scanning and specimen repositioning in between. DVC (DaVis, LaVision, direct correlation) was performed on nine cubic volumes of interest (VOIs: 13.4 mm-side) and across the entire proximal tibia. Strain errors were comparable across the four scanning configurations and sufficiently low for assessing bone within its elastic region in VOIs (MAER=223-540 με; SDER=88-261 με) and at organ level (MAER=536 με; SDER=473 με). Whilst the investigated experimental conditions, including a large titanium implant, present added complexity for DVC analysis, scans of sufficient quality can be achieved, reaching a compromise between the DVC requirements and the wanted application. The approach used for choosing the X-ray source settings considering the transmitted X-ray signal intensity and source power, is also discussed.

No effect of fixation type on early and late mortality after total knee arthroplasty: a Dutch arthroplasty register study

PURPOSE

Postoperative mortality is commonly reported as outcome measurement after total knee arthroplasty (TKA). Mortality might be influenced by multiple factors including cementation of the prosthesis. Until now, the influence of cementation on early and late mortality after TKA is unknown. The aim of the present study was to determine the effect of fixation on early and late mortality after primary TKA.

METHODS

All patients in the Dutch Arthroplasty Register (LROI) with a primary TKA for osteoarthritis were eligible for inclusion. Data collected from 2007 to 2014 with follow-up until January 2020 were used. Survival analysis was performed by using Kaplan-Meier and Cox survival analysis to determine the mortality rate according to fixation. Adjustments were made for age at time of surgery, gender, American Society of Anaesthesiologists class, and year of surgery.

RESULTS

In total 108,687 TKA were included for analysis, which comprised 95,857 cemented, 6,140 cementless and 6,690 hybrid TKA. The early and late mortality rate in cemented TKA was statistically not different compared to cementless or hybrid TKA at 30 days, 31-90 days, 91 days-1 year and 1-5 years. The hazard ratio at 30 days was 1.05 (CI 0.49-2.25) for hybrid fixation, and 1.46 (CI 0.74-2.90) for cementless fixation compared to cemented fixation. The 1-5 years hazard ratio was 1.06 (CI 0.96-1.17) and 0.97 (CI 0.87-1.08), respectively.

CONCLUSION

Based on register data, method of fixation does not influence early mortality after primary TKA. This suggests that there is no preferred fixation technique for primary TKA based on the mortality rates.

LEVEL OF EVIDENCE

IV.

Is standard total knee arthroplasty with lateral femoral overhanging a cause of anterior knee pain? A randomized controlled trial

Introduction: Anterior knee pain (AKP) may persist after total knee arthroplasty (TKA), even if well aligned and stable, and is reported in up to 30% of patients, leading to patient dissatisfaction. The gender-specific knee prostheses have been designed to reduce femoral component overhanging in females and improve patient satisfaction. The purpose of this study was to determine AKP between gender-specific knee prosthesis and unisex knee prosthesis following minimally invasive surgery (MIS) TKA with patellar resurfacing. Methods: This study was a randomized trial comparing a gender-specific vs. unisex knee prosthesis in females with knee osteoarthritis. Follow-up occurred at 6 weeks, 3 months, 6 months, 1 year, and 2 years. Pre- and postoperative AKP were measured at each follow-up. Intraoperative lateral overhanging of the femoral component and patellar tracking were also measured and compared between the two groups. Results: Sixty females were recruited; 30 underwent gender-specific knee prosthesis (Gp1) and 30 underwent unisex knee prosthesis (Gp2). No patients were lost to follow-up. The incidence rates of AKP and visual analog scale AKP pain scores at 2 years were 7 vs. 7% (p = 1.00) and 0.95 ± 0.31 (0–1) points vs. 1.10 ± 0.28 (0–1) points (p = 0.68) for gender and unisex prostheses, respectively. Patellar tilt and patellar shift were similar between the two groups. Patellar tilt and patellar shift were 2.56° ± 2.03 (0–8) vs. 2.67° ± 2.35 (0–9) (p = 0.46) and 1.25 ± 1.09 (0–3.2) mm vs. 1.15 ± 0.97 (0–2.9) mm (p = 0.34) for Gp1 and Gp2, respectively. Mean lateral femoral overhanging was 0.23 ± 0.63 mm (range: 1–2 mm, Gp1) vs. 1.57 ± 1.36 mm (range: 1–3 mm, Gp2) (p ≤ 0.001). Conclusion: Both types of prostheses had similar incidence rates of AKP, VAS scores for AKP. Lateral femoral overhanging of ≤ 3 mm was not the cause of AKP.

Highlighting the advantages and benefits of cementless total knee arthroplasty (Review)

In the field of orthopedic surgery, cemented total knee arthroplasty (TKA) is considered to be one of the gold standards. However, there are categories of patients (i.e., obese and morbidly obese patients, younger than 65 years old) among whom cemented TKA has however a high failure rate. Moreover, the frequency of using uncemented TKA is increasing due to the potential benefits of long-term biological fixation, being an innovative field that addresses a new generation orthopedic surgical treatment which is more suitable for young patients who have good bone quality (good to very good, in terms of density). The survival rates and functional results of the latest generation of cementless TKAs may be similar to functional results and survival rates of cemented prosthesis. In conclusion, this review-type article can be considered a powerful database, extremely informative, dense, and focused on the topic mentioned above, in the interest of all medical professionals and all interested individuals.

[Comparison of effectiveness of total knee arthroplasty with tantalum monoblock tibial component and cemented tibial plateau prosthesis in patients of different ages]

Objective

To investigate the difference of total knee arthroplasty (TKA) with tantalum monoblock tibial component (TMT) and cemented tibial plateau prosthesis in patients of different ages.

Methods

The clinical data of 248 patients (392 knees) who underwent primary TKA between May 2014 and May 2019 and met the selection criteria were retrospectively analyzed. There were 54 males (98 knees) and 194 females (294 knees). Of the 122 patients (183 knees), less than 65 years old, 52 (75 knees, group A1) were treated with TMT and 70 (108 knees, group B1) were treated with cemented tibial plateau prosthesis; of the 126 patients (209 knees), more than 65 years old, 57 (82 knees, group A2) were treated with TMT and 69 (127 knees, group B2) were treated with cemented tibial plateau prosthesis. The baseline data of patients, perioperative indicators [hemoglobin (Hb), hematocrit (Hct), total blood loss, unilateral operation time], effectiveness evaluation indicators [Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, visual analogue scale (VAS) score, Knee Society Scoring System (KSS) score, active flexion and extension range of motion (ROM) of the knee joint], complications, and imaging indicators [tibial prosthesis varus angle (β angle), tibial prosthesis posterior slope angle (δ angle), tibio-femoral angle, occurrence of radiolucent line, prosthesis survival rate] were recorded and compared.

Results

There was no significant difference in gender, age, height, weight, body mass index, Kellgren-Lawrence grading, the length of hospital stay, and follow-up time between groups A1, B1 and groups A2, B2 ( P>0.05). The unilateral operation time in groups A1 and A2 was significantly shorter than that in the corresponding groups B1 and B2 ( P<0.05). There was no significant difference in differences of pre- and post-operative Hb and Hct and total blood loss between groups A1, B1 and groups A2, B2 ( P>0.05). There was no significant difference in preoperative effectiveness evaluation indicators between groups A1, B1 and groups A2, B2 ( P>0.05). There were significant differences in the differences of pre- and post-operative WOMAC activity and pain scores, KSS function and pain scores, and VAS scores between groups A1 and B1 ( P<0.05); there was no significant difference in WOMAC stiffness score and ROM ( P>0.05). There was no significant difference in the above indicators between groups A2 and B2 ( P>0.05). There was no significant difference in the incidence of complications (2.7% vs 6.5%, 3.7% vs 3.1%) and prosthesis survival rate (100% vs 97.2%, 100% vs 99.2%) between groups A1, B1 and groups A2, B2 ( P>0.05). During follow-up, there was no significant difference in β angle, δ angle, and tibio-femoral angle between groups A1, B1 and groups A2, B2 ( P>0.05). In the evaluation of knee X-ray radiolucent line, 2 knees of group A1 and 2 knees of group A2 had radiolucent line at prosthesis-bone interface immediately after operation, and the radiolucent line was gradually filled by new bone, without new radiolucent line. During follow-up, 1 knee of group B1 and 1 knee of group B2 had prosthesis-bone interface radiolucent line, without radiolucent line widening or prosthesis loosening.

Conclusion

TMT is recommended in patients less than 65 years old, and the two types of prostheses are available for patients nore than 65 years old. However, the long-term effectiveness of the two types of prosthesis in patients of different ages needs further follow-up.

A Matched Comparison of the Long-Term Outcomes of Cemented and Cementless Total Knee Replacements: An Analysis from the National Joint Registry of England, Wales, Northern Ireland and the Isle of Man

BACKGROUND

Total knee replacements (TKRs) can be implanted with or without the use of cement. It is currently uncertain how cemented and cementless TKRs compare overall and in different age groups of the population in the long term.

METHODS

The National Joint Registry collects information on knee replacements inserted in England, Wales, Northern Ireland, and the Isle of Man and was linked for multiple confounders to the National Health Service Hospital Episode Statistics database. With use of propensity score matching techniques, 44,954 cemented and cementless TKRs were compared. Regression models were used to compare the outcomes of revision, reoperation, and mortality both overall and in different age strata.

RESULTS

The 10-year implant survival rate with revision as the end point for cemented and cementless TKRs was 96.0% and 95.5%, respectively (hazard ratio [HR] = 1.14; p = 0.01). The 10-year survival rate with reoperation as the end point was 82.7% and 81.4%, respectively (HR = 1.08; p = 0.001). The rate of revision for pain was higher for cementless TKRs (0.5% [cemented] compared with 0.7% [cementless]; p = 0.002), but the rate of revision for infection was lower (0.7% [cemented] compared with 0.5% [cementless]; p = 0.003). No significant interactions with age existed for the outcomes of revision (p = 0.24), reoperation (p = 0.30), or mortality (p = 0.58).

CONCLUSIONS

We found that matched cemented and cementless TKRs both have 10-year implant survival rates of >95%. Cementless TKRs had a higher revision rate (absolute difference, 0.5%) and reoperation rate (absolute difference, 1.3%). The rate of revision for infection was lower in the cementless group, although the rate of revision for pain was higher. Age did not significantly affect the relative performances.

LEVEL OF EVIDENCE

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

Comparable mid-term revision rates of primary cemented and cementless total knee arthroplasties in 201,211 cases in the Dutch Arthroplasty Register (2007-2017)

PURPOSE

Long-term failure of total knee arthroplasty (TKA) is mostly due to loosening of the prosthesis. In this study, the short- and mid-term revision rates of cemented vs cementless TKAs were investigated. Comparable short- and mid-term survival rates of both fixation methods were expected.

METHODS

Data on all cemented and cementless TKAs performed between 2007 and 2017 were retrieved from the Dutch Arthroplasty Register. The cumulative crude incidence of revision of cemented and cementless TKA was calculated. Death was considered a competing risk. Revision rates were compared using multivariable Cox proportional hazard regression analysis. The associations between fixation method and type of revision or reason for revision were tested using logistic regression analyses.

RESULTS

In total, 190,651 (94.8%) cemented and 10,560 (5.3%) cementless TKAs were evaluated. Both groups had comparable case characteristics. Cemented TKAs were inserted more often in cases with previous knee surgery compared to cementless TKAs (32% vs 27%). The cumulative incidence of revision after 9 years was 5.5% (CI 5.3-5.6%) for cemented and 5.8% (CI 5.2-6.4%) for cementless TKAs (p = 0.2). Cementless TKAs were more often revised due to loosening of the tibial (27% vs 18%; p < 0.001) or the femoral component (7% vs 5%; p = 0.005) than cemented TKAs. Cemented TKAs were more often revised due to infection (17% vs 9%; p = 0.004) than cementless TKAs.

CONCLUSION

In conclusion, cemented and cementless TKAs have comparable short- and mid-term revision rates based on a nationwide register study.

LEVEL OF EVIDENCE

III.

Cementing technique for total knee arthroplasty in cadavers using a pastry bone cement

Background

In cemented primary total knee arthroplasty (TKA), aseptic loosening remains a major cause for failure. Cementing techniques and characteristics of a chosen cement play a key role for good fixation and implant survival. A pastry bone cement was developed to facilitate the cement preparation and to rule out most of preparation-associated application errors. The pastry bone cement was compared to a conventional polymethyl methacrylate cement in a TKA setting.

Methods

Standardized implantations of total knee endoprostheses were performed in bilateral knee cadavers to investigate handling properties, variables of cement application, working time, and temperature development. Mechanical aspects and cementation quality were assessed by pull-out trials and microscopic interface analysis.

Results

Both cements expressed similar characteristics during preparation and application, only the curing time of the pastry cement was about 3 min longer and the temperature peak was lower. Fractures of the conventional cement specimens differed from the pastry cement specimens in the tibial part, while no differences were found in the femoral part. Penetration depth of the pastry cement was similar (tibia) or deeper (femur) compared to the conventional cement.

Conclusions

The pastry cement facilitates the feasibility of cemented TKA. The pre-clinical tests indicate that the pastry bone cement fulfills the requirements for bone cement in the field of knee arthroplasty. A clinical trial is needed to further investigate the approach and ensure patient safety.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02436-z.

Excellent mid-term follow-up for a new 3D-printed cementless total knee arthroplasty

AIMS

Cementless total knee arthroplasty (TKA) offers the potential for strong biological fixation compared with cemented TKA where fixation is achieved by the mechanical integration of the cement. Few mid-term results are available for newer cementless TKA designs, which have used additive manufacturing (3D printing). The aim of this study was to present mid-term clinical outcomes and implant survivorship of the cementless Stryker Triathlon Tritanium TKA.

METHODS

This was a single institution registry review of prospectively gathered data from 341 cementless Triathlon Tritanium TKAs at four to 6.8 years follow-up. Outcomes were determined by comparing pre- and postoperative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) scores, and pre- and postoperative 12-item Veterans RAND/Short Form Health Survey (VR/SF-12) scores. Aseptic loosening and revision for any reason were the endpoints which were used to determine survivorship at five years.

RESULTS

At mid-term follow-up, the mean KOOS JR score improved significantly from 33.14 (0 t0 85, standard deviation (SD) 21.88) preoperatively to 84.12 (15.94 to 100, SD 20.51) postoperatively (p < 0.001), the mean VR/SF-12 scores improved significantly from physical health (PH), 31.21 (SD 5.32; 23.99 to 56.77) preoperatively to 42.62 (SD 10.72; 19.38 to 56.82) postoperatively (p < 0.001) and the mental health (MH), 38.15 (SD 8.17; 19.06 to 60.75) preoperatively to 55.09 (SD 9.64; 19.06 to 66.98) postoperatively (p < 0.001). A total of 11 revisions were undertaken, with an overall revision rate of 2.94%, including five for periprosthetic joint infection (1.34%), three for loosening (0.80%), two for instability (0.53%), and one for pain (0.27%). The overall survivorship was 97.06% and survivorship for aseptic loosening as the endpoint was 98.40%, with a 99.5% survivorship of the 3D-printed tibial component.

CONCLUSION

This 3D-printed cementless total knee system shows excellent survivorship at mid-term follow-up. This design and the ability to obtain cementless fixation offers promise for excellent long-term durability. Cite this article: Bone Joint J 2021;103-B(6 Supple A):32-37.

Are The Applications of Tranexamic Acid in Reverse Hybrid Total Knee Arthroplasty (TKA) The Same as Those in Fully Cemented TKA?: A Randomized Controlled Trial

INTRODUCTION

Traditional fully cemented prosthesis for total knee arthroplasty (TKA) has many disadvantages. Current studies have shown that the effects of mixed fixation TKA are the same as or even better than those of fully cemented TKA. We aimed to compare the total blood loss (TBL) in the two fixation types of TKA and the hemostatic effects of different doses of tranexamic acid (TXA) for reverse hybrid TKA.

METHODS

From September 2018 to November 2020, 233 patients with knee osteoarthritis undergoing unilateral TKA were randomly divided into four groups: groups 1 and 2: fully cemented TKA + intra-articular injection (IAI) of either 1 g TXA (n = 54) or 2 g TXA (n = 60); groups 3 and 4: reverse hybrid TKA + IAI of either 1 g TXA (n = 56) or 2 g TXA (n = 63). All patients were administered intravenous drip of TXA (20 mg/kg) as the basic drug. Perioperative and follow-up data of all patients were compared.

RESULTS

The TBL in groups 1, 2, and 3 was higher than that in group 4 (P < 0.0001). The TBL in group 1 was significantly less than that in group 3 (P < 0.05). Although there was no significant difference in blood transfusion demand among the four groups (P > 0.05), the number of anemic patients who did not meet the standard of blood transfusion in group 4 decreased significantly (P < 0.0001). There was no significant difference in pain, function or thrombotic complications among all patients.

CONCLUSION

The TBL in reverse hybrid TKA is larger than in fully cemented TKA. For reverse hybrid TKA, the hemostatic effect of TXA with 2 g of IAI was significantly better than with 1 g. Although this method does not reduce the need for blood transfusion, it can significantly reduce the incidence of postoperative anemia.

A comprehensive comparison between cementless and cemented fixation in the total knee arthroplasty: an updated systematic review and meta-analysis

BACKGROUND

Whether the cement should be used in the total knee arthroplasty (TKA) was still in controversy. This meta-analysis was performed to compare the efficacy of two kinds of fixation.

METHODS

Randomized controlled trials (RCTs), prospective/retrospective observational studies from PubMed (on 2019 September), EMBASE (on 2019 September), and the Cochrane Central Register of Controlled Trials (CENTRAL) and Web of Science (on 2019 September) were searched. Only studies followed more than 2 years was included for the review. The PRISMA guidelines and Cochrane Handbook were adopted to assess the quality of the results reported in included studies to ensure that the results of our meta-analysis were reliable and veritable. The continuous and dichotomous outcomes were collected in a standard form, and the data were analyzed by Review Manager 5.3 software. Finally, the results were presented in the Forest plots.

RESULTS

Twenty-six studies involving 2369 patients in cementless TKA and 2654 patients in cemented TKA were included. The rate of revision was not significantly different in two groups (p = 0.55). More than eight reasons caused revision were found in our study, the aseptic loosing was the most common, followed by the periprosthetic joint infection (PJI), neither was significantly different (p = 0.88 and 0.45, respectively). While significantly better long-term functional recovery was found in cementless TKA in terms of Knee Society Function Score (p = 0.004) and manipulation under anesthesia (p = 0.007).

CONCLUSION

Cementless fixation did not decrease the rate of revision after the total knee arthroplasty compared with the cemented fixation, while the long-term functional recovery was significantly better in the cementless group.

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

A matched cohort study between cementless TKA and cemented TKA shows a reduction in tourniquet time and manipulation rate

Introduction

Cementless total knee arthroplasty (TKA) is now becoming more acceptable with the advent of newer ongrowth constructs and better initial fixation. It has been proposed that cementless TKA may save OR time and result in a lower incidence of manipulation. This study was designed to assess the difference between cemented and cementless TKA.

Methods

Our hospital statistician performed a matched cohort analysis between 127 cementless TKAs and 127 cemented TKRs performed by a single surgeon. Patients were matched on age and BMI. Mean tourniquet time between the cemented and cementless TKAs was assessed as well as the rate of manipulation between these groups. Of note, a tourniquet was routinely used in both the cementless and cemented cohorts to reduce confounding bias.

Results

A total of 127 cementless TKAs with a mean age of 60.8 years and mean BMI 32.2 were compared to 127 cemented TKAs with a mean age of 61.5 years and mean BMI of 32.2 at an average follow-up of 2.0 years. There was a statistically significant reduction in tourniquet time in the cementless TKA cohort at 45.7 min compared to the cemented TKA cohort at 54.8 min (p = 0.001). Estimated blood loss was similar in both the cementless (179.5 ml) and cemented (196 ml) cohorts (p = 0.3) and postoperative outcomes, including UCLA score.In addition, the cementless TKA cohort had a manipulation rate of 0% compared to 3.1% for the cemented TKA group (p = 0.044).

Discussion and conclusion

While cementless and cemented TKA have shown similar PROMs and survivorship, we demonstrated a significant reduction in tourniquet time with cementless TKRs, with similar estimated blood loss, and a lower incidence of manipulation with cementless TKRs in this matched cohort study. The increased cost of a cementless implant may be negated if one considers the cost savings of not using cement, the cost savings of not performing manipulations, and the shorter operative time.

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.

Angular limit for coronal joint deformity correction using intramedullary guidance in total knee arthroplasty. A pilot study

INTRODUCTION

Post-operative misalignment of the lower limb mechanical axis following total knee arthroplasty (TKA) is thought to be associated with clinical failure. In a balanced knee, a neutral global mechanical axis following the use of intra-medullary (IM) guidance does not necessarily imply a horizontal TKA joint line. Using femoral and tibial axes separately would be more accurate in evaluating TKA alignment. Thus, the aim of the study is to define a pre-operative mechanical tibial and/or femoral angle threshold value for post-operative optimal alignment correction using IM guides.

METHODS

This single-center prospective continuous pilot study included 50 patients treated with a TKA for primitive osteoarthritis. Femoral and tibial cuts were performed using intramedullary (IM) guide. Three angles were calculated and analyzed pre and post-operatively on standing antero-posterior views using long-leg radiographs: femorotibial angle (FTA), mechanical femoral angle (MFA), and mechanical tibial angle (MTA). Statistical analysis was performed for the whole sample and for the three following FTA subgroups; normo-axial, varus and valgus.

RESULTS

The pre-operative MTA is the only parameter for which a threshold value was observed; when pre-operative MTA exceeded the value of 94°, an optimal correction might not be obtained post-operatively.

DISCUSSION

Our results suggest that the bony correction obtained via IM guiding depends exclusively on the primary deformation of the tibia. In cases of a varus of more than 94°, the IM guide was found to yield sub-optimal corrections. Thus, other solutions need to be investigated.

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.

Convincing long-term results independent from the postoperative leg alignment following cementless total knee arthroplasty

BACKGROUND

Cementless primary total knee arthroplasty shows numerous advantages compared with cemented implants (e.g., shorter operation time, preservation of the bone stock). Up to now an increasing number of clinical long-term studies exist. Despite this fact, there is no evidence about the influence of the postoperative leg alignment on the results of cementless knee arthroplasty. There is no work on the clinical outcome of the specific implant, which was used in this study (VANGUARD®, ZimmerBiomet). The purpose of this study was to assess the clinical and radiological long-term results after cementless knee arthroplasty in relation to the postoperative mechanical leg alignment.

METHODS

Clinical and radiological results were retrospectively assessed in 83 patients at 10.3 years (ranging from 9.6 to 11.8 years) after implantation. Hip-knee-ankle angle (HKA) was measured, and the patients were separated into a corrected (HKA between three degrees of varus and three degrees of valgus, n = 60) and a varus/valgus (HKA > 3° of varus and valgus, n = 23) group.

RESULTS

Up to the time of the clinical follow-up, three out of 83 patients already underwent a revision surgery due to a deep infection (3.6%). Tegner-Lysholm Knee scale was 89.1 in the corrected group and 88.8 in the varus/valgus group (p = .94). The mean Knee Injury and Osteoarthritis Outcome score (KOOS) was 81.2 in the corrected group and 82.4 in the varus/valgus group (p = .63).

CONCLUSIONS

Results of this study showed convincing clinical and radiological results after primary cementless knee arthroplasty. Under- or overcorrected postoperative mechanical leg alignments did not influence the long-term clinical results.

Titanium Porous Coating Using 3D Direct Energy Deposition (DED) Printing for Cementless TKA Implants: Does It Induce Chronic Inflammation?

Because of the recent technological advances, the cementless total knee arthroplasty (TKA) implant showed satisfactory implant survival rate. Newly developed 3D printing direct energy deposition (DED) has superior resistance to abrasion as compared to traditional methods. However, there is still concern about the mechanical stability and the risk of osteolysis by the titanium (Ti) nanoparticles. Therefore, in this work, we investigated whether DED Ti-coated cobalt-chrome (CoCr) alloys induce chronic inflammation reactions through in vitro and in vivo models. We studied three types of implant surfaces (smooth, sand-blasted, and DED Ti-coated) to compare their inflammatory reaction. We conducted the in vitro effect of specimens using the cell counting kit-8 (CCK-8) assay and an inflammatory cytokine assay. Subsequently, in vivo analysis of the immune profiling, cytokine assay, and histomorphometric evaluation using C57BL/6 mice were performed. There were no significant differences in the CCK-8 assay, the cytokine assay, and the immune profiling assay. Moreover, there were no difference for semi-quantitative histomorphometry analysis at 4 and 8 weeks among the sham, smooth, and DED Ti-coated samples. These results suggest that DED Ti-coated printing technique do not induce chronic inflammation both in vitro and in vivo. It has biocompatibility for being used as a surface coating of TKA implant.

Cementless versus Cemented Fixation in Total Knee Arthroplasty: Usage, Costs, and Complications during the Inpatient Period

Cemented fixation has been the gold standard in total knee arthroplasty (TKA). However, with younger and more active patients requiring TKA, cementless (press-fit) fixation has sparked renewed interest. Therefore, we investigated differences in (1) patient demographics, (2) inpatient costs, (3) short-term complications, and (4) discharge disposition between patients who underwent TKA with cemented and cementless fixation. The National Inpatient Sample database was queried for TKA patients with cement or cementless fixation between October 1 and December 31, 2015. Primary outcomes of interest included complications, length of stay (LOS), discharge disposition, and inpatient costs. Student's t-test and chi-square analysis were used to assess continuous and categorical data, respectively. Multivariable analysis evaluated the effects of fixation type on the continuous and categorical dependent variables. Patients who received cementless fixation were more often younger (63.5 vs. 65.9 years), male (47.4 vs. 40.3%), Black (10.7 vs. 7.7%), from the Northeast census region (29.1 vs. 17.1%), and under private insurance (49.2 vs. 40.3%; p < 0.001 for all). Cementless fixation involved higher inpatient hospital costs (US$17,357 vs. US$16,888) and charges (US$67,366 vs. US$64,190; p < 0.001 for both), lower mean LOS (2.63 vs. 2.71 days; p < 0.001), and higher odds of being discharged to home (odds ratio = 1.99; p = 0.002). This study revisited the outcomes of TKA with cementless fixation and demonstrated higher inpatient charges and costs, shorter mean LOS, and higher odds of being discharged home. Future studies should investigate patient outcomes and complications past the inpatient period, evaluate long-term survivorship and failure rates, and implement a prospective study design.

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.

Midterm Results of Cementless Total Knee Arthroplasty: A Retrospective Case Series

Background:

There is an ongoing debate about whether to use cementless or cemented fixation for Total Knee Arthroplasty (TKA).

Objective:

The study aimed to assess midterm survivorship of the Vanguard cementless system, and to demonstrate the utility of the Bone Hardness Test (BHT) for the selection of cementless fixation TKA.

Methods:

From September 2009 through November 2014, 123 total knee arthroplasties were completed, with cementless Vanguard Cruciate Retaining TKA in 110 knees (102 patients) and cemented Vanguard in 13 cases (12 patients). Implant fixation was based on intraoperative assessment of posterior cruciate ligament stability, bone quality, and BHT. All patients with a cementless Vanguard implant were eligible for this retrospective study. Preoperative and postoperative Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index were obtained. Standardized standing anteroposterior and lateral radiographs were taken.

Results:

Three patients (4 TKAs) were lost to follow-up. The mean follow-up time was 5.5 ± 1.4 years. All scores significantly improved postoperatively. No radiographic failures were observed. Five-year implant survival, with revision of any component for any reason as an endpoint, was 97.2% (95% confidence interval, 91.7 - 99.1%). Five-year survival with revision for aseptic loosening was 100%. Only one knee required revision due to an isolated unrelated bearing exchange, and two additional knees required secondary resurfacing of the patella for retropatellar pain.

Conclusion:

Good midterm results were obtained with the cementless Vanguard Cruciate Retaining TKA for the treatment of osteoarthritis. The Bone Hardness Test appears to be an effective way to determine the selection of cementless TKA.