Cementless Total Knee Arthroplasty is Associated With Early Aseptic Loosening in a Large National Database

The Reverse Dorr: Preoperative radiographic evaluation of bone quality correlates to bone mineral density in total knee arthroplasty

Background

There has been an increase in cementless total knee arthroplasty (TKA) across the country. Although radiographic classification systems of the knee exist, these algorithms have not been correlated to bone mineral density (BMD). We aimed to correlate radiographic measurements of the knee with preoperative BMD and develop a model predictive of osteopenia.

Materials and methods

We prospectively enrolled 100 patients, scheduled to undergo elective TKA, to obtain a preoperative dual energy x-ray absorptiometry (DEXA) scan. Four independent surgeons measured cortical indices of the knee on preoperative radiographs and correlated these ratios with local BMD. Intraclass correlations (ICC) were used to assess interobserver reliability and Pearson correlation coefficients (PCC) to describe the strength of relationship between BMD and radiographic ratios. A "Reverse Dorr" model was created to evaluate the ratio of the distal femur cortical indices. Logistic regression was used to predict the odds of having osteopenia.

Results

We found several cortical ratios of the knee correlated with bone mineral density, but the lateral radiograph had the highest correlation. All measurements showed, at a minimum, fair interobserver reliability with most achieving an ICC >0.81. The proximal femur, distal femur ratio, "Reverse Dorr" model, was found to be a strong predictor of osteopenia with an ROC of 0.7335.

Conclusions

This radiographic assessment demonstrates that cortical thickness of the knee is correlated with bone mineral density-most notably on the lateral radiograph. Utilization of the "Reverse Dorr" model was strongly predictive of osteopenia and may help guide implant selection.

Bisphosphonate Use in Patients Who Have Osteoporosis Does Not Increase the Risk of Periprosthetic Fracture Following Total Knee Arthroplasty

BACKGROUND

The purpose of this study was to evaluate the effect of preoperative bisphosphonate use in patients who have osteoporosis on the risk of complications following primary total knee arthroplasty (TKA).

METHODS

An administrative claims database was queried for patients who have osteoporosis undergoing primary TKA between 2010 and 2019 with a minimum of 2-year follow-up. Bisphosphonate-naive patients and bisphosphonate users, defined as patients who had a continuous prescription for bisphosphonates for a minimum of 6 months preoperatively, were matched 1:1 based on age, sex, and comorbidity burden. Patients undergoing nonelective TKA on chronic glucocorticoid therapy or receiving any other pharmacologic treatment for osteoporosis were excluded. The final cohort included 21,058 matched pairs of patients. The incidence of postoperative complications was identified via International Classification of Disease coding and compared between matched groups. A subgroup analysis was performed to examine outcomes among patients who underwent cemented and cementless TKA.

RESULTS

There was no difference in the incidence of periprosthetic fracture on univariate (0.7 versus 0.8%, P = 0.068) or multivariate testing (OR [odds ratio]: 1.24, 95% confidence interval [0.99 to 1.56]; P = 0.060). Bisphosphonate users were statistically less likely to undergo all-cause revision TKA at 2 years (OR: 0.84 [0.72 to 0.97]; P = 0.021). Patients who had osteoporosis were found to have an increased risk of periprosthetic fracture when TKA was performed with cementless implants (1.6 versus 0.4%; P = 0.033). However, when treated with bisphosphonates, patients who have osteoporosis demonstrated equivalent fracture rates regardless of implant type (1.3 versus 1.0%; P = 1.000).

CONCLUSIONS

While bisphosphonate use in patients who have osteoporosis did not decrease the risk of periprosthetic fracture, it did significantly lower the incidence of all-cause revision at 2 years, although the difference identified was small. Consideration should be given to performing cemented TKA in patients who have untreated osteoporosis, given the higher rate of periprosthetic fracture when cementless implants were utilized.

Osteoporosis May Not Be an Absolute Contraindication for Cementless Total Knee Arthroplasty

BACKGROUND

Cementless total knee arthroplasty (TKA) has received growing interest, particularly in younger populations, due to potential long-term survivability and improved bone preservation. Poor bone stock, as seen in osteoporosis, is considered a contraindication for this technique. This study evaluated whether osteoporotic patients < 75 years undergoing cementless TKA demonstrate similar: 1) implant-related complications, 2) medical complications, 3) readmission rates, and 4) 3-year implant survivability.

METHODS

A retrospective query of a national administrative claims database was performed between 2010 and 2022 for patients less than or equal to 75 years old who have osteoporosis and underwent primary TKA. Osteoporotic patients were divided into cementless and cemented cohorts, and propensity scores were matched based on age, sex, obesity, and the Charlson Comorbidity Index. Matching produced 7,923 patients (1,321 uncemented, 6,602 cemented). Multivariate logistic regressions evaluated the following outcomes: 90-day and 2-year implant-related complications, 90-day postoperative medical complications, and 90-day readmissions. Kaplan-Meier survival analysis was conducted to assess 3-year all-cause revision implant survivability. The significance threshold was set to P < 0.01 to minimize type 1 bias.

RESULTS

There were no statistically significant differences in implant-related complications, medical complications, readmissions, and lengths of stay between cementless and cemented TKA groups. Kaplan-Meier analysis demonstrated statistically similar 3-year survivability between cohorts (cemented: 97.6%, confidence interval 96.6 to 98.5; cementless: 97.2%, confidence interval 96.7 to 97.7; P = 0.472).

CONCLUSIONS

Patients who have osteoporosis have equivalent medical and implant-related complications as well as 3-year implant survival following cementless TKA compared with a cemented technique. Our results support cementless TKA as a viable option for patients < 75 years, regardless of prior diagnosis of osteoporosis. Intraoperative decisions regarding bone quality are still necessary to discriminate between those who are candidates for cementless TKA with those who are not.

LEVEL OF EVIDENCE

Level III, Retrospective cohort study.

Uncemented Total Knee Arthroplasty in the State of Michigan has Higher Rates of Revision Through 5-Year Follow-Up

BACKGROUND

While cemented total knee arthroplasty (TKA) is considered the gold standard, uncemented designs are gaining popularity, especially in young men who are at higher risk of cemented failure. Assessing this growth's impact, the Michigan Arthroplasty Registry Collaborative Quality Initiative analyzed adoption rates of uncemented TKA and the effect of fixation technique on revision rates with the goal of assessing the revision rates and survivorship at five years of cemented versus uncemented TKA to further classify which patients may be more ideal candidates for cementless fixation.

METHODS

The Michigan Arthroplasty Registry Collaborative Quality Initiative data from 2017 to 2022 was analyzed to determine the survivorship of cemented versus uncemented TKAs. Descriptive statistics, demographics, and implant type were collected. Cumulative percent revision (CPR) was calculated based on the fixation method. The primary endpoint was time for the first revision. Kaplan-Meier survival curves were compared. Subanalyses were performed based on age, sex, body mass index, and implant type. Confidence intervals were set to 95%.

RESULTS

The registry query yielded 147,838 TKAs. There were 18,523 (12.5%) uncemented TKAs. Uncemented TKA use increased yearly from 2017 to 2022 in all groups. Uncemented TKA had higher CPR through five years at all time points versus cemented (3.65 versus 3.19%, P < 0.0001). Uncemented TKA performed worse in both men and women (P < 0.01, P < 0.01). Unexpectedly, men < 55 years had higher CPR at all time points for the four most used implants (P < 0.05).

CONCLUSIONS

The use of uncemented TKA has grown in Michigan across all patient subgroups. Uncemented TKAs had an overall higher risk of revision compared to cemented TKAs. The poorer outcomes appeared consistent across sex, age, and implant type. Younger men who are often preferred for uncemented fixation had higher failure rates. This study suggests that surgeons should be mindful of revision rates and patient selection when moving to uncemented TKA.

Comparison of medium- and long-term total knee arthroplasty follow-up with or without tourniquet

BACKGROUND

Applying non-tourniquet technology in total knee arthroplasty (TKA) is becoming increasingly popular. However, there is no consensus on its effect on the service life of knee prostheses. This study examined the effect of tourniquet use on cement penetration and radiolucent line (RLL) to assess whether the use of tournique in TKA affects prosthesis survival.

METHODS

We retrospectively analyzed 166 patients admitted to our hospital between January 1, 2014, and June 1, 2015, who met the inclusion criteria. The patients were divided into the tourniquet (80 cases) and non-tourniquet groups (86 cases) according to whether a tourniquet was used during the operation. We compared the preoperative data and related complications between both groups. Hip-knee-ankle (HKA), medial proximal tibial angle (MPTA) and the penetration depth of bone cement on the osteotomy surface was measured according to postoperative imaging data. Furthermore, the probability of occurrence of radio-clear lines around the prosthesis was observed.

RESULTS

A total of 166 patients were enrolled with a mean age of 68.52 ± 4.74 years and a mean follow-up time of 105.67 ± 5.98 years. No significant demographic differences were observed between the two groups (P > 0.05). Revision surgery was performed for one patient in each group due to aseptic loosening of the prosthesis. The preoperative and postoperative knee association function scores (HSS), knee range of motion, HKA, and MPTA between the two groups did not differ significantly (P > 0.05). In the lateral observation of zone femur 3A and the average observation area of the femur, the penetration depth of the osteotomy surface were significantly different between the two groups (P < 0.05). The incidence of radiolucent lines differed slightly between both groups in different observation areas,but the revision rate did not differ significantly between the two groups (P > 0.05).

CONCLUSION

In the long term, TKA without tournique use can achieve clinical effects comparable to the use of tourniquet in many aspects, such as prosthesis stability, prosthesis survival rate, reoperations rate, knee range of motion, and knee functionality.

Cementless fixation in total joint arthroplasty: Factors impacting osseointegration

•The success of cementless fixation in TJA depends on a multitude of factors including biological, mechanical, implant, surgical, and material properties.•Biologic fixation has become the primary mode of fixation for the majority of primary total hip arthroplasty (THA) surgeries done today in the United States (US) due to its low complication rate and superior longevity compared to cemented fixation.•Cementless fixation has yet to gain wider acceptance in total knee arthroplasty (TKA) and hip hemiarthroplasty due to several factors including host bone quality, implant design, and surgical technique.•Understanding a) the properties of the different biomaterials, b) the bone-implant interface characteristics of the different ingrowth and ongrowth surfaces, and c) the various factors that affect osseointegration can lead to:i)appropriate choice of implants for individual patients with consequent increase in revision-free survival, andii)the development of new techniques that can reduce the risk of aseptic loosening.

Aseptic Tibial Loosening Is Associated With Thickness of the Cement: A Radiographic Case-Control Study

BACKGROUND

The cementation technique is crucial for achieving adequate fixation and optimal survivorship in total knee arthroplasty (TKA). The thickness of the cement at the tibial bone-implant surface may be related to aseptic tibial loosening. However, to date, no studies have demonstrated a direct association between cement thickness and rates of aseptic tibial loosening.

METHODS

We performed a retrospective review to identify 28,327 primary cemented TKAs with at least 2 years of follow-up at an academic health system from 2013 to 2021. A total of 115 cases underwent revision surgery for aseptic tibial loosening. Cases where the implant was recalled specifically for loosening (n = 23) were excluded. The remaining 92 aseptic tibial loosening cases were 2:1 propensity score matched and implant matched to control patients who did not have tibial loosening. There were two independent reviewers who then measured the thickness of the cement interface in 10 locations along the bone-implant interface from initial postoperative radiographs. The averages of the reviewers' measurements were calculated and then compared using independent t-tests.

RESULTS

Aseptic tibial loosening cases involving implant A tibial baseplate (n = 75) had significantly thinner cement interfaces than matched controls at all the 10 locations measured. Aseptic loosening cases involving implant B (n = 17) also displayed a thinner cement interface than matched controls in all locations, but this result was only statistically significant at the medial baseplate, medial keel, lateral keel, anterior keel, and posterior baseplate.

CONCLUSIONS

In two widely used TKA systems, tibial aseptic loosening was associated with significantly thinner cement interfaces when compared to propensity-matched controls in two different implant types. Further prospective studies are needed to identify the optimal keel preparation and design as well as minimal cement interface thickness to avoid implant loosening.

LEVEL OF EVIDENCE

III.

Robotic assistance improves success of cementless component fixation in one total knee arthroplasty system

INTRODUCTION

New cementless implant designs in total knee arthroplasty (TKA) have begun to shift the longstanding practice of cemented fixation. With aseptic loosening a leading cause for revision of cementless implants, initial osteointegration is critical for component survivorship. Robotic-assisted TKA (RA-TKA) has shown promising results in recent literature at improving component accuracy. The current study aims to evaluate if robotic assistance affects the success of cementless fixation in primary TKA.

METHODS

445 cementless primary TKA components from one manufacturer implanted by five surgeons between June 2018 and October 2022 were retrospectively reviewed. Those with minimum one-year follow-up were analyzed. Femoral and tibial components were reviewed separately and grouped based on whether manual or RA-TKA from the same manufacturer was performed. Fisher's exact test was used to analyze if aseptic loosening rates were different between the two techniques.

RESULTS

373 (82%) cementless components from a single knee system were included. 146 femoral and 103 tibial components were implanted using RA-TKA, while 63 femoral and 61 tibial components were implanted manually. At a mean follow-up of 18 months (range, 12 to 51 months), successful fixation was achieved in 96.2% of all components. No femoral components from either group were revised due to aseptic loosening. Four manually implanted vs. no robotically assisted tibial components were revised due to aseptic loosening (6.6% vs 0.0%; P = 0.038).

CONCLUSION

The performance of modern cementless femoral components was excellent with or without robotic assistance, however RA-TKA improved the survivorship of the same system's cementless tibial component.

LEVEL OF EVIDENCE

Level III.

Cementless Total Knee Arthroplasty: A Resurgence-Who, When, Where, and How?

BACKGROUND

Total knee arthroplasty (TKA) is one of the most common procedures in orthopaedics, but there is still debate over the optimal fixation method for long-term durability: cement versus cementless bone ingrowth. Recent improvements in implant materials and technology have offered the possibility of cementless TKA to change clinical practice with durable, stable biological fixation of the implants, improved operative efficiency, and optimal long-term results, particularly in younger and more active patients.

METHODS

This symposium evaluated the history of cementless TKA, the recent resurgence, and appropriate patient selection, as well as the historical and modern-generation outcomes of each implant (tibia, femur, and patella). Additionally, surgical technique pearls to assist in reliable, reproducible outcomes were detailed.

RESULTS

Historically, cemented fixation has been the gold standard for TKA. However, cementless fixation is increasing in prevalence in the United States and globally, with equivalent or improved results demonstrated in appropriately selected patients.

CONCLUSIONS

Cementless TKA provides durable biologic fixation and successful long-term results with improved operating room efficiency. Cementless TKA may be broadly utilized in appropriately selected patients, with intraoperative care taken to perform meticulous bone cuts to promote appropriate bony contact and biologic fixation.

Cementless Total Knee Arthroplasty: A State-of-the-Art Review

» The demographic profile of candidates for total knee arthroplasty (TKA) is shifting toward younger and more active individuals.» While cemented fixation remains the gold standard in TKA, the interest is growing in exploring cementless fixation as a potentially more durable alternative.» Advances in manufacturing technologies are enhancing the prospects for superior long-term biological fixation.» Current research indicates that intermediate to long-term outcomes of modern cementless TKA designs are comparable with traditional cemented designs.» The selection of appropriate patients is critical to the success of cementless fixation techniques in TKA.» There is a need for high-quality research to better understand the potential differences and relative benefits of cemented vs. cementless TKA systems.

Cemented Versus Cementless Femoral Fixation for Total Hip Arthroplasty Following Femoral Neck Fracture in Patients Aged 65 and Older

BACKGROUND

Femoral neck fractures are common in individuals over 65, necessitating quick mobilization for the best outcomes. There's ongoing debate about the optimal femoral component fixation method in total hip arthroplasty (THA) for these fractures. Recent U.S. data shows a preference for cementless techniques in over 93% of primary THAs. Nonetheless, cemented fixation might offer advantages like fewer revisions, reduced periprosthetic fractures, lesser thigh pain, and enhanced long-term implant survival for those above 65. This study compares cementless and cemented fixation methods in THA, focusing on postoperative complications in patients aged 65 and older.

METHODS

We analyzed a national database to identify patients aged 65+ who underwent primary THA for femoral neck fractures between 2016 and 2021, using either cementless (n = 2,842) or cemented (n = 1,124) techniques. A 1:1 propensity-matched analysis was conducted to balance variables such as age, sex, and comorbidities, resulting in two equally sized groups (n = 1,124 each). We evaluated outcomes like infection, venous thromboembolism (VTE), wound issues, dislocation, periprosthetic fracture, etc., at 90 days, 1 year, and 2 years post-surgery. A P-value < 05 indicated statistical significance.

RESULTS

The cemented group initially consisted of older individuals, more females, and higher comorbidity rates. Both groups had similar infection and wound complication rates, and aseptic loosening. The cemented group, however, had lower periprosthetic fracture rates (2.5 versus 4.4%, P = .02) and higher VTE rates (2.9 versus 1.2%, P = .01) at 90 days. After 1 and 2 years, the cementless group experienced more aseptic revision surgeries.

CONCLUSIONS

This study, using a large, national database and propensity-matched cohorts, indicates that cemented femoral component fixation in THA leads to fewer periprosthetic fractures and aseptic revisions, but a higher VTE risk. Fixation type choice should consider various factors, including age, sex, comorbidities, bone quality, and surgical expertise. This data can inform surgeons in their decision-making process.

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.