Socioeconomic issues and demographics of total knee arthroplasty revision

How Does the Physician Patient Fare After Primary Total Hip and Knee Arthroplasty?

Background

Physician patients requiring surgery present with occupational risks and personality traits that may affect outcomes. This study compared implant survivorship, complications, and clinical outcomes of physicians undergoing primary total hip arthroplasty (THA) or total knee arthroplasty (TKA).

Methods

A retrospective review of our institutional total joint registry identified 185 physicians undergoing primary THA (n = 94) or TKA (n = 91). Physicians were matched 1:2 with nonphysician controls according to age, sex, body mass index, joint (hip or knee), and surgical year. Physician type (medical, n = 132 vs surgical, n = 53) subanalysis was performed. Implant survivorship was assessed via Kaplan-Meier methods. Clinical outcomes were evaluated by Harris hip scores and Knee Society Scores. Mean follow-up was 5 years.

Results

There was no significant difference in 5-year implant survivorship free of any reoperation (P > .5) or any revision (P > .2) between physician and nonphysician patients after THA and TKA. Similarly, the 90-day complication risk was not significantly different after THA or TKA (P = 1.0 for both). Physicians and nonphysicians demonstrated similar improvement in Harris hip scores (P = .6) and Knee Society Scores (P = .4). When comparing physician types, there was no difference in implant survivorship (P > .4), complications (P > .6), or patient reported outcomes (P > .1).

Conclusions

Physician patients have similar implant survivorship, complications, and clinical outcomes when compared to nonphysicians after primary THA and TKA. Physicians should feel reassured that their profession does not appear to increase risks when undergoing lower extremity total joint arthroplasty.

Racial and Socioeconomic Disparities in Risk and Reason for Revision in Total Joint Arthroplasty

INTRODUCTION

Data regarding racial/ethnic and socioeconomic differences in revision total hip arthroplasty (rTHA) and revision total knee arthroplasty (rTKA) have been inconsistent. This study examined racial/ethnic and socioeconomic disparities in comorbidity-adjusted risk and reason for rTHA and rTKA.

METHODS

Patients who underwent rTHA or rTKA between 2006 and 2014 in the National Inpatient Sample were identified. Multivariable logistic regression models adjusted for payer status, hospital geographic setting, and patient characteristics (age, sex, and Elixhauser Comorbidity Index) were used to examine the effect of race/ethnicity and socioeconomic status on trends in annual risk of rTHA/rTKA and causes of rTHA/rTKA.

RESULTS

Black patients were less likely to undergo rTHA and more likely to undergo rTKA while Hispanic patients were more likely to undergo rTHA and less likely to undergo rTKA ( P < 0.001 for all) compared with White patients. Patients residing in areas of lower income quartiles were more likely to undergo rTHA and rTKA compared with those in the highest quartile ( P < 0.001), and these disparities persisted and widened over time. Black, Hispanic, and Asian patients were less likely to undergo rTHA/rTKA because of dislocation compared with White patients ( P < 0.001 for all). Patients from areas of lower income quartiles were more likely to undergo rTHA because of septic complications and less likely to require both rTHA and rTKA because of mechanical complications ( P < 0.001 for all).

DISCUSSION

Racial/ethnic and socioeconomic disparities exist in risk and cause of rTHA and rTKA. Increasing awareness and a focus on minimizing variability in hospital quality may help mitigate these disparities.

The Benefit in Patient-Reported Outcomes After Total Knee Arthroplasty was Comparable Across Income Quartiles

BACKGROUND

Few studies have assessed how socioeconomic status (SES) influences patient-reported outcomes (PROMs) after total knee arthroplasty (TKA). This study evaluated the impact of patient median ZIP code income levels on PROMs after TKA.

METHODS

We retrospectively reviewed patients at our institution undergoing primary, unilateral TKA from 2017 to 2020. Patients who did not have one-year postoperative PROMs were excluded. Patients were stratified based on the quartile of their home ZIP code median income from United States Census Bureau data. There were 1,267 patients included: 98 in quartile 1 (median income ≤ $46,308) (7.7%); 126 in quartile 2 (median income $46,309-$57,848) (10.0%); 194 in quartile 3 (median income $57,849-$74,011) (15.7%); and 849 in quartile 4 (median income ≥ $74,012) (66.4%). We collected baseline demographic data, 2-year outcomes, and PROMs preoperatively, as well as at 12 weeks and one year, postoperatively.

RESULTS

The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement was significantly higher in quartile 4 preoperatively (P < .001), 12 weeks postoperatively (P < .001), and one year postoperatively (P < .001). There were no significant differences in delta improvements of Knee Injury and Osteoarthritis Outcome Score for Joint Replacement from preoperative to 12 weeks or one year postoperatively. There were no significant differences in lengths of stay, discharge dispositions, readmissions, or revisions.

CONCLUSION

Patients from lower income areas have slightly worse knee function preoperatively and worse outcomes following TKA. However, improvements in PROMs throughout the first year postoperatively are similar across income quartiles, suggesting that patients from lower income quartiles achieve comparable therapeutic benefits from TKA.

LEVEL III EVIDENCE

Retrospective Cohort Study.

Association of Lumbar Degenerative Disease and Revision Rate following Total Knee Arthroplasty

Recently, a variety of studies have analyzed the potential correlation between lumbar degenerative disease (LDD) and inferior clinical outcomes after total hip arthroplasty. However, there has been limited data concerning the role of LDD as a risk factor for failure after total knee arthroplasty (TKA). The aim of our study was to determine: (1) what is the association of LDDs with TKA failure (all-cause revision) within 2 years of index arthroplasty and (2) if patients with LDD and lumbar fusion are at increased risk of TKA revision within 2 years compared with LDD patients without fusion. Data were collected from the Humana insurance database using the PearlDiver database from 2007 to 2017. To assess aim 1, patients were stratified into two groups based on a prior history of LDD (International Classification of Diseases [ICD]-9 or -10 diagnostic codes). To analyze aim 2, patients within the LDD cohort were stratified based on the presence of lumbar fusion (lumbar fusion Current Procedural Terminology code). All-cause revision rate was 3.4% among LDD patients versus 2.4% of patients with non-LDD (p < 0.001) at 2 years. Following multivariate analysis, LDD patients were at increased risk of all-cause revision surgery at 2 years (odds ratio [OR]: 1.361; 95% confidence interval [CI]: 1.238-1.498; p < 0.001) as well as aseptic loosening (OR: 1.533; 95% CI: 1.328-1.768; p < 0.001), periprosthetic joint infection (OR: 1.245; 95% CI: 1.129-1.373; p < 0.001), and periprosthetic fracture (OR: 1.521; 95% CI: 1.229-1.884; p < 0.001). Among LDD patients, patients who have a lumbar fusion had an all-cause revision rate of 5.0%, compared with 3.2% among LDD with no lumbar fusion patients at 2 years (p = 0.021). Following multivariate analysis, lumbar fusion patients were at increased risk of all-cause revision surgery (OR: 1.402; 95% CI: 1.362-1.445; p = 0.028), aseptic loosening (OR: 1.432; 95% CI: 1.376-1.489; p = 0.042), and periprosthetic fracture (OR: 1.302; 95% CI: 1.218-1.392; p = 0.037). Based on these findings, TKA candidates with preoperative LDD should be counseled that TKA outcome may be impaired by the coexistence of lumbar spine degenerative disease. This is Level III therapeutic study.

Are patient-reported outcomes the same following second-side surgery in primary hip and knee arthroplasty?

Aims

Up to one in five patients undergoing primary total hip (THA) and knee arthroplasty (TKA) require contralateral surgery. This is frequently performed as a staged procedure. This study aimed to determine if outcomes, as determined by the Oxford Hip Score (OHS) and Knee Score (OKS) differed following second-side surgery.

Methods

Over a five-year period all patients who underwent staged bilateral primary THA or TKA utilizing the same type of implants were studied. Eligible patients had both preoperative and one year Oxford scores and had their second procedure completed within a mean (2 SDs) of the primary surgery. Patient demographics, radiographs, and OHS and OKS were analyzed.

Results

A total of 236 patients met the inclusion criteria, of which 122 were THAs and 114 TKAs. The mean age was 66.5 years (SD 9.4), with a 2:1 female:male ratio. THAs showed similar significant improvements in outcomes following first- and second-side surgery, regardless of sex. In contrast for TKAs, although male patients demonstrated the same pattern as the THAs, female TKAs displayed significantly less improvement in both OKS and its pain component following second-side surgery.

Conclusion

Female patients undergoing second-side TKA showed less improvement in Oxford and pain scores compared to the first-side. This difference in outcome following second-side surgery did not apply to male patients undergoing TKA, or to either sex undergoing THA.

Cite this article: Bone Jt Open 2021;2(4):243–254.

Uncemented Tantalum Monoblock Tibial Fixation for Total Knee Arthroplasty in Patients Less Than 60 Years of Age: Mean 10-Year Follow-up

BACKGROUND

Although tibial component loosening has been considered a concern after total knee arthroplasty without cement, such implants have been used in younger patients because of the potential for ingrowth and preservation of bone stock. However, mid-term and long-term studies of modern uncemented implants are lacking. We previously reported promising prospective 5-year outcomes after using an uncemented porous tantalum tibial component in patients who underwent surgery before the age of 60 years. The purpose of this study was to determine clinical and radiographic implant survivorship at 10 years in this large series of young patients.

METHODS

The original cohort included 79 patients (96 knees) who were <60 years old at the time of surgery. All procedures were performed with an uncemented, posterior-stabilized femoral component and a porous tantalum monoblock tibial component by 1 high-volume arthroplasty surgeon at a single institution. Patients were followed prospectively. The Knee Society Score (KSS), radiographic findings, and any complications or revisions were recorded.

RESULTS

At the latest follow-up, 76% (60) of the 79 patients (74% [71] of the 96 knees) were available for evaluation or had undergone revision (n = 6); 7 patients had died with the implants in place, and 12 patients were lost to follow-up. The average follow-up for the available implants was 10 years (range, 8 to 12 years). There were no progressive radiolucencies on radiographic review. The mean functional KSS was 68 points (range, 0 to 100 points). All revisions were for reasons unrelated to tibial fixation: femoral component loosening (1), stiffness (1), pain and swelling (2), and instability (2). The all-cause revision rate was 6% (6 of 96 knees).

CONCLUSIONS

Uncemented porous tantalum monoblock tibial components provided reliable fixation, excellent radiographic findings, and satisfactory functional outcomes at a mean of 10 years postoperatively. We identified no cases of tibial component loosening. These promising clinical and radiographic results support the use of uncemented tibial components. Such implants may produce well-integrated, durable long-term constructs in young patients.

LEVEL OF EVIDENCE

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

Correlation of tibial bone defect shape with patient demographics following total knee revision

Background

Bone defects of the proximal tibia following revision total knee arthroplasty (TKA) are challenging to manage, but must be addressed to provide lasting stability. This paper will categorize tibial bone defects into shape groups and correlate resulting groups to patient demographic data.

Methods

Retrospective analysis of four hundred and four patients post revision TKA between January 2005 and February 2014 was conducted. One hundred and eighteen met the inclusion criteria and were subcategorized by defect shape on their post-operative lateral and anterior-posterior (AP) radiographs. The subgroups of defect shape were subsequently analyzed with Fisher's exact test and one way ANOVA.

Results

Trapezoidal shaped defects were the most common in both radiographic views, and the magnitude of the defect at the top joint line varied significantly amongst shape groups in both AP and lateral views. Trapezoid shaped defects were correlated with smaller defect top lengths in both views. There was no statistical correlation between defect shape BMI, TIV and reason for revision in lateral view. However, T-bilateral defect shapes were correlated with higher BMIs in AP view.

Conclusion

A volumetric classification system of tibial defects is necessary for preoperative planning in revision TKA. Common tibial bone defect shape groups were identified and analyzed in AP and lateral radiographs after revision TKA. Trapezoidal defects were the most common, and all other shapes followed a pattern of proximal enlargement tapering distally. Trapezoidal defects were smaller than other shapes and AP T-bilateral shaped defects were correlated with higher BMIs.

Evaluation of a multimodal pain therapy concept for chronic pain after total knee arthroplasty: a pilot study in 21 patients

Background

In spite of the improvement of many aspects around Total knee arthroplasty (TKA), there is still a group of 10% to 34% of patients who is not satisfied with the outcome. The therapy of chronic pain after TKA remains a medical challenge that requires an interdisciplinary therapy concept. The aim of this prospective pilot study was to evaluate the efficacy of a multimodal pain therapy in chronic complaints after TKA.

Methods

In a prospective cohort pilot study, we included patients with chronic pain after TKA who obtained in-patient care, especially multimodal pain therapy (MMPT), for at least 10 days. Essential elements of this therapy concept were physiotherapy, pain medication therapy, topical application of ketamine, local infiltration and Traditional Chinese Medicine. Patients with varying causes of complaints were excluded in advance. Before the start of the study all test persons were informed and gave their written consent. Moreover, each patient was examined and questioned at hospital admission, discharge and at its first as well as second follow-up. Additionally, knee joint mobility and stability were investigated at all examination times.

Results

From 03/07/2016 to 07/14/2016, 21 patients were included in the pilot study. 52% of the considered population were female (11 persons). The median age was 65 years (45–79 years) and the median stay in hospital amounted 9 days (8–14 days). The first follow-up was scheduled after six weeks (median: 38 days, 30–112 days) and the second one after six months (median: 8 months, 7–12 months). The number of patients of the first follow-up was 17 out of 21 (19% drop out). The drop out of the last follow-up accounted for 33%. All patients benefit from the presented applications and therapies with regard to pain, function and range of motion. Especially, during the period of in-patient treatment, nearly all patients have improved in all terms. However, during the first follow-up clear deteriorations occurred in all areas, which stagnated up to the second follow-up. The range of motion has even worsened slightly.

Conclusions

With the presented pilot study on multimodal in-patient therapy of chronic complaints due to TKA, the improvement of pain, function and mobility could be verified, especially during the stationary stay. Even though the results deteriorate during the follow-up period, they did never relapse to their initial level. In order to ensure an effective treatment, a clear diagnostic algorithm is essential, by which treatable causes, such as low-grade infections or loosenings, are safely excluded. Further prospective studies are necessary to obtain precise statements on prospects of success of our therapy plan.

Patient Attitudes Toward Orthopedic Surgeon Ownership of Related Ancillary Businesses

BACKGROUND

Physician ownership of businesses related to orthopedic surgery, such as surgery centers, has been criticized as potentially leading to misuse of health care resources. The purpose of this study was to determine patients' attitudes toward surgeon ownership of orthopedic-related businesses.

METHODS

We surveyed 280 consecutive patients at 2 centers regarding their attitudes toward surgeon ownership of orthopedic-related businesses using an anonymous questionnaire. Three surgeon ownership scenarios were presented: (1) owning a surgery center, (2) physical therapy (PT), and (3) imaging facilities (eg, Magnetic Resonance Imaging scanner).

RESULTS

Two hundred fourteen patients (76%) completed the questionnaire. The majority agreed that it is ethical for a surgeon to own a surgery center (73%), PT practice (77%), or imaging facility (77%). Most (>67%) indicated that their surgeon owning such a business would have no effect on the trust they have in their surgeon. Although >70% agreed that a surgeon in all 3 scenarios would make the same treatment decisions, many agreed that such surgeons might perform more surgery (47%), refer more patients to PT (61%), or order more imaging (58%). Patients favored surgeon autonomy, however, believing that surgeons should be allowed to own such businesses (78%). Eighty-five percent agreed that patients should be informed if their surgeon owns an orthopedic-related business.

CONCLUSION

Although patients express concern over and desire disclosure of surgeon ownership of orthopedic-related businesses, the majority believes that it is an ethical practice and feel comfortable receiving care at such a facility.

How are we addressing ligament balance in TKA? A literature review of revision etiology and technological advancement

Despite technological advances in operative technique and component materials, the total knee arthroplasty (TKA) revision burden, in the United States, has remained static for the past decade. In light of an anticipated exponential increase in annual surgical volume, it is important to thoroughly understand contemporary challenges associated with technologically driven TKA. This descriptive literature review harvested 69 relevant publications to extrapolate patient trends, benefits, costs, and complications associated with computer-assisted surgery, patient specific instrumentation, and intra-operative sensors. Due to additional charges, a steep learning curve, and questionable cost-effectiveness, widespread use of these systems has been limited. Intra-operative sensors are a relatively recent development, and have been shown to improve both soft-tissue balance and overall functional outcomes at a relatively low price and without disrupting operative workflow. The introduction of new technology into the operating suite should be considered carefully, especially with respect to combined clinically efficacy and cost.

Socioeconomically Disadvantaged CMS Beneficiaries Do Not Benefit From the Readmission Reduction Initiatives

We assessed the impact of minority and socioeconomic status on 30-day readmission rates after 3825 primary total hip arthroplasty (THA) and 3118 primary total knee arthroplasty (TKA) procedures. Minority patients had higher THA (7.4% vs 3.2%, P=0.001) and TKA (5.4% vs 3.7%, P<0.001) readmission rates. Low socioeconomic status was associated with higher THA (6.0% vs 3.1%, P<0.001) and TKA (6.3% vs 3.8%, P=0.02) readmission rates. Risk reduction initiatives were effective after TKA, but minority status and low socioeconomic status were still associated with higher 30-day readmission rates (4.6% vs 1.8%, P<0.01). Focused postoperative engagement for Centers for Medicare and Medicaid Services (CMS) beneficiaries less than 65 years of age may help reduce complications and 30-day readmissions.

Comparative Epidemiology of Revision Arthroplasty: Failed THA Poses Greater Clinical and Economic Burdens Than Failed TKA

BACKGROUND

Revision THA and TKA are growing and important clinical and economic challenges. Healthcare systems tend to combine revision joint replacement procedures into a single service line, and differences between revision THA and revision TKA remain incompletely characterized. These differences carry implications for guiding care and resource allocation. We therefore evaluated epidemiologic trends associated with revision THAs and TKAs.

QUESTIONS/PURPOSES

We sought to determine differences in (1) the number of patients undergoing revision TKA and THA and respective demographic trends; (2) differences in the indications for and types of revision TKA and THA; (3) differences in patient severity of illness scoring between THA and TKA; and (4) differences in resource utilization (including cost and length of stay [LOS]) between revision THA and TKA.

METHODS

The Nationwide Inpatient Sample (NIS) was used to evaluate 235,857 revision THAs and 301,718 revision TKAs between October 1, 2005 and December 31, 2010. Patient characteristics, procedure information, and resource utilization were compared across revision THAs and TKAs. A revision burden (ratio of number of revisions to total number of revision and primary surgeries) was calculated for hip and knee procedures. Severity of illness scoring and cost calculations were derived from the NIS. As our study was principally descriptive, statistical analyses generally were not performed; however, owing to the large sample size available to us through this NIS analysis, even small observed differences presented are likely to be highly statistically significant.

RESULTS

Revision TKAs increased by 39% (revision burden, 9.1%-9.6%) and THAs increased by 23% (revision burden, 15.4%-14.6%). Revision THAs were performed more often in older patients compared with revision TKAs. Periprosthetic joint infection (25%) and mechanical loosening (19%) were the most common reasons for revision TKA compared with dislocation (22%) and mechanical loosening (20%) for revision THA. Full (all-component) revision was more common in revision THAs (43%) than in TKAs (37%). Patients who underwent revision THA generally were sicker (> 50% major severity of illness score) than patients who underwent revision TKA (65% moderate severity of illness score). Mean LOS was longer for revision THAs than for TKAs. Mean hospitalization costs were slightly higher for revision THA (USD 24,697 +/- USD 40,489 [SD]) than revision TKA (USD 23,130 +/- USD 36,643 [SD]). Periprosthetic joint infection and periprosthetic fracture were associated with the greatest LOS and costs for revision THAs and TKAs.

CONCLUSIONS

These data could prove important for healthcare systems to appropriately allocate resources to hip and knee procedures: the revision burden for THA is 52% greater than for TKA, but revision TKAs are increasing at a faster rate. Likewise, the treating clinician should understand that while both revision THAs and TKAs bear significant clinical and economic costs, patients undergoing revision THA tend to be older, sicker, and have greater costs of care.

Association between household income and the outcome of arthroplasty: a register-based study of total hip and knee replacements

INTRODUCTION

Previous research findings regarding the association between the outcomes of total hip and knee arthroplasty and patients' socioeconomic status have been contradictory. Consequently, we wanted to analyse whether individual-level household income was associated with the risk of revision arthroplasty and whether the time span in days from the primary arthroplasty to the revision operation varied according to income quintile.

MATERIALS AND METHODS

All first total hip and knee arthroplasties performed due to primary osteoarthritis in Finland from 1998 to 2007 were included in the study. Cox proportional hazard regression modelling was applied in the analysis regarding the risk of revision after the primary operation, while Poisson regression modelling was applied in the analysis regarding differences in the time from the primary to the revision operation between income quintiles.

RESULTS

The relationship between household income and the risk of revision arthroplasty was not statistically significant. The relationship remained insignificant, even when age, sex, and other confounding factors were adjusted for or analyses concerned revision in short or long term. In both the total hip arthroplasty and knee arthroplasty populations, patients in the lowest income quintiles underwent revision surgery earlier than patients in the highest income groups, but this difference was not statistically significant.

CONCLUSION

The quality of arthroplasty as measured by the risk of revision does not seem to depend on patients' income quintile.

Lack of diversity in orthopaedic trials conducted in the United States

BACKGROUND

Several orthopaedic studies have suggested patient race and ethnicity to be important predictors of patient functional outcomes. This issue has also been emphasized by federal funding sources. However, the reporting of race and ethnicity has gained little attention in the orthopaedic literature. The objective of this study was to determine the percentage of orthopaedic randomized controlled clinical trials in the United States that included race and ethnicity data and to record the racial and ethnic distribution of patients enrolled in these trials.

METHODS

A systematic review of orthopaedic randomized controlled trials published from 2008 to 2011 was performed. The studies were identified through a manual search of thirty-two scientific journals, including all major orthopaedic journals as well as five leading medical journals. Only trials from the United States were included. The publication date, journal impact factor, orthopaedic subspecialty, ZIP code of the primary research site, number of enrolled patients, type of funding, and race and ethnicity of the study population were extracted from the identified studies.

RESULTS

A total of 158 randomized controlled trials with 37,625 enrolled patients matched the inclusion criteria. Only thirty-two studies (20.3%) included race or ethnicity with at least one descriptor. Government funding significantly increased the likelihood of reporting these factors (p &lt; 0.05). The percentages of Hispanic and African-American patients were extractable for studies with 7648 and 6591 enrolled patients, respectively. In those studies, 4.6% (352) of the patients were Hispanic and 6.2% (410) were African-American; these proportions were 3.5-fold and twofold lower, respectively, than those represented in the 2010 United States Census.

CONCLUSIONS

Few orthopaedic randomized controlled trials performed in the United States reported data on race or ethnicity. Among trials that did report demographic race or ethnicity data, the inclusion of minority patients was substantially lower than would be expected on the basis of census demographics. Failure to represent the true racial diversity may result in decreased generalizability of trial conclusions across clinical populations.

Risk factors for early revision after primary TKA in Medicare patients

BACKGROUND

Patient, surgeon, health system, and device factors are all known to influence outcomes in total knee arthroplasty (TKA). However, patient-related factors associated with an increased risk of early failure are not well understood, particularly in elderly patients.

QUESTIONS/PURPOSES

The purpose of this study was to identify specific comorbid conditions associated with increased risk of early revision in Medicare patients undergoing TKA.

METHODS

A total of 117,903 Medicare patients who underwent primary TKA between 1998 and 2010 were identified from the Medicare 5% national sample administrative database and used to determine the relative risk of revision within 12 months after primary TKA as a function of baseline medical comorbidities. Cox regression was used to evaluate the impact of 29 comorbid conditions on risk of early failure controlling for age, sex, race, census region, socioeconomic status, and all other baseline comorbidities.

RESULTS

The most significant independent risk factors for revision TKA within 12 months were chronic pulmonary disease, depression, alcohol abuse, drug abuse, renal disease, hemiplegia or paraplegia, and obesity.

CONCLUSIONS

This information could be valuable to patients and their surgeons when making shared medical decisions regarding elective TKA and for risk-stratifying publicly reported outcomes in Medicare patients undergoing TKA.

Cerebrovascular disease is associated with outcomes after total knee arthroplasty: a US total joint registry study

We assessed the association of cerebrovascular disease preoperatively with patient-reported outcomes (PROs) of moderate-severe activity limitation and moderate-severe pain at 2- and 5-years after primary total knee arthroplasty (TKA) using multivariable-adjusted logistic regression; 7139 primary and 4234 revision TKAs were included. Compared to the patients without cerebrovascular disease, those with cerebrovascular disease had a higher odds ratio (OR) of moderate-severe limitation at 2 years and 5 years, 1.32 (95% confidence interval [CI]: 1.02, 1.72; P = .04) and 1.83 (95% CI: 1.32, 2.55; P < .001), respectively. No significant associations were noted with moderate-severe pain at 2 years or 5 years. In conclusion, we found that cerebrovascular disease is independently associated with pain and function outcomes after primary TKA. This should be taken into consideration when discussing expected outcomes of TKA with patients.

Efficacy and safety of fibrin glue and tranexamic acid to prevent postoperative blood loss in total knee arthroplasty: a randomized controlled clinical trial

BACKGROUND

Postoperative blood loss in patients after total knee arthroplasty may cause local and systemic complications and influence clinical outcome. The aim of this study was to assess whether fibrin glue or tranexamic acid reduced blood loss compared with routine hemostasis in patients undergoing total knee arthroplasty.

METHODS

A randomized, single-center, parallel, open clinical trial was performed in adult patients undergoing primary total knee arthroplasty. Patients were divided into four groups. Group 1 received fibrin glue manufactured by the Blood and Tissue Bank of Catalonia, Group 2 received Tissucol (fibrinogen and thrombin), Group 3 received intravenous tranexamic acid, and Group 4 (control) had no treatment other than routine hemostasis. The primary outcome was total blood loss collected in drains after surgery. Secondary outcomes were the calculated hidden blood loss, transfusion rate, preoperative and postoperative hemoglobin, number of blood units transfused, adverse events, and mortality.

RESULTS

One hundred and seventy-two patients were included. The mean total blood loss (and standard deviation) collected in drains was 553.9 ± 321.5 mL for Group 1, 567.8 ± 299.3 mL for Group 2, 244.1 ± 223.4 mL for Group 3, and 563.5 ± 269.7 mL for Group 4. In comparison with the control group, Group 3 had significantly lower total blood loss (p < 0.001), but it was not significantly lower in Groups 1 and 2. The overall rate of patients who had a blood transfusion was 21.1% (thirty-five of 166 patients analyzed per protocol). Two patients required transfusion in Group 3 compared with twelve patients in Group 4 (p = 0.015). No significant difference was observed between the two fibrin glue groups and the control group with regard to the need for transfusion. There was no difference between groups with regard to the percentage of adverse events.

CONCLUSIONS

Neither type of fibrin glue was more effective than routine hemostasis in reducing postoperative bleeding and transfusion requirements, and we no longer use them. However, this trial supports findings from previous studies showing that intravenous tranexamic acid can decrease postoperative blood loss.

[Tranexamic acid in orthopedic surgery]

Perioperative bleeding may require blood transfusions, which are sometimes not without complications and risks, with the subsequent increase in health care costs. Among other prevention methods, treatment with tranexamic acid (ATX) has shown to be effective in reducing surgical blood loss, especially in the immediate postoperative period. In this regard, studies evaluating ATX in orthopedic surgery show that it is effective and safe when administered intravenously or intra-articularly. The usual evaluated intravenous doses range between 10mg/Kg and 20mg/kg or a fixed dose of 1g to 2g; while intra-articularly, it varies between 250 mg and 3g. ATX, as an anti-fibrinolytic has a potential thrombotic effect, thus it is contraindicated in those patients at risk or with a history of thrombosis. Its topical administration may be safer, but studies are needed to confirm this.

THE INFLUENCE OF TIBIAL PROSTHESIS DESIGN FEATURES ON STRESSES RELATED TO ASEPTIC LOOSENING AND STRESS SHIELDING

Aseptic loosening caused by mechanical factors is a recognized failure mode for tibial components of knee prostheses. This parametric study investigated the effects of prosthesis fixation design changes, which included the presence, length and diameter of a central stem, the use of fixation pegs beneath the tray, all-polyethylene versus metal-backed tray, prosthesis material stiffness, and cement mantle thickness. The cancellous bone compressive stresses and bone–cement interfacial shear stresses, plus the reduction of strain energy density in the epiphyseal cancellous bone, an indication of the likelihood of component loosening, and bone resorption secondary to stress shielding, were examined. Design features such as longer stems reduced bone and bone–cement interfacial stresses thus the risk of loosening is potentially minimized, but at the expense of an increased tendency for bone resorption. The conflicting trend suggested that bone quality and fixation stability have to be considered mutually for the optimization of prosthesis designs. By comparing the bone stresses and bone–cement shear stresses to reported fatigue strength, it was noted that fatigue of both the cancellous bone and bone–cement interface could be the driving factor for long-term aseptic loosening for metal-backed tibial trays.

Survival analysis of an asymmetric primary total knee replacement: a European multicenter prospective study

PURPOSE OF THE STUDY

This multicenter prospective study objective is to provide midterm results and 10-year survival analysis of the original Natural Knee-I System™ as experienced by a group of surgeons performing, within various settings, primary total knee replacement (TKR) in the general population.

HYPOTHESIS

The midterm experience with this TKR system in the hands of independent surgical teams can duplicate the satisfaction level that was already published by the designer's group itself.

MATERIAL AND METHOD

Two hundred and sixty-three primary TKR were performed by seven surgical teams (37 surgeons) and prospectively evaluated in four European countries. Mean age of the 263 patients (sex ratio, 2.7 females/1 male) was 69 years (range, 35-92) and diagnosis was primary osteoarthritis in 85%. For the 247 TKR with complete operative data, the approach was subvastus in 59%, posterior cruciate ligament was spared in 78%, patella was resurfaced in 56%, and 79% of reconstructions were totally cement-free. Fixation mode was only depending on the surgeon's choice.

RESULTS

At 76 months average follow-up (range 24-190 months), modified Hospital for Special Surgery knee mean score improved from 48 points preoperatively to 83 points. Four reoperations and five revision procedures were required for eight knees. Over the 14-year survey period, the overall revision rate burden was 2% and revision rate per 100 observed component/year, 0.32. At 10 years, survivorship (with revision for aseptic loosening as its end-point [two fully cementless knees]) was 98.6%.

DISCUSSION

Both this multicenter study and data drawn from national registers provided outcomes with equivalent level of satisfaction at equivalent follow-up to those reported by the NK-I prosthesis designer. There was no significant difference between revision rates of cemented, hybrid or cementless reconstructions.

CONCLUSION

In non-designer orthopaedists' hands, the Natural Knee-I System™, either with cemented or cementless fixation, provided satisfying midterm results as normally expected in primary TKR with such a modern modular prosthesis.

LEVEL OF EVIDENCE

Level IV. Prospective study.

Complications for racial and ethnic minority groups after total hip and knee replacement: a review of the literature

BACKGROUND

Total hip and knee replacement reduces disability associated with lower extremity osteoarthritis. It has been shown that racial and ethnic minority groups underutilize these procedures; however, little information exists on postoperative outcomes for ethnic minorities.

METHODS

We conducted a systematic review of the literature to compile population-based or multicenter studies on early postoperative outcomes after total hip and knee replacement in racial and ethnic minorities.

RESULTS

Nine studies met the inclusion criteria. Among the nine eligible studies, four examined total knee replacement, three examined total hip replacement, and two examined both. Two studies investigated mortality after total knee replacement, and one found that blacks had an increased risk of mortality. Three studies investigated infection after total knee replacement; all found an increased risk in blacks and Hispanics. Four studies examined non-infection-related complications after total knee replacement, and all four found that nonwhites had an increased risk of complications. Two studies investigated mortality after total hip replacement; one of these found that, for primary hip replacement, blacks had an increased risk of mortality.

CONCLUSIONS

There is a paucity of research on outcomes after orthopaedic procedures for racial and ethnic minority groups. On the basis of the available literature, racial and ethnic minority groups appear to have a higher risk for early complications (those occurring within ninety days), particularly joint infection, after total knee replacement and perhaps a higher risk of mortality after total hip replacement.

The epidemiology of revision total knee arthroplasty in the United States

Understanding the cause of failure and type of revision total knee arthroplasty (TKA) procedures performed in the United States is essential in guiding research, implant design, and clinical decision making in TKA. We assessed the causes of failure and specific types of revision TKA procedures performed in the United States using newly implemented ICD-9-CM diagnosis and procedure codes related to revision TKA data from the Nationwide Inpatient Sample (NIS) database. Clinical, demographic, and economic data were reviewed and analyzed from 60,355 revision TKA procedures performed in the United States between October 1, 2005 and December 31, 2006. The most common causes of revision TKA were infection (25.2%) and implant loosening (16.1%), and the most common type of revision TKA procedure reported was all component revision (35.2%). Revision TKA procedures were most commonly performed in large, urban, nonteaching hospitals in Medicare patients ages 65 to 74. The average length of hospital stay (LOS) for all revision TKA procedures was 5.1 days, and the average total charges were $49,360. However, average LOS, average charges, and procedure frequencies varied considerably by census region, hospital type, and procedure performed.

LEVEL OF EVIDENCE

Level II, economic and decision analysis. See Guidelines for Authors for a complete description of levels of evidence.

Patterns of functional improvement after revision knee arthroplasty

BACKGROUND

Despite the increase in the number of total knee arthroplasty revisions, outcomes of such surgery and their correlates are poorly understood. The aim of this study was to characterize patterns of functional improvement after revision total knee arthroplasty over a two-year period and to investigate factors that affect such improvement patterns.

METHODS

Three hundred and eight patients in need of revision surgery were enrolled into the study, conducted at seventeen centers, and 221 (71.8%) were followed for two years. Short Form-36 (SF-36), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Lower-Extremity Activity Scale (LEAS) scores were collected at baseline and every six months for two years postoperatively. A piecewise general linear mixed model, which models correlation between repeated measures and estimates separate slopes for different follow-up time periods, was employed to examine functional improvement patterns.

RESULTS

Separate regression slopes were estimated for the zero to twelve-month and the twelve to twenty-four-month periods. The slopes for zero to twelve months showed significant improvement in all measures in the first year. The slopes for twelve to twenty-four months showed deterioration in the scores of the WOMAC pain subscale (slope = 0.67 +/- 0.21, p < 0.01) and function subscale (slope = 1.66 +/- 0.63, p < 0.05), whereas the slopes of the other measures had plateaued. A higher number of comorbidities was consistently the strongest deterrent of functional improvement across measures. The modes of failure of the primary total knee arthroplasty were instrument-specific predictors of outcome (for example, tibial bone lysis affected only the SF-36 physical component score [coefficient = -5.46 +/- 1.91, p < 0.01], while malalignment affected both the SF-36 physical component score [coefficient = 5.41 +/- 2.35, p < 0.05] and the LEAS score [coefficient = 1.42 +/- 0.69, p < 0.05]). Factors related to the surgical technique did not predict outcomes.

CONCLUSIONS

The onset of worsening pain and knee-specific function in the second year following revision total knee arthroplasty indicates the need to closely monitor patients, irrespective of the mode of failure of the primary procedure or the surgical technique for the revision. This information may be especially important for patients with multiple comorbidities.

Does concomitant low back pain affect revision total knee arthroplasty outcomes?

The number of revision total knee arthroplasties (rev-TKA) is increasing every year. These cases are technically difficult and add considerable burden on the healthcare system. Many patients have concomitant low back pain that may interfere with functional outcome. We asked whether having low back pain at baseline would influence amount and rate of improvement on standardized outcomes measures after rev-TKA. We retrospectively reviewed 308 patients from prospectively collected data in a multicenter study. A minimum 24-month followup was available for 221 patients (71.8%). Patients with low back pain at baseline had worse scores on most instruments than their counterparts at baseline, 12 months postsurgery, and 24 months postsurgery. The data suggest concomitant back pain in patients undergoing rev-TKA affects their outcomes as measured by standardized instruments. Orthopaedic surgeons should counsel their patients with back pain regarding the possibility of slower or less complete recovery.

LEVEL OF EVIDENCE

Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Analysis of the outcome in male and female patients using a unisex total knee replacement system

Gender-specific total knee replacement has generated much interest recently. We reviewed 1970 Sigma knees implanted in 920 women and 592 men with a mean age of 69.7 years. At a mean follow-up of 7.3 years (minimum, five years), we found minimal differences in the outcome between genders. At the final follow-up, men had a higher overall Knee Society score and more osteolysis (3.8% vs 1.1%). However, there were no significant differences between men and women in terms of complications or improvements in knee function, pain score or range of movement. The estimated ten-year survivorship was 97% in women and 98% in men (p = 0.96). We concluded that there was little difference in outcome between the genders treated by a modern unisex design of total knee replacement in this large multicentre study.

The effect of an augmentation patella prosthesis versus patelloplasty on revision patellar kinematics and quadriceps tendon force: an ex vivo study

The purpose of this study was to assess the effect of 2 revision reconstructive interventions on patellofemoral joint mechanics in comparison to control. We flexed 8 cadaver knee specimens from 0 degrees to 60 degrees of flexion in a test rig designed to simulate weight-bearing flexion and extension (Oxford rig). Quadriceps tendon extensor force and patellar kinematics were recorded for control total knee arthroplasty (TKA) (normal primary TKA with patella resurfaced) and then for each of the 2 revision patellar interventions (after patelloplasty of typical revision knee patellar bone defect to leave a simple bony shell, and after TKA with augmentation patella resurfacing). Our results demonstrate that patellar kinematics and quadriceps extensor force are optimized when the patella is reconstructed to normal anteroposterior thickness.

Tibial tubercle osteotomy in primary total knee arthroplasty: a safe procedure or not?

The objective of this study was to investigate the influence of tibial tubercle osteotomy on postoperative outcome, intra- and postoperative complications, as well as postoperative clinical results and failures in primary total knee arthroplasty (TKA). In a continuous, consecutive series of 1474 primary TKA, we analysed 126 cases where a tibial tubercle osteotomy approach was performed and 1348 cases without tibial tubercle osteotomy. Before surgery, all patients underwent a systematic assessment that included a clinical examination, radiographs (stress hip-knee-ankle film [pangonogram], weight bearing, anteroposterior knee view, schuss view, profile and patellar axial view at 30 degrees, stress valgus and varus view) and International Knee Society scores. When analysing intraoperative complications, tibial plateau fissures or fractures and tibial tubercle fracture were considered as complications relating to the tibial tubercle osteotomy group (p<0.001, p=0.007). With a 2-year minimum follow-up, there was no statistical difference in the number of revisions carried out in the two study groups (p=0.084). However, postoperative tibial tubercle fracture and skin necrosis were significantly related to the osteotomy (p=0.001 and p</=0.001, respectively). Tibial tubercle osteotomy cannot be considered an entirely safe procedure in primary TKA as it is associated with local complications, particularly skin necrosis and fracture of the tibial tubercle. Therefore, tibial tubercle osteotomy should be performed only when necessary, i.e. in cases where there are difficulties gaining adequate surgical exposure, ligament balance and correct implant positioning. The procedure also demands considerable surgical experience to achieve a good outcome.

What patient and surgical factors contribute to implant wear and osteolysis in total joint arthroplasty?

Total joint arthroplasty has been a successful operation for decades. Our current patients are younger and more active than those in the past. They place higher demands on themselves and have expectations commensurate with their lifestyles. Time-limited longevity with the large number of anticipated total joint replacement procedures and their potential burden to health care is a growing concern. In the past two decades, implant wear and osteolysis have been identified as major causes for the failure of otherwise well-functioning implants. Osteolysis can be divided into several categories: patient-specific, implant-specific, and the result of surgical factors. Although these categories are interrelated and not mutually exclusive, they enable us to build a framework in which to further advance our understanding of osteolysis and apply this information in a clinically relevant manner.

Selfprotective smart orthopedic implants

In this review, we discuss current advances leading to an exciting change in implant design for orthopedic surgery. The initial biomaterial approaches in implant design are being replaced by cellular-molecular interactions and nanoscale chemistry. New designs address implant complications, particularly loosening and infection. For infection, local delivery systems are an important first step in the process. Selfprotective 'smart' devices are an example of the next generation of orthopedic implants. If proven to be effective, antibiotics or other active molecules that are tethered to the implant surface through a permanent covalent bond and tethering of antibiotics or other biofactors are likely to transform the practice of orthopedic surgery and other medical specialties. This new technology has the potential to eliminate periprosthetic infection, a major and growing problem in orthopedic practice.