Revision total hip replacement: predictors of blood loss, transfusion requirements, and length of hospitalisation

Conversion of hip resurfacing to total hip arthroplasty: is the outcome closer to primary or revision total hip arthroplasty?

BACKGROUND

Along with the advent of newer bearings, hip resurfacing (HR) is gaining renewed interest as a bone sparing alternative to conventional total hip arthroplasty (THA) in young patients. However, the outcome of conversion of failed HR to THA (HRc) remains sparsely described. This study aimed to compare the outcomes and complication rates of HRc to those of primary (pTHA) and revision THA (rTHA) to find out to which group HRc is most comparable.

HYPOTHESIS

The study hypothesis was that the outcomes and complications rates of HRc were closer to those of pTHA than rTHA.

MATERIALS AND METHODS

Between 2001 and 2011, a continuous series of 207 HR were prospectively included in our institutional registry and retrospectively analyzed. Out of them, 17 HR (8%) were converted to THA. Propensity scores were used to match patients in the HRc group to the pTHA and the rTHA groups using a greedy 1:3 matching procedure (51 pTHA and 51 rTHA). Clinical and radiographic outcomes, perioperative data and complications were analyzed and compared between the three groups.

RESULTS

No significant difference between HRc and pTHA was observed in terms of clinical and functional outcomes, duration of surgery, acetabular component diameter and length of hospital stay (p = 0.13 to 0.94). Perioperative blood loss was significantly lower for pTHA than for HRc (p = 0.01). HRc demonstrated significantly higher HHS and HOOS scores than for rTHA at one year (p = 0.03 and p < 0.01, respectively). Duration of surgery was significantly lower in HRc compared to rTHA (p = 0.02) while length of hospital stay was similar (p = 0.84). Complication rate was significantly higher in the rTHA group, compared to HRc and pTHA groups (37.3 vs. 29.4 vs. 11.8%, p = 0.01).

CONCLUSION

This study demonstrated that the clinical and functional outcomes of HRc were closer to those of pTHA than those of rTHA, though complication rate was higher than for pTHA.

LEVEL OF EVIDENCE

III; Retrospective comparative study.

Suction drain usage has no benefit following revision total hip and knee arthroplasty

INTRODUCTION

The use of drains after primary total joint arthroplasty (TJA) has shown little benefit. Few studies have investigated drain usage after revision TJA. The purpose of this study was to determine whether utilizing suction drains is beneficial for patients undergoing revision arthroplasty.

MATERIALS AND METHODS

We performed a comprehensive literature review utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines from the PubMed, Embase, Web of Science, and Cochrane Library. Inclusion criteria of this review were all original articles written in English investigating the efficacy and safety of closed suction drainage in revision TKA or THA, reporting at least one of the following outcome measures: (1) estimated blood loss (EBL), (2) perioperative hemoglobin change, (3) needs for transfusion, (4) postoperative infection, and (5) wound complications. Articles were excluded if they are not available in English or they included case reports, systematic reviews, comments, editorials, surveys, or animal studies prior to July 22, 2023. A total of six studies met inclusion criteria. In total, 655 patients had a drain while 1765 patients did not have a drain after revision total hip or knee arthroplasty. Primary outcomes included for meta-analysis included estimated blood loss (EBL), postoperative hemoglobin, need for transfusion. Other data extracted includes postoperative infections, and wound complications.

RESULTS

Six studies met the inclusion criteria. In total, 655 patients had drains, while 1765 patients did not after revision total hip or knee arthroplasty. The average age of the patients was 66.1+/- 3.4 years, and the average BMI was 30.3 +/-0.8. There was no difference in postoperative infections (p = 0.14), wound complications (p = 0.621) or need for transfusion (p = 0.521) between the two groups. There was also no difference in EBL (Hedges' g CI[-3.52, 2.77]) or postoperative Hb (Hedges' g CI[-1.65, 2.41]) between patients with and without drains.

CONCLUSIONS

Our results do not show any benefit from drain placement after revision total hip or knee arthroplasty. With the increased cost, time and need for drain removal, this is likely an unnecessary intervention.

LEVEL OF EVIDENCE

Level III, systematic review and meta-analysis.

Risk factors for complications in total hip arthroplasty

INTRODUCTION AND OBJECTIVE

Hip arthroplasty represents a significant advancement in the treatment of refractory chronic joint pain, improving quality of life and functionality. The objective of this study is to identify the risk factors associated with local and systemic complications in patients treated with total hip arthroplasty.

METHODS

Observational, analytical, retrospective cohort study, which included 304 participants treated with total hip replacement. Comparison of variables between two groups was performed; 38 participants in the group with complications and 266 participants in the group without complications.

RESULTS

The mean age in the complication group was 66 years (SD 18.7) and in the uncomplicated group it was 67,1 years (SD 15.1) (p 0,686). Female sex was observed in 73.3% of the group with complications and 65% in the group without complications. (p 0.292). Risk factors were: hip fracture as an indication for arthroplasty RR 1.33 [95% CI 1.004;1.775 p 0.047], coronary heart disease RR 1.31 [95% CI 1.067;1.616 p 0.010] and surgical bleeding equal to or greater than 400 cc RR 1.11 [95% CI 1.012;1.218 p 0.028].

CONCLUSIONS

The risk factors for complications in total hip arthroplasty were: hip fracture as the indication for arthroplasty, coronary artery disease, and surgical bleeding equal to or greater than 400 cc.

Allogeneic Blood Transfusion and Risk of Postoperative Complications in Patients with Mild and Moderate Anemia of Any Cause? A Retrospective Cohort Study in Total Revision Hip Surgery

Introduction

Patients undergoing revision total hip surgery (RTHS) have a high prevalence of mild and moderate preoperative anemia, associated with adverse outcomes. The aim of this study was to investigate the association of perioperative allogeneic blood transfusions (ABT) and postoperative complications in preoperatively mild compared to moderate anemic patients undergoing RTHS who did not receive a diagnostic anemia workup and treatment before surgery.

Methods

We included 1,765 patients between 2007 and 2019 at a university hospital. Patients were categorized according to their severity of anemia using the WHO criteria of mild, moderate, and severe anemia in the first Hb level of the case. Patients were grouped as having received no ABT, 1-2 units of ABT, or more than 2 units of ABT. Need for intraoperative ABT was assessed in accordance with institutional standards. Primary endpoint was the compound incidence of postoperative complications. Secondary outcomes included major/minor complications and length of hospital and ICU stay.

Results

Of the 1,765 patients, 31.0% were anemic of any cause before surgery. Transfusion rates were 81% in anemic patients and 41.2% in nonanemic patients. The adjusted risks for compound postoperative complication were significantly higher in patients with moderate anemia (OR 4.88, 95% CI: 1.54-13.15, p = 0.003) but not for patients with mild anemia (OR 1.93, 95% CI: 0.85-3.94, p < 0.090). Perioperative ABT was associated with significantly higher risks for complications in nonanemic patients and showed an increased risk for complications in all anemic patients. In RTHS, perioperative ABT as a treatment for moderate preoperative anemia of any cause was associated with a negative compound effect on postoperative complications, compared to anemia or ABT alone.

Discussion

ABT is associated with adverse outcomes of patients with moderate preoperative anemia before RTHS. For this reason, medical treatment of moderate preoperative anemia may be considered.

Ambulatory status after revision total hip arthroplasty in elective versus fracture indications

INTRODUCTION

To improve revision total hip arthroplasty (rTHA) prognosis and postoperative management, a better understanding of how non-elective and elective indications influence clinical outcomes is needed. We sought to compare ambulatory status, complication rates, and implant survival rates in patients who underwent aseptic rTHA for periprosthetic fracture or elective indications.

MATERIALS AND METHODS

This retrospective study examined all aseptic rTHA patients with a minimum follow-up of two years at a single tertiary referral center. Patients were divided into two groups: fracture rTHA (F-rTHA) if the patient had a periprosthetic femoral or acetabular fracture, and elective rTHA (E-rTHA) if the patient underwent rTHA for other aseptic indications. Multivariate regression was performed for clinical outcomes to adjust for baseline characteristics, and Kaplan-Meier analysis was performed to assess implant survival.

RESULTS

A total of 324 patients (F-rTHA: 67, E-rTHA: 257) were included. In the F-rTHA cohort, 57 (85.0%) and 10 (15.0%) had femoral and acetabular periprosthetic fractures, respectively. F-rTHA patients were more likely to be discharged to skilled nursing (40.3% vs. 22.2%, p = 0.049) and acute rehabilitation facilities (19.4% vs. 7.8%, p = 0.004). F-rTHA patients had higher 90-day readmission rates (26.9% vs. 16.0%, p = 0.033). Ambulatory status at three months postoperatively significantly differed (p = 0.004); F-rTHA patients were more likely to use a walker (44.6% vs. 18.8%) and less likely to ambulate independently (19.6% vs. 28.6%) or with a cane (28.6% vs. 41.1%). These differences did not persist at one and two years postoperatively. Freedom from all-cause re-revision (77.6% vs. 74.7%, p = 0.912) and re-revision due to PJI (88.1% vs. 91.9%, p = 0.206) were similar at five-year follow-up.

CONCLUSIONS

Compared to rTHA performed for elective aseptic indications, fracture rTHA patients had poorer early functional outcomes, with greater need for ambulatory aids and non-home discharge. However, these differences did not persist long term and did not portend increased infection or re-revision rates.

Predictive Factors for Length of Stay in Patients Undergoing Total Hip Arthroplasty: A Cross-Sectional Study

Background

Total hip arthroplasty (THA) is an effective surgery for patients with end-stage hip joint degenerative arthritis. This study aimed to determine peri-operative factors that impact the length of stay (LOS) and design a formula to predict LOS in patients undergoing THA.

Methods

This cross-sectional study was performed from September 2019 to January 2020. For this study, all patients who underwent THA over a period of 12 years since 2005 were included in the study. Data about the LOS and several variables including demographic variables, surgery-related variables, transfusion, intensive care unit (ICU) admission, past drug history, comorbidities, and laboratory data, were gathered. Qualitative variables are presented as numbers (%), and quantitative variables are presented as mean Mann± standard deviation. Mann Whitney test , Kruskal-Wallis test, and Spearman's rank correlation test were also used.

Results

A total of 524 patients were included in the study; 12 were excluded .261 (51%) were female and 251(49%) male. The mean age was 56.13±17.04 years. In the univariate analysis, the day of admission, surgery indication, transfusion, diabetes mellitus, oral anti-diabetic drugs, American Society of Anesthesiology (ASA) score, preoperative hemoglobin (Hb) level, and type of prosthesis showed significant relation with LOS. Significant variables entered to zero truncated negative binomial regression. Among them, the day of admission, ASA score, preoperative Hb level, and type of prosthesis showed significant relation with LOS (P < 0.05) and were used for model design.

Conclusion

Preoperative Hb level, ASA score, day of admission, and prosthesis type have an impact on LOS and can predict LOS in patients who are candidates for THA.

Validation of Machine Learning Model Performance in Predicting Blood Transfusion After Primary and Revision Total Hip Arthroplasty

BACKGROUND

The rates of blood transfusion following primary and revision total hip arthroplasty (THA) remain as high as 9% and 18%, respectively, contributing to patient morbidity and healthcare costs. Existing predictive tools are limited to specific populations, thereby diminishing their clinical applicability. This study aimed to externally validate our previous institutionally developed machine learning (ML) algorithms to predict the risk of postoperative blood transfusion following primary and revision THA using national inpatient data.

METHODS

Five ML algorithms were trained and validated using data from 101,266 primary THA and 8,594 revision THA patients from a large national database to predict postoperative transfusion risk after primary and revision THA. Models were assessed and compared based on discrimination, calibration, and decision curve analysis.

RESULTS

The most important predictors of transfusion following primary and revision THA were preoperative hematocrit (<39.4%) and operation time (>157 minutes), respectively. All ML models demonstrated excellent discrimination (area under the curve (AUC) >0.8) in primary and revision THA patients, with artificial neural network (AUC = 0.84, slope = 1.11, intercept = -0.04, Brier score = 0.04), and elastic-net-penalized logistic regression (AUC = 0.85, slope = 1.08, intercept = -0.01, and Brier score = 0.12) performing best, respectively. On decision curve analysis, all 5 models demonstrated a higher net benefit than the conventional strategy of intervening for all or no patients in both patient cohorts.

CONCLUSIONS

This study successfully validated our previous institutionally developed ML algorithms for the prediction of blood transfusion following primary and revision THA. Our findings highlight the potential generalizability of predictive ML tools developed using nationally representative data in THA patients.

Intraoperative cell salvage in revision hip arthroplasty

Aims

The aim of this study was to perform a systematic review of the evidence for the use of intraoperative cell salvage in patients undergoing revision hip arthroplasty, and specifically to analyze the available data in order to quantify any associated reduction in the use of allogenic blood transfusion, and the volume which is used.

Methods

An electronic search of MEDLINE (PubMed), Embase, Scopus, and the Cochrane Library was completed from the date of their inception to 24 February 2022, using a search strategy and protocol created in conjunction with the PRISMA statement. Inclusion criteria were patients aged > 18 years who underwent revision hip arthroplasty when cell salvage was used. Studies in which pre-donated red blood cells were used were excluded. A meta-analysis was also performed using a random effects model with significance set at p = 0.05.

Results

Of the 283 studies which were identified, 11 were included in the systematic review, and nine in the meta-analysis. There was a significant difference (p < 0.001) in the proportion of patients requiring allogenic transfusion between groups, with an odds ratio of 0.331 (95% confidence interval (CI) 0.165 to 0.663) associated with the use of cell salvage. For a total of 561 patients undergoing revision hip arthroplasty who were treated with cell salvage, 247 (44.0%) required allogenic transfusion compared with 418 of 643 patients (65.0%) who were treated without cell salvage. For those treated with cell salvage, the mean volume of allogenic blood which was required was 1.95 units (390 ml) per patient (0.7 to 4.5 units), compared with 3.25 units (650 ml) per patient (1.2 to 7.0 units) in those treated without cell salvage. The mean difference of -1.91 units (95% CI -4.0 to 0.2) in the meta-analysis was also significant (p = 0.003).

Conclusion

We found a a significant reduction in the need for allogenic blood transfusion when cell salvage was used in patients undergoing revision hip arthroplasty, supporting its routine use in these patients. Further research is required to determine whether this effect is associated with types of revision arthroplasty of differing complexity.

Revision Hip Arthroplasty in a Jehovah's Witness with Pelvic Discontinuity: A Case Report

CASE

A 68-year-old Jehovah's Witness (JW) presented with pelvic discontinuity 9 years after right total hip arthroplasty. Her pelvis was previously irradiated for cervical cancer. Meticulous hemostasis, blood conserving strategies, and a prophylactic arterial balloon catheter were used to mitigate bleeding. She underwent an uneventful revision total hip arthroplasty with excellent functional recovery and radiographic evaluation at 1 year postoperatively.

CONCLUSION

Pelvic discontinuity in a JW with irradiated bone makes for a challenging revision arthroplasty with high bleeding risk. Preoperative coordination with anesthesia and blood loss mitigation strategies can lead to successful surgical outcomes in cases of high-risk surgery among JW patients.

Optimising the use of cell salvage in revision hip arthroplasty

BACKGROUND

Intraoperative cell salvage is an established method to reduce the requirement for and the volume of allogenic blood transfusion but adds to the financial cost of performing surgery.

AIMS

The primary aim of this study was to determine which patients and what type of revision hip surgery benefit most from intraoperative cell salvage.

METHODS

This observational study included patients who underwent revision hip surgery performed by the senior author at a single orthopaedic unit. The cohort was divided into single and two-component revision groups; then, the transfusion requirement combined with analysis of patient factors was used to create a decision-making protocol.

FINDINGS

The two-component group had a significantly higher number of cases using cell salvage and a higher total transfusion volume. Patients who required postoperative allogenic blood transfusions had a higher mean age, were less likely to have received tranexamic acid and had a lower preoperative haemoglobin level.

CONCLUSION

Based on these results, a decision-making protocol was developed for when to use cell salvage in revision hip surgery.

Single Position Lateral Lumbar Interbody Fusion With Posterior Instrumentation Utilizing Computer Navigation and Robotic Assistance: Retrospective case review and surgical technique considerations

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine safety and short-term outcomes of single-position lateral lumbar interbody fusion (LLIF) with bilateral posterior instrumentation and robotic assistance. The article also describes surgical technique considerations for the procedure.

METHODS

20 patients underwent single-position LLIF with posterior instrumentation and robotic assistance. The patients were followed for a minimum of 3 months post-operatively.

RESULTS

Average operative time was 211 ± 34 minutes, average blood loss was 51.25 ± 17 cc's, and average length of stay was 1.4 ± .75 days. There were no intraoperative complications, readmissions, revision surgeries, and no incidence of hardware malposition. Significant improvement in pain and ODI scores was noted at 3 month follow up.

CONCLUSIONS

The study demonstrated safety and short-term clinical efficacy of minimally invasive single-position lateral lumbar interbody fusion with bilateral posterior instrumentation utilizing robotic assistance and navigation. There are certain surgical technique considerations that must be followed to ensure optimal surgical workflow and predictable outcomes.

How Does Iron Deficiency Anemia Impact Outcomes following Revision Total Hip Arthroplasty?

Purpose

Studies have shown the prevalence of iron deficiency anemia (IDA) increasing worldwide, and currently the literature is limited on the impact of IDA on outcomes following revision total hip arthroplasty (RTHA). Therefore, the purpose of this study was to determine whether IDA patients undergoing RTHA have longer: 1) in-hospital lengths of stay (LOS); 2) medical complications; and 3) costs of care.

Materials and Methods

A retrospective query of a nationwide administrative claims database was performed. Using Boolean command operations, the study group consisted of all patients in the database undergoing RTHA with IDA; whereas, patients without IDA served as controls. To reduce the effects of confounding, study group patients were matched to controls in a 1:5 ratio by age, sex, and medical comorbidities yielding 92,948 patients with (n=15,508) and without (n=77,440) IDA undergoing revision THA. A P-value less than 0.001 was considered statistically significant.

Results

IDA patients were found to have significantly longer in-hospital LOS (5 days vs. 4 days, P<0.0001). Additionally, the study showed IDA patients were found to higher incidence and odds of (73.84% vs. 11.77%, OR 5.04, P<0.0001) 90-day medical complications. IDA patients also incurred high 90-day episode of care costs ($25,597.51 vs. $20,085.70, P<0.0001).

Conclusion

After adjusting for age, sex, and medical comorbidities this study of over 92,000 patients demonstrated IDA is associated with longer in-hospital LOS, complications, and costs of care. Future studies should compare the duration and severity of IDA on outcomes.

Tranexamic acid lowers transfusion requirements and hospital length of stay following revision total hip or knee arthroplasty

Backgroud

Intravenous tranexamic acid (TXA) has been shown to reduce blood loss in patients undergoing total joint arthroplasty without systemic complications. There is limited evidence of its effectiveness in revision procedures. This study evaluated intravenous TXA effect on blood loss, transfusion rates, and length of hospital stay in revision joint replacement.

Methods

One-hundred revision total joint arthroplasty patients were retrospectively reviewed [44 revision total hip arthroplasty (THA) and 54 revision total knee arthroplasty (TKA)] who underwent surgery from 2013 to 2016. Fifty-four revision joint patients (23 THA and 31 TKA) received intravenous TXA intra-operatively, while 46 revision joint patients (23 THA/TKA) did not. Primary outcome measures were blood loss, transfusion rates, and length of hospital stay.

Results

The mean blood loss difference between revision THA patients who received TXA vs. not receiving TXA was 180ml in revision THA patients (p < .005). Mean length of hospital stay was 6 days in non-TXA vs. 3 days in TXA patients (p < .001). Eighteen patients received transfusions in the non-TXA revision TKA group compared to nine patients in the TXA revision TKA group (p < .001). Average length of hospital stay was 5 days in the non-TXA revision TKA group compared to 3 days in the TXA revision TKA group (p < .003). There was no increased risk of thromboembolic complications in TXA groups for either procedure.

Conclusions

Intravenous TXA reduced length of hospital stay in both revision cohorts, decreased blood loss in revision THA and decreased the rate of transfusion in revision TKA without an increase in thromboembolic complications.

Level of Evidence

Level III (Case-control study)

Single position circumferential fusion improves operative efficiency, reduces complications and length of stay compared with traditional circumferential fusion

BACKGROUND CONTEXT

Anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) with percutaneous posterior screw fixation are two techniques used to address degenerative lumbar pathologies. Traditionally, these anterior-posterior (AP) surgeries involve repositioning the patient from the supine or lateral decubitus position to prone for posterior fixation. To reduce operative time (OpTime) and subsequent complications of prolonged anesthesia, single-position lumbar surgery (SPLS) is a novel, minimally invasive alternative performed entirely from the lateral decubitus position.

PURPOSE

Assess the perioperative safety and efficacy of single position AP lumbar fusion surgery (SPLS).

STUDY DESIGN

Multicenter retrospective cohort study.

PATIENT SAMPLE

Three hundred and ninety patients undergoing AP surgery were included, of which 237 underwent SPLS and 153 were in the Flip group.

OUTCOME MEASURES

Outcome measures included levels fused, percentage of cases including L5-S1 fusion, fluoroscopy radiation dosage, OpTime, estimated blood loss (EBL), length of stay (LOS), and perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence, pelvic tilt, and segmental LL.

METHODS

Patients undergoing primary ALIF and/or LLIF surgery with bilateral percutaneous pedicle screw fixation between L2-S1 were included over a 4-year period. Patients were classified as either traditional repositioned "Flip" surgery or SPLS. Outcome measures included levels fused, percentage of cases including L5-S1 fusion, fluoroscopy radiation dosage, OpTime, EBL, LOS, perioperative complications. Radiographic analysis included LL, pelvic incidence, pelvic tilt, and segmental LL. All measures were compared using independent samples t-tests and chi-squared analyses as appropriate with significance set at p < .05. Propensity matching was completed where demographic differences were found.

RESULTS

Three hundred and ninety patients undergoing AP surgery were included, of which 237 underwent SPLS and 153 were in the Flip group. Age, gender, BMI, and CCI were similar between groups. Levels fused (1.47 SPLS vs 1.52 Flip, p = .468) and percent cases including L5-S1 (31% SPLS, 35% Flip, p = .405) were similar between cohorts. SPLS significantly reduced OpTime (103 min vs 306 min, p < .001), EBL (97 vs 313 mL, p < .001), LOS (1.71 vs 4.12 days, p < .001), and fluoroscopy radiation dosage (32 vs 88 mGy, p < .001) compared to Flip. Perioperative complications were similar between cohorts with the exception of postoperative ileus, which was significantly lower in the SPLS group (0% vs 5%, p < .001). There was no significant difference in wound, vascular injury, neurological complications, or Venous Thrombotic Event. There was no significant difference found in 90-day return to operating room (OR).

CONCLUSIONS

SPLS improves operative efficiency in addition to reducing blood loss, LOS and ileus in this large cohort study, while maintaining safety.

Factors Associated With Perioperative Transfusion in Lower Extremity Revision Arthroplasty Under a Restrictive Blood Management Protocol

INTRODUCTION

Approximately 37% of patients undergoing lower extremity revision total joint arthroplasty (TJA) receive allogeneic blood transfusions (ABTs), which are associated with increased risk of morbidity and death. It is important to identify patient factors associated with needing ABT because the health of higher-risk patients can be optimized preoperatively and their need for ABT can be minimized. Our goal was to identify the patient and surgical factors independently associated with perioperative ABT in revision TJA.

METHODS

We included all 251 lower extremity revision TJA cases performed at our academic tertiary care center from January 1, 2016, to December 31, 2018. We assessed the following factors for associations with perioperative ABT: patient age, sex, race, body mass index, preoperative hemoglobin level, and infection status (ie, infection as indication for revision TJA); use of vasopressors, tranexamic acid (TXA), surgical drains, tourniquets, and intraoperative cell salvage; and procedure type (hip versus knee), procedure complexity (according to the number of components revised), and surgical time. Multivariable regression was used to identify factors independently associated with perioperative ABT.

RESULTS

The following characteristics were independently associated with greater odds of perioperative ABT: preoperative hemoglobin level (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.5 to 2.2), infectious indication for revision (OR, 3.6; 95% CI, 1.3 to 9.7), and procedure complexity. TXA use was a negative predictor of ABT (OR, 0.47; 95% CI, 0.23 to 0.98). Compared with polyethylene liner exchanges, single-component revisions (OR, 14; 95% CI, 3.6 to 56) and dual-component revisions (OR, 7.8; 95% CI, 2.3 to 26) were associated with greater odds of ABT.

DISCUSSION

Patients with preoperative anemia, those undergoing revision TJA because of infection, those who did not receive TXA, and those undergoing more complex TJA procedures may have greater odds of requiring ABT. We recommend preoperative optimization of the health of these patients to reduce the need for ABT.

LEVEL OF EVIDENCE

Level III, prognostic study.

Intravenous tranexamic acid for reducing perioperative blood loss during revision hip arthroplasty: A retrospective study

OBJECTIVE

This study aimed to explore the efficacy and safety of intravenous tranexamic acid (TXA) for reducing perioperative blood loss and allogeneic blood transfusions in revision hip arthroplasty.

METHODS

TXA was routinely administered as an intravenous preoperative dose in all the revision hip arthroplasty cases in our institution from December 2012. We retrospectively reviewed 803 patients who underwent revision hip arthroplasty from January 2008 to September 2018. These patients were divided into 2 groups based on whether they received intravenous TXA (n=482; 231 men and 251 women; mean age: 63.27±11.73 years) or not (n=321; 159 men and 162 women; mean age: 63.91±11.69 years). The 2 groups were compared in terms of estimated intraoperative blood loss, visible blood loss, hidden blood loss, the rate and volume of allogeneic blood transfusions, and the incidence of symptomatic venous thromboembolism. The patients were also compared depending on whether they underwent total hip revision, isolated acetabular revision, or isolated femoral revision.

RESULTS

Regardless of the type of revision involved, the patients who received TXA showed significantly lower estimated intraoperative blood loss, visible blood loss, hidden blood loss, and allogeneic blood transfusion rate and volume (all p values were less than 0.001). Use of TXA was not associated with significant changes in the incidence of postoperative symptomatic venous thromboembolism (p=0.911). Similar results were obtained with subgroups of patients who underwent different types of revision surgeries, except hidden blood loss (p=0.994) of patients in the isolated femoral revision subgroup.

CONCLUSION

The administration of intravenous TXA can safely and effectively reduce the perioperative blood loss and allogeneic blood transfusions in revision hip arthroplasty.

LEVEL OF EVIDENCE

Level III, Therapeutic study.

Increased risk of complications in patients with hypoalbuminemia undergoing revision total hip arthroplasty

Objective

The relationship between hypoalbuminemia and complications after revision total hip arthroplasty (THA) has not been established. We hypothesize that hypoalbuminemia is associated with complications in patients undergoing revision THA.

Methods

The ACS-NSQIP database was queried for patients undergoing revision THA. Chi square and regression analyses were used to assess the relationship between hypoalbuminemia, demographics, other comorbidities, and complications.

Results

Hypoalbuminemia is associated with an increased risk of reoperation, bleeding complications, surgical site infections, non-routine discharge, medical complications, and surgical complications.

Conclusions

Albumin levels should be considered in the preoperative planning of patients undergoing revision THA for possible nutritional optimization.

Diagnosis of depression and other patient factors impacts length of stay after total knee arthroplasty

Background

The length of in-hospital stay (LOS) is an important measure of efficiency in the use of hospital resources and care quality outcomes after orthopaedic surgery. This study investigated the influence of patients' characteristics including demographic factors and the presence of comorbid preoperative depression on LOS after primary total knee arthroplasty (TKA).

Methods

Data were extracted from the California Healthcare Cost and Utilization Project database for hospital discharges after primary TKA for adults aged 50 years and older from 2007 to 2010 (n = 133,603). LOS was defined as the difference in days between the date of admission and the date of discharge. We included demographic data (age, sex, race), comorbidity of depression, and years of admission as covariates in the multivariable model. Negative binomial regression was used to model the effect(s) of covariates on the LOS. As a secondary analysis, the association of covariates with the extended LOS (>9 days) was also investigated using logistic regression.

Results

Our study showed that female sex, age, Medicaid insurance, and race were associated with a longer LOS. Most importantly, a diagnosis of depression was associated with a significantly longer LOS (1.05 times longer: 95% CI: 1.04-1.06) and was independently associated with 1.83 times higher odds (95% CI: 1.50-2.23) of belonging to the extended LOS group. Compared to 2007, significant reductions of both LOS and a longer LOS were noted throughout all later years from 2008 to 2010.

Conclusions

Our study revealed that a diagnosis of depression and patient's characteristic such as age, female sex, Medicaid, nonwhite race resulted in a statistically significant increased LOS. These findings can be useful for planning and resource allocation for total knee replacement programs.

Thromboprophylaxis for Hip Revision Arthroplasty: Can We Use the Recommendations for Primary Hip Surgery? A Cohort Study

The risk of thromboembolic events after hip revision arthroplasty might be higher than in primary hip arthroplasty. However, evidence regarding the use of thromboprophylaxis in revisions is scarce. The purpose of this study is to determine whether thromboprophylaxis recommendations for primary arthroplasty produce similar results in hip revision arthroplasty. This comparative cohort study retrospectively analyzed consecutive patients undergoing primary hip arthroplasty and hip revision surgery between March 2004 and December 2015, who received thromboprophylaxis according to local clinical practice guidelines for primary hip arthroplasty. The prevalence of deep vein thrombosis and pulmonary embolism and the presence of major bleeding events were assessed during hospitalization and at 3 months after discharge and compared between groups. The overall prevalence of thromboembolic events in the hip revision surgery cohort and in the primary hip cohort was 1.62% and 1.35%, respectively (P = .801). The 38.4% of hip revision patients and 20.3% of primary hip patients presented major bleeding events. Thromboembolic disease outcomes with the use of a standardized thromboprophylaxis regimen were similar in both cohorts, regardless of the high variability of hip revision surgery and the increased risk of complications. Implementation of this regimen is recommended in patients requiring joint replacement revision surgery.

Intraoperative hemorrhage in revision total hip arthroplasty: a retrospective single-center study

PURPOSE

The amount of intraoperative hemorrhages and factors associated with hemorrhages and transfusions during revision total hip arthroplasty (reTHA) have not been identified for Japanese patients. We aimed to clarify the amount of intraoperative hemorrhages, and to elucidate the factors associated with hemorrhages and transfusions during reTHA in Japanese patients.

METHODS

We retrospectively reviewed patients who underwent reTHA (n = 48) and primary total hip arthroplasty (pTHA) (n = 615) in a single hospital and extracted data regarding hemorrhage, transfusion, patient comorbidities, and surgical anesthesia. We defined massive blood loss (MBL) as a hemorrhage comprising more than half of the circulating blood volume within 3 h. The odds ratio (OR) and 95% confidence interval (CI) were estimated using a multivariate logistic regression analysis.

RESULTS

There was a significant difference in hemorrhages between reTHA and pTHA patients (1790 g versus 625 g; p < 0.001). Among patients with reTHA, MBL was significantly associated with younger age (OR 0.91; 95% CI 0.84-1.00; p = 0.04) and lower body mass index (BMI) (OR 0.69; 95% CI 0.53-0.91; p = 0.01). Although not significant, the incidence of MBL tended to be higher for patients with hyperlipidemia (OR 4.88; 95% CI 0.99-24.1; p = 0.051). Furthermore, the need for allogeneic transfusion was significantly associated with the number of prepared autologous blood packs (OR 0.15; 95% CI 0.07-0.55; p = 0.002).

CONCLUSION

Although this study was limited by its small population and a possibility of underestimating the hemorrhage, hemorrhages in reTHA patients was two times greater than that in pTHA patients. Younger age and lower BMI increased the risk of MBL in reTHA. Preparing autologous blood decreased the risk of intraoperative allogeneic transfusion.

FIBTEM as a predictor of intra- and postoperative blood loss in revision total hip arthroplasty: A prospective observational study

Revision total hip arthroplasty (THA) may cause intra- and postoperative massive bleeding. This prospective observational study evaluated if the maximum clot firmness of FIBTEM (MCFFIB) could act as a predictor of perioperative massive bleeding in revision THA.Fifty-eight adult patients undergoing revision THA were included. Pre- and postoperative MCFFIB, hematological and hemostatic laboratory data, as well as the amount of intra- and postoperative blood loss (IBL and PBL) were obtained.The change rate (MCFFIB-C) between the pre- and postoperative MCFFIB had a significant correlation with IBL (ρ = 0.431, P = .001). Moreover, PBL had a significant correlation with MCFFIB-C (ρ = 0.292, P = .026). The MCFFIB-C cut-off value of ≥ 29% showed the highest sensitivity and specificity for predicting IBL ≥ 1000 mL or PBL ≥500 mL. The incidence of red blood cell transfusion in the postoperative period was higher in patients showing MCFFIB-C ≥ 29% (34% vs 8%, P = .015).The change rate between pre- and postoperative MCFFIB values was correlated well with the amount of IBL or PBL. Moreover, particular change rate of MCFFIB could predict massive bleeding in revision THA.

Freeze-dried and irradiated allograft bone combined with fresh autologous coagula promotes angiogenesis in an ectopic bone allograft implantation model

BACKGROUND

Freeze-dried and irradiated allograft bone (FIAB) is more easily impacted than fresh-frozen allograft bone (FAB), but has weaker incorporation efficiency. We combined FIAB with fresh autologous coagula to enhance donor-host incorporation after impaction during hip revision.

METHODS

Thirty adult male Sprague-Dawley (SD) rats were sacrificed for bone allograft harvesting, and nine male rats were subjected to ectopic bone allograft implantation. For each rat, the container on the left (study) side was filled with freeze-dried allograft bone powder and fresh autologous blood coagula, whereas the right (control) side was filled with freeze-dried allograft bone powder and physiological saline. The extent of angiogenesis (VEGFα) was investigated at postoperative weeks 1, 4, and 8. The deformability of the material was evaluated by performing a confined-impaction mechanical test.

RESULTS

At postoperative weeks 4 and 8, angiogenesis within FIAB on the left side was more pronounced than that on the right side. At postoperative week 1, the left side showed significantly higher VEGFα expression than that on the right side. The delta ratios of compression of the allografts were found to be influenced by bone height and impaction frequency, but not by stiffness or elastic modulus (EM).

CONCLUSION

Supplementation with fresh autologous coagula promoted angiogenesis within the FIABs. Moreover, FIABs were equivalent to FABs in terms of deformability.

FIBTEM provides prediction of massive bleeding in total hip replacement arthroplasty

This retrospective study evaluated the association between maximum clot firmness of FIBTEM (MCFFIB) and blood loss, and determined a cutoff value of MCFFIB that may predict massive bleeding in total hip replacement arthroplasty (THRA). Seventy-two adult patients undergoing THRA for avascular necrosis of the femoral head or degenerative arthritis of the hip were included. Patients' medical records were reviewed to collect pre and postoperative laboratory data, as well as the amount of intra and postoperative blood loss (IBL and PBL). Each pre and postoperative fibrinogen level had a significant correlation with the pre and postoperative MCFFIB, respectively (ρ = 0.289, P = 0.014 and ρ = 0.286, P = 0.015). IBL had significant correlations with pre and postoperative MCFFIB (ρ = -0.305, P = 0.010 and ρ = -0.297, P = 0.013, respectively), and PBL also showed significant correlations with the pre and postoperative MCFFIB (ρ = -0.471, P < 0.001 and ρ = -0.475, P < 0.001, respectively). A respective pre or postoperative MCFFI cutoff value of 16 mm or less or 10 mm or less showed the highest sensitivity and specificity for predicting IBL 1000 ml or above or PBL 400 ml or above. Postoperative transfusion was performed more frequently in patients showing postoperative MCFFIB 10 mm or less (31 vs. 3.3%, P = 0.005). MCFFIB correlated well with the amount of IBL or PBL. In addition, a particular value of pre or postoperative MCFFIB could offer the predictive standard for massive bleeding in THRA.

Complications Are Not Increased With Acetabular Revision of Metal-on-metal Total Hip Arthroplasty

BACKGROUND

Isolated revision of the acetabular component in the setting of total hip arthroplasty has an increased risk of dislocation. With local soft tissue destruction frequently associated with failed metal-on-metal (MoM) bearings, it is presumed that acetabular revision of these hips will have even greater risk of complications. However, no study directly compares the complications of MoM with metal-on-polyethylene (MoP) acetabular revisions.

QUESTIONS/PURPOSES

In the context of a large database analysis, we asked the following questions: (1) Are there differences in early medical or wound complications after isolated acetabular revision of MoM and MoP bearing surfaces? (2) Are there differences in the frequency of dislocation, deep infection, and rerevision based on the bearing surface of the original implant?

METHODS

A review of the 100% Medicare database from 2005 to 2012 was performed using International Classification of Diseases, 9th Revision and Current Procedural Terminology codes. We identified 451 patients with a MoM bearing and 628 patients with a MoP bearing who had an isolated acetabular revision and a minimum followup of 2 years. The incidence, odds ratios, and 95% confidence intervals for early medical or wound complications were calculated using a univariate analysis at 30 days with patient sex and age group-adjusted analysis for blood transfusion. The incidence, odds ratio, and 95% confidence intervals for dislocation, deep infection, and rerevision were calculated using a univariate analysis at 30 day, 90 days, 1 year, and 2 years using a subgroup analysis with the Cochran-Mantel-Haenszel test to adjust for patient gender and age groups.

RESULTS

There were no differences between the MoM and MoP isolated acetabular revisions in the incidence of 30-day local complications. There was a greater risk of transfusion in the MoP group than the MoM group (134 of 451 [30%] versus 230 of 628 [37%]; odds ratio [OR], 0.731; 95% confidence interval [CI], 0.565-0.948; p = 0.018). There were no differences at 2 years between the MoM and MoP acetabular revisions in the incidence of dislocation, infection, or rerevision. When analyzed by patient sex and age group, there were more infections in the age 70 to 79 years MoP group compared with MoM (10 of 451 [5%] versus 29 of 628 [10%]; OR, 4.47; CI, 1.699-11.761; p = 0.001).

CONCLUSIONS

There were high rates of dislocation, infection, and rerevision in both revision cohorts. The rate of dislocation was not greater after acetabular revision of MoM bearings at 2 years. Based on these findings, clinicians should counsel these patients preoperatively about the risks of these complications. Dual-mobility and constrained components have specific advantages and disadvantages in these settings and should be further studied.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Revision total hip arthroplasty in the United States: national trends and in-hospital outcomes

PURPOSE

With the increasing number of primary total hip arthroplasties (THA) being performed, the frequency of revision surgery is also expected to increase. We analysed the immediate in-hospital complications and epidemiologic data of 3,469 revision and 18,186 primary THA cases.

METHODS

The National Hospital Discharge Survey (NHDS) was evaluated between 2001 and 2010 for patients who underwent revision and primary THA. Patients were identified and included in our retrospective study based on ICD-9 procedure codes.

RESULTS

The number of primary and revision THAs increased steadily from 2001 to 2010. The revision burden decreased for the same studied period (r = -0.92) to reach 13.9 % in 2010. The South region had higher revision burden of 17.4 % (p < 0.001). The primary THA group was more likely to be obese, morbidly obese, and have hypertension (p < 0.001). The revision THA group had an increased rate of blood transfusions (p < 0.001), deep venous thrombosis (p = 0.008), post-operative sepsis (p < 0.001), and wound complications (p < 0.001). The in-hospital mortality rate was also higher for the revision THA group (0.6 % versus 0.2 %, p < 0.001).

CONCLUSIONS

The revision burden has undergone a steady decrease over the ten years studied and the reason for this is likely multifactorial. The South region had a significantly higher revision burden when compared to the rest of the United States. Larger hospitals tend to perform relatively more revisions. Revision THA patients are associated with longer hospital stay, higher complications rate, and higher in-hospital mortality rate.

Reduced Blood Loss and Transfusion Rates: Additional Benefits of Local Infiltration Anaesthesia in Knee Arthroplasty Patients

We hypothesised that local infiltration of anaesthesia (LIA) containing adrenaline may reduce peri-operative blood loss and transfusion requirements in primary total knee arthroplasty patients (TKA) when compared to simple patient control analgesia (PCA). In this retrospective cohort study there were 22 TKAs in the PCA group and 27 TKAs in the LIA group. There were no drains used or significant differences in demographics between groups. There was a statistically significant difference in blood loss (P = 0.003), between the LIA group (M = 942 ml, CI 829-1055), and the PCA group (M = 1314 ml, CI 1099-1527). Patients receiving PCA were 4.3 times more likely to require blood transfusion. Using the LIA technique reduces blood loss and risk of blood transfusion.

Removal of well-fixed components in femoral revision arthroplasty with controlled segmentation of the proximal femur

Background

The transfemoral and the extended trochanteric osteotomies are the most common osteotomies used in femoral revision, both when proximal or diaphyseal fixation of the new component has been decided. We present an alternative approach to the trochanteric osteotomies, most frequently used with distally fixated stems, to overcome their shortcomings of osteotomy migration and nonunion, but, most of all, the uncontrollable fragmentation of the femur.

Methods

The procedure includes a complete circular femoral osteotomy just below the stem tip to prevent distal fracture propagation and a subsequent preplanned segmentation of the proximal femur for better exposure and fast removal of the old prosthesis. The bone fragments are reattached with cerclage wires to the revision prosthesis, which is safely anchored distally. A modified posterolateral approach is used, as the preservation of the continuity of the abductors, the greater trochanter, and the vastus lateralis is a prerequisite.

Results

Between 2006 and 2012, 47 stems (33 women, 14 men, mean age 68 years, range 39–88 years) were revised using this technique. They were 12 (26%) stable and 35 (74%) loose prostheses and were all revised to tapered, fluted, grit-blasted stems. No fracture of the trochanters or the distal femur occurred intraoperatively. Mean follow-up was 28 months (range 6–70 months). No case of trochanteric migration or nonunion of the osteotomies was recorded. Restoration of the preexisting bone defects occurred in 83% of the patients. Three patients required repeat revision due to dislocation and one due to a postoperative periprosthetic fracture. None of the failures was attributed to the procedure itself.

Conclusions

This new osteotomy technique may seem aggressive at first, but, at least in our hands, has effectively increased the speed of the femoral revision, particularly for the most difficult well-fixed components, but not at the expense of safety.

Is total hip arthroplasty a successful and safe procedure in Jehovah's Witnesses? Mean five-year results

Total hip arthroplasty (THA) can be challenging in Jehovah's Witnesses because of the potential for blood loss. Because these patients will not accept blood transfusions, multiple strategies to prevent blood loss have been developed. The purpose of this study was to report implant survivorship, clinical outcomes, radiographic outcomes, morbidity, and mortality of Jehovah's Witnesses undergoing primary THA. Databases from two institutions were reviewed to identify 53 patients (55 hips) who were Jehovah's Witnesses and had a primary total hip arthroplasty. There were 27 women and 26 men who had a mean age of 63 years (range 35-94 years), and a mean follow-up of 63 months (range 24-120 months). All Jehovah's Witnesses had a comprehensive perioperative blood management strategy employed by a coordinated medical and surgical team. Mean post-operative Harris Hip Scores were 86 points, and implant survivorship was 97%. There were two aseptic revisions for osteolysis and component loosening. There were no mortalities, and three minor surgical and two minor medical complications occurred during the study. Excellent clinical outcomes were found for Jehovah's Witness undergoing total hip arthroplasty using a comprehensive blood management protocol. We believe that the use of a specialised blood management protocol involving a team approach to preoperative evaluation, appropriate anaesthesia, and surgical and postoperative management was responsible for minimising complications. Total hip arthroplasty is safe and efficacious in this patient group if proper preoperative safeguards are utilised.

Intraoperative blood salvage in revision total hip arthroplasty: who benefits most?

The purpose of the present study was to identify factors that predict reinfusion following intraoperative blood salvage (IOBS). We retrospectively identified 298 patients who underwent aseptic revision total hip arthroplasty at our institution between February 2005 and January 2007. Of these, 160 (53.7%) received reinfusion from IOBS. In the reinfusion group, an average of 850 mL (range, 300-4300) of fluid was collected and an average of 270 mL (range, 135-1350) of red blood cells was returned. Exchange of both the femoral and acetabular components, use of a trochanteric osteotomy, increased body mass index, and advanced age were associated with reinfusion. Based on these results, surgeons may consider using IOBS on patients with these preoperative characteristics.

Effectiveness of an autologous transfusion system following cemented and non-cemented revisions of total hip arthroplasty

PURPOSE

The goal of this study was to analyse the efficacy of blood autotransfusion using a continuous autologous transfusion system in revisions of total hip arthroplasty (THA). We looked at whether administration of allogeneic blood units was reduced in these cases and if there is a difference between cemented and non-cemented revisions.

METHODS

Between January 2011 and December 2011, patients being treated with revision THA were included (n = 411). The following parameters were analysed: patient age, gender, weight (kg), height (cm), body mass index (BMI, kg/m(2)), surgical diagnosis, treatment and American Society of Anesthesiologists (ASA) classification score. The difference between pre- and post-operative haemoglobin (Hb, g/dl), amount of peri-operative blood loss (ml), amount of retransfused washed shed blood and amount of allogeneic and/or autologous transfusion (ml) were recorded.

RESULTS

In both the cemented and non-cemented revision THA groups, there was no significant difference between pre- and post-operative Hb with or without using an autotransfusion system. In 92 of 186 cemented cases using an autologous transfusion system (49.5%) and 38 of 117 non-cemented cases using an autologous transfusion system (32.5%), allogeneic blood transfusion (ABT) was required. Cemented procedures using an autologous transfusion system got significantly more ABTs than non-cemented procedures using an autologous transfusion system (p = 0.0042, odds ratio = 2.035).

CONCLUSIONS

Use of an autologous transfusion system did not reduce the amount of ABT in revision THA in the patient cohort reported here. In our opinion, general blood management is required before and during surgery to reduce administration of ABT.

Use of a bipolar sealer in total hip arthroplasty: medical resource use and costs using a hospital administrative database

Perioperative blood loss during total hip arthroplasty (THA) increases patient morbidity, length of stay (LOS), medical resource use (MRU), and costs. Minimizing blood loss may reduce postoperative anemia, the need for blood transfusions, and the increased risk of infections and longer hospital stays associated with blood transfusions. Pharmacologic agents and bipolar sealer devices can minimize perioperative bleeding. A retrospective, comparative cohort study in the US hospital setting was conducted to assess MRU and associated costs and the incidence of transfusion and complications among patients undergoing THA with or without the use of a bipolar sealer. Using a nationwide all-payer hospital administrative database, THA procedures from January 1, 2008, to March 31, 2011, were identified using International Classification of Diseases, Ninth Revision, Clinical Modification procedure code 81.51. The bipolar sealer cohort (n=2683) and matched control cohort (n=2683) had a mean age of 65 years from 38 hospitals. The 2 groups had similar incidences of pre-operative anemia and medical comorbidities. Patients in the bipolar sealer group required significantly fewer blood transfusions (21.3% vs 23.8%; P=.0286) and had significantly lower incidence of hematomas (0.2% vs 0.9%; P=.0015) and significantly shorter LOS (2.90 vs 3.31 days; P<.0001) overall. The bipolar sealer group had higher supply costs, which were offset by reduced hospital inpatient room and board and operating room costs; there was no significant difference in total hospital costs between the 2 groups ($18,937 vs $18,734; P=.56). A bipolar sealer decreases postoperative blood transfusions and LOS during primary THA without increasing total hospital costs.

Predicting length of stay from an electronic patient record system: a primary total knee replacement example

Background

To investigate whether factors can be identified that significantly affect hospital length of stay from those available in an electronic patient record system, using primary total knee replacements as an example. To investigate whether a model can be produced to predict the length of stay based on these factors to help resource planning and patient expectations on their length of stay.

Methods

Data were extracted from the electronic patient record system for discharges from primary total knee operations from January 2007 to December 2011 (n = 2,130) at one UK hospital and analysed for their effect on length of stay using Mann-Whitney and Kruskal-Wallis tests for discrete data and Spearman’s correlation coefficient for continuous data. Models for predicting length of stay for primary total knee replacements were tested using the Poisson regression and the negative binomial modelling techniques.

Results

Factors found to have a significant effect on length of stay were age, gender, consultant, discharge destination, deprivation and ethnicity. Applying a negative binomial model to these variables was successful. The model predicted the length of stay of those patients who stayed 4–6 days (~50% of admissions) with 75% accuracy within 2 days (model data). Overall, the model predicted the total days stayed over 5 years to be only 88 days more than actual, a 6.9% uplift (test data).

Conclusions

Valuable information can be found about length of stay from the analysis of variables easily extracted from an electronic patient record system. Models can be successfully created to help improve resource planning and from which a simple decision support system can be produced to help patient expectation on their length of stay.

Potential cost saving of Epoetin alfa in elective hip or knee surgery due to reduction in blood transfusions and their side effects: a discrete-event simulation model

Objectives

Transfusion of allogeneic blood is still common in orthopedic surgery. This analysis evaluates from the perspective of a German hospital the potential cost savings of Epoetin alfa (EPO) compared to predonated autologous blood transfusions or to a nobloodconservationstrategy (allogeneic blood transfusion strategy)during elective hip and knee replacement surgery.

Methods

Individual patients (N = 50,000) were simulated based on data from controlled trials, the German DRG institute (InEK) and various publications and entered into a stochastic model (Monte-Carlo) of three treatment arms: EPO, preoperative autologous donation and nobloodconservationstrategy. All three strategies lead to a different risk for an allogeneic blood transfusion. The model focused on the costs and events of the three different procedures. The costs were obtained from clinical trial databases, the German DRG system, patient records and medical publications: transfusion (allogeneic red blood cells: €320/unit and autologous red blood cells: €250/unit), pneumonia treatment (€5,000), and length of stay (€300/day). Probabilistic sensitivity analyses were performed to determine which factors had an influence on the model's clinical and cost outcomes.

Results

At acquisition costs of €200/40,000 IU EPO is cost saving compared to autologous blood donation, and cost-effective compared to a nobloodconservationstrategy. The results were most sensitive to the cost of EPO, blood units and hospital days.

Conclusions

EPO might become an attractive blood conservation strategy for anemic patients at reasonable costs due to the reduction in allogeneic blood transfusions, in the modeled incidence of transfusion-associated pneumonia andthe prolongedlength of stay.

Behaviour of perioperative values of haemoglobin, haematocrit and red blood cells in elderly patients undergoing lower limb arthroplasty: a retrospective cohort study on non-transfused patients

Little is known on how elderly patients recover pre-operative haemoglobin, haematocrit and red blood cell levels after total hip and knee arthroplasties. In this study we aimed to evaluate blood loss and recovery blood levels in relation to gender, type of surgery and preoperative haemoglobin values. We conducted a retrospective cohort study on 187 patients over 65 years of age who underwent total knee or total hip arthroplasty between January 2008 and December 2009. Preoperative blood analysis was carried out within 40 days prior to intervention followed by a 15-day postoperative follow-up. Haemoglobin recovery values in anaemic patients versus healthy patients was also estimated. All tested values decreased significantly during the first 3-5 postoperative days. Haemoglobin levels decreased statistically significantly more in males than in females, while no significant differences were observed for haematocrit and erythrocytes. Recovery of haemoglobin values did not differ significantly between healthy patients and patients with preoperative haemoglobin below 120 g/L. Furthermore, our data showed a higher blood loss in total hip arthroplasty, whilst recovery rates showed to be higher after a total knee arthroplasty procedure. In conclusion, the type of intervention and gender played an important role in blood loss and recovery rates in total joint arthroplasty.

Do revised hip resurfacing arthroplasties lead to outcomes comparable to those of primary and revised total hip arthroplasties?

BACKGROUND

A theoretical clinical advantage of hip resurfacing (HR) is the preservation of femoral bone. HR femoral component revision reportedly yields postoperative function comparable to that of primary THA. However, few studies have looked at the outcome of both HR femoral and acetabular side revisions.

QUESTIONS/PURPOSES

We determined whether (1) patients undergoing HR revision to THA have perioperative measures and outcome scores comparable to those of patients undergoing primary THA or revision of primary THA and (2) patients undergoing HR revision of both components have perioperative measures and outcome scores comparable to those of patients undergoing HR revision of the femoral component only.

METHODS

We retrospectively reviewed and compared 22 patients undergoing revision HR to a THA to a matched (age, sex, BMI) group of 23 patients undergoing primary THA and 12 patients undergoing primary THA revision. Patients completed the WOMAC and SF-12 questionnaires before surgery and at latest followup (range, 24-84 months for HR revision, 28-48 months for primary THA, and 24-48 months for revision THA). Blood loss, days in hospital, complications, and outcome scores were compared among groups.

RESULTS

We observed no differences in SF-12 scores but observed lower WOMAC stiffness, function, and total scores in the HR revision group than in the primary THA group. Patients undergoing HR revision of both components had comparable SF-12 and WOMAC stiffness, function, and total scores but overall lower WOMAC pain scores compared to patients undergoing HR revision of the femoral side only. The HR revision group had greater intraoperative blood loss compared to the primary THA group but not the revision THA group.

CONCLUSIONS

The perioperative measures and outcome scores of HR revision are comparable to those of revision THA but not primary THA. Longer followup is required to determine whether these differences persist. Patients undergoing HR revision of one or both components can expect comparable stiffness and function.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

On stabilization of loosened hip stems via cement injection into osteolytic cavities

BACKGROUND

Cement injection into osteolytic areas around the cement mantle is a technique for refixation of loose hip implants for patients who cannot undergo standard revision surgery. Preliminary clinical results show the improvement in walking distance, patients' independence and pain relief.

METHODS

In this study, we use a detailed finite element model to analyze whether cement injection into osteolytic areas contributes to the overall implant stability. We study the effect of various factors, like location and size of osteolytic areas, interface conditions and bone stiffness on bone-cement relative motion.

FINDINGS

Presented results demonstrate that the procedure is most effective for the osteolytic areas located in the proximal region of the femur, while factors like a thin layer of residual fibrous tissue around the injected cement, that was not removed during the surgery, combined with reduced bone stiffness reduce the efficiency of the procedure.

INTERPRETATION

Cement injection is able to stabilize loosened hip prostheses. However, it is important to remove the fibrous tissue layer completely, as even a thin layer will negatively influence stabilization. We will focus our research efforts on developing fibrous tissue removal techniques in order to optimize this minimally invasive treatment.