Elective Total Hip Arthroplasty Patients Research Articles

Evaluation of the Effectiveness of Canadian Cardiovascular Society Guidelines in Minimizing Cardiac Events After Total Hip Arthroplasty

IntroductionThe aim of the study was to analyze the Canadian Cardiovascular Society (CCS) guidelines for routine postoperative troponin testing after elective total hip arthroplasty (THA) to reduce the mortality rate resulting from myocardial injury. The purpose of this study was to assess the prognostic relevance of implementing these guidelines to minimize cardiac events in patients undergoing elective THA. MethodsPatients who underwent THA surgery in 2020 were included in the study. The inclusion criteria were elective THA patients aged ≥ 45 years, while emergency, revision, and simultaneous bilateral THA surgeries were excluded. The patients were categorized into four groups based on the CCS guidelines. ResultsThe study included 669 patients who had an average age of 67 years. There were forty-three patients (6.4%), who experienced a rise in troponin levels ≥ 30 ng/L and developed myocardial injury after noncardiac surgery (MINS). Among these patients, eight developed cardiac complications, and one experienced a serious cardiac event that resulted in death. Notably, there was a significant increase in the length of hospital stay for patients who received the postoperative screening protocol. ConclusionThe implementation of the CCS guidelines for routine postoperative troponin testing in elective THA surgery did not significantly decrease the rate of cardiac events or mortality.

Role of femoral head material on readmission and mortality rates following elective primary total hip arthroplasty in Medicare patients.

The role of different femoral head materials for total hip arthroplasty (THA) has been widely studied in the context of wear properties and corrosion. Cobalt chrome (CoCr) femoral heads are commonly used as a standard of comparison to other materials such as ceramic and oxidized zirconium (OxZi). This study aims to evaluate the impact of femoral head material on clinical outcomes in elective primary THA patients. Retrospective analysis of THA patients within the Medicare claims database between October 2017 and September 2020 using diagnosis-related group codes was conducted. Information collected included sex, age, Charlson Comorbidity Index, and femoral head type. Patients with CoCr femoral heads were compared against patients with either OxZi or ceramic femoral heads using 1:1 propensity score matching. Z-testing and Chi-square analysis were used to determine between-group significance. In total, 112,960 elective THA patients were included, with 56,480 in OxZi or ceramic and 56,480 in CoCr. Readmission rates were lower in patients that received OxZi or ceramic femoral heads at 30-day (p < 0.0001), 60-day (p < 0.0001), and 90-day postoperatively (p < 0.0001) compared to CoCr. Mortality rates were also lower in patients that received OxZi or ceramic femoral heads at 30-day (p = 0.004), 60-day (p = 0.018), and 90-day postoperatively (p = 0.009) compared to CoCr. CoCr femoral heads had higher rates of readmissions and mortality compared to OxZi or ceramic. Further analysis of bearing surface combinations and sub-group analyses to determine significance between-group differences is needed. Retrospective analysis.

Incidence of Symptomatic Venous Thromboembolism (VTE) in 8,885 Elective Total Hip Arthroplasty Patients Receiving Post-operative Aspirin VTE Prophylaxis.

Venous thromboembolism (VTE) is a potentially reducible cause of morbidity and mortality in patients undergoing elective hip arthroplasty surgery. The balance of post-operative VTE prophylaxis and risk of post-operative haemorrhage remains at the forefront of surgeon's mind. The National Institute for Health and Care Excellence (NICE) published updated guidelines in 2018 which recommend the use of both mechanical and pharmacological methods in patients undergoing elective total hip arthroplasty (THA). The aim of this study was to present the symptomatic VTE incidence in 8,885 patients who underwent THA between January 1998 and March 2018 with Aspirin as the primary agent for pharmacological thromboprophylaxis. Intermittent calf compression stockings are routinely used from the time of surgery until mobilization (usually the following day) with prophylactic doses of low molecular weight heparin (LMWH) during inpatient stay (from 2005 onwards) and then Aspirin 150mg once daily for six weeks on hospital discharge (or Aspirin only prior to 2005), with use of other therapies occasionally as required. Analysis of prospective data collection from consecutive patients at a single institution undergoing THA was performed with the incidence of symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) occurring within six months of the index operation as the primary outcome measure. Ninety-day all-cause mortality of this cohort of patients was also analysed. 8,885 patients were reviewed. This included 7230 primary, 224 complex primary and 1431 revision cases. The overall incidence of symptomatic VTE after elective THA was 1.11% (99/8885) - with the incidence of symptomatic DVT of 0.59% (52/8885) and the incidence of symptomatic PE of 0.53% (47/8885). There was no significant difference (χ2 test, p=0.239) in the symptomatic VTE incidence between primary (1.20% - 89/7230), complex primary (0.89% - 2/224) and revision cases (0.70% - 10/1431). The 90-day all-cause mortality was 0.88% (78/8885). Cardiovascular and respiratory disease were the main causes of death following surgery. Only 0.03% of deaths (n= 3) within 90 days of index surgery were due to PE. There was no significant difference (p=0.327) in length of stay (and hence amount of pharmacologic prophylaxis with LMWH received by patients before commencement of Aspirin) with the average length of stay for those patients who did not suffer a VTE of 6.8 days compared with 7.6 days for those who did suffer a VTE. Our results support the use of aspirin as an effective form of prophylaxis against symptomatic VTE following THA in contradiction to NICE and American Academy of Orthopaedic Surgery (AAOS) recommendations. It is not associated with an increased incidence in symptomatic DVT, PE or death compared to other published studies. The fact that it is inexpensive, readily available, requires no monitoring and does not pose an increased risk of bleeding are other advantages of using aspirin for VTE prophylaxis.

Systemic Effects of Trauma and Trauma-Derived Exosomes on Bone Marrow Function

INTRODUCTION: Severe trauma disrupts bone marrow (BM) function and is associated with persistent anemia and immunosuppression. Exosomes are extracellular vesicles that have been implicated in disease, cellular functions, and immunomodulation. The effects of trauma plasma-derived exosomes on BM hematopoiesis have not been studied; we hypothesized that trauma plasma-derived exosomes would suppress BM function. METHODS: Plasma was collected from a prospective, cohort study of trauma patients (n = 15) with hip and/or femur fractures and an Injury Severity Score greater than 15; elective total hip arthroplasty patients (n = 11) served as operative controls. Exosomes were isolated from plasma with the Invitrogen Total Exosome Isolation Kit. Healthy BM was cultured with either 2% plasma, 50 µg, 100 µg, or 200 µg of exosomal protein and BM progenitor growth (CFU-GEMM, BFU-E, and CFU-GM) assessed. Differences were compared using the Mann-Whitney t-test, with significance defined as p < 0.05 vs total hip arthroplasty. RESULTS: Trauma patients were significantly younger than total hip arthroplasty patients (mean 44 vs 61 years), with no difference in sex between groups. In vitro exposure to 2% trauma plasma significantly decreased growth of all BM progenitors (Table). In vitro exposure to 50 µg did not affect BM progenitor growth; 100 µg and 200 µg of trauma exosomal protein significantly decreased growth of BFU-E (22% and 14%) and CFU-GM (12% and 13%). Table. - Cohort CFU-GEMM (/50k Plated Cells) BFU-E (/50k Plated Cells) CFU-GM (/50k Plated Cells) 2% THA plasma 18 ± 3 39 ± 2 46 ± 5 50 µg THA exosomal protein 18 ± 3 23 ± 2 51 ± 2 100 µg THA exosomal protein 19 ± 1 22 ± 3 51 ± 5 200 µg THA exosomal protein 22 ± 2 22 ± 3 47 ± 6 2% trauma plasma 15 ± 3* 29 ± 6* 40 ± 7* 50 µg trauma exosomal Protein 17 ± 3 19 ± 4 47 ± 5 100 µg trauma exosomal protein 20 ± 3 17 ± 2* 45 ± 6* 200 µg trauma exosomal protein 22 ± 2 19 ± 1* 41 ± 4* *p < 0.05.THA, total hip arthroplasty. CONCLUSION: Both plasma and plasma-derived exosomes from trauma patients adversely affect BM function. Systemic effects of plasma-derived exosomes may contribute to altered hematopoiesis after severe trauma; further analysis of exosomal content may improve our understanding of altered BM function.

The combined effect of policy changes and the covid-19 pandemic on the same day discharge and complications following total hip arthroplasty: a nationwide analysis

IntroductionAs a result of the SARS-CoV-2 (COVID-19) pandemic in 2020, elective surgeries, including total joint arthroplasty (TJA), were suspended nationwide. Concurrent removal of total hip arthroplasty (THA) from the Medicare inpatient-only list posed challenges to the delivery of quality patient care with low payor cost. Therefore, the objective of this study was to compare temporal trends in patient demographics, case volumes, length of stay, and complications following elective THA in the years 2019 to 2020 in the United States.MethodsThe 2019 to 2020 ACS-NSQIP database was queried for elective THA patients. Patients Pre-COVID (2019 and 2020Q1) were compared with post-COVID (2020Q2-Q4). THA utilization, demographics, 30-day complications, and length of stay (LOS) were compared between years. Linear regression evaluated changes in case volumes over time with significance threshold of P < 0.05.ResultsA total of 77,797 patients underwent elective THA in 2019 (n = 43,667) and 2020 (n = 34,130), resulting in a 24.5% decline. Outpatient THA increased in 2020 (35.6%) vs. 2019 (5.7%) (P < 0.001). There was no significant difference in the volume of cases in 2019Q1 through 2019Q4 (P = 0.984). Elective THA volumes declined by 68.8% in 2020Q2, returned to pre-pandemic baseline in 2020Q3, before leveling off at 81.5% of baseline in Q4. Average LOS was significantly shorter in 2020 (1.55 days) vs. 2019 (1.78 days) (P < 0.001) and the proportion of same day discharge (SDD) increased quarterly from 2019 to 2020. There was no significant difference in the total complication rates in 2019 (6.6%) vs. 2020 (6.6%) (P = 0.831).DiscussionElective THA precipitously declined during the second quarter of 2020. The combined effect of policy changes and the COVID-19 pandemic resulted in a seven-fold increase in the number of surgeries performed in the outpatient setting in 2020. Rates of SDD doubled over the study period, despite no change in complication rates.

Revision Risk in a Cohort of US Patients Younger Than 55 Undergoing Primary Elective Total Hip Arthroplasty.

As indications for elective total hip arthroplasty (THA) expand to younger patients, we sought to (1) compare revision risk following primary elective THA in patients <55 years at the time of their THA to patients aged ≥65 years and (2) identify specific risk factors for revision in patients <55 years. A Kaiser Permanente's total joint replacement registry was used to conduct a cohort study including primary elective THA patients aged ≥18 (2001-2018). In total, 11,671 patients <55 years and 53,106 patients ≥65 years were included. Multiple Cox regression was used to evaluate cause-specific revision risk, including septic revision, aseptic loosening, instability, and periprosthetic fracture. Stepwise Cox regression was used to identify patient and surgical factors associated with cause-specific revision in patients <55 years. Patients <55 years had a higher risk of septic revision (hazard ratio [HR]= 1.30, 95% confidence interval [CI]= 1.02-1.66), aseptic loosening (HR= 2.60, 95% CI= 1.99-3.40), and instability (HR= 1.35, 95% CI= 1.09-1.68), but a lower risk of revision for periprosthetic fracture (HR= 0.36, 95% CI= 0.22-0.59) compared to patients aged ≥65 years. In the <55 age group, risk factors for septic revision included higher body mass index, drug abuse, and liver disease. Hypertension, anterior approach, and ceramic-on-ceramic were associated with aseptic loosening. White race, American Society of Anesthesiologists classification ≥3, smoker, paralysis, posterior approach, ceramic-on-ceramic, and smaller head diameter were associated with instability. Identified risk factors varied depending on the cause for revision. Although septic revisions were related to patient characteristics, more modifiable factors, such as implant or surgical approach, were associated with revision due to aseptic loosening and instability. III.

Perioperative amino acid infusion reestablishes muscle net balance during total hip arthroplasty.

Surgery and anesthesia induce a catabolic response that leads to skeletal muscle protein loss. Previous investigations have observed positive effects of perioperative nutrition. Furthermore, the benefits of exogenous amino acids on muscle protein kinetics are well established. However, no investigation has focused on muscle protein kinetics with and without perioperative amino acid infusion. Thus, we aimed to assess the effect of perioperative amino acid (AA) infusion on muscle protein balance in individuals undergoing elective total hip arthroplasty (THA). Elective THA patients were randomized to undergo a metabolic study prior to surgery (n = 5; control [CON]), intraoperative AA infusion (n = 9), or no AA (n = 13; standard of care [SC]). The CON group was studied prior to surgery to provide nonoperative/non‐anesthesia muscle protein kinetic reference values. The bolus infusion method with 13C6‐phenylalanine injected at time 0, and [15N]‐phenylalanine 30 min later was used to calculate muscle protein synthesis (MPS), protein breakdown (MPB), and net balance (MPS−MPB). Perioperative AA significantly improved muscle net balance as compared to SC (−0.005 ± 0.018%/h vs. −0.052 ± 0.011%/h) but not CON (0.003 ± 0.013%/h). The AA infusion significantly increased muscle net balance via a significant increase in MPS (AA = 0.062 ± 0.007%/h; SC = 0.037 ± 0.004%/h; CON = 0.072% ± 0.005%/h), and a nonsignificant attenuation of MPB (AA = 0.067 ± 0.012%/h; SC = 0.089 ± 0.014%/h; CON = 0.075 ± 0.011%/h). Our data support the use of perioperative AA infusion during elective THA as pragmatic strategy to offset the loss of surgically induced skeletal muscle protein.

Transmuscular Quadratus Lumborum and Lateral Femoral Cutaneous Nerve Block in Total Hip Arthroplasty.

Adequate pain control after total hip arthroplasty is essential for patient satisfaction and surgical outcome. A retrospective study with before and after design was performed in 210 elective total hip arthroplasty patients. The control group (N=132) received spinal anesthesia with periarticular injection (PAI) and the treatment group (N=78) received transmuscular quadratus lumborum block and lateral femoral cutaneous nerve block in addition to spinal anesthesia and PAI. The primary outcome was visual analog scale (VAS) pain score on postoperative day (POD) 1, and secondary outcomes included VAS and opioid consumption on each POD, hospitalization cost, length of stay, and discharge acuity. The mean VAS and opioid consumption (MME) were significantly lower in the treatment group than that in the control group on POD 1, with VAS difference -1.10 (95% confidence interval, -1.64 to -0.55), false discover rate corrected (P<0.001), and MME difference -26.19 (95% confidence interval, -39.16 to -13.23, P<0.001). A significant difference was also found for both VAS (P=0.007) and opioid consumption (P=0.018) on POD 2 and for opioid consumption on POD 3 (P=0.008). Length of stay (days) in the control group versus the treatment group was 2.50±1.38 versus 1.36±0.95 (P=0.002), and the total cost of hospitalization was over 20% higher in the control group than that in the treatment group (P=0.002). The addition of transmuscular quadratus lumborum and lateral femoral cutaneous nerve block in total hip arthroplasty provides improved analgesia indicated by lower pain scores and opioid reduction and accelerated recovery with shorter hospitalization and decreased hospitalization cost.

Tranexamic acid in non-elective primary total hip arthroplasty.

Blood loss during and following elective total hip arthroplasty (THA) can be substantial and may require allogeneic blood transfusions which carries significant risks and morbidity for patients. Intraoperative use of tranexamic acid (TXA) has been proven to reduce the need for allogeneic blood transfusion in elective THA patients. Data regarding TXA efficacy in reducing blood loss in trauma patients undergoing non-elective primary THA is sparse, and its routine use is not well established. This is a retrospective analysis of a consecutive cohort of patients who underwent non-elective primary THA in a tertiary medical center between January 1st 2011- December 31st 2019. The cohort was divided into two groups; one received perioperative TXA treatment while the other did not. Blood loss, blood product administration, peri and postoperative complications, readmissions and 1-year mortality were compared between groups. A total of 419 patients (146 males, 273 females) who underwent THA were included in this study. The "TXA" group consisted 315 patients compared to 104 patients in the "no TXA" group. TXA use reduced postoperative bleeding, as indicated by changes in hemoglobin levels before and after surgery (ΔHb= -2.75 gr/dL vs. ΔHb= -3.34 gr/dL,p<0.001) and by administration of allogeneic blood transfusions (7.0% vs. 16.3%,p=0.004). Similar to the known effect of TXA in elective THA patients, the use of TXA treatment in patients undergoing non-elective THA led to a significant reduction in postoperative blood loss and in the proportion of patients requiring allogeneic blood transfusions.

Is continuation of anti-platelet treatment safe for elective total hip arthroplasty patients?

Acetylsalicylic acid (aspirin) is a commonly prescribed medication, especially in the age group of individuals who undergo elective total hip arthroplasty (THA). Preoperative discontinuation of aspirin is believed to reduce intraoperative bleeding and other complications, but it may increase the risk of perioperative cardiovascular events. In this study we have sought to evaluate the safety of continuous aspirin treatment in patients undergoing elective THA. This is a retrospective analysis of a consecutive cohort who underwent elective THA in a tertiary medical center between 2011 and 2018. The cohort was divided into two groups-one that received continuous preoperative aspirin treatment and one that did not. Blood loss, peri- and postoperative complications, readmissions, and short- and long-term mortality were compared between groups. Out of 757 consecutive patients (293 males, 464 females) who underwent elective primary THA, 552 were in the "non-aspirin" group and 205 were in the "aspirin" group and were not treated preoperative with other medication affecting hemostasis. Perioperative continuation of aspirin treatment did not significantly increase perioperative bleeding, as indicated by changes in hemoglobin levels (P = 0.72). There were no significant differences in short- and long-term mortality (P = 0.47 and P = 0.4, respectively) or other perioperative complications, such as readmission (P = 0.78), deep or superficial infection (P = 1 and P = 0.47, respectively), and cardiovascular events (none in both groups). Peri-operative continuation of aspirin treatment in patients undergoing elective primary THA did not increase perioperative complications or mortality compared to the non-aspirin-treated patients. The protective effects of aspirin from postoperative thrombotic and cardiovascular events are well documented. The current findings dispute the need to preoperatively withhold aspirin treatment in patients undergoing elective primary THA.

Target Price Adjustment for Hip Fractures Is Not Sufficient in the Bundled Payments for Care Improvement Initiative

BackgroundUnder the Bundled Payments for Care Improvement (BPCI) initiative, the Centers for Medicare and Medicaid Services (CMS) adjusts the target price for total hip arthroplasty (THA) based upon the historical proportion of fracture cases. Concerns exist that hospitals that care for hip fracture patients may be penalized in BPCI. The purpose of this study is to compare the episode-of-care (EOC) costs of hip fracture patients to elective THA patients. MethodsWe reviewed a consecutive series of 4096 THA patients from 2015 to 2018. Patients were grouped into elective THA (n = 3686), fracture THA (n = 176), and hemiarthroplasty (n = 274). Using CMS claims data, we compared EOC costs, postacute care costs, and performance against the target price between the groups. To control for confounding variables, we performed a multivariate analysis to identify the effect of hip fracture diagnosis on costs. ResultsElective THA patients had lower EOC ($18,200 vs $42,605 vs $38,371; P < .001) and postacute care costs ($4477 vs $28,093 vs $23,217; P < .001) than both hemiarthroplasty and THA for fracture. Patients undergoing arthroplasty for fracture lost an average of $23,122 (vs $1648 profit for elective THA; P < .001) with 91% of cases exceeding the target price (vs 20% for elective THA; P < .001). In multivariate analysis, patients undergoing arthroplasty for fracture had higher EOC costs by $19,492 (P < .001). ConclusionPatients undergoing arthroplasty for fracture cost over twice as much as elective THA patients. CMS should change their methodology or exclude fracture patients from BPCI, particularly during the COVID-19 pandemic.

The Impact of Chronic Obstructive Pulmonary Disease and Hospital Teaching Status on Mortality, Cost, and Length of Stay in Elective Total Hip Arthroplasty Patients.

IntroductionTotal hip arthroplasty (THA) is a frequently performed surgery. Chronic obstructive pulmonary disease (COPD) is one of the most prevalent diseases in the United States and has been associated with higher complications in many orthopedic surgeries. The purpose of this study was to examine the clinical and economic impacts of COPD on the mortality, cost, and length of stay of those undergoing THA and the effect of hospital teaching status on these outcomes.MethodsThis retrospective cohort study identified adult patients (≥18 years) utilizing information from the Healthcare Cost and Utilization Program Nationwide Inpatient Sample (NIS) from 2012 to 2014 undergoing elective THA using ICD-9 codes. Patients missing key clinical identifiers or those who did not undergo THA were excluded. Mortality, cost, and length of stay were assessed. The COPD cohort was further analyzed by hospital teaching status, including urban teaching, urban non-teaching, and rural.ResultsAn adjusted total of 7,652 patients with COPD and 768,000 patients without COPD undergoing THA were identified. COPD was associated with higher mortality rates, longer lengths of stay, and total charges. In the COPD cohort, teaching status did affect outcomes. Between urban teaching hospitals and urban non-teaching, chronic conditions were significantly higher in urban teaching hospitals, yet total charges were lower. LOS was longer in rural hospitals, however, all other variables, including costs, were not significantly different as compared to urban teaching hospitals. Between urban non-teaching hospitals and rural hospitals, the number of chronic conditions and LOS were higher in rural hospitals, yet costs were significantly less. Age and mortality rates were not significantly different between different teaching statuses.ConclusionCOPD has a significant effect on mortality, length of stay, and cost in patients undergoing THA. Additionally, teaching status seems to play an interesting role in these variables. Preoperative planning may help surgeons mitigate some of these risks associated with COPD. Further work on how LOS and costs are optimized with regards to teaching status should be done.

Re-admissions treble the risk of late mortality after primary total hiparthroplasty.

Following a total hip arthroplasty (THA), early hospital re-admission rates of 3-11% are considered as 'acceptable' in terms of medical care cost policies. Surprisingly, the impact of re-admissions on mortality has not been priorly portrayed. Therefore, we sought to determine the mortality rate after 90-day re-admissions following a THA in a series of patients from a captive medical care program. We prospectively analysed 90-day readmissions of 815 unilateral, elective THA patients operated upon between 2010 and 2014 whose medical care was the one offered by our institution. We stratified our sample into readmitted and non-readmitted cohorts. Through a Cox proportional hazards model, we compared demographic characteristics, clinical comorbidities, surgical outcomes and laboratory values between both groups in order to determine association with early and late mortality. We found 37 (4.53%) re-admissions at a median time of 40.44days (IQR 17.46-60.69). Factors associated with re-admission were hospital stay (p = 0.00); surgical time (p = 0.01); chronic renal insufficiency (p = 0.03); ASA class 4 (p = 0.00); morbid obesity (p = 0.006); diabetes (p = 0.04) and a high Charlson index (p = 0.00). Overall mortality rate of the series was 3.31% (27/815). Median time to mortality was 455.5days (IQR 297.58-1170.65). One-third (11/37) of the re-admitted patients died, being sepsis non-related to the THA the most common cause of death. After adjusting for confounders, 90-day re-admissions remained associated with mortality with an adjusted HR of 3.14 (CI95% 1.05-9.36, p = 0.04). Unplanned re-admissions were an independent risk factor for future mortality, increasing three times the risk of mortality.

Does the Timing of Pre-Operative Medical Evaluation Influence Perioperative Total Hip Arthroplasty Outcomes?

Background:Medical evaluation pre-operatively is an important component of risk stratification and potential risk optimization. However, the effect of timing prior to surgical intervention is not well-understood. We hypothesized that total hip arthroplasty (THA) patients seen in pre-operative evaluation closer to the date of surgery would experience better perioperative outcomes.Methods:We retrospectively reviewed 167 elective THA patients to study the relationship between the number of days between pre-operative evaluation (range, 0-80 days) and surgical intervention. Patients’ demographics, length of stay (LOS), ICU admission frequency, and rate of major complications were recorded.Results:When pre-operative evaluation carried out 4 days or less before the procedure date, there was a significant reduction in LOS (3.91 vs. 4.49; p=0.03). When pre-operative evaluation carried out 11 days or less prior to the procedure date, there was a four-fold decrease in rate of intensive care admission (p=0.04). Furthermore, the major complication rate also significantly reduced (p<0.05). However, when pre-operative evaluation took place 30 days or less before the procedure date compared to more than 30 days prior, there were no significant changes in the outcomes.Conclusion:From this study, pre-operative medical evaluation closer to the procedure date was correlated with improved selected peri-operative outcomes. However, further study on larger patient groups must be done to confirm this finding. More study is needed to define the effect on rare events like infection, and to analyze the subsets of THA patients with modifiable risk factors that may be time-dependent and need further time to optimization.

A Comparison of Collagen Crosslink Content in Bone Specimens from Elective Total Hip Arthroplasty Patients with and without Type 2 Diabetes

Objective: To compare the amount of non-enzymatic and enzymatic collagen crosslinks in bone specimens from total hip replacement patients with and without type 2 diabetes (controls). Methods: This ex vivo cross-sectional study included 34 bone specimens (13 from patients with type 2 diabetes, 21 from controls) from men and women ≥ 65 years. All participants were undergoing an elective total hip replacement due to osteoarthritis. Cancellers cores were extracted from the interior of the femoral neck/head and bone cores were reduced to approximately 50 mg of powder. High performance liquid chromatography (HPLC) was used to quantify pentosidine, pyridinoline (PYD) and deoxypyridoline (DPD), which were normalized to collagen content. The mean (SD) was calculated for continuous variables and an independent Student’s t-test was used to compare crosslink content between groups. Results: 13 specimens were collected from participants with type 2 diabetes (mean [SD] age 73.8 [6.2] years) and 21 specimens were collected from controls (mean [SD] age 76.7 [6.8] years, p=0.222). There was no between-group difference in the amount of bone pentosidine (type 2 diabetes: 2.07 [0.94] mmol/mol collagen vs. control: 1.99 [0.60] mmol/mol collagen, p=0.753), PYD (type 2 diabetes: 219.2 [25.3] mmol/mol collagen vs. control: 208.1 [25.8] mmol/mol collagen, p=0.227) or DPD (type 2 diabetes: 132.3 [25.9] mmol/mol collagen vs. control: 130.0 [22.8] mmol/mol collagen, p=0.787). Conclusion: Elective total hip replacement patients with and without type 2 diabetes have similar collagen crosslink profiles. Future studies should consider potential confounding factors, such as bone turnover rate, which may influence collagen crosslink content.

Muscle inflammation susceptibility: a prognostic index of recovery potential after hip arthroplasty?

While elective total hip arthroplasty (THA) for end-stage osteoarthritis (OA) improves pain, mobility function, and quality of life in most cases, a large proportion of patients suffer persistent muscle atrophy, pain, and mobility impairment. Extensive skeletal muscle damage is unavoidable in these surgical procedures, and it stands to reason that poor recovery and long-term mobility impairment among some individuals after THA is linked to failed muscle regeneration and regrowth following surgery and that local muscle inflammation susceptibility (MuIS) is a major contributing factor. Here we present results of two integrated studies. In study 1, we compared muscle inflammation and protein metabolism signaling in elective THA (n=15) vs. hip fracture/trauma (HFX; n=11) vs. nonsurgical controls (CON; n=19). In study 2, we compared two subgroups of THA patients dichotomized into MuIS⁺ (n=7) or MuIS⁻ (n=7) based on muscle expression of TNF-like weak inducer of apoptosis (TWEAK) receptor (Fn14). As expected, HFX demonstrated overt systemic and local muscle inflammation and hypermetabolism. By contrast, no systemic inflammation was detected in elective THA patients; however, local muscle inflammation in the perioperative limb was profound in MuIS⁺ and was accompanied by suppressed muscle protein synthesis compared with MuIS⁻. Muscle from the contralateral limb of MuIS⁺ was unaffected, providing evidence of a true inflammation susceptibility localized to the muscle surrounding the hip with end-stage OA. We suggest MuIS status assessed at the time of surgery may be a useful prognostic index for muscle recovery potential and could therefore provide the basis for a personalized approach to postsurgery rehabilitation.

Impact of body mass on hospital resource use in total hip arthroplasty

To determine the impact of BMI on post-operative outcomes and resource utilization following elective total hip arthroplasty (THA). A retrospective cohort analysis on all primary elective THA patients between 1996 and 2004. Primary outcomes investigated using regression analyses included length of stay (LOS) and costs (US dollars). Mayo Clinic Rochester, a tertiary care centre. Patients were stratified by pre-operative BMI as normal (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), obese (30.0-34.9 kg/m(2)) and morbidly obese (> or =35.0 kg/m(2)). Of 5642 patients, 1362 (24.1 %) patients had a normal BMI, 2146 (38.0 %) were overweight, 1342 (23.8 %) were obese and 792 (14.0 %) were morbidly obese. Adjusted LOS was similar among normal (4.99 d), overweight (5.00 d), obese (5.02 d) and morbidly obese (5.17 d) patients (P = 0.20). Adjusted overall episode costs were no different (P = 0.23) between the groups of normal ($17,211), overweight ($17,462), obese ($17,195) and morbidly obese ($17,655) patients. Overall operative and anaesthesia costs were higher in the morbidly obese group ($5688) than in normal ($5553), overweight ($5549) and obese ($5593) patients (P = 0.03). Operating room costs were higher in morbidly obese patients ($3418) than in normal ($3276), overweight ($3291) and obese ($3340) patients (P < 0.001). Post-operative costs were no different (P = 0.30). Blood bank costs differed (P = 0.002) and were lower in the morbidly obese group ($180) compared with the other patient groups (P < 0.05). Other differences in costs were not significant. Morbidly obese patients were more likely to be transferred to a nursing home (24.1 %) than normal (18.4 %), overweight (17.9 %) or obese (16.0 %) patients (P = 0.001 each). There were no differences in the composite endpoint of 30 d mortality, re-admissions, re-operations or intensive care unit utilization. BMI in patients undergoing primary elective THA did not impact LOS or overall institutional acute care costs, despite higher operative costs in morbidly obese patients. Obesity does not increase resource utilization for elective THA.