Samuel S. Wellman

Impact of perioperative allogeneic and autologous blood transfusion on acute wound infection following total knee and total hip arthroplasty.

BACKGROUND Patients undergoing total hip or knee arthroplasty frequently receive blood transfusions. The relationship between transfusion and the risk of infection following total joint arthroplasty is unclear. In this study, we sought to examine the impact of allogeneic and autologous transfusion on the risk of acute infection following total hip and total knee arthroplasty. METHODS We performed a retrospective study of consecutive primary total knee arthroplasties and total hip arthroplasties. Patients who had a reoperation for suspected infection within three months after the arthroplasty were identified. Differences in risk factors were assessed across transfusion groups: no transfusion, autologous only, and allogeneic exposure (allogeneic with or without additional autologous transfusion). Backward-stepwise logistic regression analysis was used to compare reoperations (as outcomes) between cases with and those without allogeneic exposure. Prespecified covariates were body mass index, diabetes, an American Society of Anesthesiologists (ASA) score of >2, preoperative hematocrit, and total number of units transfused perioperatively. RESULTS We identified 3352 patients treated with a total hip or knee arthroplasty (1730 total knee arthroplasties and 1622 total hip arthroplasties) for inclusion in the study. Transfusion was given in 1746 cases: 836 of them had allogeneic exposure, and 910 had autologous-only transfusion. There were thirty-two reoperations (0.95%) for suspected infection. Between-group risk-factor differences were observed. The mean age and the rates of diabetes, immunosuppression, ASA scores of >2, and bilateral surgery were highest in the allogeneic group, as were estimated blood loss, surgery duration, and total number of units transfused (p < 0.001). In the unadjusted analyses, the rate of reoperations for suspected infection was higher in the cases with allogeneic exposure (1.67%) than in those without allogeneic exposure (0.72%) (p = 0.013). Autologous-only transfusion was not associated with a higher reoperation rate. However, multivariable logistic regression demonstrated that the total number of units transfused (p = 0.011) and an ASA score of >2 (p = 0.008)-but not allogeneic exposure-were significantly predictive of a reoperation. CONCLUSIONS Perioperative allogeneic transfusion was associated with a higher rate of reoperations for suspected acute infection. However, patients with allogeneic exposure had increased infection risk factors. After adjustment for the total number of units transfused and an ASA score of >2, allogeneic exposure was not significantly predictive of a reoperation for infection.

Unicompartmental Knee Arthroplasty and Total Knee Arthroplasty Among Medicare Beneficiaries, 2000 to 2009

BACKGROUND Unicompartmental knee arthroplasty is a less-invasive alternative to total knee arthroplasty for patients with arthritis affecting only the medial or lateral compartment. However, little is known about recent trends in the use of these procedures and the associated outcomes among older patients. METHODS With use of a nationally representative 5% sample of Medicare beneficiaries who were sixty-five years of age or older and who had undergone either unilateral unicompartmental knee arthroplasty or unilateral total knee arthroplasty from 2000 to 2009, we assessed trends in the use of unicompartmental and total knee arthroplasty, associated durations of hospital stay, and postoperative outcomes. The outcome measures were the rates of implant revision or removal within five years and the rates of periprosthetic infection, thromboembolic events, myocardial infarction, and all-cause mortality within one year. We conducted Kaplan-Meier analyses to assess the cumulative incidence of unadjusted outcomes and used Cox proportional-hazards regression to understand the relative risks of the outcomes for each procedure. RESULTS A total of 68,603 patients underwent unilateral total knee arthroplasty (n = 65,505) or unilateral unicompartmental knee arthroplasty (n = 3098) from 2000 to 2009. The mean age was seventy-five years; 34% of the patients were men, and 92% were white. The procedure rate was twenty-one times higher for total knee arthroplasty (597 per 100,000 person-years) than unicompartmental knee arthroplasty (twenty-nine per 100,000 person-years). The use of total knee arthroplasty increased 1.7-fold, and the use of unicompartmental knee arthroplasty increased 6.2-fold. The mean length of stay (and standard deviation [SD]) was 3.9 ± 2.1 days for total knee arthroplasty and 2.4 ± 1.7 days for unicompartmental knee arthroplasty. The five-year revision rate was 3.7% for total knee arthroplasty and 8.0% for unicompartmental knee arthroplasty. After multivariable adjustment, the risk of revision remained 2.4 times higher for unicompartmental knee arthroplasty than for total knee arthroplasty (95% confidence interval [CI] = 2.03 to 2.83). After multivariable adjustment, patients who underwent unicompartmental knee arthroplasty had no significant differential one-year risk of infection (adjusted hazard ratio [HR] = 0.74; 95% CI = 0.55 to 1.01), thromboembolic events (adjusted HR =0.86; 95% CI = 0.57 to 1.29), or mortality (adjusted HR = 0.75; 95% CI = 0.50 to 1.11). CONCLUSIONS Although unicompartmental knee arthroplasty accounted for only 4.5% of the unilateral knee replacements among Medicare beneficiaries, the use of this procedure has increased dramatically. Compared with those who had total knee arthroplasty, patients who underwent unicompartmental knee arthroplasty had higher revision rates but shorter durations of stay and tended to have lower rates of perioperative complications. These findings need to be confirmed by studies that incorporate detailed clinical information.

Pseudotumor with superimposed periprosthetic infection following metal-on-metal total hip arthroplasty: A case report

Second-generation metal-on-metal bearing surfaces made of modern cobalt-chromium-molybdenum alloys are widely used for total hip arthroplasty in the United States1. While these bearing surfaces offer considerable advantages over conventional metal-on-polyethylene articulations, metal hypersensitivity reactions to these implants are an important, although uncommon, cause of failure2. This unique mode of failure, which has been reported with first-generation implants2,3 and subsequently in association with second-generation metal-on-metal bearing surfaces, appears to be caused by an immunologic delayed hypersensitivity response to metal particles4-6. This local tissue reaction, described as an aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL), was characterized by Willert et al.7 as having histologic features that include diffuse perivascular infiltrates of T and B lymphocytes and plasma cells, high endothelial venules, massive fibrin exudation, accumulation of macrophages with droplike inclusions, and infiltrates of eosinophilic granulocytes and necrosis. Histologically, high endothelial venules are characterized as vascular and/or lymphatic vessels with reactive endothelium, often seen in association with an inflammatory response. Willert et al. suggested that the possibility of such a reaction be considered when, following primary implantation of metal-on-metal implants, a patient reports the recurrence of preoperative pain and there is a marked joint effusion or the development of osteolysis in the absence of a suspicion of deep periprosthetic infection. A subsequent report, however, described this hypersensitivity reaction mimicking infection in a patient with elevated levels of inflammatory biomarkers who was later found to have no deep infection on revision8. We describe a patient with a failure of a metal-on-metal total hip replacement consistent with a metal hypersensitivity reaction who presented with a pseudotumor and massive lower-extremity edema secondary to extrinsic femoral vein compression and subsequently developed a superimposed deep periprosthetic infection prior to revision. To our knowledge, this has not …

Patient expectation is the most important predictor of discharge destination after primary total joint arthroplasty.

The purpose of this study was to identify preoperative predictors of discharge destination after total joint arthroplasty. A retrospective study of three hundred and seventy-two consecutive patients who underwent primary total hip and knee arthroplasty was performed. The mean length of stay was 2.9 days and 29.0% of patients were discharged to extended care facilities. Age, caregiver support at home, and patient expectation of discharge destination were the only significant multivariable predictors regardless of the type of surgery (total knee versus total hip arthroplasty). Among those variables, patient expectation was the most important predictor (P < 0.001; OR 169.53). The study was adequately powered to analyze the variables in the multivariable logistic regression model, which had a high concordance index of 0.969.

The Association of ASA Class on Total Knee and Total Hip Arthroplasty Readmission Rates in an Academic Hospital

Total hip and knee arthroplasties are two of the most successful orthopaedic procedures. However, with the increasing demand, estimated future costs for these procedures are enormous. Recent data suggest post-discharge care may account for up to 35% of total episode payments. Yet, little is known about targets that can help improve quality and reduce cost. This retrospective study shows an ASA score of ≥ 3 is associated with a 2.9 times (P = 0.0082) greater risk of re-admission in total joint arthroplasty patients. The current literature corroborates this finding by demonstrating an increase risk of post-operative complications in patients with an ASA of ≥ 3. Therefore, the ASA score is a potential target for interventions designed to increase quality and lower cost in arthroplasty patients.

Simultaneous vs Staged Bilateral Total Knee Arthroplasty Among Medicare Beneficiaries, 2000–2009

Simultaneous bilateral total knee arthroplasty (TKA) reportedly has higher postoperative complication rates than staged procedures, but little is known about recent trends and outcomes among Medicare patients. In a 5% national sample of Medicare beneficiaries older than 65 years, we identified 83,441 patients who underwent elective TKA between 2000 and 2009 and compared patients undergoing simultaneous bilateral TKA (n=4519) to staged TKA (n=3788). Use of simultaneous TKA did not change over time (3 in 10,000), but use of staged TKA increased three-fold from 1.4 to 4.4 in 10,000 person-years. We assessed length of stay; 5-year risk of revision; periprocedural (i.e., 90-day) risk of infection; hospitalization for venous thromboembolism (VTE) and myocardial infarction (MI); and death using Kaplan-Meier methods. Simultaneous TKA had higher 90-day risk of death (0.7% vs. 0.3%, P=0.02), VTE (0.9% vs. 0.5%, P=0.07), and MI (0.5% vs. 0.2%, P=0.02). Infection and revision rates were similar between the two groups.

Implementation of an accelerated mobilization protocol following primary total hip arthroplasty: impact on length of stay and disposition

With improvements in surgical techniques, implant design, and patient caremaps, surgeons have sought to accelerate early rehabilitation after total hip arthroplasty. Many authors have reported results of fundamentally similar protocols to achieve this end. These protocols focus on multi-modal pain management, early therapy, tissue-preserving surgical technique, and careful blood management. We present the implementation and results of such a protocol involving a different surgical approach, and highlight the published literature on this topic.

Outcomes after Total Knee Arthroplasty for post-traumatic arthritis.

INTRODUCTION Total Knee Arthroplasty (TKA) is an important treatment for posttraumatic arthritis (PTA), but evidence on outcomes is sparse. The purpose of this study was to evaluate the impact of PTA versus primary osteoarthritis (OA) on postoperative outcomes after TKA. METHODS We queried the entire Medicare database from 2005 to 2012. International Classification of Diseases, 9th revision and Current Procedural Terminology codes were used to identify the procedure, indication, and complications. Patients with minimum two-years follow-up were selected. Odds ratios (ORs), confidence intervals, and p-values (p) were calculated. RESULTS For PTA, 3509 patients had TKA. For OA, 257,611 patients with TKA served as controls. The average Charlson Comorbidity Index for both groups was five. PTA patients were younger; only eight out of 29 Elixhauser comorbidities were higher. PTA patients had higher incidence of periprosthetic infection (OR 1.72, p<0.001), cellulitis or seroma (OR 1.19, p<0.001), knee wound complications (OR 1.80, p<0.001), TKA revision (OR 1.23, p=0.01), and arthrotomy/incision and drainage (OR 1.55, p<0.001). Blood transfusion rate was lower in PTA patients. There were no significant differences in bleeding complications, prosthetic dislocation, broken prostheses, periprosthetic fracture, osteolysis and polywear, neurovascular injury, and extensor mechanism rupture. DISCUSSION AND CONCLUSION This study represents, to our knowledge, TKA outcomes in the largest cohort of PTA patients to date. Our findings indicate that these patients are at higher risk for many, but not all, postoperative surgical complications despite being as healthy as patients receiving TKA for primary OA.

Percent body fat more associated with perioperative risks after total joint arthroplasty than body mass index

Understanding the impact of obesity on elective total joint arthroplasty (TJA) remains critical. Perioperative outcomes were reviewed in 316 patients undergoing primary TJA. Higher percent body fat (PBF) was associated with postoperative blood transfusion, increased hospital length of stay (LOS) >3 days, and discharge to an extended care facility while no significant differences existed for BMI. Additionally, PBF of 43.5 was associated with a 2.4× greater likelihood of blood transfusion, PBF of 36.5 with a 1.9× greater likelihood for LOS >3 days, and PBF of 36.0 with a 1.4× greater likelihood for discharge to an extended care facility. PBF may be a more effective measure than BMI to use in screening for perioperative risks and acute outcomes associated with obese total joint patients.

Risk Versus Reward: Total Joint Arthroplasty Outcomes After Various Solid Organ Transplantations

Clinical outcomes were retrospectively reviewed for 76 primary total hip (THA) and total knee arthroplasties (TKA) performed after kidney, liver, cardiac, and lung transplantation with follow-up of 30.2 and 41.2 months, respectively. For the THA and TKA cohorts, there were a high rate of medical complications (29% and 33%), increased hospital length of stay (4.2 and 3.7 days), and more reoperations (7.2% and 9.1%). Only 1 (1.8%) periprosthetic infection was documented for THAs but 3 (14.2%) TKAs required two-stage revisions for infection. All transplant cohorts demonstrated significant increases (P < 0.05) in HHS and KSS scores with majority of patients reporting overall good or excellent outcomes (82%-100%). These results suggest that various organ transplant patients may accept higher surgical risks for rewarding outcomes.