Tyler Steven Watters

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.

The Effect of Total Hip Arthroplasty Surgical Approach on Postoperative Gait Mechanics

Surgical approach for total hip arthroplasty (THA) is determined by clinician preference from limited prospective data. This study aimed to examine the effect of surgical approach (direct lateral, posterior, and anterolateral) on 6-week postoperative gait mechanics. Thirty-five patients (direct lateral, 8; posterior, 12; anterolateral, 15) were tested preoperatively and 6 weeks after THA. Patients underwent a gait analysis at a self-selected walking speed. A 2-way analysis of variance was used for analysis. Stride length, step length, peak hip extension, and walking speed increased after THA. The 3 surgical approach variables were not significantly different for any of the study variables after THA. All patients showed some increase in selected variables after THA regardless of surgical approach. In this study, surgical approach did not appear to significantly influence the early postoperative gait mechanics that were quantified.

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 …

Fixation versus replacement of radial head in terrible triad: is there a difference in elbow stability and prognosis?

BackgroundSurgical treatment for terrible triad injuries of the elbow (defined as elbow dislocations with concomitant fractures of the radial head and coronoid) remains a challenging clinical problem. Specifically, the question of whether to repair or replace the radial head remains controversial.Questions/purposesWe compared patients with terrible triad injuries of the elbow whose radial head fracture was treated with either internal fixation and internal fixation (ORIF) or radial head arthroplasty in terms of (1) clinical outcome measures (DASH and Broberg-Morrey scores, ROM), (2) elbow stability and radiographic signs of arthrosis, and (3) complications and reoperation rates.MethodsRetrospective review identified 39 patients with terrible triad injuries and minimum 18-month complete clinical and radiographic followup (mean, 24 months; range, 18–53 months). Patients were managed with a standard algorithm consisting of (1) repair (n = 9) or replacement (n = 30) of the radial head, (2) repair of the lateral ulnar collateral ligament, and (3) repair of the coronoid fracture. During the study period, the radial head generally was internally fixed when there were fewer than four articular fragments; otherwise, it was replaced. Evaluation included the DASH score, the Broberg-Morrey index, measurements of elbow stability and motion, and radiographic assessment for signs of arthrosis; chart review was performed for complications and reoperations. Complete followup was available on 87% (39 of 45 patients).ResultsThere were no differences between groups in terms of ROM or elbow scores. All patients who underwent radial head arthroplasty at the index procedure had a stable elbow at final followup whereas three of nine patients who underwent ORIF were unstable (p = 0.009). However, 11 patients who underwent arthroplasty demonstrated radiographic signs of arthrosis compared to none in the ORIF group (p = 0.04). Eleven patients (28%) underwent reoperation (seven arthroplasty, four ORIF) for various reasons. With the numbers available, there was no difference in reoperation rate between groups (p = 0.45).ConclusionsFor terrible triad injuries, radial head arthroplasty afforded the ability to obtain elbow stability with comparable overall outcomes when compared to ORIF. As these injuries commonly occur in younger patients, longer-term studies will be required to ascertain whether the apparent benefits of radial head arthroplasty are offset by late complications of arthroplasty, such as loosening.Level of EvidenceLevel III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Cost effectiveness analysis of hemiarthroplasty and total shoulder arthroplasty

BACKGROUND Total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) are two viable surgical treatment options for glenohumeral osteoarthritis. Recent systematic reviews and randomized trials suggest that TSA, while more costly initially, may have superior outcomes with regard to pain, function and quality of life with lower revision rates. This study compared the cost-effectiveness of TSA with HA. METHODS A Markov decision model was constructed for a cost-utility analysis of TSA compared to HA in a cohort of 64-year-old patients. Outcome probabilities and effectiveness were derived from the literature. Costs were estimated from the societal perspective using the national average Medicare reimbursement for the procedures in 2008 US dollars. Effectiveness was expressed in quality-adjusted life years (QALYs) gained. Principal outcome measures were average incremental costs, incremental effectiveness, incremental QALYs, and net health benefits. RESULTS In the base case, HA resulted in a lower number of average QALYs gained at a higher average cost to society and was, therefore, dominated by the TSA strategy for the treatment of glenohumeral osteoarthritis. The cost effectiveness ratio for TSA and HA were

The Use of Dual-mobility Components in Total Hip Arthroplasty

957/QALY and

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

1,194/QALY respectively. Sensitivity analysis revealed that if the utility of TSA is equal to, or revision rate lower than HA, TSA continues to be a dominant strategy. CONCLUSION Total shoulder arthroplasty with a cemented glenoid is a cost-effective procedure, resulting in greater utility for the patient at a lower overall cost to the payer. These findings suggest that TSA is the preferred treatment for certain populations from both a patient and payer perspective.

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

&NA; Dual‐mobility hip components provide for an additional articular surface, with the goal of improving range of motion, jump distance (ie, vertical or inferior head displacement required for dislocation), and stability of the total hip arthroplasty. A large polyethylene head articulates with a polished metal acetabular component, and an additional smaller metal head is snap‐fit within the polyethylene. New components have recently been released for use in North America. Although these devices are routinely used in some European centers for primary hip arthroplasty, their greatest utility may be to manage recurrent dislocation in the setting of revision hip arthroplasty. Several small retrospective series have shown satisfactory results for this indication at short‐ to midterm follow‐up. Polyethylene wear and intraprosthetic dislocation are concerns, as is the lack of long‐term data. Caution is thus advised in the routine use of dual‐mobility components in primary and revision total hip arthroplasty.

Outcomes of primary total joint arthroplasty after lung transplantation.

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.