Wael K. Barsoum

Comparison of patient-specific instruments with standard surgical instruments in determining glenoid component position: a randomized prospective clinical trial.

BACKGROUND Glenoid component malposition for anatomic shoulder replacement may result in complications. The purpose of this study was to define the efficacy of a new surgical method to place the glenoid component. METHODS Thirty-one patients were randomized for glenoid component placement with use of either novel three-dimensional computed tomographic scan planning software combined with patient-specific instrumentation (the glenoid positioning system group), or conventional computed tomographic scan, preoperative planning, and surgical technique, utilizing instruments provided by the implant manufacturer (the standard surgical group). The desired position of the component was determined preoperatively. Postoperatively, a computed tomographic scan was used to define and compare the actual implant location with the preoperative plan. RESULTS In the standard surgical group, the average preoperative glenoid retroversion was -11.3° (range, -39° to 17°). In the glenoid positioning system group, the average glenoid retroversion was -14.8° (range, -27° to 7°). When the standard surgical group was compared with the glenoid positioning system group, patient-specific instrumentation technology significantly decreased (p < 0.05) the average deviation of implant position for inclination and medial-lateral offset. Overall, the average deviation in version was 6.9° in the standard surgical group and 4.3° in the glenoid positioning system group. The average deviation in inclination was 11.6° in the standard surgical group and 2.9° in the glenoid positioning system group. The greatest benefit of patient-specific instrumentation was observed in patients with retroversion in excess of 16°; the average deviation was 10° in the standard surgical group and 1.2° in the glenoid positioning system group (p < 0.001). Preoperative planning and patient-specific instrumentation use resulted in a significant improvement in the selection and use of the optimal type of implant and a significant reduction in the frequency of malpositioned glenoid implants. CONCLUSIONS Novel three-dimensional preoperative planning, coupled with patient and implant-specific instrumentation, allows the surgeon to better define the preoperative pathology, select the optimal implant design and location, and then accurately execute the plan at the time of surgery.

Duration of anesthesia and venous thromboembolism after hip and knee arthroplasty

OBJECTIVE To determine whether longer duration of anesthesia predisposes patients undergoing orthopedic surgery to venous thromboembolism (VTE). PATIENTS AND METHODS We conducted a secondary analysis of a retrospective case-control study that examined risk factors for postoperative VTE in postmenopausal women. We matched women aged 50 years and older with radiographically confirmed postoperative VTE (cases) by age, surgeon, year of surgery, and surgical joint (knee vs hip) with women without postoperative VTE (controls). Duration of anesthesia, operative variables, demographic data, comorbid illnesses, and laboratory data were determined by medical record review. RESULTS Eighty-eight cases were matched with 181 controls. Duration of anesthesia of 3.5 hours or longer (corresponding to the upper tertile of patients) was strongly associated with postoperative VTE compared with a shorter duration of anesthesia (odds ratio, 3.58; 95% confidence Interval, 2.11-6.16; P < .001). This relationship was maintained after controlling for multiple covariates with propensity score methods, Including type of arthroplasty, route of anesthesia, type of antithrombotic prophylaxis, and surgical approach. In multivariate analysis, the Important predictors of VTE included anesthesia duration of 3.5 hours or longer, type of antithrombotic prophylaxis, revision (vs primary) arthroplasty, and allogeneic blood transfusion. CONCLUSION We found a marked association between the duration of anesthesia and postoperative VTE in patients undergoing Joint arthroplasty. Although it is possible that unmeasured intraoperative variables account for this relationship, we suggest that duration of anesthesia may be an important risk factor for postoperative VTE after orthopedic surgery.

Predicting Patient Discharge Disposition After Total Joint Arthroplasty in the United States

The purpose of this study was to develop an easily administered tool to preoperatively predict patient discharge disposition after total joint arthroplasty in the United States. Data were collected in a retrospective review of 517 medical charts and analyzed using logistic regression to develop a model for predicting the likelihood that a patient will not be discharged directly home. The resulting regression model was the basis for the nomogram, named the Predicting Location after Arthroplasty Nomogram. This model demonstrated a bootstrap-corrected concordance index of 0.867, excellent calibration, and external validation as demonstrated by a concordance index of 0.861. Preoperative knowledge that a patient is likely to require an extended care facility allows the clinical care team to make appropriate arrangements and avoid potential delays in patient discharge.

The Preoperative Prediction of Success Following Irrigation and Debridement With Polyethylene Exchange for Hip and Knee Prosthetic Joint Infections

Although the criterion standard for the treatment of prosthetic joint infections (PJIs) is 2-stage revision with interim placement of an antibiotic-loaded spacer, irrigation and debridement with polyethylene exchange offer advantages such as fewer surgeries, reduced potential for intraoperative complications, and lower direct costs. The purpose of this study was to develop a tool to preoperatively predict the probability of successful infection eradication following irrigation and debridement with polyethylene exchange for hip or knee PJIs. A total of 10,411 surgical cases were retrospectively reviewed, and data were collected from 309 charts. Overall, 149 (48.2%) cases failed to eradicate the infection following irrigation and debridement with polyethylene exchange. Univariate analysis identified multiple variables independently associated with reinfection including duration of symptoms, preoperative inflammatory markers, and infecting organism. Logistic regression was used to generate a model (bootstrap-corrected concordance index of 0.645) to predict successful eradication of the infection, which was the basis for a nomogram. Using commonly obtained preoperative variables, the nomogram can be used to predict the probability of infection-free survival at 1, 2, 3, 4, and 5 years. Preoperative knowledge of the probability that a treatment strategy will eradicate a patients PJI may improve risk assessment.

The Use of Navigation in Total Knee Arthroplasty for Patients With Extra-Articular Deformity ☆

Computer-assisted navigation for total knee arthroplasty provides high technology instrumentation that may improve the technique for restoring the normal lower limb mechanical axis. This study evaluated the use of computer-assisted navigation in 7 patients (9 total knee arthroplasties) with a radiographic femoral extra-articular deformity. Postoperatively, the mechanical axis deviated medially by a mean of 1.3 degrees +/- 0.9 degrees (range, -0.2 degrees to 2.5 degrees ). Early patient outcomes showed an increase in the average preoperative to postoperative Knee Society Scores (from 62 to 92, P < .05), function scores (from 52 to 83, P < .05), and range of motion (from 4 degrees -74 degrees to 0.6 degrees -98 degrees , P < .05). These results support the use of computer-assisted navigation as effective high technology instrumentation in recreating an acceptable mechanical axis in patients with distorted anatomical landmarks.

Allogenic Blood Transfusion Following Total Hip Arthroplasty: Results from the Nationwide Inpatient Sample, 2000 to 2009

BACKGROUND The large-scale utilization of allogenic blood transfusion and its associated outcomes have been described in critically ill patients and those undergoing high-risk cardiac surgery but not in patients undergoing elective total hip arthroplasty. The objective of this study was to determine the trends in utilization and outcomes of allogenic blood transfusion in patients undergoing primary total hip arthroplasty in the United States from 2000 to 2009. METHODS An observational cohort of 2,087,423 patients who underwent primary total hip arthroplasty from 2000 to 2009 was identified in the Nationwide Inpatient Sample. International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes 99.03 and 99.04 were used to identify patients who received allogenic blood products during their hospital stay. Risk factors for allogenic transfusions were identified with use of multivariable logistic regression models. We used propensity score matching to estimate the adjusted association between transfusion and surgical outcomes. RESULTS The rate of allogenic blood transfusion increased from 11.8% in 2000 to 19.0% in 2009. Patient-related risk factors for receiving an allogenic blood transfusion include an older age, female sex, black race, and Medicaid insurance. Hospital-related risk factors include rural location, smaller size, and non-academic status. After adjusting for confounders, allogenic blood transfusion was associated with a longer hospital stay (0.58 ± 0.02 day; p < 0.001), increased costs (

MRI and gross anatomy of the iliopsoas tendon complex

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α-Defensin Accuracy to Diagnose Periprosthetic Joint Infection—Best Available Test?

49 [in 2009 U.S. dollars]; p < 0.001), increased rate of discharge to an inpatient facility (odds ratio, 1.28; 95% confidence interval, 1.26 to 1.31), and worse surgical and medical outcomes. In-hospital mortality was not affected by allogenic blood transfusion (odds ratio, 0.97; 95% confidence interval, 0.77 to 1.21). CONCLUSIONS The increase in allogenic blood transfusion among total hip arthroplasty patients is concerning considering the associated increase in surgical complications and adverse events. The risk factors for transfusion and its impact on costs and inpatient outcomes can potentially be used to enhance patient care through optimizing preoperative discussions and effective utilization of blood-conservation methods.

The effect of patch testing on surgical practices and outcomes in orthopedic patients with metal implants.

ObjectiveThe objective was to explain the anatomic basis of a longitudinal cleft of increased signal in the iliopsoas tendon seen on hip MR arthrograms.Materials and methodsA prospective review of 20 MR hip arthrograms was performed using standard and fat-suppressed T1-weighted images to establish whether or not the cleft was composed of fatty tissue and to define the anatomy of the iliopsoas tendon complex. Three cadaver dissections of the hip region were then performed for anatomic correlation.ResultsFourteen out of 20 MR hip arthrograms demonstrated a longitudinal cleft of increased T1 signal adjacent to the iliopsoas tendon, which suppressed on frequency selective fat-suppressed images, indicating fatty composition. Gross anatomic correlation demonstrated this fatty cleft to represent a fascial plane adjacent to the iliopsoas tendon, in one case separating the iliopsoas tendon medially from a thin intramuscular tendon within the lateral portion of the iliacus muscle. Also noted was a direct muscular insertion of the lateral portion of the iliacus muscle onto the anterior portion of the proximal femoral diaphysis in all 3 cadavers.ConclusionThe anatomy of the iliopsoas tendon complex is more complicated than typically illustrated and includes the iliopsoas tendon itself attaching to the lesser trochanter, the lateral portion of the iliacus muscle attaching directly upon the anterior portion of the proximal femoral diaphysis, and a thin intramuscular tendon within this lateral iliacus muscle that is separated from the iliopsoas tendon by a cleft of fatty fascia that accounts for the MRI findings of a cleft of increased T1 signal.

Primary total knee arthroplasty allogenic transfusion trends, length of stay, and complications: nationwide inpatient sample 2000-2009.

BACKGROUND The purpose of this study was to test the accuracy of a single synovial fluid biomarker, α-defensin, in diagnosing periprosthetic joint infection in revision total hip and revision total knee arthroplasty. METHODS A total of 102 patients comprising 116 revision total hip arthroplasty and revision total knee arthroplasty procedures performed between May 2013 and March 2014 were prospectively evaluated. Cases were categorized as infected or notinfected using Musculoskeletal Infection Society criteria. Synovial fluid was obtained and tested for α-defensin using a commercially available kit (Synovasure [CD Diagnostics, Baltimore, Maryland]). RESULTS For first-stage and single-stage revisions, the α-defensin test had a sensitivity of 100% (95% confidence interval [CI], 86%-100%) and a specificity of 98% (95% CI, 90%-100%) with a positive predictive value of 96% (95% CI, 80%-99%) and negative predictive value of 100% (95% CI, 93%-100%). CONCLUSION A positive α-defensin test result was significantly more sensitive and specific for predicting infection than current diagnostic testing and should be considered when managing periprosthetic joint infection. LEVEL OF EVIDENCE Level III, Study of Diagnostic Test.