Majd Tarabichi

Osteoarthritis classification scales: Interobserver reliability and arthroscopic correlation

BACKGROUND Osteoarthritis of the knee is commonly diagnosed and monitored with radiography. However, the reliability of radiographic classification systems for osteoarthritis and the correlation of these classifications with the actual degree of confirmed degeneration of the articular cartilage of the tibiofemoral joint have not been adequately studied. METHODS As the Multicenter ACL (anterior cruciate ligament) Revision Study (MARS) Group, we conducted a multicenter, prospective longitudinal cohort study of patients undergoing revision surgery after anterior cruciate ligament reconstruction. We followed 632 patients who underwent radiographic evaluation of the knee (an anteroposterior weight-bearing radiograph, a posteroanterior weight-bearing radiograph made with the knee in 45° of flexion [Rosenberg radiograph], or both) and arthroscopic evaluation of the articular surfaces. Three blinded examiners independently graded radiographic findings according to six commonly used systems-the Kellgren-Lawrence, International Knee Documentation Committee, Fairbank, Brandt et al., Ahlbäck, and Jäger-Wirth classifications. Interobserver reliability was assessed with use of the intraclass correlation coefficient. The association between radiographic classification and arthroscopic findings of tibiofemoral chondral disease was assessed with use of the Spearman correlation coefficient. RESULTS Overall, 45° posteroanterior flexion weight-bearing radiographs had higher interobserver reliability (intraclass correlation coefficient = 0.63; 95% confidence interval, 0.61 to 0.65) compared with anteroposterior radiographs (intraclass correlation coefficient = 0.55; 95% confidence interval, 0.53 to 0.56). Similarly, the 45° posteroanterior flexion weight-bearing radiographs had higher correlation with arthroscopic findings of chondral disease (Spearman rho = 0.36; 95% confidence interval, 0.32 to 0.39) compared with anteroposterior radiographs (Spearman rho = 0.29; 95% confidence interval, 0.26 to 0.32). With respect to standards for the magnitude of the reliability coefficient and correlation coefficient (Spearman rho), the International Knee Documentation Committee classification demonstrated the best combination of good interobserver reliability and medium correlation with arthroscopic findings. CONCLUSIONS The overall estimates with the six radiographic classification systems demonstrated moderate (anteroposterior radiographs) to good (45° posteroanterior flexion weight-bearing radiographs) interobserver reliability and medium correlation with arthroscopic findings. The International Knee Documentation Committee classification assessed with use of 45° posteroanterior flexion weight-bearing radiographs had the most favorable combination of reliability and correlation. LEVEL OF EVIDENCE Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Predictors of Revision Surgery After Primary Anterior Cruciate Ligament Reconstruction

Background: Revision anterior cruciate ligament (ACL) reconstruction surgery occurs in 5% to 15% of individuals undergoing ACL reconstruction. Identifying predictors for revision ACL surgery is of essence in the pursuit of creating adequate prevention programs and to identify individuals at risk for reinjury and revision. Purpose: To determine predictors of revision ACL surgery after failed primary ACL reconstruction. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 251 participants (mean age ± SD, 26.1 ± 9.9 years) who had undergone primary ACL reconstruction 1 to 5 years earlier completed a comprehensive survey to determine predictors of revision ACL surgery at a mean 3.4 ± 1.3 years after the primary ACL reconstruction. Potential predictors that were assessed included subject characteristics (age at the time of surgery, time from injury to surgery, sex, body mass index, preinjury activity level, return to sport status), details of the initial injury (mechanism; concomitant injury to other ligaments, menisci, and cartilage), surgical details of the primary reconstruction (Lachman and pivot shift tests under anesthesia, graft type, femoral drilling technique, reconstruction technique), and postoperative course (length of rehabilitation, complications). Univariate and multivariate logistic regression analyses were performed to identify factors that predicted the need for revision ACL surgery. Results: Overall, 21 (8.4%) subjects underwent revision ACL surgery. Univariate analysis showed that younger age at the time of surgery (P = .003), participation in sports at a competitive level (P = .023), and double-bundle ACL reconstruction (P = .024) predicted increased risk of revision ACL surgery. Allograft reconstructions also demonstrated a trend toward greater risk of revision ACL surgery (P = .076). No other variables were significantly associated with revision ACL surgery. Multivariate analysis revealed that revision ACL surgery was only predicted by age at the time of surgery and graft type (autograft vs allograft). Conclusion: The overall revision ACL surgery rate after primary unilateral ACL reconstruction was 8.4%. Univariate predictors of revision ACL reconstruction included younger age at the time of surgery, competitive baseline activity level, and double-bundle ACL reconstruction. However, multivariable logistic regression analysis indicated that age and reconstruction performed with allograft were the only independent predictors of revision ACL reconstruction.

Diagnosis of Streptococcus canis periprosthetic joint infection: the utility of next-generation sequencing

A 62-year-old man who had undergone a primary knee arthroplasty 3 years earlier, presented to the emergency department with an infected prosthesis. He underwent prosthesis resection. All cultures failed to identify the infecting organism. Analysis of the intraoperative samples by next-generation sequencing revealed Streptococcus canis (an organism that resides in the oral cavity of dogs). It was later discovered that the patient had sustained a dog scratch injury several days earlier. The patient reports that his dog had licked the scratch. Treatment was delivered based on the sensitivity of S. canis, and the patient has since undergone reimplantation arthroplasty.

All Patients Should Be Screened for Diabetes Before Total Joint Arthroplasty

BACKGROUND Diabetes is highly prevalent in patients with osteoarthritis before total joint arthroplasty and presents a higher risk of adverse postoperative outcomes. However, the rate of diabetes in this population and optimal screening strategies remain unknown. METHODS We prospectively screened patients undergoing elective total joint arthroplasty for diabetes using glycated hemoglobin (HbA1c) and fasting blood glucose (FBG) levels. Screening was conducted within 2 time periods between 2012 and 2017. The prevalence of diabetes was assessed using a previous diagnosis of diabetes or, in the absence of diagnosis, by measuring if HbA1c ≥ 6.5% or FBG ≥ 126 mg/dL. Prediabetes was defined as 5.7% ≤ HbA1c ≤ 6.4% or 100 mg/dL ≤ FBG ≤ 125 mg/dL. Occurrence of a 90-day periprosthetic joint infection and wound complications was noted. RESULTS A total of 1461 patients were included in the study. The prevalence of diabetes was 20.6%; 178 patients (59.1%) had diagnosed diabetes, and 123 patients (40.9%) had undiagnosed diabetes. Prediabetes was identified in 559 patients (38.3%), resulting in a combined total of 860 (58.9%) patients with diabetes and prediabetes. Total diabetic rates were significantly higher in patients aged >65 years, of nonwhite ethnicity, and undergoing total knee arthroplasty. No significant differences in periprosthetic joint infection and wound complications were observed while comparing patients with diagnosed and undiagnosed diabetes. CONCLUSION A significant proportion of patients with undiagnosed diabetes and prediabetes were identified. Preadmission testing provides an opportunity to identify and address this condition, potentially reducing short-term arthroplasty-related complications and avoiding long-term systemic diabetic complications. We strongly recommend universal glycemic screening to all elective arthroplasty patients.

Serum Fructosamine: A Simple and Inexpensive Test for Assessing Preoperative Glycemic Control

Background: Although the medical community acknowledges the importance of preoperative glycemic control, the literature is inconclusive and the proper metric for assessment of glycemic control remains unclear. Serum fructosamine reflects the mean glycemic control in a shorter time period compared with glycated hemoglobin (HbA1c). Our aim was to examine its role in predicting adverse outcomes following total joint arthroplasty. Methods: Between 2012 and 2013, we screened all patients undergoing total joint arthroplasty preoperatively using serum HbA1c, fructosamine, and blood glucose levels. On the basis of the recommendations of the American Diabetes Association, 7% was chosen as the cutoff for HbA1c being indicative of poor glycemic control. This threshold correlated with a fructosamine level of 292 &mgr;mol/L. All patients were followed and total joint arthroplasty complications were evaluated. We were particularly interested in retrieving details on surgical-site infection (superficial and deep). Patients with fructosamine levels of ≥292 &mgr;mol/L were compared with those with fructosamine levels of <292 &mgr;mol/L. Complications were evaluated in a univariate analysis followed by a stepwise logistic regression analysis. Results: A total of 829 patients undergoing primary total joint arthroplasty were included in the present study. There were 119 patients (14.4%) with a history of diabetes and 308 patients (37.2%) with HbA1c levels in the prediabetic range. Overall, 51 patients had fructosamine levels of ≥292 &mgr;mol/L. Twenty patients (39.2%) had a fructosamine level of ≥292 &mgr;mol/L but did not have an HbA1c level of ≥7%. Patients with fructosamine levels of ≥292 &mgr;mol/L had a significantly higher risk for deep infection (adjusted odds ratio [OR], 6.2 [95% confidence interval (CI), 1.6 to 24.0]; p = 0.009), readmission (adjusted OR, 3.0 [95% CI, 1.1 to 8.1]; p = 0.03), and reoperation (adjusted OR, 3.4 [95% CI, 1.2 to 9.2]; p = 0.02). In the current study with the given sample size, HbA1c levels of ≥7% failed to show any significant correlation with deep infection (p = 0.14), readmission (p = 1.0), or reoperation (p = 0.7). Conclusions: Serum fructosamine is a simple and inexpensive test that appears to be a good predictor of adverse outcome in patients with known diabetes and those with unrecognized diabetes or hyperglycemia. Our findings suggest that fructosamine can serve as an alternative to HbA1c in the setting of preoperative glycemic assessment. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Management of the Infected Total Knee Arthroplasty

There are now several approaches to the infected knee, but complete eradication of infection seems to be near impossible. The treatment protocols include incision and drainage, immediate exchange, and two-stage reimplantation. There are multiple modifications to these approaches that do help to decrease the overall incidence of infection.

General Assembly, Diagnosis, Pathogen Isolation: Proceedings of International Consensus on Orthopedic Infections

One or more of the authors of this paper have disclosed potential or pertinent conflicts of interest, which may include receipt of payment, either direct or indirect, institutional support, or association with an entity in the biomedical field which may be perceived to have potential conflict of interest with this work. For full disclosure statements refer to https://doi.org/10.1016/j.arth.2018.09.072. 1 Question 3. 2 Question 2. 3 Question 4. 4 Question 1.

Weighing in on Body Mass Index and Infection After Total Joint Arthroplasty: Is There Evidence for a Body Mass Index Threshold?

Background Although morbid obesity is considered a modifiable risk factor for periprosthetic joint infection (PJI), there is no consensus regarding an appropriate threshold for body mass index (BMI) above which a high risk for infection may outweigh the benefits of surgery. Questions/purposes (1) Is there a BMI cutoff threshold that is associated with increased risk for PJI? (2) Is the risk of PJI increased in higher obesity classes? Methods A retrospective study was conducted of all primary THAs and TKAs performed at one institution between 2006 and 2015. Overall 19,226 patients were eligible to be included in the study; 1053 patients were excluded as a result of incomplete data, resulting in a final cohort of 18,173 patients (8757 TKAs and 9416 THAs). PJI was defined using the International Consensus Meeting criteria. To ensure accurate followup, and because there is evidence to support the association between obesity and early infection, we identified PJI within 90 days of the index surgery. This relationship was examined separately for BMI as a continuous variable and for each BMI category as defined by the Centers for Disease Control and Prevention (underweight ⩽ 18.49 kg/m2; normal 18.5-24.9 kg/m2; overweight 25-29.9 kg/m2; obese class I 30-34.9 kg/m2; obese class II 35-39.9 kg/m2; obese class III ≥ 40 kg/m2). Analyses were performed with logistic regression, accounting for both patient and surgical risk factors. A BMI threshold was evaluated with a receiver operating characteristic (ROC) curve and the Youden index. Results The area under the ROC curve for BMI and risk of PJI within 90 days was only 0.58 (confidence interval [CI], 0.52-0.63) suggesting such a cutoff was not much better than random chance. Among the BMI classes, patients with class III obesity (≥ 40 kg/m2) were the only ones showing a higher risk for PJI within 90 days (odds ratio [OR], 3.09 [1.46-6.54]; p = 0.003). The risk of developing PJI was not greater for overweight (OR, 0.72; 95% CI, 0.38-1.4), class I obese (OR, 1.06; 95% CI, 0.57-2.0), or class II obese (OR, 1.08; 95% CI, 0.52-2.2) patients. Underweight patients also demonstrated no increased risk for PJI (OR, 1.80; 95% CI, 0.23-13.9). Conclusions The risk for infection increases gradually throughout the full range of BMI, but no threshold exists. Weight reduction before surgery may mitigate risk for infection for all patients with a BMI above normal. Of note, patients with a BMI > 40 kg/m2 carried a threefold higher risk for PJI and for these patients, the risks of surgery must be carefully weighed against its benefits. Level of Evidence Level III, therapeutic study.