William P. Urban

Predictors of Septic Arthritis in the Adult Population

Septic arthritis is a devastating condition; well-established criteria for diagnosis exist in the pediatric population, but not for adults. This study evaluated patient factors and laboratory parameters that may be associated with the diagnosis of septic arthritis in adults. A total of 458 knee aspirates for suspected septic arthritis were evaluated with serum and synovial leukocyte counts and differentials as well as Kocher criteria for pediatric septic arthritis. Twenty-two patients (4.8%) had septic arthritis confirmed by a positive synovial fluid culture. Erythrocyte sedimentation rate (ESR) and serum white blood cell (WBC) counts were not statistically different between the 2 groups, with 64% of septic arthritis patients having a normal serum WBC count and 77% being afebrile. Mean synovial fluid WBC count was 26,758 cells/µL and 70,581 cells/µL in the nonseptic and septic groups, respectively. The likelihood ratio for a synovial fluid WBC count greater than 65,000 cells/µL was 2.8 (95% confidence interval, 1.2-6.7). Evaluation receiver operating characteristic curves using synovial WBC counts resulted in a significant area under the curve of 0.66 (P=.02). To achieve 90% specificity, a WBC cutoff of 64,000 cells/µL was required with a corresponding sensitivity of 40%. There was no significant difference in the synovial cell differential of 80% vs 90% in diagnosing infection. Synovial fluid WBC count greater than 64,000 cells/µL yielded the optimal combination of sensitivity and specificity. Polymorphonuclear leukocytes, ESR, serum WBC count, fever, and weight-bearing status were not significant predictors of septic arthritis. This study demonstrates the limited utility of Kocher criteria in the adult population and the importance of synovial leukocyte counts. [Orthopedics. 2016; 39(4):e657-e663.].

Poster 35: Epidemiology and Trends of Surfing-Related Head Injuries that Presented to United States Emergency Departments from 2001 to 2016

Disclosures: Kevin Ong: I Have No Relevant Financial Relationships To Disclose Objective: (1) Is hylan G-F 20 associated with a delay to knee arthroplasty (KA)? (2) Does the delay to KA differ with the number of HA courses? Design: Retrospective cohort study. Setting: Optum Clinformatics data (2006-Q2 2016) with claims from about 13 million lives covered by UnitedHealth Group annually. Participants: 141,305 KA patients. Interventions: Patients who did not use IA HA (No HA group), used one type of non-hylan G-F 20 HA or multiple types of HAs (Non-hylan G-F 20 group), and used only hylan G-F 20. Main Outcome Measures: Median duration from knee OA to KA, using quantile regression with adjustment confounding factors, with propensity score weighting. Results: Overall median time from knee OA diagnosis to KA was 1.2 years. Unadjusted median time to KA for the no HA group was 0.9 years versus 2.1 years and 2.0 years for the non-hylan G-F 20 and hylan G-F 20 groups, respectively. After propensity score weighting, hylan G-F 20 and nonhylan G-F 20 patients had significantly longer times by 7.3 and 7.8 months (P < .001), respectively, than the no HA patients. 25.6% of the non-hylanG-F20groupand19.7%of thehylanG-F20groupreceivedmore than oneHAcourse. After adjusting for time to firstHAuse and number of injections, hylan G-F 20 patients had 1.7 months longer time to KA than non-hylanG-F20HApatients (P<.001). Themedian time toKA increased fromabout21months (1.8years) to59months (4.9 years) as thehylanG-F 20 group increased their treatment courses from one to five or more. Conclusions: Most KA patients did not use IA HA (73.7%), but those who did were associated with a longer median time to KA by about 7-8 months. A dose response was observed in terms of a longer time to KA with more HA courses. Level of Evidence: Level II

A Systematic Review and Meta-Analysis of Procalcitonin as a Marker of Postoperative Orthopedic Infections

Procalcitonin is a serologic marker that increases in response to inflammatory stimuli, especially those of bacterial origin. Postoperative orthopedic periprosthetic infections are often difficult to diagnose. This study systematically reviewed the literature to evaluate the statistical measures of performance of procalcitonin as a marker of postoperative orthopedic infection. This study showed that procalcitonin has a weighted pooled sensitivity of 67.3%, specificity of 69.4%, positive likelihood ratio of 1.778, negative likelihood ratio of 0.423, and diagnostic odds ratio of 5.770. These results illustrate that procalcitonin is an effective serologic marker for postoperative bacterial infections. [Orthopedics. 2018; 41(3):e303-e309.].

Knee dislocation with popliteal artery disruption: A nationwide analysis from 2005 to 2013

Objective Few have compared short-term outcomes following knee dislocations with or without concomitant popliteal artery disruption (PAD). Methods The Nationwide Inpatient Sample was used to identify 2175 patients admitted for knee dislocation from 2005 to 2013 (concomitant PAD: n = 210/9.7%; without: n = 1965/90.3%). Results Patients with PAD were younger, more often male, Black and Hispanic, and with Medicaid (all p ≤ 0.013). PADs were associated with 11.0-times higher odds of increased LOS (95%CI, 6.6-18.4) and 2.8-times higher odds of experiencing any complication (95%CI, 2.03-3.92). Female sex was a protective factor against increased LOS, (OR = 0.65; 95%CI, 0.48-0.88). Conclusion High suspicion index should be maintained for concomitant vascular injuries following knee dislocations.

The Effects of Meniscal Geometry on Susceptibility for Meniscal and ACL Injury in Non-Arthritic Knees: A Retrospective Case-Control Study

Prior studies have not found significant differences in meniscal parameters between patients with meniscal and ligamentous injury and those without. The purpose of this study was to determine whether such relationships exist. Clinical records and magnetic resonance images of three subject groups were reviewed. Group 1 solely had meniscal tears (medial/lateral), Group 2 had meniscal tears with concurrent ACL tears, and Group 3 had healthy knees. The mean age of subjects included was 35.9 years (range 8.2-72.6). The height, width, diagonal, slope, and cross-sectional area for the anterior and posterior horns of the lateral and medial menisci were assessed. Normal distribution of data was confirmed by the Shapiro-Wilk test and analysis of variance with a post hoc Tukeys test was used to assess potential differences. p < 0.05 was set as the level of significance. There was no difference between the meniscal slopes of patients with and without meniscal tears (p = 0.77-1.0). Meniscal height (p = 0.0001-0.024) and width (p = 0.0001-0.046) demonstrated significant differences in all horns. Cross-sectional area was larger in the torn group (p = 0.0001-0.012). To compare intact and torn menisci, a logistical regression model was used and found to be significantly different from the constant model (p < 0.0001). Predictive success was 80.5%. A logistical regression model was used comparing undamaged menisci with torn menisci with accompanying anterior cruciate ligament (ACL) tear and was significant (p < 0.0001). A larger cross-sectional meniscal area in both the anterior and posterior horns of both menisci was a risk factor for isolated meniscal tears and combined meniscal and ACL tears. It has been postulated that certain demographic variables, such as gender, age, and body mass index, may be risk factors associated with ACL and meniscal injuries. However, the relationship between intrinsic morphology, namely meniscal size and shape, and risk of injury is unclear. The majority of studies have focused on meniscal morphology/geometry and its association with degenerative tears in patients with end-stage osteoarthritis rather than on acute meniscoligamentous injury. In this study of non-arthritic knees, a larger cross-sectional meniscal area in both the anterior and posterior horns of both menisci was a risk factor for having both an isolated meniscal tear as well as a combined meniscal and ACL tear. With advances in the field of meniscal repair, particularly with allograft procedures, more attention should be paid to meniscal cross-sectional area because it may play a role in the natural history of knee injury.

Current Concepts in Sports-Related Concussion

Traumatic brain injury, specifically concussion, is prevalent in contact sports. In the United States (US) each year, 170 million adults participate in physical recreational activities, and 38 million children and adolescents participate in organized sports. The Centers for Disease Control estimate that in this group ~1.6 to 3.8 million concussions occur annually. Recent class-action lawsuits in the US filed by professional athletes against their respective leagues allege negligence in protecting them from concussions, and this has contributed to the attention received in the popular media. In response, concussion-related publications have increased exponentially during the past several years. Recent studies have challenged earlier assumptions that the effects of concussion are transient. Stronger links between concussion and neurodegenerative processes such as Alzheimers disease-like conditions, depression, and heightened risk for suicide are being elucidated. In this article, we explore the current knowledge on concussion, including pathophysiology, management, and long-term effects. We conclude that more evidence-based results regarding guidelines for diagnosis, treatment, and return to play (RTP) are needed and should be the focus of future investigations. Attributing the etiology of certain neurodegenerative conditions to a history of concussion has been suggested in the current literature, but additional quantitative data regarding the pathophysiology and causality are needed as well. Bioengineers can have an important role in measuring the dynamic forces encountered during head impacts and their effects on the brain. These results can be effective in designing better helmets as well as improved playing surfaces to reduce the impact of such injuries. At this time, we believe that groups of people with heightened risk for concussion should be followed closely during longer periods of time and compared to matched controls. Such long-term studies are urgently needed to develop appropriate guidelines for safety and protect our young and adult athletes in the future.