Reconstruction Plate-Based Antibiotic Cement Spacers: Clinical Outcomes and Description of Technique.

The standard of care for chronic deep peri-prosthetic hip infection is a two-stage exchange with placement of a temporary antibiotic cement spacer and treatment with intravenous antibiotics. Several commercially available cement spacer options exist. We report on a novel antibiotic spacer that may be an efficient, cost-effective alternative. Medical records of all patients treated for deep peri-prosthetic hip infection after total hip arthroplasty between 2004 and 2012 were reviewed. Each antibiotic spacer was constructed from a 12- to 16-hole recon plate bent to provide adequate soft tissue tension and a cement ball that matched the acetabulum. Premature failure of the plate and duration of implantation were measured. Failure was defined as fracture of the plate or dissociation of the cement head from the plate. Costs were compared with commercially available cement spacers. A total of 24 spacers were identified in 21 patients (mean age 68.9 years, mean body-mass index 26.4). The mean time between spacer placement and re-implantation was 6.4 months (range: 1.8-18 months). One patient had an indolent infection that was unresponsive to antibiotic therapy and required a hip disarticulation. At the time of reimplantation, 17 of 17 handmade spacers had no failures. Of the premade spacers, six of the seven had no failures. One premade spacer fractured at the femoral component trunion. The cost of the plate and antibiotic cement was $909-1000, approximately $5000 less than premade spacers. Antibiotic spacers can be readily constructed intraoperatively and offer good clinical outcomes with a low incidence of failure. This type of spacer saved $5000 per patient.

Robotic-Assisted and Computer-Navigated Unicompartmental Knee Arthroplasties: A Systematic Review.

INTRODUCTION: Unicompartmental knee arthroplasty (UKA) effectively improves pain and function associated with isolated compartmental knee arthritis. The developments of computer-navigated and robotic-assisted UKA are among the most significant changes that have improved patient outcomes. This study aimed to systematically review the literature to identify differences between computer-navigated and robotic-assisted UKAs. MATERIALS AND METHODS: Twenty total articles were identified. Data pertaining to demographics, outcomes, and complications/failures were extracted from each study. Reoperation/revision rates, indications for reoperation/revision, type of procedure, and number of patients who underwent conversion to TKA (when available) were recorded. RESULTS: Nine studies reported 451 computer-navigated medial UKAs, with 19 (3.9%) reportedly requiring reoperation: primary revision (n=8; 42.1%), conversion to TKA (n=6), and manipulation under anesthesia (n=5). Eleven studies reported 2,311 robotic-assisted UKAs (74 lateral UKAs), with 106 (5.0%) requiring reoperation: conversion to TKA (n=46; 43.4%), primary revision (n=43), reoperations without component-removal (n=15), subchondroplasty, and partial meniscectomy/synovectomy (both n=1). Reoperation rate discrepancy between computer-navigated and robotic-assisted UKA was not statistically significant (p=0.495); age and BMI differed between both groups (p<0.0001). DISCUSSION: This study represents the first known comparison of revision rates of computer-navigated and robotic-assisted UKA, suggesting that these methods can benefit orthopaedic surgeons, especially those new to UKA or in a low-volume practice.

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.].

Complications in Patients Undergoing Spinal Fusion After THA.

INTRODUCTION: Patients with lumbar spine and hip disorders may, during the course of their treatment, undergo spinal fusion and THA. There is disagreement among prior studies regarding whether patients who undergo THA and spinal fusion are at increased risk of THA dislocation and other hip-related complications. QUESTIONS / PURPOSES: Is short or long spinal fusion associated with an increased rate of postoperative complications in patients who underwent a prior THA? PATIENTS AND METHODS: A retrospective study of New York State's Department of Health database (SPARCS) was performed. SPARCS has a unique identification code for each patient, allowing investigators to track the patient across multiple admissions. The SPARCS dataset spans visit data of patients of all ages and races across urban and rural locations. The SPARCs dataset encompasses all facilities covered under New York State Article 28 and uses measures to further representative reporting of data concerning all races. Owing to the nature of the SPARCS dataset, we are unable to comment on data leakage, as there is no way to discern between a patient who does not subsequently seek care and a patient who seeks care outside New York State. ICD-9-Clinical Modification codes identified adult patients who underwent elective THA from 2009 to 2011. Patients who had subsequent spinal fusion (short: 2-3 levels, or long: ≥ 4 levels) with a diagnosis of adult idiopathic scoliosis or degenerative disc disease were identified. Forty-nine thousand nine hundred twenty patients met the inclusion criteria of the study. In our inclusion and exclusion criteria, there was no variation with respect to the distribution of sex and race across the three groups of interest. Patients who underwent a spinal procedure (short versus long fusion) had comparable age. However, patients who did not undergo a spinal procedure were older than patients who had short fusion (65 ± 12.4 years versus 63 ± 10.7 years; p < 0.001). Multivariate binary logistic regression models that controlled for age, sex, and Deyo/Charlson scores were used to investigate the association between spinal fusion and THA revisions, postoperative dislocation, contralateral THAs, and total surgical complications to the end of 2013. A total of 49,920 patients who had THAs were included in one of three groups (no subsequent spinal fusion: n = 49,209; short fusion: n = 478; long fusion: n = 233). RESULTS: Regression models revealed that short and long spinal fusions were associated with increased odds for hip dislocation, with associated odds ratios (ORs) of 2.2 (95% CI, 1.4-3.6; p = 0.002), and 4.4 (95% CI, 2.7-7.3; p < 0.001), respectively. Patients who underwent THA and spinal surgery also had an increased odds for THA revision, with ORs of 2.0 (95% CI, 1.4-2.8; p < 0.001) and 3.2 (95% CI, 2.1-4.8; p < 0.001) for short and long fusion, respectively. However, spinal fusions were not associated with contralateral THAs. Further, short and long spinal fusions were associated with increased surgical complication rates (OR = 2.8, 95% CI, 2.1-3.8, p < 0.001; OR = 5.3, 95% CI, 3.8-7.4, p < 0.001, respectively). CONCLUSION: We showed that spinal fusion in adults is associated with an increased frequency of complications and revisions in patients who have had a prior THA. Specifically, patients who had a long spinal fusion after THA had 340% higher odds of experiencing a hip dislocation and 220% higher odds of having to undergo a revision THA. Further research is necessary to determine whether this relationship is associated with the surgical order, or whether more patient-specific surgical goals of revision THA should be developed for patients with a spinal deformity. LEVEL OF EVIDENCE: Level III, therapeutic study.

Are Allogeneic Transfusions Decreasing in Total Knee Arthroplasty Patients? National Inpatient Sample 2009-2013.

BACKGROUND: Allogeneic transfusions are commonly used for substantial blood loss in total knee arthroplasty (TKA), but have been associated with adverse effects and increased costs. The purpose of this study is to provide a detailed description of (1) trends of allogeneic blood transfusion; (2) risk factors and adverse events; and (3) discharge disposition, length-of-stay (LOS), and cost/charge analysis for primary TKA patients who received an allogeneic blood transfusion from 2009-2013. METHODS: A cohort of 3,217,056 primary TKA patients was identified from the National Inpatient Sample database from 2009-2013. Demographic, clinical, economic, and discharge data were analyzed for patients who received allogeneic blood products, and for those who did not receive any type of blood transfusion. Other parameters analyzed include risk factors, adverse events, discharge disposition, and costs/charges. RESULTS: There was a significant decline in use of allogeneic transfusion from 2009-2013 incidence (13.9%-7.3%; P < .001). All comorbidities examined were associated with significantly increased risk of receiving allogeneic transfusion with exception of patients with AIDS, metastatic cancer, and peptic ulcer disease. Allogeneic transfusion was associated with worse outcomes during hospitalization. Patients also had a greater likelihood of discharge to short-term care, greater LOS, and greater median costs/charges. Among TKA patients who received an allogeneic transfusion, costs varied based on hospital ownership and characteristics, primary-payer, region, and bed-size. CONCLUSION: Given the poor outcomes and higher costs associated with allogeneic transfusions, efforts must be undertaken to minimize this risky practice. With the projected increase in demand for TKAs, orthopedists must understand effective blood management strategies.

Have the annual trends of total knee arthroplasty in ankylosing spondylitis patients decreased?

BACKGROUND: Ankylosing spondylitis (AS) is characterized by osteoproliferation-induced structural damage and spinal inflammation, which lead to spinal deformity and functional disability. Though AS commonly affects the axial skeleton and sacroiliac joints, up to 70% of patients have involvement of the knees and other joints. Despite pharmacological efforts, advancing joint involvement may ultimately require surgical intervention. Total knee arthroplasty (TKA) is effective in managing patients with AS, yet it remains unclear whether or not the annual rates of TKA have been affected. Therefore, the purpose of this study was to evaluate the annual trends of AS patients who underwent TKA. Specifically, we evaluated: (I) the annual trends of TKAs due to AS in the United States population; (II) the annual trends in the proportion of TKAs due to AS in the United States. METHODS: The Nationwide Inpatient Sample (NIS) was used to identify all patients who underwent TKA between 2002 and 2013 (n=6,492,873). Then, a subsequent query was performed to identify TKA patients who had a diagnosis of AS, defined by the International Classification of Disease 9th revision diagnosis code 720.0. The incidence of TKAs with a diagnosis of AS in the United States was calculated using the United States population as the denominator. Regression models were used to analyze the annual trends of AS in patients who underwent TKA. RESULTS: During the study period, 2,986 patients who had AS who underwent TKA were identified. The annual number of TKAs with a diagnosis of AS increased by 168% from 125 to 335. After normalizing to the US population, the incidence of TKAs with AS increased from 0.58 to 1.38 TKAs per million US adults [IRR =1.08 (95% CI: 1.07-1.09), P<0.001]. Out of the 350,122 TKAs in 2002, 125 (0.04%) were due to AS, whereas, out of the 640,695 TKAs in 2013, 335 (0.05%) were due to AS. The prevalence of AS in those who underwent TKA increased from 2002 to 2013 [coefficient =0.002 (95% CI: 0.001-0.003), P=0.004]. CONCLUSIONS: The annual trends of AS patients undergoing TKA significantly increased during the study period. To the authors' best knowledge, this is the first study to evaluate TKA trends in the AS population. The literature has reported on the ability of non-steroidal anti-inflammatory drugs (NSAIDs) and the potential of tumor necrosis factor-alpha (TNFα) inhibitors to hinder bone disease progression in AS, however, this was not shown to support to the significant changes found in TKA trends during the study period.

The Multiple Sclerosis Severity Score: associations with MC1R single nucleotide polymorphisms and host response to ultraviolet radiation.

BACKGROUND: Multiple sclerosis outcome may be influenced by ultraviolet radiation and vitamin D synthesis, suggesting skin type and genes determining this phenotype are candidates for disability. However, though associations between melanocortin 1 receptor (MC1R) single nucleotide polymorphisms and disability are reported, some data are incompatible with their expected influence on skin type. OBJECTIVE: Determine which MC1R single nucleotide polymorphisms affect disability and establish if ultraviolet radiation modifies such associations. METHODS: We studied using linear regression in 525 cases, associations of the Multiple Sclerosis Severity Score (MSSS) with skin type, gender, ultraviolet radiation exposure and six MC1R single nucleotide polymorphisms (rs1805005, rs1805006, rs2228479, rs1805007, rs1805008, rs1805009). RESULTS: CG(294) with GG(294) genotypes (rs1805009) (coefficient = -1.44, 95% CI -2.30, -0.59, mean MSSS +/- SD = 4.33 +/- 2.87) and AC(84) (rs1805006) (coefficient = 1.62, 95% CI 0.17, 3.06, mean MSSS = 7.62 +/- 2.43) were associated with MSSS. Associations with Asp294His were found in those with skin types 1/2 and 3/4, and cases stratified by ultraviolet radiation exposure. However, they were seen only in cases with a history of childhood sunburn and not in those without sunburn. We found no significant associations between exposure parameters and MSSS. CONCLUSIONS: Multiple sclerosis outcome is influenced by interactions between host response to ultraviolet radiation and MC1R single nucleotide polymorphisms. The influence of the single nucleotide polymorphisms appears distinct from their association with skin type.