Effects of Vancomycin/Tobramycin-Doped Ceramic Composite (Polyvinyl Alcohol Composite-Vancomycin/Tobramycin-Polymeric Dicalcium Phosphate Dihydrate) in a Rat Femur Model Implanted With Contaminated Porous Titanium Cylinders.

BACKGROUND: Periprosthetic joint infection (PJI) remains common and problematic. We hypothesized that using a bioceramic that provided rapid release of the antibiotics (vancomycin [VAN] or VAN and tobramycin [VAN and TOB]) from a polyvinyl-alcohol-composite (PVA) combined with a delayed and sustained antibiotic release from polymeric-dicalcium-phosphate-dihydrate (PDCPD) ceramic would inhibit S. aureus-associated implant infections. METHODS: A total of 50 male Sprague Dawley rats were randomly divided into 5 groups-I: negative control; II: bacteria only; III: bacteria + saline wash; IV: bacteria + PVA-VAN-PDCPD, and V: bacteria + PVA-VAN-TOB-PDCPD. A porous titanium (Ti) implant was press-fit into the rat knee. S. aureus-containing broth was added into the joint space creating a PJI. After 1 week, the joints from groups III to V were washed with saline and the fluid collected for bacterial quantification. This was followed by saline irrigation treatment (groups III to V) and application of the antibiotic-loaded PVA-PDCPD bioceramic (groups IV and V). On day 21, joint fluid was collected, and the implants harvested for bacterial quantification. RESULTS: No bacteria were isolated from the negative control (group I). The positive control (group II) was positive on both days 7 and 21. Bacteria were still present on day 21 in the fluid and implant in group III. Groups (IV and V) showed a decrease in the bacterial burden in the fluid and implant on day 21. There were significant differences in bacteria levels in the collected wash fluid and on the implant at day 21 between the saline wash (group III) and treatment groups (IV and V). CONCLUSIONS: In this animal model of acute periprosthetic infection, treatment with PVA-VAN-PDCPD and PVA-VAN/TOB-PDCPD reduced bacterial load in the infected joint and the infected Ti implant. Application of PVA-VAN-PDCPD and/or PVA-VAN/TOB-PDCPD after saline irrigation could be used as an addition to the treatment of PJI.

Cementless versus Cemented Total Knee Arthroplasty Using the Same Implant Design: A Mean 5-Year Follow-up Study.

Cementless implant use continues to increase primarily due to increased numbers of younger and obese patients opting for primary total knee arthroplasty (TKA). Given the increased use of cementless implants, the purpose of this study was to evaluate the midterm clinical performance of cementless TKA using a highly porous tibial baseplate compared with its cemented counterpart of the same system. We conducted a retrospective case-control study of 400 patients undergoing primary TKA that included 200 patients with cementless components matched for age and body mass index (BMI) to 200 patients with cemented implants of the same implant design with a 5-year follow-up. We evaluated clinical results, complications, revisions, and overall survivorship between the cohorts. Statistical analysis was performed using student t-test and chi-square analysis. There was no statistical difference in age (64.3 vs. 64.3 p = 0.81), BMI (34 vs. 33.1 p = 0.19), preoperative Knee Society Score (KSS) function (41 vs. 32.3 p = 0.22), and preoperative KSS knee score (39.2 vs. 38.3 p = 0.54) between the cementless and cemented cohorts, respectively. The cementless group had seven revisions, while the cemented group had nine revisions (p = 0.609). The cementless group had one revision due to aseptic loosening versus five in the cemented group (p = 0.09). Postoperative 5-year KSS knee scores were 92.84 versus 91.75 (p = 0.386) and function scores were 81.81 versus 69.65 (p = 0.00004) in the cementless and cemented groups, respectively. The cementless group had survivorship of 96.5% for all-cause revision compared with 95.5% in the cemented group at 5-year follow-up (p = 0.60). Cementless TKA using a highly porous tibial baseplate showed excellent midterm results with one case of aseptic loosening at 5-year follow-up and with similar Knee Society outcome scores and survivorship compared with the cemented group. Cementless TKA demonstrated noninferiority to cemented TKA and could be used as an alternative mode of fixation in patients opting for primary TKA. Additional long-term follow-up is needed to determine if cementless TKA can demonstrate improved survivorship over cemented TKA.

Untargeted metabolomic profiles reveal widespread metabolic perturbations and identify candidate biomarkers in aminoaciduric canine hypoaminoacidemic hepatopathy syndrome.

OBJECTIVE: To identify metabolites and metabolic pathways affected in dogs with aminoaciduric canine hypoaminoacidemic hepatopathy syndrome (ACHES) compared to healthy control (CON) dogs of similar ages and breeds. To improve our understanding of ACHES pathophysiology and identify novel candidate biomarkers associated with ACHES. ANIMALS: A prospective case-control study. Privately owned dogs with ACHES (n = 19) and healthy (CON) dogs (n = 9) were recruited between February 18, 2015, and April 18, 2018. METHODS: A prospective case-control study. Plasma and urine were collected from ACHES and CON dogs. The Cornell University Proteomics and Metabolomics Core Facility conducted an untargeted metabolomic analysis. RESULTS: After controlling for age, sex, and weight, 111 plasma and 207 urine metabolites significantly differed between ACHES and CON dogs. Data reduction and cluster analysis revealed robust segregation between ACHES and CON dogs. Enrichment analysis of significant compounds in plasma or urine identified altered metabolic pathways, including those related to AA metabolism, cellular energetics, and lipid metabolism. Biomarker analysis identified metabolites that best-distinguished ACHES from CON dogs, including pyruvic acid isomer and glycerol-3-phosphate in the plasma and an alanine isomer and choline in the urine. CLINICAL RELEVANCE: Our findings provide an in-depth analysis of metabolic perturbations associated with ACHES. Several affected metabolic pathways (eg, lipid metabolism) offer a new understanding of ACHES pathophysiology. Novel candidate biomarkers warrant further evaluation to determine their potential to aid in ACHES diagnosis, prognosis, and treatment monitoring.

Sinus Tarsi Versus Extended Lateral Approach for Displaced Intra-Articular Calcaneal Fractures: A Single Surgeon's Experience.

BACKGROUND: The aim of the study is to investigate the differences between the extensile lateral (EL) and sinus tarsi (ST) approaches for the treatment of displaced intra-articular calcaneus fractures as treated by a single surgeon. METHODS: A retrospective cohort study performed at a Level 1 trauma center. One hundred twenty-nine consecutive intra-articular calcaneus fractures from 2011 to 2018 that were surgically treated by a single surgeon. Primary outcomes were time to surgery, operative time, postoperative restoration of the critical angle of Gissane, postoperative wound complications, and need for unplanned re-operation. RESULTS: Patient characteristics, including demographics, mechanism of injury, and fracture patterns were similar between the EL and ST approach groups. There was a significant decrease in unplanned secondary procedures (P = .008), shorter time to definitive fixation (P = .00001), and shorter average operative time in the ST group (P = .00001). Postoperative measurement of the critical angle of Gissane between the two groups was significantly different, but minute with an average difference of approximately 3 degrees (P = .025). Measurements in both groups were within the expected range of normal. CONCLUSIONS: For displaced intra-articular calcaneus fractures, a limited open ST approach is associated with a significant reduction in the time to definitive fixation and decreased operative time. The EL approach was associated with a small, but significant improvement in the restoration of the critical angle of Gissane compared with the ST approach. Therefore, an ST approach may allow for earlier surgical intervention and result in equivalent quality of reduction compared with an EL approach. LEVEL OF EVIDENCE: Level III.

Cementless Total Knee Arthroplasty Using a Highly Porous Tibial Baseplate in Morbidly Obese Patients: Minimum 5-Year Follow-Up.

Morbidly obese patients undergoing cemented primary total knee arthroplasty (TKA) can pose a challenging problem with implant survivorship due to greater stress at the cement-bone interface. With the advent of additive manufacturing (three-dimensional printing), highly porous implants are now readily available. The purpose of this study was to review the results of primary TKA in the morbidly obese (body mass index [BMI] ≥ 40) patient using a highly porous cementless tibial baseplate. This is a retrospective study of 167 TKAs in patients with morbid obesity undergoing primary cementless TKA with a minimum 5-year follow-up. A total of 6 patients died and 14 were lost to follow-up, leaving 147 TKAs in 136 patients with a mean follow-up of 66 months (range 60-79 months). The average age was 59 years (range 36-84 years) and average BMI was 45 kg/m2 (range 39.5-63.9). Clinical results, patient-reported outcome measures, radiographs, and complications were reviewed. There were 9 failures requiring revision, including 3 for aseptic tibial loosening (2.0%), 2 for deep infection (1.4%), 2 for patellar resurfacing (1.4%), 1 for patella instability (0.7%), and 1 for extensor mechanism rupture (0.7%). Knee Society Score (KSS) improved from 48 to 90 at 2- and 5-year follow-up. KSS function score improved from 49 to 68 and 79 at 2- and 5-year follow-up, respectively. Survivorship with aseptic loosening as the endpoint was 98.0% at 5 years. Cementless TKA using a highly porous tibial baseplate in morbidly obese patients demonstrated excellent clinical results with 98% survivorship at 5 years and appears to offer durable long-term biologic fixation as an alternative to mechanical cement fixation in this challenging group of patients.

Clinical features and amino acid profiles of dogs with hepatocutaneous syndrome or hepatocutaneous-associated hepatopathy.

BACKGROUND: Superficial necrolytic dermatitis (SND), hepatocutaneous-associated hepatopathy (HCH), aminoaciduria, and hypoaminoacidemia define hepatocutaneous syndrome (HCS) in dogs. Dogs without SND but that possess all other syndrome components are not well described. HYPOTHESIS/OBJECTIVES: To define an inclusive syndrome, aminoaciduric canine hypoaminoacidemic hepatopathy syndrome (ACHES) for dogs with HCH or HCS. Compare clinical features, salient clinicopathologic variables, and plasma and urine amino acid (AA) profiles among ACHES cases by skin lesion status. ANIMALS: Dogs of various breeds and ages diagnosed with ACHES (n = 41). A control (CON) cohort (n = 12) provided AA profile data. METHODS: Retrospective case series. Available medical records of previously identified cases were reviewed for salient clinical features and clinical pathology data. Plasma and urine AA profiles were performed. Cutaneous lesion status was classified as none, mild, or fulminant. RESULTS: Thirty cases (73%) developed SND at some time. Dogs with fulminant skin lesions at diagnosis (n = 22/41, 54%) had significantly lower hematocrit (P = .05) and mean corpuscular volume (P = .01) than dogs without SND. Principal component analysis of plasma AA profiles identified distinct clustering of CON from ACHES dogs, but not by skin lesion status. Plasma 1-methylhistidine (<7 nmol/mL) and cystathionine (<7.5 nmol/mL) were robust ACHES biomarkers. Urine lysine (>344 nmol/mg creatinine) and methionine (>68 nmol/mg creatinine) also were useful ACHES biomarkers. CONCLUSIONS AND CLINICAL IMPORTANCE: Specific AA biomarkers provide additional diagnostic utility in ACHES. Data suggests that HCH is an early stage, and SND a later stage manifestation of ACHES.

Treatment and outcomes of dogs with hepatocutaneous syndrome or hepatocutaneous-associated hepatopathy.

BACKGROUND: Superficial necrolytic dermatitis (SND) in dogs is a rare disorder most commonly associated with hepatocutaneous syndrome. Although often reported as fatal, sporadically reported long-term remissions might be more common than previously believed and linked to treatment regimens. HYPOTHESIS/OBJECTIVES: Evaluate treatments and associated outcomes in dogs with hepatocutaneous-associated hepatopathy (HCH) with or without SND, designated collectively aminoaciduric canine hypoaminoacidemic hepatopathy syndrome (ACHES). ANIMALS: Forty-one dogs of various breeds and ages diagnosed with ACHES. METHODS: Retrospective study. Electronic surveys, medical records (2014-2019), and communication with veterinarians provided data. Three treatment categories were each dichotomized: IV amino acid (IV-AA) infusions (≥2 vs <2), supplements including S-adenosylmethionine (SAMe), arginine with ornithine, glutathione, lysine, proline, omega-3 fatty acids, or zinc (≥3 vs <3), and diet type (home-cooked vs commercial). Optimal treatment was defined as receiving ≥2 IV-AA treatments, ≥3 nutritional supplements, and a home-cooked diet. RESULTS: Most dogs (29/41, 71%) received IV-AA infusions (23/29, ≥2 infusions). Twenty-one dogs (51%) were fed commercial diets; 17/41 (41%) were fed home-cooked diets. Most dogs received SAMe (32/41, 78%) and a median of 3 supplements. In 4 dogs, HCH remission occurred. Overall all-cause median survival time (MST) was 359 days, and disease-specific MST was 557 days (range, 1-1783 days). Optimally treated dogs (n = 9) lived significantly longer (MST, >1783 days, P = .02) than variably treated dogs (MST, 214 days). CONCLUSIONS AND CLINICAL IMPORTANCE: Optimized ACHES management can resolve SND and HCH and confer long-term survival.

Disparities in hepatic copper concentrations determined by atomic absorption spectroscopy, inductively coupled plasma mass spectrometry, and digital image analysis of rhodanine-stained sections in dogs.

OBJECTIVE: To investigate disparities in hepatic copper concentrations determined by atomic absorption spectroscopy (AAS), inductively coupled plasma mass spectrometry (ICP-MS), and digital image analysis of rhodanine-stained sections. ANIMALS: 516 dogs. PROCEDURES: Medical records of dogs for which hepatic biopsy specimens had been submitted between January 1999 and December 2019 for evaluation of copper content were reviewed. Paired hepatic copper concentrations obtained with digital image analysis and AAS or ICP-MS were compared, and Spearman rank correlation coefficients were calculated to test for correlations between qualitative copper accumulation scores and hepatic copper concentrations. For dogs for which ≥ 4 rhodanine-stained hepatic sections were available, intraindividual variation in copper distribution across hepatic sections was evaluated. RESULTS: Median hepatic copper concentrations obtained with digital image analysis exceeded concentrations obtained with AAS or ICP-MS. Concentrations were also higher in older dogs (≥ 9 years vs < 9 years), dogs of breeds with a typical body weight ≥ 20 kg (44 lb), and dogs with necroinflammatory changes or uneven copper distribution. Qualitative copper accumulation scores were significantly associated with hepatic copper concentrations; however, the correlation between qualitative score and concentration obtained with digital image analysis (rs = 0.94) was higher than the correlation between qualitative score and concentration obtained with AAS (rs = 0.75) or ICP-MS (rs = 0.57). The coefficient of variation for hepatic copper concentrations obtained with digital image analysis was significantly higher for dogs with higher hepatic copper concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that spectroscopic-spectrometric analysis of hepatic biopsy specimens commonly underestimated the concentration obtained by digital image analysis of rhodanine-stained sections.

A Geographic Population-level Analysis of Access to Total Shoulder Arthroplasty in the State of Texas.

INTRODUCTION: Managing costs and improving access to care are two important goals of healthcare policy. The purposes of this study were to (1) evaluate the changes in distribution of total shoulder arthroplasty (TSA) cases in the state of Texas from 2010 to 2015 and (2) to evaluate patient access to TSA surgery centers as measured by driving miles. METHODS: Inpatient (IP) and outpatient (OP) records were obtained from 2010 to 2015 from the Texas Department of State Health Services. All primary elective anatomic or reverse TSAs for patients with Texas-based home residence zip codes were included. Driving miles between patient zip codes and their chosen TSA surgery centers were estimated, and the results were compared between IP (high-volume [HV-IP] or low-volume [LV-IP]) and OP centers. Paired student t-tests, multivariate regressions, and mixed-model analysis of variance (ANOVA) were performed for volume comparisons, interactions between TSA centers types, and yearly trend data, respectively. RESULTS: Between 2010 and 2015, a total of 21,092 TSA procedures were performed across 321 surgery centers in the state of Texas (19,629 IP [93.1%] and 1,463 OP [6.9%]). During this time, the cumulative volume of IP TSA per 100,000 Texas residents increased by 109.1%, whereas the cumulative volume of OP TSA increased by 143.7%. Approximately 85.5% of included patients resided within 50 miles of any TSA surgery center; however, only 47.0% of the total Texas population resided within 50 miles of any TSA surgery center. This relationship remained true at every time point irrespective of their volume designations (OP, IP, HV-IP, and LV-IP). CONCLUSION: Despite the overall increase in TSA volume over time, the majority all TSA utilization in the state of Texas occurred in patients who resided within 50 miles of a TSA center. Increasing volume seems to reflect concentration of care into HV-IP and OP centers. Strategies to improve access to TSA care for underserved areas should be considered. LEVEL OF EVIDENCE: Level II.

Impact of early mobilization on length of stay after primary total knee arthroplasty.

BACKGROUND: Decreasing length of stay (LOS) following primary total knee arthroplasty (TKA) has been an important focus by all the stakeholders involved in the delivery of care. LOS is dictated by both the patient and hospital-related factors. The purpose of this study was to determine if early mobilization on post-operative day 0 (POD 0) following primary TKA has an effect on hospital LOS and discharge to home vs. rehabilitation facilities. METHODS: An analysis was performed of consecutive primary TKAs performed at a single institution over one year. Patients were assigned to two groups: POD 0 or POD 1, based on their day of mobilization. Patients were mobilized following surgery based on time of arrival to the orthopaedic floor and availability of physical therapy (PT) resources. The two groups were compared for LOS and discharge disposition using univariate analysis. A total of 408 consecutive TKAs were evaluated and from this group, a total of 143 patients who were mobilized on POD 0 were then matched to 143 patients mobilized on POD 1. There were no significant differences in age, sex, American Society of Anesthesiologists score, or body mass index (BMI) between POD 0 and POD 1 groups. RESULTS: There was a significant difference in LOS between POD 0 and POD 1 groups, 2.44 vs. 2.80 days (P=0.002). There were also differences in discharge to home vs. rehabilitation, 70.63% of the POD 0 cohort were discharged home compared to 58.74% in POD 1 (P=0.035). CONCLUSIONS: There was a significant reduction in LOS and there were differences in discharge disposition between patients who mobilized on POD 0 vs. POD 1, with more patients mobilized on POD 0 discharged home. Hospitals should work with their total joint arthroplasty programs to mobilize close to 100% of the patients undergoing primary TKA on POD 0 in order to decrease LOS and healthcare expenditure.

Results of Cemented vs Cementless Primary Total Knee Arthroplasty Using the Same Implant Design.

BACKGROUND: Although cemented total knee arthroplasty (TKA) continues to be the gold standard, there are patient populations with higher failure rates with cemented TKAs such as the obese, morbidly obese, and younger active males. Cementless TKA usage continues to increase because of the potential benefits of long-term biologic fixation similar to the rise in cementless total hip arthroplasty. The purpose of this study was to evaluate the clinical and radiographic results of cementless TKA using a novel highly porous cementless tibial baseplate. METHODS: This was a retrospective matched case-control study of 400 primary TKAs comparing cementless vs cemented TKAs using the same implant design (Stryker Triathlon; Stryker Inc, Mahwah, NJ). Two-hundred patients with a mean age of 64 years (range 42-88 years) and body mass index (BMI) of 33.9 kg/m2 (range 19.7-57.1 kg/m2) were matched to 200 primary cemented TKA patients with a mean age of 64 years (range 43-87 years) and BMI of 33.1 kg/m2 (range 22.2-53.2 kg/m2). The mean follow-up in the cementless group was 2.4 years (range 2-3.5 years) and in the cemented group was 5.3 years (range 2-10.9 years). Clinical and radiographic analyses were evaluated. Statistical analysis was performed using the Microsoft Excel, version 15.21.1. RESULTS: There was no statistical difference in age, BMI, and preoperative Knee Society Scores between the 2 groups (P = .22, P = .82, and P = .43, respectively). Patients in both groups had a similar incidence of postoperative complications (P = .90). Cementless group had 7 revisions with one aseptic loosening of the tibial component (0.5%). Cementless tibial baseplates demonstrated areas of increased bone density at the pegs of the tibial baseplate. The cemented group had 8 total revisions with 5 cases of aseptic loosening (2.5%). CONCLUSION: Early results of cementless TKA using a highly porous tibial baseplate designed with a keel and 4 pegs appear promising with one case of aseptic loosening at minimum 2-year follow-up. As the demographics of patients undergoing TKA change to include younger, obese, and more active patients, along with increased life expectancy, the use of a highly porous cementless tibial baseplate may be beneficial in providing long-term durable biologic fixation similar to the success of cementless total hip arthroplasty.