Comparing Unicompartmental Knee Arthroplasty and High Tibial Osteotomy for Isolated Medial Compartment Knee Osteoarthritis.

¼: Both unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) allow for compartment-specific intervention on an arthritic knee joint that preserves bone stock and native soft tissue compared to a total knee arthroplasty (TKA). Both operations give a more natural feeling with native proprioception compared with a TKA. ¼: HTO is better suited in patients who are younger (<55 years-of-age), have a body mass index (BMI) <30 kg/m2, high activity requirements, mechanical malalignment, asymmetric varus, isolated anterior cruciate ligament insufficiency, need for multiplanar correction, and a preference for joint preserving interventions. Recent data suggest that age (>55 years-of-age) should not solely contraindicate a HTO. ¼: UKA may be chosen in patients who are older (>55 years-of-age), low activity requirements, have a BMI <40 kg/m2, severe osteoarthritis with significant joint space narrowing, acceptable coronal alignment, symmetric varus, and patient preference for arthroplasty.

Computer Navigation vs. Conventional Overlay Methods in Direct Anterior Total Hip Arthroplasty: A Single Surgeon Experience.

BACKGROUND:  The use of computer navigation (CN) is expanding in direct anterior (DA) total hip arthroplasty (THA). In this study, we investigated the use of a noninvasive, fluoroscopic-based, CN technology suite on operative outcomes in a single surgeon DA THA practice. HYPOTHESIS: Computer-navigated DA THA decreases leg length discrepancy (LLD) variation and fluoroscopic radiation dose without adding operative time compared to the traditional overlay (OL) technique. METHODS: A retrospective review was performed on a total of 109 primary DA THA patients, with 58 in the CN and 51 in the OL group. Outcome metrics were postoperative LLD, radiation dose per case, and operative time. Statistical analysis was completed with Mann-Whitney U tests for differences between the means for LLD, radiation dose, and operative time. RESULTS: No difference was observed in postoperative LLD between the CN (average: 1.8 mm) and OL (average: 1.9 mm) groups (p = 0.458). A significant reduction in average radiation dose (mGy) per case within the CN group (8.17 ± 6.09 mGy) compared to the OL group (13.17 ± 7.75 mGy) (p < 0.02) was observed. The average operative time in the CN group was 80 ± 18 minutes compared to 120 ± 32 minutes in the OL group (p < 0.01). CONCLUSION: There was no difference in LLD between the two groups. The addition of CN into a DA THA practice decreased both average radiation dose and operative time when compared to the standard OL technique.

A Novel Radiographic Finding of Intracapsular Heterotopic Ossification: A Report of Two Cases.

Symptomatic heterotopic ossification (HO) is a complication of hip arthroscopy that occurs in less than 1% of cases. To our knowledge, there are no reported cases of symptomatic intracapsular HO. We present 2 patients with a radiographic finding associated with intracapsular HO. Both patients underwent revision hip arthroscopy and required capsular reconstruction due to void of the iliofemoral ligament following excision of HO. We believe this radiographic finding may be useful to hip preservationists as it may be associated with capsular deficiency necessitating capsular reconstruction upon revision hip arthroscopy.

Predictive Modeling for Geriatric Hip Fracture Patients: Early Surgery and Delirium Have the Largest Influence on Length of Stay.

BACKGROUND: Averaging length of stay (LOS) ignores patient complexity and is a poor metric for quality control in geriatric hip fracture programs. We developed a predictive model of LOS that compares patient complexity to the logistic effects of our institution's hip fracture care pathway. METHODS: A retrospective analysis was performed on patients enrolled into a hip fracture co-management pathway at an academic level I trauma center from 2014 to 2015. Patient complexity was approximated using the Charlson Comorbidity Index and ASA score. A predictive model of LOS was developed from patient-specific and system-specific variables using a multivariate linear regression analysis; it was tested against a sample of patients from 2016. RESULTS: LOS averaged 5.95 days. Avoidance of delirium and reduced time to surgery were found to be notable predictors of reduced LOS. The Charlson Comorbidity Index was not a strong predictor of LOS, but the ASA score was. Our predictive LOS model worked well for 63% of patients from the 2016 group; for those it did not work well for, 80% had postoperative complications. DISCUSSION: Predictive LOS modeling accounting for patient complexity was effective for identifying (1) reasons for outliers to the expected LOS and (2) effective measures to target for improving our hip fracture program. LEVEL OF EVIDENCE: III.

CT-measurement predicts shortening of stable intertrochanteric hip fractures.

PURPOSE: Intertrochanteric (IT) hip fractures can be treated with sliding hip screws (SHS) or cephalomedullary nails (CMN) based on the stability of the fracture. This stability is affected by the initial impaction of the fracture which can be difficult to assess. The aim of this paper is to develop specific pre-operative computed tomography (CT) measurements of IT fractures which are predictive of post-operative shortening. METHODS: A retrospective review was performed of 141 patients with AO/OTA 31A1 or 31A2 fracture patterns, who had pre-operative radiographs and CT scans, and who were treated with a SHS or a CMN. Pre-operative and post-operative imaging of IT fractures were analyzed for those fractures that shortened ≥15 mm post-fixation. RESULTS: 11 fractures shortened ≥15 mm with CMN being protective of shortening (6/36 SHS versus 5/105 CMN, p = 0.0268). A novel measurement made on the pre-operative CT scan called the cortical thin point (CTP) detected differences between patients with <15 mm and ≥15 mm of post-operative shortening for the SHS group (p = 0.0375). CTP was found to be a reliable predictor for post-operative shortening of ≥15 mm when a cutoff threshold of 9 mm was used in the SHS group (p = 0.0161). CONCLUSIONS: Measuring the CTP is predictive of post-operative shortening after fixation of an IT fracture with a SHS. CMN fixation may be protective of shortening. Patients with a CTP of ≤9 mm are at risk for fracture site shortening of more than 15 mm when treated with a SHS.

Functional Assessment of Children and Adolescents with Symbrachydactyly: A Unilateral Hand Malformation.

BACKGROUND: We studied children and adolescents with symbrachydactyly to determine whether hand function depends on digit opposability and whether scores for function and quality-of-life measures differ from population norms. METHODS: Participants were grouped on the basis of hand morphology: Group A lacked opposable digits, and Group B had ≥2 digits that were opposable. The groups were compared with each other and with norms with respect to pinch strength, the performance of bimanual activities and in-hand manipulation, and questionnaires regarding psychosocial status and the ability to perform activities of daily living (ADLs). Participants and parents also rated the appearance and function of the hand. RESULTS: Pinch strength was higher for participants in Group B (4.1 compared with 2.4 kg; p = 0.008), but the groups did not differ with respect to the proportion of participants outside of pinch norms. Participants in Group B were more likely to actively use their affected hand to perform bimanual activities (p ≤ 0.0009), and to use normal or supination strategies to accomplish in-hand manipulation (p = 0.031). The groups did not differ in the proportion of ADLs rated "difficult" or "impossible," and both groups tested within normal limits for psychosocial function. Participants from both groups and their parents rated their satisfaction with hand appearance and function similarly high. CONCLUSIONS: Participants with ≥2 opposable digits incorporated their hand better in bimanual activities and used more effective strategies to accomplish in-hand manipulation than those who did not. These groups reported no difference in the ability to perform ADLs or with psychosocial function, which was within the normal range. Children and adolescents with symbrachydactyly demonstrated and reported a high level of function in all domains of validated function tests. This study provides information to help parents of children with a unilateral hand malformation understand their child's potential function, and assist surgeons with recommending treatment. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

When are CT angiograms indicated for patients with lower extremity fractures? A review of 275 extremities.

BACKGROUND: Computed tomography angiogram (CTA) is frequently utilized to detect vascular injuries even without examination findings indicating a vascular injury. We had the following hypotheses: (1) a CTA for lower extremity fractures with no clinical signs of a vascular injury is not indicated, and (2) fracture location and pattern would correlate with the risk of a vascular injury. METHODS: A retrospective review was conducted on patients who had an acute lower extremity fracture(s) and a CTA. Their charts were reviewed for multiple factors including the presence or absence of hard or soft signs of a vascular injury, soft tissue status, and fracture location/pattern. Every CTA radiology report was reviewed and any vascular intervention or amputation resulting from a vascular injury was recorded. Statistical analysis was performed. RESULTS: Of the 275 CTAs of fractured extremities reviewed, 80 (29%) had a positive CTA finding and 16 (6%) required treatment. A total of 109 (40%) of the extremities had no hard or soft signs; all had normal CTAs. Having at least one hard or soft sign was a significant risk factor for having a positive CTA. An open fracture, isolated proximal third fibula fracture, distal and shaft tibia fractures, and the presence of multiple fractures in one extremity were also associated with an increased risk for having a positive CTA. CONCLUSION: We found no evidence to support the routine use of CTAs to evaluate lower extremity fractures unless at least one hard or soft sign is present. The presence of an open fracture, distal tibia or tibial shaft fractures, multiple fractures in one extremity, and/or an isolated proximal third fibula fracture increases the risk of having a finding consistent with a vascular injury on a CTA. Only 6% of the cases required treatment, and all of them had diminished or absent distal pulses on presentation. LEVEL OF EVIDENCE: Diagnostic test, level III.

Symbrachydactyly.

Background: Symbrachydactyly is a unilateral congenital hand malformation characterized by failure of formation of fingers and the presence of rudimentary digit nubbins. The management is variable and are investigated in this review. Methods: A detailed review of the literature was compiled into succinct clinically relevant categories. Results: Etiology, classification, non-surgical management, surgical intervention, and patient oriented outcomes are discussed. Conclusions: All interventions should prioritize realistic, evidence-supported appearance and functional gains. Studies of the baseline function and quality of life of children with symbrachydactyly would allow surgeons to better understand functional changes associated with various interventions and would help surgeons and parents to make the best treatment decisions.

Problematic Pediatric Hand and Wrist Fractures.

Seymour fractures are open juxta-physeal fractures of the distal phalanx. A true lateral radiograph should be obtained for diagnosis, and treatment should include removal of the nail, irrigation and debridement of the fracture, and percutaneous Kirschner wire stabilization. Mallet fractures are more common in children than adults, and treatment is generally nonoperative for nondisplaced or minimally displaced fractures without volar subluxation of the distal phalanx; however, splinting compliance should be carefully assessed in younger populations. Phalangeal neck fractures have a limited potential to remodel and a propensity to redisplace. A true lateral radiograph will show displacement best; treatment is generally with percutaneous pinning. Open reduction should be avoided when possible because of the risk of osteonecrosis of the phalangeal condyles. The epidemiology of scaphoid fractures in children is changing, with waist fractures now the most common type. This may be due to an increase in body mass index (BMI) as well as high-level sports participation in today's pediatric population. Although the vast majority of acute scaphoid fractures can be treated successfully with cast immobilization, children who present with established nonunions should be offered open reduction and internal fixation as the primary treatment.

Overdiagnosis of Clostridium difficile Infection in the Molecular Test Era.

IMPORTANCE: Clostridium difficile is a major cause of health care-associated infection, but disagreement between diagnostic tests is an ongoing barrier to clinical decision making and public health reporting. Molecular tests are increasingly used to diagnose C difficile infection (CDI), but many molecular test-positive patients lack toxins that historically defined disease, making it unclear if they need treatment. OBJECTIVE: To determine the natural history and need for treatment of patients who are toxin immunoassay negative and polymerase chain reaction (PCR) positive (Tox-/PCR+) for CDI. DESIGN, SETTING, AND PARTICIPANTS: Prospective observational cohort study at a single academic medical center among 1416 hospitalized adults tested for C difficile toxins 72 hours or longer after admission between December 1, 2010, and October 20, 2012. The analysis was conducted in stages with revisions from April 27, 2013, to January 13, 2015. MAIN OUTCOMES AND MEASURES: Patients undergoing C difficile testing were grouped by US Food and Drug Administration-approved toxin and PCR tests as Tox+/PCR+, Tox-/PCR+, or Tox-/PCR-. Toxin results were reported clinically. Polymerase chain reaction results were not reported. The main study outcomes were duration of diarrhea during up to 14 days of treatment, rate of CDI-related complications (ie, colectomy, megacolon, or intensive care unit care) and CDI-related death within 30 days. RESULTS: Twenty-one percent (293 of 1416) of hospitalized adults tested for C difficile were positive by PCR, but 44.7% (131 of 293) had toxins detected by the clinical toxin test. At baseline, Tox-/PCR+ patients had lower C difficile bacterial load and less antibiotic exposure, fecal inflammation, and diarrhea than Tox+/PCR+ patients (P < .001 for all). The median duration of diarrhea was shorter in Tox-/PCR+ patients (2 days; interquartile range, 1-4 days) than in Tox+/PCR+ patients (3 days; interquartile range, 1-6 days) (P = .003) and was similar to that in Tox-/PCR- patients (2 days; interquartile range, 1-3 days), despite minimal empirical treatment of Tox-/PCR+ patients. No CDI-related complications occurred in Tox-/PCR+ patients vs 10 complications in Tox+/PCR+ patients (0% vs 7.6%, P < .001). One Tox-/PCR+ patient had recurrent CDI as a contributing factor to death within 30 days vs 11 CDI-related deaths in Tox+/PCR+ patients (0.6% vs 8.4%, P = .001). CONCLUSIONS AND RELEVANCE: Among hospitalized adults with suspected CDI, virtually all CDI-related complications and deaths occurred in patients with positive toxin immunoassay test results. Patients with a positive molecular test result and a negative toxin immunoassay test result had outcomes that were comparable to patients without C difficile by either method. Exclusive reliance on molecular tests for CDI diagnosis without tests for toxins or host response is likely to result in overdiagnosis, overtreatment, and increased health care costs.

An analysis of two island groups as potential sites for trials of transgenic mosquitoes for malaria control.

Considerable technological advances have been made towards the generation of genetically modified mosquitoes for vector control. In contrast, less progress has been made towards field evaluations of transformed mosquitoes which are critical for evaluating the success of, and hazards associated with, genetic modification. Oceanic islands have been highlighted as potentially the best locations for such trials. However, population genetic studies are necessary to verify isolation. Here, we used a panel of genetic markers to assess for evidence of genetic isolation of two oceanic island populations of the African malaria vector, Anopheles gambiae s.s. We found no evidence of isolation between the Bijagós archipelago and mainland Guinea-Bissau, despite separation by distances beyond the known dispersal capabilities of this taxon. Conversely, the Comoros Islands appear to be genetically isolated from the East African mainland, and thus represent a location worthy of further investigation for field trials. Based on assessments of gene flow within and between the Comoros islands, the island of Grande Comore was found to be genetically isolated from adjacent islands and also exhibited local population structure, indicating that it may be the most suitable site for trials with existing genetic modification technologies.

High degree of single nucleotide polymorphisms in California Culex pipiens (Diptera: Culicidae) sensu lato.

Resolution of systematic relationships among members of the Culex pipiens (L.) complex has important implications for public health as well as for studies on the evolution of sibling species. Currently held views contend that in California considerable genetic introgression occurs between Cx. pipiens and Cx. quinquefasciatus Say, and as such, these taxa behave as if they are a single species. Development of high throughput SNP genotyping tools for the analysis of Cx. pipiens complex population structure is therefore desirable. As a first step toward this goal, we sequenced 12 gene fragments from specimens collected in Marin and Fresno counties. On average, we found a higher single nucleotide polymorphism (SNP) density than any other mosquito species reported thus far. Coding regions contained significantly higher GC content (median 54.7%) than noncoding regions (42.4%; Wilcoxon rank sum test, P = 5.29 x 10(-5)). Differences in SNP allele frequencies observed between mosquitoes from Marin and Fresno counties indicated significant genetic divergence and suggest that SNP markers will be useful for future detailed population genetic studies of this group. The high density of SNPs highlights the difficulty in identifying species within the complex and may be associated with the large degree of phenotypic variation observed in this group of mosquitoes.