Pediatric Ulnar-sided Wrist Pain: A Review of the Current Literature.

Patients presenting with ulnar-sided wrist pain can pose a diagnostic and therapeutic challenge to physicians because there are several pathologies with similar signs and symptoms. In comparison with adult patients, other etiologies must be considered in the pediatric patient, given the skeletal immaturity and potential for known or unrecognized syndromes. In addition, these patients may not be able to articulate their symptoms as clearly as an adult patient, further stressing the importance of obtaining a pertinent history and performing a focused physical examination. Having a thorough understanding of the anatomy, the varying pathologies, and the indications for surgical and nonsurgical management will assist in improved patient outcomes.

A matched quantitative computed tomography analysis of 3 surgical approaches for osteochondral reconstruction of the capitellum.

BACKGROUND: The location of capitellar osteochondritis dissecans (OCD) lesions in the sagittal plane guides the surgical approach used for autologous osteochondral transplantation. We sought to compare the capitellar region accessible for orthogonal graft placement through 3 approaches: (1) posterior anconeus-split approach; (2) lateral approach with lateral collateral ligament (LCL) preservation (LCL-preserving lateral approach); and (3) lateral approach with LCL release (LCL-sacrificing lateral approach). METHODS: The 3 approaches were sequentially performed on 9 cadaveric elbows: posterior anconeus-split approach, LCL-preserving lateral approach, and LCL-releasing lateral approach. The extent of perpendicular access was delineated with Kirschner wires. Each specimen underwent computed tomography. The accessible region was quantified as degrees on the capitellum and converted into time on a clock, where 0° corresponds to the 12-o'clock position. Generalized estimating equation modeling was used to investigate for significant within-specimen, between-approach differences. RESULTS: The LCL-preserving and LCL-sacrificing lateral approaches provided more anterior perpendicular access than the posterior anconeus-split approach (mean, 0° vs 83°; P < .001). The posterior anconeus-split approach provided more posterior perpendicular access (mean, 215.0°; P < .001) than the LCL-preserving (mean, 117°; P < .001) and LCL-sacrificing (mean, 145°; P < .001) lateral approaches. The LCL-sacrificing lateral approach provided more posterior exposure than the LCL-preserving lateral approach (mean, 145° vs 117°; P < .001). The mean arc of visualization was greater for the LCL-sacrificing lateral approach than for the LCL-preserving lateral approach (145° vs 117°, P < .001). CONCLUSIONS: A capitellar OCD lesion can be perpendicularly accessed from a posterior anconeus-split approach if it is posterior to 83° (2:46 clock-face position). A laterally based approach may be required for lesions anterior to this threshold. These data inform clinical decisions regarding the appropriate surgical approach for any OCD lesion.

Distal Radius Fractures: Reconstruction Approaches, Planning, and Principles.

Distal radius fracture (DRF) is a common injury. Treatment options have evolved and now several can be used to address even the most complex fracture patterns. Complex fractures of the distal radius and ulna can be challenging, and specific goals must be kept in mind to achieve definitive anatomical and functional restoration. This article summarizes the concepts, principles, and surgical options regarding complex DRF reconstruction.

Failure after reverse total shoulder arthroplasty: what is the success of component revision?

BACKGROUND: Complication rates remain high after reverse total shoulder arthroplasty (RTSA). Salvage options after implant failure have not been well defined. This study examines the role of reimplantation and revision RTSA after failed RTSA, reporting outcomes and complications of this salvage technique. METHODS: Sixteen patients underwent component revision and reimplantation after a prior failed RTSA from 2004 to 2011. Indications included baseplate failure (7 patients, 43.8%), instability (6 patients, 37.5%), infection (2 patients, 12.5%), and humeral loosening (1 patient, 6.3%). The average age of the patient during revision surgery was 68.6 years. Outcomes information at follow-up was recorded, including visual analog scale score for pain, subjective shoulder value, American Shoulder and Elbow Surgeons score, and Simple Shoulder Test score, and these were compared with pre-revision values. Repeated surgeries and complications were noted. RESULTS: Average time to follow-up from revision was 58.9 months (minimum, 2 years; range, 24-103 months). The average postoperative visual analog scale score for pain was 1.7/10 (7.5/10 preoperatively; P < .0001), and the subjective shoulder value was 62% (17% preoperatively; P < .0001). The average postoperative American Shoulder and Elbow Surgeons score was 66.7, and the Simple Shoulder Test score was 52.6. Fourteen patients (88%) noted that they felt "better" postoperatively than before their original RTSA and would go through the procedure again if given the option. Nine patients suffered major complications (56%), and 6 of these ultimately underwent further procedures (38% of cohort). DISCUSSION: Salvage options after failure of RTSA remain limited. Component revision and reimplantation can effectively relieve pain and improve function compared with baseline values, and patient satisfaction levels are moderately high. However, complication rates and reoperation rates are significant.

Reverse shoulder arthroplasty as salvage for failed prior arthroplasty in patients 65 years of age or younger.

BACKGROUND: This study examined outcomes and complications in young patients undergoing revision reverse total shoulder arthroplasty (RTSA) for failed prior total shoulder arthroplasty or hemiarthroplasty and compared them with those of an age-matched cohort undergoing primary RTSA. METHODS: RTSA as a revision for failed shoulder arthroplasty was performed on 36 patients younger than 65 years. Follow-up was available for 32 patients at an average of 55.3 months. Results were compared with those of an age-matched cohort of 37 patients (33 available for follow-up; average, 54.7 months) undergoing primary RTSA. Average age for both groups was 59.3 years. Outcomes were compared before and after revision surgery and between cohorts. RESULTS: Preoperative visual analog scale (VAS) for pain and subjective shoulder value (SSV) scores were similar in both groups, 7.3 of 10 and 24%, respectively, before revision, and 7.0 of 10 and 19% before primary RTSA (P = .3). Postrevision VAS and SSV scores improved to 1.4 of 10 and 60% (P < .0001). Average American Shoulder and Elbow Surgeons and Simple Shoulder Test scores after revision were 69.7 and 58.8, with 9 complications (28.1%; 6 major and 3 minor). VAS and SSV scores improved to 2.1 of 10 and 76% after primary RTSA (P < .0001). American Shoulder and Elbow Surgeons and Simple Shoulder Test scores after primary RTSA were 74 and 67.3, with 6 complications (18.2%; 5 major and 1 minor). Only the postoperative SSV score was statistically different in comparing primary and revision RTSA (P < .05). CONCLUSION: RTSA is effective in reducing pain and improving function after failed arthroplasty in young patients, but complication rates are high and expectations should be managed appropriately. Subjective outcome scores are worse than those for age-matched patients undergoing primary RTSA, but pain, functional scores, and complication rates are similar.

Resident education in the systems-based practice competency.

More than 10 years after the establishment of the six core competencies by the Accreditation Council for Graduate Medical Education, systems-based practice remains an elusive subject to teach, measure, and document. A wide variety of methods have been reported that address teaching and assessing performance for the discrete parts of systems-based practice; however, no single approach has been described that encompasses the competency in its entirety. To better understand the current state of this competency, orthopaedic residents and educators from around the country were surveyed to determine which systems-based practice topics were being taught at their institutions, how these topics were being taught, and how resident performance was assessed. Seven focus group sessions were held with members involved in the care of musculoskeletal patients to determine what they believed were essential skills for residents to learn relative to the healthcare system. Using this information, a health systems rotation was created for first-year residents that incorporated several different teaching and assessment methods. This rotation has received positive feedback from residents, patients, and health professionals. Its effect on resident development will be tracked over the next 5 years.

Reshaping orthopaedic resident education in systems-based practice.

BACKGROUND: Despite advances in understanding the "systems-based practice" competency in resident education, this topic has remained difficult to teach, assess, and document. The goal of this study was to perform a needs assessment and an analysis of the current state of systems-based practice education in orthopaedic residency programs across the U.S. and within our own institution. METHODS: A sample of orthopaedic educators and residents from across the U.S. who were attending the 2010 American Orthopaedic Association (AOA) Effective Orthopaedic Educator Course, AOA Resident Leadership Forum, and AOA Council of Residency Directors meeting were surveyed to determine (1) which aspects of systems-based practice, if any, were being taught; (2) how systems-based practice is being taught; and (3) how residency programs are assessing systems-based practice. In addition, an in-depth case study of these issues was performed by means of seven semi-structured focus group sessions with diverse stakeholders who participated in the care of musculoskeletal patients at the authors' institution. A quantitative approach was used to analyze the survey data. The focus group data were analyzed with procedures associated with grounded theory, relying on a constant comparative method to develop salient themes arising from the discussion. RESULTS: "Clinical observation" (33%) and "didactic case-based learning" (23%) were reported by the survey respondents as the most commonly used teaching methods, but specific topics were taught inconsistently. Competency assessment was reported to occur infrequently, and 36% of respondents reported that systems-based practice areas were not being assessed by any methods. The focus group discussions emphasized the need for standardized experiential learning that was closely linked to the patient's perspective. Orthopaedic faculty members were uncomfortable with their knowledge of this competency and their ability to teach and assess it. CONCLUSIONS: Teaching the systems-based practice competency occurs inconsistently, and formal assessment occurs infrequently. In addition to formal teaching, learning systems-based practice will be best achieved experientially and from the patient's perspective.

Genome-wide characterization of the SloR metalloregulome in Streptococcus mutans.

Streptococcus mutans is the primary causative agent of human dental caries, a ubiquitous infectious disease for which effective treatment strategies remain elusive. We investigated a 25-kDa SloR metalloregulatory protein in this oral pathogen, along with its target genes that contribute to cariogenesis. Previous studies have demonstrated manganese- and SloR-dependent repression of the sloABCR metal ion transport operon in S. mutans. In the present study, we demonstrate that S. mutans coordinates this repression with that of certain virulence attributes. Specifically, we noted virulence gene repression in a manganese-containing medium when SloR binds to promoter-proximal sequence palindromes on the S. mutans chromosome. We applied a genome-wide approach to elucidate the sequences to which SloR binds and to reveal additional "class I" genes that are subject to SloR- and manganese-dependent repression. These analyses identified 204 S. mutans genes that are preceded by one or more conserved palindromic SloR recognition elements (SREs). We cross-referenced these genes with those that we had identified previously as SloR and/or manganese modulated in microarray and real-time quantitative reverse transcription-PCR (qRT-PCR) experiments. From this analysis, we identified a number of S. mutans virulence genes that are subject to transcriptional upregulation by SloR and noted that such "class II"-type regulation is dependent on direct SloR binding to promoter-distal SREs. These observations are consistent with a bifunctional role for the SloR metalloregulator and implicate it as a target for the development of therapies aimed at alleviating S. mutans-induced caries formation.

NK cell survival mediated through the regulatory synapse with human DCs requires IL-15Ralpha.

DCs activate NK cells during innate immune responses to viral infections. However, the composition and kinetics of the immunological synapse mediating this interaction are largely unknown. Here, we report the rapid formation of an immunological synapse between human resting NK cells and mature DCs. Although inhibitory NK cell receptors were polarized to this synapse, where they are known to protect mature DCs from NK cell lysis, the NK cell also received activation signals that induced mobilization of intracellular calcium and CD69 upregulation. The high-affinity component of the receptor for IL-15, IL-15Ralpha, accumulated at the synapse center on NK cells, and blocking of IL-15Ralpha increased NK cell apoptosis and diminished NK cell survival during their interaction with DCs. Furthermore, IL-15Ralpha-deficient NK cells, obtained from donors with a history of infectious mononucleosis, showed diminished survival in culture with DCs. Synapse formation was required for IL-15Ralpha-mediated NK cell survival, because synapse disruption by adhesion molecule blocking decreased DC-induced NK cell survival. These results identify what we believe to be a novel regulatory NK cell synapse with hallmarks of spatially separated inhibitory and activating interactions at its center. We suggest that this synapse formation enables optimal NK cell activation by DCs during innate immune responses.

Linezolid-resistant Staphylococcus aureus in two pediatric patients receiving low-dose linezolid therapy.

We report 2 sisters with hyper-IgE syndrome treated with daily suppressive dosages of linezolid (LZD) who developed LZD-resistant Staphylococcus aureus carrying the G2576T mutation in the 23S rRNA gene. Molecular typing suggested transmission of the resistant strain from one sister to the other. LZD-susceptible S. aureus was isolated 2 months after LZD discontinuation. LZD-resistant S. aureus remains rare but may occur while receiving suppressive therapy.