Screw Fixation Alone for Scaphoid Fracture Nonunion.

Scaphoid fracture nonunion can often lead to pain, arthrosis, and disability. While typically the result of delayed diagnosis or inadequate treatment, it can sometimes occur even if the initial care was timely and appropriate. Whereas early recognition of acute fractures allows for nonoperative management, nonunions frequently require surgical treatment. Traditionally, this has involved open debridement and bone grafting. However, some publications suggest that certain stable nonunions may be amenable to percutaneous debridement and fixation without formal bone grafting. Although certain characteristics appear to be appropriate indications for such management, well-designed clinical studies are needed to better define them.

Proximal Row Carpectomy.

Proximal row carpectomy (PRC) has earned a respected place in the hand surgeon's armamentarium. Prerequisites for the standard PRC are good cartilage on the proximal pole of capitate and in the lunate fossa of radius. If there is cartilage damage on the proximal pole of capitate, the modification of Salomon and Eaton is a reasonable alternative to the standard PRC. The most important surgical step is preservation of the radioscaphocapitate ligament. Good long-term results can be achieved, and with careful patient selection the operation can be done successfully in people who use their hands for heavy work.

Modified AO arthrodesis of the wrist (with proximal row carpectomy).

A technique that has proven highly predictable and successful for arthrodesis of the wrist involves combining rigid internal fixation with concomitant removal of the proximal carpal row bones, which are then morselized and used for bone graft. Advantages of this procedure are (1) no distant bone graft site is required and (2) rigid internal fixation allows virtually immediate rehabilitation.

Accuracy of Carpal Tunnel Injection: A Prospective Evaluation of 756 Patients.

Background: Corticosteroid injection into the carpal tunnel is both a diagnostic test and a therapeutic modality in the treatment of carpal tunnel syndrome. Many injection techniques are described in the literature. Improper placement of injection may result in damage to neurovascular structures in the carpal canal or decrease efficacy of the test and/or therapy. The purpose of this study is to determine if carpal tunnel injection using anatomic landmarks is reproducible and safe. A review of the senior author's injection technique is presented. Methods: Over 8 years, there were 756 attempted placements of a 25-gauge needle into the carpal tunnel in a simulated carpal tunnel injection prior to open carpal tunnel release. The needle was inserted at the wrist crease, just ulnar to palmaris longus. Open carpal tunnel release was subsequently performed, and position of the needle was recorded. Results: In 572 patients (75.7%), the needle was found to be in the carpal tunnel without penetration of contents. The needle was in the carpal tunnel but piercing the median nerve in 66 attempts (8.7%). The carpal tunnel was missed in 118 attempts (15.6%). Conclusions: This is the largest study looking at accuracy of carpal tunnel injection using anatomic landmarks. Our injection accuracy (75.7%) is less than reported in previous studies, which note 82% to 100% accuracy using the same injection technique. This may indicate that carpal tunnel injection is less reliable than previously thought. Safety of carpal tunnel injection remains an important concern. The median nerve was penetrated in 8.7% of attempts.

The Flipped Classroom: An Innovative Approach to Medical Education in Ophthalmology.

OBJECTIVE: The aim of the study is to report the creation of a flipped ophthalmology course and preclinical medical student perceptions and knowledge gains before and after a flipped ophthalmology course. DESIGN: The form of the study discussed is an observational study. SUBJECTS: The subjects involved in the study are second-year (U.S.) United States medical students at the University of Miami, Miller School of Medicine (n = 401). METHODS: Second-year medical students participated in a 1-week "flipped classroom" ophthalmology course geared toward primary care providers at the University of Miami, Miller School of Medicine. Eleven hours of traditional classroom lectures were condensed into 4.5 hours of short videos with self-assessment quizzes, small group discussions, and a large group case-based discussion. Fifty-seven short videos (<9 minutes) focused on major ophthalmology topics and common conditions were viewed by the students at their leisure. Students completed a pre- and post-course evaluation on their perceptions and opinions of the flipped classroom approach. Final exam scores in the flipped classroom cohort were compared with the final exam scores in the traditional didactic format used in years prior. MAIN OUTCOME MEASURES: The main outcome measures include: student final exam performance; student satisfaction, opinions, and perceptions. RESULTS: Over the course of 2 years, 401 second-year U.S. medical students participated in the flipped classroom ophthalmology course. The majority of students enjoyed the flipped classroom experience (75.3%) and expressed interest in using the approach for future lessons (74.6%). The flipped classroom videos were preferred to live lectures (61.2%). Over 90% of students stated the self-assessment quizzes were useful, 79% reported that the small group discussions were an effective way to apply knowledge, and 76% cited the large group case-based discussion as useful. Pre-course knowledge assessment scores averaged 48%. Final examination scores in the flipped group (average ± standard deviation [SD] = 92.1% ± 6.1) were comparable to that of the traditional group when evaluating identical questions (average ± SD = 91.7% ± 5.54), p = 0.34. CONCLUSION: The flipped classroom approach proved to be a well-received and successful approach to preclinical medical education for ophthalmology. This was achieved using 35% less course time than our traditional course. This innovative approach has potential for expansion to other medical schools, medical education abroad, and for other medical school modules.

Detection of gram-negative histamine-producing bacteria in fish: a comparative study.

Poisoning due to ingestion of foods with elevated levels of biogenic amines (histamine, putrescine, cadaverine, and tyramine) is well documented. Histamine fish poisoning largely is due to growth of naturally occurring bacteria associated with scombroid fish species. A rapid and reliable method is needed to screen for the presence of histamine-forming bacteria in fish. This study included a comparison of three methods for the detection of histamine-producing bacteria. A total of 152 histamine-producing and non-histamine-producing bacteria from multiple sources were screened using a modified Niven's agar method, a potentiometric method, and a PCR-based assay targeting a 709-bp fragment of the histidine decarboxylase gene. Histamine production by bacterial isolates was confirmed by high-performance liquid chromatography (HPLC). Bacterial strains were categorized as producing high amounts of histamine, low amounts of histamine, or no histamine. Of the 152 strains tested, 128 (84%) were positive with the Niven's agar method, 73 (48%) were positive with the potentiometric technique, and 74 (49%) were positive with the PCR assay. Overall, a 38% false-positive rate was observed with the modified Niven's agar method, although this method detected both low-histamine and high-histamine strains. There was a high degree of concordance (> 99%) between results of the potentiometric and PCR methods, but neither of these methods detected low-histamine bacteria. These observations support the need for a simple and straightforward yet sensitive method for detecting histamine-producing bacteria in seafood and environmental samples.

Foundational Elements of School-Specific Augmented Medical Education.

Recent efforts to enrich the medical education experience recommended interinstitutional and collaborative efforts. Within this context, the author describes a model for school-specific augmented medical education. The evidence-backed conceptual model is composed of six foundational elements, which include the following: technology-enriched learning environments, analytics to drive instructional interventions, cognitive neuroscience and educational psychology research (the Science of Learning), self-regulated learning strategies, competency-based approaches, and blended learning instructional design. Harnessing the creativity of our leadership, medical educators, and learners is fundamental to improving the learning experience for all. This model could be used to meaningfully guide implementation processes.

Correlation between muscle morphology of the transverse carpal ligament and branching pattern of the motor branch of median nerve.

PURPOSE: This was an intraoperative anatomical study to identify the prevalence of variations in the motor branch of median nerve and to correlate these with the presence of a transverse carpal ligament (TCL) with superficial or interposed muscle. METHODS: Over a period of 12 years in 1400 consecutive patients in whom the carpal tunnel was opened for any reason, observations were made in each hand to (1) determine the presence or absence of muscle fibers lying superficial to or within the TCL and (2) identify the anatomic branching patterns of the motor branch of median nerve. The primary objective was to ascertain whether the appearance of the TCL could be used to predict the anatomy of the motor branch. RESULTS: A normal motor branch arising beneath a purely ligamentous TCL was found in 1011 hands (72%). The focus of this paper is on the remaining 386 hands (28%), in which muscle fibers were found lying superficial to or within the TCL; in this group, only 29 hands (8%) had a normal motor branch. An anomalous motor branch was found in 93% of hands with a TCL with superficial or interposed muscle fibers and in less than 1% of hands with a purely ligamentous TCL. CONCLUSIONS: In exposing the carpal tunnel, special care should be taken by the surgeon to identify and protect the motor branch when muscle fibers are encountered superficial to or within the TCL.

Radiographic spectrum of severity in Madelung's deformity.

PURPOSE: To establish whether Madelung's deformity demonstrates a radiographic continuum of severity and whether a forme fruste does exist. METHODS: Ulnar tilt, lunate subsidence, palmar carpal displacement, and lunate fossa angle were measured in 81 wrist radiographs with obvious or suspected Madelung's deformity. Statistical analyses based on these measurements were performed to ascertain if there is a deformity continuum. RESULTS: Ranges of 15 degrees to 51 degrees (mean, 28 degrees) for ulnar tilt, -7 to +11 mm (mean, -0.8 mm) for lunate subsidence, 9 to 25 mm (mean, 15.3 mm) for palmar carpal displacement, and 20 degrees to 56 degrees (mean, 33 degrees) for lunate fossa angle were obtained. Significant correlations were observed between all measurements. CONCLUSIONS: Madelung's deformity encompasses a spectrum of radiographic abnormality. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic I.

American Orthopaedic Surgeons in World War I.

On April 6, 1917, the United States declared war on Germany and entered what was then called the Great War. Among the first officers sent to Europe were 21 orthopaedic surgeons in the so-called First Goldthwait Unit. Prior to the war, orthopaedics had been a nonoperative "strap-and-buckle" specialty that dealt primarily with infections, congenital abnormalities, and posttraumatic deformity. The Great War changed all of that forever, creating a new surgical specialty with emphasis on acute treatment, prevention of deformity, restoration of function, and rehabilitation.

The effects of below-elbow immobilization on driving performance.

INTRODUCTION: There is limited research to guide physicians and patients in deciding whether it is safe to drive while wearing various forms of upper extremity immobilization. The purpose of this study is to evaluate the effect of below-elbow removable splints and fiberglass casts on automobile driving performance. METHODS: 20 healthy subjects completed 10 runs through a closed, cone-marked driving course while wearing a randomized sequence of four different types of immobilization on each extremity (short arm thumb spica fiberglass cast, short arm fiberglass cast, short arm thumb spica splint, and short arm wrist splint). The first and last driving runs were without immobilization and served as controls. Performance was measured based on evaluation by a certified driving instructor (pass/fail scoring), cones hit, run time, and subject-perceived driving difficulty (1-10 analogue scoring). RESULTS: The greatest number of instructor-scored failures occurred while immobilized in right arm spica casts (n=6; p=0.02) and left arm spica casts (n=5; p=0.049). The right arm spica cast had the highest subject-perceived difficulty (5.2±1.9; p<0.001). All forms of immobilization had significantly increased perceived difficulty compared to control, except for the left short arm splint (2.5±1.6; p>0.05). There was no significant difference in number of cones hit or driving time between control runs and runs with any type of immobilization. CONCLUSIONS: Drivers should use caution when wearing any of the forms of upper extremity immobilization tested in this study. All forms of immobilization, with exception of the left short arm splint significantly increased perceived driving difficulty. However, only the fiberglass spica casts (both left and right arm), significantly increased drive run failures due to loss of vehicle control. We recommend against driving when wearing a below-elbow fiberglass spica cast on either extremity.

Detection and identification of histamine-producing bacteria associated with harvesting and processing mahimahi and yellowfin tuna.

Histamine poisoning is one of the most common chemically induced seafoodborne illnesses reported in the United States today. The causative agents are biogenic amines, commonly produced by gram-negative bacteria. The purpose of this study was to detect and identify histamine-producing bacteria associated with standard industry practices during the harvesting, receiving, and processing of mahimahi and yellowfin tuna in North Carolina. Twenty-nine composite samples were obtained from 18 mahimahi and 11 yellowfin tuna and analyzed for their histamine content. No sample analyzed exceeded 2 ppm histamine, the lower detection limit. Composite fish muscle and environmental samples were screened (n = 386) for the presence of histamine-producing bacteria. Twenty-six percent (145) of 549 isolates selected on the basis of their morphological characteristics tested positive on Niven's media. Sixty-three Niven-positive isolates were gram negative, and 58 were gram positive. Of the 43 isolates tested further, 5 were confirmed as histamine producers, and all 5 produced at low levels (< 250 ppm in 48 h at > 15 degrees C). Three gram-negative and two gram-positive isolates were identified as Enterobacter cloacae and Staphylococcus kloosii, respectively. This study revealed that gram-negative bacteria might not be solely responsible for histamine production in at-risk fish. The confirmation of histamine-producing bacteria demonstrates the potential risk for histamine production. However, no detectable levels were found in the composite fish muscle samples analyzed even though 60% of the yellowfin tuna harvested did not meet the U.S. Food and Drug Administration's regulatory hazard analysis critical control point guidelines for temperature reduction. Therefore, no seafood safety risks were found under the standard industry practices observed in this study.

Control of Histamine-Producing Bacteria and Histamine Formation in Fish Muscle by Trisodium Phosphate.

Scombrotoxin fish poisoning remains the primary cause of seafood poisoning outbreaks despite preventive guidelines. The purpose of this study was to investigate the use of pH for the control of growth and histamine formation by histamine-producing bacteria in fish muscle. We examined pH effects on growth and histamine formation in tuna fish infusion broth and in inoculated tuna and mahi-mahi fish muscle. Histamine production was significantly less for all bacterial strains at pH 8.5 compared to pH 5.5 in tuna fish infusion broth with no significant difference in growth. Elevated pH due to phosphate treatment of fish muscle tissues significantly reduced histamine formation with no effect on the growth of histamine-producing bacteria. This study revealed that phosphate treatment of mahi-mahi and tuna fish muscle resulted in significantly lower histamine production over 4 d of storage at 10 °C. Phosphate treatment of fish muscle may serve as a secondary barrier in addition to FDA recommended time and temperature controls for reducing public health concerns of scombrotoxin fish poisoning.

Compression screw fixation without bone grafting for scaphoid fibrous nonunion.

PURPOSE: Bone graft is often recommended as an adjuvant for treatment of scaphoid nonunions. However, recent literature has suggested that fibrous nonunion may be suited to treatment with rigid fixation without bone grafting. This work reported on outcomes of compression screw fixation for established scaphoid fibrous nonunions without bone graft. METHODS: Fourteen patients underwent surgical compression screw fixation without bone grafting of scaphoid fibrous nonunion between January 1, 2000, and December 31, 2012, with minimum follow-up until the time of clinical and radiographic healing. Fibrous nonunion of the scaphoid was defined as a scaphoid fracture with all of the following features: (1) persistent tenderness, (2) incomplete trabecular bridging on three X-ray views, (3) injury that had occurred at a minimum of 6 months prior to surgery, and (4) identification of fibrous union at the time of surgery. Outcomes were assessed with range of motion assessment, Disability of the Arm, Shoulder and Hand (DASH) scores, and plain radiographs. RESULTS: Twelve of the 14 patients healed successfully, while two patients required secondary vascularized bone grafting. Both unhealed patients sustained proximal pole fractures and had a duration of ≥1 year from injury to surgery. Average time to healing was 4.4 ± 2.0 months. Average flexion was 73 ± 22° and average extension was 66 ± 22° postoperatively. Average grip strength was 90 ± 25 lbs on the operative side. Mean postoperative pain score was 1.4 (range, 0 to 7). Mean postoperative DASH score was 10.2 (range, 0 to 52). Increasing age and an interval from injury to surgery of >1 year correlated with worse DASH and pain scores. CONCLUSIONS: Patients with fibrous scaphoid nonunion demonstrated good results with rigid fixation without bone grafting. Increasing age and >1-year interval between injury and surgery resulted in lower self-assessed outcomes. LEVEL OF EVIDENCE: Therapeutic Level IV, retrospective case series.

Identifying tissue-enriched gene expression in mouse tissues using the NIH UniGene database.

There is considerable interest in the gene expression profiles that underpin the phenotypes of cells and tissues. We have developed Bioperl scripts for mining the National Institutes of Health (NIH) UniGene databases to identify this tissue-enriched gene expression. UniGene imports expressed sequence tags (ESTs) from the NIH dbEST database and clusters them by searching for sequence matches. In principle, each UniGene cluster represents the product(s) of a single transcriptional unit in the genome. This transcriptional unit can be expressed in a range of cell types, and UniGene clusters reflect these heterogeneous origins. UniGene clusters containing ESTs expressed predominantly or uniquely by one tissue will show a high proportion of ESTs from that tissue. Our Bioperl scripts parse the NIH UniGene data files as a starting point for an in-house UniGene database. Each UniGene cluster is then assessed for the total number of ESTs from a specified set of dbEST libraries and the total number of ESTs in the cluster. The ratio of the two gives a measure of enrichment. In this paper, we identify tissue-enriched gene expression in mouse pancreas, mammary gland and heart. Each tissue-enriched expression profile identifies genes that are recognisably characteristic of the respective tissue. It also identifies significant numbers of tissue-enhanced UniGenes that are derived from transcriptional units with no known function. These genes may play important and specialised functions in the tissue in question and offer targets for drug action.

Development of molecular-based methods for determination of high histamine producing bacteria in fish.

Histamine (or scombroid) fish poisoning is a significant cause of food borne disease in the United States. In this study, we describe the development of a molecular-based technique which uses digoxigenin (DIG) labeled DNA probes for the detection of gram negative bacteria producing high amounts of histamine (>1000 ppm). A cocktail of PCR amplification fragments corresponding to a 709 bp fragment of the histidine decarboxylase (hdc) gene of four high producing bacteria (Morganella morganii, Enterobacter aerogenes, Raoultella planticola and Photobacterium damselae) was DIG-labeled and screened against a strain bank of 152 gram negative bacteria isolated from scrombroid fish and their harvest environment. The probe cocktail reacted specifically (100%) with the high histamine producing strains but failed to react with low histamine producers and non-producers. To further evaluate the feasibility of the approach, fish homogenate inoculated with known concentrations of four high histamine producing bacterial strains was plated on modified Niven's medium (culture method) and trypticase soy agar supplemented with 2% NaCl (for colony lift hybridization). The colony lift hybridization counts did not differ significantly from the level of the initial inoculum (p>0.05), while the modified Niven's counts were significantly lower (p<0.05) than either inoculum or colony lift counts. The use of digoxigenin (DIG) labeled DNA probes with colony lift hybridization shows promise for accurate and specific enumeration of histamine producing bacteria in scombroid fish.