Multiple Cultures and Extended Incubation for Upper Extremity Revision Arthroplasty Affect Clinical Care: A Cohort Study.

Skin flora organisms (SFOs) isolated from 1 to 2 tissue samples during shoulder and elbow revision arthroplasty are difficult to distinguish as contamination or infection. We examined the change in clinical care after implementation of an Arthroplasty Infection Protocol by increasing the number of intraoperative samples held for 10-day incubation to a minimum of 5. METHODS: Infection was defined as ≥3 cultures growing the same SFO or any one culture growing any other virulent organism. SFOs growing in 1 to 2 samples were defined as skin flora contaminant. All cases were compared with pre-Arthroplasty Infection Protocol institution standard to determine changes in microbiological diagnosis and resultant antibiotic treatment. RESULTS: Forty cases fulfilled the inclusion criteria: 50% of these were culture negative, and 35% grew Propionibacteria. When compared with the standard of obtaining one sample, this protocol altered the microbiological diagnosis and subsequent antibiotic treatment in 45% of cases (95% confidence interval 29% to 62%). This protocol had a predictive value of joint sterility in 95% of culture-negative cases (95% confidence interval 74% to 99%). DISCUSSION: The addition of 5 or more samples held for 10-day incubation reliably differentiated between joint infection, contamination, and sterility, which changed the course of care in 45% of surgical cases.

Expanding the use of simulators as assessment tools: the new pop quiz.

This study introduces a novel way to implement simulation in medical education. We investigated the feasibility of integrating a newly developed breast examination simulator into a breast exam technique lecture while also collecting detailed data on medical students' breast exam skills. Results indicate that it is feasible to integrate simulation technology into the classroom environment and collect detailed performance data that can be analyzed and used for skills assessment.

Strain effects of placing an arthroscopic portal through the subscapularis tendon.

HYPOTHESIS: The biomechanical effects of placing a portal through the subscapularis tendon have not been studied. Our hypothesis is that placing a portal through the subscapularis tendon will affect the strain properties of the tendon. MATERIALS AND METHODS: Eight shoulders from deceased donors were dissected to expose the subscapularis musculotendinous unit. The subscapularis muscle was isolated, the arm was locked at neutral (0° abduction, 0° flexion/extension, 0° external rotation/internal rotation), and 3 cables were sutured to the subscapularis musculotendinous junction. Each cable was connected to a static weight. Three differential variable reluctance transducers (DVRTs) from Microstrain were sutured into the subscapularis tendon-superior, inferior, and in line with the proposed 5 o'clock portal. The musculotendinous unit was loaded along its line of action with 3, 9, and then 15 kg. Strain at each DVRT was measured in the native subscapularis tendon at each load level. The same strain measurement was taken after placing and removing a 5-mm suture anchor through the 5 o'clock portal and in the tendon after placing and removing an 8-mm cannula. RESULTS: Penetrating the subscapularis tendon with either a 5-mm suture anchor or an 8-mm cannula does not produce any statistically significant change in strain compared with the native tendon. CONCLUSION: Placing an anchor, or even an 8-mm cannulated portal, does not significantly alter the strain properties of the subscapularis tendon. This lack of effect on the strain characteristics of the subscapularis does not preclude the possibility of clinical effects.

A simulation-based assessment of clinical breast examination technique: do patient and clinician factors affect clinician approach?

BACKGROUND: Recent publications describing widely accepted clinical breast examination (CBE) techniques have sparked interest in setting standards for CBE. In support of CBE training and assessment, the purpose of our study was to quantify CBE palpation techniques using simulation technology and assess the affects of clinical presentation and clinician background on CBE techniques. METHODS: Three sensored silicone breast models were configured to represent 3 different clinical presentations. The models were examined by 102 clinicians at a local breast cancer meeting, and their performance was captured by using sensored based data acquisition technology. RESULTS: Clinicians had significantly longer examination times on the fatty breast with no masses compared with the breast with a dominant mass and the breast with fibrocystic changes (66.37 seconds, 40.50 seconds, and 42.28 seconds, P < .05). In addition, on average, female clinicians had significantly greater examination times (females = 56.66 seconds, males = 42.09 seconds, P < .05) and touched more sensors (females = 7.97, males = 6.30, P < .05) with greater pressures (females = 5.21, males = 4.82, P < .05) than their male counterparts. CONCLUSIONS: Clinical presentation and clinician background may affect CBE technique yet does not appear to negatively affect clinician accuracy. Additional research quantifying the range of CBE techniques used in medical practice may inform CBE standardization and competency testing.