Defining patient acceptable symptom state thresholds for commonly used patient reported outcomes measures in general orthopedic practice.

BACKGROUND: Patient reported outcomes measures are distributed regularly within musculoskeletal physical therapy practice in an effort to track patient progress and response to treatment. A number of studies have reported on the amount of change necessary to identify the minimal clinically important difference. Few studies have identified thresholds signifying patient satisfaction with treatment and what patient specific factors may be influential in identifying patient satisfaction. OBJECTIVES: To identify thresholds amongst commonly used patient reported outcomes measures associated with the patient acceptable symptom state (PASS). To identify the confounding effects of demographic and psychosocial variables on reported PASS estimates. DESIGN: Prospective cohort study. METHOD: A sample of convenience consisting of consecutive patients referred for outpatient physical therapy for general orthopaedic conditions fulfilling the eligibility criteria were included. All patients completed baseline demographic information as well as baseline pain and functional outcomes measures. The PASS question was used as the anchor in this study to identify patient thresholds. Patients completed outcomes measures every 2 weeks and at patient discharge. PASS thresholds were identified using receiver-operating curves maximizing sensitivity and specificity. RESULTS: PASS thresholds were found to vary depending on baseline pain levels, functional status, socioeconomic status, educational level, and psychosocial status. CONCLUSIONS: Multiple factors are influential in determining patient success following treatment. Clinicians should be aware of patient baseline pain and functional status as well as socioeconomic status, educational level, and psychosocial status and stratify patients accordingly when determining patient prognosis and developing a plan of care.

Microfluidics for High School Chemistry Students.

We present a laboratory experiment that introduces high school chemistry students to microfluidics while teaching fundamental properties of acid-base chemistry. The procedure enables students to create microfluidic systems using nonspecialized equipment that is available in high school classrooms and reagents that are safe, inexpensive, and commercially available. The experiment is designed to ignite creativity and confidence about experimental design in a high school chemistry class. This experiment requires a computer program (e.g., PowerPoint), Shrinky Dink film, a readily available silicone polymer, weak acids, bases, and a colorimetric pH indicator. Over the span of five 45-min class periods, teams of students design and prepare devices in which two different pH solutions mix in a predictable way to create five different pH solutions. Initial device designs are instructive but rarely optimal. During two additional half-class periods, students have the opportunity to use their initial observations to redesign their microfluidic systems to optimize the outcome. The experiment exposes students to cutting-edge science and the design process, and solidifies introductory chemistry concepts including laminar flow, neutralization of weak acids-bases, and polymers.

Proprioception of the knee before and after anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study was to determine, first, if there is measurable deficit in proprioception in an anterior cruciate ligament (ACL)-deficient knee, either compared to the contralateral knee or external controls; second, if this deficit, if present, improves after ACL reconstruction; and third, if improvement occurs, what the time course of improvement is. TYPE OF STUDY: Prospective cohort study. METHODS: Patients undergoing ACL reconstruction at the University of Chicago, demonstrating a full and painless range of motion and no other knee ligament injury or history of previous knee surgery, were eligible. Twenty-six patients, with an average age of 25 years (range, 16 to 48) were enrolled. Average time from injury to reconstruction was 8 weeks. The patients' contralateral knee served as an internal control, and 26 age-matched and gender-matched healthy volunteers were enrolled as an external control group. ACL reconstructions were performed using a single-incision technique with either bone-patellar tendon-bone or quadrupled hamstring autograft. They were allowed immediate weightbearing as tolerated and participated in a standardized rehabilitation program, with the goal of returning to sport at approximately 6 months. Proprioception testing was carried out using an electrogoniometer, in a seated position. Joint position sense (JPS) and threshold to detection of passive motion (TDPM) were measured preoperatively and at 3 and 6 weeks and 3 and 6 months postoperatively. RESULTS: Mean KT-2000 values 6 months postoperatively were 1.38 mm (+/-2). Modified Lysholm score improved significantly (P <.01). Calculated r values were 0.65 for JPS and 0.96 for TDPM. No significant differences in postoperative proprioception were found between hamstring and patellar tendon grafts or among patients with meniscus injury, meniscus repair, or chondral injury. Preoperatively, the mean TDPM in both the injured and contralateral knees was significantly higher (worse) than in the external control knees (P =.008; P =.016). Evaluation of changes in proprioception from preoperative to 6 months postoperative showed significant improvement in both injured and contralateral knees (P =.04; P =.01). At 6-month follow-up, there was no significant difference from controls. CONCLUSIONS: TDPM was a more reliable method than JPS for testing proprioception before and after ACL reconstruction in this study. Bilateral deficits in knee joint proprioception (TDPM) were documented after unilateral ACL injury. Reconstruction of a mechanical restraint (ACL graft) was believed to have a significantly positive impact on early and progressive improvement in proprioception.