Background An initial anterior cruciate ligament (ACL) tear can be treated with surgical reconstruction or focused rehabilitation. The KANON (Knee Anterior cruciate ligament, NON-surgical versus surgical treatment) randomized control trial compared rehabilitation plus early ACL reconstruction (ACLR) to rehabilitation plus optional delayed ACLR and found no difference at two years by intention to treat analysis of total KOOS scores. The purpose of this study was to compare the cost-effectiveness of early versus delayed ACLR. Methods A Markov decision model was constructed for a cost-utility analysis of early reconstruction (ER) versus rehabilitation plus optional delayed reconstruction (DR). Outcome probabilities and effectiveness were derived from two sources: the KANON Study and the Multicenter Orthopaedic Outcomes Network (MOON) database. Collectively, these two sources provided data from 928 ACL patients. Utilities were measured by the SF-6D. Costs were estimated from the societal perspective in 2012 U.S. dollars. Costs and utilities were discounted in accordance with the United States Panel on Cost-Effectiveness in Health and Medicine. Effectiveness was expressed in quality-adjusted life years gained (QALYs). Principal outcome measures were average incremental costs, incremental effectiveness (as measured by QALYs), and net health benefits. Willingness-to-pay was set at $50,000, the currently accepted standard in the U.S. Results In the base case, the ER group resulted in an incremental gain of 0.28 QALYs over the DR group with a corresponding lower overall cost to society of $1572. Effectiveness gains were driven by the low utility of an unstable knee and the lower utility for the DR group. The cost of rehabilitation and the rate of additional surgery drove the increased cost of the DR group. The most sensitive variable was the rate of knee instability after initial rehabilitation. When the rate of instability falls to 51.5%, rehabilitation plus optional delayed ACLR is less costly and when it falls below 18% it becomes the preferred cost-effective strategy. Conclusions An economic analysis of the timing of ACLR using data exclusively from the KANON trial, MOON cohort, and national average reimbursement revealed that early ACLR was more effective (improved QALYs) at a lower cost than rehabilitation plus optional delayed ACLR. Therefore, early ACLR should be the preferred treatment strategy from a societal health system perspective.

This study aimed to compare medial compartment contact pressures in knees treated with medial meniscal transplantation using either a bone plug or bone trough technique. Peak pressure, mean pressure, and contact area of the medial compartment were determined in 8 cadaveric specimens at 0° and 30° of flexion under a 1000-N load. Contact mechanics were measured for the intact knee, after meniscectomy, and after medial meniscal transplant with either a bone plug technique or a bone trough technique. Total medial meniscectomy resulted in decreased contact area, increased medial contact pressure, and increased medial peak contact pressure. When comparing meniscal transplant techniques at both 0° and 30°, no significant difference (P<0.05) was noted regarding contact mechanics after transplantation. The bone trough technique shows similar contact mechanics to the double bone plug technique and maintains the natural hoop stress of the meniscus during medial meniscal transplantation.[J Knee Surg. 2008;21:20-26.]

This study revealed that preoperative physiologic passive knee HE ≥5° is present in one-third of patients who undergo revision ACLR. HE ≥5° was an independent significant predictor of graft failure after revision ACLR with a >2-fold OR of subsequent graft rupture in revision ACL surgery. Registration: NCT00625885 ( ClinicalTrials.gov identifier).

SummaryPlant xylem cells conduct water and mineral nutrients. Although most plant cells are totipotent, xylem cells are unusual and undergo terminal differentiation. Many genes regulating this process are well characterized, including the VASCULAR-RELATED NAC DOMAIN7 (VND7), MYB46 and MYB83 transcription factors which are proposed to act in interconnected feed-forward loops. Much less is known regarding the dynamic behavior underlying the terminal transition to xylem cell differentiation. Here we utilize whole root and single cell data to mathematically model this relationship. These provide evidence for VND7 regulating bistable switching of cells in the root to a xylem cell identity, with additional features of hysteresis. We further determine that although MYB46 responds to VND7 induction, it is not inherently involved in executing the binary switch. A novel regulatory architecture is proposed that involves four downstream targets of VND7 that act in a cycle. These data provide an important model to study the emergent properties that may give rise to totipotency relative to terminal differentiation and reveal novel xylem cell subtypes.

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We instituted a training program to improve the overall accuracy of medical record coding through greater physician awareness to enhance hospital reimbursement and maintain quality patient care. A physician-targeted course reviewed the prospective payment system, diagnosis-related group guidelines, ambulatory surgery reimbursement, and the relationship between accurate physician documentation and medical record coding. Annual increases in charges from prospective surgical case assignment, proper conversion of outpatient to inpatient status, and more accurate coding of inpatient comorbidities and complications led to an estimated increase in hospital charges of $1.6 million.