Cost-Effectiveness Analysis of Nonoperative Management Versus Early Drilling for Stable Osteochondritis Dissecans Lesions of the Knee in Skeletally Immature Patients.

PURPOSE: To evaluate the cost-effectiveness of a trial of nonoperative management versus early drilling in the treatment of skeletally immature patients with stable osteochondritis dissecans (OCD) of the knee. METHODS: A decision tree model was used to compare the cost-effectiveness of a trial of nonoperative management versus early drilling (within 6 weeks of the first office visit) from payer and societal perspectives over a 3-year time horizon. Relevant transition probabilities, costs (in 2019 US dollars based on Medicare reimbursement), health state utilities, and times to healing were derived from the literature. The principal outcome measure was the incremental cost-effectiveness ratio (ICER). One- and 2-way sensitivity analyses were performed on pertinent model parameters to validate the robustness of the base-case results using a conservative willingness-to-pay (WTP) threshold of $50,000 per quality-adjusted life-year (QALY). The Consolidated Health Economic Evaluation Reporting Standards checklist for reporting economic evaluations was used. RESULTS: In the base-case analysis from a payer perspective, early drilling was more effective (2.51 versus 2.27 QALYs), more costly ($4,655 versus $3,212), and overall more cost-effective (ICER $5,839/QALY) relative to nonoperative management. In the base-case analysis from a societal perspective, early drilling dominated nonoperative management owing to its increased effectiveness (2.51 versus 2.27 QALYs) and decreased cost ($13,098 versus $18,149). These results were stable across broad ranges on sensitivity analysis. Based on 1-way threshold analyses from a payer perspective, early drilling remained cost-effective as long it cost less than $19,840, the disutility of surgery was greater than -0.40, or the probability of successful early drilling was greater than 0.62. CONCLUSIONS: Although the traditional approach to stable OCD lesions of the knee in skeletally immature patients has been a trial of nonoperative management, our data suggest that early drilling may be cost-effective from both payer and societal perspectives. LEVEL OF EVIDENCE: III, economic and decision analysis.

Open Reduction of Medial Epicondyle Fractures in the Pediatric Population: Supine Versus Prone Position.

BACKGROUND: Operative treatment of medial epicondyle fractures can be performed in either a supine or prone position. In the supine position, fracture visualization is sometimes difficult due to the posterior position of the medial epicondyle. However, the prone position requires extensive patient repositioning but may improve visualization. The purpose of this study was to compare the results and complications between the supine and prone position when treating medial epicondyle fractures. METHODS: In a retrospective chart review, patients below 18 who underwent open reduction and internal fixation of an acute medial epicondyle fracture from January 2011 to August 2019 were identified. Patients with <2 months follow-up and concomitant fractures were excluded. Surgical variables, outcomes, and complications were recorded and compared between the supine and prone positions. RESULTS: Sixteen surgeons treated the 204 patients evaluated in this study. The mean age was 11.7 years. In all, 122 (60%) patients were treated in the supine position, and 82 (40%) in the prone position. The mean time in the room was 113 minutes in the supine group, and 141 minutes in the prone group (P<0.001). Tourniquet time was similar between groups (P=0.4). Displacement of the fracture on the first postoperative x-rays was 2.06 mm for the supine position and 1.1 mm for the prone position (P<0.001). We also found good interobserver and intraobserver reliability for the measurements. Five patients (2.5%) required reoperation due to stiffness, 2 patients due to nonunion, 1 patient due to tardy ulnar nerve palsy, and 53 (26%) had surgical hardware removal. The surgical position was not associated with complications or reoperation. CONCLUSIONS: While the prone position requires additional time in the operating room, presumably for positioning, the length of the surgical procedure itself does not differ between the 2 positions. Although the trend of the surgeons at our center is towards the prone position, with surgeons that try it usually doing all their subsequent cases that way, both positions provide excellent clinical outcomes with minimal complications. LEVEL OF EVIDENCE: Therapeutic level III-retrospective cohort study.

Pediatric Type II Tibial Spine Fractures: Addressing the Treatment Controversy With a Mixed-Effects Model.

BACKGROUND: Tibial spine fractures, although relatively rare, account for a substantial proportion of pediatric knee injuries with effusions and can have significant complications. Meyers and McKeever type II fractures are displaced anteriorly with an intact posterior hinge. Whether this subtype of pediatric tibial spine fracture should be treated operatively or nonoperatively remains controversial. Surgical delay is associated with an increased risk of arthrofibrosis; thus, prompt treatment decision making is imperative. PURPOSE: To assess for variability among pediatric orthopaedic surgeons when treating pediatric type II tibial spine fractures. STUDY DESIGN: Cross-sectional study. METHODS: A discrete choice experiment was conducted to determine the patient and injury attributes that influence the management choice. A convenience sample of 20 pediatric orthopaedic surgeons reviewed 40 case vignettes, including physis-blinded radiographs displaying displaced fractures and a description of the patient's sex, age, mechanism of injury, and predominant sport. Surgeons were asked whether they would treat the fracture operatively or nonoperatively. A mixed-effects model was then used to determine the patient attributes most likely to influence the surgeon's decision, as well as surgeon training background, years in practice, and risk-taking behavior. RESULTS: The majority of respondents selected operative treatment for 85% of the presented cases. The degree of fracture displacement was the only attribute significantly associated with treatment choice (P < .001). Surgeons were 28% more likely to treat the fracture operatively with each additional millimeter of displacement of fracture fragment. Over 64% of surgeons chose to treat operatively when the fracture fragment was displaced by ≥3.5 mm. Significant variation in surgeon's propensity for operative treatment of this fracture was observed (P = .01). Surgeon training, years in practice, and risk-taking scores were not associated with the respondent's preference for surgical treatment. CONCLUSION: There was substantial variation among pediatric orthopaedic surgeons when treating type II tibial spine fractures. The decision to operate was based on the degree of fracture displacement. Identifying current treatment preferences among surgeons given different patient factors can highlight current variation in practice patterns and direct efforts toward promoting the most optimal treatment strategies for controversial type II tibial spine fractures.

ADP-ribosylation factor 6 regulates insulin secretion through plasma membrane phosphatidylinositol 4,5-bisphosphate.

ADP-ribosylation factor 6 (ARF6) is a small GTP-binding protein that regulates peripheral vesicular trafficking and actin cytoskeletal dynamics, and it has been implicated as critical to regulated secretion. Expression of a dominant-inhibitory ARF6 mutant, ARF6(T27N), impaired glucose-, depolarization-, and gamma-thio-GTP-stimulated insulin secretion in the pancreatic beta cell line, MIN6. In response to depolarization, MIN6 cells expressing ARF6(T27N) displayed an unaltered initial fast phase but an impaired subsequent slow phase of insulin secretion. Actin cytoskeletal disassembly with latrunculin A enhanced insulin secretion, whereas stabilization with jasplakinolide inhibited secretion, consistent with the actin cytoskeleton serving as a barrier to exocytosis in these cells. ARF6(T27N) led to a depolarization-dependent reduction in the levels of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] with a time course that paralleled the inhibition of secretion. Moreover, blockade of PI(4,5)P2-dependent events by expression of a lipid-binding protein resulted in inhibition of depolarization-induced secretion in a manner identical to ARF6(T27N). These results indicate that ARF6 is required to sustain adequate levels of PI(4,5)P2 during periods of increased PI(4,5)P2 metabolism such as regulated secretion.