Predicting Which Species of Bacteria Will Cause an Infection After Fracture Surgery.

The aim of this study was to develop and validate risk prediction models for deep surgical site infection (SSI) caused by specific bacterial pathogens after fracture fixation. A retrospective case-control study was conducted at a level I trauma center. Fifteen candidate predictors of the bacterial pathogens in deep SSI were evaluated to develop models of bacterial risk. The study included 441 patients with orthopedic trauma with deep SSI after fracture fixation and 576 control patients. The main outcome measurement was deep SSI cultures positive for methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S aureus (MRSA), gram-negative rods (GNRs), anaerobes, or polymicrobial infection within 1 year of injury. Prognostic models were developed for five bacterial pathogen outcomes. Mean area under the curve ranged from 0.70 (GNRs) to 0.74 (polymicrobial). Strong predictors of MRSA were American Society of Anesthesiologists (ASA) classification of III or greater (odds ratio [OR], 3.4; 95% CI, 1.6-8.0) and time to fixation greater than 7 days (OR, 3.4; 95% CI, 1.9-5.9). Gustilo type III fracture was the strongest predictor of MSSA (OR, 2.5; 95% CI, 1.6-3.9) and GNRs (OR, 3.4; 95% CI, 2.3-5.0). ASA classification of III or greater was the strongest predictor of polymicrobial infection (OR, 5.9; 95% CI, 2.7-15.5) and was associated with increased odds of GNRs (OR, 2.7; 95% CI, 1.5-5.5). Our models predict the risk of MRSA, MSSA, GNR, anaerobe, and polymicrobial infections in patients with fractures. The models might allow for modification of preoperative antibiotic selection based on the particular pathogen posing greatest risk for this patient population. [Orthopedics. 2024;47(1):e19-e25.].

Venous thromboembolism in patients with surgically treated ankle fractures.

OBJECTIVES: In patients with rotational ankle fracture, we compare the rate of venous thromboembolism development between patients who received chemoprophylaxis vs those patients that received none. DESIGN: Retrospective cohort study. SETTING: Level I trauma center. PATIENTS/PARTICIPANTS: Between 2014 and 2018, we identified 483 patients with rotational ankle fracture that had no VTE risk factors, were under 70 years of age, and had an isolated injury. INTERVENTION: Chemoprophylaxis vs no chemoprophylaxis after open reduction internal fixation of a rotational ankle fracture. MAIN OUTCOME MEASUREMENTS: Development of VTE was the primary outcome. Secondary outcomes included wound problems, infection, hematoma, or non-union. RESULTS: There were 313 patients that received no prophylaxis and 170 patients that received chemoprophylaxis after operative fixation of an isolated ankle fracture. Demographics including age, gender, body mass index, and ASA class were similar between groups. The rate of DVT/PE was 3.5% in those without DVT prophylaxis, and 4.1% in those on DVT prophylaxis with no significant differences found (p = 0.8). There was no significant difference in wound complication (no VTE prophylaxis-3.7% vs VTE prophylaxis-2.5%, p = 0.7) or infection rates (no VTE prophylaxis-3.8% vs VTE prophylaxis 4.1%, p = 1.0) between groups. CONCLUSIONS: No difference was detected in the rate of symptomatic DVT or PE in patients based on chemoprophylaxis. Our results support the conclusion that the use of chemoprophylaxis may remain surgeon preference and based on patient risk factors for VTE development. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

External Validation of the Radiographic Investigation of the Distal Extension of Fractures Into the Articular Surface of the Tibia (RIDEFAST Study).

OBJECTIVE: To test the external validity of the fracture to plafond (FTP-length of fracture/distance to plafond) ratio to rule out distal intra-articular fractures (DIA) in distal tibial shaft fractures at an independent tertiary trauma center. DESIGN: Retrospective cohort study. SETTING: Two Level 1 trauma centers. PATIENTS: Two hundred seventeen patients with a distal tibial shaft fracture in the model cohort and 146 patients in the validation cohort. INTERVENTION: Radiographic measurements to calculate FTP ratio. MAIN OUTCOME MEASUREMENTS: Calibration plots, area under receiver operating characteristic curve (AUC), and decision curve analyses to evaluate the external validity of FTP ratio to determine DIA. RESULTS: The AUC for the anteroposterior (AP) FTP ratio was 0.83 [95% confidence interval (CI) 0.78-0.88] in the model data set and 0.86 (95% CI 0.80-0.91) in the validation data set. The AUC for the lateral FTP ratio was 0.82 (95% CI 0.77-0.87) in the model data set and 0.82 (95% CI 0.75-0.88) in the validation data set. The previously established AP FTP cutoff ratio of 0.61 had a 94% negative predictive value in the model cohort and a 100% negative predictive value in the validation cohort. CONCLUSION: The FTP ratio is an effective and externally validated screening tool to rule out DIA in distal tibia shaft fractures. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Techniques for predicting and avoiding unintentional biplanar movements during iliosacral screw placement.

The technique for placing iliosacral screws typically involves the surgeon using an inlet and outlet view as the primary means for assessing the anteroposterior and craniocaudal position of the guidewire, respectively. However, because these views are rarely, if ever, orthogonal to one another, this technique will inevitably lead to unintentional biplanar movements. These unintentional movements, in turn, require correction, which can increase operating room and fluoroscopic time. Here we calculate the degree and magnitude of these unintentional movements. Additionally, we provide a simple technique for minimizing or eliminating them altogether.

The Natural History of Pediatric Trigger Thumb in the United States.

PURPOSE: Surgical release of pediatric trigger thumbs has been recommended as definitive treatment, although controversy exists over the natural history of pediatric trigger thumb. This study sought to evaluate the incidence of spontaneous resolution of pediatric trigger thumb and the factors that may influence resolution. METHODS: Pediatric patients were prospectively enrolled by a single surgeon from August 2009 to July 2015. All patients were initially treated with observation. They were followed annually and we collected pain scores (Parental visual analog scale), subjective dysfunction as perceived by parents, and physical examination information including the presence of flexion contracture of the thumb interphalangeal (IP) joint, thumb metacarpophalangeal joint laxity, and medial-lateral plane IP joint angular deformity. A competing risk framework was used to estimate the cumulative incidence at 5 years from the initial visit, and a subdistribution hazards model was used to compare patient characteristics with spontaneous resolution. Hazard ratios (HRs), 95% confidence intervals (95% CIs), and P values were reported. RESULTS: Seventy-eight patients (93 thumbs) with an average age of 20 months ± 1 year (mean ± SD) were enrolled at the first clinic visit and followed for 4.3 years (interquartile range, 3.1-5.5 years). At 5 years from the initial visit, 32% (95% CI, 20%-43%) of thumbs had resolved spontaneously, and 43% (95% CI, 30%-54%) had elected to proceed to surgery. Among those who had surgery, the median time to surgery was 4.1 years (interquartile range, 2.9-5.3 years). Bilateral thumb involvement increased the risk of surgery (subdistribution HR, 2.38; 95% CI, 1.23--4.6). Each degree increase in initial IP joint flexion decreased the occurrence of spontaneous resolution by 3% (subdistribution HR, 0.97; 95% CI, 0.94-0.99). Initial IP joint flexion 30° or less was associated with spontaneous resolution at 3 years (sensitivity, 0.73, 95% CI, 0.37-1.00; specificity, 0.70, 95% CI, 0.38-0.94; positive predictive value, 0.18, 95% CI, 0.13-0.41; negative predictive value, 0.76, 95% CI, 0.71-0.83; area under the curve, 0.78), whereas only 2.5% (95% CI, 0.4%-17%) of patients with an IP joint flexion greater than 30° resolved. CONCLUSIONS: A third of pediatric trigger thumbs resolved spontaneously, but most parents desired eventual surgical release. Patients with IP joint flexion contractures greater than 30° at baseline often lacked spontaneous resolution at 3 years and may be reasonable early surgical candidates. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Closed manipulation under anesthesia for pediatric post-traumatic elbow arthrofibrosis.

BACKGROUND: Post-traumatic elbow arthrofibrosis (PEA) and its associated limitations to elbow range of motion (ROM) are a recognized consequence of trauma to the pediatric elbow. Closed manipulation under anesthesia (CMUA) of the elbow can be performed in pediatric patients as a nonoperative attempt to improve dysfunctional ROM. Minimal outcome data to support CMUA exist. The study evaluates the efficacy of CMUA for PEA in pediatric patients. METHODS: Patients younger than 18 years who underwent CMUA (Current Procedural Terminology code 24300) for PEA between 2005 and 2015 at 3 institutions were included. A retrospective chart review was performed to collect demographic data and ROM premanipulation and at last follow-up. Paired 2-tailed t tests were used to compare pre- and postmanipulation elbow ROM. RESULTS: Thirteen patients with a mean age of 12.2 ± 2.6 years (range 6.7-15.6 years) met the inclusion criteria. Median time to CMUA from initial surgery was 4.2 months (interquartile range [IQR] 3.6-8.4, range 1.4-19.7 months). Median follow-up time was 6 months with an IQR of 3.3-10.0 months. At last follow-up, there was significant improvement in elbow flexion of 22° ± 17° (P < .001) and extension of 29° ± 21° (P < .001). The average premanipulation motion arc of 60° ± 24° significantly increased to 110° ± 22° at final assessment (P < .001). CONCLUSION: CMUA appears to be a valuable alternative and reliable procedure for improving PEA in pediatric patients who exhaust nonoperative interventions.

Compartment Syndrome in Tibial Plateau Fractures: Do Previously Established Predictors Have External Validity?

OBJECTIVE: To test previously established radiographic predictors of compartment syndrome in tibial plateau fractures and determine whether novel measurements may further improve a surgeon's ability to identity patients at high risk for developing this outcome. DESIGN: Retrospective review. SETTING: Academic Level I trauma center. PATIENTS: Five hundred thirteen patients with tibial plateau fractures treated operatively over a 10-year period (OTA/AO 41B1-3 & 41C1-3; Schatzker I-VI). INTERVENTION: Previously established plain film radiographic measurements and novel computed tomography soft tissue measurements. MAIN OUTCOME MEASURE: Acute compartment syndrome (ACS). RESULTS: Schatzker VI fractures (odds ratio 5.72, confidence interval 2.55-12.83, P < 0.001), high-energy mechanism (3.10, 1.26-7.58, P = 0.0096), fibular fracture (8.14, 3.33-19.96, P < 0.0001), fracture length (9.70, 2.45-37.69, P = 0.0014), and plateau-shaft combined injury (2.97, 1.15-7.70, P = 0.019) were all associated with the development of compartment syndrome. The depth of the posterior compartment was also predictive of CS (1.06, 1.02-1.09, P = 0.0025). Patients with 3 and 4 predictive markers demonstrated a 20% and 27% chance of developing ACS respectively. CONCLUSIONS: This study confirms that several factors are associated with the development of ACS. The presence of each independent predictor had a cumulative effect such that when more than one variable is present, the chance of ACS increases. This information may be used to alert providers regarding injuries that require vigilant evaluation. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Patient Satisfaction in the Hand Surgery Clinic: An Analysis of Factors That Impact the Press Ganey Survey.

PURPOSE: Our purpose was to test the null hypothesis that no patient or clinic visit characteristics affect satisfaction of hand surgery outpatients, as measured by the Press Ganey Outpatient Medical Practice Survey (PGOMPS). METHODS: Adult patients (≥ 18 years) evaluated by 5 fellowship-trained hand surgeons between January 2014 and December 2016 for a new patient clinic visit at a single tertiary academic medical center, were included. Prospectively collected PGOMPS data were reviewed retrospectively for each visit. Chart review was performed to collect demographic and visit characteristics data. Satisfaction was defined a priori as achieving a PGOMPS score above the 33rd percentile. Both the PGOMPS Total Score (primary outcome) and Provider Subscore (secondary outcome) were analyzed using univariate and multivariable logistic regression. RESULTS: Of 748 included patients, the mean age was 51.7 ± 15.5 years, and 64% were women. Leading diagnoses included tendinitis (19%), neuropathy (19%), arthritis (16%), and fracture-dislocation (13%). Multivariable modelling of the PGOMPS Total Score revealed that older age, shorter wait times, and scheduling surgery were significantly associated with greater satisfaction. The PGOMPS Provider Sub-Score multivariable modelling revealed that older age, shorter wait times, scheduling surgery, and administering injections were significantly associated with greater satisfaction. Diagnostic category and insurance status did not affect satisfaction. CONCLUSIONS: Increasing patient age, decreased wait time, and receiving an intervention (scheduling of surgery or receiving an injection) are associated with increased satisfaction among newly presenting hand surgery clinic patients as measured by the Press Ganey Outpatient Medical Practice Survey. Diagnosis and access to health care (insurance status and distance to clinic) did not influence patient satisfaction. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.

Unstable Pelvic Ring Injuries: How Soon Can Patients Safely Bear Weight?

OBJECTIVE: To determine if time to weight bearing (WB) is associated with complications in operatively treated pelvic ring injuries. DESIGN: Retrospective cohort study. SETTING: Academic Level I trauma hospital. PATIENTS: Two hundred eighty-six patients with pelvic ring injuries treated operatively over a 10-year period [OTA/AO 61-B1-3, 61-C1-3; Young-Burgess lateral compression (LC) 1-3, anterior-posterior compression (APC) 1-3, and vertical shear] were included. INTERVENTION: Patients were stratified into early (≤8 weeks) and late (>8 weeks) time to full WB groups. MAIN OUTCOME MEASURE: Composite outcome of implant failure [broken screw(s)/plate(s), screw(s) loosening], revision surgery, and malunion. RESULTS: We identified 286 patients with a mean age of 39.9 years (range: 18-81 years) and an average follow-up of 1.2 years (1.0-9 years). There were 132 and 154 patients in the early and late WB groups, respectively. A total of 142 Young-Burgess LC-1, 48 LC-2, 23 LC-3, 10 APC-1, 45 APC-2, 8 APC-3, and 8 vertical shear injuries were noted. Complications were noted in 47 patients (16%). Complications included 18 implant failures, 16 malunions, and 13 patients who required revision operations for loss of reduction. Time to WB was not associated with composite complication rates (P = 0.24). APC-2, LC-3, and injuries with bilateral rami fractures were noted to have a higher complication rates independent of time to WB (P = 0.005, 0.03, and 0.03, respectively). CONCLUSIONS: No difference in implant failure, malunion, or early loss of reduction between operatively treated pelvic ring injuries allowed to WB as tolerated before 8 weeks compared with those who remained on protected WB protocol for any time greater than 8 weeks was noted. These data may provide information to support early WB protocols. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Evaluating the Impact of Wait Time on Orthopaedic Outpatient Satisfaction Using the Press Ganey Survey.

The Press Ganey Outpatient Medical Practice Survey is a commonly utilized questionnaire that attempts to measure satisfaction with outpatient health care. A wide variety of factors have been associated with lower satisfaction scores among orthopaedic patients, including age, sex, presence of psychological disorders, and driving distance to the point of care. The impact of clinic workflows is less clear. In this study, we hypothesized that an increased clinic wait time was an independent predictor of lower patient satisfaction as measured by the Press Ganey survey. METHODS: We retrospectively reviewed 4,216 new outpatient orthopaedic surgery visits between January 1, 2014, and December 31, 2016, at a single academic institution. For patients with multiple visits, only the first new patient visit was analyzed. Satisfaction was defined as achieving a score above the 33rd percentile of the cohort. Univariate analysis followed by multivariable binary logistic regression was used to detect factors associated with patient satisfaction. RESULTS: Of the 4,216 unique patients, the mean age (and standard deviation) was 52.8 ± 15.8 years, and 58.9% of the patients were female. The mean total wait time was 17.8 ± 19.4 minutes. Univariate analysis revealed greater odds of achieving satisfaction on the Press Ganey survey for a wait time of <15 minutes compared with a wait time of ≥15 minutes; the odds ratio (OR) was 3.78 (95% confidence interval [CI], 3.30 to 4.33; p < 0.01). The multivariable model revealed an association between satisfaction and wait time while controlling for other potential contributing factors: the odds of achieving satisfaction after waiting for 15 to 29 minutes were 0.36 (95% CI, 0.31 to 0.43; p < 0.01) compared with waiting for <15 minutes, with significantly decreasing odds (p < 0.01 for all) observed with further increments of increased wait time. CONCLUSIONS: A wait time exceeding 15 minutes in an outpatient orthopaedic clinic was an independent predictor of scoring at or below the 33rd percentile on the Press Ganey survey. Further increases in wait time significantly increased the odds of dissatisfaction. Measures to reduce clinic wait time may improve the patient experience and satisfaction with the orthopaedic encounter.

Association of Physical Function, Anxiety, and Pain Interference in Nonshoulder Upper Extremity Patients Using the PROMIS Platform.

PURPOSE: The relationship between psychosocial factors and self-reported physical function among hand and upper extremity patients is complex. The Patient-Reported Outcomes Measurement Information System (PROMIS) platform has attempted to create a variety of specifically targeted metrics that can be administered using computer adaptive testing (CAT). Three metrics measuring self-reported physical function (herein referred to in combination as "functional" metrics) include the PROMIS Physical Function (PF) CAT, PROMIS Upper Extremity (UE) CAT, and the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH). Two metrics assessing psychosocial factors include the PROMIS Anxiety and Pain Interference (PI) CATs ("nonfunctional" metrics). This study evaluates whether the functional metrics were correlated with nonfunctional metrics. METHODS: The 5 questionnaires were administered prospectively on a tablet computer to all consecutive adult patients presenting to an outpatient hand and upper extremity (nonshoulder) clinic at a tertiary academic medical center from January 1 to November 1, 2014. For patients with multiple visits during the study period, only the first was included. Data were evaluated retrospectively to assess the relationship between functional and nonfunctional measures, with Pearson correlation coefficients to understand the relationship between continuous variables, and 1-way analysis of variance to examine for differences in outcome measures across demographic groups. Multivariable linear regression analyses were performed to determine factors predicting functional disability. RESULTS: We included 1,299 patients: mean age was 46.8 years, 53% were female, and 23% were unemployed or on disability. The PROMIS PF CAT, PROMIS UE CAT, and QuickDASH scores were all significantly correlated with PROMIS Anxiety CAT (Pearson correlation coefficients, -0.46, -0.48, and 0.53, respectively) and PROMIS PI CAT (-0.60, -0.65, and 0.76, respectively) scores. Multivariable regression analyses demonstrated that increased PROMIS Anxiety and PI CAT scores each independently and adversely influenced PROMIS PF CAT, PROMIS UE CAT, and QuickDASH scores. CONCLUSIONS: Increasing levels of patient anxiety and pain interference are independently associated with decreased patient-reported upper extremity function. CLINICAL RELEVANCE: This study provides further support of the biopsychosocial model by highlighting that increased anxiety is associated with decreased self-reported function using the PROMIS platform.

Radiographic Investigation of the Distal Extension of Fractures Into the Articular Surface of the Tibia (The RIDEFAST Study).

OBJECTIVE: To determine whether radiographic measurements are predictive of involvement of the distal tibia articular surface in tibial shaft fractures. DESIGN: Retrospective review. SETTING: Academic Level-I trauma hospital. PATIENTS: Two-hundred seventeen patients with tibial shaft fractures distal to the isthmus (OTA/AO: 42-A1-3; 42-B1-3; 42-C1-3; and 43-A1-3). INTERVENTION: Analysis of anteroposterior (AP) and lateral radiographs. The following parameters were measured: (1) angle between the predominant fracture line and the plane of the tibial plafond (α-angle), (2) length of the shaft fracture, (3) distance from the most inferior extent of the shaft fracture to the tibial plafond (DTP), (4) width of the tibial plafond, (5) width of the tibial isthmus, (6) ratio of fracture length to DTP (FTP), and (7) fibular fracture distance. MAIN OUTCOME MEASURE: Distal intra-articular involvement (DIA). RESULTS: A total of 217 patients were identified, 56 (26%) with DIA. The FTP ratio as measured on both the AP (odds ratio: 8.20, confidence interval, 4.26-17.22, P < 0.0001) and lateral radiographs (10.00, 4.78-23.23, <0.0001) was the most effective screening measurement for DIA. AP and lateral FTP ratios of 0.224 and 0.255, respectively, achieved a negative predictive value of 100%, eliminating the need for computed tomography in 16%-23% of injuries. CONCLUSION: Involvement of the distal articular surface in patients with distal tibial shaft fractures is significantly associated with fracture geometry and pattern. The FTP ratio may be used as an effective screening tool to rule out of intra-articular involvement. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Treatment Approach for Infection of Healed Fractures After Internal Fixation.

OBJECTIVE: To review the efficacy of a treatment approach for patients with infection and colonized implants after open reduction and internal fixation of fractures. DESIGN: Retrospective case series. SETTING: Level one trauma center. PATIENTS: Twenty patients were treated for wound infection with colonized implants after open reduction and internal fixation. INTERVENTION: Surgical debridement, removal of implants, and a short postoperative oral antibiotic course. MAIN OUTCOME MEASUREMENT: The course of patients after surgical debridement and removal of implants, including culture results, antibiotic administration, and presence of recurrent clinical infection and radiographic union. RESULTS: Twenty patients had clinical presentations, including skin breakdown, serous drainage, purulent drainage and/or exposed implants, most commonly of the tibia (15 of 20). Mean time from index procedure to debridement with implant removal was 19.7 months. At the time of debridement and implant removal, 18 of 20 (90%) patients had a positive intraoperative culture (16 routine cultures and 2 broth cultures). The most common bacteria were Enterobacter cloacae (5/17) and methicillin-sensitive Staphylococcus aureus (4/17). All patients had soft tissue healing without signs of recurrent infection after mean follow up of 40 months after implant removal. CONCLUSIONS: Surgical debridement with implant removal plus a short oral antibiotic course is effective to resolve wound infection with a colonized implant in the setting of healed fracture after internal fixation. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Serial Radiographs Do Not Change the Clinical Course of Nonoperative Stable OTA/AO 44-B1 Ankle Fractures.

OBJECTIVE: To assess radiographic markers of ankle stability in stable OTA/AO 44-B1 ankle fractures. DESIGN: Retrospective review. SETTING: Academic Level-I trauma hospital. PATIENTS: One hundred thirty-four patients with stable OTA/AO 44-B1 (Danis-Weber B, Supination-External Rotation-II) ankle fractures. INTERVENTION: Analysis of mortise view radiographs at the time of initial evaluation and final follow-up. VARIABLES MEASURED: (1) medial clear space; (2) Mueller-Nose Distance. MAIN OUTCOME MEASURE: Change in radiographic measurements resulting in conversion to operative intervention. RESULTS: Patients followed up an average of 2.6 visits in our clinics (SD 1.06). Patients received an average of 11.2 individual radiographic images to evaluate their injury (SD 3.9, maximum 29). No patients progressed to surgery in this cohort. Mean medial clear space at the time of injury was 3.4 mm (SD 0.8) and was 3.3 mm (SD 0.7) at the time of final follow-up (P = 0.1). Mean Mueller-Nose measurement at the time of injury was 3.5 mm (SD 1.0) and was 3.5 mm (SD 0.8) at the time of final follow-up (P = 0.47). CONCLUSIONS: No patients with stable OTA/AO 44-B1 fractures proceeded to surgery for loss of tibiotalar reduction or any other cause. Radiographic relationships were conserved during the follow-up, and serial radiographs may not be needed when managing these patients. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Geographic variations in the cost of spine surgery.

STUDY DESIGN: Retrospective review. OBJECTIVE: To define the geographic variation in costs of anterior cervical discectomy and fusion (ACDF) and posterolateral fusion (PLF). SUMMARY OF BACKGROUND DATA: ACDF and lumbar PLF are common procedures that are used in the treatment of spinal pathologies. To optimize value, both the benefits and costs of an intervention must be quantified. Data on costs are scarce in comparison with data on total charges. This study aims at defining the costs of ACDF and PLF and describing the geographic variation within the United States. METHODS: Medicare Provider Utilization and Payment data were used to investigate the costs associated with ACDF, PLF, and total knee arthroplasty (TKA). Average total costs of the procedures were compared by state and geographic region. RESULTS: Combined professional and facility costs for a single-level ACDF had a national mean of $13,899. Total costs for a single-level PLF had a mean of $25,858. Total costs for a primary TKA had a national mean of $13,039. The cost increased to an average of $22,138 for TKA with major comorbidities. Analysis of geographic trends showed statistically significant differences in total costs of PLF, TKA, and TKA, with major complications or comorbidities between geographic regions (P < 0.01 for all). CONCLUSION: Three of the 4 procedures (PLF, TKA, and TKA with major complications or comorbidities) showed statistically significant variation in cost between geographic regions. The Midwest provided the lowest cost for all procedures. Similar geographic trends in the cost of spinal fusions and TKAs suggest that these trends may not be limited to spine-related procedures. Surgical costs were found to correlate with cost of living but were not associated with the population of the state. These data shed light on the actual cost of common surgical procedures throughout the United States and will allow further progress toward the development of cost-effective, value-driven care. LEVEL OF EVIDENCE: 3.

Provoked exercise desaturation in patent foramen ovale and impact of percutaneous closure.

OBJECTIVES: This study was designed to assess the prevalence of provoked exercise desaturation (PED) in patients with patent foramen ovale (PFO) referred for cardiovascular evaluation and to evaluate the impact of PFO closure. BACKGROUND: Platypnea orthodeoxia syndrome is a rare, mechanistically obscure consequence of PFO that results in oxygen desaturation during postural changes. In our clinical experience, however, it is far less common than desaturation during exercise. METHODS: This was a single-center prospective study of 50 patients with newly diagnosed PFO. Each patient underwent standardized assessment for arterial oxygen saturation with pulse oximetry during postural changes and stair climbing exercise. Provoked exercise desaturation was defined as a desaturation of at least 8% from baseline to <90%. All patients who underwent closure were reevaluated 3 months after the procedure. Those with baseline PED were similarly reassessed for desaturation at follow-up. RESULTS: Mean age of the cohort was 46 ± 17 years, 74% were female, 30% had migraines, and 48% had experienced a cerebrovascular event. Seventeen patients (34%) demonstrated PED. Provoked exercise desaturation patients seemed demographically similar to non-PED patients. Ten PED patients underwent PFO closure (2 surgical, and 8 percutaneous). Drop in oxygen saturation was improved by an average of 10.1 ± 4.2% after closure (p < 0.001), and New York Heart Association functional class improved by a median of 1.5 classes (interquartile range: 0.75 to 2.00, p = 0.008). CONCLUSIONS: One-third of patients referred for assessment of PFO experience oxygen desaturation during stair exercise. Closure of PFO seems to ameliorate this phenomenon and improve functional status.

An ex-ovo chicken embryo culture system suitable for imaging and microsurgery applications.

Understanding the relationships between genetic and microenvironmental factors that drive normal and malformed embryonic development is fundamental for discovering new therapeutic strategies. Advancements in imaging technology have enabled quantitative investigation of the organization and maturing of the body plan, but later stage embryonic morphogenesis is less clear. Chicken embryos are an attractive vertebrate animal model system for this application because of its ease of culture and surgical manipulation. Early embryos can be cultured for a short time on filter paper rings, which enables complete optical access for cell patterning and fate studies. Studying advanced developmental processes such as cardiac morphogenesis are traditionally performed through a window of the eggshell, but this technique limits optical access due to window size. We previously developed a simple method to culture whole embryos ex-ovo on hexagonal weigh boats for up to 10 days, which enabled high resolution imaging via ultrasonography. These cultures were difficult to transport, limiting the types of imaging tools available for live experiments. We here present an improved shell-less culture system with a cost-effective, portable environmental chamber. Eggs were cracked onto a hammock created by a polyurethane membrane (cling wrap) affixed circumferentially to a plastic cup partially filled with sterile water. The dimensions of the circumference and depth of the hammock were both critical to maintain surface tension, while the mechanics of the hammock and water beneath helped dampen vibrations induced by transportation. A small footprint circulating water bath was also developed to enable continuous temperature control during experimentation. We demonstrate the ability to culture embryos in this way for at least 14 days without morphogenic defect or delay and employ this system in several microsurgical and imaging applications.

Two-photon microscopy-guided femtosecond-laser photoablation of avian cardiogenesis: noninvasive creation of localized heart defects.

Embryonic heart formation is driven by complex feedback between genetic and hemodynamic stimuli. Clinical congenital heart defects (CHD), however, often manifest as localized microtissue malformations with no underlying genetic mutation, suggesting that altered hemodynamics during embryonic development may play a role. An investigation of this relationship has been impaired by a lack of experimental tools that can create locally targeted cardiac perturbations. Here we have developed noninvasive optical techniques that can modulate avian cardiogenesis to dissect relationships between alterations in mechanical signaling and CHD. We used two-photon excited fluorescence microscopy to monitor cushion and ventricular dynamics and femtosecond pulsed laser photoablation to target micrometer-sized volumes inside the beating chick hearts. We selectively photoablated a small (∼100 µm radius) region of the superior atrioventricular (AV) cushion in Hamburger-Hamilton 24 chick embryos. We quantified via ultrasound that the disruption causes AV regurgitation, which resulted in a venous pooling of blood and severe arterial constriction. At 48 h postablation, quantitative X-ray microcomputed tomography imaging demonstrated stunted ventricular growth and pronounced left atrial dilation. A histological analysis demonstrated that the laser ablation produced defects localized to the superior AV cushion: a small quasispherical region of cushion tissue was completely obliterated, and the area adjacent to the myocardial wall was less cellularized. Both cushions and myocardium were significantly smaller than sham-operated controls. Our results highlight that two-photon excited fluorescence coupled with femtosecond pulsed laser photoablation should be considered a powerful tool for studying hemodynamic signaling in cardiac morphogenesis through the creation of localized microscale defects that may mimic clinical CHD.