Incidence and characteristics of hospitalization for proximal aortic surgery for acute syndromes and for aneurysms in the USA from 2005 to 2014.

OBJECTIVES: The effectiveness of proximal thoracic aortic aneurysm (TAA) surgery in preventing acute aortic syndromes, such as dissection and rupture, is unknown at the populational level. This study evaluated trends in acute aortic syndrome operation incidence relative to proximal aortic surgical volume in the USA. METHODS: A retrospective analysis of the National Inpatient Sample in 2005-2014 was performed. Acute aortic syndrome and TAA were identified with International Classification of Diseases, 9th edition diagnosis codes. Proximal aortic surgery was defined as the diagnosis of acute aortic syndrome or TAA with an aortic procedure and either cardioplegia, cardiopulmonary bypass or other cardiac operation. Annual rates of acute aortic syndrome surgery and proximal thoracic aneurysm surgery were adjusted for US population. Trends were evaluated using linear regression. RESULTS: We identified 38 442 operations for acute aortic diagnoses and 74 953 operations for TAAs. Case volume for acute aortic syndromes increased from 0.93 to 1.63 per 100 000 (P = 0.001), and aneurysm surgery increased from 1.75 to 3.19 per 100 000 (P < 0.001). Patient and hospital characteristics differed between acute aortic and aneurysm operations, with black patients being most notably underrepresented in the aneurysm population (4.9% vs 17.0%, P < 0.001). CONCLUSIONS: Acute aortic syndrome operative volume increased from 2005 to 2014 despite increasing rates of proximal aortic aneurysm surgery. Patient characteristic discrepancies were observed between the 2 groups of hospitalizations, highlighting the need for continued efforts to minimize sociodemographic disparities.

Enhancing Selectivity and Kinetics in Oxidative Photocyclization by Supramolecular Control.

Photochemical reactions typically proceed via multiple reaction pathways, yielding a variety of isomers and products. Enhancing the selectivity is challenging. Now, the potential of supramolecular control for oxidative photocyclization of a tetraarylethylene, containing a stereogenic -C=C- bond, is demonstrated. In solution, this photochemical reaction produces three constitutional isomers (substituted phenanthrenes), with slow kinetics. When the reactant is assembled into a crystalline framework, only one product forms with accelerated kinetics. Key to this selectivity enhancement is the integration into a surface grown metal-organic framework (SURMOF); the dramatic gain in selectivity is ascribed to the hindrance of the rotational freedom of the -C=C- double bond. The structure of the MOF is key; the corresponding reaction in the solid does not result in such a high increase in selectivity. A striking change of luminescence properties after photocyclization is observed.

Variables Associated with Chondral and Meniscal Injuries in Anterior Cruciate Ligament Surgery.

This article aims to evaluate factors associated with chondral and meniscal lesions in primary and revision anterior cruciate ligament (ACL) reconstructions. ACL reconstructions from 2001 to 2008 at a single institution were retrospectively analyzed. Logistic regression was used to estimate the association between chondral and meniscal injuries and age, gender, tear chronicity, additional ligamentous injuries, sport type, and participation level. Of the 3,040 ACL reconstructions analyzed, 90.4% were primary reconstructions and 9.6% were revisions. Meniscal injuries were significantly lower in the revision group (44.0 vs. 51.9%; p = 0.01), while chondral injuries were significantly higher in the revision group (39.9 vs. 24.0%; p < 0.0001). Inspection of the small subgroup (n = 85) receiving both primary and revision ACL surgery at our center indicated that meniscal injuries at revision were evenly split between menisci with and without previous repairs, whereas the vast majority of Grade III and IV chondral lesions were new. More patients presented for surgery later in the revision group than in the primary group (56.5 vs. 35.3%; p < 0.0001). Male gender, primary reconstruction, and short interval (less than 2 weeks) between injury and surgery were associated with increased likelihood of meniscus tear. Age (greater than 22 years) and long interval (greater than 6 weeks) between injury to surgery and higher sport activity level were associated with chondral lesions. Revision ACL reconstructions are associated with a higher proportion of chondral lesions and a lower proportion of meniscal tears. Early primary and revision ACL construction is recommended to reduce the probability of chondral lesions.

The effects of extra-articular starting point and transtibial femoral drilling on the intra-articular aperture of the tibial tunnel in ACL reconstruction.

BACKGROUND: The recent emphasis on more horizontal femoral tunnel placement for single-bundle anterior cruciate ligament (ACL) reconstructions requires placing a femoral tunnel lower on the lateral wall of the notch. Some surgeons have advocated moving the starting point of the tibial tunnel farther medial to achieve this more horizontal tunnel. PURPOSE: To compare tibial tunnel aperture changes with transtibial femoral tunnel drilling. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty match-paired cadaveric knees (10 specimens) were randomized into 2 groups with equal right and left knee distribution. Ten of the knees underwent tibial tunnel drilling from a medial starting point (group 1), and the corresponding opposite knee of each cadaveric specimen had the tibial tunnel drilled from a central starting point (group 2). Computerized tomography (CT) with thin slices and 3-dimensional reconstruction was used to obtain the dimensions of the apertures, area of the apertures, angles of the tunnels, and location of the starting point and ending point of the tunnels. We also determined the location of the femoral tunnels in the notch for each of the groups. The 10 knees with medial starting points underwent transtibial femoral tunnel drilling and were restudied with CT to evaluate changes in tibial tunnel characteristics. The 10 knees with central starting points underwent femoral drilling from an anteromedial arthroscopic portal. RESULTS: Central tibial tunnels were slightly larger than medial tibial tunnels before femoral drilling (106.3 mm(3) vs 92.4 mm(3)). After femoral drilling through the medial tunnels, the apertures were larger than the central tibial apertures (118.6 mm(3) vs 106.3 mm(3)). Medial tibial tunnels resulted in an intra-articular aperture that was farther from the tibial tubercle (43.1 mm vs 16.3 mm), farther from the medial tibial plateau (38.3 mm vs 32.2 mm), and more acute in the coronal plane (50.4 degrees vs 79.3 degrees ). Medial tibial tunnels resulted in an intra-articular aperture that was closer to the anterior edge of the tibia (22.6 mm vs 29.6 mm) but with a less acute sagittal plane angle (82.5 degrees vs 54.5 degrees ). The average clock-face measurement on the femur was 10:40 (+/-14 minutes) for the medial starting point and 10:14 (+/-14 minutes) for the central starting point (drilled from an anteromedial arthroscopic portal) (P = .0016). CONCLUSION: We observed significantly increased tibial aperture size and shape after transtibial femoral drilling with a medial tibial starting point. Medial tibial tunnels, compared with more central tunnels, resulted in a more acute tibial tunnel in the coronal plane and less acute tibial tunnels relative to the sagittal plane. Medial tibial tunnels started farther from the tibial tubercle but ended farther from the medial joint line and closer to the anterior edge of the tibia in comparison to central tunnels Clinical Relevance Femoral tunnel placements may be best accomplished using a technique other than transtibial drilling through a medial tibial tunnel. Tibial tunnel angle, intra-articular position, and femoral tunnel placement are affected by the choice of extra-articular starting position.

Anterior cruciate ligament insertions on the tibia and femur and their relationships to critical bony landmarks using high-resolution volume-rendering computed tomography.

BACKGROUND: Controversy exists regarding the locations of the anterior cruciate ligament insertions on the femur and tibia and visualization of these insertions during surgical reconstruction. HYPOTHESIS: Anatomical insertions of the anterior cruciate ligament have relationships to bony landmarks of the tibia and femur. STUDY DESIGN: Descriptive laboratory study. METHODS: Eight cadaveric knees were scanned by computed tomography, reconstructed 3-dimensionally, and examined from simulated arthroscopic, sagittal, and axial perspectives. Volume-rendering software was used to document the relationship of the anterior cruciate ligament to the bony anatomy. RESULTS: A bony ridge (Resident's Ridge) at the anterior border of the anterior cruciate ligament was readily noted on the medial wall of the lateral femoral condyle. Superiorly, anterior cruciate ligament fibers inserted up to the roof of the notch and to 3 to 3.5 mm of the articular surface posteriorly and inferiorly. The anterior cruciate ligament inserted into a fovea anterior to the tibial eminence. Posteriorly, anterior cruciate ligament fibers inserted up to a ridge between the medial and lateral intercondylar tubercles. Medially, anterior cruciate ligament fibers inserted onto the ridge at the lateral border of the medial tibial condyle. There was no distinct anterior or lateral bony border with anterior cruciate ligament fibers blending into the anterior horn of the lateral meniscus. CONCLUSION: The anterior border of the femoral anterior cruciate ligament origin is Resident's Ridge. The ridge between the medial and lateral intercondylar tubercles at the base of the tibial eminence is the posterior margin of the anterior cruciate ligament on the tibia. CLINICAL RELEVANCE: Bony landmarks can be used to aid in anatomical anterior cruciate ligament reconstruction.

Allograft reconstruction for massive, irreparable rotator cuff tears.

BACKGROUND: There is currently no widely accepted treatment for massive, irreparable rotator cuff tears. HYPOTHESIS: Allograft reconstruction to span the remaining defect in massive, irreparable rotator cuff tears will lead to increased functional results and will demonstrate healing of the allograft on follow-up magnetic resonance imaging studies. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 1989 and 2003, 32 patients underwent allograft reconstruction of massive rotator cuff tears. University of California, Los Angeles shoulder scores were compared preoperatively and postoperatively and analyzed using paired Student t tests. In addition, 15 patients underwent postoperative magnetic resonance imaging to evaluate the structural integrity of the allograft reconstruction at the greater tuberosity insertion. RESULTS: Of 32 patients, 28 were available for review at a mean follow-up of 31.3 months; 23 of the 28 patients were satisfied with their outcome. There was 1 postoperative infection and 1 acute allograft rejection. The mean University of California, Los Angeles score increased from 12.1 preoperatively to 26.1 postoperatively (P < .001). All 15 patients evaluated with postoperative magnetic resonance imaging arthrograms demonstrated complete radiographic failure of the allograft rotator cuff reconstruction. Despite radiographic failure, the mean University of California, Los Angeles score increased from 13.2 preoperatively to 28.3 postoperatively in this subset of patients. CONCLUSION: The functional results of this reconstruction method are similar to those reported for debridement and subacromial decompression alone and are satisfactory, despite magnetic resonance imaging arthrogram evaluation demonstrating failure of the structural integrity of the allograft. Allograft reconstruction carries increased risk of infection and rejection and is technically more difficult than other less expensive treatment options with similar functional results. Therefore, we do not recommend allograft reconstruction of massive and otherwise irreparable rotator cuff tears.

Anatomic endoscopic anterior cruciate ligament reconstruction with patella tendon autograft.

Current tibial endoscopic ACL reconstruction techniques provide functional stability, but fall short of the ultimate goal of ACL reconstruction, to restore normal knee kinematics. Vertical graft placement results in restoration of normal anteroposterior stability with a negative Lachman exam, but may not produce a stable knee in rotation, noted by a positive pivot shift. The Clancy anatomic endoscopic ACL reconstruction technique utilizes flexible reamers to achieve anatomic graft placement to more closely reproduce normal knee function. The overall results of arthroscopic anatomic endoscopic ACL reconstruction are essentially the same as we have reported using our previous open and rear-entry, two-incision techniques for anatomic graft placement. The long-term benefits of a more physiologic single incision endoscopic ACL reconstruction are not yet determined; however, short-term results are encouraging.