The use of subchondral bone topography to approximate the center of rotation of the elbow joint in dogs.

OBJECTIVES: The aim of this study was to compare the approximate center of rotation in normal and diseased elbows in dogs. STUDY DESIGN: Cross-sectional study SAMPLE POPULATION: Computer tomography scans of nine dogs with unilateral fragmented medial coronoid process (FMCP). METHODS: A board certified radiologist confirmed that each dog had unilateral FMCP, and a normal contralateral elbow. Digital 3D models of all elbow joints were uploaded into a surgical planning software package. Four axes approximating the center of rotation (COR) of elbow joints were generated using five geometric shapes based on subchondral topography of the humeral condyle radius and ulna. Images showing the locations where axes exited the medial and lateral cortex of the humeral condyle were captured and imported into a second software package, for measurement of distances between exit points and the origin of a system of axes. RESULTS: In normal joints 20/27 (74%) axes exited the medial cortex, and 25/27 (93%) axes exited the lateral cortex cranial and distal to the medial and lateral epicondyles, respectively. In diseased joints 22/27 (81%) axes exited medial cortex and 19/27 (70%) axes exited the lateral cortex, caudal and distal to the medial and lateral epicondyles, respectively. CONCLUSION: Based on CT- derived geometry, the COR of elbow affected with FMCP was generally more caudal than normal. CLINICAL SIGNIFICANCE: External landmarks approximating the location of the elbow COR are provided, and while not validated, may assist in planning, creation, and assessment of procedures for FMCP.

The Effect of Increasing Tibial Tuberosity Advancement and Quadriceps Muscle Force on Cranial Translation of the Tibia in the Cranial Cruciate Deficient Stifle Joint in Dogs.

Background: Cranial cruciate ligament (CCL) disease is a well-known pathology that generates both rotational and translational instability of the stifle joint that leads to osteoarthritis in dogs. Tibial tuberosity advancement (TTA) is a common surgical technique used to dynamically neutralize the tibiofemoral shear forces to achieve stifle joint stability. However, significant persistent instability has been documented in clinical cases. The purpose of this study was to evaluate the effect of increasing quadriceps load, increasing tibial tuberosity advancement, and increasing joint flexion angle on the cranial translation of the tibia relative to the femur in the cranial cruciate ligament deficient stifle joint. Methods and Results: Six cadaveric hind limbs were collected from six healthy mixed breed dogs of medium build and prepared for biomechanical testing. The specimen was placed into a custom-made joint testing machine, and translation of the tibia relative to the femur was measured at stifle angles of 135°, 120°, and 105°. Cranial tibial thrust was generated by applying a vertical load to the metatarsal pad and the quadriceps muscle was simulated with loads of 0, 5, and 10 kg applied to the patella via a system of weights and pulleys. All specimens were tested with the CCL intact and cut, both of which served as controls. The tibial tuberosity was then advanced using both 6 mm and 9 mm cages, and the specimen was tested using the identical technique. Each specimen was loaded to failure by increasing the load applied to the pes until the sudden marked cranial translation of the tibia. Tibial tuberosity advancement with an applied quadriceps load was successful in limiting cranial tibial translation in 54/62 tests. Under similar loading conditions, TTA failed to limit cranial translation in 8 tests. The failures occurred at all angles of flexion examined. In the cases that failed cranial translation could be limited by either increasing the quadriceps load or increasing the amount of tibial tuberosity advancement. Conclusion: This study showed that TTA with an applied quadriceps load is effective at decreasing cranial tibial translation at functional joint angles.

Directed, Elliptic, and Higher Order Flow Harmonics of Protons, Deuterons, and Tritons in Au+Au Collisions at sqrt[s_{NN}]=2.4 GeV.

Flow coefficients v_{n} of the orders n=1-6 are measured with the High-Acceptance DiElectron Spectrometer (HADES) at GSI for protons, deuterons, and tritons as a function of centrality, transverse momentum, and rapidity in Au+Au collisions at sqrt[s_{NN}]=2.4 GeV. Combining the information from the flow coefficients of all orders allows us to construct for the first time, at collision energies of a few GeV, a multidifferential picture of the angular emission pattern of these particles. It reflects the complicated interplay between the effect of the central fireball pressure on the emission of particles and their subsequent interaction with spectator matter. The high precision information on higher order flow coefficients is a major step forward in constraining the equation of state of dense baryonic matter.

Strong Absorption of Hadrons with Hidden and Open Strangeness in Nuclear Matter.

We present the first observation of K^{-} and ϕ absorption within nuclear matter by means of π^{-}-induced reactions on C and W targets at an incident beam momentum of 1.7 GeV/c studied with HADES at SIS18/GSI. The double ratio (K^{-}/K^{+})_{W}/(K^{-}/K^{+})_{C} is found to be 0.319±0.009(stat)_{-0.012}^{+0.014}(syst) indicating a larger absorption of K^{-} in heavier targets as compared to lighter ones. The measured ϕ/K^{-} ratios in π^{-}+C and π^{-}+W reactions within the HADES acceptance are found to be equal to 0.55±0.04(stat)_{-0.07}^{+0.06}(syst) and to 0.63±0.06(stat)_{-0.11}^{+0.11}(syst), respectively. The similar ratios measured in the two different reactions demonstrate for the first time experimentally that the dynamics of the ϕ meson in nuclear medium is strongly coupled to the K^{-} dynamics. The large difference in the ϕ production off C and W nuclei is discussed in terms of a strong ϕN in-medium coupling. These results are relevant for the description of heavy-ion collisions and the structure of neutron stars.

Subthreshold Ξ

Results on the production of the double strange cascade hyperon Ξ^{-} are reported for collisions of p(3.5 GeV)+Nb, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18 at GSI Helmholtzzentrum for Heavy-Ion Research, Darmstadt. For the first time, subthreshold Ξ^{-} production is observed in proton-nucleus interactions. Assuming a Ξ^{-} phase-space distribution similar to that of Λ hyperons, the production probability amounts to P_{Ξ^{-}}=[2.0±0.4(stat)±0.3(norm)±0.6(syst)]×10^{-4} resulting in a Ξ^{-}/(Λ+Σ^{0}) ratio of P_{Ξ^{-}}/P_{Λ+Σ^{0}}=[1.2±0.3(stat)±0.4(syst)]×10^{-2}. Available model predictions are significantly lower than the measured Ξ^{-} yield.

An unusual presentation of uterine didelphys and obstructed hemivagina.

BACKGROUND: Congenital disorders of the genitourinary system can be unpredictable. There are both medical and surgical interventions that can help manage symptoms. CASE: A 10-year-old girl was evaluated 6 months post-menarche with dysuria and pelvic pain. Her symptoms were not relieved with menstrual suppression. Evaluation revealed a probable ectopic ureter versus ureterocele and uterine didelphys with suspicion for obstructed hemivagina and hematocolpos. Surgical exploration revealed an obstructed hemivagina with a high vaginal septum. When resection failed, she ultimately underwent a robot-assisted hemihysterectomy, with resolution of her symptoms. SUMMARY AND CONCLUSIONS: In this case presentation, a surgical approach was necessary to adequately make a diagnosis. When vaginal septum resection failed, robot-assisted laparoscopic hemi-hysterectomy and resection of a vaginal pouch led to symptom resolution in this pediatric patient with a complex anomaly.

Access to conservative surgical therapy for adolescents with benign ovarian masses.

OBJECTIVE: To perform a population-based analysis to determine possible factors associated with use of laparoscopy and ovarian-conserving cystectomy. METHODS: Women and girls aged 18 years or younger with benign ovarian masses who underwent surgery from 2000 to 2010 and were recorded in a commercial database were analyzed. Patients were classified based on the surgical approach (open compared with laparoscopy) and procedure (oophorectomy compared with cystectomy). Use of laparoscopy and performance of cystectomy were characterized using multivariable logistic regression models accounting for patient, surgeon, and hospital characteristics. RESULTS: A total of 2,126 patients, including 1,425 (67.0%) who underwent laparotomy and 701 (33.0%) who had laparoscopy, were identified. Laparoscopy increased from 32.1% in 2000 to 57.9% by 2010. In a multivariable model, African American women and girls (odds ratio [OR] 0.49, 95% confidence interval [CI] 0.37-0.65) and patients in the Northeast (OR 0.65, 95% CI 0.46-0.94) were less likely to undergo laparoscopy, whereas treatment at a high-volume hospital (OR 1.35, 95% CI 1.04-1.75) was associated with use of laparoscopy. Cystectomy was performed in 57.1% in 2000 and increased to 61.4% in 2010. The only significant predictors of cystectomy were age and the specialty of the treating physician; patients aged 13-16 years (OR 1.34, 95% CI 1.03-1.75) were more likely to undergo cystectomy than were younger patients, whereas patients treated by surgeons (OR 0.51, 95% CI 0.38-0.68) were less likely to undergo cystectomy than were those treated by gynecologists. CONCLUSION: The treatment of adolescents with benign ovarian masses is highly variable. In addition to patient characteristics, both physician and hospital factors strongly influenced treatment. LEVEL OF EVIDENCE: II.

Thyroid cancer in pregnancy.

OBJECTIVE: To compare stage at diagnosis, treatment and survival among pregnant women with thyroid cancer to non-pregnant women with thyroid cancer, and to assess the impact of treatment on maternal and perinatal outcomes. METHODS: A database containing maternal and newborn discharge records linked to the California Cancer Registry was queried to obtain information on all thyroid cancers from 1991-1999. Women with thyroid cancer occurring during pregnancy were compared to age-matched non-pregnant women with thyroid cancer. RESULTS: 595 cases of thyroid cancers were identified (129 antepartum and 466 postpartum). About 64% of thyroid cancers were diagnosed at stage 2 among pregnant women versus 58% among non-pregnant controls. The odds of thyroid cancer were 1.5 times higher among Asian/Pacific Islanders than among Non-Hispanic White women. Pregnancy had no significant effect on mortality after diagnosis of thyroid cancer. Thyroidectomy during pregnancy was not associated with adverse maternal or neonatal outcomes. CONCLUSIONS: Thyroid cancer discovered during or after pregnancy does not appear to have a significant impact on the prognosis of the disease.