Trait decoupling promotes evolutionary diversification of the trophic and acoustic system of damselfishes.

Trait decoupling, wherein evolutionary release of constraints permits specialization of formerly integrated structures, represents a major conceptual framework for interpreting patterns of organismal diversity. However, few empirical tests of this hypothesis exist. A central prediction, that the tempo of morphological evolution and ecological diversification should increase following decoupling events, remains inadequately tested. In damselfishes (Pomacentridae), a ceratomandibular ligament links the hyoid bar and lower jaws, coupling two main morphofunctional units directly involved in both feeding and sound production. Here, we test the decoupling hypothesis by examining the evolutionary consequences of the loss of the ceratomandibular ligament in multiple damselfish lineages. As predicted, we find that rates of morphological evolution of trophic structures increased following the loss of the ligament. However, this increase in evolutionary rate is not associated with an increase in trophic breadth, but rather with morphofunctional specialization for the capture of zooplanktonic prey. Lineages lacking the ceratomandibular ligament also shows different acoustic signals (i.e. higher variation of pulse periods) from others, resulting in an increase of the acoustic diversity across the family. Our results support the idea that trait decoupling can increase morphological and behavioural diversity through increased specialization rather than the generation of novel ecotypes.

Influence of CYP2D6 activity on pre-emptive analgesia by the N-methyl-D-aspartate antagonist dextromethorphan in a randomized controlled trial of acute pain.

BACKGROUND: There is some evidence that dextromethorphan (DM) is effective as a pre-emptive analgesic agent.  DM is mainly metabolized to dextrorphan (DOR) by CYP2D6 whose activity can be inhibited by pharmacologic intervention. OBJECTIVES: To investigate the efficacy of DM as a pre-emptive analgesic agent and describe the population pharmacokinetics in the presence of normal and poor CYP2D6 metabolism in acute post-operative pain. STUDY DESIGN: Double blind, randomized, placebo-controlled trial SETTING: Post-surgical analgesic consumption after knee ligament surgery, a setting of acute pain. METHODS: Forty patients were randomized to a single oral dose of 50 mg quinidine or placebo, administered 12 hours before 50 mg DM. Patients were genotyped for the major CYP2D6 and ABCB1 variants and phenotyped for CYP2D6 using urine DM/DOR metabolic ratios and blood samples for population pharmacokinetic modeling. RESULTS: Quinidine was effective in inhibiting CYP2D6 activity, with 2-fold reduction of DM to DOR biotransformation clearance, prolonged DM half-life, and increased DM systemic availability. Patients in the quinidine group required significantly less often NSAIDs than patients in the placebo group (35.3% vs. 75.0%, P = 0.022). The odds ratio for NSAID consumption in the placebo vs. quinidine group was 5.5 (95% confidence interval (CI) 1.3 - 22.7) at 48 hours after surgery. LIMITATIONS: While this study shows an impact of DM on pre-emptive analgesia and is mechanistically interesting, the findings need to be confirmed in larger trials. CONCLUSION: CYP2D6 inhibition by quinidine influenced the pre-emptive analgesic effectiveness of DM confirming that CYP2D6 phenotypic switch increases the neuromodulatory effect of oral dextromethorphan.

Arthro-IRM du poignet à 3-T en traction axiale : impact sur la caractérisation des lésions ligamentaires.

Objectifs: Déterminer l'impact de la traction axiale en arthro-IRM du poignet sur la largeur des espaces interosseux et la caractérisation des lésions ligamentairesintrinsèques du carpe. Matériels et méthodes: Etude prospective incluant 34 patients entre septembre et décembre 2010. Arthro-IRM du poignet réalisées sur une machine 3-Tesla et incluant des séquencescoronales isotropiques haute résolution en pondération T1-VIBE avec suppression de graisse, sans et avec traction axiale (4kg). Lecture consensuelle par 2radiologues avec mesure des espaces scapho-lunaire, luno-triquétral et ulna-TFC, sans et avec traction. Evaluation semi-quantitative des déchiruresligamentaires: 0=absente, 1=partielle, 2=transfixiante avec moignon, 3=transfixiante sans moignon. Résultats: Augmentation significative, en traction axiale, des espaces interosseux scapho-lunaire (Delta=0.21mm, p=0.0016) et luno-triquétral (Delta=0.17mm, p=0.0002)ainsi que de l'espace ulna-TFC (Delta=0.17, p=0.0071). Meilleure caractérisation des lésions dans 5 cas, avec une amélioration significative pour la portioncentrale du ligament scapho-lunaire (p=0.0313). Conclusion: L'arthro-IRM du poignet à 3-Tesla en traction axiale augmente significativement la largeur des espaces scapho -lunaire, luno-triquétral et ulna-TFC et améliore lacaractérisation des lésions de la portion centrale du ligament scapho-lunaire.

Reduction in range of cervical motion on serial long-term follow-up in patients undergoing oblique corpectomy for cervical spondylotic myelopathy.

PURPOSE: To determine whether motion preservation following oblique cervical corpectomy (OCC) for cervical spondylotic myelopathy (CSM) persists with serial follow-up. METHODS: We included 28 patients with preoperative and at least two serial follow-up neutral and dynamic cervical spine radiographs who underwent OCC for CSM. Patients with an ossified posterior longitudinal ligament (OPLL) were excluded. Changes in sagittal curvature, segmental and whole spine range of motion (ROM) were measured. Nathan's system graded anterior osteophyte formation. Neurological function was measured by Nurick's grade and modified Japanese Orthopedic Association (JOA) scores. RESULTS: The majority (23 patients) had a single or 2-level corpectomy. The average duration of follow-up was 45 months. The Nurick's grade and the JOA scores showed statistically significant improvements after surgery (p < 0.001). 17% of patients with preoperative lordotic spines had a loss of lordosis at last follow-up, but with no clinical worsening. 77% of the whole spine ROM and 62% of segmental ROM was preserved at last follow-up. The whole spine and segmental ROM decreased by 11.2° and 10.9°, respectively (p ≤ 0.001). Patients with a greater range of segmental movement preoperatively had a statistically greater range of movement at follow-up. The analysis of serial radiographs indicated that the range of movement of the whole spine and the range of movement at the segmental spine levels significantly reduced during the follow-up period. Nathan's grade showed increase in osteophytosis in more than two-thirds of the patients (p ≤ 0.01). The whole spine range of movement at follow-up significantly correlated with Nathan's grade. CONCLUSIONS: Although the OCC preserves segmental and whole spine ROM, serial measurements show a progressive decrease in ROM albeit without clinical worsening. The reduction in this ROM is probably related to degenerative ossification of spinal ligaments.

Bilateral extraperitoneal uterosacral vaginal vault suspension: a 2-year follow-up longitudinal case series of 123 patients.

INTRODUCTION AND HYPOTHESIS: The objective of this study is to assess anatomical and functional results of the extraperitoneal uterosacral ligament suspension (USL) in women with post-hysterectomy vaginal vault prolapse. METHODS: One hundred and twenty-three consecutive women were included. Concurrent procedures were anterior colporraphy with fascial repair (20%) and mesh reinforcement (49%), posterior colporraphy with fascial repair (38%) and mesh reinforcement (56%) and a sling procedure (29%). Women were assessed using Baden and Walker and pelvic organ prolapse quantification classification pre- and post-operatively. RESULTS: One hundred and ten patients (89%) were available for follow-up. Mean follow-up was 2 years. Objective success rate regarding the vaginal cuff is 95.4%. Global anatomical success rate was 85.5%. Urinary, coital and bowel symptoms were improved following surgery. Mesh exposure rate was 19.3%, with all cases managed conservatively or with minor interventions. CONCLUSION: Bilateral extraperitoneal USL is an effective operation to restore apical support with low morbidity, which avoids potential risks associated with opening the peritoneal cavity.

Transolecranon anterior fracture dislocation.

Between January 1996 and July 2003, 93 consecutive patients operated on with a diagnosis of olecranon fractures were identified from our trauma unit files. Fourteen transolecranon fracture-dislocations were found after a retrospective X-radiographic evaluation. Eight patients were women and six were men, with a mean age of 54 years. There were 4 noncomminuted olecranon fractures, treated with K-wires and single tension-band wiring. The remaining 10 fractures were complex fractures, treated in 3 cases with multiple K-wires and single tension-band wiring, in 2 by use of one-third tubular plates, in 1 with a 3.5-mm dynamic compression plate, and in the remaining 4 with 3.5-mm reconstruction plates. Ligament repair was not performed in any case. Three patients needed reoperation because of early failure of primary fixation. Patients were reviewed at a mean follow-up of 3.6 years. Two reported difficulties in daily activities, none with any symptoms of elbow instability. According to the Broberg and Morrey score, 4 patients had excellent results, 6 had good results, 2 had fair results, and 2 had poor results. Four patients showed signs of degenerative arthritis on the radiographs obtained at follow-up. We conclude that transolecranon fracture-dislocation is an underreported and misdiagnosed injury. Various fixation techniques can restore the anatomic relationships and contour of the trochlear notch; the imperative goal is to obtain a good stable primary fixation and allow early active mobilization.

Ligamentous and tendinous anatomy of the intermetacarpal and common carpometacarpal joints: evaluation with MR imaging and MR arthrography.

PURPOSE: The purpose of this work was to demonstrate the normal ligamentous and tendinous anatomy of the intermetacarpal (IMC) and common carpometacarpal (CCMC) joints with MRI and MR arthrography. METHOD: MR images of 22 wrists derived from fresh human cadavers were obtained before and after arthrography. The MR imaging features of the ligaments and tendons about the CCMC and IMC joints and the joints themselves were analyzed in a randomized fashion and correlated with those seen on anatomic sections. RESULTS: Six CCMC ligaments were visualized. The dorsal and palmar CCMC ligaments and the pisometacarpal ligament were best visualized in the sagittal plane. The radial and ulnar CCMC collateral ligaments and the capito-third metacarpal ligament were best visualized in the coronal plane. Three main IMC ligaments were observed: a dorsal and a palmar ligament and an interosseous ligament complex. All three ligaments were best visualized in the axial plane. Four tendinous insertions to the metacarpal bases were evident. CONCLUSION: The anatomy of the ligaments and tendinous insertions about the second to fifth IMC and the CCMC joints is well demonstrated by MR imaging and MR arthrography. MR arthrography does not significantly improve the visualization of these complex structures.

Pektinaattiligamenttidysplasia ja glaukooma labradorinnoutajalla

Summary: Pectinate ligament dysplasia and glaucoma in Labrador Retriever

Analysis of joint laxity after total ankle arthroplasty: cadaver study.

BACKGROUND: Clinical results of total ankle arthroplasty with early designs were disappointing. Recently-developed ankle prostheses have good mid-term results; however, limited information is available regarding effects of total ankle arthroplasty on ankle laxity. METHODS: Eight cadaveric lower extremities were tested with a custom device which enabled measurement of multi-axial forces, moments, and displacement during applied axial, shear, and rotational loading. Tests consisted of anterior-posterior and medial-lateral translation and internal-external rotation of the talus relative to the tibia during axial loads on the tibia simulating body weight (700 N) and an unloaded condition (5 N). Tests were performed in neutral, dorsiflexion, and plantarflexion. Laxity was determined for the intact ankle, and following insertion of an unconstrained total ankle implant, comparing load-displacement curve. FINDINGS: Laxity after total ankle arthroplasty did not approximate the normal ankle in most conditions tested. Displacement was significantly greater for total ankle arthroplasty in both posterior and lateral translation, and internal rotation, with 5 N axial loading, and anterior-posterior, medial-lateral translation, and internal-external rotation for 700 N axial loading. For the 700 N axial load condition, in the neutral ankle position, total anterior-posterior translation averaged 0.4 mm (SD 0.2 mm), but 6.0 mm (SD 1.5 mm) after total ankle arthroplasty (P<0.01). This study demonstrated more laxity in the replaced ankle than normal ankle for both unloaded and 700 N axially loaded conditions. INTERPRETATION: These data indicate the increased responsibility of the ligaments for ankle laxity after total ankle arthroplasty and suggest the importance of meticulous ligament reconstruction with total ankle arthroplasty operations.

Laparoscopic surgery for coeliac artery compression syndrome: current management and technical aspects.

Objectives: The study aims to assess the feasibility and midterm outcome of trans-peritoneal laparoscopy for coeliac artery compression syndrome (CACS).Design: Retrospective chart review involving four European vascular surgery departments and two surgical teams.Materials and methods: charts for patients who underwent laparoscopy for symptomatic CACS between December 2003 and November 2009 were reviewed. Preoperative computed tomography (CT) angiography and postoperative duplex scan and/or CT angiography were performed.Results: Eleven consecutive patients (nine women) with a median age of 52 years (interquartile range: 42.5-59 years) underwent trans-peritoneal laparoscopy for CACS. All patients had a history of postprandial abdominal pain; weight loss exceeded 10% of the body mass in eight cases. Preoperative CT angiography revealed coeliac trunk stenosis >70% in all cases. One patient had additional aortitis and inferior mesenteric artery occlusion, while another patient presented with an occluded superior mesenteric artery. Two conversions occurred (one difficult dissection and one aorto-hepatic bypass needed for incomplete release of CACS). The median blood loss was 195 ml (range: 50-900 ml) and median operative time was 80 min (interquartile range: 65-162.5 years). Symptoms improved immediately in 10/11 patients (no residual stenosis) while one remained unchanged despite a residual stenosis treated by a percutaneous angioplasty. Symptoms reappeared in one patient due to coeliac axis occlusion. The mean follow-up period was 35 +/- 23 months (range: 12-78 months).Conclusion: Our study demonstrates that trans-peritoneal laparoscopy for treating median arcuate ligament syndrome is safe and feasible. Additional patients and a longer follow-up are needed for long-term assessment of this laparoscopic technique. (C) 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Intrinsic coordinate system for the tibial plateau

Determination of the sub-chondral bone density, or more precisely the internal density spot, can be used to evaluate the capability of a knee to sustain normal kinematics. To use this technique as a mean of knee kinematics control, the position of the internal density spot must be determined in a reproducible way. This paper presents a definition of an intrinsic polar coordinate system, allowing to measure the position of the internal density spot of the tibial plateau. Tests of reproducibility gave good results and justify the use of this coordinate system for comparison of the internal density spot position between left and right paired knees.

Wide resection of the lateral malleolus and adjacent tibial, talar and calcanear bones with ankle fusion and allograft reconstruction for an osteosarcoma.

Introduction: Primary bone sarcomas around the ankle are rare. Due to the proximity of neurovascular structures and limited soft tissue reserves, limb salvage is often not possible. Case report: A 19 yo male presented with pain and a progressive swelling of his ankle. X-rays revealed cortical erosions and an extensive periosteal reaction (sunburst) of the distal fibula. MRI showed a large mass of the fibula invading adjacent soft tissue. The lesion appeared close to the ankle joint, but with the articular cartilage as a barrier and without joint effusion. Core-needle biopsy revealed a high-grade chondroblastic osteosarcoma. No metastases were detected. After presentation at our multidisciplinary sarcoma board, the patient was subjected to neo-adjuvant chemotherapy (AOST 03-331). Without any sign of intra-articular contamination of the ankle joint, surgical treatment consisted of wide resection of the lateral malleolus including a large skin patch, the distal third of the fibula, the lateral surfaces of the tibia and talus as well as the insertion of the lateral ligament on the calcaneus. The distal parts of the anterior, peroneal, and posterior muscular compartments were resected en bloc with the tumor. The defect was reconstructed with tibio-talar and talo-calcanear fusion, bony allograft and a plate. Soft-tissue coverage was achieved with a free fascio-cutaneous flap from the controlateral thigh. Histological analysis revealed clear margins and 50% of tumor necrosis. The oncologic treatment was completed with adjuvant chemotherapy. Conclusion: Wide resection and reconstruction of the lateral malleolus is technically demanding but possible in selected cases. Despite some important functional loss, limb salvage is superior to an amputation.

Biologically enhanced ACL reconstruction.

Biological integration of the tendon graft is a crucial prerequisite for successful ACL reconstruction. Histological studies showed that the human ACL remnants contain a cellular capacity for healing potential. The goal of this technical note is to describe an ACL reconstruction technique, using ACL remnants as a biological sleeve for the graft. In case of complete ACL rupture with a large remnant, the tibial tunnel was performed inside and through the ACL tibial stump by careful sequential drilling. Femoral tunnel placement was performed by an outside-in technique. The hamstring graft was kept attached to the tibia and routed through the ACL remnant to the femur. The aim of this technique is the preservation of the biological and mechanical properties of the ACL remnant. In order to preserve large remnants resulting in greater graft coverage, the best period to perform this reconstruction is during the first weeks after the injury.

Nonunion after fracture of the anterior tibial spine: case report and review of the literature.

Nonunion of anterior tibial spine of tibia in children is quite rare, but it could be associated with significant instability of the knee as it involves the fixation of anterior cruciate ligament. We report one case in which open reduction and internal fixation was carried out with good functional results. A literature review was performed to identify the cases reported of tibial eminence nonunion in children.

Histopathological evaluation of root canal filling materials for primary teeth

This study aimed to assess the response of apical and periapical tissues of dogs¿ teeth after root canal filling with different materials. Forty roots from dogs¿ premolars were prepared biomechanically and assigned to 4 groups filled with: Group I: commercial calcium hydroxide and polyethylene glycol-based paste (Calen®) thickened with zinc oxide; Group II: paste composed of iodoform, Rifocort® and camphorated amonochlorophenol; Group III: zinc oxide-eugenol cement; Group IV: sterile saline. After 30 days, the samples were subjected to histological processing. The histopathological findings revealed that in Groups I and IV the apical and periapical regions exhibited normal appearance, with large number of fibers and cells and no resorption of mineralized tissues. In Group II, mild inflammatory infiltrate and mild edema were observed, with discrete fibrogenesis and bone resorption. Group III showed altered periapical region and thickened periodontal ligament with presence of inflammatory cells and edema. It may be concluded that the Calen paste thickened with zinc oxide yielded the best tissue response, being the most indicated material for root canal filling of primary teeth with pulp vitality.