Anomalous Courses of the Palmar Cutaneous Branch of the Median Nerve in Relation to the Flexor Carpi Radialis Tendon for ORIF of Distal Radius Fractures.

Background: The purpose of this study was to prospectively document the incidence of variations in the course of palmar cutaneous branch of the median nerve (PCBMN) that may increase the risk of injury to the nerve during the flexor carpi radialis (FCR) approach. We hypothesize that the incidence of anomalous branching of the PCBMN around the FCR sheath will be approximately 5%. Methods: All cases that met inclusion criteria between November 2013 and March 2018 were included. The operating surgeon made the final decision for operative intervention using the FCR approach. Each surgeon performed the standard FCR approach to the distal radius. The branching location from the median nerve, the relationship to the FCR sheath, and the course of the PCBMN were recorded. Results: In total, 101 distal radius fractures were included. The average branching point of PCBMN was 5.2 cm from the distal wrist crease (range = 3.3-9.0). There were 26 anomalous branching patterns of PCBMN. Nineteen (18.8%) crossed volar, dorsal, or ran within the FCR sheath. Six PCBMN were found within the FCR sheath, 1 penetrated the FCR sheath, 6 crossed volar to the FCR sheath, and 6 were dorsal to the FCR tendon sheath. When comparing the branching patterns of the PCBMN from the median nerve, 4 branched from the volar aspect, 2 branched from the dorsal aspect, and 1 branched from the ulnar aspect of the median nerve. Conclusions: Variation in the course of the PCBMN relative to the FCR sheath is more than previously thought and can be expected in approximately 18.8% of patients.

Quantitative relationship of first metatarsophalangeal head morphology to hallux rigidus and hallux valgus.

BACKGROUND: Previous qualitative studies have linked first metatarsal head morphology with hallux valgus (HV) and hallux rigidus (HR). This study used a quantitative measurement of 1st MT radius of curvature to assess if HR MT heads were flatter than HV heads. METHODS: Weight bearing foot films were used in HV, HR, and normal patients (no forefoot complaints) to measure the metatarsal head radius of curvature (normalized by dividing the radius of curvature by the first metatarsal length to adjust for magnification and foot size). RESULTS: Radiographs from 299 feet were analyzed (105 normal, 57 HR, and 137 HV). The mean normalized radius of curvature was smaller in HV than HR, with normal feet in between (p<.05 for all comparisons). Metatarsal head curvature did not vary with age, weight, or BMI. CONCLUSION: These quantitative measurements are consistent with qualitative observations, validating the use of subjective metatarsal head morphology assessments.

Integrin engagement mediates the human polymorphonuclear leukocyte response to a fungal pathogen-associated molecular pattern.

Extravasation of leukocytes from peripheral blood is required for an effective inflammatory response at sites of tissue infection. Integrins help mediate extravasation and navigate the leukocyte to the infectious source. A novel role for integrins in regulating the effector response to a cell wall component of fungal pathogens is the subject of the current study. Although phagocytosis is useful for clearance of unicellular fungi, the immune response against large, noningestible hyphae is not well-understood. Fungal beta-glucan, a pathogen-associated molecular pattern, activates production of superoxide anion in leukocytes without the need for phagocytosis. To model polymorphonuclear leukocyte (PMN) recognition of fungi under conditions in which phagocytosis cannot occur, beta-glucan was covalently immobilized onto tissue culture plastic. Plasma membrane-associated respiratory burst was measured by reduction of ferricytochrome C. Results show that the human PMN oxidative burst response to immobilized beta-glucan is suppressed by addition of beta(1) integrin ligands to the beta-glucan matrix. Suppression was dose dependent and steric hindrance was ruled out. beta(1) integrin ligands did not affect respiratory burst to ingestible beta-glucan-containing particles, phorbol esters or live yeast hyphae. Furthermore, in the absence of matrix, Ab activation of VLA3 or VLA5, but not other beta(1) integrins, also prevented beta-glucan-induced respiratory burst. beta(1)-induced suppression was blocked and burst response restored by treating neutrophils with either the cell-binding fragment of soluble human Fn, cyclic RGD peptide, or Ab specific to VLA3 or VLA5. Together these findings extend the functional role of beta(1) integrins to include modulating PMN respiratory burst to a pathogen-associated molecular pattern.

Effects of selective and nonselective PGE2 receptor agonists on cervical tensile strength and collagen organization and microstructure in the pregnant rat at term.

OBJECTIVE: The purpose of this study was to determine which of the 4 PGE2 receptors (EP1-EP4) is involved in cervical ripening in the rat, and to correlate its activity with changes in tensile strength and collagen microstructure. STUDY DESIGN: We assessed tensile strength after administration of selective and nonselective PGE2 receptor agonists. Quantification of collagen organization and microstructure was accomplished with polarized light microscopy and transmission electron microscopy. RESULTS: Selective agonists for EP1-3 did not produce significant differences when compared with each other or control animals. Significant differences in tensile strength, proportion of organized collagen, and microstructure were found between treatment and control animals with the nonselective receptor agonist (PGE2). This was taken as an indirect measure of EP4 activity. CONCLUSION: Changes in cervical collagen organization and microstructure are quantifiable and correlate with changes in tensile strength. These data implicate EP4 as the PGE2 receptor involved in producing these changes in the rat cervix.