Abstract: A surgical access portal includes a seal housing, a sleeve mountable to the seal housing, and a seal disposed within the seal housing. The seal includes a first layer having an opening for the reception and passage of a surgical instrument, a second continuous layer for providing a fluid tight seal in the seal housing in the presence and/or in the absence of a surgical instrument, and a third layer having an opening for the passage of a surgical instrument therethrough. The first and third layers have a higher density than the second layer for maintaining the second layer in an axially compressed state therebetween.

Abstract: A surgical access device including a frame, first and second supports, and first and second retractor blades releasably coupled with the first and second supports, respectively. The frame has first and second arms. The first support is releasably coupled with the first and second arms. The second support is slidably mounted on the first and second arms. The second support is movable between a first position with the retractor blades in close cooperative position and a spaced apart position with respect to the first support. The first and second retractor blades each have a distal end portion configured and adapted to engage a vertebral body. In one method of use, the retractor is inserted through an incision in first orientation with the blades in close approximation and rotated approximately 90°, before spreading the retractor blades to retract tissue.

Abstract: A medical assembly includes a cannula and a sealing cap releasably coupled to the cannula. The cap includes a body and a sealing member integrally molded with the body to form a fluid-tight seal between the cap and cannula. The cap includes a member defining an opening for passage of a medical instrument therethrough in a fluid-tight manner. The member includes a first portion surrounding the opening and being thickened to limit tearing of the first portion, and a second portion surrounding the first portion being tapered down in thickness toward the first portion to increase flexibility of the member. The assembly includes a shaft receivable in a lumen defined by an inner surface of the cannula. The shaft includes a protrusion and the inner surface further defines a protrusion receiving formation.

Abstract: A tissue retractor generally includes a pair of arms that are pivotally coupled to each other and each have a finger grip portion on a first end and a working portion arranged on an opposite second end. Each of the second ends comprises an elongated shaft that extends along an axis. A pair of paddles each having a planar engagement body and a mounting portion are pivotally coupled to a corresponding elongated shaft. The paddles are selectively rotatable around the respective axes.

Abstract: A retracting eye drape assembly is disclosed for use around a patient's eye to seclude and seal off the operative field during eye surgery. The drape assembly includes a retraction member connected to the drape and configured to engage the patient's eyelid, an extension member connected to the retraction member or to the drape and configured to substantially enclose the patient's eyelid, and a retraction flap configured to secure the patient's eyelid in a substantially retracted position. A method of applying an eye drape assembly is disclosed. After application of the drape to the patient's face, and while the patient's eyelid is closed, the patient's eyelid is engaged by a retraction member connected to the drape and retracted. While retracted, the patient's eyelid is substantially enclosed to seclude the eyelid and eyelashes from the operational area. The secluded eyelid and eyelashes are then secured in a retracted position.

Abstract: A wound retractor for retracting a surgical incision includes an inner ring, an outer ring and a distensible sleeve coupled to the inner and outer rings. The outer ring includes at least a pair of circular tubes coupled to each other. At least one of the circular tubes includes a lumen and a split that forms open ends. A noncompliant tubular hoop having a split therein is positioned in the lumen. The tubular hoop is oriented with its open ends positioned away from the split of the circular tubes. A core is positioned in the lumen of the tubular hoop. The core has a first end and a second end and is oriented with the ends positioned away from the split in the tubular hoop. The circular tubes may be parallel or may form a helical pattern similar to a Mobius strip.

Abstract: A method of performing an operation, e.g. a spinal operation, on a patient using a retractor comprising a pair of blade assemblies which are adapted to open about a set of axes that are not parallel to a third spatial axis, and further comprising a pair of arms, which are adapted to move the pair of blade assemblies apart from one another in the third spatial axis. In the method, the blade assemblies are closed to assume a low profile, inserted into a relatively small incision, and stretched apart from each other, thereby stretching the skin about the incision to form an aperture longer than the incision. The blade assemblies are then opened by rotating the blades about the set of axes, stretching the skin around the incision in a second direction that is substantially perpendicular to the first direction (i.e. the direction of the incision.).

Abstract: A deployable jaws retraction device is provided for retracting a body organ away from an operative site without occupying an incision or surgical access port during the surgical procedure. The deployable jaws retraction device includes a jaw assembly having two or more jaws joined at one end and a retention device to maintain the jaws of the closed condition about a target body organ. The deployable jaws retraction device additionally includes an anchoring assembly for securing the jaw assembly and body organ away from the operative site during the surgical procedure. The anchoring assembly includes a needle having a tissue penetrating tip and a length of suture material connecting the needle to the jaw assembly. There is also provided an applicator instrument for applying the deployable jaws retraction device onto a target body organ.

Abstract: A transvaginal ultrasound probe speculum is designed for use with a generally cylindrical elongated ultrasound probe. The speculum has an elongated blade having a proximal end and a distal end, and a connector, such as a collar. The speculum has a lever that cooperates with the collar and the elongated blade for pivoting the blade relative to the ultrasound probe so that the blade and the ultrasound probe serve as the blades of the speculum.

Abstract: A medical instrument serves for creating an access for a minimally invasive intervention and has a body having a longitudinal axis. The body is assembled of at least two parts, each of said parts having edges extending along a direction of said axis. Each of said parts having edges extending along a direction of said axis. Each part has a distal section merging into a proximal section standing outwardly from said longitudinal axis. In a first position, the distal end section of the parts are joined along said edges to form a distal body with the proximal section standing away. In a second position, the proximal sections of said parts are joined along said edges to form a hollow proximal body with said distal end section spreaded outwardly. The edges are provided with interacting features which are designed to block a lateral sliding of said joined parts transversely to said edges.

Abstract: A steerable multi-linked device. The device includes a first multi-linked mechanism and a second multi-linked mechanism. At least one of the first and second multi-linked mechanisms is steerable and includes a modular link assembly at an end thereof. The modular link assembly includes a base, and a tip removably connected to the base.

Abstract: This application presents minimally-obstructive and structurally-adjustable retractors which afford an open work area of desirable size and enhanced visualization for a surgeon about the perineum and the posterior vaginal wall of the patient. The retractors may be lightweight and compact, and also configured and dimensioned to minimize slippage during use. The retractors may retract the engorged labia of the postpartum patient as well as the vaginal walls. The device may also be used as a speculum.

Abstract: An instrument access device 1 comprises a proximal member 25 for location externally of an opening into a body cavity. A first connector 20 extends between the proximal member 25 and a first instrument receiver 2. A second connector 21 extends between the proximal member and a second instrument receiver 3. Instrument seals can be housed in relatively rigid housings for added strength.

Abstract: An anoscope kit comprising an anoscope having a plurality of spaced apart fingers having free ends and a dilator removably positionable within the anoscope to aid insertion of the anoscope. The dilator has a proximal region, an intermediate region and a distal region, the distal region including an enlarged distal head. A ramped surface extends from the enlarged distal head toward the intermediate region, the intermediate region having an outer surface to contact the fingers of the dilator.

Abstract: A medical instrument for manipulating, in particular retracting tissue or an organ in the human or animal body, comprises an elongated shaft having a distal portion introducible into the body, and at least one working element arranged at a distal end portion of the shaft for manipulating the tissue or organ. The at least one working element comprises at least one magnetically acting element producing a magnetic field for manipulating the tissue or organ. A method for manipulating, in particular retracting tissue or an organ uses the instrument.

Abstract: A retracting two-piece cannula for distracting soft tissue from bone (e.g., the articular surface of a knee) to provide a surgical workspace for osteochondral repair. After inserting an outer cannula provided with a threaded outer surface into an incision (preferably widened by one or more dilators), the outer cannula is rotated to engage the threaded outer surface with the soft tissue to be distracted. An inner cannula is then inserted into the outer cannula and advanced until it contacts the articular surface. Further relative movement between the inner and outer cannulas causes the outer cannula to be drawn away from the articular surface, thereby retracting the soft tissue and establishing the workspace. The inner and outer cannula are then locked together to maintain the workspace, and an osteochondral core may be introduced through the inner cannula.

Abstract: The invention relates to a tool for parietally anchoring a living being's organ (70) comprising means (12, 16, 24) for anchoring said organ, means (36) for fastening at least one pulling element (37) to said anchoring means, wherein said pulling element is fixable to the abdominal wall of said living being in such a way that it makes it possible to lift and keep in suspended position the organ anchored by anchoring means (12, 16, 24) in order to display an anatomical structure during a surgical intervention, in particular in laparoscopy or coeloscopy. The inventive tool also comprises means (14, 22, 28, 38) for grasping and manipulating said anchoring means by a surgical clip. The size of the tool is selected in such a way that it is enabled to pass through a laparoscopic or coelioscopic trocar. A parietally anchoring device is also disclosed.

Abstract: A surgical triangulation device and method of use is disclosed. The surgical triangulation device includes an elongate member, the elongate member defining a longitudinal axis and being adapted for insertion through a surgical access portal. The surgical triangulation device also includes a platform pivotably attached near a distal end of the elongate member, the platform defining a plurality of lumens and a central opening therethrough. The platform has a first position, where a first end of the platform is positioned proximate to the elongate member and a second end of the platform extends distally past a distal end of the elongate member, and a second position, where the platform is nearly orthogonal to the longitudinal axis.

Abstract: A surgical system includes one or more arms defining a passageway therethrough. The arm includes a proximal portion configured for positioning externally of a patient's body and a distal portion configured for positioning within an internal body cavity. The distal portion includes first and second articulatable segments spaced apart from one another and capable of independent articulation between a substantially straight configuration and an articulated configuration. A first articulation assembly is coupled to the proximal portion of the one arm and is transitionable between a first state and a second state for articulating the first articulatable segment between the substantially straight configuration and the articulated configuration. A second articulation assembly is coupled to the proximal portion of the arm and is configured to move between a plurality of positions for articulating the second articulatable segment between the substantially straight configuration and the articulated configuration.

Abstract: A surgical access port and method for achieving triangulation is disclosed, the surgical access port comprising a housing and an articulation structure. The housing is comprised of a cylindrical member having proximal and distal ends, and defining a longitudinal axis. The articulation structure is comprised of at least two lumens, each of the at least two tubular members disposed in a respective lumen, at least two rotating members disposed along each of the at least two tubular members, an actuating member, and a rigid member connecting each rotating member to each tubular member. The tubular members are configured to receive instruments for use in minimally invasive procedures.

Abstract: A surgical access port and method of using is disclosed, the surgical access port comprising a cylindrical member defining a longitudinal axis and having proximal ends defined by a pair of rims oriented substantially transverse to the longitudinal axis. At least one lumen extends from the proximal end to the distal end of the cylindrical member, the lumens substantially parallel to the longitudinal axis. A sealing member having proximal and distal ends with opposing openings is disposed externally of the cylindrical member, the opening at the proximal end of the sealing member in contact with the proximal end of the cylindrical member.

Abstract: An incrementally adjustable wound retractor, which provides access to a body cavity, includes an inner ring having a diameter greater than the desired diameter of the wound incision, an outer ring having an annular axis and a diameter greater than the desired diameter of the wound incision, and a flexible sleeve disposed in a generally cylindrical form between the inner and outer rings. The outer ring includes first and second circular tubes spaced apart axially with each including a lumen having a rigid, noncompliant split hoop positioned therein. The outer ring may be rolled over itself and around the annular axis to retract the sleeve with sufficient force to stretch the incision to the desired diameter. A gel cap seal may be coupled to the outer ring outside of the biological body to seal the opening produced by the wound retractor between the body cavity and outside the body cavity.

Abstract: A retraction system and method are provided for retracting tissues surrounding a surgical site. In one aspect, a method including engaging slide connections between a guide dilator and a plurality of tissue engaging members and sequentially enlarging an incision using the guide dilator and the plurality of tissue engaging members. In another aspect, a method of inserting a plurality of tissue engaging members into an incision including fixing tip portions of the plurality of tissue engaging members in an insertion configuration, advancing the tip portions into an incision, and restricting movement of the tip portions away from the insertion configuration. A guide dilator system comprising an elongate body, a plurality of tissue engaging members, and slide connections between the elongate body and the tissue engaging members is also provided.

Abstract: Certain embodiments provide surgical retractors that include an arm and a blade, the arm including an opening and a first notched surface comprising a plurality of notches that extend radially outward from the opening, the blade including a nipple and a second notched surface comprising a plurality of notches that extend radially outward from the nipple. Attaching the blade to the arm such that the notched surfaces mate can secure the blade relative to the arm such that the blade cannot swivel radially about the opening. Certain embodiments provide methods for securing a retractor blade that can include inserting a nipple on a retractor blade into an opening and mating a first notched surface comprising a plurality of notches that extend radially outward from the opening with a second notched surface comprising a plurality of notches that extend radially outward from the nipple.

Abstract: Surgical release apparatuses, systems and methods are provided. The apparatuses, systems and methods can include one or more cannulas having a base and an insertion body extending from the base with a chamber passing through the base and the insertion body. The cannula can have a movable retractor attached thereto. The retractor configured to facilitate creation of space between the insertion body of the cannula and the retractor. An obturator can be used and can provide a support body configured for insertion into the chamber of the cannula to facilitate the guidance of the cannula. A blade can be provided with a handle, a blade body, and a cutting edge. The blade configured for engaging and being guided by the cannula for the cutting edge to make an incision. One or more spatulas can also be provided. The spatulas can be configured to provide guidance to the blade.

Abstract: A soft tissue protection surgical shield protects collateral soft tissue from damage during a surgical procedure within a surgical space of a body. The shield comprises an elongated flexible shield having a proximal end and a distal end. The proximal end has a first opening and the distal end has a second opening. The shield further comprises a side wall between the proximal and distal ends that defines the first and second openings. The side wall is conformal to the surgical space and arranged to resist perforation by surgical instruments in use during the surgical procedure, and also to define and maintain the access pathway to the surgical site.

Abstract: A medical assembly includes a platform which is securely mountable to an operating room fixture, and a plurality of arms or arm modules coupled to the platform and each with a grasper for holding a surgical instrument or port. The medical assembly is particularly applicable for laparoscopic surgery although it is not limited thereto.

Abstract: A retractor system includes a rail having two opposed widened rail portions separated by a narrowed portion, each widened portion engageable by a separate clamp. The clamps are configured to support the rail to a fixed surface, or to support a surgical device. Each clamp may independently be positioned or slid along the rail to a desired location without interference with a clamp on an opposing widened rail portion. A device clamp is formed of spherical mating portions which enable alignment of a surgical device along six degrees of freedom, and tightenable by securing a single fastener. A retractor blade mount enables an angular and tilting disposition of a retractor blade, as well as remote manipulation of the retractor blade.

Abstract: An assembly for tissue retraction in surgery includes a pair of arm members removably positioned on and movable along an elongate support member. The arm members each include an external housing, a locking member positioned within the external housing and a passageway extending through the external housing and the locking member. The elongate support member extends through the passageways and the locking members are releasably biased into engagement with the elongate support member to allow the arm members to move in opposite directions along the elongate support member and prevent the arm members from moving toward one another. Each arm member further includes a rotatable engagement portion engageable with a respective retractor portion and a locking element releasably biased into engagement with the engagement portion to limit rotation of the engagement portion to a first direction relative to the arm member.

Abstract: The retractor system for use in spinal surgery and other types of surgical procedures that is a simple and efficient solution for minimally invasive access to thoracolumbar spine is disclosed. The fully customizable design allows the surgeon to independently angle the retractor blades and expand the retractor in both cephalad-caudal and medial-lateral directions. With an offering of a range of blade lengths, access can be tailored to the patient's anatomy. Auxiliary instruments such as the retractor inserter, universal hex driver and blade removal instrument allow quick and controlled access to the surgical site. The retractor system provides versatility and control ensuring minimal tissue trauma.

Abstract: A surgical apparatus for positioning within a tissue tract accessing an underlying body cavity includes a seal anchor member that includes a ring and a disc that are repositionable relative to one another, such that the height of the seal anchor member is adjustable and the angular positions of the disc and the ring, relative to one another, are adjustable.

Abstract: A single use disposable shield and supportive stand for placement on a medical tool such as a suction catheter comprises a transparent body for protecting a responder from bodily fluids of a patient during suctioning of the oral or nasal cavities of a patient. As well the device acts as a supportive stand and securing agent for multiple medical devices and tools The body has an aperture for receiving a bushing. The bushing has an aperture for receiving the medical tool or device.

Abstract: A surgical access apparatus includes a liner base and an access housing for positioning outside the body. The liner base includes an inner member adapted for insertion through an opening within body tissue for positioning within the body; a sleeve member connected to the inner member and dimensioned to extend from the inner member through the opening within the body tissue, and a plurality of tensioning elements connected to the inner member and associated with the sleeve member to impart a tensioning effect on the sleeve member. The access housing includes a first element and a second element. The second element is operatively connected to the tensioning elements and adapted for rotational movement relative to the first member to cause the tensioning elements to displace the inner member toward the access housing and to cause the sleeve member to engage and retract tissue defining the opening within the body.

Abstract: The present invention provides an organopexy tool (10, 40) comprising a locking part (11, 41) and suture thread (12, 42). Locking part (11, 41) is made of a rod-shaped part (13, 14), and the coil spring (14) that covers the rod-shaped part (13, 43) and is affixed to one end (13a, 43a) of rod-shaped part (13, 43), and suture thread (12, 42) is connected to the middle of rod-shaped part (13, 43) through the inside of coil spring (14) from one end (13b, 43b) of rod-shaped part (13, 43). Insertion tool (20, 50) has a puncture needle (21) for insertion that can house the locking part (11, 41) and a tubular push-out part (22) that is inserted into puncture needle (21) to push locking part (11, 41) out of the tip (25).

Abstract: A portal assembly for positioning within an incision to access an underlying body cavity including a collar and a compressible portal member. The collar includes an elongate member that defines a longitudinal axis and has a longitudinal passageway. The portal member includes one or more longitudinal ports for passage of a surgical object. The portal member is positionable within the longitudinal passageway of the collar to thereby adjust the length of the portal assembly within the incision.

Abstract: A wound retractor (320) comprises a distal ring (3) for insertion through a wound opening (6), a proximal ring (4) for location externally of the wound opening (6), a valve (10) mounted to the proximal ring (4), and a sleeve (2) for retracting laterally the sides of the wound opening (6). The wound retractor (320) also comprises a flexible release member (81) for releasing the distal ring (3) from a retracting configuration for removal of the distal ring (3) from the wound opening (6). A first end (301) of the release member (81) is attached to the valve housing (102), the release member (81) loops around the distal ring (3), and a second end (302) of the release member (81) is movable relative to the proximal ring (4) to release the distal ring (3) from the retracting configuration.

Abstract: Embodiments of a surgical access port system that comprises a retractor that is adapted for being coupled to a cap and that is particularly useful in natural orifice surgery are described. The retractor comprises an outer ring, wherein the outer ring is configured to be disposed proximate the natural orifice of the patient and substantially surround the orifice; a tubular body; and a funnel segment extending between and coupling the outer ring and the tubular body, wherein the funnel segment provides a diametric reduction between the relatively large diameter of the outer ring and the relatively smaller diameter of the tubular body, which is sized to fit within a natural orifice with minimal distention of the orifice.

Abstract: A vascular access port is described that is elongate in form. A distal end is coupled to a tube which leads into a body lumen. A proximal end has a head thereon with a septum which can be repeatedly penetrated by a needle and reseal, for repeated administration of medications or other compositions through the port and into the body of the patient. A wing is attached to the body that has two positions including a streamlined first position for implantation and a wider second position for stabilization of the port after implantation. A stay is preferably also provided to abut the wing when in the second position to keep the wing in the second position when fully deployed.

Abstract: This application presents minimally-obstructive and structurally-adjustable retractors which afford an open work area of desirable size and enhanced visualization for a surgeon about the perineum and the posterior vaginal wall of the patient. The retractors may be lightweight and compact, and also configured and dimensioned to minimize slippage during use. The retractors may retract the engorged labia of the postpartum patient as well as the vaginal walls. The device may also be used as a speculum.

Abstract: An apparatus including a flexible length of cord and three tissue connectors positioned at the opposite ends of the cord and at an intermediate position of the cord is designed to be laparoscopically inserted through the abdominal wall and into the abdominal cavity, and used to move a first internal organ to a position away from a second internal organ where the apparatus holds the first internal organ in the position without further manual input, thereby providing surgical access to the second internal organ.

Abstract: A system for treating a lumbo-sacral junction includes at least one dilator configured to create a passageway from a direct lateral trajectory in a body defining a longitudinal axis. A cutting instrument is configured to create a bore, oriented at an angle from the longitudinal axis, in a L5 vertebrae of the body extending to a central portion of a L5-S1 intervertebral disc space of the body. A delivery instrument is configured to deliver an implant through the bore to the central portion of the L5-S1 disc space. Methods of use are disclosed.

Abstract: An apparatus for allowing simultaneous use of at least two surgical instruments through a single incision. The apparatus includes a first part having a proximal end, a distal end, an inner surface and an outer surface. The outer surface engages an incision and holds the incision in an open position. The inner surface defines a passageway through the first part from the proximal to the distal ends. The apparatus also includes a second part attached to the proximal end of the first part for sealing the proximal end of the first part and having at least two ports for receiving a surgical instrument. At least one of the ports includes a ball joint to allow articulation of the port relative to the second part. The ball joint allows the orientation of the port and the surgical instrument within it to be moved easily relative to the apparatus.

Abstract: A steerable multi-linked device. The device includes a first multi-linked mechanism and a second multi-linked mechanism. At least one of the first and second multi-linked mechanisms is steerable and includes a modular link assembly at an end thereof. The modular link assembly includes a base, and a tip removably connected to the base.

Abstract: Devices and methods are provided for accessing a bodily opening that, among other things, are safe, reliable and repeatable. One embodiment of a device for anchoring to tissue includes an elongated tube and a magnet. The elongated tube has a proximal end opposite a distal end, and defines a central axis. The magnet is attached to the distal end of the elongated tube and has a magnetic field attractive to the magnetic material in the tissue. The magnet has an annular shape defining an aperture through which the elongated tube extends.

Abstract: An improved bone retractor tool includes a pair of arms pivotably connected to one in a pliers-like configuration and a pair of tissue engagement plates each having forward and rearward portions, each of the pair of tissue engagement plates mounted on the upper end of one of the pair of arms and extending generally parallel with one another when the pair of arms are in closed position. Forward bone engagement spikes are mounted on and extend forwards from the forward portions of the tissue engagement plates. A releasable securement mechanism is mounted on the pair of arms for releasably retaining the pair of arms in a selected position relative to one another, and a tensioning device is mounted on the pair of arms for tensioning the lower ends away from one another thereby forcing the pair of tissue engagement plates towards one another upon the securement mechanism being released.

Abstract: Methods and devices to prevent and/or treat breathing disorders (e.g., upper airways disorders) in mammals related to impaired airflow are described. Methods and devices apply force to soft tissue that avoids obstruction of airflow in the mammel's airway. Breathing disorders that are avoided by the methods and/or devices include apnea.

Abstract: A method, kit, and system to separate muscle fiber prior to threading pedicle screws. The kit and system include at least one dilator that is sized and shaped with a leading edge to expand and separate muscle fibers between the first and second pedicles. The dilator(s) expose the surgical area by separating the muscle fiber prior to threading the pedicle screws. Because the muscle fiber is spread, it does not need to be cut to place rods, which facilitates minimally invasive surgical methods.

Abstract: Methods and devices are provided to assist in providing multiple devices access to a surgical site through a single port. In one exemplary embodiment an access device includes a body having a plurality of ports. The ports can include at least one primary instrument port and at least one secondary instrument port. A self-sealing passageway can be disposed between the primary and secondary instrument ports to allow communication between the two ports. As a result, a surgical instrument can be repositioned from one port to another without removing the instrument from the access device. In one embodiment a combined end effector nominal width of surgical instruments disposed in the ports can be greater than a diameter of the primary instrument port and/or a diameter of the body of the access device. Exemplary systems and methods for performing procedures using multiple devices in a single surgical opening are also provided.

Abstract: Progressive Surgical Distraction Device (PSDD) intended for enabling gradual atraumatic access to cavities and zones inside the human body and for allowing controlled extraction of the liquids contained therein, particularly open foetal surgery and neurosurgery. It is composed of a set of cylindrical and semi-cylindrical parts of increasing diameters and decreasing lengths that fit into each other telescopically, each enabling the successive extraction of the inner part. The progressive distraction of the muscular fibres does not subject them to traction, avoids haemorrhages and allows the controlled diversion of liquids without accumulation of residues. The last part of the sequence is designed to allow an optimum mobilisation of the clamping system via directly viewed control of the intervention zone and surgical field.

Abstract: A surgical device is disclosed which can be utilized to access a surgical site within a patient. The surgical device can comprise a member insertable into a patient, a base member configured to be positioned against the patient, and a flexible sleeve extending therebetween. The surgical device can further comprise an upper member which can be assembled to the base member such that it can be rotated about an axis. The upper member and the base member can comprise corresponding retention features and slots which can permit the upper member to be rotated relative to the base member yet prevent the upper member from being disassembled from the base member unless the upper member and the base member have been aligned in a unique orientation.