Abstract: The surgical saw blade and hub of this invention includes a saw blade and instrument hub which connect the saw blade to the instrument such that no portion of the instrument extends beyond the blade. The blade includes a washer having a plurality of radially extending slots in communication with the central bore of the washer. Alternating slots of the washer are truncated or otherwise do not fully extend through the washer. The truncated slots form shoulders or lans within the washer. The center opening of the washer is in alignment with a base opening in the blade and accommodates a hub from the powered instrument. The hub of the powered instrument includes a plurality of radial fins extending outwardly therefrom. The fins abut against the shoulders of the washer to lock the blade to the hub. A helical spring is provided to maintain pressure against the blade and thereby retain the blade and hub in a locked configuration.

Abstract: A fluid pump 20 used in a lavage instrument 10 that is driven by vacuum pressure is disclosed. Fluid pump 20 includes a fluid housing 30 connected to an external fluid source and a pneumatic cylinder 50 connected to an external vacuum source. A diaphragm 40 is shiftably disposed within fluid housing 30 to define an inner fluid chamber 31. Pneumatic cylinder 50 includes a cylinder casing 60 and a reciprocating piston 70, which defines a vacuum chamber 61. Piston 70 includes a poppet valve 80 and is connected to diaphragm 40 by two push rods 68. Negative pressure within vacuum chamber 61 draws piston 70 forward and compresses a return spring 67. As piston 70 is drawn forward, piston 70 pushes diaphragm 40 forward to expel fluid from fluid chamber 31 through an outlet port 36. Piston 70 is drawn forward until poppet valve 80 is unseated by its engagement with a post 66 which extends longitudinally from casing end wall 44.

Abstract: The coating for a prothesis system has a resorbability gradient in the direction perpendicular to the surface of the prothesis system, the internal layer being the least resorbable. It can consist of phospho-calcium material or of two or several successive layers having different resorbabilities and having said resorbability gradient. The prothesis systems covered with the coating according to the invention are used in surgery for the provision of thigh-bone protheses as well as protheses for the facial, ear, nose and throat surgery and the like.

Abstract: The instrumentation set of this invention assists the surgeon in selecting the proper implant components, in determining the amount of distal bone to resect, and in aligning instrumentation designed to resect the bone. The instrumentation set provides numerous systems for verifying to the surgeon that he has correctly aligned the instruments prior to removing any bone.The set includes a rotational alignment guide, which aids the surgeon in establishing the appropriate rotational alignment for the knee as determined by reference to standard femoral landmarks such as the posterior condyles and epicondyles. The rotational alignment guide includes a slot for guiding a saw blade for removal of the posterior condyles of the femur.The set further includes a tensor designed to tense the knee joint in flexion and extension. The tensor is activated by a torque wrench so that a measured amount of tension force can be applied to the joint.

Abstract: A method for molding bone cement to a prosthetic implant in which a cement mixture absent any amine initiators is molded about the implant and polymerization is initiated by exposing the cement mixture to a radiation source. The method eliminates the manufacturing timing problems of molding a polymerizing bone cement mixture to an implant.

Abstract: A method of forming a cast orthopaedic implant having a porous surface layer is disclosed. The method includes placing a porous layer on a wax replica of the implant such that a portion of the pores of the layer are filled with the wax material. The wax replica and porous surface layer are coated by a ceramic material consistent with investment casting technology. The ceramic material fills the remainder of the pores of the porous layer. After the ceramic material is solidified, the wax material is melted away leaving a cavity within the ceramic material. The pores once filled by wax are now exposed and extend into the cavity. A molten metal is poured into the cavity and partially melts the exposed porous layer to form a melt bond with the molten metal. When the metal is cooled, the ceramic material is stripped away exposing the portion of the porous layer previously filled with the ceramic medium.

Abstract: This invention provides for a pin cutter which forms an annular groove about the periphery of the pin. The cutter includes a cutting wheel that is rotated relative to the pin and is gradually tightened to force the cutting wheel into the pin and thereby widen the groove. The cutting action is similar to a pipe cutter used by plumbers to cut a length of copper tubing. The operator can continue tightening the cutting wheel against the pin until the pin is severed. A portion of the pin extends through the housing of the cutter. Since the pin is gradually cut, less force is required to sever the pin. Further, less force is released by the pin as it is severed. The severed and free portion of the pin is retained within the housing in a controlled manner.

Abstract: A cement retaining shield for use when seating an acetabular prosthetic implant into a cement filled acetabulum. The shield includes at least two leaf-like sections which may be displaced outwardly by rotation of a cam to cover a substantial portion of the patient's acetabulum. The device is particularly useful in applying force through the shield to compress the cement into the acetabulum to improve bonding at the cement-bone interface and at the cement-implant interface. Preferably, the shield is in the form of a planar disc and the leaf-like sections are positioned in overlying relationship to the disc. The sections, responsive to the rotation of a cam, may be extended outwardly of the disc.

Abstract: An oscillating surgical blade formed such that the thickness of the blade adjacent the side edges is reduced relative to the effective thickness of the body of the blade. Therefore, when the side edges of the blade mushroom due to contact with a saw guide slot, the resultant thickness of the mushroomed edges is less than or equal to the effective thickness of the blade body.

Abstract: A method of forming an orthopaedic implant having a porous surface, the method including the steps of providing a porous surface including a porous layer attached to a substantially solid layer; positioning the porous layer on the orthopaedic implant; providing a high energy density welding device capable of producing a high energy density weld beam; and forming a weld bead substantially about the periphery of the porous layer by directing the high energy density weld beam about the periphery of the porous layer, wherein the weld bead bonds the porous layer to the implant.

Abstract: A milling apparatus 2 including an articulated cutter 20 and an inverted L-shaped frame 10 for removing a unique geometric volume of bone to receive a prosthetic implant stem. Cutter 20 is housed within frame 10 for rotational movement about its longitudinal axis and lateral movement along a guide 16, which extends laterally from frame 10. Cutter 20 includes a pair of articulated arms 30, 32 each carrying a plurality of cutting blades 40. The proximal end 22 of cutter 20 is seated in an elongated non-radial race 17 formed in guide 16. Articulated arms 30, 32 provide a "scissoring" action which allows cutter 20 to be compressed longitudinally when shifted to one end of race 17 and extended longitudinally when shifted to the opposite end of race 17. The scissoring action of arms 30, 32 also changes the angle of the cutting face of blades 40 carried by arms 30, 32. Consequently, milling apparatus 2 creates a receiving cavity having an egg-shaped cross section.

Abstract: A fluid applicator 10 used to prepare a surgical site on a patient's skin is disclosed, which irrigates a surgical site and simultaneously collects excess irrigation fluids from the surgical site and returns the collected fluids to a fluid reservoir. Applicator 10 includes a disposable fluid reservoir 10 and a reusable motor assembly 50. Fluid reservoir 20 includes a sponge 48. Motor assembly 50 includes a motor 70 and a reciprocating diaphragm 80. Motor assembly 50 is connected to the open end of fluid reservoir 20 to enclose and seal a quantity of prep solution inside the fluid reservoir. Motor 70 reciprocates diaphragm 80 back and forth within fluid reservoir 20. The forward stroke of diaphragm 80 causes a positive pressure inside fluid reservoir 20, which displaces the irrigation fluid through a one way valve 30 and a spray nozzle 34 onto the surgical site. Excess irrigation fluid is absorbed by sponge 48 as applicator 10 is moved over the surgical site.

Abstract: The alignment guide of this invention includes a cam rotatable about the longitudinal axis of the alignment guide as defined by an intramedullary rod. A base plate is pivotally connected to the intramedullary rod and includes a pair of cam followers positioned on opposite sides of the intramedullary rod. In use, as the cam is rotated relative to the rod, the cam followers ride against the cam causing the plate to pivot or angulate relative to the rod. A plurality of indicia are formed on the cam to indicate to the surgeon the relative angle between the plate and the rod. The base plate includes a quick connect mechanism to permit the surgeon to quickly attach a device such as a cutting guide or pinning guide to the base plate. The cutting guide is fixed relative to the base plate such that the cutting guide will be at the same angular orientation as the plate relative to the intramedullary rod.

Abstract: This invention includes a ratchet wheel carried by the locking bolt and engaged by a pin carried by the targeting guide. The pin and ratchet wheel permit the locking bolt to rotate in a tightening direction and prevent the bolt from rotating in a direction to cause the bolt to loosen. Therefore, during impact, the bolt is prevented from loosening. After the IM rod is inserted and the surgeon wants to remove the targeting guide, the pin is shifted and locked into a disengaged position with the ratchet wheel to permit the locking bolt to rotate without obstruction. The ratchet pin may be locked in its retracted position.

Abstract: The milling instrumentation of this invention provides a milling guide connected to the femur for accommodating a milling device. The milling instrumentation includes an alignment guide which is used by the surgeon to set a femoral bracket or base on the medial and lateral sides of the exposed femur adjacent its distal end. Once the brackets are set, the alignment guide is removed and a milling guide is connected to the bases. The milling guide establishes a series of reference planes each including a slot. A powered milling device having a burr connected thereto is guided by the slots along the reference planes to accurately mill away a portion of the bone. The milling device includes a bobbin-shaped tip which positively engages the slots to ensure that the milling device is held substantially perpendicular to the reference planes of the milling guide.

Abstract: The insertion instrument of this invention includes a generally cylindrical handle portion and a cup engaging portion held in a spaced relationship by an arcuate intermediate portion. Handle portion includes a longitudinal throughbore and an impaction head. The cup engaging portion includes a rotatable threaded stud for threaded accommodation within a threaded hole of an prosthetic acetabular cup. The stud includes a head having a recess formed therein for accommodating a driving device. The longitudinal bore of the handle portion and the head of the threaded stud are placed in alignment such that the shaft of a screwdriver extending through the threaded bore is aligned with the head of the screw. Therefore, a surgeon using the instrument of this invention does not need to have a clear view of the threaded stud to attach a screw driver. This is especially useful after the surgeon has impacted the acetabular cup within a prepared acetabulum and needs to remove the insertion instrument.

Abstract: The mixing apparatus and method of this invention combines centrifugation and vacuum mixing to provide a device for the centrifugation of cement under a partial vacuum for the reduction of porosity within bone cement. The results of centrifugation under a vacuum are an improvement over the results achieved in standard centrifugation or standard vacuum mixing techniques. The device includes a receptacle which is spun rapidly about an axis under a partial vacuum. Creating a partial vacuum within the receptacle causes the air bubbles trapped within the cement to grow in size. The centrifugation causes the larger air bubbles to migrate through the cement toward the axis of rotation. Centrifugation works especially well under a partial vacuum due to the increased size of the air bubbles, in that larger bubbles migrate easier and quicker than smaller bubbles. Under centrifugation, the smaller air bubbles are compressed to such a degree that they become insignificant within the cement.