The invention relates to a method of installing a medical device for reducing the risk of permanent damage to a hip joint of a human patient, said method comprising the steps of: exposing the hip joint through a surgical or arthroscopic procedure, fixating a first piece of said medical device to the femoral bone, fixating a second piece of said medical device to the pelvic bone, placing said first piece in connection with said second piece, holding said first piece to said second piece using a releasing member, and releasing said first piece from said second piece when a pre-determined strain is placed on said releasing member.

A medical device, and a method for using the device, for implantation in a hip joint, wherein said medical device is adapted to be fixated to the femoral bone and receive a prosthetic replacement for the caput femur having a spherical portion, and to be fixated to the pelvic bone by a connection via an elongated member fixated to said spherical portion of said prosthetic caput femur. Wherein an inner surface comprises an equator line, being the largest circular circumference of said inner surface. Further at least one extending portion passes beyond said equator line and circumferentially extends discontinuously along said equator line, such that a portion of said elongated member can be placed between said extension line and said equator line, when said medical device being implanted together with the prosthetic replacement for the caput femur.

An insert is advanced and at least partially secured into a prosthetic device configured for use in a joint. The prosthetic device includes a shell with a cavity defined by an interior surface. The interior surface includes first and second portions that share an edge and that abut an edge of the interior surface. The first portion includes a partially spherical surface while the second portion is a partially cylindrical shape. A maximum radius of the second portion is larger than a radius of the first portion. A center defining the maximum radius of the second portion is offset from a center defining the radius of the first portion. The geometry of the interior surface allows the insert to be advanced into the shell in a single orientation. When advanced sufficiently into the shell, the insert is rotated to constrain the insert within the shell.

An acetabular implant for a hip prosthesis including: a fixation cup defining an inner cavity having a substantially hemispherical shape, made of polyethylene and having, on its outer wall, means capable of favoring its fixation with cement within the acetabular cavity of the pelvis of the patient to be prosthesized, the inner cavity being coated with an armoring made of a biocompatible material of high hardness, said armoring defining the smooth inner cavity of substantially hemispherical shape intended to receive the mobile insert; an insert, mobile within said inner cavity and having its smooth outer surface intended to cooperate by ball and socket joint with the inner cavity of the fixation cup, and defining in turn a smooth inner cavity also having a substantially hemispherical shape; said mobile insert being made of high-density polyethylene; a prosthetic femoral head or prosthetic ball, secured to a femoral stem, of spherical shape and intended to be received in the inner cavity of the mobile insert and to form a second ball and socket joint.

A medical device for implantation in a hip joint of a patient is provided. The medical device comprising a first piece being adapted to be fixated to the femoral bone and a second piece adapted to be fixated to the pelvic bone. The medical device further comprises a releasing which in a first state is adapted to hold said first piece attached to said second piece, and in a second state release said first piece from said second piece. The releasing member is adapted to change from said first state to said second state when a predetermined strain is placed on said releasing member by the connection with the first or second piece. The medical device further comprises a calibration member for calibrating the pre-determined strain required for said releasing member to change from said first state to said second state.

A medical device for implantation in a hip joint of a patient is provided. The medical device is adapted to be fixated to the pelvic bone of the patient. The medical device comprises an inner and an outer surface, wherein a contacting portion, of said inner surface is spherical and adapted to face the center of the hip joint when said medical device is implanted. The medical device is adapted to receive a caput femur or a prosthetic replacement therefor having a spherical portion, wherein said medical device comprises at least one extending portion, extending said contacting portion of said inner surface such that said at least one extending portion clasps said spherical portion of said caput femur, or a prosthetic replacement therefor, such that said spherical portion is restrained in said medical device. Restraining the caput femur in the medical device reduces the risk that the hip joint dislocates when in use by the patient.

A medical device for implantation in a hip joint and fixated to the pelvic bone of a patient is provided. The medical device has an inner and an outer surface. A contacting portion, of the inner surface is spherical and adapted to face the center of the hip joint when the medical device is implanted. The medical device is adapted to receive a caput femur or a prosthetic caput femur which has a spherical portion. The medical device has at least one extending portion, extending the contacting portion of the inner surface such that the at least one extending portion clasps the spherical portion of the caput femur or a prosthetic caput femur, such that the spherical portion is restrained in the medical device. Restraining the caput femur in the medical device reduces the risk that the hip joint dislocates when in use by the patient.

A medical device for implantation in a hip joint comprising: a first part adapted to be fixated to the femoral bone of the patient; and a second part rotatably connected to the first part by means of a connecting member. The first part comprises a bowl-shaped inner contacting surface portion adapted to receive a bowl-shaped outer contacting surface portion of the second part such that the second part is rotatable, relative to the first part, around a point of rotation formed by the connecting member. The second part comprises a bowl-shaped inner surface adapted to receive a ball-shaped portion of a prosthetic replacement for the caput femur. The inner contacting surface comprises at least one extending portion extending beyond the equator line and being adapted to clasp the ball-shaped portion of the prosthetic replacement for the caput femur.

Provided is a joint replacement with a joint socket (10) having a concave joint surface (11), and with a joint insert (20) having a concave joint surface (21) and a convex joint surface (22) which are each delimited by a peripheral edge (23, 24). The convex joint surface (22) of the joint insert (20) is designed, in the assembled state, to form a first partial joint with the concave joint surface (11) of the joint socket (10). Moreover, the concave joint surface (21) of the joint insert (20) is designed, in the assembled state, to form a second partial joint with the convex joint surface (32) of a joint head (30). The joint socket (10) and the joint insert (20) each have a securing means (12, 25, 26) for preventing dislocation of the joint replacement.

A support apparatus for supporting an end of a distraction marrow nail includes a base plate attachable to the pelvis, and a mounting device on the base plate for mounting of the support end of the distraction marrow nail. The mounting device includes a ball seat having a cavity forming a ball seat surface for mounting a ball on the support end of the distraction marrow nail, wherein the inside radius of the ball seat surface corresponds to the outside radius of the ball, and wherein the ball seat is arranged so that the ball of the distraction marrow nail can be movably mounted such that the distraction marrow nail can perform a movement sufficient for an extensively normal movement pattern of a femur and cannot luxate out of the ball seat when implanted in the femur.