Hip joint device and method

Abstract

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.

1 - 2 . (canceled) 
     
     
         3 . A medical 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:
 a) an inner surface comprises an equator line, being the largest circular circumference of said inner surface,   b) at least one extending portion passes beyond said equator line, such that the end portion of said contacting portion of said inner surface forms a circular extension line having a smaller circumference than said equator line, and   c) said at least one extending portion 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.   
     
     
         4 . The medical device according to  claim 3 , wherein said extension line is placed dorsal to the equator line, when the medical device is implanted. 
     
     
         5 . The medical device according to  claim 3 , wherein said at least one extending portion extends circumferentially along said equator line, dorsal to the right-left axis of pelvis when being in a defined base position. 
     
     
         6 . The medical device according to  claim 3 , wherein said at least one extending portion extends circumferentially along said equator line, dorsal to the coronal pelvis plane PXY and proximal to the horizontal pelvis PXZ plane when being in a defined base position. 
     
     
         7 . The medical device according to  claim 3 , wherein said at least one extending portion extends circumferentially along said equator line, dorsal to the coronal pelvis plane PXY and distal to the horizontal pelvis PXZ plane when being in a defined base position. 
     
     
         8 . The medical device according to  claim 3 , wherein one extending portion extends circumferentially along said equator line dorsal to the coronal pelvis plane PXY and proximal to the horizontal pelvis PXZ plane, and one extending portion extends dorsal to the coronal pelvis plane PXY and distal to the horizontal pelvis PXZ plane when being in a defined base position. 
     
     
         9 . The medical device according to  claim 3 , wherein said at least one extending portion extends circumferentially along said equator line, in the proximal quadrant of the equator line when being in a defined base position. 
     
     
         10 . The medical device according to  claim 3 , wherein said at least one extending portion extends circumferentially along said equator line, in the distal quadrant of the equator line when being in a defined base position. 
     
     
         11 . The medical device according to  claim 3 , wherein two extending portions extends circumferentially along said equator line, in the distal and proximal quadrant thereof when being in a defined base position. 
     
     
         12 . The medical device according to  claim 3 , wherein said at least one extending portion extends circumferentially along said equator line, in the proximal and dorsal quadrant thereof when being in a defined base position. 
     
     
         13 . The medical device according to  claim 3 , wherein said at least one extending portion extends circumferentially along said equator line, in the distal and dorsal quadrant thereof when being in a defined base position. 
     
     
         14 . The medical device according to  claim 3 , wherein at least one extending portion extends circumferentially along said equator line, in the distal, dorsal and proximal quadrant thereof when being in a defined base position. 
     
     
         15 . The medical device according to  claim 3 , wherein at least a first portion of said medical device is an extending portion, extending beyond said circular equator line, and at least a second portion is a portion not extending beyond said circular equator line, wherein said second portion circumferentially extends along at least ¼ of said circular equator line, preferably along at least ⅓ of said circular equator line, more preferably along at least ½ of said circular equator line. 
     
     
         16 .- 39 . (canceled) 
     
     
         40 . A method using a medical device according to  claim 3 , for implantation in a hip joint of a patient, comprising the steps of;
 fixating said medical device to the femoral bone of the patient, and wherein said medical device comprises an inner and an outer surface, wherein a contacting portion of said inner surface is bowl shaped and spherical and adapted to face the center of the hip joint,   placing the inner bowl shaped surface facing proximally towards the center of the hip joint, and   fixating a prosthetic replacement for the caput femur fixated to the pelvic bone having a ball shaped spherical portion   receiving said prosthetic replacement for the caput femur inside said inner bowl shaped surface, 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,   clasping said prosthetic replacement for the caput femur, such that said spherical portion is restrained in said bowl shaped inner surface of said medical device.   
     
     
         41 . The method according to  claim 40 , wherein said medical device is adapted to receive the spherical portion of the prosthetic replacement for the caput femur, fixated to the pelvic bone by a connection via an elongated member fixated to said spherical portion of said prosthetic caput femur, wherein:
 a) said inner surface comprises an equator line, being the largest circular circumference of said inner contacting surface, being a surface adapted to be in contact with said caput femur replacement, and   b) said at least one extending portion passes beyond said equator line, such that the end portion of said contacting portion of said inner surface forms a circular extension line having a smaller circumference than said equator line, and   c) said at least one extending portion 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, wherein the method comprising the steps of;
 placing the inner surface involving the step of placing an inner surface comprising at least one extending portion 
 moving said femoral bone to place said elongated member between said extension line and said equator line. 
   
     
     
         42 . The method according to  claim 40  further including;
 cutting the skin in the hip region 
 dissecting the hip joint 
 implanting the medical device in a hip joint of a patient, 
 fixating a ball shaped replacement of caput femur on the opposite side therefore to the pelvic bone of the patient, 
 fixating a bowl shaped acetabulum replacement on the opposite side and therefore to the femoral bone of the patient, wherein said acetabulum replacement comprises an inner and an outer surface, having a contacting portion of said inner surface being spherical and bowl shaped 
 facing the inner surface to the center of the hip joint having at least one extending portion, extending a contacting portion for contacting the caput femur replacement, 
 placing a caput femur replacement, such that said extending contacting portion of said inner surface is 
 clasping said spherical portion of said caput femur replacement, such that said caput femur replacement is restrained in said bowl shaped inner surface. 
 
     
     
         43 . The method according to  claim 42 , wherein
 said inner surface comprising an equator line being the largest circular circumference of said inner contacting surface, wherein said at least one extending portion is passing beyond said equator line, such that the end portion of said contacting portion of said inner surface forms a circular extension line having a parallel smaller circumference than said equator line, the end portion being the most distal portion of the inner surface being in contact with said caput femur or artificial replacement therefore, placing said caput femur or artificial replacement therefore symmetrically in said inner surface, and wherein said at least one extending portion is extending circumferentially discontinuously along said equator line, wherein said caput femur replacement is extending into an elongated member, the method involves, placing a portion of said elongated member between said extension line and said equator line when moving said caput femur or artificial replacement therefore in relation to said inner surface.   
     
     
         44 . The method according to  claim 43 , comprising a prosthetic caput femur being ball shaped and adapted to be at least partly placed inside said inner surface, being bowl shaped, wherein said at least one extending portion is mounted according to at least one of the following alternatives:
 a) extending circumferentially discontinuously along said equator line having enough circumferential distance lacking any extending portion and b) extending with different distal extension in different extending portions or part of such portion of said circumferential extension.   
     
     
         45 . The method according to  claim 40 , for implantation in a hip joint according to any of the preceding claims, comprising a locking member for locking an artificial replacement of an acetabulum in a hip joint to clasp a caput femur or an artificial replacement therefore, when implanted in a hip joint of a patient, wherein said locking member is adapted to in situ assist in the fixation of the medical device, said artificial acetabulum comprising an inner surface comprising an equator line, being the largest circular circumference of said inner surface, wherein at least one extending portion of said inner surface passes beyond said equator line, such that the end portion of a contacting portion of said inner surface, the most distal portion of said inner surface adapted to contact a caput femur or artificial caput femur forms a circular extension line parallel to said equator line having a smaller circumference than said equator line, when the inner surface is placed symmetrically onto the prosthetic caput femur, wherein the method comprising the following steps:
 b) cutting the skin in the hip region   c) dissecting the hip joint   d) implanting the medical device in a hip joint of a patient,   e) fixating the artificial replacement of an acetabulum to the femoral bone of the patient, comprising an inner and an outer surface, having a contacting portion of said inner surface being spherical and bowl shaped   f) facing the inner surface to the center of the hip joint having at least one extending portion, extending a contacting portion for contacting the caput femur or a prosthetic replacement therefore,   g) placing a caput femur or an artificial replacement therefore to the pelvic bone having a spherical portion, such that said extending contacting portion of said inner surface is   h) clasping said spherical portion of said caput femur, or an artificial replacement therefore,   i) placing said locking member such that said caput femur, or artificial replacement therefore is restrained in said bowl shaped inner surface, and   j) locking said caput femur or artificial caput femur in said clasped and restrained position in said inner surface, by   k) fixating radially at least the end portion of the at least one extension portion within said circular extension line.