Method and Apparatus For Force Redistribution in Articular Joints

Abstract

Pathologies of joints arising from improper force distributions are addressed by displacement of targeted connective and muscle tissues surrounding the joint in order to realign force vectors and alter moment arms loading the joint.

What is claimed is: 
     
         1 . An apparatus for treating human hip joint, said hip joint including at least a femur and a pelvis with a facing articular surface, the femur and pelvis being subject to forces exerted by target tissues around said hip joint, the apparatus comprising:
 a support portion configured and dimensioned to be secured at least adjacent the proximal femur, including means for facilitating fixation to the femur or said tissues; and   a bearing portion supported by the support portion, the bearing portion being configured and dimensioned for placement proximate a target tissue acting between the femur and pelvis to displace said target tissue relative to a natural path of the target tissue by a distance sufficient to redirect a force exerted by said target tissue on said hip joint to achieve a therapeutic effect, said bearing portion having at least one bearing surface configured to atraumatically engage the target tissue.   
     
     
         2 . The apparatus of  claim 1 , wherein:
 the bearing portion is configured and dimensioned to be received on a portion of the greater trochanter; and   the support portion includes a first part configured and dimensioned to extend anteriorly from the bearing portion between the attachments for the  piriformis  and gluteus minimus, and a second part configured and dimensioned to extend posteriorly between the attachments for the quadrates femoris and the iliopsoas.   
     
     
         3 . The apparatus of  claim 1 , wherein the support portion at least in part underlies the bearing portion and comprises a support surface opposite the bearing surface adapted to contact underlying tissue. 
     
     
         4 . The apparatus of  claim 3 , wherein the support surface is adapted to contact at least one of the femur and pelvis. 
     
     
         5 . The apparatus of  claim 1 , wherein the support portion and bearing portion are configured to displace the target tissue from its natural path by about 10 to about 30 mm. 
     
     
         6 . The apparatus of  claim 1 , wherein:
 the bearing portion is comprised of a superior section of the implant, having an upper side and a lower side, and including a bearing member with said bearing surface on the upper side configured to displace said target tissue, and a bone engaging surface on the lower side configured to engage a lateral-lateral/superior surface of the greater trochanter; and   the support portion is comprised of an anterior section extending from the superior section lower side along an anterior portion thereof and having an inner bone engaging surface, and a posterior section extending from the superior section lower side along a posterior portion thereof and having an inner bone engaging surface.   
     
     
         7 . The apparatus of  claim 6 , wherein the posterior section bone engaging surface substantially faces the anterior section bone engaging surface. 
     
     
         8 . The apparatus of  claim 6 , wherein said anterior and posterior section inner bone engaging surfaces are each generally perpendicular to the superior section bone engaging surface. 
     
     
         9 . The apparatus of  claim 6 , wherein the anterior section is configured and dimensioned specifically to avoid the gluteus minimus, piriformis, and obturator internus and superior and inferior gemellus, and to be fixed to an anterior surface of the proximal femur with the bone engaging surface of the superior section disposed at least in part against the greater trochanter. 
     
     
         10 . The apparatus of  claim 6 , wherein the posterior section is configured and dimensioned specifically to avoid the quadratus femoris and the iliopsoas, and to be fixed to a posterior surface of the proximal femur with the bone engaging surface of the superior section disposed at least in part against the greater trochanter. 
     
     
         11 . The apparatus of  claim 6 , wherein said implant is configured and dimensioned to be secured to the proximal femur outside of the hip joint capsule. 
     
     
         12 . The apparatus of  claim 6 , wherein the superior section is configured and dimensioned to position the bearing surface to displace the hip abductor circumferentially with respect to the hip joint. 
     
     
         13 . The apparatus of  claim 1 , wherein the joint is surrounded by a capsule, and wherein the means for facilitating fixation is configured for fastening to soft tissue or bone outside of the capsule. 
     
     
         14 . The apparatus of  claim 1 , wherein said apparatus comprises a prosthesis formed of at least two interlocking parts configured to be assembled in situ. 
     
     
         15 . An implant for treating conditions in the human hip, said implant configured and dimensioned to be secured to the proximal femur to displace at least one muscle or connective tissue of the hip from a natural path to a therapeutic path, said muscle or connective tissue comprising target tissues for treatment, said implant comprising:
 a superior section, having an upper side and a lower side, including a bearing member with a smooth, continuous bearing surface on the upper side configured to displace said target tissue, and a bone engaging surface on the lower side configured to engage a lateral-lateral/superior surface of the greater trochanter;   an anterior section extending from the superior section lower side along an anterior portion thereof and having an inner bone engaging surface; and   a posterior section extending from the superior section lower side along a posterior portion thereof and having an inner bone engaging surface.   
     
     
         16 . The implant of  claim 15 , wherein said anterior and posterior section inner bone engaging surfaces are each generally perpendicular to the superior section bone engaging surface. 
     
     
         17 . The implant of  claim 15 , wherein the implant comprises at least two interlocking units. 
     
     
         18 . The implant of  claim 15 , wherein the anterior section is configured and dimensioned to be fixed to an anterior surface of the proximal femur with the bone engaging surface of the superior section disposed at least in part against the greater trochanter while avoiding the gluteus minimus, piriformis, and obturator internus and superior and inferior gemellus. 
     
     
         19 . The implant of  claim 15 , wherein the posterior section is configured and dimensioned to be fixed to a posterior surface of the proximal femur with the bone engaging surface of the superior section disposed at least in part against the greater trochanter while avoiding the quadratus femoris and the iliopsoas. 
     
     
         20 . The implant of  claim 20 , wherein said implant is configured and dimensioned to be secured to the proximal femur outside of the hip joint capsule. 
     
     
         21 . A method of treating a human hip joint to effect force distribution in the joint, said hip joint surrounded by a joint capsule and including femur and acetabulum bones with facing articular surfaces, the bones being positioned with respect to one another by associated muscle and connective tissues, the method comprising:
 selecting at least one of said associated muscle and connective tissues as target tissue for treatment;   securing an implant to at least one said bone proximate the hip joint;   displacing said target tissue with said implant without severing said bones; and   redistributing loading in the joint with said displacing to achieve a therapeutic effect in the joint.   
     
     
         22 . The method of  claim 21 , wherein said securing an implant comprises: positioning the implant on a first side of the hip joint without penetrating the joint capsule to displace said target tissue relative to said joint, wherein a resultant force exerted by said target tissue on the hip joint is redirected in a manner to redistribute a load on at least one of said articular surfaces without cutting the bones of the joint, and wherein the force exerted by the target tissue is moved away from said first side. 
     
     
         23 . The method of  claim 21 , wherein said placing comprises placing the implant outside the joint capsule between the joint capsule and at least a portion of the hip abductor muscles. 
     
     
         24 . The method of  claim 21 , wherein natural force exerted by the target tissue acts on the hip joint through an effective moment arm, and displacing the target tissue moves the target tissue to a position wherein the effective moment arm is increased. 
     
     
         25 . The method of  claim 21 , wherein the target tissue is at least one of an abductor muscle, the gluteus minimus, the gluteus medius, or the gluteus maximus.