Bone growth device and method

Abstract

An intramedullary lengthening device includes a housing and a distraction shaft. The intramedullary lengthening device is placed within a cavity of two bone sections (either already separated or purposely separated for insertion of the device). The distraction shaft of the intramedullary lengthening device is attached to the one of the bone sections using, for example, one or more attachment screws. The housing of the intramedullary lengthening device is attached to the second bone section using, for instance, one or more attachment screws. Over the treatment period, the bone is continually distracted, creating a new separation into which osteogenesis can occur. In one embodiment, the intramedullary lengthening device includes an actuator and an extension rod, which can be attached to one other.

1 .- 25 . (canceled) 
     
     
         26 . An external adjustment device for adjusting an adjustable implant comprising:
 a power supply;   a control module;   a handheld device comprising at least one permanent magnet;   wherein the handheld device is configured to be placed on a first side of a patient's limb;   wherein the at least one permanent magnet is configured to turn a cylindrical magnet located inside the adjustable implant; and   wherein the control module is configured to restrict the number of turns of the cylindrical magnet located inside the adjustable implant.   
     
     
         27 . The external adjustment device of  claim 26 , wherein access to the control module is restricted through a security code. 
     
     
         28 . The external adjustment device of  claim 26 , wherein the control module is configured to monitor movement of one or both of the at least one permanent magnet of the handheld device or the cylindrical magnet located inside the adjustable implant. 
     
     
         29 . The external adjustment device of  claim 28 , wherein the control module is configured to rotate the at least one permanent magnet at a rotational speed of 60 RPM or less. 
     
     
         30 . The external adjustment device of  claim 26 , wherein the control module is configured to rotate the at least one permanent magnet at a rotational speed that maintains the tissue and fluids of the patient at a current density of 0.04 Amperes per meters squared or less. 
     
     
         31 . The external adjustment device of  claim 26 , wherein the handheld device is configured to maintain a magnetic field strength of 2.0 Tesla or less within the tissue and fluids of the patient. 
     
     
         32 . The external adjustment device of  claim 26 , wherein operation of the external adjustment device in a first manner causes the at least one permanent magnet to turn in a first direction and to thereby effectuate an increase of a length of the adjustable implant, and wherein the control module is configured to limit a rate of increase of the length of the adjustable implant to two millimeters per day or less. 
     
     
         33 . The external adjustment device of  claim 32 , wherein the control module is configured to limit the rate of increase of the length of the adjustable implant to one millimeter per day or less. 
     
     
         34 . The external adjustment device of  claim 26 , wherein operation of the external adjustment device in a first manner causes the at least one permanent magnet to turn in a first direction and to thereby effectuate an increase of a length of the adjustable implant, and wherein the control module is configured to limit a rate of increase of the length of the adjustable implant to one-half millimeter or less over a two hour period. 
     
     
         35 . An external adjustment device for adjusting an adjustable implant disposed on or within a patient's limb comprising:
 a power supply;   a control module;   at least one permanent magnet disposed within the external adjustment device and configured to rotate in response to instructions from the control module and turn a radially poled magnet located inside the adjustable implant; and   wherein the control module is configured to restrict the number of turns of the radially poled magnet located inside the adjustable implant.   
     
     
         36 . The external adjustment device of  claim 35 , wherein access to the control module is restricted through a security code. 
     
     
         37 . The external adjustment device of  claim 35 , wherein the control module is configured to monitor movement of one or both of the at least one permanent magnet of the external adjustment device and the radially poled magnet located inside the adjustable implant. 
     
     
         38 . The external adjustment device of  claim 37 , wherein the control module is configured to rotate the at least one permanent magnet at a rotational speed of 60 RPM or less. 
     
     
         39 . The external adjustment device of  claim 35 , wherein the control module is configured to rotate the at least one permanent magnet at a rotational speed that maintains the tissue and fluids of the patient at a current density of 0.04 Amperes per meters squared or less. 
     
     
         40 . The external adjustment device of  claim 35 , wherein the external adjustment device is configured to maintain a magnetic field strength of 2.0 Tesla or less within the tissue and fluids of the patient when placed on at least a first side of the patient's limb. 
     
     
         41 . The external adjustment device of  claim 35 , wherein operation of the external adjustment device in a first manner causes the at least one permanent magnet to turn in a first direction and to thereby effectuate an increase of a length of the adjustable implant, and wherein the control module is configured to limit a rate of increase of the length of the adjustable implant to two millimeters per day or less. 
     
     
         42 . The external adjustment device of  claim 41 , wherein the control module is configured to limit the rate of increase of the length of the adjustable implant to one millimeter per day or less. 
     
     
         43 . The external adjustment device of  claim 35 , wherein operation of the external adjustment device in a first manner causes the at least one permanent magnet to turn in a first direction and to thereby effectuate an increase of a length of the adjustable implant, and wherein the control module is configured to limit a rate of increase of the length of the adjustable implant to one-half millimeter or less over a two hour period. 
     
     
         44 . A method for limiting the lengthening rate of a bone of a patient, the method comprising:
 providing an adjustable implant having a first end and a second end and configured for implantation within the patient, the adjustable implant comprising a rotatable magnet, wherein the rotation of the rotatable magnet in a first direction causes the adjustable implant to increase in length;   providing an external adjustment device comprising a power supply, a control module, and at least one permanent magnet configured for rotation in response to instructions from the control module, the external adjustment device configured to non-invasively adjust the length of the adjustable implant;   securing the first end of the adjustable implant to a first portion of the bone;   securing the second end of the adjustable implant to a second portion of the bone;   accessing the control module by use of a security code;   inputting into the control module at least one limit selected from the group consisting of: a maximum allowable length change per day, a maximum allowable length change per hour, or a maximum allowable rate of length change of the adjustable implant; and   increasing the length of the adjustable implant within the selected limit.   
     
     
         45 . The method of  claim 44 , wherein the inputting operation limits a rate of increase of the length of the adjustable implant to two millimeters per day or less. 
     
     
         46 . The method of  claim 45 , wherein the inputting operation limits the rate of increase of the length of the adjustable implant to one millimeter per day or less. 
     
     
         47 . The method of  claim 44 , wherein the inputting operation limits a rate of increase of the length of the adjustable implant to one-half millimeter or less over a two hour period. 
     
     
         48 . The method of  claim 44 , wherein the inputting operation limits a rate of increase of the length of the adjustable implant to one-quarter millimeter or less over a five minute period. 
     
     
         49 . The method of  claim 44 , wherein the control module is configured to rotate the at least one permanent magnet at a rotational speed of 60 RPM or less.