Limb lengthener

Abstract

A bone distraction device and a method for installing and using the bone distraction device are disclosed. Separated portions of a bone may be coupled to two or more mounts of the bone distraction device. Each portion of the bone may be coupled to at least one mount. The mounts may be contoured in arcs of at least π/3 radians to accommodate the circumference of the bone. The bone distraction device may include three or more guide rods coupled to the mounts. A distractor may be used to move one mount relative to one or more other mounts to distract the bone portions. In one embodiment, one mount may be coupled to a transport segment of bone for transport distraction between two bone segments. In some embodiments, a hydraulic bone distractor may be used to distract the bone portions.

1 . A bone distraction device, comprising:
 a hydraulic housing configured to be coupled to a first portion of a bone;   a first mount configured to be coupled to a second portion of the bone; and   a piston at least partially enclosed in the hydraulic housing, wherein the piston is configured to be coupled to the mount, and wherein the piston is further configured to move relative to the hydraulic housing such that the second portion of the bone is distracted from the first portion of the bone during use.   
     
     
         2 . The device of  claim 1 , further comprising one or more seals configured to substantially surround a portion of the piston enclosed in the hydraulic housing, wherein the one or more seals are configured to inhibit hydraulic fluid from escaping the hydraulic housing during use. 
     
     
         3 . The device of  claim 2 , wherein the one or more seals are configured to stabilize the piston during use. 
     
     
         4 . The device of  claim 1 , further comprising a second mount coupled to the hydraulic housing, wherein the second mount is configured to couple the hydraulic housing to the first portion of the bone. 
     
     
         5 . The device of  claim 1 , further comprising a pump coupled to the hydraulic housing, wherein the pump is configured to provide hydraulic fluid into the hydraulic housing during use in order to move the piston relative to the hydraulic housing. 
     
     
         6 . The device of  claim 5 , further comprising a valve coupled to the pump, wherein the valve is configured to inhibit backflow of hydraulic fluid towards the pump during use. 
     
     
         7 . The device of  claim 6 , wherein the valve is placed in the hydraulic housing. 
     
     
         8 . The device of  claim 6 , wherein the hydraulic fluid comprises saline fluid. 
     
     
         9 . The device of  claim 6 , wherein the pump is placed subcutaneously. 
     
     
         10 . The device of  claim 1 , further comprising a bleed valve coupled to the hydraulic housing. 
     
     
         11 . The device of  claim 1 , wherein the first mount is contoured in an arc of at least π/3 radians to accommodate the circumference of the bone. 
     
     
         12 . The device of  claim 1 , wherein the hydraulic housing is contoured in an arc of at least π/3 radians to accommodate the circumference of the bone. 
     
     
         13 . The device of  claim 1 , wherein the device comprises bioabsorbable materials. 
     
     
         14 . The device of  claim 1 , wherein the first mount comprises one or more plates. 
     
     
         15 . The device of  claim 1 , further comprising:
 two or more guide rods, wherein a first end of each guide rod is coupled to the hydraulic housing, and wherein each of the guide rods is coupled to the first mount.   
     
     
         16 . A bone distraction device, comprising:
 a hydraulic housing configured to be coupled to a first portion of a bone;   an intermediate hydraulic cylinder at least partially enclosed in the hydraulic housing, wherein the intermediate hydraulic cylinder is configured to move relative to the hydraulic housing during use;   a first mount configured to be coupled to a second portion of bone; and   a piston at least partially enclosed in the intermediate hydraulic cylinder, wherein the piston is configured to be coupled to the first mount, and wherein the piston is further configured to move relative to the intermediate hydraulic cylinder and the hydraulic housing such that the second portion of the bone is distracted from the first portion of the bone during use.   
     
     
         17 . The device of  claim 16 , further comprising one or more seals configured to substantially surround a portion of the piston enclosed in the intermediate hydraulic cylinder, and one or more seals configured to substantially surround a portion of the intermediate hydraulic cylinder enclosed in the hydraulic housing. 
     
     
         18 . The device of  claim 16 , further comprising a second mount coupled to the hydraulic housing, wherein the second mount is configured to couple the hydraulic housing to the first portion of the bone. 
     
     
         19 . The device of  claim 16 , further comprising a pump coupled to the hydraulic housing, wherein the pump is configured to provide hydraulic fluid into the hydraulic housing during use. 
     
     
         20 . The device of  claim 16 , wherein the hydraulic housing and the first mount are contoured in an arc of at least π/3 radians to accommodate the circumference of the bone. 
     
     
         21 . The device of  claim 16 , further comprising:
 two or more guide rods, wherein a first end of each guide rod is coupled to the hydraulic housing, and wherein each of the guide rods is coupled to the first mount.   
     
     
         22 . A method of lengthening a bone, comprising:
 making an osteotomy in a bone to form a first portion of the bone and a second portion of the bone; and   separating the second portion of the bone from the first portion of the bone using a distraction device coupled to the bone, the distraction device comprising a piston coupled to the second portion of the bone configured to move relative to a hydraulic housing coupled to the first portion of the bone.