Cancellous constructs, cartilage particles and combinations of cancellous constructs and cartilage particles

Abstract

Constructs that are at least partially constructed of allograft cancellous bone are disclosed, along with cartilage particles that may be used with the constructs for repairing articular cartilage defects. A multi-piece construct includes a base member, a cap member and at least one pin that secures the cap member to the base member. The base member may be constructed of mineralized cancellous bone, and is used to replace the subchondral bone removed when a surgeon cuts a bore in the area of an adjacent cartilage defect. The base member includes a blind bore and first and second through-going transverse bores in opposite sides of a wall of the base member. The cap member includes an upper section that has a thickness that is similar to that of a patient's surrounding articular cartilage layer and a stem depending from the upper section that is dimensioned to be received in and by the blind bore of the base member. The stem includes a transverse through-going bore, which may be aligned with the transverse through-going bores of the base member to receive the pin therein when the construct has been assembled. The cap member is at least partially formed of demineralized allograft cancellous bone, into which a mixture containing lyophilized, freeze-milled allograft cartilage particles may be infused for the repair of articular cartilage defects. The cartilage particles have a size within a range of from about 10 microns to about 210 microns.

1 . A cartilage defect repair material, comprising freeze-milled allograft cartilage particles having a size within a range of from about 10 microns to about 210 microns. 
     
     
         2 . The cartilage defect repair material as claimed in  claim 1 , wherein said cartilage particles are mixed with a biocompatible carrier, so as to form a mixture. 
     
     
         3 . The cartilage defect repair material as claimed in  claim 2 , wherein said biocompatible carrier is a bioabsorbable carrier. 
     
     
         4 . The cartilage defect repair material as claimed in  claim 2 , wherein said mixture includes an additive selected from the group consisting of a growth factor, human demineralized bone matrix, insulin, insulin-like growth factor-1, interleukin-1 receptor agonist, hepatocyte growth factor, platelet-derived growth factor, Indian hedgehog, transformative growth factor and parathyroid hormone-related peptide. 
     
     
         5 . The cartilage defect repair material as claimed in  claim 1 , wherein said cartilage particles have a mean equivalent spherical diameter of about 26 microns. 
     
     
         6 . The cartilage defect repair material as claimed in  claim 1 , wherein said cartilage particles are devitalized. 
     
     
         7 . The cartilage defect repair material as claimed in  claim 1 , wherein said cartilage particles are formed from allograft cartilage that has been lyophilized. 
     
     
         8 . The cartilage defect repair material as claimed in  claim 7 , wherein said cartilage particles are formed by freeze-milling allograft cartilage subsequent to lyophilization. 
     
     
         9 . The cartilage defect repair material as claimed in  claim 7 , wherein said cartilage particles are formed from allograft cartilage that has been lyophilized so as to reduce its water content to an amount within the range of from about 0.1% to about 8.0% by weight. 
     
     
         10 . The cartilage defect repair material as claimed in  claim 1 , wherein said cartilage particles have an aspect ratio of about 1.57. 
     
     
         11 . The cartilage defect repair material as claimed in  claim 1 , wherein said cartilage defect repair material is sterile. 
     
     
         12 . A cartilage defect repair material, comprising allograft cartilage particles having a size ranging from 0.01 mm to 0.21 mm.