Experiments by G. Ullmark
In an in vitro study Dr Ullmark cemented a cup in a model with impacted corticocancellous bone graft obtained from the Howex bonemill (Barrel 1) and compared it with graft from another bonemill (X). Excentric pressure applied on the cup (Fig. 1 & 2). The result was that bone chips from the Howex bonemill gave the best fixation of the cup and more force had to be applied to rotate (loosen) the cemented cup (Fig 2 & 3).
 
Fig 1
Fig 2
 
 
Fig 3 Load for cup rotation 30 degrees
 
 
Impacted corticocancellous allografts - Recoil and strength
Ullmark G, Nilsson O. JOURNAL OF ARTHROPLASTY 14 (8): 1019-1023 DEC 1999.

Bigger size and defatting of bone chips will increase cup stability
Ullmark G. ARCHIVES OF ORTHOPAEDIC AND TRAUMA SURG. 120 (7-8): 445-447, 2000.


 
Howex AB 2009