Factors affecting stiffness properties in impacted morsellized bone used in revision hip surgery: An experimental in vitro study

Abstract

When revising loosened joint prosthesis, impacted morsellized bone is frequently used as organic scaffolding. We studied the relative influence that different bone particle size, impaction energy, and liquid content had on impacted bone stiffness. Bovine bone was morsellized in a bone mill by three grinding drums to produce bone with different chip size distribution. Next, portions of bone chips of controlled sizes were produced by a five-leveled sieve. Layer by layer of bone are constructed into pellets by our experimental impaction method. This method allows us to vary one independent factor at a time in a controlled manner while keeping the other factors constant. Stiffness for all bone pellets were measured during impaction and loading. In earlier studies, we focused on how impaction force, number of impaction strokes, and bone liquid contents influence mechanical behavior. Here, we compare the outcome of all studies using general linear models. All five factors significantly contribute to stiffness of impacted morsellized bone. Changing bone moisture has major, while increasing the number of impaction strokes beyond five per layer has minor effect. Low water content is the main contributor to highest load stiffness. Optimal stability of impacted morsellized bone is achieved with dried and well-graded particles. The number of heavy impaction strokes can be restricted.

Bone healing of severe acetabular defects after revision arthroplasty

“…Those impactors are equipped with a microstructure to enhance hard impaction (Figure 4). There are also several small holes for evacuation of liquid to produce a more stable graft bed (Fosse et al 2006). This structure of the impactor may enhance the containment of a blood clot within the graft layer.…”

The stability of impacted morsellized bone grafts in a metal cage under dynamic loaded conditions: an in vitro reconstruction of a segmental diaphyseal bone defect

“…The bovine bone used in this study has diVerent properties compared to human bone. The stiVness however is in the same range and is mainly inXuenced by impaction, particle size and water content [2,14].…”

Impaction bone grafting in revision hip surgery: past, present and future

“…However, in an attempt to achieve graft compaction there may be complications such as femoral fracture, and over compaction, which may decrease the graft microporosity and subsequent revascularization. On the basis of research so far, the use of large particles, possibly in a well graded mixture; fat and soft tissue removal; and appropriate compaction force are all strategies, as described above, that can be used to improve graft quality and decrease the risk of complications (Tagil and Aspenberg 1998;Bavadekar et al 2001;Fosse et al 2004Fosse et al , 2006a.…”