Evaluation of Demineralized Bone Matrix (DBM) and Bone Marrow for Repair of Femoral Defects in Dogs

Recipient Organization
TUFTS UNIVERSITY
200 WESTBORO ROAD
N. GRAFTON,MA 01536

Performing Department
CLINICAL SCIENCES

Non Technical Summary
The healing of bone is a complex process and differs between species. Because bone is a tissue responsible for mechanical support, its qualities differ primarily due to the species size. Differences in bone and bone healing are also contingent upon the nutritional patterns of the species, such as herbivores vs carnivores and omnivores. The purpose of this study is to assess how the healing of bone fractures can be accelerated by the addition on demineralized bone and bone marrow to the fracture site.

Animal Health Component

50%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
311	3830	1020	100%

Knowledge Area
311 - Animal Diseases;

Subject Of Investigation
3830 - Pets (companion animals);

Field Of Science
1020 - Physiology;

Keywords

Goals / Objectives
Techniques have been discovered to enrich mesenchymal stem cells (MSCs) from fresh bone marrow and combine them with improved graft materials intraoperatively. This study is designed to discern the contribution of the MSCs, the graft matrix material, and the precise formulation of the composite with additional marrow or platelet concentrates. These results should have a direct and immediate impact on the design of therapeutic products for human bone grafting.

Project Methods
Seven groups of test animals will have femoral defects created and treated with different combinations of DBM and MSCs, along with other biological materials. The effect of these treatments will be assessed by radiography, CT, and histology.

Progress 11/01/02 to 06/30/04

Outputs
A 21mm defect was created in one femoral diaphysis of 4 dogs. Periosteum as well as a cylinder of bone was removed, and the defect stabilized with a bone plate. The defect was filled with Cellect and Healos. Cranial to caudal radiographs were taken post-operatively and every four weeks for 16 weeks. The radiographs were evaluated for healing using two ordinal scales. At 16 weeks, the dogs were euthanized and the femurs harvested and shipped to another institution for computed tomography and histologic evaluation. All dogs tolerated the procedure well, and were using the operated limb without discernable lameness by 14 days postoperatively. One dog (#084) was injured at 8 weeks into the study and became persistently lame thereafter. Radiographic evaluation showed that an atrophic non-union occurred in two dogs (#524, #699). The femur of the dog that was injured (#084) demonstrated new bone growth, but instability and oligotrophic non-union. Grossly and radiographically the femur, plate and surgical area appeared infected. A fourth dog had bone union (#845). The formulation used resulted in poor bone regeneration in this model.

Impacts
The significance of this study is that a presumably favorable carrier material for stem cell regeneration of bone was not effective and resulted in delayed bone regeneration.

Publications

No publications reported this period