An evaluation of the effect on lower extremity fracture healing of collagen-based fusion material containing 2 different calcium phosphate salts: An experimental rat model

Adv Clin Exp Med. 2018 Sep;27(9):1295-1301. doi: 10.17219/acem/90766.


Background: Collagen-based synthetic bone grafts which contain tricalcium phosphate (TCP) and hydroxyapatite (HA), and collagen-based synthetic bone grafts containing only TCP have some advantages compared to autografts. Therefore, these grafts are frequently used to fill bone defects and pseudoarthrosis.

Objectives: The aim of this study was to evaluate and compare the clinical, radiological and histopathological effects of TCP-HA and TCP alone + Type-1 collagen in healing lower extremity fractures in a pseudoarthrosis model in rat femurs.

Material and methods: A total of 36 female Wistar rats were randomly separated into 4 groups. Group 1 (n = 10) was the control group. A femur pseudoarthrosis model was created in Groups 2, 3 and 4. On the 90th day after the 1st surgery in Group 2 (n = 10), TCP-HA + Type-1 collagen was applied, in Group 3 (n = 10), TCP alone + type-1 collagen was applied, and in Group 4 (n = 6, the placebo group), saline solution was applied. Fixation was performed with an intramedullar pin. After 60 days and clinical and radiological scoring, all animals were sacrificed and a histopathological evaluation of the pseudoarthrosis areas was conducted.

Results: In all the clinical, radiological and histopathological measurements used in the evaluations of the differences between the groups, a higher rate of union was determined in Group 2 (TCP-HA). No significant difference was determined between Group 3 and Group 4 in terms of union rates.

Conclusions: The clinical, radiological and histopathological results of this study showed that TCP alone was less effective than TCP-HA in the union of a femur pseudoarthrosis model in rats. The reason for this difference was considered to be hydroxyapatite (HA).

Keywords: bone healing; collagen; pseudoarthrosis; rats; synthetic bone greft.

MeSH terms

  • Animals
  • Bone Substitutes*
  • Calcium
  • Calcium Phosphates / therapeutic use*
  • Collagen / therapeutic use*
  • Female
  • Fracture Healing*
  • Lower Extremity
  • Random Allocation
  • Rats
  • Rats, Wistar
  • Salts*


  • Bone Substitutes
  • Calcium Phosphates
  • Salts
  • Collagen
  • Calcium