Effects of a magnesium adhesive cement on bone stability and healing following a metatarsal osteotomy in horses.
OBJECTIVE
To compare biodegradable magnesium phosphate cement (Mg-cement), calcium phosphate cement (Ca-cement), and no cement on bone repair, biocompatibility, and bone adhesive characteristics in vivo in horses.


METHODS
8 clinically normal adult horses.


METHODS
Triangular fragments (1-cm-long arms) were created by Y-shaped osteotomy of the second and fourth metatarsal bones (MTII and MTIV, respectively). Fragments were replaced in pairs to compare Mg-cement (MTII, n = 8; MTIV, 8) with Ca-cement (MTIV, 8) or with no cement (MTII, 8). Clinical and radiographic evaluations were performed for 7 weeks, at which time osteotomy sites were harvested for computed tomographic measurement of bone density and callus amount, 3-point mechanical testing, and histologic evaluation of healing pattern and biodegradation.


RESULTS
All horses tolerated the procedure without clinical problems. Radiographically, Mg-cement secured fragments significantly closer to parent bone, compared with Ca-cement or no treatment. Callus amount and bone remodeling and healing were significantly greater with Mg-cement, compared with Ca-cement or no cement. Biomechanical testing results and callus density among treatments were not significantly different. Significantly greater woven bone was observed adjacent to the Mg-cement without foreign body reaction, compared with Ca-cement or no cement. The Mg-cement was not fully degraded and was still adhered to the fragment.


CONCLUSIONS
Both bone cements were biocompatible in horses, and Mg-cement may assist fracture repair by osteogenesis and fragment stabilization. Further studies are warranted on other applications and to define degradation characteristics.
Waselau
Martin
M
Comparative Orthopaedic Research Laboratory, Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH 43210, USA.
Samii
Valerie F
VF
Weisbrode
Steven E
SE
Litsky
Alan S
AS
Bertone
Alicia L
AL
D000818:Animals; D001843:Bone Cements / Q000627:therapeutic use*; D002130:Calcium Phosphates / Q000627:therapeutic use*; D006736:Horses / Q000601:surgery*; D017616:Magnesium Compounds / Q000627:therapeutic use*; D008422:Materials Testing / Q000662:veterinary; D008682:Metatarsal Bones / Q000000981:diagnostic imaging / Q000601:surgery*; D010027:Osteotomy / Q000379:methods / Q000662:veterinary*; D010710:Phosphates / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed / Q000662:veterinary; D016896:Treatment Outcome; D014945:Wound Healing / Q000187:drug effects
D001843:Bone Cements; D002130:Calcium Phosphates; D017616:Magnesium Compounds; D010710:Phosphates; C030781:magnesium phosphate; C020243:calcium phosphate