Effect of recombinant human bone morphogenetic protein 2 (rhBMP-2) on equine bone formation: A preliminary in vitro and in vivo evaluation

Abstract

Summary: Bone morphogenetic protein 2 (BMP-2) is a potent inducer of osteoblast-mediated bone formation and is used in orthopaedic applications in humans. This study was performed to evaluate (1) recombinant human BMP-2 (rhBMP-2) in clinical cases of subchondral cystic lesion (SCL) in horses and (2) the osteoinductive effects of rhBMP-2 treatment in vitro on primary equine osteoblasts. Three horses with SCLs of the proximal interphalangeal (PIP) joint and associated lameness were treated by transcortical debridement and implantation of a collagen sponge containing rhBMP-2. In the in vitro studies, equine osteoblasts were cultured with rhBMP-2 to assess the effects of rhBMP-2 on their differentiation and mineralization. The treatment of SCLs with rhBMP-2 was well tolerated by all the horses, and improvements in subchondral bone radiographic appearance and lameness score were evident between 7 and 10 months post-surgery. Equine osteoblasts treated with rhBMP-2 demonstrated enhanced mineralization as evidenced by increases in Alizarin Red S staining. This was accompanied by significant increases in alkaline phosphatase (ALP) expression and activity, and a significant decrease in secreted osteocalcin levels. In conclusion rhBMP-2 can be used to assist in subchondral bone repair in horses, and we provide in vitro evidence to suggest that its influence on bone formation is mediated through enhanced osteoblast activity.

Use of an aiming device and computed tomography for assisted debridement of subchondral cystic lesions in the limbs of horses

“…There has been an increase in the use of computer‐assisted surgery in horses to guide fracture repair, particularly within the hoof . However, only a few studies have described the use of CT to assist surgical procedures in horses . One study used CT to guide orthopedic surgery in 86 horses, including 2 cases of SCL in the distal limb in which CT enabled localization of the cyst and injection of steroids .…”

“…After thorough debridement of the cystic cavity, the lesions were filled with collagen sponges preloaded with 0.5 mg/mL rhBMP‐2 to promote bone regeneration. The effect of rhBMP‐2 was evaluated in a study of 3 horses with 5 SCL in the pastern joint; all 3 horses had a successful outcome, and the treatment was well tolerated …”

“…However, most SCL in the distal limbs are not accessible via arthroscopy and require a more technically demanding transcortical approach for debridement . The latter technique allows preservation of the cartilage overlying the SCL …”

“…During the past decade, there has been an increase in the use of 3D imaging modalities to guide orthopedic surgery in horses . Computed tomography has been used to localize SCL in the distal limb and to guide the injection of steroids into the lesions as well as to assist in the debridement and filling of SCL of the carpus and limbs of horses . Radiopaque markers such as barium sulfate paste or radiopaque tubular drain that is glued in place with cyanoacrylate have been used to identify anatomical landmarks when planning surgery involving CT.…”

„Echte“ Lahmheit oder Blockade? Ein Fallbericht

“…Durch ihr Lumen üben sie vermehrt Druck auf das umliegende Knochen-und Knorpelgewebe aus, was zu starken Schmerzen führen kann. Neuere Forschungen versuchen die Osteoblasten mit knochenmorphogenetischen Proteinen (Bone Morphogenetic Proteins, BMP) zu aktivieren, damit sich der Hohlraum nach der Kürettage mit körpereigenem Knochenmaterial füllen kann [2].…”