Immediate mandibular reconstruction of a 5 cm defect using rhBMP-2 after partial mandibulectomy in a dog

Objective— To report treatment of a complex odontoma of the mandible by partial mandibulectomy and immediate surgical reconstruction using bridging plate fixation with a synthetic graft.
Study Design— Clinical case report.
Animals— A 4-year-old male castrated cocker spaniel.
Methods— Immediate reconstruction of the left mandible (5 cm gap) was performed after complete excision of a complex odontoma. Locking plate fixation was applied immediately before complete excision of the mass. Fixation was removed, then after partial mandibulectomy, including all abnormal tissue, restored to achieve occlusion. The resulting mandibular defect was filled with recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered in an absorbable collagen sponge containing hydroxyapatite/tricalcium phosphate granules (compression resistant matrix [CRM]).
Results— New bone growth was evident radiographically and on palpation at 3 months. Bony remodeling was evident during follow-up examinations up to 26 months. Bone collected by biopsy at the graft site at 7 months had robust new bone formation and evidence of continued remodeling. Only minor complications (repeated intraoral plate exposure) were encountered postoperatively and were easily resolved.
Conclusions— An osteoinductive factor (rhBMP-2/CRM) was successfully used as a graft substitute in immediate reconstruction of a large mandibular defect.
Clinical Relevance— Immediate reconstruction of large mandibular defects with osteoinductive materials as a graft substitute may be a viable alternative to partial mandibular resection or radiation therapy for benign odontogenic tumors in dogs.     

Clinical Use of Recombinant Human Bone Morphogenic Protein-2 in a Whooping Crane (Grus americana)

Objective— To report use of recombinant human bone morphogenetic protein-2 (rhBMP-2) as adjunctive therapy for treatment of a comminuted, open, proximal humeral fracture in an avian species.
Study Design— Clinical report.
Animals— A 3.5-month-old male whooping crane ( Grus americana ).
Methods— An open, severely comminuted humeral facture was stabilized with an intramuscular (IM) pin/type IA external skeletal fixator with tie-in configuration. rhBMP-2 was applied in a calcium phosphate matrix (CPM) paste directly to the fracture site as a bone graft substitute. Radiographic evidence of bone healing was monitored for 14 weeks.
Results— Substantial bony callus was evident at 4 weeks and at 8 weeks there was bridging callus with obvious bony remodeling. The fixation was destabilized at 9 weeks by IM pin removal, bone healing progressed and the fixator was removed at 11 weeks. By 14 weeks both cortices had been re-established with continued callus remodeling evident.
Conclusion— rhBMP-2, applied in a CPM paste, was used as a bone graft substitute in the treatment of a comminuted, open humeral fracture in a whooping crane.
Clinical Relevance— Use of rhBMP-2/CPM should be considered in treatment of avian fractures.     

Repair of a Mandibular Defect With a Free Vascularized Coccygeal Vertebra Transfer in a Dog

Bilateral mandibular defects in a male mongrel dog were repaired. On the left side, a free vascularized coccygeal bone graft that included the median caudal artery and caudal vein was used to correct the defect. On the right side, the defect was bridged with a bone plate and screws. For further immobilization, the muzzle was temporarily taped for 3 weeks and a pharyngostomy tube was used for nutritional support. The dog was able to eat dry commercial food satisfactorily within 2 months of surgery despite mild malocclusion. Radiographs taken 2 months and 18 months postoperatively showed bony union with graft hypertrophy in the left mandible, whereas the right mandibular defect showed protracted nonunion. The results indicate that vascularized coccygeal vertebra transfer provides an alternative for the management of canine mandibular defects.     

Effects of gelatin sponge implantation in cancellous bone defects in dogs

Reports from oral surgeons suggested that packing bone defects with cellulose or collagen stimulated cancellous bone replacement. The study reported here was designed to evaluate a similar method for augmenting the remodeling of cancellous bone defects and graft donor sites. Gelatin sponge was implanted into bony defects created in the proximal humeral metaphysis of 5 adult Beagles after collection of cancellous bone. A similar defect created in the contralateral humerus was left unpacked. Four months after creation of the defect, the dogs were euthanatized, and the surgical sites were evaluated by use of correlated microradiographic and histologic examination. Unpacked sites had filled completely with loosely woven trabecular bone. Remodeling had not taken place in sites packed with gelatin sponge. Gelatin sponge did not elicit any reaction in the surrounding bone, but remained in situ and obstructed new bone formation. Gelatin sponge blocked rather than augmented cancellous bone replacement.     

Evaluation of a free vascularized medial tibial bone graft in dogs

OBJECTIVE: To develop a free vascularized tibial bone graft based on the periosteal saphenous blood supply. STUDY DESIGN: Preliminary anatomic study of medial tibial blood supply. In vivo comparison of a vascularized and avascular tibial bone graft. ANIMALS: Nine canine cadavers; 14 healthy adult dogs that weighed 25 to 32 kg. METHODS: An anatomic study of the vascular supply of the medial aspect of the tibia was performed using the Spalteholz technique. A bone graft consisting of the medial aspect of the tibia was transferred to a mandibular defect as a vascularized graft in 7 dogs and as an avascular graft in 7 dogs. Bone scans were performed to evaluate graft perfusion. Radiographic evaluation of the mandibles and tibias was performed. The dogs were killed after 60 days, five mandibles from each group were examined histologically, and two from each group were evaluated using the Spalteholz technique. RESULTS: The saphenous vascular pedicle provides vascular perfusion to the medial tibial cortex. Bone scans and radiographic evaluations were consistent with viable bone in the vascularized grafts, and nonviable bone in the avascular grafts. Histological examination revealed live, healing bone in vascular grafts and necrotic bone in avascular grafts. Spalteholz evaluation revealed many small arborizing vessels in the vascular grafts and no organized vasculature in the avascular grafts. CONCLUSIONS: The vascularized medial tibial cortical bone graft survived and proceeded to bony union in the mandibular body defect more readily than the avascular graft in this experimental model. CLINICAL RELEVANCE: A vascularized medial tibial bone graft is a suitable free graft for use in reconstructing bone defects in dogs.     

Evaluation of Collagen as a Retainer for Autogenous Cancellous Bone Used in Repair of Full Thickness Cortical Bone Defects

A commercially available collagen sponge acting as a cylindrical retainer containing autogenous cancellous bone graft was proposed for treatment of full thickness cortical defects in dogs. Three groups of three dogs each were subjected to removal of at least 1.5 cm of the tibial diaphyses. All tibias were stabilized with bilateral external fixators. Group 1 received collagen surrounding an autogenous cancellous bone graft. Group 2 received collagen and group 3 received no treatment of the ostectomy site. The collagen sponge appeared to allow vascularization of the bone graft as evidenced by new bone formation and was resorbed by 3 months after implantation. Radiographic, histomorphologic, and histomorphometric evaluation at 3 months after surgery showed a greater per cent of bone in the ostectomy site in group 1.     

野生双峰驼下颌骨的三维重建与应力分析

通过对5个野双峰驼(Camelus bactrianus ferus)下颌骨进行螺旋CT扫描,利用软件Amira 3.1.1对CT扫描图三维重建得到下颌骨三维点云图,并利用Geomagic软件进行实体化,通过有限元分析软件Ansys 14.0对野双峰驼下颌骨角部施加1000 N大小的力后对下颌骨进行有限元分析,得到下颌骨在受力时的应力分布情况:当左下颌角受到水平向右垂直于矢状面的外力时,左下颌角及髁状突颈部极易造成骨折,左颏孔区可能会出现骨裂,而其余部分仅会造成轻微损伤。当右下颌角下缘受到垂直向上垂直于矢状面的外力时,也易出现同样的结果。由此得出结论:当野双峰驼下颌骨角部受到瞬间外力时,应力主要集中在施加力所在骨支的薄弱区域,应力较大部位与骨折易发部位密切相关;且在薄弱区域,下颌角及髁状突颈部的损害最为严重。以上结果有利于深入了解野双峰驼下颌骨应力分布情况,并为骨三维重建在生物学领域的应用提供理论依据。     

Influence of an interdental full pin on stability of an acrylic external fixator for rostral mandibular fractures in dogs

OBJECTIVE: To determine total stiffness and gap stiffness of an external fixation system in a canine mandibular fracture gap model incorporating a full interdental pin as the only point of rostral fixation in a bilateral type-I external fixator. SAMPLE POPULATION: 10 canine mandibles. PROCEDURE: Bilateral mandibular ostectomies were performed between premolars 3 and 4. A type-I external fixator incorporating a full interdental pin was placed to stabilize a 0.5-cm fracture gap. Four pin configurations (intact mandibular bodies with fixator; ostectomized mandibular bodies and complete fixator; ostectomized mandibular bodies with caudal pins of rostral fragment cut; ostectomized mandibular bodies with all pins of rostral fragment cut) were tested in dorsoventral bending 5 times on each mandible. The full interdental pin remained intact in all configurations. Total stiffness and gap stiffness were determined for each configuration on a materials testing machine. RESULTS: Total stiffness of intact mandibles was significantly greater than that of ostectomized mandibles, regardless of external fixator configuration. However, total stiffness and gap stiffness were not significantly different among different external fixator configurations applied to ostectomized mandibles. CONCLUSION AND CLINICAL RELEVANCE: External fixator configurations with only the full interdental pin engaging the rostral fragment were as stiff as configurations that had 2 or 4 additional pins in the rostral fragment for the applied loads. External fixators for rostral mandibular fractures may be rigidly secured with rostral fragment implants applied extracortically, avoiding iatrogenic trauma to teeth and tooth roots.     

Clinical application of recombinant human bone morphogenetic protein-2 in 4 dogs

OBJECTIVE: To describe outcome in dogs with insufficient bone healing treated with recombinant human bone morphogenetic protein-2 (rhBMP-2). STUDY DESIGN: Retrospective study. ANIMALS: Four dogs clinically affected with delayed union or nonunion bone healing. METHODS: Medical records were reviewed for signalment, clinical problem, treatment, and outcome. RESULTS: Four dogs that had delayed- or nonunion of bone fracture, osteotomy, or arthrodesis were treated with either minimally invasive, fluoroscopically guided, percutaneous administration or direct surgical application of rhBMP-2. Doses used ranged from 0.2 to 1.6 mg of rhBMP-2. In 3 dogs, a calcium phosphate matrix (CPM) carrier was used whereas in 1 dog commercially prepared rhBMP-2 impregnated in an absorbable collagen sponge (INFUSE Bone Graft) was used. This latter dog had osteomyelitis associated with implant infection before rhBMP-2 administration. Rapid radiographic union was noted in all dogs with excellent long-term outcome. Adverse effects were minimal and included transient worsening of lameness after percutaneous administration of rhBMP-2 in 2 dogs. CONCLUSIONS: rhBMP-2 stimulated rapid bone formation at delayed- or nonunion sites resulting in radiographic bone union with minimal adverse effects and excellent long-term outcome in 4 dogs. CLINICAL RELEVANCE: Direct intraoperative administration or fluoroscopically guided, minimally invasive delivery of rhBMP-2 may be an effective treatment modality for bone delayed- or nonunions and could potentially be used to stimulate new bone production in a variety of orthopedic surgical conditions in dogs.     

Comparison of two doses of recombinant human bone morphogenetic protein in absorbable collagen sponges for bone healing in dogs

OBJECTIVE: To determine the effects of 2 doses of recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge (rhBMP-2/ACS) on bone healing in dogs. ANIMALS: 27 adult dogs. PROCEDURES: Dogs underwent a mid-diaphyseal (1-mm) tibial osteotomy (stabilized with external skeletal fixation) and received an ACS containing 0.28 mg (0.2 mg/mL) or 0.56 mg (0.4 mg/mL) of rhBMP-2 or no treatment (control dogs). All dogs were examined daily; bone healing was assessed via radiography and subjective lameness evaluation every 2 weeks. After euthanasia at 8 weeks, tibiae were evaluated biomechanically and histologically. RESULTS: Control dogs required antimicrobial treatment for pin-site-related complications more frequently than did rhBMP-2/ACS-treated dogs. At 4 and 6 weeks, weight bearing was greater in dogs treated with rhBMP-2/ACS (0.2 mg/mL) than in control dogs, albeit not significantly. Compared with control treatment, both doses of rhBMP-2/ACS accelerated osteotomy healing at 4, 6, and 8 weeks, and the 0.2 mg/mL dose enhanced healing at 2 weeks; healing at 6 weeks was greater for the lower-dose treatment than for the higher-dose treatment. Histologically, healing at 8 weeks was significantly improved for both rhBMP-2/ACS treatments, compared with control treatment. Among groups, biomechanical variables did not differ, although less osteotomy-site failures occurred in rhBMP-2/ACS-treated groups. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs that underwent tibial osteotomy, rhBMP-2/ACS (0.2 mg/mL) appeared to accelerate bone healing and reduce lameness (compared with control treatment) and apparently augmented bone healing more than rhBMP-2/ACS (0.4 mg/mL). Compared with control dogs, rhBMP-2/ACS-treated dogs required antimicrobial treatments less frequently.     

Use of cancellous bone grafting to promote granulation tissue in a distal limb wound in a dog

A 5‐year‐old female spayed Shetland sheepdog presented for evaluation of bandage sores on the left pelvic limb after a splint was placed to stabilise a digit fracture incurred approximately 2 weeks previously. Multiple areas of necrosis were identified upon bandage removal. After debridement of devitalised tissue, a 4 cm wound on the plantar surface of the metatarsal bones (with exposed bone and tendons) remained. The Papineau technique (which involves removal of infected or necrotic tissue, placement of autogenous cancellous bone graft within a wound, and delayed skin closure) was used to treat this wound. Use of bone graft in this manner aims to promote early granulation tissue formation and reduce the time until wound reconstruction can be performed. Autogenous cancellous bone graft was harvested from the proximal humerus and placed within the metatarsal wound. Once a healthy granulation tissue bed was noted to cover the bone graft, a meshed full thickness skin graft was placed. To our knowledge, this is the first report of the Papineau technique being used for this purpose in a dog.     

Incorporation of Fresh and Cryopreserved Bone in Osteochondral Autografts in the Horse

The structural integrity of subchondral bone in fresh and frozen osteochondral autografts was investigated at month 3 in 10 horses. Two osteochondral autografts were harvested from the lateral aspect of the lateral trochlear ridge of the left talus in each of 10 anesthetized horses. Grafts were frozen in 7.5% DMSO. After 14 days, the thawed grafts were press-fitted into drill holes in the trochlear ridges of the right stifles. A fresh graft from the right hock was implanted in each left stifle. To control for the effects of surgery, a fresh graft was transferred from the right stifle to the left stifle. The end result was two grafts in each femoropatellar joint. Fresh and frozen bone grafts maintained a structurally intact support for the cartilage surface. Graft stability and surface congruency were determining factors in the outcome of the grafts. Incorporation of both types of graft was complete at month 3, but remodeling of the fresh grafts was more active.     

Recombinant human bone morphogenetic protein-2 in absorbable collagen sponge enhances bone healing of tibial osteotomies in dogs

OBJECTIVE: To compare the efficacy of 2 doses of recombinant human bone morphogenetic protein-2 (rhBMP-2) on tibial osteotomy healing in dogs. STUDY DESIGN: Experimental, randomized complete block (n=7). ANIMALS: Adult female dogs (n=21). METHODS: Right midshaft tibial osteotomies were created and stabilized with a 1-mm gap using type I external fixators. Seven dogs were untreated controls and 14 with osteotomies were treated with either 0.05 or 0.2 mg/mL rhBMP-2 delivered in an absorbable collagen sponge (ACS). At 8 weeks, dogs were euthanatized and bones were mechanically tested and examined by microscopy. RESULTS: Bone healing based on radiographic scoring, was significantly improved in dogs treated with 0.2 mg/mL of rhBMP-2 compared with the other groups; these tibiae were also significantly stronger and stiffer than 0.05 mg/mL rhBMP-2 and control osteotomized tibiae. Histologic scores were significantly better for 0.2 mg/mL rhBMP-2 group than 0.05 mg/mL rhBMP-2 group, but neither was significantly different from control. CONCLUSIONS: rhBMP-2 in ACS at a concentration of 0.2 mg/mL improves healing of tibial osteotomies in dogs compared with untreated controls and 0.05 mg/mL rhBMP-2 based on force plate analysis and radiographic evaluation. This was not confirmed histologically but treated bones had improved mechanical properties at 8 weeks. CLINICAL RELEVANCE: After a long bone fracture, dogs may face a long recovery period before full return of limb function. rhBMP-2, in association with good fracture fixation principles, may enhance bone healing in dogs with diaphyseal fractures.     

Mandibular condylectomy and meniscectomy for the treatment of septic temporomandibular joint arthritis in a horse

OBJECTIVE: To report use of mandibular condylectomy for treatment of advanced degenerative joint disease of the temporomandibular joint (TMJ) caused by sepsis. DESIGN: Clinical case report. ANIMALS: Two-year-old Noriker filly. METHODS: Computed tomography (CT) was used to confirm advanced degenerative joint disease of the left TMJ and for follow-up after mandibular condylectomy and removal of necrotic meniscus. RESULTS: Painful swelling (3 weeks duration) with drainage located just caudal to the left lateral canthus of the eye was associated with atrophy of the left masseter muscle, masticatory problems, and inappetence. There was incisor malocclusion with a 1.4 cm resting lateral mandibular deviation to the right and inability to open the mouth more than a few centimeters. Left mandibular condylectomy combined with meniscectomy and thorough debridement of the septic left TMJ resulted in resolution of clinical signs and complete return of function. Streptococcus zooepidemicus, intermediately resistant to penicillin and subsequently to enrofloxacin, was isolated from the wound. Regeneration of a mandibular "pseudocondyle" was evident on CT at 4 months. At 4 months and 1 year the filly had maximal mouth opening >10 cm and no malocclusion. CONCLUSION: Mandibular condylectomy can be used to facilitate management of septic TMJ arthritis. There was no radiologic or clinical evidence of TMJ ankylosis >1 year after meniscal removal. CLINICAL RELEVANCE: Mandibular condylectomy, including meniscectomy, is an acceptable treatment option for advanced TMJ septic arthritis and allowed return of normal masticatory function.     

Extensive bilateral odontogenic cysts in the mandible of a dog

A 5-year-old female neutered Boxer dog was diagnosed with extensive odontogenic cysts that affected the left and right mandibles. Rostral mandibular swelling was detectable clinically, and bilateral cystic mandibular lesions were identified radiographically. The dog's owners elected for euthanasia. A full postmortem was performed. Cystic cavities were confirmed in the body of each mandible, extending from the incisor teeth to the mid premolar region. Incisor, canine, and premolar tooth roots indented each cavity. Histologic examination of the cystic cavities reflected an inner lining of attenuated stratified squamous epithelium overlying a fibrous layer infiltrated by a mixed, predominantly mononuclear, inflammatory infiltrate.     

Transplantation of the Canine Distal Ulna as a Free Vascularized Bone Graft

An autogenous free vascular bone graft of the canine distal ulna was evaluated. The vascularity of the graft was based on a musculoperiosteal sheath supplied solely by the caudal interosseous artery and vein. Four autogenous heterotopic (ulna to tibia) vascular transfers were performed. Two avascular transfers were performed to provide baseline criteria from which the success of vascularized transfers could be assessed. Clinical lameness evaluation, serial radiographs, bone scintigraphy, and sequential fluorochrome bone labeling were performed after surgery in both vascular and avascular transfers. All dogs were free of lameness in the donor limb by the 26th postoperative day. Serial radiographs revealed rapid graft incorporation and hypertrophy in all vascularized grafts and severe bone resorption in nonvascularized grafts. Histology, microangiography, and evaluation of fluorochrome bone labels were performed 90 days after surgery to determine graft viability, incorporation and temporal remodeling patterns. Microangiography and fluorochrome assessment complemented the histological findings. Based on these findings the distal ulnar bone graft was determined to be both viable and structurally adequate for selected cases of long bone reconstruction.     

Congenital Glossocheilognathoschisis and Persistent Frenula Linguae in a Foal: A Case Report

This paper describes clinical findings and surgical treatment of a foal with multiple craniofacial defects (glossocheilognathoschisis; congenital midline cleft of the lower lip, mandible and tongue combined with bilateral persistent frenula linguae) admitted to the Surgery Clinics of Faculty of Veterinary Medicine, University of Kafkas, Turkey. A thorough clinical examination revealed cleft of the lower lip and mandible combined with glossoschisis (glossocheilognathoschisis) and bilateral extensive and restrictive membranous band (frenula) of tissue at the base of the tongue. Physical examination and radiography of the other organs and tissues of the foal were within normal limits. After sedation and general anesthesia, the persistent frenulas on the right and left parts of the tongue were transected, starting from normal tongue tissue, with the scissors. The tongue was completely freed after the transection of the remaining part of the frenulum, where right and left frenulas united, and the accompanying mucosal tissue on the mandibular symphysis was removed and underlying bone tissue was superficially curetted. Cerclage wire was placed under the mucosa of the mandible and was then passed among two drilled holes below the two incisors. These two pieces of wire were twisted together and anchored over the labial surface of the mandibular symphysis junction. The mandibular symphysis was then stabilized after cerclage wire tensing. A nasogastric tube was placed to permit enteral feeding. The foal was discharged 5 days after surgery. Telephone follow-up revealed that the foal had died 15 days after the surgical intervention.     

Histomorphometric comparison of measurements of trabecular bone remodeling in iliac crest biopsy sites and lumbar vertebrae in cats

Trabecular bone remodeling values of the right and left iliac crest and lumbar vertebrae in cats were quantitated histomorphometrically and were compared. Healthy cats were given calcein (n = 2) or oxytetracycline (n = 2) twice for double-labeling of bone. Static and dynamic variables of bone resorption and formation were determined. Bone remodeling variables between right and left iliac crest were not significantly different (P less than 0.05). Significant differences (P less than or equal to 0.05) were not detected between values of iliac crest and lumbar vertebrae except in the percentage of osteoid surface. Percentage of osteoid surface was significantly (P less than or equal to 0.05) increased in the iliac crest compared with that in the vertebral body. Although not significantly different, values for bone formation were generally greater in the iliac crest than in the vertebral body. In healthy cats, values of trabecular bone remodeling were comparable between right and left iliac crest, and also were comparable between iliac crests and lumbar vertebrae.     

Evaluation of the proximal portion of the femur as an autogenous cancellous bone donor site in dogs.

The proximal portion of the femur was evaluated as a source of autogenous cancellous bone in dogs. Bilateral oval cortical defects were created in the lateral subtrochanteric area of the femur in 16 dogs. Cancellous bone was removed and the weight recorded. Cancellous bone was similarly harvested from the proximal portion of the humerus in 7 of these dogs. Subtrochanteric femoral defects in 11 dogs were randomly assigned to receive cancellous bone graft obtained from the femur (n = 4) or the humerus (n = 7). Subtrochanteric defects in 5 dogs were not grafted. Radiographic assessment of subtrochanteric defects was performed at 4-week intervals, and histologic assessment at 4, 8, 16, and 24 weeks after surgery. Nongrafted donor sites healed by ingrowth of trabecular bone during the first 12 weeks after surgery. By week 24, the lateral cortical wall had reformed, but remodeling was incomplete. Donor sites grafted with cancellous bone healed similarly, but with more rapid healing and more complete remodeling evident by week 24. Although the mean weight of cancellous bone harvested from the proximal portion of the femur (0.82 +/- 0.22 g) was significantly (P less than 0.05) less than that harvested from the proximal portion of the humerus (1.38 +/- 0.29 g), there was no qualitative histologic or radiographic difference in bony healing of grafted defects. We determined that the proximal portion of the femur can be safely used to provide moderate amounts of cancellous bone, and that a second bone graft can be collected from the same subtrochanteric donor site after 12 weeks.     

In vivo osteoinductivity of gelatin β-tri-calcium phosphate sponge and bone morphogenetic protein-2 on an equine third metacarpal bone defect

This study evaluated the therapeutic effects of a gelatin-β-TCP sponge (sponge) incorporating BMP-2 (BMP-2/sponge) on bone regeneration in equines. Six bone defects were created in third metacarpals of five thoroughbred horses, and a total of six treatments were applied in a randomized manner. The treatments were BMP-2/sponge, BMP-2/gelatin hydrogel sheet (sheet), free BMP-2, bFGF/sheet, plain sponge, and plain sheet. The defects were monitored for 16 weeks by radiography and then examined by histological analysis. Radiographic evaluation scores of bone regeneration revealed significantly greater bone regeneration of defects treated with BMP-2/sponge than defects treated with plain sponge or BMP-2 sheet (P<0.05). In histological analysis, compact bone was observed over a wide area in the BMP-2/sponge treatment. We concluded that the treatment with BMP-2/sponge accelerated bone regeneration in the equines of this study.