Premature closure of the proximal physis of the humerus in a dog as a result of harvesting a cancellous bone graft

A 5-month-old castrated male mixed-breed dog was evaluated because of lameness of the right forelimb. Physical examination revealed pain on manipulation of the right elbow joint, and radiography revealed premature closure of the distal physis of the radius with subluxation of the right elbow joint. Corrective osteotomy of the radius was performed to increase the length of the radius and establish congruity of the elbow joint. Cancellous bone was obtained from the proximal portion of the humerus and used as a graft at the osteotomy site. The dog did well after surgery. Four months after surgery, the dog again was lame on the right forelimb. Physical examination revealed instability of the right shoulder, and manipulation of that area elicited signs of pain. Radiography revealed caudomedial subluxation of the right shoulder as well as deformity of the humeral head and hypoplasia of the greater tubercle. It was presumed that these changes were associated with collection of the cancellous bone graft during the initial surgery, which resulted in premature closure of the proximal physis of the humerus. To our knowledge, this is the first report of premature closure of the proximal physis of the humerus as a result of procurement of a bone graft.     

Fracture of the humerus after cancellous hone graft harvesting in a dog

A five-year-old male Shetland sheepdog underwent calcaneoquartal arthrodesis for instability of the proximal intertarsal joint. A cancellous bone graft was harvested from the proximal humerus and packed around the arthrodesis site. Twenty-four hours postoperatively the dog developed a non-weightbearing forelimb lameness. Clinical and radiographic examination revealed a fracture of the humerus through the hole used to obtain the graft. Surgical repair of the fracture led to an uneventful recovery.     

Lag screw and cancellous bone graft fixation of transverse proximal sesamoid bone fractures in horses: 25 cases (1983-1989).

Case records of 25 horses with transverse fractures of the proximal sesamoid bone were reviewed to evaluate the success of treatment. All fractures were repaired by use of lag screw fixation and an autogenous cancellous bone graft because the fracture fragments were considered too large for surgical removal and reconstruction of the suspensory apparatus was necessary. Radiography was performed in all cases, and the fractures were classified into 3 types: (1) proximal midbody fractures, which included all fractures in the proximal aspect of the sesamoid bone that resulted in fragments involving greater than one third but less than one half of the total mass of the sesamoid bone; (2) midbody fractures that divided the bone into 2 equal portions; and (3) distal midbody fractures, which included transverse fractures in the distal aspect of the sesamoid bone that resulted in fragments involving greater than one third but less than one half of the total mass of the sesamoid bone. Of these cases, race records were obtained for 9 Standardbreds and 5 Thoroughbreds. Postoperative performance criteria evaluated were the ability to train and start 1 race, ability to maintain preinjury class of racing, earnings per start, and the number of starts following surgery. In Thoroughbreds, fractures occurred most commonly in the right forelimb; in Standardbreds, the left hind limb was most commonly involved. The midbody fracture was the most common type in both breeds, and the distribution of fracture location within the sesamoid bone was similar for both breeds.(ABSTRACT TRUNCATED AT 250 WORDS)     

Use of cancellous bone graft in treatment of navicular bone osteomyelitis in a foal

A 3-month-old Quarter Horse filly stepped on a fence staple and developed navicular bone osteomyelitis of the right hindfoot. A 1.5-cm spherical portion of medullary cavity containing purulent material was debrided and flushed with 0.9% NaCl solution. Cancellous bone was collected from a caudal sternebra and placed into the defect. The solar defect had filled with granulation tissue and was epithelialized 6 weeks after surgery. At 6-month follow-up evaluation, the navicular bone defect had healed and the foal was sound on the limb. Cancellous bone grafting may have merit for the treatment of navicular bone osteomyelitis in the horse.     

Evaluation of a laparoscopic technique for collection of serial full-thickness small intestinal biopsy specimens in standing sedated horses

OBJECTIVE: To assess a technique for laparoscopic collection of serial full-thickness small intestinal biopsy specimens in horses. ANIMALS:13 healthy adult horses. PROCEDURES: In the ex vivo portion of the study, sections of duodenum and jejunum obtained from 6 horses immediately after euthanasia were divided into 3 segments. Each segment was randomly assigned to the control group, the double-layer hand-sewn closure group, or the endoscopic linear stapler (ELS) group. Bursting strength and bursting wall tension were measured and compared among groups; luminal diameter reduction at the biopsy site was compared between the biopsy groups. In the in vivo portion of the study, serial full-thickness small intestinal biopsy specimens were laparoscopically collected with an ELS from the descending duodenum and distal portion of the jejunum at monthly intervals in 7 sedated, standing horses. Biopsy specimens were evaluated for suitability for histologic examination. RESULTS: Mean bursting strength and bursting wall tension were significantly lower in the ELS group than in the hand-sewn and control groups in both the duodenal and jejunal segments. Use of the hand-sewn closure technique at the biopsy site reduced luminal diameter significantly more than use of the stapling technique. In the in vivo part of the study, all 52 biopsy specimens collected during 26 laparoscopic procedures were suitable for histologic examination and no clinically important perioperative complications developed. CONCLUSIONS AND CLINICAL RELEVANCE: Laparoscopic collection of serial full-thickness small intestinal biopsy specimens with a 45-mm ELS may be an effective and safe technique for use in healthy adult experimental horses.     

Comparison of bone healing by demineralized bone matrix and autogenous cancellous bone in horses

OBJECTIVE: The purpose of this study was to compare bone healing induced by equine demineralized bone matrix (DBM) to autogenous cancellous bone graft (ACB) or no graft (control) in a rib-defect model in horses. STUDY DESIGN: The osteogenic properties of ACB and DBM were evaluated in bilateral 19-mm circular defects created in the outer cortex of the 6th and 8th ribs of each horse. ANIMALS OR SAMPLE POPULATION: Eight mature horses. METHODS: Three rib defects in each horse were randomly treated with each of the 3 treatment groups, and the fourth rib defect received a random treatment. Rib sections, including the defects, were harvested 56 days after implantation and examined for bone mineral density, percent ash and calcium and graded for signs of radiographic and histological healing. RESULTS: All ribs were fractured at the defect site and were classified as nonunion fractures 56 days after implantation. There were no significant differences among groups in bone mineral density and signs of radiographic or histological healing. There was an increased volume of bone in control and ACB-treated sites compared with DBM-treated sites. Rib defects treated with ACB were significantly higher in percent ash and calcium than those treated with DBM. DBM elicited no inflammatory reaction, and remodeling occurred around the periphery and within vascular channels of the decalcified particles. CONCLUSION: DBM particles remodel from the periphery, which may explain the significantly lower percent ash, calcium, and bone when compared with ACB, because 2- to 4-microL pieces of DBM may act as space-occupying masses until completely mineralized. There was no evidence of enhanced healing associated with the use of DBM in this model. CLINICAL RELEVANCE: Particles of 2 to 4 mm DBM should not be used as an aid to fracture repair because particles of this size interfere with normal mineralization. However, our model of nonunion fracture healing may be useful in future studies.     

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.     

Chondrosarcoma of the proximal humerus in a cat

Chondrosarcoma of the proximal humerus was diagnosed in a four-year-old, castrated male, domestic shorthair cat that was presented with a slowly growing solid mass in the region of the proximal humerus. Forequarter amputation was advised, but declined by the owners. Following surgical debulking clinical signs resolved, but two months after surgery the cat was readmitted because the mass had recurred in the same region. The forequarter was amputated. Histopathological evaluation of the tumour confirmed the diagnosis of chondrosarcoma. Follow-up examinations performed over a period of 15 months from initial presentation revealed that the cat was doing well and had no signs of metastatic disease. To the authors' knowledge, this is the first reported case of chondrosarcoma of the proximal humerus in a cat to be diagnosed and surgically treated. This case demonstrates that animals with such tumours may recover well after complete excision.     

Osteosarcoma in the proximal humerus of a mare

A 15‐year‐old Quarter Horse mare was examined for significant and progressive lameness in the right front limb. On physical examination, muscle atrophy over the scapular and pectoral regions were noted. A pain response was elicited on palpation of the scapulohumeral joint. No other abnormalities were noted on examination of the limb. Diagnostic nerve blocks ruled out a source of lameness in the distal limb. Arthrocentesis of the scapulohumeral joint was performed and results were within normal limits. Radiographs of the right scapulohumeral joint revealed an extensive, aggressive bone lesion in the proximal humerus, suspected to be an osteosarcoma. After a course of nonsteroidal anti‐inflammatory therapy, minimal improvement to the lameness was noted. The owner elected to subject the horse to euthanasia due to the lack of significant response to treatment. Post mortem radiographic and histological examinations determined a definitive diagnosis of an osteosarcoma in the proximal humerus.     

Evaluation of a minimally invasive arthrodesis technique for the carpometacarpal joint in horses

Objective: To evaluate a minimally invasive technique for arthrodesis of the carpometacarpal (CMC) joint in horses. Study Design: Experimental study. Animals: Healthy horses (n=6). Methods: A 5.5 mm, 3‐drill tract arthrodesis technique was evaluated in 1 randomly selected CMC joint in each of 6 normal horses. Peak vertical ground reaction force (GRF) values were recorded before surgery and at 6, 8, and 12 months thereafter. Radiographic and clinical lameness scores were assigned at regular intervals until 12 months after surgery when the horses were euthanatized. Gross and histologic examinations were performed on the treated CMC joints. Results: After surgery, all horses were lame. Clinical resolution of lameness occurred in 2 by 12 months. Mean peak vertical GRF values significantly differed between treated and nontreated limbs at all recorded time points after surgery. Radiographic scores significantly differed from day 0 at all times after surgery, but did not change significantly after 4 months. Intraarticular bony ankylosis only occurred in 2 horses, based on gross, histologic, and microradiographic examination of sagittal sections of the operated CMC joints. Conclusion: The 5.5 mm, 3‐drill tract arthrodesis technique was considered successful in only 2 of 6 normal CMC joints treated. Greater articular damage may be necessary to achieve arthrodesis in normal horses. Better results may be achieved by technique modification or in horses affected by CMC osteoarthritis.     

Stabilization of a proximal femoral physeal fracture in a filly by use of cancellous bone screws.

A Salter-Harris type-II fracture of the proximal portion of the right femur in a 2-month-old filly was reduced and stabilized with three 6.5-mm-diameter, 100-mm-long cancellous bone screws through a dorsal approach to the right coxofemoral joint. The screws were removed after 11 months because the filly became lame in the affected limb. The surgical wounds dehisced despite preventive measures, most likely because of tightness of skin in the coxal region. Seven years after the original injury, the horse could perform vigorous paddock exercise without any disability. Early internal fixation of proximal femoral physeal fractures in foals can provide a good long-term prognosis.     

Assessment of a bone biopsy technique for measuring tiludronate in horses: a preliminary study

This study assessed the feasibility of measuring tiludronate in horses using a minimally invasive bone biopsy technique. Eight horses were treated with intravenous (IV) tiludronate [1 mg/kg bodyweight (BW)], either once (n = 4) or twice, 28 d apart (n = 4). The horses that were treated once were euthanized on days 1, 43, 57, or 92 and those that were treated twice, were euthanized on days 112, 154, 194, or 364. Bone samples were taken bilaterally from each horse at 4 sites: the third metacarpal bone (MCIII), the 13th rib (R13), the tuber coxae (TC), and the cuboid bone (CB). Test samples were taken with a 5-mm diameter dental drill, while larger reference samples were taken with an osteotome. The concentrations of tiludronate were measured by high performance liquid chromatography (HPLC) with ultraviolet (UV) detection. The TC was the easiest site to sample, and no technical difficulties were encountered for extraction and measurement. Drill sampling at the MCIII was difficult. Moreover, both the extraction and measurement caused technical problems and results were unreliable in most cases (93%). Drill samples obtained from the R13 were very small and access to the CB required considerable dissection, which would not be feasible in vivo. Forty-six percent and 36% of the tiludronate measurements performed on the R13 and CB samples, respectively, were unreliable. The ratio of tiludronate concentrations ranged from 73% to 185% (median: 118%) in the TC, 65% to 208% (median: 81%) in the R13, and 26% to 110% (median: 57%) in the CB. In all but 1 horse, the highest concentrations of tiludronate were found in the TC. It was concluded that bone biopsies performed at the TC were adequate for measuring tiludronate in horses and should be considered in future for repeated measurements over time in living animals.     

Tunnel grafting for wound repair in horses: a novel technique in graft production and placement

There are several skin grafting methods described in the human and animal literature. Currently, there are five types of free grafts used in horses: pinch and punch grafts, split and full-thickness sheet or mesh grafts and tunnel grafts. Published methods of tunnel grafting describe the use of alligator forceps. The alligator forceps create a poor tunnel and are excessively traumatic to the granulation bed. This technique utilised a 13G Jamshidi needle that was placed across the granulation bed and created a uniform tunnel. The Jamshidi needle was atraumatic to the granulation bed increasing the opportunity for graft survival. A twin bladed scalpel allowed for the quick creation of uniform width grafts. Removal of the overlying tunnel ‘roof’ took place 5–14 days later to allow graft expansion. This case series included five horses with distal limb wounds and one with a wither injury. Four horses required general anaesthesia for graft placement and three required general anaesthesia for the removal of the tunnel roof. The acceptance of the grafts varied from 70% to 100%. Graft expansion to cover the granulation tissue took 2–5 months. This case series demonstrates that this technique of graft production and placement is an easy method for achieving successful skin grafting. Compared to other graft types, tunnel grafts are more readily accepted. Cosmetic and functional results achieved are better than those with pinch and punch grafts. Tunnel grafting does not require expensive equipment or advanced training, and in some cases can be performed under standing sedation.     

Comparison of autogenous cancellous bone grafts obtained from the sternum and proximal portion of the tibia of llamas.

OBJECTIVE: To describe the anatomy of the sternum in llamas, define the surgical approach to the sternum for collection of cancellous bone graft tissue, and compare the histologic appearance of graft tissue obtained from the sternum with that obtained from the proximal portion of the tibia. DESIGN: Prospective study. ANIMALS: 12 llamas, 3 to 19 years old, that had been submitted for necropsy. PROCEDURE: Radiographs were taken of the sternum and left tibia of the llamas. Measurements of the sternum were determined from the radiographs and adjusted for magnification. Sternebrae volumes were estimated from these measurements. Anatomic dissections to the center of the fourth sternebra and the proximal portion of the tibia were made, and a surgical approach to the sternum was developed. Cancellous graft tissue was obtained from each site and submitted for histologic evaluation. RESULTS: Sternebrae 3, 4, and 5 were significantly larger in volume than the other sternebrae. The ventral aspect of the fourth sternebra was readily accessed for removal of graft tissue by making a 6-cm-long ventral midline incision centered 17 cm craniad to the xipnoid. Mean soft tissue thickness overlying the ventral aspect of the fourth sternebra was 3.1 cm. More tissue was obtained from the sternal (mean, 9.11 g) than from the tibial (mean, 5.16 g) sites. Sternal graft tissue consisted of trabecular bone spicules with predominantly hematopoietic marrow, whereas tibial tissue consisted of trabecular bone spicules with only fatty marrow. CONCLUSIONS AND CLINICAL RELEVANCE: The fourth sternebra in llamas is readily accessible for obtaining autogenous cancellous bone graft tissue that consists of predominantly hematopoietic marrow.     

Primary haemangiosarcoma in the proximal humerus of a Clydesdale gelding

An 11‐year‐old Clydesdale gelding was presented for investigation of left forelimb lameness of 2 weeks' duration. The use of scintigraphic imaging helped to localise the source of lameness to the left proximal humerus. In this report, the clinical and diagnostic imaging features of a primary osseous haemangiosarcoma in a horse are described, along with the challenges of establishing a definitive diagnosis ante mortem. In addition, neoplasia of the appendicular skeleton should be considered a differential cause of lameness in the horse.     

Use of autogenous cancellous bone graft for treatment of osteolytic defects in the phalanges of three cattle.

Osteolytic defects were detected radiographically in the distal sesamoid bone of a 16-month-old Bralers heifer, in the middle phalanx of a 14-month-old American Gray Brahman bull, and in the distal phalanx of a 3-year-old American Gray Brahman bull. The articular cartilage was damaged in each animal because of osteolysis or pathologic fracture. After each animal was anesthetized and positioned in lateral recumbency, the lesions were curetted and packed with cancellous bone harvested from the same animal's tuber coxae. Basic postoperative management involved stall rest and immobilization of the graft site with a fiberglass cast (42 to 79 days), after which a support bandage was used for approximately 2 weeks. Recurrence of lameness has not been observed in these animals for 60 months, 58 months, and 21 months, respectively. These cases exemplify the benefit of using an autogenous cancellous bone graft for treatment of severe osteolysis of a digit in cattle.