Incorporation of an Allogenic Cortical Bone Graft Following Arthrodesis of the First Metatarsophalangeal Joint in a Patient with Hallux Rigidus

Hallux rigidus is degenerative arthritis of the first metatarsophalangeal joint characterized by pain and stiffness in the joint with limitation of motion and functional impairment. Recently, bone grafts have been introduced in orthopedic procedures, namely osteosynthesis and arthrodesis. Allografts can induce bone formation, provide support for vascular and bone ingrowth and have a low risk of immunological rejection. A 52-year-old female patient with hallux rigidus underwent arthrodesis of the first metatarsophalangeal joint using Shark Screw® made of allogenic cortical bone. Corrective surgery was performed after 10 weeks, and a 5 × 3 mm large part of the Shark Screw® with the surrounding patient’s bone was removed. A histological evaluation revealed a vascularized graft with the newly formed compact lamellar bone fitting exactly to the cortical graft. The bone surface was lined by plump osteoblasts with osteoid production, and osteocytes were present in the lacunae. The arthrodesis of the first metatarsophalangeal joint using an allogenic cortical bone graft results in fast, primary bone healing without immunological rejection. This case suggests that the cortical allograft is a good and safe treatment option with an excellent graft incorporation into the host bone. However, as the literature evaluating the histology of different bone grafts is scarce, further high-level evidence studies with adequate sample sizes are needed to confirm our findings.

Treatment of Pelvic Stenosis with Heterologous Graft and Subtotal Colectomy in a Cat

Background: The management of malunion of pelvic fracture and its complications may require from conservative to surgical methods, depending on the severity and temporal evolution. Thus, the aim of this present report is to describe the treatments adopted in a cat with severe pelvic stenosis.Case: An approximately 3-year-old neutered male crossbreed cat, weighing 3 kg, was presented due to difficulty in defecation in the previous eight months. According to its tutor, the cat was adopted one year earlier, with a history of pelvic fracture due to a run over, which had been treated conservatively. The tutor also mentioned that since the appearance of dyschezia, the cat had only been treated with enemas, but without success. In abdominal palpation, there was presence of pain and a mass of firm content in descending colon topography. The radiographic examination of the pelvis presented an exuberant bone callus, characterizing an old fracture, a consolidation with change of bone axis in the right ischium, together with megacolon and fecaloma. It was initially decided that a liquid glycerin-based enema would be performed, in conjunction with clinical treatment with administration of cisapride, dimethicone and lactulose. Although the medical treatment initially helped improve the clinical picture, the cat presented fecaloma two months later. Surgical treatment was then performed, in which distraction of the pubic symphysis with use of a heterologous cortical bone graft (canine tibia stored in glycerin 98%) was performed, as the tutor was not favorable to colectomy as the first option. However, after one month of intervention, despite good evolution, the animal again showed signs of dyschezia. At this point the tutor agreed to colectomy, which was subtotal with preservation of the ileocolic valve.Discussion: The initial treatment of the cat in this report, with administration of prokinetic, antifoaming agent and laxative was insufficient, as the cat again developed fecaloma after two months of use of such medications. In general, cats presenting dyschezia, with constipation and megacolon over a period of more than 6 months, may present irreversible lesion due to damage to the smooth muscle of the colon, with presence of hypertrophy and neuromuscular degeneration of the organ. The problem had already been explained to the tutor, who preferred the medical treatment, as until then the cat had only been treated with enemas. Several techniques have been used to promote the widening of the pelvic canal, including the pelvic symphysiotomy and use of spacers. Although the autograft stimulates osteogenesis more rapidly, there is difficulty in obtaining bones of adequate size and strength, one of the reasons why the heterologous bone was used in the present case. Even with adequate widening of the pelvic canal, the lesion’s evolution over time may have predisposed to irreversible damage of the colon in this case. Among existing techniques for resolution of megacolon in cats, coloplasty, partial colectomy, and subtotal colectomy can be cited. The latter technique was undertaken in the present case, in conjunction with ileocolic junction preservation, which has the advantage of a lower incidence of diarrhea. Thus, thesigns of dyschezia had ceased. In conclusion, the combination of procedures adopted for distraction of the pelvic symphysis and subsequent subtotal colectomy allowed adequate recovery of the animal without relapses during a follow-up period of five years. The use of the heterologous graft (canine tibia) for distraction of the pelvic symphysis behaved as a spacer of adequate size and resistance.

Using allogeneic cortical graft preserved in glycerin as spacer in the advancement of tibial tuberosity in 34 dogs

ABSTRACT: Cranial cruciate ligament is the main responsible for knee stability by preventing cranial tibial displacement regarding the femur. Deficiency in this ligament (CCLD) may cause subluxation of the tibia and dysfunction of the pelvic member due to overloading. Tibial osteotomies are among the more current surgical techniques for treating CCLD in dogs and they proportionate the dynamic stability by means of modifying bone geometry and the distribution of forces acting on the articulation. The objective of this work is to describe the use of the allogeneic cortical bone graft conserved in glycerin as a spacer on the tibial tuberosity advancement (TTA) for treating the CCLD. In order to do that, 34 dogs submitted to TTA surgery correction were evaluated, being 23 males (67.35%) and 11 females (32.35%). Surgical procedures happened from May 2011 to October 2015. Regarding the surgical procedure after osteotomy of the tibial tuberosity, a disk of allogeneic cortical disk, sawn wedge-hapsed, conserved in glycerin, proportions of 2x1mm was applied as spacer, enabling TTA. Advancements from 3 to 12 mm were executed, depending on the need of the patient. For animals with patella dislocation, trochleoplasty and TTA were executed in order to correct the deviation. The mean ± SD age of animals was 6.67±3.58 and weight was 15.16±12.97 kg. Mongrel dogs, Poodles and Yorkshire terriers were the most affected ones. From the 36 evaluated knees, 11 (30.56%) were associated with some traumatic process and in 25 (69.44%) there was no relation with previous trauma. From those wounds, 20 (55.56%) happened in the right limb and 16 (44.44%) in the left limb and two animals had CCLD bilaterally. Animals had continuous support, discreet drawer movement and negative tibial compression 15 days after surgery. At 30 days, 26 cases (72.22%) had firm support (FS); at 45 days, 24 cases (66 test at 7 and 67%) had FS and eight cases (22.22%) without claudication (WC). During subsequent radiographic evaluations the progressive incorporation of the graft and osteotomy union were observed. In this study, most of the diagnosed CCLD occurred in males diverging from results obtained by other authors that found greater frequency in females. Support without claudication it was observed in most of the cases of implants at 60 days. We concluded that the conserved allogeneic cortical bone graft was able to promote bone union in TTA of dogs with CCLD. None of the animals had signs of contamination, infection of the surgical wound or rejection related with the presence of the graft, demonstrated by the complete graft-bone incorporation observed early at 45 days in some animals. The glycerin was a good conservation medium for those fragments intended for grafting because, besides being of low cost, it kept bone fragments free of contamination, reducing antigenicity and preserving the functions of osteoinduction and osteoconduction. The possibility of molding the graft to the animal need is a characteristic favorable to executing the modified technique that could be molded according to the size of the animal, allowing perfect adaptation to the osteotomized local in different breeds. Intercurrences commonly observed in TTA with patellar dislocation, meniscal lesions, tibial crest fracture and displacement were not found in the animals of this study, probably due to the better distribution of forces between the pass screw in TT and the TTA plate confirming that it has good adaptation to the technique conferring to the modified TTA advantages regarding the conventional TTA.

Comparison of lyophilization, and freezing in honey as techniques to preserve cortical bone allografts used to repair experimental femoral defects in domestic adult cats

Cats with orthopedic conditions are a prominent part of the clinical work of veterinary. Conditions such as comminuted fractures, bone tumors and non-unions are often difficult to repair and may require the use of bone grafts for treatment. This study evaluated cortical bone allografts preserved in honey, frozen or lyophilized for correcting long bone defects created in the diaphysis of the right femur of domestic cats (n=24). In the control group (n=6), the defect was repaired using autogenous cortical bone graft. In the remaining animals (n=6/group), the defect was repaired with cortical bone allografts preserved in honey, frozen or lyophilized. Success of graft incorporation and length of time for consolidation were assessed through clinical, radiographic and histological evaluations performed up to 180 days. In the control, frozen, honey and lyophylized groups, respectively, success of graft incorporation was 91.6%, 83.3%, 75%, and 25%, with corresponding mean length of time for consolidation of 83.1, 78, 105 and 120 days. Incorporation percentage in the lyophilized group was significantly lower than in the frozen and control groups. In conclusion, bone grafts preserved in honey or frozen were effective for repairing cortical defects in the femurs of cats as compared to autogenous cortical bone grafts.