Copper Bead Therapy in Severe Bone Infection: A Rabbit Tibial Model.

OBJECTIVE: We investigated the benefits of a local preventive therapy based on copper beads against severe bone infection using a rabbit open tibial fracture model. MATERIALS AND METHODS: Cotton mesh balls soaked in a very high concentration of Staphylococcus aureus ATCC 6538 culture were inoculated in drilled holes of the tibiae of treated and control groups. The treated group was also implanted with small copper beads simultaneously, as prevention therapy. RESULTS: Survival rate in the treated group was 67% compared with 25% in the control group (difference 40%, for a 95% confidence interval: 40%, 93.4%). The few remaining animals in the control group had bone lesions which developed into osteomyelitis, while the tibiae of treated group had clear signs of reparatory processes. Sixty days after inoculation, signs of local-only toxicity were observed in healthy tibia of a separate non-infected control group. Drawbacks of copper toxicity were weighed against the threat of septicaemia and also against prolonged use of powerful systemic antibiotic medications in severe bone contamination. CINICAL SIGNIFICANCE: It was found that the proposed therapy prevented septicaemia and the spread of infection, and it also induced reparatory processes. The findings of this study may be relevant in antisepsis of open fractures in less appropriate medical settings (such as military camps or remote locations), as well as in severe bone infections.

Axial sesamoiditis in the horse: A review.

Axial sesamoiditis or osteitis of the proximal sesamoid bones (PSBs) in the horse is described as a rare condition. The cause remains unknown and speculative, with vascular, infectious, and traumatic aetiologies implicated. It is specifically associated with injury of the palmar or plantar ligament (PL), also known as the intersesamoidean ligament. Imaging findings are generally rewarding and radiological changes are typical, if not pathognomonic, for the condition. Lesions consist of bone lysis at the apical to mid-body axial margins of the PSBs, with variable degrees of joint effusion. Radiographic technique warrants careful attention to make a diagnosis, and exposure factors may need to be adjusted. Perineural, intra-articular and intra-thecal anaesthesia does not seem to provide consistent improvement of lameness in these cases, with literature reporting inconsistent findings. Ultrasonographic findings include digital flexor sheath effusion, loss of the normal fibre structure of the PL at its attachment to the PSBs, abnormal echogenicity or change in thickness of the PL, and irregular hyperechoic cortical margins of the axial margins of the PSBs. Scintigraphy, computed tomography and magnetic resonance imaging, although not necessary to make a diagnosis, may add valuable information regarding the location and extent of lesions. The prognosis remains guarded to poor for return to athletic function. The focus of this paper is a comprehensive review of the proposed aetiopathogenesis of the condition, the prognosis, and a summary of the literature findings with focus on the notable diagnostic imaging features, including radiography, ultrasonography, scintigraphy, computed tomography and magnetic resonance imaging.

SUCCESSFUL TREATMENT OF DIGITAL OSTEITIS BY INTRAVENOUS REGIONAL PERFUSION OF CEFTIOFUR IN AN AFRICAN ELEPHANT (LOXODONTA AFRICANA).

A 41-yr-old African elephant ( Loxodonta africana ) presented with a swollen third digit of the left forelimb and a 2-cm hole in the pad. Corrective trimming, topical treatments, and an oral antibiotic resulted in apparent resolution; however, it reoccurred after 4 mo. Radiographs suggested bone lysis in the third phalanx, with the primary differential diagnosis being septic osteitis. Flushing with metronidazole solution and intravenous regional perfusion (IVRP) of the foot were commenced. A tourniquet was applied just above the carpus, an interdigital vein was identified by ultrasound, and into this vein 2 g (20 ml) of ceftiofur sodium solution, followed by 60 ml of heparinized saline, was administered. The foot was kept raised for 25 min and then the tourniquet was removed. IVRP was repeated every other day for 70 treatments over 6 mo. Healing occurred, which was confirmed radiographically. IVRP offers an excellent treatment modality in a well-trained elephant.

[Leishmania infantum induced bone lesions in a dog]. / Leishmania-infantum-bedingte Knochenläsionen bei einem Hund.

A 3-year-old Labrador Retriever originating from Spain was presented with a left-sided hind limb lameness for several months. The orthopedic examination revealed a pain response when palpating the left tarsal joint. Radiographic and computed tomographic studies showed polyostotic, aggressive osteolytic bone lesions with mild erosive arthritis. The diagnosis of canine leishmaniasis was confirmed by bone biopsy and the detection of the pathogen by PCR. Three weeks after initiation of therapy with allopurinol, the dog presented no signs of lameness. Eight months after start of therapy, radiographic examination revealed moderate regression of the osteolytic bone lesions.

Concurrent infection with Cryptococcus neoformans/gattii species complex and Mycobacterium avium affecting the subcutis and bone of a pelvic limb in a cat.

This paper describes a cat with severe localised infections with Cryptococcus neoformans/gattii species complex and Mycobacterium avium affecting the subcutis and underlying fascia and bone of the right pelvic limb. The simultaneous isolation of both pathogens in this patient was unexpected and posed unique issues concerning both diagnosis and clinical management. The aetiopathogenesis of this infection is discussed in relation to aspects of diagnosis and therapy.

Systemic Conidiobolus incongruus infection and hypertrophic osteopathy in a white-tailed deer (Odocoileus virginianus).

Postmortem examination of a free-range white-tailed deer (Odocoileus virginianus) revealed severe emaciation, bilateral firm proliferation of the metatarsal diaphyses, and a large intrathoracic mass associated with the accessory lung lobe. Smaller masses were evident in the abomasum, duodenum, omentum, and the capsular surface of the liver. Microscopically, the masses were similar and were diagnosed as eosinophilic granulomas with intralesional fungal hyphae characteristic of Zygomycetes spp. Fungal hyphae were identified as Conidiobolus incongruus by 18S ribosomal RNA sequencing on fresh lung tissue. Furthermore, the proliferative lesions of the metatarsal bones along with the intrathoracic mass were compatible with hypertrophic osteopathy.

[The former knackers yard in Zurich-Albisrieden: pathological findings in excavated animal bones]. / Wasenplatz am Letzigraben in Zürich-Albisrieden: pathologische Befunde am Tierknochenfundgut.

During archaeological excavations in the former knackers yard in Zurich-Albisrieden bones and joints of 8 horses and 1 mule were found and examinedfor pathological lesions. Degenerative changes (arthropathies, spondylosis and spondylarthrosis) as well as tooth irregularities were most often seen. One horse had a discospondylitis and spondylitis of C7 and Th1.

Spinal arthropathy associated with Ochrobactrum anthropi in free-ranging cane toads (Chaunus [Bufo] marinus) in Australia.

Inflammatory or degenerative pathology involving the vertebral bodies and/or ventral intervertebral joints has been described in numerous species, both captive and free ranging, including mammals, birds, and snakes, although never in amphibians. We described 15 cases of a newly recognized spinal arthropathy in adult cane toads (Chaunus [Bufo] marinus), an invasive species in Australia. Grossly appreciable lesions consisted primarily of ventral proliferation of bone and cartilage that resulted in ankylosis. Histologic examination of the entire vertebral columns of the 15 affected toads revealed 13 toads to have lesions at multiple intervertebral sites, totalling 41 intervertebral joints with lesions. Most lesions involved bone and cartilage proliferation that resulted in fusion of the joint, with (n = 15) or without (n = 9) associated pyogranulomatous inflammation. In the remaining 17 affected joints, histologic lesions were characterized by degeneration of articular cartilage without joint fusion. In addition, in one of these joints, there was also hemorrhage and pyogranulomatous inflammation. Bacterial culture of affected joints in 9 toads and grossly normal joints in 4 control toads resulted in isolation of Ochrobactrum anthropi in 7 affected toads but in none of the controls (P < .01). We proposed an interaction between degenerative and bacterial etiologies in the pathogenesis of this condition. Invasive toads may be predisposed to this condition because of their large size; increased rates of movement; and, possibly, immunosuppression resulting from inhabiting a novel environment.

Hypertrophic osteopathy associated with pulmonary Eikenella corrodens infection in a dog.

CASE DESCRIPTION: A 4-year-old English Pointer was examined because of chronic, progressive signs of pulmonary disease and failure to respond to medical treatment. CLINICAL FINDINGS: At examination, radiography of the thorax revealed increased pulmonary opacity and air bronchograms in the right caudal lung lobe, and radiography of the forelimbs revealed periosteal bone production typical of hypertrophic osteopathy. Attempts to isolate a causative organism included bacterial culture of bronchoalveolar lavage fluid and a lung tissue specimen obtained via fine-needle aspiration. Despite a cytologic diagnosis of septic suppurative inflammation in the lavage fluid, those specimens did not yield bacterial growth. However, a biopsy specimen obtained during a lung lobectomy procedure yielded growth of Eikenella corrodens. TREATMENT AND OUTCOME: Despite successful surgical removal of the consolidated lung lobe and initiation of antimicrobial treatment, the dog died 6 days after surgery. CLINICAL RELEVANCE: The authors are not aware of reports of pulmonary infection with E. corrodens in animals. Infection with the organism is rare, but it is possible that infections are underreported given that the organism is difficult to culture and biopsy may be necessary to obtain enough tissue to yield a diagnosis.

Elution of metronidazole and gentamicin from polymethylmethacrylate beads.

OBJECTIVE: To characterize the elution and bioactivity of metronidazole and gentamicin sulfate polymerized, individually and in combination, with polymethylmethacrylate (PMMA). STUDY DESIGN: In vitro experimental study. METHODS: PMMA beads containing metronidazole (3 concentrations), gentamicin sulfate, or metronidazole and gentamicin sulfate were immersed in 5 mL of phosphate-buffered saline in triplicate. Eluent was replaced at specified time intervals for 1 or 21 days, and antibiotic concentrations were measured by high-performance liquid chromatography. Changes in antibiotic bioactivity attributable to polymerization or copolymerization of the antibiotics with PMMA, ethylene oxide sterilization, and storage of AIPMMA beads containing metronidazole were evaluated. RESULTS: Antibiotic elution patterns were similar for all groups. Day 1 elution for groups containing metronidazole or gentamicin individually represented a mean 63%-66% and 79%, respectively, of the 21-day total. Approximately 50% of the day 1 elution occurred during the first hour. The elution of metronidazole was dose dependent. The elution of metronidazole (day 3-21) and gentamicin (all days) was significantly greater when metronidazole and gentamicin were combined (P <.05). The addition of metronidazole delayed polymerization of PMMA. Neither polymerization nor copolymerization of metronidazole and gentamicin with PMMA, gas sterilization, or 2-month storage of beads containing metronidazole significantly affected antimicrobial bioactivity. CONCLUSIONS: Metronidazole elution from PMMA was dose dependent. Copolymerization of metronidazole and gentamicin sulfate in PMMA resulted in increased rates of elution. Intraoperative preparation of metronidazole-impregnated PMMA beads is not practical, but sterilization and storage for 2 months should not affect efficacy. CLINICAL RELEVANCE: The local delivery of biologically active metronidazole and gentamicin by elution from PMMA is feasible.

In vitro elution of gentamicin, amikacin, and ceftiofur from polymethylmethacrylate and hydroxyapatite cement.

OBJECTIVE: To compare the elution characteristics of ceftiofur and liquid and powdered gentamicin and amikacin from polymethylmethacrylate (PMMA) and from hydroxyapatite cement (HAC). METHODS: PMMA and HAC beads in triplicate were impregnated with various amounts and formulations of antibiotics. Beads were immersed in 5 mL of phosphate buffered saline that was replaced at 1, 3, 6, and 12 hours, and 1, 2, 3, 5, 7, 10, 14, 18, 22, 26, and 30 days. The eluent was stored at -70 degrees C until assayed within 2 weeks by microbiological assay (gentamicin and amikacin) or capillary electrophoresis (ceftiofur). RESULTS: Rate of elution for all beads was greatest within the first 24 hours. Cumulative release of total antibiotic dose from beads over 30 days was significantly greater from HAC than PMMA. Antibiotic elution was directly related to the amount of antibiotic incorporated into the cement. Powdered and liquid forms of gentamicin had similar elution rates from PMMA. Elution of amikacin from PMMA beads was greater when the powdered form was used compared with liquid amikacin. Eluent concentrations of ceftiofur were similar to those of the aminoglycosides during the first 3 to 7 days but then decreased precipitously by comparison. CONCLUSIONS: Elution of antibiotics from HAC was greater than from PMMA. Gentamicin- and amikacin-impregnated PMMA and HAC released bactericidal concentrations of antibiotic for at least 30 days. Ceftiofur-impregnated PMMA or HAC is unlikely to provide long-term bactericidal concentrations. CLINICAL RELEVANCE: Gentamicin and amikacin elute effectively from PMMA and HAC.

Scintigraphic detection of equine orthopedic infection using Tc-HMPAO labeled leukocytes in 14 horses.

The aim of this study was to evaluate the diagnostic value of 99mTc-HMPAO leukocyte scintigraphy (LS) by means of a retrospective review of its use in 14 horses that were evaluated for orthopedic infection as a cause of lameness. A total of 17 LS exams were performed in 14 horses. LS studies were positive in 10 of 14 horses. A bacterial infection was confirmed with cytology or culture in 9 of 10 positive horses. Negative LS studies occurred in 4 of 14 horses. Necropsy confirmed the lack of infection in 2 of the 4 horses. Other clinical data and a favorable clinical outcome supported a negative study in the other 2 horses. No false negative or false positive studies were identified. It may be concluded that HMPAO-LS is an effective tool for the diagnosis of orthopedic infection in horses.

Gas. Radiographic indicator of infection.

Gas is probably the best single radiographic indicator of infection in cattle, especially in and around the digits. With high quality images and a high-intensity light, gas may be detected in small pockets within the soft tissues, effacing bone surfaces, or within joints. This article illustrates the varied radiographic appearances of gas associated with infection, and the radiographic projections that optimize its detection.

Study of leg weakness in two commercial broiler flocks.

The major causes of leg weakness/lameness were investigated in two male commercial broiler flocks. The numbers of dead and lame birds culled from the flocks each day were recorded by the flock managers. Forty-four lame birds and 22 sound birds were examined postmortem during a period of six weeks and the proximal and distal end of each femur, tibiotarsus and tarsometatarsus were examined histologically. Attempts were made to isolate bacteria and viruses from the proximal end of each femur. Blood samples were examined for antibodies to chicken anaemia virus (CAV), infectious bursal disease virus (IBDV) and Mycoplasma species. Bacterial chondronecrosis with osteomyelitis was identified in the proximal end of the femur of eight of the 44 lame birds, and in the proximal end of the tibiotarsus of a further bird (20.4 per cent). Gram-positive bacteria were present in all the lesions. Staphylococcus aureus was recovered from 62.5 per cent of the lesions confirmed by histology. Bacterial chondronecrosis associated with S aureus has thus been identified as an important cause of leg weakness in these commercial broilers. Lesions suggestive of the condition were visible macroscopically in only 11.1 per cent of the cases subsequently diagnosed by histology and bone histology is therefore required before a diagnosis can be excluded. Angular limb deformities (13.6 per cent) and spondylolisthesis (11.4 per cent) were the most common macroscopic lesions identified as causes of lameness. The overall incidence of tibial dyschondroplasia was similar in both the lame and sound broilers, but severe lesions were found only in lame birds (4.5 per cent).