Unicortical condylar fracture of the Thoroughbred fetlock: 45 cases (2006-2013).

REASONS FOR PERFORMING STUDY: Fracture of the metacarpal/tarsal condyle is usually preceded by prodromal pathology. Early recognition of injury is desirable to minimise the risk of serious breakdown; however, the clinical and diagnostic characteristics of unicortical condylar fractures have been poorly documented to date. OBJECTIVES: To describe the clinical, imaging and outcome features of racehorses in first opinion practice diagnosed with short unicortical fracture of the metacarpal/tarsal condyle. STUDY DESIGN: Retrospective case series. METHODS: All flat racehorses sustaining a unicortical condylar fracture while under the primary care of a single first opinion UK veterinary practice (2006-2013) were identified from imaging records and histories analysed for clinical presentation, lesion location, treatment, rehabilitation guidance and outcome. RESULTS: Forty-five cases were identified during the period of study. Forelimb injuries predominated (35/45, 77.8%). Mean age of cases was 3.4 ± 1.3 years. Palpable clinical abnormality referable to the fetlock region was not a feature. The majority (35/45, 77.8%) of injuries were diagnosed with radiography (flexed dorsopalmar/plantar projection), with the remainder requiring magnetic resonance imaging (MRI) for diagnosis. Seven horses underwent surgery either at the time of original diagnosis or following reinjury. Twenty-eight of 30 horses (93.3%), not retired for unrelated reasons, returned to racing, with 5 (16.7%) conservatively managed horses sustaining reinjury at a median of 305 days. Misdiagnosis resulted in progression to catastrophic fracture in 2 cases. CONCLUSIONS: Clinical findings associated with unicortical condylar fractures can be mild and appropriate diagnostic imaging is necessary for injury detection. Failure to detect injury can lead to catastrophic fracture. Most cases respond to conservative management and return to racing, but risk of reinjury merits consideration of surgery in selected cases. Veterinary vigilance and timely intervention has the potential to considerably reduce the incidence of complete condylar fracture of the fetlock in the racehorse. The Summary is available in Chinese - see Supporting information.

Effects of local simvastatin-alendronate conjugate in preventing periodontitis bone loss.

BACKGROUND AND OBJECTIVE: Local host-modulation therapy is an emerging approach to prevent disease progression in sites with moderate periodontitis. The combination of simvastatin and alendronate would be an intriguing host-modulatory strategy because of the bone-anabolic properties of simvastatin and the antiresorptive/bone-targeting characteristics of alendronate. The objective of this study was to evaluate the effects of local administration of a simvastatin-alendronate-ß-cyclodextrin (SIM-ALN-CD) conjugate for preventing experimental periodontitis bone loss. MATERIAL AND METHODS: Twenty-four mature female Sprague-Dawley rats were treated with three, 12 µL injections, administered one week apart, bilaterally into the palatal/interproximal gingiva. The injections contained: (i) a conjugate of 0.5 mg of SIM and 3.75 mg of ALN-CD in H2 O; (ii) H2 O alone; or (iii) no treatment. One week later, the same sites were subjected to induction of experimental periodontitis by three injections (i.e. one injection administered every other day for five d) of 0.01 mg of Escherichia coli endotoxin [lipopolysaccharide (LPS)] in phosphate-buffered saline (PBS) or PBS alone. After an additional week, the rats were killed, the palates were harvested and interproximal bone volume and adjacent thickness were calculated using microcomputed tomography. Subsequently, specimens were decalcified, and interproximal histologic sections were stained with hematoxylin and eosin for evaluation of alveolar crest osteoclasts and surrounding inflammation. Values were compared among treatment groups using analysis of variance and the Kruskal-Wallis test. RESULTS: Interproximal bone volume was reduced by LPS injections (p ≤ 0.04), yet when experimental periodontitis was preceded by treatment with SIM-ALN-CD, more bone was preserved than after treatment with carrier alone (p = 0.007). While LPS caused a significant loss in bone thickness over the palatal roots (p ≤ 0.04), the injection protocol (PBS) also caused a significant loss of palatal bone thickness (p ≤ 0.03). However, prophylactic SIM-ALN-CD injections resulted in no further loss of bone thickness during experimental periodontitis. LPS injections gave histologic evidence of increased osteoclasts and subsulcular inflammation, both of which were reduced when preceded by treatment with SIM-ALN-CD (p ≤ 0.0002). CONCLUSION: The primary conclusion of this study was that locally applied SIM-ALN-CD has the potential to prevent episodes of periodontitis bone loss.

Necrosis of the femoral condyles in a four-week-old foal: clinical, imaging and histopathological features.

A 4-week-old Thoroughbred filly foal with a history of sepsis was evaluated for right hindlimb lameness. Bilateral femoropatellar and femorotibial joint effusions were detected. Ultrasonography and radiography of the right stifle revealed signs of joint collapse and periarticular swelling. Computed tomography revealed abnormalities in the bone density of the medial femoral condyle of the right hindlimb and lateral femoral condyle of the left hindlimb. Euthanasia was recommended based on the severity of the lesions. Gross and microscopic examinations revealed extensive separation of the articular-epiphyseal cartilage complex from the subchondral bone of the femoral condyles. The histological features suggest an ischaemic aetiology; comparisons are made with lesions of osteochondrosis and avascular necrosis of bone.

Low-field standing magnetic resonance imaging findings of the metacarpo/metatarsophalangeal joint of racing Thoroughbreds with lameness localised to the region: a retrospective study of 131 horses.

REASONS FOR PERFORMING STUDY: The metacarpo/metatarsophalangeal (MCP/MTP) joint is a common site of lameness in the Thoroughbred racehorse. Radiographs may fail to show pathology consistent with the degree of lameness. With a high incidence of stress fractures occurring in the distal third metacarpal/metatarsal (MC3/MT3) condyles and proximal phalanx, a definitive diagnosis as to the nature of the pathology is essential. OBJECTIVE: To describe the low-field magnetic resonance imaging (MRI) findings in Thoroughbred racehorses with MCP/MTP joint pain scanned under standing sedation. METHODS: The MR images and clinical records of all Thoroughbred racehorses undergoing MRI of the MCP/MTP joint between October 2006 and August 2010 were reviewed. A total of 168 joints from 131 horses were selected for inclusion. The MRI finding considered most significant in the lame (or lamest) limb was noted. RESULTS: Diagnostic quality images were obtainable in 97.8% of horses. The most common finding was palmar/plantar osteochondral disease in MC3/MT3 (54.9% of horses). Incomplete condylar fracture was diagnosed in 19.8% of horses, with the lateral condyle predominating. An incomplete sagittal fracure of P1 was diagnosed in 14.5% of horses and 11.4% were diagnosed with 'dorsal joint disease'. Other findings included transverse MC3 stress fractures (1.5%), soft tissue injuries (12.2%) and proximal phalangeal 'contusions' (3.8%). No significant bone/soft tissue injury was detected in 5.4% of cases. CONCLUSIONS: Standing MRI can detect a spectrum of disease within the MCP/MTP joints of racehorses. The procedure is well tolerated and may lead to a definitive diagnosis where radiographic imaging is inconclusive. POTENTIAL RELEVANCE: A total of 35.8% of cases had MRI findings consistent with fracture pathology, which could not be confirmed radiographically at the time of the MRI examination. This has important therapeutic and prognostic implications and may help to prevent catastrophic injury.

Use of multi-detector computed tomographic angiography in the diagnosis of a parapharyngeal aneurysm in a 6-week-old foal.

Multidetector-row computed tomographic contrast angiography (MDCTA) is routinely employed to investigate vascular masses in human patients but, to date, the use of this technique to investigate an aneurysmal mass has not been reported in an equine case. The potential of MDCTA to investigate a right-sided parapharyngeal mass in a 6-week-old Thoroughbred foal was therefore investigated. A 4-slice helical computed tomography scanner was used on a superficial, firm, ovoid mass yielding arterial blood on fine needle aspiration. MDCTA enabled identification of the vessels involved thus assisting in forming a diagnosis based on the morphology of the lesion and aided surgical planning. Histology confirmed the presence of mural thrombus and calcification within the smooth muscle wall consistent with a true aneurysm. MDCTA provided additional information to conventional imaging in this case of vascular masses of the head and neck. The technique therefore has the potential to improve diagnosis and assist in the management of such lesions.

Clinical and imaging features of suspected prodromal fracture of the proximal phalanx in three Thoroughbred racehorses.

Sagittal fracture of the proximal phalanx (P1) is an important musculoskeletal injury of the performance horse. Although widely considered to be monotonic in nature, there is emerging evidence that some P1 fractures may have stress-injury aetiology. Three cases are described in which imaging features found were suggestive of prodromal bone injury. All cases returned to full performance use after a period of rest. The authors conclude that it is possible that some P1 fractures in the Thoroughbred racehorse may develop through stress/fatigue injury pathways. It is proposed that intervention prior to overt fracture may be possible in some cases.

Standing magnetic resonance imaging detection of bone marrow oedema-type signal pattern associated with subcarpal pain in 8 racehorses: a prospective study.

REASON FOR PERFORMING STUDY: The proximal metacarpal region is a common site of origin of lameness in the performance horse. A number of disease entities are recognised as causes of proximal metacarpal lameness but a definitive diagnosis is often elusive. Magnetic resonance imaging (MRI) is hypothesised to offer advantages over traditional imaging modalities in the investigation of proximal metacarpal pain. OBJECTIVE: To describe clinical and imaging features of cases of lameness in racehorses arising from the proximal metacarpal region in which standing MRI identified 'bone marrow oedema-type' (BMO-type) signal patterns. METHODS: Records for all horses undergoing standing MRI of the proximal metacarpus/distal carpus from September 2006 to December 2008 were reviewed. Cases underwent a standardised protocol for diagnostic analgesia, radiography and ultrasonography of the proximal metacarpus and distal carpus. Cases with proximal metacarpal lameness displaying a characteristic BMO-type signal pattern on MRI were identified and outcomes analysed. RESULTS: Eight cases were identified with characteristic MRI findings of extensive hyperintensity on T2* gradient echo and short tau inversion fast spin echo sequences and corresponding hypointensity on T1 gradient echo images within the palmaroproximal aspect of the third metacarpal bone. Follow-up information was available for all cases; at the time of writing 7/8 had returned to full work and were free from lameness. CONCLUSIONS: The BMO-type signal patterns visible on MR images in these cases may signal the existence of a previously under-diagnosed pathological process associated with proximal metacarpal lameness in racehorses. This finding is postulated to be associated with a stress reaction and possible prodromal stress fracture of the palmaroproximal metacarpus not appreciable radiographically or ultrasonographically. POTENTIAL RELEVANCE: MRI of the proximal metacarpal region permits detection of pathological processes, which may elude conventional imaging and, therefore, has important therapeutic and prognostic implications in these cases.

Microscopic polyarteritis presenting with skin necrosis in a patient with sickle-cell disease.

A 20-year-old Caribbean woman with sickle cell anaemia was admitted with a 4-day history of fever and a painful swollen right ankle. She rapidly developed skin necrosis. The differential diagnosis is discussed. This case illustrates the difficulty in identifying the cause of cutaneous necrosis in an acutely ill patient. In our patient, histopathology implicated a vasculitic process, which was subsequently identified as a manifestation of microscopic polyarteritis.

Regulation of insulin-like growth factor-binding protein-3 ternary complex in feline diabetes mellitus.

The 140 kDa ternary complex of insulin-like growth factor-binding protein-3 (IGFBP-3), IGFs and an acid-labile subunit (ALS) has previously been shown to be decreased in diabetes mellitus in humans and rats. We have studied IGF-I levels and ternary complex formation in normal and diabetic cats. Total IGF-I concentrations, measured by RIA using des(1-3)-IGF-I as tracer were (+/-s.e.m.) 54+/-13 nmol/l in eight normal and 227+/-57 nmol/l in eight diabetic cats (P<0.01). The size-distribution of IGFBPs in the cat circulation was determined by incubation with (125)I-IGF-II and Superose 12 chromatography. In normal animals 26+/-2% of the (125)I-IGF-II were in a 140 kDa form compared with 48+/-5% in diabetic cats (P<0.01). When samples from normal and diabetic animals were co-incubated 52+/-3% were at 140 kDa. A similar shift was seen when normal cat and normal human serum were co-incubated. A 2-fold increase in the 140 kDa form in diabetic cats was confirmed first by size-fractionating samples and then performing a ligand-binding assay with (125)I-IGF-I or -II and charcoal separation. SDS-PAGE and Western ligand blotting demonstrated a 45 kDa doublet (presumably IGFBP-3) and 30-35 kDa forms. There were no apparent differences between normal and diabetic profiles on SDS-PAGE, suggesting that a proportion of IGFBP-3 which circulates 'free' in normal cats forms a ternary complex in the diabetic circulation. We conclude that (i) in contrast to humans and rats, ALS is the limiting factor for ternary complex formation in normal cats, (ii) ALS concentrations increase in feline diabetes mellitus and, by promoting ternary complex formation, this leads to an increase in total IGF-I concentrations, and (iii) total IGF-I concentrations may not be reliable in the diagnosis of acromegaly in diabetic cats.

Ten-year in vitro assessment of the surface status of three retrofilling materials.

Sixty-one maxillary central incisors were collected, cleaned, and divided into six groups of 10 teeth, with one tooth as a control. Half of the teeth were resected with a high-speed bur and half with a slow-speed bur, and prepared for retrofillings. Retrofillings of EBA cement and Ketac cement were placed in 10 teeth, each of the high-speed and slow-speed groups. Similarly++, zinc containing amalgam was placed in 10 teeth of the high-speed group, and zinc-free amalgam was placed in 10 teeth in the slow-speed group. A single operator completed all retrofills. They were stored in physiological saline for 10 yr. After that period, the apical portions were photographed at X 30 magnification and evaluated by the authors for marginal discrepancies, root crazing, staining, voids, and roughness. Overall, EBA cement++ and amalgam rated better than Ketac cement in every category except root crazing. Perhaps, as some studies have suggested, EBA cement may replace amalgam as the retrofill material of choice.

Endodontics: errors in instrumentation.

The authors provide a pictorial review of technical errors in endodontic instrumentation. Examples of separated instruments, abrupt constriction, laceration, canal transportation, and control zone errors are provided. The potential problems and effect on prognosis associated with these errors are explained.

Spontaneous apical closure of an avulsed immature incisor.

Apical closure of nonvital teeth can be achieved by appropriate endodontic intervention. A case is reported in which apical maturation appears to have occurred without treatment and in the presence of sporadic drainage from a sinus tract stoma.

Sodium hypochlorite injection into periapical tissues.

Sodium hypochlorite is a useful adjunct to endodontic therapy but it must be confined to the root canal. A case of periapical injection of hypochlorite with untoward sequellae is presented.

Recurrent knee pyarthrosis with intact hyaline cartilage. A case report.

A 20-year-old patient with hyperimmunoglobulin E and abnormal leukocyte chemotaxis was treated by synovectomy for chronic and recurrent staphylococcal knee pyarthrosis. The articular cartilage was noted to be preserved despite the severity of synovial involvement and the chronic nature of this case of septic arthritis. Polymorphonuclear leukocytes were few, despite florid Staphylococcus aureus growth. This observation lends support to the role of lysozomal enzyme activity from leukocytes in hyaline cartilage damage in pyarthrosis.