Intraoperative facet joint injury during anterior cervical discectomy and fusion: an experimental study.

OBJECT: Disorders of the cervical spine can be successfully addressed by surgical intervention when the choice of such intervention takes into account the possible complications in the treated and adjacent structures. The aim of this study was to investigate the potential for intraoperative trauma in cervical zygapophysial joints and to describe possible pathological changes that may occur during cervical spine surgery. METHODS: Fifteen sheep underwent surgical intervention via an anterior cervical approach; discectomy at the C5-6 level was performed. In 10 animals, the discectomy was accompanied by titanium cage fusion. The sheep were killed immediately after completion of the operation. Radiological examination of the isolated cervical spines followed. Furthermore, the cervical spines were submitted to decalcification and incised using a microtome, and tissue sections were then studied using light microscopy. RESULTS: Radiological examination was used to assess vertebral alignment, vertebral body (VB) morphology, implant position, and endplate and facet joint gross morphology. Histological examination of the endplate and VB demonstrated degenerative lesions as well as cellular necrosis. The study of the facet joints at the treated as well as at adjacent segments (both above and below) revealed in some cases edema between the collagen fibers of the joint capsules, congestion, and microhemorrhages. Injuries were evident in animals in which the Caspar device was used. CONCLUSIONS: Histopathologically confirmed lesions occurred in facet joints while anterior cervical spine surgery was being performed in sheep. The findings were indicative of trauma and, in the case of human spine surgery, could possibly account for several postoperative complications and patient complaints.

Ocular manifestations of natural canine monocytic ehrlichiosis (Ehrlichia canis): a retrospective study of 90 cases.

OBJECTIVE: To investigate the spectrum, prevalence and treatment response rate of ocular manifestations associated with natural canine monocytic ehrlichiosis (CME) due to Ehrlichia canis. METHODS: The medical records of 90 dogs that were admitted for primary ocular problems and reacted positive for E. canis serum antibodies were reviewed. All the dogs were treated with oral doxycycline. In 79 dogs, a combination of systemic corticosteroids and/or topical anti-inflammatory, mydriatics/cycloplegics and antibacterial agents were applied. RESULTS: The dogs ranged from 0.5 to 15 years in age; 55 were male and 35 female. A total of 19 breeds were represented. In the majority of dogs, ocular abnormalities were noticed in conjunction with other CME-induced clinical signs. In 30/90 dogs, ophthalmic signs were the sole presenting complaint. Unilateral (22/90, 24.5%) and bilateral (68/90, 75.5%) uveitis was the most common ophthalmic diagnosis and was classified as anterior, posterior or panuveitis in 58 (64.5%), 8 (8.9%) and 24 (26.6%) of the dogs, respectively. Bilateral uveitis was significantly more common than unilateral uveitis (P < 0.0001), and anterior significantly more common than posterior uveitis (P < 0.0001) or panuveitis (P < 0.0001). In addition, corneal ulceration (12/90, 13.3%), necrotic scleritis (10/90, 11.1%), low tear production (8/90, 8.9%) and orbital cellulitis (3/90, 3.3%) were seen. Of the 45 (50%) dogs with a satisfactory follow-up, 25 (55.5%), 11 (24.5%), and 9 (20%) showed complete, partial and poor response to treatment, respectively. The number of dogs exhibiting complete resolution of the ocular manifestations was significantly higher than those with partial (P < 0.0001) or poor (P < 0.0001) response. CONCLUSIONS: CME should be considered a major differential for a wide range of ocular manifestations exhibited by dogs residing in the endemic areas of the disease. Anterior bilateral uveitis appears to be the most prevalent ocular lesion and a favorable outcome to systemic and topical treatment may be expected in the majority of the affected dogs.

Subconjunctival filariasis due to Onchocerca sp. in dogs: report of 23 cases in Greece.

In the present study, we describe a series of 23 cases of ocular subconjunctival parasitic granulomas in dogs, admitted to the Clinic of Surgery, Faculty of Veterinary Medicine of the Aristotle University of Thessaloniki, Greece, between 1997 and 2000. The ophthalmic manifestations in all animals were periorbital swelling, discomfort, photophobia, conjunctival congestion, and discharge. A more detailed examination revealed the presence of periocular masses (nodules) on the subconjunctival bulbar space. Granulomatous or cyst-like formations were extracted surgically, and were found to contain thread-like nematode parasites. A histologic and parasitologic examination of tissues and parasites was carried out. Diagnosis of parasitic granulomas was made and the parasite was identified as Onchocerca sp. This is the largest series of cases reported of aberrant Onchocerca infections in dogs coming from one geographic location.