Katja Voss

Probable lumbar acute non-compressive nucleus pulposus extrusion in a cat with acute onset paraparesis

A spinal cord lesion localised caudal to the L6 spinal segment was diagnosed in a 2-year-old female spayed domestic longhair cat with acute onset paraparesis. Magnetic resonance imaging findings were consistent with an acute, non-compressive nucleus pulposus extrusion of the L5–L6 intervertebral disc. The cat was successfully managed with supportive care, including cage confinement.

Tibial tuberosity transposition-advancement for lateralization of the tibial tuberosity: An ex vivo canine study

OBJECTIVESnTo evaluate the degree of lateralization achievable and strength of tibial tuberosity transposition and advancement (TTTA) relative to pin and tension band wiring (PTBW) for lateral tibial tuberosity transposition.nnnMETHODSnSix pairs of cadaveric tibiae were used. Tibial tuberosity position was determined with computed tomography (CT); bones were then randomly assigned into TTTA and PTBW groups. The PTBW group had a tibial tuberosity osteotomy and fixation with pin and tension band wiring. The TTTA group had a tibial tuberosity advancement performed with lateralization of the tibial tuberosity by 50% of cage depth, using spacers on the cranial cage screw. Postoperative CT images showed lateralization and craniocaudal deviation. Single axial distractive loading was applied to the patella at 90˚ to the tibial plateau, and peak load, energy, and stiffness were calculated.nnnRESULTSnThere were significant differences in lateralization (PTBW: 67.92 ± 5.1 %; TTTA: 88.51 ± 5.5 %) (p = 0.0173) and craniocaudal deviation (PTBW: -8.30 ± 1.4 %; TTTA: 6.83 ± 0.6) (p = 0.0001). There were no significant differences in peak load to failure (N) (PTBW: 1448 ± 121; TTTA: 1597 ± 43) (p = 0.4541), energy to failure (N/mm) (PTBW: 15013 ± 2719; TTTA: 17314 ± 887) (p = 0.646), or stiffness (N/mm)(PTBW: 102.8 ± 4.7; TTTA: 92.9 ± 4.8) (p = 0.2716).nnnCLINICAL SIGNIFICANCEnThe TTTA was more effective at lateralization of the tibial tuberosity, and of comparable strength to PTBW. Greater support of the osteotomized fragment with TTTA may resist cyclic loading, and requires evaluation.

Influence of plate-bone contact on cyclically loaded conically coupled locking plate failure

INTRODUCTIONnThe maintenance of friction between locking plates and bone is not essential, so that they can be applied with a gap between the plate and underlying bone. We hypothesised that the presence of a gap under a locking plate with a conical coupling mechanism would reduce fixation stability or allow uncoupling of the locking screws from the plate.nnnMATERIALS AND METHODSnLocking plates with two conically coupled locking screws were applied to 6 pairs of adult canine femora. One of each pair had plate to bone contact and the contralateral construct had a 2 mm plate to bone gap. Constructs were cyclically loaded in cantilever bending with 10 percent incremental increases every 1000 cycles at 2 Hz, starting at 250 N. The constructs were fatigued to failure. To evaluate fatigue life of the conical coupling, testing was repeated with aluminium tubing replacing the bone, to eliminate screw-bone cutout failure.nnnRESULTSnThe mean sustained loads and cycles to failure in the contact group (420.80, standard error [SE] 14.97 N; 7612.00, SE 574.70 cycles) were significantly greater than in the gap group (337.50, SE 14.97 N; 4252.00, SE 574.70 cycles), (p<0.001). Failure mode of all bone constructs was via screw cutout from the bone. Aluminium tubing constructs failed via screw or plate fatigue and breaking, with one construct having elevation of the plate over the screw head.nnnDISCUSSION AND CONCLUSIONSnElevation of locking plates with a conical coupling system by 2 mm from the bone reduced construct fatigue life but did not result in screw head uncoupling from the plate.

Atypical, abscessated nasopharyngeal polyp associated with expansion and lysis of the tympanic bulla:

A 5-year-old, male neutered domestic shorthair cat was referred for investigation of lethargy, weight loss, pyrexia and upper respiratory tract signs. On computed tomography, an expansile, osteodestructive lesion in the right tympanic bulla was identified. A soft tissue mass extended from the bulla into the nasopharynx, cranium and subcutaneous tissues. The nasopharyngeal mass ruptured during handling, liberating purulent material from which Pasteurella multocida was isolated in pure culture. The lesion was most likely an atypical, abscessated nasopharyngeal polyp. The cat was treated with bulla osteotomy and antibiotics, and made a complete recovery.

Association of mineralisations in the stifle joint of domestic cats with degenerative joint disease and cranial cruciate ligament pathology.

Objectives The aim of the study was to evaluate the prevalence, size, location and appearance of mineralisations in feline stifle joints, and to evaluate their relationship with osteoarthritis and cranial cruciate ligament (CrCL) status. Methods Presence or absence, and size of mineralisations were determined from lateral stifle radiographs of 25 cats with CrCL rupture, and 44 cat cadavers without CrCL rupture. Mineralisations were classified as small, medium or large. Prevalence was compared between the clinically affected cats and the cadavers; the cadaver group was subdivided into an age-matched and an older group. Ten stifles with varying sizes of mineralisations were prepared as whole-knee specimens for histopathology. Location and appearance of the mineralisations, and degenerative changes in the cruciate ligaments, menisci, articular cartilage and joint capsule are described. Results Prevalence of articular mineralisations was 0.76 in stifles of cats with CrCL rupture (mean ± SD age 8.6 ± 4.5 years), 0.64 in stifles of age-matched cat cadavers and 0.74 in older cat cadavers (mean ± SD age 17.0 ± 2.4 years). Cats with CrCL rupture had a higher percentage of medium and large mineralisations than cats without CrCL rupture. Microscopically, small mineralisations were calcifications usually located in the cranial horn of the medial meniscus. Larger mineralisations were found to be ossifications, commonly located in the joint capsule and fat pad. Cats with larger mineralisations showed more signs of osteoarthritis, including degenerative changes in the CrCL. Conclusions and relevance Mineralisations in feline stifle joints were found to differ in size, appearance and location. Small mineralisations were usually confined to the medial meniscus, as described previously; larger mineralisations tended to be located in the tissues cranial to the menisci and seemed to be associated with osteoarthritis and CrCL pathology. Large mineralisations in feline stifles are ossifications in periarticular tissue and are associated with degenerative joint disease.

Aldosterone and progesterone-secreting adrenocortical adenocarcinoma in a cat with a concurrent meningioma

Case summary A 12-year-old, male neutered domestic shorthair cat was referred for investigation of suspected hyperaldosteronism due to persistent hypokalaemia, hindlimb ataxia, weakness of 1 month’s duration and a left adrenal mass that was detected on abdominal ultrasound. Neurological examination findings at referral were suggestive of a concurrent left forebrain lesion. Hyperaldosteronism and concurrent hyperprogesteronism were confirmed on endocrine testing. On computed tomography (CT) of the abdomen and thorax there was no evidence of local vascular invasion by the adrenal mass or of metastatic disease. CT and magnetic resonance imaging featured a large, focal rim-enhancing extra-axial left forebrain lesion consistent with a meningioma. Surgical excision of the forebrain mass was followed by adrenalectomy 2 weeks later. The tumours were classified on histopathology as a psammomatous meningioma and an adrenocortical adenocarcinoma, respectively. Immunohistochemical staining of the meningioma confirmed the presence of progesterone receptors. The cat remains well 2 years later. Relevance and novel information In humans, elevated serum progesterone levels have been associated with rapid growth of meningiomas due to the presence of progesterone receptors on the tumour. This is the first report of a cat with a progesterone and aldosterone-secreting adrenocortical adenocarcinoma and a concurrent meningioma. Clinicians should be aware of the potential effect of elevated progesterone on meningiomas in cats.

Effect of proximal translation of the osteotomized tibial tuberosity during tibial tuberosity advancement on patellar position and patellar ligament angle

BackgroundCranial cruciate ligament insufficiency is a common orthopaedic problem in canine patients. This cadaveric and radiographic study was performed with the aim of determining the effect of proximal translation of the tibial tuberosity during tibial tuberosity advancement (TTA) on patellar position (PP) and patellar ligament angle (PLA).ResultsDisarticulated left hind limb specimens harvested from medium to large breed canine cadavers (nu2009=u20096) were used for this study. Limbs were mounted to Plexiglass sheets with the stifle joint fixed in 135° of extension. The quadriceps mechanism was mimicked using an elastic band. Medio-lateral radiographs were obtained pre-osteotomy, after performing TTA without proximal translation of the tibial tuberosity, and after proximal translation of the tibial tuberosity by 3mm and 6mm. Radiographs were blinded to the observer for distance of tibial tuberosity proximalization following radiograph acquisition. Three independent observers recorded PP and PLA (tibial plateau method and common tangent method). Comparisons were made between the stages of proximalization using repeated measures ANOVA. Patellar position was found to be significantly more distal than pre-osteotomy, if the tibial tuberosity was not translated proximally (Pu2009=u20090.001) and if it was translated proximally by 3mm (Pu2009=u20090.005). The difference between pre-osteotomy PP and 6mm proximalization was not significant. The PLA was significantly larger if the tibial tuberosity was not translated proximally compared to tibial tuberosity proximalization of 6mm using the tibial plateau and the common tangent methods (Pu2009=u20090.006 and Pu2009=u20090.015 respectively).ConclusionsProximalizing the tibial tuberosity during TTA helps in maintaining vertical position of the patella in the patellar groove. Proximalization of the tibial tuberosity reduces PLA when compared to TTA without tibial tuberosity proximalization.

Type III hemifacial microsomia in a kitten

The case described herein presented with craniofacial malformations resembling hemifacial microsomia (HFM), a congenital disorder described in humans. To our knowledge, this is the first reported case of HFM in a domestic cat.

Partial carpal arthrodesis using a medially applied mini-plate in three cats with carpometacarpal hyperextension injury

Hyperextension injury to the feline carpus usually results in disruption of the palmar ligament support at the level of the carpometacarpal joint. Treatment options include pancarpal or partial carpal arthrodesis. Partial carpal arthrodesis preserves range of motion of the antebrachiocarpal joint, and pronation and supination of the forearm. The surgical technique and three cases of partial carpal arthrodesis using medially applied mini-plates are described. Partial carpal arthrodesis of the feline carpus using medially applied mini-plates may be a safe and effective treatment for hyperextension injury to the carpometacarpal joints.

Urethral defect with suspected corpus spongiosum herniation as a cause of stranguria and urethral haemorrhage in a dog

A male neutered Staffordshire bull terrier presented for evaluation of urethral haemorrhage of three days duration. A urethral mass was identified on contrast radiography, ultrasonography and urethroscopy. An open excisional biopsy was performed and the mass appeared to arise from the vascular tissue beneath the urethral wall. Histopathology revealed evidence of ulceration and granulation; coupled with the clinical findings the mass appeared to be a herniation of corpus spongiosum through a defect in the urethral mucosa. Removal and closure of the urethral defect, along with postoperative propranolol, effected a clinical resolution. To the authors knowledge, a urethral mucosal defect as a cause of urethral haemorrhage has not been previously described in the dog.