Scapulohumeral subluxation and luxation in five alpacas.

INTRODUCTION: The patient histories, findings from clinical examinations, diagnostic imaging techniques, the surgical procedures, complications, necropsy findings and the outcomes from five male or castrated male alpacas with scapulohumeral sub-/luxation are presented. These alpacas each had a history of severe forelimb lameness for one week (n: 1), four weeks (n: 2) and for two-to-three months (n: 2). Two of the five alpacas were euthanized due to severe osteoarthritic changes that developed during the two-to-three months of scapulohumeral luxation. Three alpacas were treated with open reduction and internal stabilisation by placing tension band sutures between one 4,5 mm cortical screw anchored in the scapular neck and two 4,5 mm cortical screws anchored in the greater humeral tubercle, all of them provided with washers. Post-surgery a carpal flexion sling was applied to avoid postoperative weight-bearing. An exercise programme was started after removal of the carpal sling and continued for 12 weeks. In one of the three alpacas an additional non-displaced fracture of the acromion occurred two weeks after surgery. In conclusion, all three treated alpacas had good-to-excellent long-term outcomes and are still alive 123, 15 and 12 months after surgical repair of the scapulohumeral sub-/luxation. As four weeks, or even up to three months elapsed in four of these five alpacas until a definitive diagnosis was made, more education should be provided to alpaca owners that severely lame animals should be presented to a veterinarian with adequate diagnostic possibilities and expertise as soon as possible in order not to compromise treatment success.

INTRODUCTION: Dans cette étude rétrospective, on présente les antécédents des patients, les résultats des examens cliniques, les techniques d'imagerie diagnostique, les procédures chirurgicales, les complications, les résultats de l'autopsie et les résultats finaux de cinq alpagas mâles ou mâles castrés souffrant d'une subluxation ou luxation scapulo-humérale. Ces alpagas présentaient chacun des antécédents de boiterie sévère des membres antérieurs depuis une semaine (n: 1), quatre semaines (n: 2) et deux à trois mois (n: 2). Deux des cinq alpagas ont été euthanasiés en raison des changements arthrosiques graves qui s'étaient développés au cours des deux à trois mois de luxation scapulo-humérale. Trois alpagas ont été traités par réduction ouverte et stabilisation interne en plaçant des sutures à bande de tension entre une vis corticale de 4,5 mm ancrée dans le col de l'omoplate et deux vis corticales de 4,5 mm ancrées dans le tubercule huméral supérieur, toutes munies de rondelles. Après l'opération, une écharpe de flexion du carpe a été mise en place pour éviter la mise en charge postopératoire. Un programme d'exercices a été mis en place après le retrait de l'écharpe carpienne et a été poursuivi pendant 12 semaines. Chez l'un des trois alpagas, une fracture non déplacée de l'acromion s'est produite deux semaines après l'opération. En conclusion, les trois alpagas traités ont eu des résultats à long terme bons à excellents et sont toujours en vie 123, 15 et 12 mois après la réparation chirurgicale de la subluxation scapulo-humérale. Dans la mesure où il s'est écoulé quatre semaines voire jusqu'à trois mois chez quatre de ces cinq alpagas avant qu'un diagnostic définitif ne soit posé, il convient d'informer davantage les propriétaires d'alpagas que les animaux gravement boiteux doivent être présentés à un vétérinaire disposant des possibilités de diagnostic et de l'expertise adéquates le plus rapidement possible afin de ne pas compromettre le succès du traitement.

Surgical treatment of scapulohumeral subluxation in an alpaca (Vicugna pacos) using osteotomy of the acromion, open reduction and extracapsular tension sutures.

CASE HISTORY AND CLINICAL FINDINGS: A 3.3-year-old male alpaca, weighing 60 kg was referred for investigation of a severe left forelimb lameness of 4 weeks duration. A scapulohumeral subluxation had been diagnosed radiographically by the referring veterinarian. CLINICAL FINDINGS AND DIAGNOSIS: Based on clinical, ultrasonographic and radiographic findings the diagnosis of cranio-lateral subluxation of the left humeral head was confirmed. In addition, a full thickness lesion (approximately 1×1 cm) of the articular cartilage on the caudomedial aspect of the humeral head was diagnosed by arthroscopy. TREATMENT AND OUTCOME: Treatment included open reduction with internal fixation. Severe muscle contraction and local tissue fibrosis around the scapulohumeral joint (SHJ) required osteotomy of the acromion 3 cm proximal to the distal acromial edge, to allow adequate access. Internal stabilisation was achieved by placing tension band sutures between one cortical screw in the scapular neck and two cortical screws, with washers, craniolaterally on the greater tubercle of the humerus. Post-surgery, a carpal flexion sling was applied with the carpus maintained in 70° flexion for 4 weeks to avoid postoperative weight-bearing. An exercise programme was started 8 days after surgery and continued for 12 weeks. The alpaca had an uneventful postsurgical recovery and showed no lameness after 8 weeks. The long-term outcome was excellent; 21 months after surgery the alpaca was sound and the range of movement of the left SHJ was equal to the right SHJ. CLINICAL RELEVANCE: Even in this chronic case of subluxation of the SHJ of 4 weeks duration, surgical treatment using osteotomy of the acromion, open reduction and internal fixation with extracapsular scapulohumeral tension sutures resulted in an excellent long-term outcome in this alpaca, despite the presence of a cartilage lesion.

Cervical spinal chordoma with chondromatous component in a dog.

A 7-year-old male Belgian Shepherd dog was presented with sudden onset of lateral recumbency and tetraparesis. At the level of the third cervical vertebra, magnetic resonance imaging demonstrated an intrameningeal and intramedullary mass lesion. The animal was subsequently euthanatized. A necropsy revealed a semitranslucent solid mass infiltrating dorsal and ventral dura mater and the spinal cord. Histologic examination revealed a lobulated pleomorphic mass, mainly resembling undifferentiated cartilage interspersed by spindle-shaped and polygonal cells with highly vacuolated cytoplasm (physaliphorous cells). Immunohistochemistry of the tumor cells demonstrated dual expression of vimentin and cytokeratin. Based on the histologic and immunohistochemical results, the diagnosis of a chordoma with chondromatous component was made.

Traumatic avulsion fracture of the lesser trochanter in a dog.

A 15-month-old 25 kg female spayed American Staffordshire Terrier was examined to determine the cause of a six month period of lameness of the left pelvic limb. Signs of severe pain were evident on hyperextension and simultaneous internal rotation or abduction of the left hip joint; crepitus or instabiltiy was not detected. The diagnosis of avulsion fracture of the lesser trochanter was based on radiographs, computed tomography (CT) and magnetic resonance imaging (MRI), supported by initial findings such as lameness and hip joint pain in extension. The dog was treated with strict confinement for eight weeks followed by a gradual increase in activity; non-steroidal anti-inflammatory drugs were given for one month. Three months later, the dog was clinically sound and unrestricted activity was resumed. Soundness was confirmed on follow-up 18 months after injury. CT and especially MRI were powerful diagnostic tools to identify chronic iliopsoas strains with an avulsion fracture of the lesser trochanter. Complete recovery ensued following conservative treatment only, despite the proximal diplacement of an avulsed segment of the lesser trochanter. Thus, traumatic injury to the iliopsoas muscle and to the lesser trochanter should be included as differential diagnosis in cases of hind leg lameness.