Synovial Fluid and Clinical Changes After Arthroscopic Partial Synovectomy of the Equine Middle Carpal Joint

Changes in synovial fluid and clinical variables after arthroscopic partial synovectomy of the middle carpal joint were studied in 12 normal horses. A 7 mm motorized synovial resector was inserted into each middle carpal joint; one middle carpal joint of each horse was randomly selected to have arthroscopic synovectomy (treated) and the opposite joint was lavaged (control). Lameness examinations and synovial fluid analyses were performed before operation and at 8, 14, 21, and 28 days after operation. Lameness variables did not differ between treated and control legs. Middle carpal and carpometacarpal joint circumference measurements were increased for 4 weeks. Synovial fluid specific gravity, pH, total protein, albumin concentration, and alpha-1-, beta- and gamma-globulin concentrations, at 8 and 14 days were significantly higher than before operation in both treated and control middle carpal joints. No significant differences were found between treated and control middle carpal joints at any time for color, clarity, pH, mucin clot formation, total protein, albumin, and globulin fractions. Arthroscopic partial synovectomy and lavage did not cause significant lameness and resulted in a synovitis indistinguishable from synovitis related to arthroscopic lavage alone.     

Rectal and Colonic Injury in the Llama Anatomic Considerations and Surgical Management in Four Llamas

Transrectal palpation in llamas can result in iatrogenic rectal and colonic injury. The purpose of this report is to define the caudal extent of the peritoneal cavity in llamas and to describe the surgical management of rectal or colonic injuries in four llamas. Measurements were made of six adult llamas during necropsy. The mean distance from the peritoneal reflection to the anus was 3.9 ± 0.1 cm (3.4 - 4.3 cm). Four llamas were examined for rectal or colonic perforations. One laceration was of partial thickness and three lacerations were of full thickness. Two of the defects were repaired by a transanal approach and two by celiotomy to facilitate removal of fecal debris and abdominal lavage. Successful repair of the rectal or colonic tears was achieved in all four llamas. Wound infection and incisional hernia occurred in both llamas that underwent celiotomy. Two llamas died 3 and 18 months later, and two llamas have survived 2 years. Rectal tears in llamas are accompanied by a high risk of peritoneal contamination, and primary closure is recommended. If fecal contamination of the abdomen has occurred, celiotomy is indicated to allow mechanical removal of fecal debris and peritoneal lavage.     

Replacement of the Medial Collateral Ligament with Polypropylene Mesh or a Polyester Suture in Dogs

The medial collateral ligament of one stifle in 20 adult dogs was excised and replaced with polypropylene mesh or a polyester suture. After 26 weeks, the fibrous tissue-prosthesis composites were evaluated clinically, morphologically, and biomechanically. Clinical lameness was not significantly different after 10 days. The polypropylene mesh reconstructions consistently had more fibrous tissue and greater collagenous ingrowth than the polyester suture reconstructions. There were four complications related to fixation of the polypropylene mesh prosthesis and one to the polyester suture. The polypropylene mesh reconstructions had greater stability and were biomechanically more similar to the natural ligaments than the polyester suture reconstructions. Although the results with polypropylene mesh were favorable, more challenging biomechanical testing and alternative anchoring techniques are required before polypropylene mesh can be recommended as a collateral ligament replacement in dogs.     

Repair of Facial Defects with Periosteal Flaps in Two Horses

Facial defects that extended into the sinuses of two horses were repaired by using adjacent periosteum to cover the defects, using either a single flap or double flap technique. Acceptable cosmetic appearance was restored in both horses. Resistance to penetration of a needle and ultrasonic scanning demonstrated bony bridging in one horse.     

Histologic Evaluation of Response to Implantation of Polyvinilidine Plates in Dogs and Rats

The effect of implantation of polyvinilidine spinal plates was studied when placed on spinous processes of 11 mixed breed dogs and when placed within the thoracolumbar musculature of 12 male white rats. Specimens were also obtained from soft tissues adjacent to polyvinilidine plates 2 to 3 months after clinical surgery to repair spinal subluxations in three dogs. A similar pattern of dense, organized fibrous tissue interspersed with focal congregations of lymphocytes, plasma cells, and multinucleated giant cells was observed in the dog experiment, rat experiment, and in all clinical cases. Birefringent debris with polarization patterns identical to small slivers of polyvinilidine was associated with the observed reactions. It would appear that either a chemical or physical characteristic of the plates elicited this foreign body reaction. Grooving the inner surface of the plates, which is performed to increase the friction grip when applied to spinous processes, may make the surface texture of the plate more reactive or it may predispose the surface of the plate to minute fragmentation ("wear products").     

THE EFFECT OF MANUAL LUNG INFLATION VS. SPONTANEOUS INSPIRATION ON THE CARDIAC SILHOUETTE IN ANESTHETIZED DOGS

The purpose of this study was to assess radiographic heart size in anesthetized dogs, comparing radiographs made with the patient breathing spontaneously to radiographs obtained using positive pressure manual lung inflation. The hypothesis was that manual inflation would cause reduction in the cardiac size. With dogs in right recumbency a radiograph was made at peak spontaneous inspiration followed immediately a radiograph made with application of positive pressure manual inflation of the thorax. Cardiac size was assessed, both subjectively and objectively using the vertebral heart scale (VHS). Two hundred and six dogs were studied. Manual inflation resulted in a significantly greater degree of lung inflation assessed radiographically ( P <0.0001). The subjectively assessed heart size was significantly smaller in radiographs made with manual inflation, leading to different subjective categorization of heart size in 67 (32%) of dogs. The objectively measured VHS was also significantly smaller in the radiographs made using manual inflation by a mean of 0.24 of a vertebral length (95% CL of mean difference: −0.29, −0.19, P <0.0001). A statistically significant reduction in subjective heart size and in VHS occurred with manual inflation of the lungs, and these differences may be clinically significant. Thus, if serial radiographs are obtained to assess cardiac size, the radiographic technique used should be the same.     

HEMATOMYELIA SECONDARY TO LUMBAR CEREBROSPINAL FLUID ACQUISITION IN A DOG

A 2-year-old male (Hungarian Vizsla) was evaluated for progressive discomfort of possible spinal origin. A minimum data base, thoracolumbar magnetic resonance (MR) imaging examination and electrophysiologic investigation were all normal. Cerebellomedullary and lumbar cerebrospinal fluid (CSF) was collected. The fluid was unremarkable except for elevated total protein. Shortly, thereafter, the dog had progressive neurologic deterioration referable to a caudal lumbar spinal cord lesion. In a repeated MR examination there was a well-circumscribed intramedullary lesion at the site where lumbar CSF was collected. The signal characteristics of the lesion were compatible with subacute hemorrhage, which was confirmed to be hematomyelia at the time of successful decompressive surgery.     

Removal of Five Canine Cardiac Tumors Using a Stapling Instrument

Cardiac tumors in five dogs, including four right atrial appendage hemangiosarcomas and one heartbase chemodectoma, were removed, and the excisional edges were closed with a thoracic-abdominal (TA) stapling instrument. All five dogs recovered from surgery and were discharged from the hospital within 4 days. The four dogs with atrial appendage hemangiosarcomas developed extensive metastasis, although no evidence of tumor recurrence was found at the surgical site in two dogs that were necropsied. The dog with a chemodectoma was alive with no clinical or radiographic evidence of recurrence or metastasis 17 months following surgery.     

Endoscopic Examination and Treatment of Paranasal Sinus Disease in 16 Horses

Sixteen horses with suspected paranasal sinus disease had endoscopic examination of the paranasal sinuses with a 4.0 mm arthroscope either while standing and sedated (14 horses) or under general anesthesia (two horses). Endoscopic diagnosis included sinusitis (four horses), sinus cyst (three horses), hemorrhage (three horses), neoplasia (three horses), and tooth root abnormalities (two horses). No abnormalities were detected in one horse. Endoscopic findings concurred with the radiographic findings in 13 horses (81%). Samples of sinus contents for bacteriologic (eight horses) and histologic examinations (five horses) were obtained using sinus endoscopy. Diagnostic sinus endoscopy was combined with debridement, lavage, and suction as a therapeutic technique in 10 horses. In three horses, sinus exploration was performed after diagnostic endoscopy confirmed sinus disease, whereas in three horses, further therapy was not recommended after sinus endoscopy. Clinical signs of sinus disease resolved in 11 horses (69%) overall and in eight of 10 horses (80%) with sinusitis, cyst formation, or hemorrhage using endoscopic techniques alone. Mild, local subcutaneous emphysema occurred at the portal sites in all horses, but healing occurred without additional complications, latrogenic damage to sinus structures occurred in one horse. Sinus endoscopy was useful in the diagnosis and management of paranasal sinus disease and avoided the need for exploratory sinusotomy in some horses.