Colin W. Sereda

Long‐Term Efficacy of a Percutaneously Adjustable Hydraulic Urethral Sphincter for Treatment of Urinary Incontinence in Four Dogs

OBJECTIVE To evaluate the efficacy of a surgically placed, static hydraulic urethral sphincter (SHUS) for treatment of urethral sphincter mechanism incompetency (USMI). STUDY DESIGN Prospective study. ANIMALS Spayed female dogs (n=4) with acquired USMI. METHODS Urinary incontinence was assessed using a subjective continence score before and after implantation of an SHUS on the proximal urethra via ventral median celiotomy. Dogs were assessed for urinary continence, urinary tract infections, and implant-associated complications for 30 months. Residual incontinence was treated with percutaneous inflation of the SHUS with sterile saline solution through a biocompatible subcutaneous administration port. RESULTS At last follow-up (26-30 months after surgery), continence scores improved from a median preoperative score of 3/10 to a median postoperative score of 10. One dog developed wound drainage over the subcutaneously placed administration port but remained continent after port removal. Three occluders were percutaneously filled with additional saline (median, 0.18 mL; mean, 0.16 mL) to improve continence after surgery. CONCLUSIONS Application and adjustment of an SHUS provided sustained improvements in continence score in all dogs. CLINICAL RELEVANCE In this pilot study, 3 of 4 dogs with hydraulic urethral sphincter implantation had successful percutaneous adjustment and maintained improved continence scores for 2 years after surgery. Continence was maintained in the 4th dog even after administration port removal. Based on this pilot study, the SHUS warrants further clinical evaluation for treatment of dogs with USMI unresponsive to medical management.

Stabilisation of metacarpal or metatarsal fractures in three dogs, using circular external skeletal fixation

Abstract CASE HISTORY: Three dogs that presented with multiple metacarpal or metatarsal fractures, between January 2004 and November 2008. CLINICAL FINDINGS: Case 1 had sustained closed fractures of metacarpal bones II–V, resulting in a valgus angulation of the manus. Case 2 had 2-week-old open, infected, comminuted diaphyseal fractures of metatarsal bones II–IV. Case 3 had sustained open fractures of metacarpal bones II–V, that were initially stabilised with intramedullary Kirschner wires, but had gone to non-union 5 months after the initial surgery. TREATMENT: Circular external skeletal fixation was used in each of the three dogs. In Case 1, the fixator was used to perform a closed reduction, to align the overridden, angulated fractured metacarpus, by distracting the frame. In Case 2, the fixator was applied after a limited open reduction, and was used to provide stable fixation of the comminuted infected fractures while facilitating open wound management. In Case 3, the fixator was applied in buttress fashion, following open debridement and placement of an autogenous cancellous bone graft at the non-union fracture sites. CLINICAL OUTCOME: All three dogs developed drainage tracts from the fixator wire. There was minimal associated lameness or pain in two of the dogs, but Case 3 developed a transient lameness ascribed to infection associated with the wire tracts, which resolved following administration of antibiotics. Inflammation of wire tracts resulted in the fixator being removed prior to radiological evidence of union of all fractures in each dog, and the mean time from surgery to removal of the frame was 12 (range 7–24) weeks. None of the dogs had residual lameness or discomfort associated with the fractures at the time of long-term evaluation, which ranged from 10–45 months following surgery. CLINICAL RELEVANCE: These three cases illustrate the utility of circular external skeletal fixation for the stabilisation of complicated fractures of the metacarpus and metatarsus. The fixators were applied without inducing substantial iatrogenic trauma, and the small-diameter fixation wires provided effective stability of the short metacarpal and metatarsal fracture segments, allowing the fractures to heal. Although complications associated with wire tracts should be anticipated, circular external skeletal fixation should be considered as a viable method for managing complex fractures of the metacarpus and metacarpus in dogs.

Association between methicillin-resistant Staphylococcus pseudintermedius carriage and the development of surgical site infections following tibial plateau leveling osteotomy in dogs

OBJECTIVE To evaluate the association between preoperative carriage of methicillin-resistant Staphylococcus pseudintermedius (MRSP) and the development of surgical site infections (SSIs) following tibial plateau leveling osteotomy (TPLO) in dogs. DESIGN Prospective multicenter study. ANIMALS 549 dogs. PROCEDURES At 7 veterinary hospitals, swab specimens were obtained from the pharynx, nares, rectum, and skin of dogs admitted for TPLO. Specimens were submitted for culture of MRSP. For each dog, information regarding preoperative and postoperative antimicrobial administration, comorbidities, contact with other dogs, and whether the dog developed an SSI was obtained. Univariable and multivariable analyses were performed to identify variables associated with preoperative and postoperative MRSP colonization and the development of an SSI. RESULTS Of the 549 study dogs, 24 (4.4%) were identified as MRSP carriers before TPLO and 37 (6.7%) developed an SSI after TPLO. Bacteriologic culture was performed on specimens obtained from 32 of the 37 SSIs, and MRSP was isolated from 11 (34%). Carriers of MRSP (OR, 6.72; 95% confidence interval [CI], 2.12 to 21.4) and Bulldogs (OR, 11.1; 95% CI, 2.07 to 59.3) were at risk for development of an SSI after TPLO, whereas postoperative administration of antimicrobials (OR, 0.36; 95% CI, 0.15 to 0.91) appeared to protect against development of an SSI. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that carriage of MRSP were a risk factor for development of an SSI after TPLO and measures to rapidly identify and treat MRSP carriers are warranted. Postoperative administration of antimicrobials protected against development of an SSI after TPLO.

Use of an interlocking nail-hybrid fixator construct for distal femoral deformity correction in three dogs

Our purpose was to report the use of an interlocking nail-hybrid external fixator construct to correct distal femoral deformities in three dogs. Radiographs, computed tomography and a three-dimensional model were used to plan the surgical procedure. A femoral osteotomy or ostectomy was performed at the level of the centre of rotation of angulation in all three dogs. Angular and rotational deformities were corrected acutely. Distraction osteogenesis was performed to lengthen each femur postoperatively. All three dogs had additional anatomic abnormalities of the affected hindlimb complicating the correction of the distal femoral deformity. While the interlocking nail-hybrid fixator construct allowed for stable distraction of the femur, all three dogs developed complications during the postoperative convalescent period, and each had some degree of residual lameness. Lengthening the femur following acute deformity correction is problematic and additional experimental and clinical studies are warranted to decrease postoperative morbidity and improve functional results.

Use of hinged circular fixator constructs for the correction of crural deformities in three dogs.

BACKGROUND Hinged circular external skeletal fixator constructs are used to perform sequential correction of angular limb deformities, often with resultant limb segment lengthening, via distraction osteogenesis. Although there are several reports describing the use of these constructs for correction of antebrachial deformities in dogs, there is little information regarding their use on other limb segments. This report describes the use of hinged circular fixator constructs for the correction of acquired crural deformities in three skeletally immature dogs. CASE REPORTS Two dogs had purely frontal plane deformities (one valgus, one varus) and the third dog had frontal (valgus) and sagittal (recurvatum) components to its deformity. At the time of long-term evaluation, frontal plane angulation relative to the contralateral limb improved from 40° to 22° of valgus, 30° to 5° of valgus, and 20° to 1° of varus in the three individual dogs. Tibial length discrepancies of 12% and 22% that were initially present in two dogs were improved to 6% and 10%, respectively, of the contralateral tibial length at the time of final evaluation; both dogs had compensatory growth of the ipsilateral femur and all dogs had an excellent functional outcome. CONCLUSION These cases illustrate the value of using hinged circular fixator constructs for correction of crural angular deformities, particularly when length discrepancies of the tibia are present.