Veterinary Surgery最新文献

Objective: To evaluate if high-volume lavage results in a negative bacterial culture of egress fluid, regardless of pathogen in an experimental model of equine septic arthritis.

Study design: Experimental study.

Animals: A total of 11 horses in three groups (lipopolysaccharide [LPS] Group 1, n = 4; Escherichia coli [E. coli] Group 2, n = 4; Staphylococcus aureus [S. aureus] Group 3, n = 3).

Methods: A middle carpal joint of each horse was injected with LPS (synovitis Group 1), E. coli (septic arthritis Group 2) or S. aureus (septic arthritis Group 3). Arthroscopic lavage of the middle carpal joint was performed 24-h post-injection. Egress fluid samples were collected every liter for bacterial culture. Liter samples 1, 5, 10, 15, and 20 were submitted for bacterial culture. Subsequent samples were submitted based on the results of the initial dataset.

Results: Predicted probability of a positive culture after 1, 5, 10, 15, and 20 L for E. coli and S. aureus, respectively were: 44.7% (p = .04) and 98.3% (p ≤ .001) after 1 L, 42.6% (p = .02) and 94.3% (p ≤ .001) after 5 L, 40.1% (p = .02) and 77.8% (p = .001) after 10 L, 37.6% (p = .04) and 42.5% (p = .08) after 15 L, and 35.2% (p = .09) and 13.5% (p = .32) after 20 L. LPS cultures (n = 4) were negative at every timepoint. Post-lavage 50% (2/4) of E coli. and 100% (3/3) S. aureus horses had positive synovial fluid cultures.

Conclusion: A total of 20 L of lavage fluid was not sufficient to result in a sustained negative bacterial culture.

Clinical significance: High-volume arthroscopic lavage alone is not sufficient as a treatment for septic arthritis.

Objective: To compare the feasibility and biomechanical stability of two surgical techniques for fixation of vertical plane fractures of the accessory carpal bone (ACB).

Study design: Randomized experimental ex vivo study.

Sample population: Eight equine accessory carpal bones were included in a control group. A total of 20 equine cadaveric forelimbs were randomly assigned into two groups (n = 10 per group).

Methods: Vertical plane fractures were created palmar to the extensor sulcus using an oscillating saw. In Group 1 (CS), fractures were stabilized with two 4.5 mm cortical screws in lag fashion. In Group 2 (XP), fixation included one 4.5 mm cortical screw in lag fashion and a laterally applied angular stable X-plate with four 2.7 mm locking screws. Control ACBs were excised and tested under axial compression using a four-column testing machine. Postoperative specimens in Groups CS and XP were tested under the same conditions. The failure mode was assessed radiographically.

Results: The mean maximum strength of native bone was 11.26 (±2.14) kN. Two constructs per group were excluded due to cortical screw protrusion. No difference in failure load was observed (CS: 6.82 [±2.34] kN; XP: 8.02 [±1.10] kN; p = .7558). Failure mode analysis revealed a greater fracture gap size (p = .0039) and implant bending in CS specimens (p = 1.074e-7).

Conclusion: Both techniques were feasible, though neither restored native bone strength.

Clinical significance: A lateral X-plate with a single cortical screw demonstrated equivalent biomechanical performance to two cortical screws and was technically less demanding, offering a simpler fixation option for ACB fractures.

Objective: To evaluate the rate of residual polystomatic sublingual acinar tissue if tunneling dorsal to the digastricus muscle and dissection to the sublingual caruncle is not performed during mandibular-sublingual sialadenectomy in cats.

Study design: Cadaveric study.

Sample population: A total of 10 feline cadavers.

Methods: Mandibular-sublingual sialadenectomy was performed bilaterally in 10 feline cadavers using a ventral or ventrolateral approach in a randomized fashion. Salivary ducts were dissected as far rostral as possible with retraction of the masseter and digastricus muscles until they traveled dorsal to the digastricus muscle, where a ligature was applied. The position of the lingual nerve was identified. Following tunneling, dissection continued rostrally to the sublingual oral mucosa, where ducts were excised. Histology of dissected tissue rostral to the ligature was performed.

Results: Histology identified evidence of salivary acinar tissue in 13/19 (68.4%) specimens - 7/10 (70.0%) of specimens obtained with the ventral approach and 6/9 (66.7%) of those obtained with the ventrolateral approach (p > .99). In all cases, the lingual nerve was identified with retraction of the masseter and digastricus muscles without tunneling.

Conclusion: Tunneling dorsal to the digastricus muscle exposed additional polystomatic salivary acinar tissue in most cases.

Clinical significance: Tunneling dorsal to the digastricus via a ventral or ventrolateral approach may decrease the rate of polystomatic sublingual acinar tissue being left in situ in clinical cases.

Objective: To determine whether radiographic templating of femoral stem size for total hip arthroplasty (THA) using extended and flexed hip radiographs are interchangeable.

Study design: Retrospective radiographic study.

Sample population: A total of 25 dogs evaluated as THA candidates.

Methods: Hip-extended and hip-flexed radiographs were templated for femoral stem implant size by three surgeons. A fourth investigator measured femoral length, canal flare index (CFI), and osteoarthritis scores for each projection and recorded implant size from surgical records. Templated stem sizes from each projection were compared with the implanted stem sizes using Bland-Altman analysis. Descriptive statistics were reported based on data distribution.

Results: Templated femoral stem size differed between surgeons (p = .014); the median (IQR) stem size was #9 (8-10) for one surgeon, compared to #8 (7-9) for the other surgeons. Templated stem sizes on extended and flexed radiographs were #8 (7-9) and #9 (7-9), respectively (p < .0001). The mean (SD) CFI in extended and flexed projections were 1.61 (0.21) and 1.89 (0.30), respectively (p < .0001). Implant size was underestimated using the extended projection (mean difference: -0.54) and overestimated using the flexed projection (mean difference: 0.30). Positive proportional bias was present between the extended and flexed projections (slopes: 0.22 and 0.25; p < .003).

Conclusion: Neither templating method consistently predicted the clinical femoral stem implant size.

Clinical significance: Hip-flexed templating may serve as a practical alternative when extended projections are not possible, though intraoperative assessment remains essential for final implant selection, particularly since measurement bias increased for stems larger than size 9.

Objective: To report the outcomes of titanium mesh (TM) cranioplasty without polymethylmethacrylate (PMMA), incorporating a deliberate gap between the foramen magnum decompression (FMD) surface and the TM, in small-breed dogs with Chiari-like malformation and syringomyelia (CM/SM).

Study design: Retrospective clinical study.

Animals: A total of 87 client-owned small-breed dogs diagnosed with CM/SM by magnetic resonance imaging, all presenting with neurologic deficits.

Methods: All dogs underwent modified FMD. A gap was preserved between the FMD surface and the TM to facilitate tissue integration and reduce postoperative compressive forces. Clinical status was assessed based on neurologic improvement, medication dependency, and need for revision surgery.

Results: Surgical decompression with the modified TM technique resulted in sustained clinical improvement in most dogs. A total of 76 dogs (87%, 76/87) showed long-term improvement, and no revision surgeries were required during a median follow-up of 35 months (range: 27-73 months). Follow-up evaluation comprised postoperative computed tomography (CT) imaging at 6 months, as well as structured telephone interviews with owners to monitor clinical status. Only a small subset of dogs (13%, 11/87) required continued medication after surgery due to recurrence of signs.

Conclusion: Retrospective analysis showed that the modified TM technique, using a deliberate gap, was safe and effective in small-breed dogs with CM/SM, successfully preserving the decompression space and maintaining long-term neurologic stability.

Clinical relevance: The modified TM technique approach achieves durable neurologic improvement and minimizes long-term complications in small-breed dogs, demonstrating practical utility in managing this clinically challenging population.

Objective: To compare implant failure and gap displacement characteristics of simulated medial mid-body proximal sesamoid bone (PSB) fractures repaired with bone-screw-fasteners (BSF) or cortical screws (CS) in single or double screw configurations.

Study design: Ex vivo experimental study.

Sample population: A total of 14 paired equine cadaver forelimbs.

Methods: Medial mid-body PSB osteotomies were created in each forelimb. Surgical repair was performed using either: (1) single 3.5 mm BSF (BSF_single), (2) single 4.5 mm CS (CS_single), (3) two 3.5 mm BSFs (BSF_double), or (4) two 3.5 mm cortical screws (CS_double) (n = 7 repairs/group). Biomechanical properties and failure characteristics were evaluated through a single cycle to failure. Comparisons between groups were made using Wilcoxon-matched pairs or Mann-Whitney tests. Statistical significance was p < .05.

Results: The BSF_double group (2081 ± 181 N) had significantly higher yield than BSF_single (1458 ± 92 N, p = .01) and CS_single (1532 ± 86 N, p = .02) groups. The CS_double group (2101 ± 126 N) had significantly higher yield than BSF_single (p = .001) and CS_single (p = .003) groups. Biomechanical properties were not different between BSF_single and CS_single groups, or between BSF_double and CS_double groups. Gap measurements at construct failure were significantly higher abaxially than axially in all groups (all p < .05).

Conclusion: No differences were detected between the single BSF and 4.5 mm CS for repair of medial mid-body PSB fractures. Surgical repair using two screws has biomechanical advantage to single screw repair, regardless of screw type ex vivo.

Clinical significance: The BSF is not different to CS for repair of PSB fractures. Counteracting abaxial forces in surgical repair of mid-body PSB fractures warrants further investigation.

Objective: To evaluate postoperative racing performance of a population of Standardbred racehorses following arthroscopic removal of an osteochondrosis dissecans (OCD) lesion of the femoropatellar joint.

Study design: Retrospective study.

Sample population: A total of 45 client-owned Standardbred racehorses.

Methods: OCD lesions were measured and graded using the length of the subchondral bone defect from preoperative radiographs. Postoperative racing results were obtained from the United States Trotting Association, and follow-up owner surveys were conducted. A control group of contemporaneous paternal siblings free of OCD lesions was selected for comparison of racing performance. Regression analysis was used to determine associations between presence or grade of OCD lesions and performance parameters with sex and gait covariates.

Results: There was no significant difference in proportion of horses starting a race based on OCD lesion grade. Affected racehorses had fewer starts at 3 years of age (IRR = 0.84 [95% CI: 0.74-0.96], p = .012) but not at 2 years of age, when compared to unaffected siblings. There was also no difference in race wins or earnings between affected and unaffected horses.

Conclusion: Arthroscopy remains an effective treatment for OCD lesions of the femoropatellar joint in Standardbred racehorses, when performed prior to the start of intensive training, and lesions treated in this manner have no major impact on racing potential. Limitations included a small number of affected individuals especially with higher grades of OCD lesions and there was no conservative treatment group.

Clinical significance: OCD lesions within the femoropatellar joint in Standardbred racehorses resulted in minimal impact on postoperative racing performance when removed arthroscopically.

Objective: The aim of this retrospective study was to investigate the relative frequency of R0 margin classification following excision of canine apocrine gland anal sac adenocarcinoma (AGASACA). Secondary aims were to establish if R0/R1 margins, or other dog or tumor characteristics, were prognostic.

Study design: Retrospective cohort study.

Sample population: Seventy-four dogs that underwent AGASACA excision.

Methods: Each tumor margin was classified as R0 or R1 from the histopathology report. Additional data relating to primary tumor characteristics, preoperative assessment, local recurrence, metastases and survival were collated from the medical record.

Results: The rate of R0 margin classification following AGASACA excision was 75.7%. An R1 margin classification was associated with increased risk of local recurrence (OR 23, p < .0001). Overall median survival time following surgery was 25 months (95% CI 21-33). Survival time was reduced in dogs with preoperative hypercalcemia (7.5 months, p = .012), presence of metastatic disease (17 months, p = .005) and lymphovascular invasion on histopathology (21 months, p = .021). Mitotic count (p = .0069) and absence of adjunct therapy (p = .0247) also reduced survival time.

Conclusion: The R margin classification was clinically useful in predicting local recurrence. Preoperative hypercalcemia, lymphovascular invasion on histopathology, presence of metastatic disease, mitotic count, and absence of adjunct therapy all negatively affected survival.

Clinical impact: Achieving complete margins was feasible in most dogs undergoing AGASACA excision and reduced the risk of local recurrence. The R margin classification scheme was clinically useful when reporting histopathology of canine AGASACAs.

Objective: To increase awareness of black thyroid in dogs and to prevent unnecessary total thyroidectomy. A benign condition called "black thyroid" has been documented in greater than 250 people on chronic minocycline therapy, and rarely in animals. To our knowledge this is the first report of black thyroid in an animal secondary to doxycycline therapy.

Study design: Case report.

Animal: One 10 year-old female spayed Collie-cross dog.

Methods: A dog on long-term doxycycline underwent a right parotid sialoadenectomy and left thyroidectomy to remove associated tumors. Black pigmentation of both thyroid lobes was observed intraoperatively. The left thyroid gland and associated nodule were excised, leaving the right lobe intact.

Results: Histopathology of the left thyroid nodule and right parotid salivary gland were consistent with thyroid follicular-compact cell carcinoma with metastasis. Finely granular brown pigment was present multifocally within the cytoplasm of many of the thyroid follicular cells and extracellularly within the colloid as irregular gray to brown glassy aggregates. The pigment was negative for iron and calcium and had minimal to no immunoreactivity for melanin.

Conclusion: These findings aligned with those reported for the condition black thyroid in humans. At this time, there is no evidence that performing a thyroidectomy is necessary or appropriate for black thyroid. Veterinary surgeons should be aware that dogs on long-term doxycycline therapy may have this discoloration, so unnecessary total thyroidectomy can be prevented in affected animals.