Veterinary Surgery最新文献

Objective: To describe a novel dorsal occipito-cervical fixation technique utilizing a patient-specific implant to stabilize complex craniocervical junction anomalies (CCJAs) in a small-breed dog.

Study design: Case report.

Animal: A 7-month-old male Pomeranian dog.

Methods: The dog presented with ambulatory tetraparesis and cervical pain. Advanced imaging revealed fusion of the C2-C4 vertebrae, occipital condyle hypoplasia, and atlas ventral arch hypoplasia, resulting in atlanto-occipital dislocation and atlantoaxial instability. A patient-specific dorsal occipito-cervical implant and implant-specific drill guide were designed from computed tomography (CT)-based three-dimensional models to incorporate predefined geometric constraints and planned screw trajectories, enabling controlled intraoperative realignment and dorsal stabilization.

Results: Postoperative CT confirmed satisfactory alignment with no evidence of implant migration. Neurologic function improved gradually, with ambulation achieved by two months, and stability was maintained through 33 months of follow-up.

Conclusion: This case demonstrated the feasibility of patient-specific dorsal occipito-cervical fixation in a small-breed dog with complex CCJAs.

Objective: To determine the prevalence of ununited plantar eminence (UPE) of the first phalanx (P1) in North American Standardbreds and evaluate its association with early racing performance.

Study design: Retrospective cohort study with matched sibling controls.

Sample population: Imaging records from 1897 yearling Standardbred horses.

Methods: Screening images were reviewed for the presence of UPE and other orthopedic abnormalities. Sex, age, sire, gait, and racing performance data were obtained from the United States Trotting Association. Affected horses were compared with unaffected siblings using non-parametric tests for performance outcomes. Within affected horses, regression analyses were used to assess the influence of sex, gait, and concurrent developmental orthopedic disease (DOD) lesions on performance.

Results: UPE was identified in 74 of 1898 horses (3.9%). Most affected horses (67.6%) had concurrent DOD lesions, most commonly plantar osteochondral fragments. At two years of age, there were no differences in performance outcomes between groups. As 3-year-olds, affected horses were less likely to start, and had fewer starts and lower earnings than unaffected siblings.

Conclusion: UPE of P1 was an uncommon finding frequently associated with other DOD lesions. While 2-year-old racing performance was similar between groups, affected horses showed reduced performance during the three-year-old season.

Clinical significance: UPE could have meaningful implications for long-term athleticism in Standardbred racehorses, given the reduced racing performance at 3 years of age in the affected study cohort. However, as UPE is frequently found in combination with other DOD lesions, the clinical relevance of UPE as an isolated lesion is not clear.

Objective: To compare short- and long-term clinical variables in cats undergoing a modified percutaneous cystolithotomy (PCCLm) or open cystotomy (OC) and to identify risk factors associated with complications and outcomes within the groups.

Study design: Retrospective study.

Animals: Fifty-two client-owned cats.

Methods: Records were reviewed for cats that underwent PCCLm or OC between December 2010 and August 2023. Signalment, history, diagnostic findings, procedural and anesthetic details, hospitalization data, complications, urolith recurrence, and follow up were recorded. χ² or Fisher's exact tests and two-sample t-tests were used to evaluate effects of categorical and numerical clinical variables respectively on outcomes within PCCLm and OC groups and between PCCLm and OC groups.

Results: A total of 54 procedures were performed, 19 PCCLm (36.5%) and 35 OC (65.5%). Hospitalization duration (p = .031) and incision length (p = .002) were greater in the OC group. Incisional infections were associated with hospitalization duration in the OC group (p = .048). Incomplete urolith removal was associated with increased surgical time (p = .039) when no additional procedures were performed in the OC group. For PCCLm, incomplete urolith removal was associated with lower urinary tract signs within 14 days postoperatively (p = .018), increased incision length (p = .029), anesthesia time (p = .017), and hospitalization duration (p = .027).

Conclusion: Modified percutaneous cystolithotomy resulted in shorter incisions and hospitalization duration postoperatively in comparison with OC but no other clear advantages of PCCLm were identified.

Clinical significance: The PCCLm procedure is an acceptable alternative to OC for urolith removal in cats.

Objective: To describe a novel, coaptationless surgical technique for the treatment of multiligament stifle injuries (MLSI).

Study design: Retrospective case series.

Animals: A total of 23 cats presenting with a rupture of two or more ligaments stabilizing the stifle.

Methods: Specific surgical techniques were used to reconstruct each deficient ligament. The TightRope procedure was utilized to treat the cranial cruciate ligament and the lateral collateral ligament injuries. Intra-articular reconstruction was adopted for the caudal cruciate ligament. The medial collateral ligament was reconstructed using knotless anchors. Postoperative joint immobilization was not employed in any case. Clinical evaluations were performed up to 6 months postoperatively including the feline musculoskeletal pain index (FMPI).

Results: Initial stabilization of MLSI using the described techniques was achieved in all cases. Major complications occurred in six cases: four involved recurrent caudal cruciate ligament instability, and two involved medial patellar luxation. All complications were resolved with revision surgery, except in one case where arthrodesis was required. At follow-up evaluations, lameness ranged from grade 1 to undetectable. FMPI scores ranged from 0.95 to 1.0.

Conclusion: The surgical technique described offers an effective approach for managing MLSI in cats without the need for temporary immobilization, provided that all injured ligaments are appropriately reconstructed. Specifically, reconstruction of the caudal cruciate ligament should be performed when deficient, as it may help mitigate the risk of postoperative complications.

Clinical significance: This coaptationless technique allows for effective restoration of stifle stability in feline patients, with low complication rates and good clinical outcomes.

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 quantify how increasing axial loads, femoral fixation methods (rigid vs. flexion-extension mobility) and joint angles reflecting early versus mid-stance impact simulated quadriceps and gastrocnemius forces.

Study design: Non-randomized, cadaveric experimental study.

Sample population: Unpaired canine pelvic limbs (n = 10) from adult large-breed dogs.

Methods: Limbs were mounted in a custom limb press with the femur sequentially rigidly fixed at 70° to horizontal or allowed flexion-extension. Quadriceps and gastrocnemius muscles were simulated with load cells and turnbuckles. Axial loads of 10%, 20% and 30% bodyweight (BW) were applied. Stifle and hock angles were sequentially fixed to represent mid- (135° and 145°) or early stance (145° and 135°). Outcome measures were BW normalized simulated muscle loads and their ratio. Data were analyzed using non-parametric repeated measures.

Results: Quadriceps and gastrocnemius forces increased with axial load (p < .001). Quadriceps force was unaffected by fixation method but showed higher mid-stance values in flexion-extension models at 20% and 30% loads (p = .03). Gastrocnemius force varied by configuration (p = .01) and showed significant load-configuration interactions (p = .003); mid-stance values were lower than early stance in flexion-extension models. Muscle force ratios were consistent across loads (p = .2) but differed by configuration (p = .02), with higher mid-stance values in flexion-extension models.

Conclusion: Femoral fixation method and stance configuration had limited impact on simulated muscle forces. Flexion-extension mobility did not substantially increase muscle loading.

Impact: Rigid femoral fixation remains a valid approach for canine limb press models.

Objective: To describe postoperative subsidence observed after total hip replacement (THR) with the BFX standard stem.

Study design: Retrospective case series.

Sample population: A total of 177 THR procedures in 145 dogs.

Methods: Clinical and radiographic follow-up data were collected between 12 weeks and six months postoperatively. A proportion correction was used to calculate subsidence between immediate postoperative and follow-up radiographs. Canal flare index, coronal canal fill, sagittal canal fill, coronal stem orientation and sagittal stem orientation were measured.

Results: There were 24/177 (13.6%) intra- and postoperative complications. Of these, 11/177 (6.2%) were stem complications. Eight stem complications were intraoperative femoral fissures; one fissure progressed to postoperative femoral fracture. Subsidence was associated with stem complications (p = .005) and was not associated with non-stem complications (p = .76) or prosthetic luxation (p = .07). There were seven stems with more than 5.0 mm of subsidence; of these only 1/7 had a stem complication. There were 26 stems with more than 3.0 mm of subsidence; of these only 3/26 had a stem complication. There was no association between any femoral or stem measurements and subsidence.

Conclusion: Subsidence of the BFX standard stem was associated with stem complications, which were mostly intraoperative femoral fissures. Thresholds of 3.0 and 5.0 mm were poorly predictive of complications, and substantial subsidence was often clinically inconsequential.

Clinical significance: Cutoffs for excessive subsidence may have limited clinical utility. The significance of postoperative subsidence should be interpreted in the context of other clinical findings.

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: 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 determine the natural progression of tarsal osteochondrosis (OC) in a cohort of Standardbred foals and assess the impact of gait preference (trotting vs. pacing).

Study design: Longitudinal observational cohort study.

Animals: Client-owned Standardbred foals (n = 148).

Methods: Tarsal radiographs were taken every 2 months from 2 to 12 months of age and foals were video monitored to document time spent pacing or trotting. Differences between groups were assessed using χ² analysis. Survival analysis was used to determine if lesion healing differed between groups over time.

Results: Of 148 horses, 103 (69.6%) had OC lesions at 2 months of age but only 32 (21.6%) still had OC lesions by 12 months. In 28 of these horses, the lesions had progressed to osteochondrosis dissecans (OCD). Of 71 horses with lesions that healed, 60 (84.5%) did so by 6 months of age. Gait was not associated with presence or absence of OC lesions or healing of lesions over time. Foals spent less than 1% of their observed time trotting or pacing.

Conclusion: Tarsal OC lesions were prevalent in this cohort of young Standardbreds, and most lesions healed within the first few months of life. There was no evidence for direct biomechanical forces from movement at the pace or trot affecting the location of OCD fragment development.

Clinical significance: The critical window for tarsal OC lesion healing was prior to 6 months of age and further investigation of risk factors present during this time frame is warranted.