Fluoroscopic Categorization of Cementless Acetabular Component Positioning.

OBJECTIVES: The purpose of this study was to evaluate a fluoroscopic method of angle of lateral opening (ALO) categorization based on identification of the visible portion of a pre-existing, circular recess within the metal shell of the BioMedtrix BFX acetabular component, which projects as an ellipse at clinically relevant ALO values. Our hypothesis was that there will be an association between the actual ALO and the categorization of ALO based on identification of the visible portion of the elliptical recess on a lateral fluoroscopic image at clinically relevant values. STUDY DESIGN: A custom plexiglass jig was fitted with a two-axis inclinometer and a 24 mm BFX acetabular component attached to its tabletop. Fluoroscopic reference images were obtained with the cup positioned at an ALO of 35, 45 and 55 degrees with a fixed 10 degrees of retroversion. Thirty study fluoroscopic images (10 images at each ALO) were obtained based on randomization at an ALO of 35, 45 and 55 degrees (±0.5 degrees) with 10 degrees of retroversion. The order of the study images was randomized, and a single, blinded observer categorized the 30 study images as representing an ALO of 35, 45 or 55 degrees by comparison to the reference images. RESULTS: Analysis showed perfect (30/30) agreement with a weighted kappa coefficient of 1 (95% confidence interval: -0.717 to 1). CLINICAL RELEVANCE: The results demonstrate that accurate categorization of ALO can be achieved using this fluoroscopic method. This method may prove to be a simple but effective method of estimating intraoperative ALO.

Conservative nonsurgical treatment for cranial cruciate ligament disease can be an effective management strategy in cats based on validated owner-based subjective assessment in some cases.

OBJECTIVE: To describe long-term outcomes of cats managed medically for cranial cruciate ligament disease (CCLD) via a validated owner-based questionnaire. ANIMALS: 18 client-owned cats. PROCEDURES: Retrospective review of medical records at 2 tertiary referral hospitals was conducted for records of cats diagnosed with CCLD for which medical management was pursued. History, physical examination findings, and medical management strategies were recorded. Owner follow-up was obtained via phone call or an email correspondence interview using a 2-part questionnaire. Part 1 consisted of 5 multiple-choice questions evaluating short-term outcomes following initiation of medical management. Part 2 assessed long-term outcomes via the validated Feline Musculoskeletal Pain Index-short form metrology instrument. RESULTS: Mean follow-up time was 66.5 ± 46.7 months (range, 7 to 154 months). Medical management included oral analgesics, activity restriction, and joint supplements. Of the 18 cats, 13 (72%) were always able to bear weight or became weight bearing within a week following initiation of medical management, and 15 (83%) were reportedly clinically normal within 3 months of initiating medical management, with complete resolution of lameness occurring in less than 2 months in 12 of those cats. Long term, 17 of the 18 (94%) owners reported they felt that their cat had a good to excellent outcome with medical management. The mean Feline Musculoskeletal Pain Index-short form score of all cats was 0.29 ± 0.53 (range, 0 to 2.13). CLINICAL RELEVANCE: Based on owner follow-up, conservative, nonsurgical management of CCLD can be an effective and appropriate management strategy for some cats; however, some may be best treated with surgical stabilization.

Measurement of Acetabular Component Position in Total Hip Arthroplasty in Dogs: Comparison of a Radio-Opaque Cup Position Assessment Device Using Fluoroscopy with CT Assessment and Direct Measurement.

OBJECTIVES: The aim of this study was to compare measurements of angle of lateral opening (ALO) and version determined using a radioopaque cup position assessment device imaged with fluoroscopy to measurements obtained by CT and direct measurement in a cadaveric model. Our null hypothesis was that there would not be any difference in the angles measured by the techniques. METHODS: Six cadavers were implanted with BFX acetabular components. The CPAD was placed and images were obtained with fluoroscopy. Measurements were obtained from the radiopaque marker bars on the CPAD device, and version and ALO were calculated. The ALO and version were determined by CT and DM. Comparisons were made using a two-way analysis of variance and a generalized linear model procedure analysis. RESULTS: There were no significant differences between the measurements for ALO (p = 0.275) or version (p = 0.226). Correlation between methods was 0.948 and 0.951 for ALO and version, respectively. The mean difference (standard deviation [SD], and 95% confidence interval [CI]) for ALO were: CT versus CPAD 1.85 degrees (± 2.32 degrees [-2.99-3.31]), CT versus DM 1.96 degrees (± 1.99 degrees [-2.2-4.27]), CPAD versus DM1.74 degrees (±2.21 degrees [-1.13 and 5.24]). The mean difference (SD [CI]) for version was CT versus CPAD 2.86 degrees (±1.56 degrees [ -2.63-1.69]), CT versus DM 1.10 degrees (±1.42 degrees [-1.57-2.09]), CPAD versus DM 1.07 degrees (±0.76 degrees [0.13-2.09]). CLINICAL RELEVANCE: The results demonstrate that intraoperative imaging in cadaveric specimens with the CPAD is an accurate method to determine ALO and version of the acetabular component.

Evaluation of experimentally induced injury to the superficial digital flexor tendon in horses by use of low-field magnetic resonance imaging and ultrasonography.

OBJECTIVE: To evaluate tendon injuries in horses over a 16-week period by use of ultrasonography and low-field magnetic resonance imaging (MRI). SAMPLE: Tendons of 8 young adult horses. PROCEDURES: The percentage of experimentally induced tendon injury was evaluated in cross section at the maximal area of injury by use of ultrasonography and MRI at 3, 4, 6, 8, and 16 weeks after collagenase injection. The MRI signal intensities and histologic characteristics of each tendon were determined at the same time points. RESULTS: At 4 weeks after collagenase injection, the area of maximal injury assessed on cross section was similar between ultrasonography and MRI. In lesions of > 4 weeks' duration, ultrasonography underestimated the area of maximal cross-sectional injury by approximately 18%, compared with results for MRI. Signal intensity of lesions on T1-weighted images was the most hyperintense of all the sequences, lesions on short tau inversion recovery images were slightly less hyperintense, and T2-weighted images were the most hypointense. Signal intensity of tendon lesions was significantly higher than the signal intensity for the unaltered deep digital flexor tendon. Histologically, there was a decrease in proteoglycan content, an increase in collagen content, and minimal change in fiber alignment during the 16 weeks of the study. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonography may underestimate the extent of tendon damage in tendons with long-term injury. Low-field MRI provided a more sensitive technique for evaluation of tendon injury and should be considered in horses with tendinitis of > 4 weeks' duration.

Surgical repair of a cleft palate in an American bison (Bison bison).

A 4-mo-old bison (Bison bison) was evaluated and treated at a university veterinary hospital for a cleft defect in the hard and soft palate. Using a mandibular symphysiotomy approach, the palatal defect was repaired with a Z-plasty pattern in the soft palate and mucoperiosteal flaps in the hard palate. A small area of dehiscence in the rostral aspect of the hard palate, and aspiration pneumonia, were complications, but the bison calf recovered with medical management. Even though this surgical procedure has a high potential for complications, the described technique allowed return to normal feeding and resolution of the aspiration pneumonia by 14 mo postsurgery.

Modified tenoscopic method for carpal flexor retinaculum release in a horse.

OBJECTIVE: To report the use of a proximolateral endoscopic portal with a distolateral instrument portal for carpal retinaculum release in a horse clinically affected with carpal canal syndrome. STUDY DESIGN: Clinical report. ANIMALS: A 4-year-old Thoroughbred female. METHODS: Carpal canal syndrome secondary to traumatic suppurative tenosynovitis was treated by accessory carpal bone debridement and carpal retinaculum release using a tenoscopic approach to the carpal flexor synovial sheath through a proximolateral endoscope portal and a distolateral instrument portal. RESULTS: Resolution of carpal sheath effusion and lameness occurred allowing racing 14 months later. Use of a distolateral instrument portal was not associated with complications or iatrogenic damage to neurovascular structures and reduced endoscope and instrument interference and offered easier access to the distal aspect of the carpal sheath. CONCLUSIONS: Carpal retinaculum release may be safely accomplished with a distolateral instrument portal when access to the distal aspect of the carpal sheath is needed. CLINICAL RELEVANCE: The distolateral instrument portal described may be a useful alternative to a proximolateral portal when distal carpal sheath instrument access is necessary or advantageous.