Long-term follow up of 44 cats undergoing total hip replacement: Cases from a feline hip registry (2010-2020).

OBJECTIVE: To report indications, complications, and long-term outcomes following feline total hip replacement (THR) using a client-based clinical metrology questionnaire, the Feline Musculoskeletal Pain Index (FMPI), and owner satisfaction. STUDY DESIGN: Multi-institutional retrospective cohort study. ANIMALS: Cats (n = 44) that underwent THR (n = 56). METHODS: Feline THRs submitted to a registry over a 10-year period were reviewed. The FMPI and owner satisfaction surveys were used to assess outcome. RESULTS: Forty-four cats met the inclusion criteria. Median age was 2 years (range: 0.9-11), and median bodyweight 5 kg (range: 3.3-7.6). British Shorthair and Domestic Shorthair were the most frequent breeds. Most cats were neutered males (33/44) and slipped capital femoral epiphysis (SCFE) was the most common surgical indication (34/56). All implants were cemented micro and nano hip implants. Overall complications (11/56) included 9 major complications. The median duration of follow up was 752 days (range: 102-3089). No association was found between clinical variables and complications. The FMPI score improved from 0.111 (range: 0-1.222) to 2.111 (range: 0.888-3.666) postoperatively (P < .001). Owner satisfaction was reported as "very good" in 30/33 cases (90.9%). CONCLUSION: A validated client metrology questionnaire showed clinical improvement in cats following THR. The most common indication for THR in cats was SCFE occurring in young male neutered cats. Complication rates were comparable to previous reports. CLINICAL SIGNIFICANCE: Total hip replacement appears to be a successful surgical treatment for feline hip disease with very good owner satisfaction and acceptable complication rates.

Repair of Fractures of the Lateral Aspect of the Humeral Condyle in Skeletally Mature Dogs with Locking and Non-Locking Plates.

OBJECTIVE: The aim of this study was to report the functional outcome and complications following transcondylar screw and epicondylar plate fixation of skeletally mature dogs with fractures of the lateral aspect of the humeral condyle using a string of pearls, limited contact dynamic compression plate (LC-DCP) or locking compression plate (LCP). STUDY DESIGN: This study was a retrospective review of clinical records, radiographic images and canine brief pain inventory evaluation with a supplementary non-validated questionnaire. RESULTS: Thirty-one fractures in 29 dogs were included. The majority of dogs were Spaniels (23/29). Thirty fractures had evidence of humeral intracondylar fissure. Sixteen fractures had string of pearls, eight LCP and seven LC-DCP. There were two minor complications and three major complications. Perioperative (median: 6 weeks, range: 6-12) outcome was considered fully functional for 24 fractures and acceptable for 6 fractures. One dog had an unacceptable outcome due to the failure of an LCP that healed following revision surgery. Fractures with radiographic follow-up had a persistent visible intracondylar fracture line in 20/26. Twenty-six of twenty-seven owners perceived an excellent outcome (median: 135 weeks, range: 25-246). CONCLUSION: Repair of fractures of the lateral aspect of the humeral condyle with a transcondylar screw and epicondylar plate has a good perioperative, mid- and long-term outcome with 10% major complication rate, despite incomplete or non-union of the intracondylar fracture in 20/26 elbows.

Single Transsacral Screw and Nut Stabilization of Bilateral Sacroiliac Luxation in 20 Cats.

OBJECTIVE: This article aims to describe the use of a single transsacral screw and nut in a cohort of cats with bilateral sacroiliac (SI) luxation and document its radiographic and clinical outcome. METHODS: Medical records and radiographic studies of cats with bilateral SI luxation managed with a transsacral screw and nut stabilization were reviewed. Short-term follow-up included clinical examination and radiographs. Long-term follow-up was via owner questionnaire. RESULTS: Twenty consecutive cats with bilateral SI luxation were included. Six cats (35%) had additional musculoskeletal injuries that required stabilization. Luxations were stabilized with a single 2.7 cortical self-tapping transsacral screw and nylon nut (a metallic nut was used in one case). Postoperative radiographs confirmed SI reduction in all cats and a mean pelvic canal width ratio of 1.21 (a ratio of ≥1.1 was considered optimal). All cats available at follow-up examination were able to walk without signs of discomfort. Evaluation of follow-up radiographs showed maintenance of SI reduction and slight reduction of mean pelvic canal width ratio (1.18). Fourteen owner questionnaires were returned (median follow-up time of 40 months): nine cats were deemed to have normal activity and five cats were reported to have slight to mild reduced ability to jump or run. CLINICAL SIGNIFICANCE: The use of transsacral screw and nut stabilization of bilateral SI luxation in cats is a successful, repeatable and safe technique.

Efficacy of Postoperative Antimicrobial Use for Clean Orthopedic Implant Surgery in Dogs: A Prospective Randomized Study in 100 Consecutive Cases.

OBJECTIVES: To investigate whether administration of postoperative oral antimicrobial drugs has a beneficial effect on preventing surgical site infections (SSI) in clean orthopedic surgery involving stainless steel plating systems. STUDY DESIGN: Randomized prospective clinical study. ANIMALS: Dogs (n = 97). METHODS: One hundred consecutive cases (97 dogs) that had clean orthopedic surgery requiring stainless steel plate fixation were randomly assigned using a random number generator to either YES group (administration of postoperative oral antimicrobials) or NO group (no administration of postoperative oral antimicrobials). Dogs in YES group were administered oral cefalexin or potentiated amoxicillin for 7 days, whereas dogs in NO group were discharged without oral antibiotics. Minimum follow-up was 12 months. Multivariable logistic regression was used to determine risk factors for SSI. RESULTS: Overall postoperative infection rate was 12.9%. Infection occurred in 2 cases (4.3%) administered postoperative oral antimicrobials and in 10 cases (21.3%) not administered postoperative antimicrobials. Total anesthetic time and use of oral antimicrobials were the only significant factors associated with SSI. Use of postoperative antimicrobials was associated with a significant reduction in the risk of infection by ~84% and risk of infection was increased by ~2% for each minute increase in anesthesia time. CONCLUSIONS: Administration of oral postoperative antimicrobials had a protective effect against development of SSI in clean orthopedic implant surgery.

In vitro comparison of mechanical and degradation properties of equivalent absorbable suture materials from two different manufacturers.

OBJECTIVE: To compare the mechanical, knotting, and absorption properties of 3 synthetic absorbable suture materials (polyglactin 910, polydioxanone, poliglecaprone 25) from 2 different manufacturers (Huaiyin Medical Instruments Co. Ltd. and Ethicon Inc.). SAMPLE POPULATION: Suture material samples from the same manufacturing lot for each suture type and manufacturer. METHODS: Part 1: 10 samples of each suture were incubated in bovine serum and tested for ultimate load and stiffness at days 0, 1, 7, 14, 21, and 28. Part 2: 10 knotted samples were similarly evaluated, without incubation. RESULTS: Huaiyin polydioxanone had a greater (P<.001) ultimate load on days 0, 1, and 7; and a consistently greater stiffness for the duration of the study, compared with the Ethicon polydioxanone. Ethicon poliglecaprone 25 had a greater ultimate load on days 0, 1, 7 (P<.001); on day 21 Huaiyin had a greater ultimate load. Ethicon poliglecaprone had greater stiffness on days 0, 1, 7 (P<.001). Ethicon polyglactin 910 had a greater (P<.001) ultimate load at all times and a greater stiffness (P<.001) at days 0, 1, 7, and 14 compared with Huaiyin polyglactin 910. Huaiyin polydioxanone and polyglactin 910 had greater knot breaking strengths than Ethicon equivalents (P<.001). CONCLUSION: Differences in mechanical properties exist between nominally identical suture materials from different manufacturers.

Improved detection of CXCR4-using HIV by V3 genotyping: application of population-based and "deep" sequencing to plasma RNA and proviral DNA.

BACKGROUND: Tropism testing should rule out CXCR4-using HIV before treatment with CCR5 antagonists. Currently, the recombinant phenotypic Trofile assay (Monogram) is most widely utilized; however, genotypic tests may represent alternative methods. METHODS: Independent triplicate amplifications of the HIV gp120 V3 region were made from either plasma HIV RNA or proviral DNA. These underwent standard, population-based sequencing with an ABI3730 (RNA n = 63; DNA n = 40), or "deep" sequencing with a Roche/454 Genome Sequencer-FLX (RNA n = 12; DNA n = 12). Position-specific scoring matrices (PSSMX4/R5) (-6.96 cutoff) and geno2pheno[coreceptor] (5% false-positive rate) inferred tropism from V3 sequence. These methods were then independently validated with a separate, blinded dataset (n = 278) of screening samples from the maraviroc MOTIVATE trials. RESULTS: Standard sequencing of HIV RNA with PSSM yielded 69% sensitivity and 91% specificity, relative to Trofile. The validation dataset gave 75% sensitivity and 83% specificity. Proviral DNA plus PSSM gave 77% sensitivity and 71% specificity. "Deep" sequencing of HIV RNA detected >2% inferred-CXCR4-using virus in 8/8 samples called non-R5 by Trofile, and <2% in 4/4 samples called R5. CONCLUSIONS: Triplicate analyses of V3 standard sequence data detect greater proportions of CXCR4-using samples than previously achieved. Sequencing proviral DNA and "deep" V3 sequencing may also be useful tools for assessing tropism.

Computed tomography versus arthroscopy for detection of canine elbow dysplasia lesions.

OBJECTIVE: To describe associations between computed tomography (CT) and arthroscopy in dogs with elbow dysplasia lesions. STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: Canine elbows (n=101) investigated by CT and arthroscopy. METHODS: CT scans were reviewed for 10 predetermined CT signs and graded for osteophyte size. Surgical reports were reviewed for specific disease features and cartilage erosion grades. Associations between variables were investigated with multivariate logistic regression and correlation between osteophyte size and cartilage erosion with Spearman's rank order correlation. RESULTS: Medial coronoid process (MCP) fragment on CT was significantly associated with the arthroscopic identification of a displaced MCP fragment, cartilage erosion affecting the MCP, and cartilage erosion affecting the humeral condyle. Irregular radial incisure of the ulna on CT was significantly associated with the arthroscopic identification of cartilage erosion affecting the MCP. Osteophytes on CT were significantly associated with an abnormal arthroscopic examination. There was a moderately significant correlation between CT osteophyte grade and cartilage erosion grades for areas of the medial joint compartment (r(s)=0.44-0.48). CONCLUSION: Some CT signs are significantly associated with arthroscopic features of elbow dysplasia lesions in dogs; however, other CT signs were not associated with arthroscopic findings, and CT and arthroscopy can provide contradictory information. Osteophyte size is moderately correlated with cartilage erosion of the medial joint compartment. CLINICAL RELEVANCE: CT can provide valuable information for the investigation of dogs with elbow dysplasia, but the absence of CT signs (or the absence of arthroscopic abnormalities) does not rule out elbow lesions.

Factors affecting width of the canine femorotibial joint space in nonweight-bearing radiographs.

Caudocranial stifle radiographs with variations in positioning were made in two greyhound cadavers. Radiographs were repeated after each of three interventions: cranial cruciate desmotomy; release of the caudal horn of the medial meniscus; complete medial meniscectomy. The joint space on medial and lateral aspects of the joint was measured by a observer who was unaware of positioning or intervention. One dog had significantly wider joint space than the other (1.0 vs. 1.5mm). The lateral aspect of the joint space was wider than the medial aspect (1.7 vs. 0.7 mm). Medial rotation of the stifle resulted in an increase of 0.4 mm in width of the lateral joint space, whereas lateral rotation of the stifle reduced the lateral joint space by an average of 0.4 mm. Decentering the X-ray beam had no significant effect on joint space width. Tension increased the width of the medial joint space by an average of 1.2 mm and the lateral aspect by an average of 1.3 mm. Cranial cruciate desmotomy resulted in an average 0.3 mm increase in width of the joint space, and medial meniscectomy with an average 0.2 mm reduction of the joint space. Although the femorotibial joint space was affected by iatrogenic stifle injuries and by medial or lateral rotation, these changes were less than the differences between the two dogs. Hence it seems unlikely that the small changes in joint space width associated with cruciate ligament desmotomy and medial meniscectomy will be detectable in clinical practice.

Regional load bearing of the canine acetabulum.

OBJECTIVE: To determine the load bearing areas of the canine acetabulum. MATERIALS AND METHODS: A kinematic study of four healthy dogs was used to determine the orientation of the femur to the pelvis at mid-stance. Femora and pelves from 10 canine cadavers were loaded with the physiological canine hip reaction force and angle being replicated. Impression material placed within the acetabulum was extruded from areas of load bearing. Digital images before and after loading were used to assess if six different regions of the acetabulum were fully, partially or non-load bearing. RESULTS: All areas of the acetabulum were partially or fully load bearing. The cranial and caudal thirds of the acetabulum were 7.9 and 13.1 times more likely to be fully load bearing than the central third, respectively. There was a significant difference in load bearing between the axial, middle and abaxial thirds of the acetabulum in all tests, with the middle and abaxial thirds 72.4 and 351 times more likely to be fully load bearing than the axial third, respectively. CONCLUSION: The cranial and caudal thirds and the middle and abaxial thirds of the canine acetabulum are fully load bearing. CLINICAL RELEVANCE: The caudal third of the canine acetabulum is loaded and therefore recommendations that fractures in this area be managed conservatively need to be reconsidered.

Mechanical evaluation of two crimp clamp systems for extracapsular stabilization of the cranial cruciate ligament-deficient canine stifle.

OBJECTIVE: To compare the mechanical properties and interoperator variabilities of 2 crimp clamp systems for extracapsular, fabello-tibial, nylon loop stabilization of the cranial cruciate ligament-deficient stifle in dogs. STUDY DESIGN: In vitro mechanical testing. METHODS: Three operators with different grip strengths each secured 20 standardized nylon loops using stainless-steel crimp clamps: 10 using a Veterinary Instrumentation system (45 kg [100 lb] test nylon leader line, 12 mm crimp clamps) and 10 using a Securos system (36 kg [80 lb] test nylon leader line, 36 kg [80 lb] crimp clamps). Loops were tensile loaded to failure in a materials testing machine. RESULTS: Mean ultimate load and mean stiffness were significantly higher for the Securos (336.9 N, 60.6 N/mm) than for the Veterinary Instrumentation system (113.8 N, 37.0 N/mm). For both systems, ultimate load was subject to interoperator variability. CONCLUSIONS: The Securos loops were significantly stronger and stiffer than the Veterinary Instrumentation loops for all operators, but significant differences between operators for ultimate load existed for both systems. CLINICAL RELEVANCE: Securos fabello-tibial sutures will withstand greater loads than Veterinary Instrumentation sutures and this is particularly true for sutures created by surgeons with reduced grip strength. It may be necessary to use more than 1 Veterinary Instrumentation suture to match the ultimate load and stiffness of a Securos suture.

Mechanical evaluation of two loop tensioning methods for crimp clamp extracapsular stabilization of the cranial cruciate ligament-deficient canine stifle.

OBJECTIVES: To describe a method of tightening nylon loops secured with a crimping system for extracapsular fabello-tibial stabilization of the cranial cruciate ligament-deficient stifle and to compare this with a method using a commercially available tensioning device. STUDY DESIGN: In vitro mechanical testing. METHODS: Fourteen standardized nylon loops were tensioned using a tensioning device and secured with crimp clamps. Another 14 loops were tightened by partially securing the crimp clamp, followed by tightening of the loop by hand, before definitively securing the crimp clamp. Loops were loaded to failure in a materials testing machine. RESULTS: Mean ultimate loads for instrument-tightened and hand-tightened loops were 383.7 and 371.4 N, respectively. Mean stiffness values for instrument-tightened and hand-tightened loops were 59.7 and 59.3 N/mm, respectively. These differences were not significant. CONCLUSIONS: The hand tightening method does not affect the mechanical properties of the loop. CLINICAL RELEVANCE: The hand tightening method described is a valuable technique for unassisted surgeons without access to tensioning devices.