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- Author or Editor: Scott A. Christopher x
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OBJECTIVE To compare the effects of 3 equimolar concentrations of methylprednisolone acetate (MPA), triamcinolone acetonide (TA), and isoflupredone acetate (IPA) on equine articular tissue cocultures in an inflammatory environment.
SAMPLE Synovial and osteochondral explants from the femoropatellar joints of 6 equine cadavers (age, 2 to 11 years) without evidence of musculoskeletal disease.
PROCEDURES From each cadaver, synovial and osteochondral explants were harvested from 1 femoropatellar joint to create cocultures. Cocultures were incubated for 96 hours with (positive control) or without (negative control) interleukin (IL)-1β (10 ng/mL) or with IL-1β and MPA, TA, or IPA at a concentration of 10−4, 10−7, or 10−10M. Culture medium samples were collected from each coculture after 48 and 96 hours of incubation. Concentrations of prostaglandin E2, matrix metalloproteinase-13, lactate dehydrogenase, and glycosaminoglycan were determined and compared among treatments at each time.
RESULTS In general, low concentrations (10−7 and 10−10M) of MPA, TA, and IPA mitigated the inflammatory and catabolic (as determined by prostaglandin E2 and matrix metalloproteinase-13 quantification, respectively) effects of IL-1β in cocultures to a greater extent than the high (10−4M) concentration. Mean culture medium lactate dehydrogenase concentration for the 10−4M IPA treatment was significantly greater than that for the positive control at both times, which was suggestive of cytotoxicosis. Mean culture medium glycosaminoglycan concentration did not differ significantly.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the in vitro effects of IPA and MPA were similar to those of TA at clinically relevant concentrations (10−7 and 10−10M).
OBJECTIVE To determine short- and long-term outcomes and complications of dogs undergoing surgical correction of grade IV medial patellar luxation (MPL).
DESIGN Retrospective case series.
ANIMALS 24 dogs (29 stifle joints) that underwent surgical correction of grade IV MPL between March 2008 and April 2014.
PROCEDURES Medical records of all dogs were reviewed. When available, long-term follow-up information was obtained for each dog via the orthopedic surgeon (results of orthopedic examination and radiographic interpretation) and the dog's owner (responses to a questionnaire regarding postsurgical outcomes). Types of postsurgical complications and intervals to follow-up data collection were recorded. Recurrence of MPL was recorded separately. Successful outcome was defined as one without catastrophic complication, with owner-reported full or acceptable return to function and a surgeon- and owner-assigned pain or lameness score < 3.
RESULTS 24% (7/29) of stifle joints had major complications, and 21% (6) of joints required surgical revision. Grade II to IV recurrence of MPL was identified in 21% (6) of stifle joints. One dog had a catastrophic complication requiring limb amputation. For all other dogs, owner-reported return to function was full or acceptable. Surgeon-assigned pain and lameness scores for all dogs at the final follow-up evaluation were < 2/5 (0 = pain or lameness free). Surgical correction of grade IV MPL had an overall success rate of 93% (27/29).
CONCLUSIONS AND CLINICAL RELEVANCE Surgical correction of grade IV MPL in dogs had a favorable overall success rate; however, owners should be counseled regarding the high rate of complications associated with surgery.
Objective—To examine age-related efficacy of bone morphogenetic protein (BMP)-2, ascorbate, and dexamethasone as osteogenic inducers in canine marrow-derived stromal cells (MSCs).
Sample Population—Samples of femoral bone marrow obtained from 15 skeletally immature (< 1 year old) and 4 skeletally mature (> 1.5 years old) dogs.
Procedure—First-passage canine MSC cultures were treated with 100 µg of ascorbate phosphate/mL, 10–7M dexamethasone, 100 ng of BMP-2/mL, or a combination of these osteoinducers. On day 6, cultures were harvested for quantitation of alkaline phosphatase (ALP) activity and isolation of RNA to prepare cDNA for real-time polymerase chain reaction analyses of osteoblast markers.
Results—Early markers of osteogenesis were induced in canine MSCs by BMP-2 but not dexamethasone. In young dogs, the combination of BMP- 2 and ascorbate yielded the highest ALP mRNA concentrations and activity. This combination also induced significant increases in mRNA for osteopontin and runt-domain transcription factor 2. In comparison to MSCs from immature dogs, those from mature dogs had diminished ALP activity in response to BMP and ascorbate. Results for cultures treated with 3,4-dehydroproline suggested that ascorbateinduced production of extracellular matrix was important for maximal BMP-2 response in canine MSCs.
Conclusions and Clinical Relevance—BMP-2 was capable of inducing markers of osteogenesis in shortterm cultures of canine MSCs. In MSCs obtained from skeletally immature dogs, ascorbate was required for maximal effects of BMP. These results define optimal conditions for stem cell osteogenesis in dogs and will facilitate development of stem cell–based treatments for dogs with fractures. (Am J Vet Res 2005;66:1729–1737)
Objective—To evaluate clinical findings, complications, and outcome of horses and foals with third metacarpal, third metatarsal, or phalangeal fractures that were treated with transfixation casting.
Design—Retrospective case series.
Animals—29 adult horses and 8 foals with fractures of the third metacarpal or metatarsal bone or the proximal or middle phalanx.
Procedures—Medical records were reviewed, and follow-up information was obtained. Data were analyzed by use of logistic regression models for survival, fracture healing, return to intended use, pin loosening, pin hole lysis, and complications associated with pins.
Results—In 27 of 35 (77%) horses, the fracture healed and the horse survived, including 10 of 15 third metacarpal or metatarsal bone fractures, 11 of 12 proximal phalanx fractures, and 6 of 8 middle phalanx fractures. Four adult horses sustained a fracture through a pin hole. One horse sustained a pathologic unicortical fracture secondary to a pin hole infec-tion. Increasing body weight, fracture involving 2 joints, nondiaphyseal fracture location, and increasing duration until radiographic union were associated with horses not returning to their intended use. After adjusting for body weight, pin loosening was associated with di-aphyseal pin location, pin hole lysis was associated with number of days with a transfixation cast, and pin complications were associated with hand insertion of pins.
Conclusions and Clinical Relevance—Results indicated that transfixation casting can be successful in managing fractures distal to the carpus or tarsus in horses. This technique is most suitable for comminuted fractures of the proximal phalanx but can be used for third metacarpal, third metatarsal, or middle phalanx fractures, with or without internal fixation.
OBJECTIVE To describe clinical use of a locking compression plate (LCP) for proximal interphalangeal joint (PIPJ) arthrodesis in horses and compare outcomes for horses that underwent the procedure as treatment for fracture of the middle phalanx (P2) versus other causes.
DESIGN Retrospective case series.
ANIMALS 29 client-owned horses.
PROCEDURES Medical records of 2 veterinary teaching hospitals from 2008 through 2014 were reviewed to identify horses that underwent PIPJ arthrodesis of 1 limb. Signalment, surgical, and outcome-related variables were recorded. Owners were contacted from 1 to 6 years after surgery to determine rehabilitation time, current use of the horse, and overall owner satisfaction with the procedure. Success was determined on the basis of owner satisfaction and outcome for intended use. Variables of interest were compared statistically between horses that underwent surgery for P2 fracture versus other reasons.
RESULTS 14 horses underwent surgery for treatment of P2 fracture, and 15 had surgery because of osteoarthritis, subluxation, or osteochondrosis. Median convalescent time after surgery (with no riding or unrestricted exercise) was 7 months. Four horses were euthanized; of 23 known alive at follow-up, 22 were not lame, and 18 had returned to their intended use (8 and 10 at higher and lower owner-reported levels of work, respectively). Horses undergoing arthrodesis for reasons other than fracture were significantly more likely to return to their previous level of work. Twenty-two of 24 owners contacted indicated satisfaction with the procedure.
CONCLUSIONS AND CLINICAL RELEVANCE Surgical arthrodesis of the PIPJ was successful in most horses of the study population. Various nuances of the system for fracture repair need to be understood prior to its use.